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1701.00224
Lei Wu
Jinmian Li, Zong-guo Si, Lei Wu, Jason Yue
Central-edge asymmetry as a probe of Higgs-top coupling in $t\bar{t}h$ production at LHC
minor changes, version accepted by PLB
null
10.1016/j.physletb.2018.02.009
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Higgs-top coupling plays a central role in the hierarchy problem and the vacuum stability of the Standard Model (SM). We propose a central-edge asymmetry ($A_{CE}$) to probe the CP violating Higgs-top coupling in dileptonic channel of $t\bar{t}h(\to b\bar{b})$ production at the LHC. We demonstrate that the CP-violating Higgs-top coupling can affect the central-edge asymmetry through distorting $\Delta y_{\ell^+\ell^-}$ distribution because of the contribution of new top charge asymmetric term. Since $\Delta y_{\ell^+\ell^-}$ distribution is frame-independent and has a good discrimination even in boosted regime, we use the jet substructure technique to enhance the observability of the dileptonic channel of $t\bar{t}h$ production. We find that (1) the significance of dileptonic channel of $t\bar{t}h$ production can reach $5\sigma$ for CP phase $\xi=0,\pi/4,\pi/2$ when the luminosity ${\cal L}=795,993,1276$ fb$^{-1}$ at 14 TeV LHC. (2) the central-edge asymmetry $A_{CE}$ show a good discrimination power of CP phase of $t\bar{t}h$ interaction, which are -40.26\%, -26.60\%, -9.47\% for $\xi=0$, $\pi/4$, $ \pi/2$ respectively and are hardly affected by the event selections. Besides, by performing the binned-$\chi^2$ analysis of $\Delta y_{\ell^+\ell^-}$ distribution, we find that the scalar and pseudo-scalar interactions can be distinguished at 95\% C.L. level at 14 TeV HL-LHC.
[ { "created": "Sun, 1 Jan 2017 10:18:59 GMT", "version": "v1" }, { "created": "Sun, 4 Feb 2018 13:39:30 GMT", "version": "v2" } ]
2018-02-14
[ [ "Li", "Jinmian", "" ], [ "Si", "Zong-guo", "" ], [ "Wu", "Lei", "" ], [ "Yue", "Jason", "" ] ]
The Higgs-top coupling plays a central role in the hierarchy problem and the vacuum stability of the Standard Model (SM). We propose a central-edge asymmetry ($A_{CE}$) to probe the CP violating Higgs-top coupling in dileptonic channel of $t\bar{t}h(\to b\bar{b})$ production at the LHC. We demonstrate that the CP-violating Higgs-top coupling can affect the central-edge asymmetry through distorting $\Delta y_{\ell^+\ell^-}$ distribution because of the contribution of new top charge asymmetric term. Since $\Delta y_{\ell^+\ell^-}$ distribution is frame-independent and has a good discrimination even in boosted regime, we use the jet substructure technique to enhance the observability of the dileptonic channel of $t\bar{t}h$ production. We find that (1) the significance of dileptonic channel of $t\bar{t}h$ production can reach $5\sigma$ for CP phase $\xi=0,\pi/4,\pi/2$ when the luminosity ${\cal L}=795,993,1276$ fb$^{-1}$ at 14 TeV LHC. (2) the central-edge asymmetry $A_{CE}$ show a good discrimination power of CP phase of $t\bar{t}h$ interaction, which are -40.26\%, -26.60\%, -9.47\% for $\xi=0$, $\pi/4$, $ \pi/2$ respectively and are hardly affected by the event selections. Besides, by performing the binned-$\chi^2$ analysis of $\Delta y_{\ell^+\ell^-}$ distribution, we find that the scalar and pseudo-scalar interactions can be distinguished at 95\% C.L. level at 14 TeV HL-LHC.
hep-ph/0203191
Xiao-Gang He
X.-G. He, H.-Y. Jin and J. P. Ma
Radiative Decay of $\Upsilon$ into a Scalar Glueball
RevTex, 12 pages no figures. Several numerical errors corrected
Phys.Rev. D66 (2002) 074015
10.1103/PhysRevD.66.074015
null
hep-ph hep-ex
null
We study the radiative decay of $\Upsilon$ into a scalar glueball $\Upsilon \to \gamma G_s$ using QCD factorization. We find that for this process the non-perturbative effects can be factorized into a matrix element well defined in non-relativistic QCD (NRQCD) and the gluon distribution amplitude. The same NRQCD matrix element appears also in leptonic decay of $\Upsilon$ and therefore can be determined from data. In the asymptotic limit the gluon distribution amplitude is known up to a normalization constant. Using a QCD sum-rule calculation for the normalization constant, we obtain $Br(\Upsilon \to \gamma G_s)$ to be in the range $(1\sim 2)\times 10^{-3}$. We also discuss some of the implications for $\Upsilon \to \gamma f_i$ decays. Near future data from CLEO-III can provide crucial information about scalar glueball properties.
[ { "created": "Wed, 20 Mar 2002 07:09:57 GMT", "version": "v1" }, { "created": "Sat, 11 May 2002 00:46:08 GMT", "version": "v2" }, { "created": "Mon, 1 Jul 2002 23:41:28 GMT", "version": "v3" } ]
2009-11-07
[ [ "He", "X. -G.", "" ], [ "Jin", "H. -Y.", "" ], [ "Ma", "J. P.", "" ] ]
We study the radiative decay of $\Upsilon$ into a scalar glueball $\Upsilon \to \gamma G_s$ using QCD factorization. We find that for this process the non-perturbative effects can be factorized into a matrix element well defined in non-relativistic QCD (NRQCD) and the gluon distribution amplitude. The same NRQCD matrix element appears also in leptonic decay of $\Upsilon$ and therefore can be determined from data. In the asymptotic limit the gluon distribution amplitude is known up to a normalization constant. Using a QCD sum-rule calculation for the normalization constant, we obtain $Br(\Upsilon \to \gamma G_s)$ to be in the range $(1\sim 2)\times 10^{-3}$. We also discuss some of the implications for $\Upsilon \to \gamma f_i$ decays. Near future data from CLEO-III can provide crucial information about scalar glueball properties.
1410.4314
Zuo-Tang Liang
Shu-Yi Wei, Kai-bao Chen, Yu-kun Song, Zuo-tang Liang
Leading and higher twist contributions in semi-inclusive e+e- annihilation at high energies
33 pages, 4 figures
Phys. Rev. D 91, 034015 (2015)
10.1103/PhysRevD.91.034015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By applying the collinear expansion to the semi-inclusive hadron production process $e^++e^-\to h+\bar q(jet)+X$ at high energies, we construct a theoretical framework where the leading and higher twist contributions at the leading perturbative QCD can be calculated systematically. With this framework, we calculate the contributions up to twist-3 for spin-0, spin-1/2 and spin-1 hadrons respectively. We present the results for the hadronic tensors, the differential cross sections, the azimuthal asymmetries, and the polarizations of the hadrons.
[ { "created": "Thu, 16 Oct 2014 06:55:29 GMT", "version": "v1" }, { "created": "Sat, 1 Nov 2014 07:25:58 GMT", "version": "v2" } ]
2015-03-05
[ [ "Wei", "Shu-Yi", "" ], [ "Chen", "Kai-bao", "" ], [ "Song", "Yu-kun", "" ], [ "Liang", "Zuo-tang", "" ] ]
By applying the collinear expansion to the semi-inclusive hadron production process $e^++e^-\to h+\bar q(jet)+X$ at high energies, we construct a theoretical framework where the leading and higher twist contributions at the leading perturbative QCD can be calculated systematically. With this framework, we calculate the contributions up to twist-3 for spin-0, spin-1/2 and spin-1 hadrons respectively. We present the results for the hadronic tensors, the differential cross sections, the azimuthal asymmetries, and the polarizations of the hadrons.
2103.13776
Shahin Atashbar Tehrani
Maral Salajegheh, S. Mohammad Moosavi Nejad, S. Atashbar Tehrani
Improved determination of strange distribution function from the global analysis using BHPS model
12 pages, 5 figs , 2 tables
Few-Body Syst. (2021) 62:16
10.1007/s00601-021-01601-8
null
hep-ph
http://creativecommons.org/licenses/by-sa/4.0/
We study the impact of intrinsic strange (IS) component of nucleon sea on the global analysis of parton distribution functions (PDFs) considering a wide range of experimental data. To this aim, we consider two scenarios on the basis of BHPS model results for the IS distribution. In the first scenario, we apply the results presented through the BHPS model and in the second scenario we use its evolved distributions. For each scenarios, we present the limit of the IS probability $ {\cal P}_5^{s\bar{s}} $ for the standard tolerance criteria $ \Delta\chi^2=1 $ and $ 18.112 $ at $ 1\sigma $ and $ 4\sigma $ levels. Our results show that the experimental data can tolerate an IS component with a greater probability $ {\cal P}_5^{s\bar{s}} $ if one employs the second scenario. We obtain $ {\cal P}_5^{s\bar{s}}\approx 0.01 $ and $ {\cal P}_5^{s\bar{s}}\approx 0.025 $ for $ \Delta\chi^2=1 $ and $18.112$, respectively, at the $ 4\sigma $ level. We also calculate the ratio of strange-to-light sea-quark densities $r_s$ in the proton both including and excluding the IS component. Our results show that one can obtain a higher value for the ratio $r_s$ if the IS component is included.
[ { "created": "Thu, 25 Mar 2021 12:00:13 GMT", "version": "v1" } ]
2021-03-26
[ [ "Salajegheh", "Maral", "" ], [ "Nejad", "S. Mohammad Moosavi", "" ], [ "Tehrani", "S. Atashbar", "" ] ]
We study the impact of intrinsic strange (IS) component of nucleon sea on the global analysis of parton distribution functions (PDFs) considering a wide range of experimental data. To this aim, we consider two scenarios on the basis of BHPS model results for the IS distribution. In the first scenario, we apply the results presented through the BHPS model and in the second scenario we use its evolved distributions. For each scenarios, we present the limit of the IS probability $ {\cal P}_5^{s\bar{s}} $ for the standard tolerance criteria $ \Delta\chi^2=1 $ and $ 18.112 $ at $ 1\sigma $ and $ 4\sigma $ levels. Our results show that the experimental data can tolerate an IS component with a greater probability $ {\cal P}_5^{s\bar{s}} $ if one employs the second scenario. We obtain $ {\cal P}_5^{s\bar{s}}\approx 0.01 $ and $ {\cal P}_5^{s\bar{s}}\approx 0.025 $ for $ \Delta\chi^2=1 $ and $18.112$, respectively, at the $ 4\sigma $ level. We also calculate the ratio of strange-to-light sea-quark densities $r_s$ in the proton both including and excluding the IS component. Our results show that one can obtain a higher value for the ratio $r_s$ if the IS component is included.
1212.3168
Maxim Chernodub
M. N. Chernodub, Jos Van Doorsselaere, Tigran Kalaydzhyan, Henri Verschelde
On chromoelectric (super)conductivity of the Yang-Mills vacuum
4 pages, 2 figures; v2: misprints corrected, matches published version
Phys. Lett. B 730 (2014) 63
10.1016/j.physletb.2014.01.029
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that in the Copenhagen (``spaghetti'') picture of the QCD vacuum the chromomagnetic flux tubes exhibit chromoelectric superconductivity. We show that the superconducting chromoelectric currents in the tubes may be induced by the topological charge density.
[ { "created": "Thu, 13 Dec 2012 13:34:14 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2014 09:47:18 GMT", "version": "v2" } ]
2014-01-29
[ [ "Chernodub", "M. N.", "" ], [ "Van Doorsselaere", "Jos", "" ], [ "Kalaydzhyan", "Tigran", "" ], [ "Verschelde", "Henri", "" ] ]
We argue that in the Copenhagen (``spaghetti'') picture of the QCD vacuum the chromomagnetic flux tubes exhibit chromoelectric superconductivity. We show that the superconducting chromoelectric currents in the tubes may be induced by the topological charge density.
hep-ph/0107156
Alessandro Strumia
Andre'de Gouvea, Gian Francesco Giudice, Alessandro Strumia, Kazuhiro Tobe
Phenomenological implications of neutrinos in extra dimensions
20 pages, 2 figures. Version 2: we added a note about the NuTeV anomaly
Nucl.Phys.B623:395-420,2002
10.1016/S0550-3213(01)00621-6
IFUP-TH/18-2001 and CERN-TH/2001-184
hep-ph
null
Standard Model singlet neutrinos propagating in extra dimensions induce small Dirac neutrino masses. While it seems rather unlikely that their Kaluza-Klein excitations directly participate in the observed neutrino oscillations, their virtual exchange may lead to detectable signatures in future neutrino experiments and in rare charged lepton processes. We show how these effects can be described by specific dimension-six effective operators and discuss their experimental signals.
[ { "created": "Fri, 13 Jul 2001 16:51:10 GMT", "version": "v1" }, { "created": "Thu, 1 Nov 2001 17:59:49 GMT", "version": "v2" } ]
2010-05-28
[ [ "Gouvea", "Andre'de", "" ], [ "Giudice", "Gian Francesco", "" ], [ "Strumia", "Alessandro", "" ], [ "Tobe", "Kazuhiro", "" ] ]
Standard Model singlet neutrinos propagating in extra dimensions induce small Dirac neutrino masses. While it seems rather unlikely that their Kaluza-Klein excitations directly participate in the observed neutrino oscillations, their virtual exchange may lead to detectable signatures in future neutrino experiments and in rare charged lepton processes. We show how these effects can be described by specific dimension-six effective operators and discuss their experimental signals.
1811.07634
Haiqing Zhou
Hui-Yun Cao, Hai-Qing Zhou
Correction to the energy spectrum of $^1S_0$ heavy quarkonia due to two-gluon annihilation effect
null
Phys. Rev. D 99, 074007 (2019)
10.1103/PhysRevD.99.074007
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, the non-relativistic asymptotic behavior of the transition $q\overline{q}\rightarrow2g\rightarrow q\overline{q}$ in the $^1S_0$ channel is discussed. Different with the usual calculation which expands the physical amplitude around the quark anti-quark threshold, we take the quark anti-quark pairs as off shell and only expand the expression on the three-dimensional momenta of the quarks and anti-quarks. We calculate the results to order 6. The imagine part of the results after applying the on shell conditions can reproduce the non-relativistic QCD (NRQCD) results in leading order of $\alpha_s$. The real part of the results can be used to estimate the mass shift of the $^1S_0$ heavy quark anti-quark system due to the $2g$ annihilation effect. The results can also be used to estimate the energy shifts of the positronium system due to the two-photon annihilation.
[ { "created": "Mon, 19 Nov 2018 12:01:26 GMT", "version": "v1" } ]
2019-04-17
[ [ "Cao", "Hui-Yun", "" ], [ "Zhou", "Hai-Qing", "" ] ]
In this work, the non-relativistic asymptotic behavior of the transition $q\overline{q}\rightarrow2g\rightarrow q\overline{q}$ in the $^1S_0$ channel is discussed. Different with the usual calculation which expands the physical amplitude around the quark anti-quark threshold, we take the quark anti-quark pairs as off shell and only expand the expression on the three-dimensional momenta of the quarks and anti-quarks. We calculate the results to order 6. The imagine part of the results after applying the on shell conditions can reproduce the non-relativistic QCD (NRQCD) results in leading order of $\alpha_s$. The real part of the results can be used to estimate the mass shift of the $^1S_0$ heavy quark anti-quark system due to the $2g$ annihilation effect. The results can also be used to estimate the energy shifts of the positronium system due to the two-photon annihilation.
0812.0994
David Blaschke
D.B. Blaschke, M.P. Dabrowski, V.V. Dmitriev, S.A. Smolyansky,
Kinetic description of W and Z boson creation in the early universe
4 pages, contribution to the Proceedings of the XIX Int. Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and QCD", Dubna, 29.9.-4.10.2008
null
null
null
hep-ph astro-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an alternative mechanism for the production of the cosmic microwave background (CMB) radiation. It is basically due to vacuum pair creation (VPC) of vector bosons (W and Z) as a consequence of a rapid W and Z mass generation during the electroweak phase transition in the early Universe. The mechanism is as follows: after their pair crreation, the vector bosons may either annihilate directly into photons or decay into leptons and quarks which subsequently annihilate as lepton-antilepton and quark-antiquark pairs into photons. Preliminary estimates show that the number of CMB photons obtained this way can be sufficient to explain the presently observed CMB photon density. In this contribution we present an exactly soluble model for vacuum pair creation kinetics.
[ { "created": "Thu, 4 Dec 2008 17:55:46 GMT", "version": "v1" } ]
2008-12-08
[ [ "Blaschke", "D. B.", "" ], [ "Dabrowski", "M. P.", "" ], [ "Dmitriev", "V. V.", "" ], [ "Smolyansky", "S. A.", "" ] ]
We consider an alternative mechanism for the production of the cosmic microwave background (CMB) radiation. It is basically due to vacuum pair creation (VPC) of vector bosons (W and Z) as a consequence of a rapid W and Z mass generation during the electroweak phase transition in the early Universe. The mechanism is as follows: after their pair crreation, the vector bosons may either annihilate directly into photons or decay into leptons and quarks which subsequently annihilate as lepton-antilepton and quark-antiquark pairs into photons. Preliminary estimates show that the number of CMB photons obtained this way can be sufficient to explain the presently observed CMB photon density. In this contribution we present an exactly soluble model for vacuum pair creation kinetics.
1804.06358
Jian Wang
Hai Tao Li, Jian Wang
Next-to-next-to-leading order $N$-jettiness soft function for $tW$ production
14 pages, 3 figures, published version in PLB
Phys. Lett. B 784 (2018) 397
10.1016/j.physletb.2018.08.019
TUM-HEP-1137/18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the $N$-jettiness soft function for $tW$ production up to next-to-next-to-leading order in QCD, which is an important ingredient of the $N$-jettiness subtraction method for predicting the differential cross sections of massive coloured particle productions. The divergent parts of the results have been checked using the renormalization group equations controlled by the soft anomalous dimension.
[ { "created": "Tue, 17 Apr 2018 16:31:15 GMT", "version": "v1" }, { "created": "Tue, 28 Aug 2018 06:55:37 GMT", "version": "v2" } ]
2018-08-29
[ [ "Li", "Hai Tao", "" ], [ "Wang", "Jian", "" ] ]
We calculate the $N$-jettiness soft function for $tW$ production up to next-to-next-to-leading order in QCD, which is an important ingredient of the $N$-jettiness subtraction method for predicting the differential cross sections of massive coloured particle productions. The divergent parts of the results have been checked using the renormalization group equations controlled by the soft anomalous dimension.
hep-ph/9712482
Bernd Kniehl
J. Binnewies (Hamburg University), B.A. Kniehl (MPI Munich), G. Kramer (Hamburg University)
Predictions for D^*+- Photoproduction at HERA with New Fragmentation Functions from LEP1
23 pages (Latex), 7 figures (Postscript)
Phys.Rev.D58:014014,1998
10.1103/PhysRevD.58.014014
DESY 97-241, MPI/PhT/97-88
hep-ph hep-ex
null
We present new sets of nonperturbative fragmentation functions for D^*+- mesons, both at leading and next-to-leading order in the MS-bar factorization scheme with five massless quark flavors. They are determined by fitting the latest OPAL and ALEPH data on inclusive D^*+- production in e^+e^- annihilation. We take the charm-quark fragmentation function to be of the form proposed by Peterson et al. and thus obtain new values of the epsilon_c parameter, which are specific for our choice of factorization scheme. With these fragmentation functions, recent data on inclusive D^*+- photoproduction in ep collisions at HERA are reasonably well reproduced.
[ { "created": "Mon, 22 Dec 1997 14:33:30 GMT", "version": "v1" } ]
2011-01-25
[ [ "Binnewies", "J.", "", "Hamburg University" ], [ "Kniehl", "B. A.", "", "MPI Munich" ], [ "Kramer", "G.", "", "Hamburg University" ] ]
We present new sets of nonperturbative fragmentation functions for D^*+- mesons, both at leading and next-to-leading order in the MS-bar factorization scheme with five massless quark flavors. They are determined by fitting the latest OPAL and ALEPH data on inclusive D^*+- production in e^+e^- annihilation. We take the charm-quark fragmentation function to be of the form proposed by Peterson et al. and thus obtain new values of the epsilon_c parameter, which are specific for our choice of factorization scheme. With these fragmentation functions, recent data on inclusive D^*+- photoproduction in ep collisions at HERA are reasonably well reproduced.
hep-ph/0412399
Vladimir Zoller
V.R. Zoller (ITEP, Moscow)
Triple-pomeron dynamics: valence vs. glue
4 pages, 1 Postscript figure, To appear in Proc. of DIFFRACTION 2004, Int. Workshop on Diffraction in High-Energy Physics, Cala Gonone, Sardinia, Italy, Sept. 18-23, 2004
null
10.1016/j.nuclphysbps.2005.02.099
null
hep-ph
null
Three pomerons are known to couple via the gluon loop and interactions of this kind which are responsible for high-mass diffraction are described in terms of the gluonic structure function of the QCD pomeron. We show that the triple-pomeron coupling via the light quark loop associated with the ``valence'' in the pomeron is of the same strength as the purely gluonic coupling. The large $Q^2$ behavior of this new contribution is described by the DLLA evolution from the non-perturbative $f\bar f$ valence state of the pomeron. Numerical estimates of the high-mass diffraction structure functions based on the consistent account of both couplings are in good agreement with experimental data.
[ { "created": "Tue, 28 Dec 2004 13:55:01 GMT", "version": "v1" } ]
2009-11-10
[ [ "Zoller", "V. R.", "", "ITEP, Moscow" ] ]
Three pomerons are known to couple via the gluon loop and interactions of this kind which are responsible for high-mass diffraction are described in terms of the gluonic structure function of the QCD pomeron. We show that the triple-pomeron coupling via the light quark loop associated with the ``valence'' in the pomeron is of the same strength as the purely gluonic coupling. The large $Q^2$ behavior of this new contribution is described by the DLLA evolution from the non-perturbative $f\bar f$ valence state of the pomeron. Numerical estimates of the high-mass diffraction structure functions based on the consistent account of both couplings are in good agreement with experimental data.
hep-ph/0202092
Gerhard Buchalla
Gerhard Buchalla
Heavy Quark Theory
50 pages, Lectures given at the 55th Scottish Universities Summer School in Physics, 7-23 August 2001, St. Andrews, Scotland
null
null
CERN-TH/2002-018
hep-ph
null
These lectures describe the most important theoretical methods in b-physics. We discuss the formalism of effective weak Hamiltonians, heavy quark effective theory, the heavy quark expansion for inclusive decays of b-hadrons and, finally, the more recent ideas of QCD factorization for exclusive nonleptonic B decays. While the main emphasis is put on introducing the basic theoretical concepts, some key applications in phenomenology are also presented for illustration.
[ { "created": "Sat, 9 Feb 2002 23:06:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Buchalla", "Gerhard", "" ] ]
These lectures describe the most important theoretical methods in b-physics. We discuss the formalism of effective weak Hamiltonians, heavy quark effective theory, the heavy quark expansion for inclusive decays of b-hadrons and, finally, the more recent ideas of QCD factorization for exclusive nonleptonic B decays. While the main emphasis is put on introducing the basic theoretical concepts, some key applications in phenomenology are also presented for illustration.
1403.4582
Zahra Ghalenovi
Zahra Ghalenovi, Ali Akbar Rajabi, Si-xue Qin, Dirk. H. Rischke
Ground-State Masses and Magnetic Moments of Heavy Baryons
null
Mod Phys Lett A 29 (2014) 1460106
10.1142/S0217732314501065
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study single, double, and triple heavy-flavor baryons using the hypercentral approach in the framework of the non-relativistic quark model. Considering two different confining potentials and an improved form of the hyperfine interaction, we calculate the ground-state masses of heavy baryons and also the ground-state magnetic moments of single charm and beauty baryons with J^(P) =3/2^(+). The obtained results are in good agreement with experimental data and those of other works.
[ { "created": "Tue, 18 Mar 2014 19:32:25 GMT", "version": "v1" } ]
2021-11-09
[ [ "Ghalenovi", "Zahra", "" ], [ "Rajabi", "Ali Akbar", "" ], [ "Qin", "Si-xue", "" ], [ "Rischke", "Dirk. H.", "" ] ]
In this work we study single, double, and triple heavy-flavor baryons using the hypercentral approach in the framework of the non-relativistic quark model. Considering two different confining potentials and an improved form of the hyperfine interaction, we calculate the ground-state masses of heavy baryons and also the ground-state magnetic moments of single charm and beauty baryons with J^(P) =3/2^(+). The obtained results are in good agreement with experimental data and those of other works.
0705.2193
Kirill Tuchin
Kirill Tuchin
Forward hadron production in high energy pA collisions: from RHIC to LHC
16 pages, 8 figures; discussion added and a few typos corrected
Nucl.Phys.A798:61-73,2008
10.1016/j.nuclphysa.2007.10.008
RBRC-670
hep-ph nucl-ex nucl-th
null
We present a calculation of Pi, D and B mesons production at RHIC and LHC energies based upon the KKT model of gluon saturation. We discuss dependence of the nuclear modification factor on rapidity and transverse momentum.
[ { "created": "Tue, 15 May 2007 17:28:45 GMT", "version": "v1" }, { "created": "Wed, 14 Nov 2007 20:09:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Tuchin", "Kirill", "" ] ]
We present a calculation of Pi, D and B mesons production at RHIC and LHC energies based upon the KKT model of gluon saturation. We discuss dependence of the nuclear modification factor on rapidity and transverse momentum.
0908.2570
Schoeffel Laurent
Laurent Schoeffel (CEA Saclay, Irfu/SPP)
GPDs at HERA and perspectives at COMPASS
3 pages, 1 figure, proceedings of the 2009 Europhysics Conference on High Energy Physics, 16-22 July 2009 Krakow, Poland
PoS EPS-HEP2009 2009:337,2009
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measurements of the deep-inelastic scattering (DIS) of leptons and nucleons, $e+p\to e+X$, allow the extraction of Parton Distribution Functions (PDFs) which describe the longitudinal momentum carried by the quarks, anti-quarks and gluons that make up the fast-moving nucleons. While PDFs provide crucial input to perturbative Quantum Chromodynamic (QCD) calculations of processes involving hadrons, they do not provide a complete picture of the partonic structure of nucleons. In particular, PDFs contain neither information on the correlations between partons nor on their transverse motion. Hard exclusive processes, in which the nucleon remains intact, have emerged in recent years as prime candidates to complement this essentially one dimentional picture. The simplest exclusive process is the deeply virtual Compton scattering (DVCS) or exclusive production of real photon, $e + p \to e + \gamma + p$. This process is of particular interest as it has both a clear experimental signature and is calculable in perturbative QCD. The DVCS reaction can be regarded as the elastic scattering of the virtual photon off the proton via a colourless exchange, producing a real photon in the final state. In the Bjorken scaling regime, QCD calculations assume that the exchange involves two partons, having different longitudinal and transverse momenta, in a colourless configuration. These unequal momenta or skewing are a consequence of the mass difference between the incoming virtual photon and the outgoing real photon. This skewedness effect can be interpreted in the context of generalised parton distributions (GPDs). In this proceeding, we examine typical measurements from HERA and prospects for COMPASS at CERN, that can bring new insights on the quarks/gluons imaging of the nucleon.
[ { "created": "Tue, 18 Aug 2009 13:27:26 GMT", "version": "v1" } ]
2014-11-20
[ [ "Schoeffel", "Laurent", "", "CEA Saclay, Irfu/SPP" ] ]
Measurements of the deep-inelastic scattering (DIS) of leptons and nucleons, $e+p\to e+X$, allow the extraction of Parton Distribution Functions (PDFs) which describe the longitudinal momentum carried by the quarks, anti-quarks and gluons that make up the fast-moving nucleons. While PDFs provide crucial input to perturbative Quantum Chromodynamic (QCD) calculations of processes involving hadrons, they do not provide a complete picture of the partonic structure of nucleons. In particular, PDFs contain neither information on the correlations between partons nor on their transverse motion. Hard exclusive processes, in which the nucleon remains intact, have emerged in recent years as prime candidates to complement this essentially one dimentional picture. The simplest exclusive process is the deeply virtual Compton scattering (DVCS) or exclusive production of real photon, $e + p \to e + \gamma + p$. This process is of particular interest as it has both a clear experimental signature and is calculable in perturbative QCD. The DVCS reaction can be regarded as the elastic scattering of the virtual photon off the proton via a colourless exchange, producing a real photon in the final state. In the Bjorken scaling regime, QCD calculations assume that the exchange involves two partons, having different longitudinal and transverse momenta, in a colourless configuration. These unequal momenta or skewing are a consequence of the mass difference between the incoming virtual photon and the outgoing real photon. This skewedness effect can be interpreted in the context of generalised parton distributions (GPDs). In this proceeding, we examine typical measurements from HERA and prospects for COMPASS at CERN, that can bring new insights on the quarks/gluons imaging of the nucleon.
2309.03553
Francesco Sannino
Vigilante Di Risi, Davide Iacobacci, Francesco Sannino
$\Lambda_b \rightarrow \Lambda_c^{\ast}$ at $1\,/\,m_c^2$ heavy quark order
Revised version with typos corrected. 66 pages, one figure with 10 subfigures
null
null
null
hep-ph hep-lat
http://creativecommons.org/licenses/by/4.0/
We systematically compute the $\Lambda_b(p, s_b) \to \Lambda_c(2595)^+$ and $\Lambda_b(p, s_b) \to \Lambda_c(2625)^+$ form factors within the Heavy Quark Effective Theory (HQET) framework including $\mathcal{O}(1/m_c^2)$. Besides taking into account the Standard Model-like vector and axial contributions, we further determine tensor and pseudo-tensor form factors. Our work constitutes a step forward with respect to previous analyses allowing for a comprehensive study of the matrix element parametrisation stemming from the HQET formalism. Finally, we demonstrate that the resulting form factors agree well with lattice Quantum Chromodynamics (LQCD) determinations stressing the need and relevance of the newly derived $1/m_c^2$ corrections.
[ { "created": "Thu, 7 Sep 2023 08:21:57 GMT", "version": "v1" }, { "created": "Thu, 4 Apr 2024 13:04:41 GMT", "version": "v2" } ]
2024-04-05
[ [ "Di Risi", "Vigilante", "" ], [ "Iacobacci", "Davide", "" ], [ "Sannino", "Francesco", "" ] ]
We systematically compute the $\Lambda_b(p, s_b) \to \Lambda_c(2595)^+$ and $\Lambda_b(p, s_b) \to \Lambda_c(2625)^+$ form factors within the Heavy Quark Effective Theory (HQET) framework including $\mathcal{O}(1/m_c^2)$. Besides taking into account the Standard Model-like vector and axial contributions, we further determine tensor and pseudo-tensor form factors. Our work constitutes a step forward with respect to previous analyses allowing for a comprehensive study of the matrix element parametrisation stemming from the HQET formalism. Finally, we demonstrate that the resulting form factors agree well with lattice Quantum Chromodynamics (LQCD) determinations stressing the need and relevance of the newly derived $1/m_c^2$ corrections.
hep-ph/9402266
Wim deBoer
W. de Boer (University Karlsruhe)
Grand Unified Theories and Supersymmetry in Particle Physics and Cosmology
IEKP-KA/94-01 preprint, 103 pages, now figures with reduced size
Prog.Part.Nucl.Phys.33:201-302,1994
10.1016/0146-6410(94)90045-0
IEKP-KA/94-01
hep-ph
null
A review is given on the consistency checks of GUT, which unify the electroweak and strong nuclear forces into a single theory. Such theories predict a new kind of force, which could provide answers to several open questions in cosmology. The possible role of such a ``primeval'' force will be discussed in the framework of the Big Bang Theory. Although such a force cannot be observed directly, there are several predictions of GUT's, which can be verified at low energies. The MSSM distinguishes itself from other GUT's by a successful prediction of many unrelated phenomena with a minimum number of parameters. Among them: a) Unification of the couplings constants; b) Unification of the masses; c) Existence of dark matter; d) Proton decay; e) electroweak symmetry breaking at a scale far below the unification scale. A combined fit shows that indeed the MSSM model can satisfy all these constraints simultaneously. The corresponding constraints on the as yet unknown top mass, the strong coupling constant, and all SUSY masses are given within the minimal model, taking into account the complete second order RGE's for the couplings and the one-loop corrected Higgs potential for the calculation of the Z and the Higgs masses.
[ { "created": "Thu, 10 Feb 1994 11:08:33 GMT", "version": "v1" }, { "created": "Fri, 18 Mar 1994 12:24:29 GMT", "version": "v2" }, { "created": "Mon, 21 Mar 1994 09:58:46 GMT", "version": "v3" }, { "created": "Thu, 26 May 1994 12:59:57 GMT", "version": "v4" }, { "c...
2010-01-22
[ [ "de Boer", "W.", "", "University Karlsruhe" ] ]
A review is given on the consistency checks of GUT, which unify the electroweak and strong nuclear forces into a single theory. Such theories predict a new kind of force, which could provide answers to several open questions in cosmology. The possible role of such a ``primeval'' force will be discussed in the framework of the Big Bang Theory. Although such a force cannot be observed directly, there are several predictions of GUT's, which can be verified at low energies. The MSSM distinguishes itself from other GUT's by a successful prediction of many unrelated phenomena with a minimum number of parameters. Among them: a) Unification of the couplings constants; b) Unification of the masses; c) Existence of dark matter; d) Proton decay; e) electroweak symmetry breaking at a scale far below the unification scale. A combined fit shows that indeed the MSSM model can satisfy all these constraints simultaneously. The corresponding constraints on the as yet unknown top mass, the strong coupling constant, and all SUSY masses are given within the minimal model, taking into account the complete second order RGE's for the couplings and the one-loop corrected Higgs potential for the calculation of the Z and the Higgs masses.
hep-ph/9703406
Han-Werner Hammer
H.-W. Hammer (1 and 2) and M.J. Ramsey-Musolf (1 and 3) ((1) INT, U. of Washington, (2) Inst. f. Kernphysik, U. Mainz, (3) U. of Connecticut)
Nucleon Vector Strangeness Form Factors: Multi-pion Continuum and the OZI Rule
18 pages, LaTex, 4 PS figures, uses epsf.sty, rotate.sty, revised to include 3\pi -> \omega resonance and e^+ e^- data
Phys.Lett. B416 (1998) 5-15
10.1016/S0370-2693(97)01322-1
INT DOE/ER/40561-317-INT97-00-169 and MKPH-T-97-10
hep-ph nucl-th
null
We estimate the 3 \pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \pi <----> \rho \pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to that of typical OZI-allowed contributions. We also study the isoscalar electromagnetic form factors, and find that the presence of a \rho \pi resonance in the multi-pion continuum may generate an appreciable contribution.
[ { "created": "Tue, 25 Mar 1997 01:24:58 GMT", "version": "v1" }, { "created": "Tue, 22 Jul 1997 21:09:22 GMT", "version": "v2" } ]
2009-10-30
[ [ "Hammer", "H. -W.", "", "1 and 2" ], [ "Ramsey-Musolf", "M. J.", "", "1 and 3" ] ]
We estimate the 3 \pi continuum contribution to the nucleon strange quark vector current form factors, including the effect of a 3 \pi <----> \rho \pi resonance. We find the magnitude of this OZI-violating contribution to be comparable to that of typical OZI-allowed contributions. We also study the isoscalar electromagnetic form factors, and find that the presence of a \rho \pi resonance in the multi-pion continuum may generate an appreciable contribution.
1505.07950
Fuminobu Takahashi
Fuminobu Takahashi
Inflation and Higgs
6 pages, 1 figure. Presented at the 2nd Toyama International Workshop on "Higgs as a Probe of New Physics 2015" (HPNP2015), Toyama, Japan, February 11-15, 2015. Author's note: This contribution is based on 1006.2801, 1008.2956, 1008.4457, 1108.0070, 1203.0323, 1403.4132, 1408.5556, and 1502.03725
null
null
TU-996
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We briefly review several Higgs inflation models and discuss their cosmological implications. We first classify the inflation models according to the predicted value of the tensor-to-scalar ratio: (i) $r = {\cal O}(0.01-0.1)$, (ii) $r = {\cal O}(10^{-3})$, and (iii) $r \ll 10^{-3}$. For each case we study (i) the Higgs inflation with a running kinetic term, (ii) the Higgs inflation with a non-minimal coupling to gravity, and (iii) the $B-L$ Higgs inflation. In the last case we introduce supersymmetry to suppress the Coleman-Weinberg corrections for successful inflation, and derive the upper bound on the SUSY breaking scale. Interestingly, the SUSY $B-L$ Higgs inflation requires the SUSY breaking scale of order ${\cal O}(100)$\,TeV to explain the observed spectral index. We briefly discuss a topological Higgs inflation which explains the origin of the standard model near-criticality. We also mention the possibility of Higgs domain walls and the gravitational waves emitted by the collapsing domain walls.
[ { "created": "Fri, 29 May 2015 07:28:50 GMT", "version": "v1" } ]
2015-06-01
[ [ "Takahashi", "Fuminobu", "" ] ]
We briefly review several Higgs inflation models and discuss their cosmological implications. We first classify the inflation models according to the predicted value of the tensor-to-scalar ratio: (i) $r = {\cal O}(0.01-0.1)$, (ii) $r = {\cal O}(10^{-3})$, and (iii) $r \ll 10^{-3}$. For each case we study (i) the Higgs inflation with a running kinetic term, (ii) the Higgs inflation with a non-minimal coupling to gravity, and (iii) the $B-L$ Higgs inflation. In the last case we introduce supersymmetry to suppress the Coleman-Weinberg corrections for successful inflation, and derive the upper bound on the SUSY breaking scale. Interestingly, the SUSY $B-L$ Higgs inflation requires the SUSY breaking scale of order ${\cal O}(100)$\,TeV to explain the observed spectral index. We briefly discuss a topological Higgs inflation which explains the origin of the standard model near-criticality. We also mention the possibility of Higgs domain walls and the gravitational waves emitted by the collapsing domain walls.
hep-ph/0312163
Kevork Abazajian
Kevork Abazajian
The Cosmological Energy Density of Neutrinos from Oscillation Measurements
4 pages, Proceedings of NuFact 03, 5th International Workshop on Neutrino Factories & Superbeams, 5-11 June 2003, Columbia University, New York
null
10.1063/1.1818410
null
hep-ph astro-ph
null
The emerging structure of the neutrino mass matrix, when combined with the primordial element abundances, places the most stringent constraint on the flavor asymmetries in the cosmological neutrino background and therefore its energy density. I review the mechanism of synchronized neutrino oscillations in the an early universe with degenerate (asymmetric) neutrino and antineutrino densities and the implications of refined measurements of neutrino parameters.
[ { "created": "Fri, 12 Dec 2003 01:38:26 GMT", "version": "v1" } ]
2009-11-10
[ [ "Abazajian", "Kevork", "" ] ]
The emerging structure of the neutrino mass matrix, when combined with the primordial element abundances, places the most stringent constraint on the flavor asymmetries in the cosmological neutrino background and therefore its energy density. I review the mechanism of synchronized neutrino oscillations in the an early universe with degenerate (asymmetric) neutrino and antineutrino densities and the implications of refined measurements of neutrino parameters.
1909.01753
Giancarlo Rossi
Giancarlo Rossi, Gabriele Veneziano
$P_c$ Photo-production And Decay
6 pages, 11 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The 2015 LHCb discovery of a structure (denoted by $P_c^+$) decaying in $J/\psi \,p$ and conjectured to be a penta-quark state, has triggered a renewed interest in the question of possible existence of multi-quark states not predicted by the naive quark model. In this talk we present some considerations on $P_c$ photo-production experiments, aimed at testing its multi-quark interpretation in the framework of a 40-years-old string-junction picture that allows a unified description of baryons, tetra-, and penta-quark states.
[ { "created": "Wed, 4 Sep 2019 12:51:22 GMT", "version": "v1" } ]
2019-09-05
[ [ "Rossi", "Giancarlo", "" ], [ "Veneziano", "Gabriele", "" ] ]
The 2015 LHCb discovery of a structure (denoted by $P_c^+$) decaying in $J/\psi \,p$ and conjectured to be a penta-quark state, has triggered a renewed interest in the question of possible existence of multi-quark states not predicted by the naive quark model. In this talk we present some considerations on $P_c$ photo-production experiments, aimed at testing its multi-quark interpretation in the framework of a 40-years-old string-junction picture that allows a unified description of baryons, tetra-, and penta-quark states.
0711.1049
Jacobo L\'opez-Pav\'on
J.Lopez-Pavon
Non-unitary leptonic mixing and CP-violation
3 pages, 2 eps figures, based on talk given at NuFact07, Okayama, Japan, 6-11 August 2007; prepared using LaTeX package for publication in the AIP Conference Proceedings
AIPConf.Proc.981:219-221,2008
10.1063/1.2898939
null
hep-ph
null
Some theories of new physics accounting for neutrino masses can give rise to a low-energy non-unitary leptonic mixing matrix. It is shown that the CP-asymmetries in the $\nu_\mu\to \nu_\tau$ channel are an excellent probe of such new physics. In adition, we clarify the relationship betweeen our framework and the so called "non-standard neutrino interactions" scenarios: the sensitivities explored here apply as well to such constructions, except for extremely fine-tuned cancellations.
[ { "created": "Wed, 7 Nov 2007 14:54:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lopez-Pavon", "J.", "" ] ]
Some theories of new physics accounting for neutrino masses can give rise to a low-energy non-unitary leptonic mixing matrix. It is shown that the CP-asymmetries in the $\nu_\mu\to \nu_\tau$ channel are an excellent probe of such new physics. In adition, we clarify the relationship betweeen our framework and the so called "non-standard neutrino interactions" scenarios: the sensitivities explored here apply as well to such constructions, except for extremely fine-tuned cancellations.
hep-ph/0503130
Carlos E. Yaguna
Graciela Gelmini (UCLA), Shmuel Nussinov (Tel Aviv U.), Carlos E. Yaguna (UCLA)
On photon splitting in theories with Lorentz invariance violation
3 pages; v2: discussion enlarged, results unchanged
JCAP 0506 (2005) 012
10.1088/1475-7516/2005/06/012
null
hep-ph
null
In a model with Lorentz invariance violation implemented through modified dispersion relations, we estimate the rate for the decay process gamma -> 3 gamma and find that it provides a relevant bound on Lorentz invariance violation.
[ { "created": "Mon, 14 Mar 2005 17:45:44 GMT", "version": "v1" }, { "created": "Mon, 23 May 2005 18:50:06 GMT", "version": "v2" } ]
2009-11-11
[ [ "Gelmini", "Graciela", "", "UCLA" ], [ "Nussinov", "Shmuel", "", "Tel Aviv U." ], [ "Yaguna", "Carlos E.", "", "UCLA" ] ]
In a model with Lorentz invariance violation implemented through modified dispersion relations, we estimate the rate for the decay process gamma -> 3 gamma and find that it provides a relevant bound on Lorentz invariance violation.
1506.07685
Jessica Elevant
Jessica Elevant, Thomas Schwetz
On the determination of the leptonic CP phase
25 pages, 12 figures. Matches version which is to appear in JHEP. New appendix with the first anti-neutrino results from T2K is added
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The combination of data from long-baseline and reactor oscillation experiments leads to a preference of the leptonic CP phase $\delta_{\rm CP}$ in the range between $\pi$ and $2\pi$. We study the statistical significance of this hint by performing a Monte Carlo simulation of the relevant data. We find that the distribution of the standard test statistic used to derive confidence intervals for $\delta_{\rm CP}$ is highly non-Gaussian and depends on the unknown true values of $\theta_{23}$ and the neutrino mass ordering. Values of $\delta_{\rm CP}$ around $\pi/2$ are disfavored at between $2\sigma$ and $3\sigma$, depending on the unknown true values of $\theta_{23}$ and the mass ordering. Typically the standard $\chi^2$ approximation leads to over-coverage of the confidence intervals for $\delta_{\rm CP}$. For the 2-dimensional confidence region in the ($\delta_{\rm CP},\theta_{23}$) plane the usual $\chi^2$ approximation is better justified. The 2-dimensional region does not include the value $\delta_{\rm CP} = \pi/2$ up to the 86.3\% (89.2\%)~CL assuming a true normal (inverted) mass ordering. Furthermore, we study the sensitivity to $\delta_{\rm CP}$ and $\theta_{23}$ of an increased exposure of the T2K experiment, roughly a factor 12 larger than the current exposure and including also anti-neutrino data. Also in this case deviations from Gaussianity may be significant, especially if the mass ordering is unknown.
[ { "created": "Thu, 25 Jun 2015 10:01:04 GMT", "version": "v1" }, { "created": "Tue, 11 Aug 2015 15:22:58 GMT", "version": "v2" } ]
2015-08-12
[ [ "Elevant", "Jessica", "" ], [ "Schwetz", "Thomas", "" ] ]
The combination of data from long-baseline and reactor oscillation experiments leads to a preference of the leptonic CP phase $\delta_{\rm CP}$ in the range between $\pi$ and $2\pi$. We study the statistical significance of this hint by performing a Monte Carlo simulation of the relevant data. We find that the distribution of the standard test statistic used to derive confidence intervals for $\delta_{\rm CP}$ is highly non-Gaussian and depends on the unknown true values of $\theta_{23}$ and the neutrino mass ordering. Values of $\delta_{\rm CP}$ around $\pi/2$ are disfavored at between $2\sigma$ and $3\sigma$, depending on the unknown true values of $\theta_{23}$ and the mass ordering. Typically the standard $\chi^2$ approximation leads to over-coverage of the confidence intervals for $\delta_{\rm CP}$. For the 2-dimensional confidence region in the ($\delta_{\rm CP},\theta_{23}$) plane the usual $\chi^2$ approximation is better justified. The 2-dimensional region does not include the value $\delta_{\rm CP} = \pi/2$ up to the 86.3\% (89.2\%)~CL assuming a true normal (inverted) mass ordering. Furthermore, we study the sensitivity to $\delta_{\rm CP}$ and $\theta_{23}$ of an increased exposure of the T2K experiment, roughly a factor 12 larger than the current exposure and including also anti-neutrino data. Also in this case deviations from Gaussianity may be significant, especially if the mass ordering is unknown.
2210.14176
Abhijit Kumar Saha
Anish Ghoshal, Dibyendu Nanda, Abhijit Kumar Saha
CMB imprints of high scale non-thermal leptogenesis
Accepted for Publication in Physics Letter B
Phys.Lett.B 849 (2024) 138484
10.1016/j.physletb.2024.138484
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We study the imprints of high scale non-thermal leptogenesis on cosmic microwave background (CMB) from the measurements of inflationary spectral index ($n_s$) and tensor-to-scalar ratio ($r$), which otherwise is inaccessible to the conventional laboratory experiments. We argue that non-thermal production of baryon (lepton) asymmetry from subsequent decays of inflaton to heavy right-handed neutrinos (RHN) and RHN to SM leptons is sensitive to the reheating dynamics in the early Universe after the end of inflation. Such dependence provides detectable imprints on the $n_s-r$ plane which is well constrained by the Planck experiment. We investigate two separate cases, (I) inflaton decays to radiation dominantly and (II) inflaton decays to RHN dominantly which further decays to the SM particles to reheat the Universe adequately. Considering a class of $\alpha-$ attractor inflation models, we obtain the allowed mass ranges for RHN for both cases and thereafter furnish the estimates for $n_s$ and $r$. The prescription proposed here is general and can be implemented in various kinds of single-field inflationary models given the conditions for non-thermal leptogenesis are satisfied.
[ { "created": "Tue, 25 Oct 2022 17:12:22 GMT", "version": "v1" }, { "created": "Wed, 3 Jan 2024 18:41:56 GMT", "version": "v2" }, { "created": "Sat, 27 Jan 2024 16:20:00 GMT", "version": "v3" } ]
2024-04-25
[ [ "Ghoshal", "Anish", "" ], [ "Nanda", "Dibyendu", "" ], [ "Saha", "Abhijit Kumar", "" ] ]
We study the imprints of high scale non-thermal leptogenesis on cosmic microwave background (CMB) from the measurements of inflationary spectral index ($n_s$) and tensor-to-scalar ratio ($r$), which otherwise is inaccessible to the conventional laboratory experiments. We argue that non-thermal production of baryon (lepton) asymmetry from subsequent decays of inflaton to heavy right-handed neutrinos (RHN) and RHN to SM leptons is sensitive to the reheating dynamics in the early Universe after the end of inflation. Such dependence provides detectable imprints on the $n_s-r$ plane which is well constrained by the Planck experiment. We investigate two separate cases, (I) inflaton decays to radiation dominantly and (II) inflaton decays to RHN dominantly which further decays to the SM particles to reheat the Universe adequately. Considering a class of $\alpha-$ attractor inflation models, we obtain the allowed mass ranges for RHN for both cases and thereafter furnish the estimates for $n_s$ and $r$. The prescription proposed here is general and can be implemented in various kinds of single-field inflationary models given the conditions for non-thermal leptogenesis are satisfied.
1407.4466
Joshua Berger
Yang Bai and Joshua Berger
Coloron-assisted Leptoquarks at the LHC
5 pages, 4 figures
null
10.1016/j.physletb.2015.04.046
SLAC-PUB-16027
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent searches for a first-generation leptoquark by the CMS collaboration have shown around 2.5 sigma deviations from Standard Model predictions in both the eejj and e nu jj channels. Furthermore, the eejj invariant mass distribution has another 2.8 sigma excess from the CMS right-handed W plus heavy neutrino search. We point out that additional leptoquark production from a heavy coloron decay can provide a good explanation for all three excesses. The coloron has a mass around 2.1 TeV and the leptoquark mass can vary from 550 GeV to 650 GeV. A key prediction of this model is an edge in the total m_T distribution of e nu jj events at around 2.1 TeV.
[ { "created": "Wed, 16 Jul 2014 20:00:25 GMT", "version": "v1" } ]
2015-05-20
[ [ "Bai", "Yang", "" ], [ "Berger", "Joshua", "" ] ]
Recent searches for a first-generation leptoquark by the CMS collaboration have shown around 2.5 sigma deviations from Standard Model predictions in both the eejj and e nu jj channels. Furthermore, the eejj invariant mass distribution has another 2.8 sigma excess from the CMS right-handed W plus heavy neutrino search. We point out that additional leptoquark production from a heavy coloron decay can provide a good explanation for all three excesses. The coloron has a mass around 2.1 TeV and the leptoquark mass can vary from 550 GeV to 650 GeV. A key prediction of this model is an edge in the total m_T distribution of e nu jj events at around 2.1 TeV.
hep-ph/9510409
Hans Eggers
H.C. Eggers (McGill and HEPHY Vienna), R. Tabti, C. Gale (McGill) and K. Haglin (Michigan State)
Dilepton bremsstrahlung from pion-pion scattering in a relativistic OBE model
REVTeX 3.0, 26 pages plus 15 figures in uuencoded PostScript
Phys.Rev.D53:4822-4837,1996
10.1103/PhysRevD.53.4822
McGill/95--14, HEPHY--PUB 620/95, MSUCL--974
hep-ph nucl-th
null
We have made a detailed and quantitative study of dilepton production via bremsstrahlung of a virtual photon during pion-pion collisions. Most calculations of electromagnetic radiation from strong interaction processes rely on the soft photon approximation (SPA). The conditions underlying this approximation are generally violated when dilepton spectra are calculated in terms of their invariant mass, so that an approach going beyond the SPA becomes necessary. Superseding previous derivations, we derive an exact formula for the bremsstrahlung cross section. The resulting formulation is compared to various forms based on the SPA, the two-particle phase space approximation and R\"uckl's formula using a relativistic One Boson Exchange (OBE) model. Within the OBE approach, we show that approximations to the bremsstrahlung dilepton cross sections often differ greatly from the exact result; discrepancies become greater both with rising temperature and with invariant mass. Integrated dilepton production rates are overestimated by R\"uckl-based approximations by factors 1.5--8.0. The largest discrepancies occur for the reaction $\pi^+\pi^+ \to \pi^+\pi^+\ell^+\ell^-$, where such approximations overestimate the exact rate by factors ranging from 2 to 30 for invariant masses between 10 and 500 MeV. Our findings, combined with recent estimates of the Landau-Pomeranchuk effect, indicate that bremsstrahlung dileptons rates in ultrarelativistic heavy ion collisions should be even more suppressed than had been thought before.
[ { "created": "Wed, 25 Oct 1995 19:38:17 GMT", "version": "v1" } ]
2010-01-15
[ [ "Eggers", "H. C.", "", "McGill and HEPHY Vienna" ], [ "Tabti", "R.", "", "McGill" ], [ "Gale", "C.", "", "McGill" ], [ "Haglin", "K.", "", "Michigan State" ] ]
We have made a detailed and quantitative study of dilepton production via bremsstrahlung of a virtual photon during pion-pion collisions. Most calculations of electromagnetic radiation from strong interaction processes rely on the soft photon approximation (SPA). The conditions underlying this approximation are generally violated when dilepton spectra are calculated in terms of their invariant mass, so that an approach going beyond the SPA becomes necessary. Superseding previous derivations, we derive an exact formula for the bremsstrahlung cross section. The resulting formulation is compared to various forms based on the SPA, the two-particle phase space approximation and R\"uckl's formula using a relativistic One Boson Exchange (OBE) model. Within the OBE approach, we show that approximations to the bremsstrahlung dilepton cross sections often differ greatly from the exact result; discrepancies become greater both with rising temperature and with invariant mass. Integrated dilepton production rates are overestimated by R\"uckl-based approximations by factors 1.5--8.0. The largest discrepancies occur for the reaction $\pi^+\pi^+ \to \pi^+\pi^+\ell^+\ell^-$, where such approximations overestimate the exact rate by factors ranging from 2 to 30 for invariant masses between 10 and 500 MeV. Our findings, combined with recent estimates of the Landau-Pomeranchuk effect, indicate that bremsstrahlung dileptons rates in ultrarelativistic heavy ion collisions should be even more suppressed than had been thought before.
hep-ph/0604016
Yi Liao
Yi Liao (Nankai Univ)
Active-sterile neutrino mixing in the absence of bare active neutrino mass
21 pages, no figures, 2 tables; v2: added the last two refs in item [17], to appear in NPB
Nucl.Phys. B749 (2006) 153-171
10.1016/j.nuclphysb.2006.05.014
NKHEP 07/2006
hep-ph
null
We investigate a minimal extension of the standard model in which the only new ingredient is the sterile neutrinos. We do not introduce extra Higgs multiplets or high dimensional effective operators to induce mass terms for the active neutrinos, and the model is renormalizable in itself. We show for arbitrary numbers of generations and sterile neutrinos that the independent physical parameters in the leptonic sector are much less than previously anticipated. For instance, with three active and two sterile neutrinos, there are four mixing angles and three CP phases in addition to four non-vanishing neutrino masses. We study phenomenological implications for tritium beta decay, neutrinoless double beta decay and neutrino oscillations. For the most natural see-saw parameters, we find that it is difficult to accommodate in the model the best-fit values of masses and mixing parameters from oscillation data no matter whether we include or not the null short-baseline experiments together with the LSND result. This implies that if the LSND result is confirmed by MiniBooNE, the see-saw parameter region of the model with two sterile neutrinos could be largely excluded.
[ { "created": "Mon, 3 Apr 2006 14:01:52 GMT", "version": "v1" }, { "created": "Thu, 18 May 2006 00:04:34 GMT", "version": "v2" } ]
2009-11-11
[ [ "Liao", "Yi", "", "Nankai Univ" ] ]
We investigate a minimal extension of the standard model in which the only new ingredient is the sterile neutrinos. We do not introduce extra Higgs multiplets or high dimensional effective operators to induce mass terms for the active neutrinos, and the model is renormalizable in itself. We show for arbitrary numbers of generations and sterile neutrinos that the independent physical parameters in the leptonic sector are much less than previously anticipated. For instance, with three active and two sterile neutrinos, there are four mixing angles and three CP phases in addition to four non-vanishing neutrino masses. We study phenomenological implications for tritium beta decay, neutrinoless double beta decay and neutrino oscillations. For the most natural see-saw parameters, we find that it is difficult to accommodate in the model the best-fit values of masses and mixing parameters from oscillation data no matter whether we include or not the null short-baseline experiments together with the LSND result. This implies that if the LSND result is confirmed by MiniBooNE, the see-saw parameter region of the model with two sterile neutrinos could be largely excluded.
1003.0231
Taekoon Lee
Taekoon Lee
Renormalon Subtraction from the Average Plaquette and the Gluon Condensate
7pages,one figure; Journal version (added references and introductory remarks)
Phys.Rev.D82:114021,2010
10.1103/PhysRevD.82.114021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Borel resummation scheme of subtracting the perturbative contribution from the average plaquette is proposed using the bilocal expansion of Borel transform. It is shown that the remnant of the average plaquette, after subtraction of the perturbative contribution, scales as a dim-4 condensate. A critical review of the existing procedure of renormalon subtraction is presented.
[ { "created": "Mon, 1 Mar 2010 00:47:04 GMT", "version": "v1" }, { "created": "Mon, 3 Jan 2011 02:52:17 GMT", "version": "v2" } ]
2011-01-17
[ [ "Lee", "Taekoon", "" ] ]
A Borel resummation scheme of subtracting the perturbative contribution from the average plaquette is proposed using the bilocal expansion of Borel transform. It is shown that the remnant of the average plaquette, after subtraction of the perturbative contribution, scales as a dim-4 condensate. A critical review of the existing procedure of renormalon subtraction is presented.
hep-ph/0111184
Jong-Phil Lee
Jong-Phil Lee (Yonsei Univ.)
CP violating transverse lepton polarizaion in $B\to D^{(*)}\ell\bar\nu$ including tensor interactions
17 pages, figures and references are added, to appear in Phys. Lett. B
Phys.Lett. B526 (2002) 61-71
10.1016/S0370-2693(01)01492-7
null
hep-ph
null
We give a model-independent analysis of CP violating lepton polarization in the exclusive semileptonic B decay of $B\to D^{(*)}\ell\bar\nu$ including dimension six four-fermion tensor interactions at the heavy quark limit. It is shown that the tensor interactions should not be neglected if the associated couplings are comparable to others. The effect of tensor interactions on the transverse lepton polarization appears more dramatically in $B\to D$ than in $B\to D^*$. In the leptoquark model, the average transverse lepton polarization is estimated to be $|\bar{P^\perp_D}|\simeq 0.26$ and $|\bar{P^\perp_{D^*}}|\simeq 0.076$ with commonly used model parameters.
[ { "created": "Thu, 15 Nov 2001 08:07:31 GMT", "version": "v1" }, { "created": "Wed, 21 Nov 2001 06:00:14 GMT", "version": "v2" }, { "created": "Wed, 19 Dec 2001 05:42:13 GMT", "version": "v3" } ]
2009-11-07
[ [ "Lee", "Jong-Phil", "", "Yonsei Univ." ] ]
We give a model-independent analysis of CP violating lepton polarization in the exclusive semileptonic B decay of $B\to D^{(*)}\ell\bar\nu$ including dimension six four-fermion tensor interactions at the heavy quark limit. It is shown that the tensor interactions should not be neglected if the associated couplings are comparable to others. The effect of tensor interactions on the transverse lepton polarization appears more dramatically in $B\to D$ than in $B\to D^*$. In the leptoquark model, the average transverse lepton polarization is estimated to be $|\bar{P^\perp_D}|\simeq 0.26$ and $|\bar{P^\perp_{D^*}}|\simeq 0.076$ with commonly used model parameters.
0907.3963
Felix Yu
Mu-Chun Chen, K.T. Mahanthappa, Felix Yu
A Viable Randall-Sundrum Model for Quarks and Leptons with T' Family Symmetry
22 pages, no figures; v2: references added; version to appear in Phys. Rev. D
Phys.Rev.D81:036004,2010
10.1103/PhysRevD.81.036004
COLO-HEP-550, UCI-TR-2009-12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a Randall-Sundrum model with a bulk family symmetry based on the double tetrahedral group, T', which generates the tri-bimaximal neutrino mixing pattern and a realistic CKM matrix, including CP violation. Unlike 4D models where the generation of mass hierarchy requires additional symmetry, the warped geometry naturally gives rise to the fermion mass hierarchy through wavefunction localization. The T' symmetry forbids tree-level flavor changing neutral currents in both the quark and lepton sectors, as different generations of fermions are unified into multiplets of T'. This results in a low first KK mass scale and thus the model can be tested at collider experiments.
[ { "created": "Thu, 23 Jul 2009 00:23:13 GMT", "version": "v1" }, { "created": "Wed, 27 Jan 2010 04:52:29 GMT", "version": "v2" } ]
2014-11-20
[ [ "Chen", "Mu-Chun", "" ], [ "Mahanthappa", "K. T.", "" ], [ "Yu", "Felix", "" ] ]
We propose a Randall-Sundrum model with a bulk family symmetry based on the double tetrahedral group, T', which generates the tri-bimaximal neutrino mixing pattern and a realistic CKM matrix, including CP violation. Unlike 4D models where the generation of mass hierarchy requires additional symmetry, the warped geometry naturally gives rise to the fermion mass hierarchy through wavefunction localization. The T' symmetry forbids tree-level flavor changing neutral currents in both the quark and lepton sectors, as different generations of fermions are unified into multiplets of T'. This results in a low first KK mass scale and thus the model can be tested at collider experiments.
0803.1022
Alexander Monin
A. K. Monin, A. V. Zayakin
Semiclassical Treatment of Induced Schwinger Processes at Finite Temperature
10 pages, 1 fugure
JETP Lett.87:709-714,2008
10.1134/S0021364008110040
ITEP-TH-07/08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider induced pair production in an external field at finite temperature. One-loop correction to the Green function of a meson is calculated semiclassically within the framework of saddle-point analysis of Schwinger proper time integrals. This correction appears to be exponentially small in terms of inverse temperature dependence. Low-temperature limit is shown to be in full agreement with previously obtained zero-temperature results. The corrections in the low-temperature limits are estimated up to the leading exponential and pre-exponential terms. Comparison is made to earlier calculations of vacuum decay.
[ { "created": "Fri, 7 Mar 2008 18:56:28 GMT", "version": "v1" }, { "created": "Fri, 14 Mar 2008 17:19:43 GMT", "version": "v2" } ]
2009-02-19
[ [ "Monin", "A. K.", "" ], [ "Zayakin", "A. V.", "" ] ]
We consider induced pair production in an external field at finite temperature. One-loop correction to the Green function of a meson is calculated semiclassically within the framework of saddle-point analysis of Schwinger proper time integrals. This correction appears to be exponentially small in terms of inverse temperature dependence. Low-temperature limit is shown to be in full agreement with previously obtained zero-temperature results. The corrections in the low-temperature limits are estimated up to the leading exponential and pre-exponential terms. Comparison is made to earlier calculations of vacuum decay.
hep-ph/0008038
Marty Stock
R.L. Jaffe
The Theory of the Nucleon Spin
15 pages, 8 figures, LaTeX using rspublic.cls and BoxedEPS macros; as submitted to Phil Trans A of the Royal Society for forthcoming volume: The Quark Structure of Matter; email correspondence to jaffe@mit.edu
Phil.Trans.Roy.Soc.Lond. A359 (2001) 391-404
10.1098/rsta.2000.0731
MIT-CTP-3011
hep-ph
null
I discuss two topics of current interest in the study of the spin structure of the nucleon. First, I discuss whether there is a sum rule for the components of the nucleon's angular moments. Second, I discuss the measurement of the nucleon's transversity distribution in light of recent results reported by the HERMES collaboration at DESY.
[ { "created": "Thu, 3 Aug 2000 22:37:56 GMT", "version": "v1" } ]
2009-10-31
[ [ "Jaffe", "R. L.", "" ] ]
I discuss two topics of current interest in the study of the spin structure of the nucleon. First, I discuss whether there is a sum rule for the components of the nucleon's angular moments. Second, I discuss the measurement of the nucleon's transversity distribution in light of recent results reported by the HERMES collaboration at DESY.
1209.3622
Ken Mimasu
L. Basso, K. Mimasu, S.Moretti
Distinguishing Z' models with polarised top pairs
Proceedings submission for parallel talk given at `Rencontres de Blois' conference, France, June 2012. 5 pages, 1 figure
null
null
preprint SHEP-12-24; FR-PHENO-2012-025
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the sensitivity of top pair production at the Large Hadron Collider (LHC) to the nature of an underlying Z' boson, including full tree level standard model background effects and interferences. We demonstrate that exploiting combinations of asymmetry observables will enable one to distinguish between a selection of `benchmark' Z' models while assuming realistic final state reconstruction efficiencies and error estimates.
[ { "created": "Mon, 17 Sep 2012 10:39:31 GMT", "version": "v1" } ]
2012-11-26
[ [ "Basso", "L.", "" ], [ "Mimasu", "K.", "" ], [ "Moretti", "S.", "" ] ]
We study the sensitivity of top pair production at the Large Hadron Collider (LHC) to the nature of an underlying Z' boson, including full tree level standard model background effects and interferences. We demonstrate that exploiting combinations of asymmetry observables will enable one to distinguish between a selection of `benchmark' Z' models while assuming realistic final state reconstruction efficiencies and error estimates.
2301.08615
En Wang
Yun-He Lyu, Han Zhang, Neng-Chang Wei, Bai-Cian Ke, En Wang, and Ju-Jun Xie
Photo-production of lowest $\Sigma^*_{1/2^-}$ state within the Regge-effective Lagrangian approach
7 pages, 4 figures
null
10.1088/1674-1137/acc4ab
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Since the lowest $\Sigma^{*}$ state, with quantum numbers spin-parity $J^{P} =1/2^{-}$, is far from established experimentally and theoretically, we have performed a theoretical study on the $\Sigma^*_{1/2^-}$ photo-production within the Regge-effective Lagrangian approach. Taking into account that the $\Sigma^*_{1/2^-}$ couples to the $\bar{K}N$ channel, we have considered the contributions from the $t$-channel $K$ exchange diagram. Moreover, these contributions from $t$-channel $K^*$ exchange, $s$-channel nucleon pole, $u$-channel $\Sigma$ exchange, and the contact term, are considered. The differential and total cross sections of the process $\gamma n \to K^{+}\Sigma^{*-}_{1/2^-}$ are predicted with our model parameters. The results should be helpful to search for the $\Sigma^*_{1/2^-}$ state experimentally in future.
[ { "created": "Fri, 20 Jan 2023 14:55:55 GMT", "version": "v1" } ]
2023-04-26
[ [ "Lyu", "Yun-He", "" ], [ "Zhang", "Han", "" ], [ "Wei", "Neng-Chang", "" ], [ "Ke", "Bai-Cian", "" ], [ "Wang", "En", "" ], [ "Xie", "Ju-Jun", "" ] ]
Since the lowest $\Sigma^{*}$ state, with quantum numbers spin-parity $J^{P} =1/2^{-}$, is far from established experimentally and theoretically, we have performed a theoretical study on the $\Sigma^*_{1/2^-}$ photo-production within the Regge-effective Lagrangian approach. Taking into account that the $\Sigma^*_{1/2^-}$ couples to the $\bar{K}N$ channel, we have considered the contributions from the $t$-channel $K$ exchange diagram. Moreover, these contributions from $t$-channel $K^*$ exchange, $s$-channel nucleon pole, $u$-channel $\Sigma$ exchange, and the contact term, are considered. The differential and total cross sections of the process $\gamma n \to K^{+}\Sigma^{*-}_{1/2^-}$ are predicted with our model parameters. The results should be helpful to search for the $\Sigma^*_{1/2^-}$ state experimentally in future.
1808.03985
Fanrong Xu
Wei Li, Jiajie Ling, Fanrong Xu, Baobiao Yue
Matter Effect of Light Sterile Neutrino: An Exact Analytical Approach
17 pages, 8 figures for V1; typos are corrected, accepted by JHEP for V2
null
10.1007/JHEP10(2018)021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The light sterile neutrino, if it exists, will give additional contribution to matter effect when active neutrinos propagate through terrestrial matter. In the simplest 3+1 scheme, three more rotation angles and two more CP-violating phases in lepton mixing matrix make the interaction complicated formally. In this work, the exact analytical expressions for active neutrino oscillation probabilities in terrestrial matter, including sterile neutrino contribution, are derived. It is pointed out that this set of formulas contain information both in matter and in vacuum, and can be easily tuned by choosing related parameters. Based on the generic exact formulas, we present oscillation probabilities of typic medium and long baseline experiments. Taking NO$\nu$A experiment as an example, we show that in particular parameter space sterile neutrino gives important contribution to terrestrial matter effect, and Dirac phases play a vital role.
[ { "created": "Sun, 12 Aug 2018 18:55:17 GMT", "version": "v1" }, { "created": "Wed, 3 Oct 2018 07:14:11 GMT", "version": "v2" } ]
2018-10-17
[ [ "Li", "Wei", "" ], [ "Ling", "Jiajie", "" ], [ "Xu", "Fanrong", "" ], [ "Yue", "Baobiao", "" ] ]
The light sterile neutrino, if it exists, will give additional contribution to matter effect when active neutrinos propagate through terrestrial matter. In the simplest 3+1 scheme, three more rotation angles and two more CP-violating phases in lepton mixing matrix make the interaction complicated formally. In this work, the exact analytical expressions for active neutrino oscillation probabilities in terrestrial matter, including sterile neutrino contribution, are derived. It is pointed out that this set of formulas contain information both in matter and in vacuum, and can be easily tuned by choosing related parameters. Based on the generic exact formulas, we present oscillation probabilities of typic medium and long baseline experiments. Taking NO$\nu$A experiment as an example, we show that in particular parameter space sterile neutrino gives important contribution to terrestrial matter effect, and Dirac phases play a vital role.
1306.2956
Sven Bjarke Gudnason
Latif Eliaz, Amit Giveon, Sven Bjarke Gudnason, Eitan Tsuk
Mild-split SUSY with flavor
LaTeX, 37 pages, 15 figures; V2: references added, minor corrections in sec. 6
JHEP 1310:136,2013
10.1007/JHEP10(2013)136
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of a gauge mediated quiver-like model, the standard model flavor texture can be naturally generated. The model - like the MSSM - has furthermore a region in parameter space where the lightest Higgs mass is fed by heavy stop loops, which in turn sets the average squark mass scale near 10-20 TeV. We perform a careful flavor analysis to check whether this type of mild-split SUSY passes all flavor constraints as easily as envisioned in the original type of split SUSY. Interestingly, it turns out to be on the border of several constraints, in particular, the branching ratio of mu -> e gamma and, if order one complex phases are assumed, also epsilon_K neutron and electron EDM. Furthermore, we consider unification as well as dark matter candidates, especially the gravitino. Finally, we provide a closed-form formula for the soft masses of matter in arbitrary representations of any of the gauge groups in a generic quiver-like model with a general messenger sector.
[ { "created": "Wed, 12 Jun 2013 20:00:15 GMT", "version": "v1" }, { "created": "Sun, 20 Oct 2013 15:18:34 GMT", "version": "v2" } ]
2013-11-05
[ [ "Eliaz", "Latif", "" ], [ "Giveon", "Amit", "" ], [ "Gudnason", "Sven Bjarke", "" ], [ "Tsuk", "Eitan", "" ] ]
In the framework of a gauge mediated quiver-like model, the standard model flavor texture can be naturally generated. The model - like the MSSM - has furthermore a region in parameter space where the lightest Higgs mass is fed by heavy stop loops, which in turn sets the average squark mass scale near 10-20 TeV. We perform a careful flavor analysis to check whether this type of mild-split SUSY passes all flavor constraints as easily as envisioned in the original type of split SUSY. Interestingly, it turns out to be on the border of several constraints, in particular, the branching ratio of mu -> e gamma and, if order one complex phases are assumed, also epsilon_K neutron and electron EDM. Furthermore, we consider unification as well as dark matter candidates, especially the gravitino. Finally, we provide a closed-form formula for the soft masses of matter in arbitrary representations of any of the gauge groups in a generic quiver-like model with a general messenger sector.
hep-ph/0002125
Kari Enqvist
Kari Enqvist
Recent progress in Affleck-Dine baryogenesis
8 pages, 2 figures; invited talk at COSMO99
null
10.1142/9789812792129_0059
HIP-2000-09/TH
hep-ph
null
In the MSSM, cosmological scalar field condensates formed along flat directions of the scalar potential (Affleck-Dine condensates) are typically unstable with respect to formation of Q-balls, a type of non-topological soliton. I discuss the creation and growth of the quantum seed fluctuations which catalyse the collapse of the condensate. In D-term inflation models, the fluctuations of squark fields in the flat directions also give rise to isocurvature density fluctuations stored in the Affleck-Dine condensate. After the condensate breaks up, these can be perturbations in the baryon number, or, in the case where the present neutralino density comes directly from B-ball decay, perturbations in the number of dark matter neutralinos. The latter case results in a large enhancement of the isocurvature perturbation, which should be observable by PLANCK.
[ { "created": "Fri, 11 Feb 2000 07:49:02 GMT", "version": "v1" } ]
2016-11-03
[ [ "Enqvist", "Kari", "" ] ]
In the MSSM, cosmological scalar field condensates formed along flat directions of the scalar potential (Affleck-Dine condensates) are typically unstable with respect to formation of Q-balls, a type of non-topological soliton. I discuss the creation and growth of the quantum seed fluctuations which catalyse the collapse of the condensate. In D-term inflation models, the fluctuations of squark fields in the flat directions also give rise to isocurvature density fluctuations stored in the Affleck-Dine condensate. After the condensate breaks up, these can be perturbations in the baryon number, or, in the case where the present neutralino density comes directly from B-ball decay, perturbations in the number of dark matter neutralinos. The latter case results in a large enhancement of the isocurvature perturbation, which should be observable by PLANCK.
1602.07691
Krzysztof Rolbiecki
F. Domingo, S. Heinemeyer, J.S. Kim, K. Rolbiecki
The NMSSM lives: with the 750 GeV diphoton excess
24 pages, 4 figures; minor text improvements; to appear in EPJC
null
10.1140/epjc/s10052-016-4080-2
IFT-UAM/CSIC-16-019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an NMSSM scenario that can explain the excess in the diphoton spectrum at 750 GeV recently observed by ATLAS and CMS. We show that in a certain limit with a very light pseudoscalar one can reproduce the experimental results without invoking exotic matter. The 750 GeV excess is produced by two resonant heavy Higgs bosons with masses ~750 GeV, that subsequently decay to two light pseudoscalars. Each of these decays to collimated photon pairs that appear as a single photon in the electromagnetic calorimeter. A mass gap between heavy Higgses mimics a large width of the 750 GeV peak. The production mechanism, containing a strong component via initial b quarks, ameliorates a possible tension with 8 TeV data compared to other production modes. We also discuss other constraints, in particular from low energy experiments. Finally, we discuss possible methods that could distinguish our proposal from other physics models describing the diphoton excess in the Run-II of the LHC.
[ { "created": "Wed, 24 Feb 2016 21:00:04 GMT", "version": "v1" }, { "created": "Tue, 26 Apr 2016 09:27:37 GMT", "version": "v2" } ]
2016-05-25
[ [ "Domingo", "F.", "" ], [ "Heinemeyer", "S.", "" ], [ "Kim", "J. S.", "" ], [ "Rolbiecki", "K.", "" ] ]
We propose an NMSSM scenario that can explain the excess in the diphoton spectrum at 750 GeV recently observed by ATLAS and CMS. We show that in a certain limit with a very light pseudoscalar one can reproduce the experimental results without invoking exotic matter. The 750 GeV excess is produced by two resonant heavy Higgs bosons with masses ~750 GeV, that subsequently decay to two light pseudoscalars. Each of these decays to collimated photon pairs that appear as a single photon in the electromagnetic calorimeter. A mass gap between heavy Higgses mimics a large width of the 750 GeV peak. The production mechanism, containing a strong component via initial b quarks, ameliorates a possible tension with 8 TeV data compared to other production modes. We also discuss other constraints, in particular from low energy experiments. Finally, we discuss possible methods that could distinguish our proposal from other physics models describing the diphoton excess in the Run-II of the LHC.
2003.08320
Carlos Alberto Vaquera-Araujo
Ailier Rivero-Acosta and Carlos A. Vaquera-Araujo
Renormalization of a model for spin-1 matter fields
15 pages, 9 figures
null
10.1140/epjc/s10052-020-8190-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, the one-loop renormalization of a theory for fields transforming in the $(1,0)\oplus(0,1)$ representation of the Homogeneous Lorentz Group is studied. The model includes an arbitrary gyromagnetic factor and self-interactions of the spin 1 field, which has mass dimension one. The model is shown to be renormalizable for any value of the gyromagnetic factor.
[ { "created": "Wed, 18 Mar 2020 16:21:47 GMT", "version": "v1" }, { "created": "Tue, 14 Jul 2020 16:10:37 GMT", "version": "v2" } ]
2020-07-15
[ [ "Rivero-Acosta", "Ailier", "" ], [ "Vaquera-Araujo", "Carlos A.", "" ] ]
In this work, the one-loop renormalization of a theory for fields transforming in the $(1,0)\oplus(0,1)$ representation of the Homogeneous Lorentz Group is studied. The model includes an arbitrary gyromagnetic factor and self-interactions of the spin 1 field, which has mass dimension one. The model is shown to be renormalizable for any value of the gyromagnetic factor.
1605.07584
Ismail Zahed
Yizhuang Liu, Edward Shuryak and Ismail Zahed
Light Adjoint Quarks in the Instanton-Dyon Liquid Model IV
22 pages, 6 figures
Phys. Rev. D 94, 105012 (2016)
10.1103/PhysRevD.94.105012
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the instanton-dyon liquid model with $N_f$ Majorana quark flavors in the adjoint representation of color $SU_c(2)$ at finite temperature. We briefly recall the index theorem on $S^1\times R^3$ for twisted adjoint fermions in a BPS dyon background of arbitrary holonomy, and use the ADHM construction to explicit the adjoint anti-periodic zero modes. We use these results to derive the partition function of an interacting instanton-dyon ensemble with $N_f$ light and anti-periodic adjoint quarks. We develop the model in details by mapping the theory on a 3-dimensional quantum effective theory with adjoint quarks with manifest $SU(N_f)\times Z_{4N_f}$ symmetry. Using a mean-field analysis at weak coupling and strong screening, we show that center symmetry requires the spontaneous breaking of chiral symmetry, which is shown to only take place for $N_f=1$. For a sufficiently dense liquid, we find that the ground state is center symmetric and breaks spontaneously flavor symmetry through $SU(N_f)\times Z_{4N_f}\rightarrow O(N_f)$. As the liquid dilutes with increasing temperature, center symmetry and chiral symmetry are restored. We present numerical and analytical estimates for the transition temperatures.
[ { "created": "Tue, 24 May 2016 18:58:42 GMT", "version": "v1" } ]
2016-11-23
[ [ "Liu", "Yizhuang", "" ], [ "Shuryak", "Edward", "" ], [ "Zahed", "Ismail", "" ] ]
We discuss the instanton-dyon liquid model with $N_f$ Majorana quark flavors in the adjoint representation of color $SU_c(2)$ at finite temperature. We briefly recall the index theorem on $S^1\times R^3$ for twisted adjoint fermions in a BPS dyon background of arbitrary holonomy, and use the ADHM construction to explicit the adjoint anti-periodic zero modes. We use these results to derive the partition function of an interacting instanton-dyon ensemble with $N_f$ light and anti-periodic adjoint quarks. We develop the model in details by mapping the theory on a 3-dimensional quantum effective theory with adjoint quarks with manifest $SU(N_f)\times Z_{4N_f}$ symmetry. Using a mean-field analysis at weak coupling and strong screening, we show that center symmetry requires the spontaneous breaking of chiral symmetry, which is shown to only take place for $N_f=1$. For a sufficiently dense liquid, we find that the ground state is center symmetric and breaks spontaneously flavor symmetry through $SU(N_f)\times Z_{4N_f}\rightarrow O(N_f)$. As the liquid dilutes with increasing temperature, center symmetry and chiral symmetry are restored. We present numerical and analytical estimates for the transition temperatures.
1010.1204
Guy F. de T\'eramond
Guy F. de Teramond and Stanley J. Brodsky
Gauge/Gravity Duality and Strongly Coupled Light-Front Dynamics
Invited talk presented by GdT at Light Cone 2010: Relativistic Hadronic and Particle Physics, 14-18 June 2010, Valencia, Spain
PoS LC2010:029,2010
null
SLAC-PUB-14259
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We find a correspondence between semiclassical gauge theories quantized on the light-front and a dual gravity model in anti-de Sitter (AdS) space, thus providing an initial approximation to QCD in its strongly coupled regime. This correspondence -- light-front holography -- leads to a light-front Hamiltonian and relativistic bound-state wave equations in terms of an invariant impact variable $\zeta$ which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. Light-front holography also allows a precise mapping of transition amplitudes from AdS to physical space-time. In contrast with the usual AdS/QCD framework, the internal structure of hadrons is explicitly introduced in the gauge/gravity correspondence and the angular momentum of the constituents plays a key role. We also discuss how to introduce higher Fock-states in the correspondence as well as their relevance for describing the detailed structure of space and time-like form factors.
[ { "created": "Wed, 6 Oct 2010 16:59:15 GMT", "version": "v1" }, { "created": "Sun, 24 Oct 2010 13:56:43 GMT", "version": "v2" } ]
2011-03-10
[ [ "de Teramond", "Guy F.", "" ], [ "Brodsky", "Stanley J.", "" ] ]
We find a correspondence between semiclassical gauge theories quantized on the light-front and a dual gravity model in anti-de Sitter (AdS) space, thus providing an initial approximation to QCD in its strongly coupled regime. This correspondence -- light-front holography -- leads to a light-front Hamiltonian and relativistic bound-state wave equations in terms of an invariant impact variable $\zeta$ which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. Light-front holography also allows a precise mapping of transition amplitudes from AdS to physical space-time. In contrast with the usual AdS/QCD framework, the internal structure of hadrons is explicitly introduced in the gauge/gravity correspondence and the angular momentum of the constituents plays a key role. We also discuss how to introduce higher Fock-states in the correspondence as well as their relevance for describing the detailed structure of space and time-like form factors.
1106.4347
Richard F. Lebed
Richard F. Lebed and Van E. Mayes
Gauged Baryon and Lepton Number in MSSM_4 Brane Worlds
21 pages. Version accepted for publication in Phys. Rev. D
Phys.Rev. D 84: 075016, 2011
10.1103/PhysRevD.84.075016
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent D-brane model designed to accommodate a phenomenologically acceptable fourth generation of chiral fermions was noted to produce an unexpected additional unbroken nonanomalous U(1) gauge group at the string scale. We show that the corresponding charges acting on MSSM fields count baryon and lepton numbers. If broken spontaneously at lower scales, these U(1)_B and U(1)_L symmetries provide potential avenues for preserving baryogenesis while nonetheless explaining the suppression of proton decay (without the need for R parity), as well as the smallness of right-handed neutrino Majorana masses compared to the string scale.
[ { "created": "Tue, 21 Jun 2011 22:23:01 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2011 18:10:35 GMT", "version": "v2" }, { "created": "Tue, 25 Oct 2011 21:45:06 GMT", "version": "v3" } ]
2011-10-27
[ [ "Lebed", "Richard F.", "" ], [ "Mayes", "Van E.", "" ] ]
A recent D-brane model designed to accommodate a phenomenologically acceptable fourth generation of chiral fermions was noted to produce an unexpected additional unbroken nonanomalous U(1) gauge group at the string scale. We show that the corresponding charges acting on MSSM fields count baryon and lepton numbers. If broken spontaneously at lower scales, these U(1)_B and U(1)_L symmetries provide potential avenues for preserving baryogenesis while nonetheless explaining the suppression of proton decay (without the need for R parity), as well as the smallness of right-handed neutrino Majorana masses compared to the string scale.
1401.3029
John W. Moffat
J. W. Moffat
A Composite Model of Quarks and Bosons
9 pages, no figures
Int. J. Mod. Phys. A, 30, (2015) 1550014
10.1142/S0217751X15500141
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A composite model of quarks and bosons is proposed in which a spin $1/2$ isospin doublet $\psi$ is the basic building block of quarks and bosons in the standard model. The $\psi$ has two components $v$ and $w$ with charges $Q=\frac{1}{3}e$ and $Q=0$, respectively, that combine to form the three generations of colored quark flavors. A strong force described by a triplet of massless gluons bind the constituents called geminis. The confining constituent non-Abelian $SU(2)_C$ field theory is called constituent dynamics with a confining energy scale $\Lambda_{CD}$. The constituent dynamics condensate $\langle\bar{v}v+\bar{w}w\rangle\neq 0$ spontaneously breaks the electroweak symmetry $SU(2)_L\times U(1)_Y\rightarrow U(1)_{\rm EM}$ and a triplet of Nambu-Goldstone bosons make the gauge bosons $W^{\pm}$ and $Z^0$ massive, while retaining a massless photon. A global custodial $SU(2)_L\times SU(2)_R$ symmetry guarantees that the symmetry breaking in the weak interaction sector agrees with electroweak data. The non-Abelian $SU(2)_C$ color dynamics satisfies asymptotic freedom, which resolves the gauge and Higgs mass hierarchy problems and makes the model ultraviolet complete. The composite constituent dynamics model can realize a $SU(3)_C\times SU(2)_L\times U(1)_Y$ electroweak and strong interaction model that satisfies the naturalness principle. The three generations of colorless quarks $\alpha$ and $\beta$ with charges $Q=+1e$ and $Q=0$, respectively, which are predicted to exist in the composite model can form bound states which can be identified with the spectrum of exotic mesons.
[ { "created": "Mon, 13 Jan 2014 22:31:22 GMT", "version": "v1" }, { "created": "Thu, 23 Jan 2014 21:36:44 GMT", "version": "v2" } ]
2015-02-05
[ [ "Moffat", "J. W.", "" ] ]
A composite model of quarks and bosons is proposed in which a spin $1/2$ isospin doublet $\psi$ is the basic building block of quarks and bosons in the standard model. The $\psi$ has two components $v$ and $w$ with charges $Q=\frac{1}{3}e$ and $Q=0$, respectively, that combine to form the three generations of colored quark flavors. A strong force described by a triplet of massless gluons bind the constituents called geminis. The confining constituent non-Abelian $SU(2)_C$ field theory is called constituent dynamics with a confining energy scale $\Lambda_{CD}$. The constituent dynamics condensate $\langle\bar{v}v+\bar{w}w\rangle\neq 0$ spontaneously breaks the electroweak symmetry $SU(2)_L\times U(1)_Y\rightarrow U(1)_{\rm EM}$ and a triplet of Nambu-Goldstone bosons make the gauge bosons $W^{\pm}$ and $Z^0$ massive, while retaining a massless photon. A global custodial $SU(2)_L\times SU(2)_R$ symmetry guarantees that the symmetry breaking in the weak interaction sector agrees with electroweak data. The non-Abelian $SU(2)_C$ color dynamics satisfies asymptotic freedom, which resolves the gauge and Higgs mass hierarchy problems and makes the model ultraviolet complete. The composite constituent dynamics model can realize a $SU(3)_C\times SU(2)_L\times U(1)_Y$ electroweak and strong interaction model that satisfies the naturalness principle. The three generations of colorless quarks $\alpha$ and $\beta$ with charges $Q=+1e$ and $Q=0$, respectively, which are predicted to exist in the composite model can form bound states which can be identified with the spectrum of exotic mesons.
2104.12213
P. Divari C.
John D. Vergados, Paraskevi C. Divari, Hiroyasu Ejiri
Calculated event rates for Axion Detection via Atomic and Nuclear Processes
28 pages, 17 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The possibility of detection of 5.5 MeV and 14.4 keV solar axions by observing axion-induced nuclear and atomic transitions is investigated. The presence of nuclear transitions between spin-orbit partners can be manifested by the subsequent de-excitation via gamma ray emissions. The transition rates can also be studied in the context of radiative axion absorption by a nucleus. The elementary interaction is obtained in the context of the axion-quark couplings predicted by existing axion models. Then these couplings will be transformed to the nucleon level utilizing reasonable existing models, which lead to effective transition operators. Using these operators we calculate the needed nuclear matrix elements employing wave functions obtained in the context of the nuclear shell model. With these ingredients, we discuss possibilities of experimental observation of the axion-induced nuclear gamma-rays. In the second part, we will examine the axion-induced production of X-rays (axion-photon conversion) or ionization from deeply bound electron orbits. In this case, the axion electron coupling is predicted by existing axion models, no renormalization is needed. The experimental signal is the observation of directly produced electrons and/or the emission of hard X-rays and Auger electrons, following the de-excitation of the final atom. Critical discussion is made on the experimental feasibility of detecting the solar axions by using multi-ton scale NaI detectors.
[ { "created": "Sun, 25 Apr 2021 17:14:08 GMT", "version": "v1" }, { "created": "Sat, 8 May 2021 19:39:55 GMT", "version": "v2" }, { "created": "Fri, 10 Dec 2021 21:24:39 GMT", "version": "v3" } ]
2021-12-14
[ [ "Vergados", "John D.", "" ], [ "Divari", "Paraskevi C.", "" ], [ "Ejiri", "Hiroyasu", "" ] ]
The possibility of detection of 5.5 MeV and 14.4 keV solar axions by observing axion-induced nuclear and atomic transitions is investigated. The presence of nuclear transitions between spin-orbit partners can be manifested by the subsequent de-excitation via gamma ray emissions. The transition rates can also be studied in the context of radiative axion absorption by a nucleus. The elementary interaction is obtained in the context of the axion-quark couplings predicted by existing axion models. Then these couplings will be transformed to the nucleon level utilizing reasonable existing models, which lead to effective transition operators. Using these operators we calculate the needed nuclear matrix elements employing wave functions obtained in the context of the nuclear shell model. With these ingredients, we discuss possibilities of experimental observation of the axion-induced nuclear gamma-rays. In the second part, we will examine the axion-induced production of X-rays (axion-photon conversion) or ionization from deeply bound electron orbits. In this case, the axion electron coupling is predicted by existing axion models, no renormalization is needed. The experimental signal is the observation of directly produced electrons and/or the emission of hard X-rays and Auger electrons, following the de-excitation of the final atom. Critical discussion is made on the experimental feasibility of detecting the solar axions by using multi-ton scale NaI detectors.
1602.03653
Kyu Jung Bae
Kyu Jung Bae, Motoi Endo, Koichi Hamaguchi and Takeo Moroi
Diphoton Excess and Running Couplings
1+17 pages
null
10.1016/j.physletb.2016.04.031
UT-16-07, IPMU-16-0015
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recently observed diphoton excess at the LHC may suggest the existence of a singlet (pseudo-) scalar particle with a mass of 750 GeV which couples to gluons and photons. Assuming that the couplings to gluons and photons originate from loops of fermions and/or scalars charged under the Standard Model gauge groups, we show that here is a model-independent upper bound on the cross section $\sigma(pp\to S\to \gamma\gamma)$ as a function of the cutoff scale $\Lambda$ and masses of the fermions and scalars in the loop. Such a bound comes from the fact that the contribution of each particle to the diphoton event amplitude is proportional to its contribution to the one-loop $\beta$ functions of the gauge couplings. We also investigate the perturbativity of running Yukawa couplings in models with fermion loops, and show the upper bounds on $\sigma(pp\to S\to \gamma\gamma)$ for explicit models.
[ { "created": "Thu, 11 Feb 2016 09:41:28 GMT", "version": "v1" } ]
2016-05-04
[ [ "Bae", "Kyu Jung", "" ], [ "Endo", "Motoi", "" ], [ "Hamaguchi", "Koichi", "" ], [ "Moroi", "Takeo", "" ] ]
The recently observed diphoton excess at the LHC may suggest the existence of a singlet (pseudo-) scalar particle with a mass of 750 GeV which couples to gluons and photons. Assuming that the couplings to gluons and photons originate from loops of fermions and/or scalars charged under the Standard Model gauge groups, we show that here is a model-independent upper bound on the cross section $\sigma(pp\to S\to \gamma\gamma)$ as a function of the cutoff scale $\Lambda$ and masses of the fermions and scalars in the loop. Such a bound comes from the fact that the contribution of each particle to the diphoton event amplitude is proportional to its contribution to the one-loop $\beta$ functions of the gauge couplings. We also investigate the perturbativity of running Yukawa couplings in models with fermion loops, and show the upper bounds on $\sigma(pp\to S\to \gamma\gamma)$ for explicit models.
1504.00574
Konstantinos Alexandros Petridis
Ulrik Egede, Mitesh Patel, Konstantinos A. Petridis
Method for an unbinned measurement of the $q^2$ dependent decay amplitudes of $\bar{B}^{0}\to \bar{K}^{*0}\mu^+\mu^-$ decays
24 pages, 9 figures
JHEP 06 (2015) 084
10.1007/JHEP06(2015)084
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/3.0/
A method for determining the $q^2$ dependent $\bar{K}^{*0}$ spin amplitudes of $\bar{B}^{0}\to \bar{K}^{*0}\mu^+\mu^-$ decays through a maximum likelihood fit to data is presented. While current experimental techniques extract a limited set of observables in bins of $q^2$, our approach allows for the determination of all observable quantities as continuous distributions in $q^2$. By doing this, the method eliminates the need to correct theory predictions of these observables for $q^2$ averaging effects, thus increasing the sensitivity to the effects of physics beyond the Standard Model. Accounting for the symmetries of the angular distribution and using a three parameter ansatz for the $q^2$ dependence of the amplitudes, the precision of the angular observables and the sensitivity to new physics is estimated using simulated events. These studies are based on the sample sizes collected by the LHCb experiment during Run-I and expected for Run-II.
[ { "created": "Thu, 2 Apr 2015 14:42:41 GMT", "version": "v1" }, { "created": "Thu, 25 Jun 2015 17:19:26 GMT", "version": "v2" } ]
2015-06-26
[ [ "Egede", "Ulrik", "" ], [ "Patel", "Mitesh", "" ], [ "Petridis", "Konstantinos A.", "" ] ]
A method for determining the $q^2$ dependent $\bar{K}^{*0}$ spin amplitudes of $\bar{B}^{0}\to \bar{K}^{*0}\mu^+\mu^-$ decays through a maximum likelihood fit to data is presented. While current experimental techniques extract a limited set of observables in bins of $q^2$, our approach allows for the determination of all observable quantities as continuous distributions in $q^2$. By doing this, the method eliminates the need to correct theory predictions of these observables for $q^2$ averaging effects, thus increasing the sensitivity to the effects of physics beyond the Standard Model. Accounting for the symmetries of the angular distribution and using a three parameter ansatz for the $q^2$ dependence of the amplitudes, the precision of the angular observables and the sensitivity to new physics is estimated using simulated events. These studies are based on the sample sizes collected by the LHCb experiment during Run-I and expected for Run-II.
hep-ph/9311236
Edmond Iancu
Edmond Iancu
Soft Fields and Hard Particles in Hot Gauge Plasmas
Talk given at the 3rd Workshop on Thermal Field Theories and their Applications, Aug. 93, Banff, Canada; 7 pages; SACLAY-T93/122
null
null
null
hep-ph
null
It is shown that the long wavelength excitations of a quark-gluon plasma may be described as collective oscillations of self-consistent average fields to which the plasma particles couple. Their properties are obtained from a set of coupled mean field and kinetic equations, derived from the general Dyson-Schwinger equations, as the leading order in a systematic expansion in powers of the coupling. By solving the kinetic equations, one obtains in closed form the generating functionals for all the leading order amplitudes between soft quasiparticles, the so-called ``hard thermal loops''.
[ { "created": "Mon, 8 Nov 1993 03:46:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Iancu", "Edmond", "" ] ]
It is shown that the long wavelength excitations of a quark-gluon plasma may be described as collective oscillations of self-consistent average fields to which the plasma particles couple. Their properties are obtained from a set of coupled mean field and kinetic equations, derived from the general Dyson-Schwinger equations, as the leading order in a systematic expansion in powers of the coupling. By solving the kinetic equations, one obtains in closed form the generating functionals for all the leading order amplitudes between soft quasiparticles, the so-called ``hard thermal loops''.
2011.04821
Ke-Pan Xie
Ke-Pan Xie
Lepton-mediated electroweak baryogenesis, gravitational waves and the $4\tau$ final state at the collider
21 pages, 4 figures and 1 table. Formulae in the appendix corrected; main conclusions unchanged
null
10.1007/JHEP02(2021)090
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
An electroweak baryogenesis (EWBG) mechanism mediated by $\tau$ lepton transport is proposed. We extend the Standard Model with a real singlet scalar $S$ to trigger the strong first-order electroweak phase transition (SFOEWPT), and with a set of leptophilic dimension-5 operators to provide sufficient CP violating source. We demonstrate this model is able to generate the observed baryon asymmetry of the universe. This scenario is experimentally testable via either the SFOEWPT gravitational wave signals at the next-generation space-based detectors, or the $pp\to h^*\to SS\to 4\tau$ process (where $h^*$ is an off-shell Higgs) at the hadron colliders. A detailed collider simulation shows that a considerable fraction of parameter space can be probed at the HL-LHC, while almost the whole parameter space allowed by EWBG can be reached by the 27 TeV HE-LHC.
[ { "created": "Mon, 9 Nov 2020 23:16:31 GMT", "version": "v1" }, { "created": "Mon, 25 Jan 2021 23:22:00 GMT", "version": "v2" }, { "created": "Sat, 12 Jun 2021 04:52:50 GMT", "version": "v3" }, { "created": "Wed, 16 Jun 2021 23:48:35 GMT", "version": "v4" } ]
2021-06-18
[ [ "Xie", "Ke-Pan", "" ] ]
An electroweak baryogenesis (EWBG) mechanism mediated by $\tau$ lepton transport is proposed. We extend the Standard Model with a real singlet scalar $S$ to trigger the strong first-order electroweak phase transition (SFOEWPT), and with a set of leptophilic dimension-5 operators to provide sufficient CP violating source. We demonstrate this model is able to generate the observed baryon asymmetry of the universe. This scenario is experimentally testable via either the SFOEWPT gravitational wave signals at the next-generation space-based detectors, or the $pp\to h^*\to SS\to 4\tau$ process (where $h^*$ is an off-shell Higgs) at the hadron colliders. A detailed collider simulation shows that a considerable fraction of parameter space can be probed at the HL-LHC, while almost the whole parameter space allowed by EWBG can be reached by the 27 TeV HE-LHC.
1806.01712
Chul Kim
Junegone Chay, Chul Kim
Factorized groomed jet mass distribution in inclusive jet processes
31 pages, 8 figures
null
10.3938/jkps.74.439
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the factorized groomed jet mass distribution in inclusive jet processes using modified mass drop tagger (mMDT), corresponding to soft drop with the angular exponent $\beta =0$. A grooming procedure is implemented rather than tagging in the sense that grooming always returns a groomed jet, while tagging dose not return a jet when a single particle remains after tagging. We find that the grooming procedure makes the jet mass distribution infrared safe and only ultraviolet divergences appear in each factorized part. The groomed jet mass distributions are investigated in a wide range of the jet mass considering various limits on the jet mass variable $\rho = M_J^2/(p_T^JR)^2$ and the grooming cut $y_c$. Appropriate effective theories in different kinematic regions are employed to resum large logarithms, in which the analysis in the region $\rho \sim y_c \ll 1$ is included due to the different type of factorization. The analytic computation of the factorized groomed jet mass distribution is presented by resumming the large logarithms in the jet mass, and $y_c$. Numerically, the effect of the resummation is notably enhanced, compared with the calculation at next-to-leading order, and nonglobal logarithms are estimated to be small.
[ { "created": "Tue, 5 Jun 2018 14:25:10 GMT", "version": "v1" } ]
2019-03-27
[ [ "Chay", "Junegone", "" ], [ "Kim", "Chul", "" ] ]
We consider the factorized groomed jet mass distribution in inclusive jet processes using modified mass drop tagger (mMDT), corresponding to soft drop with the angular exponent $\beta =0$. A grooming procedure is implemented rather than tagging in the sense that grooming always returns a groomed jet, while tagging dose not return a jet when a single particle remains after tagging. We find that the grooming procedure makes the jet mass distribution infrared safe and only ultraviolet divergences appear in each factorized part. The groomed jet mass distributions are investigated in a wide range of the jet mass considering various limits on the jet mass variable $\rho = M_J^2/(p_T^JR)^2$ and the grooming cut $y_c$. Appropriate effective theories in different kinematic regions are employed to resum large logarithms, in which the analysis in the region $\rho \sim y_c \ll 1$ is included due to the different type of factorization. The analytic computation of the factorized groomed jet mass distribution is presented by resumming the large logarithms in the jet mass, and $y_c$. Numerically, the effect of the resummation is notably enhanced, compared with the calculation at next-to-leading order, and nonglobal logarithms are estimated to be small.
1205.6525
David McKeen
David McKeen, Maxim Pospelov
Testing Parity with Atomic Radiative Capture of $\mu^-$
To appear in PRL
Phys.Rev.Lett.108:263401,2012
10.1103/PhysRevLett.108.263401
null
hep-ph hep-ex nucl-ex nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The next generation of "intensity frontier" facilities will bring a significant increase in the intensity of sub-relativistic beams of $\mu^-$. We show that the use of these beams in combination with thin targets of $Z\sim 30$ elements opens up the possibility of testing parity-violating interactions of muons with nuclei via direct radiative capture of muons into atomic 2S orbitals. Since atomic capture preserves longitudinal muon polarization, the measurement of the gamma ray angular asymmetry in the single photon $2S_{1/2}$-$1S_{1/2}$ transition will offer a direct test of parity. We calculate the probability of atomic radiative capture taking into account the finite size of the nucleus to show that this process can dominate over the usual muonic atom cascade, and that the as yet unobserved single photon $2S_{1/2}$-$1S_{1/2}$ transition in muonic atoms can be detected in this way using current muon facilities.
[ { "created": "Wed, 30 May 2012 01:31:34 GMT", "version": "v1" } ]
2012-07-03
[ [ "McKeen", "David", "" ], [ "Pospelov", "Maxim", "" ] ]
The next generation of "intensity frontier" facilities will bring a significant increase in the intensity of sub-relativistic beams of $\mu^-$. We show that the use of these beams in combination with thin targets of $Z\sim 30$ elements opens up the possibility of testing parity-violating interactions of muons with nuclei via direct radiative capture of muons into atomic 2S orbitals. Since atomic capture preserves longitudinal muon polarization, the measurement of the gamma ray angular asymmetry in the single photon $2S_{1/2}$-$1S_{1/2}$ transition will offer a direct test of parity. We calculate the probability of atomic radiative capture taking into account the finite size of the nucleus to show that this process can dominate over the usual muonic atom cascade, and that the as yet unobserved single photon $2S_{1/2}$-$1S_{1/2}$ transition in muonic atoms can be detected in this way using current muon facilities.
1502.03725
Naoya Kitajima
Naoya Kitajima, Fuminobu Takahashi
Gravitational waves from Higgs domain walls
15 pages, 3 figures; v2: title changed, comments and references added; v3: accepted for publication in PLB
Phys.Lett. B745 (2015) 112-117
10.1016/j.physletb.2015.04.040
TU-991, IPMU15-0016
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effective potential for the Standard Model Higgs field allows two quasi-degenerate vacua; one is our vacuum at the electroweak scale, while the other is at a much higher scale. The latter minimum may be at a scale much smaller than the Planck scale, if the potential is lifted by new physics. This gives rise to a possibility of domain wall formation after inflation. If the high-scale minimum is a local minimum, domain walls are unstable and disappear through violent annihilation processes, producing a significant amount of gravitational waves. We estimate the amount of gravitational waves produced from unstable domain walls in the Higgs potential and discuss detectability with future experiments.
[ { "created": "Thu, 12 Feb 2015 16:45:14 GMT", "version": "v1" }, { "created": "Tue, 24 Feb 2015 07:12:34 GMT", "version": "v2" }, { "created": "Thu, 7 May 2015 08:27:07 GMT", "version": "v3" } ]
2015-05-08
[ [ "Kitajima", "Naoya", "" ], [ "Takahashi", "Fuminobu", "" ] ]
The effective potential for the Standard Model Higgs field allows two quasi-degenerate vacua; one is our vacuum at the electroweak scale, while the other is at a much higher scale. The latter minimum may be at a scale much smaller than the Planck scale, if the potential is lifted by new physics. This gives rise to a possibility of domain wall formation after inflation. If the high-scale minimum is a local minimum, domain walls are unstable and disappear through violent annihilation processes, producing a significant amount of gravitational waves. We estimate the amount of gravitational waves produced from unstable domain walls in the Higgs potential and discuss detectability with future experiments.
1302.0703
Juan Nieves Dr.
J. Nieves, I. Ruiz Simo and M.J. Vicente Vacas
Two Particle-Hole Excitations in Charged Current Quasielastic Antineutrino--Nucleus Scattering
6 pages, 4 figures
null
10.1016/j.physletb.2013.03.002
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the quasielastic and multinucleon contributions to the antineutrino nucleus scattering cross section and compare our results with the recent MiniBooNE data. We use a local Fermi gas model that includes RPA correlations and gets the multinucleon part from a systematic many body expansion of the $W$ boson selfenergy in the nuclear medium. The same model had been quite successful for the neutrino cross section and contains no new parameters. We have also analysed the relevance of 2p2h events for the antineutrino energy reconstruction.
[ { "created": "Mon, 4 Feb 2013 14:28:18 GMT", "version": "v1" } ]
2015-06-12
[ [ "Nieves", "J.", "" ], [ "Simo", "I. Ruiz", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
We evaluate the quasielastic and multinucleon contributions to the antineutrino nucleus scattering cross section and compare our results with the recent MiniBooNE data. We use a local Fermi gas model that includes RPA correlations and gets the multinucleon part from a systematic many body expansion of the $W$ boson selfenergy in the nuclear medium. The same model had been quite successful for the neutrino cross section and contains no new parameters. We have also analysed the relevance of 2p2h events for the antineutrino energy reconstruction.
1009.1878
Bin He
Bin He, Nobuchika Okada and Qaisar Shafi
Higgs Boson Mass Bounds in Seesaw Extended Standard Model with Non-Minimal Gravitational Coupling
16 pages, 8 figures; added references
Phys.Lett.B695:219-224,2011
10.1016/j.physletb.2010.11.020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the presence of non-minimal gravitational coupling $ \xi H^\dagger H {\cal R}$ between the standard model (SM) Higgs doublet $H$ and the curvature scalar ${\cal R}$, the effective ultraviolet cutoff scale is given by $\Lambda_{\rm cut}\approx m_P/\xi$, where $m_P$ is the reduced Planck mass, and $\xi \gtrsim 1$ is a dimensionless coupling constant. In type I and type III seesaw extended SM, which can naturally explain the observed solar and atmospheric neutrino oscillations, we investigate the implications of this non-minimal gravitational coupling for the SM Higgs boson mass bounds based on vacuum stability and perturbativity arguments. A lower bound on the Higgs boson mass close to 120 GeV is realized with type III seesaw and $\xi \sim 10-10^3$.
[ { "created": "Thu, 9 Sep 2010 20:10:51 GMT", "version": "v1" }, { "created": "Wed, 22 Sep 2010 21:23:06 GMT", "version": "v2" } ]
2011-05-12
[ [ "He", "Bin", "" ], [ "Okada", "Nobuchika", "" ], [ "Shafi", "Qaisar", "" ] ]
In the presence of non-minimal gravitational coupling $ \xi H^\dagger H {\cal R}$ between the standard model (SM) Higgs doublet $H$ and the curvature scalar ${\cal R}$, the effective ultraviolet cutoff scale is given by $\Lambda_{\rm cut}\approx m_P/\xi$, where $m_P$ is the reduced Planck mass, and $\xi \gtrsim 1$ is a dimensionless coupling constant. In type I and type III seesaw extended SM, which can naturally explain the observed solar and atmospheric neutrino oscillations, we investigate the implications of this non-minimal gravitational coupling for the SM Higgs boson mass bounds based on vacuum stability and perturbativity arguments. A lower bound on the Higgs boson mass close to 120 GeV is realized with type III seesaw and $\xi \sim 10-10^3$.
hep-ph/0009042
Olivier Leitner
X.-H. Guo, O. Leitner, A.W. Thomas
Enhanced Direct CP Violation in $B^{\pm} \to \rho^{0} \pi^{\pm}$
37 pages, 7 figures
Phys.Rev.D63:056012,2001
10.1103/PhysRevD.63.056012
ADP-00-44/T427, PCCF-RI-0018
hep-ph
null
We study direct CP violation in the hadronic decay $B^{\pm} \to \rho^{0}\pi^{\pm}$, including the effect of $\rho - \omega$ mixing. We find that the CP violating asymmetry is strongly dependent on the CKM matrix elements, especially the Wolfenstein parameter $\eta$. For fixed $N_{c}$ (the effective parameter associated with factorization), the CP violating asymmetry, $a$, has a maximum of order $30%-50%$ when the invariant mass of the $\pi^{+}\pi^{-}$ pair is in the vicinity of the $\omega$ resonance. The sensitivity of the asymmetry, $a$, to $N_{c}$ is small. Moreover, if $N_{c}$ is constrained using the latest experimental branching ratios from the CLEO collaboration, we find that the sign of $\sin \delta$ is always positive. Thus, a measurement of direct CP violation in $B^{\pm} \to \rho^{0}\pi^{\pm}$ would remove the mod$(\pi)$ ambiguity in ${\rm arg}[ - \frac{V_{td}V_{tb}^{\star}}{V_{ud}V_{ub}^{\star}}]$.
[ { "created": "Tue, 5 Sep 2000 00:19:01 GMT", "version": "v1" } ]
2010-02-17
[ [ "Guo", "X. -H.", "" ], [ "Leitner", "O.", "" ], [ "Thomas", "A. W.", "" ] ]
We study direct CP violation in the hadronic decay $B^{\pm} \to \rho^{0}\pi^{\pm}$, including the effect of $\rho - \omega$ mixing. We find that the CP violating asymmetry is strongly dependent on the CKM matrix elements, especially the Wolfenstein parameter $\eta$. For fixed $N_{c}$ (the effective parameter associated with factorization), the CP violating asymmetry, $a$, has a maximum of order $30%-50%$ when the invariant mass of the $\pi^{+}\pi^{-}$ pair is in the vicinity of the $\omega$ resonance. The sensitivity of the asymmetry, $a$, to $N_{c}$ is small. Moreover, if $N_{c}$ is constrained using the latest experimental branching ratios from the CLEO collaboration, we find that the sign of $\sin \delta$ is always positive. Thus, a measurement of direct CP violation in $B^{\pm} \to \rho^{0}\pi^{\pm}$ would remove the mod$(\pi)$ ambiguity in ${\rm arg}[ - \frac{V_{td}V_{tb}^{\star}}{V_{ud}V_{ub}^{\star}}]$.
2205.06669
Nico Benincasa
Nico Benincasa, Luigi Delle Rose, Kristjan Kannike, Luca Marzola
Multi-step phase transitions and gravitational waves in the inert doublet model
27 pages, 17 figures. Version accepted by JCAP
null
10.1088/1475-7516/2022/12/025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inert doublet model is a well-motivated extension of the Standard Model that contains a dark matter candidate and modifies the dynamics of the electroweak symmetry breaking. In order to detail its phenomenology, we perform a comprehensive study of cosmic phase transitions and gravitational wave signals implied by the framework, accounting for the latest results of collider experiments. We require the neutral inert scalar to constitute, at least, a subdominant part of the observed dark matter abundance. While most of the phase transitions proceed through a single step, we identify regions of the parameter space where the electroweak vacuum is reached after multiple phase transitions. The resulting gravitational wave spectrum is generally dominated by single-step transitions and, in part of the parameter space, falls within the reach of future gravitational wave detectors such as LISA, BBO or DECIGO. We find that direct detection experiments efficiently probe the part of parameter space associated with multi-step phase transitions, which remain unconstrained only in the Higgs resonance region testable with future monojet searches. The implications of the new determination of the $W$ boson mass are also discussed.
[ { "created": "Fri, 13 May 2022 14:20:14 GMT", "version": "v1" }, { "created": "Thu, 15 Dec 2022 13:21:12 GMT", "version": "v2" } ]
2022-12-28
[ [ "Benincasa", "Nico", "" ], [ "Rose", "Luigi Delle", "" ], [ "Kannike", "Kristjan", "" ], [ "Marzola", "Luca", "" ] ]
The inert doublet model is a well-motivated extension of the Standard Model that contains a dark matter candidate and modifies the dynamics of the electroweak symmetry breaking. In order to detail its phenomenology, we perform a comprehensive study of cosmic phase transitions and gravitational wave signals implied by the framework, accounting for the latest results of collider experiments. We require the neutral inert scalar to constitute, at least, a subdominant part of the observed dark matter abundance. While most of the phase transitions proceed through a single step, we identify regions of the parameter space where the electroweak vacuum is reached after multiple phase transitions. The resulting gravitational wave spectrum is generally dominated by single-step transitions and, in part of the parameter space, falls within the reach of future gravitational wave detectors such as LISA, BBO or DECIGO. We find that direct detection experiments efficiently probe the part of parameter space associated with multi-step phase transitions, which remain unconstrained only in the Higgs resonance region testable with future monojet searches. The implications of the new determination of the $W$ boson mass are also discussed.
1705.05358
Chang-Hun Lee
Chang-Hun Lee
Construction of lepton mass matrices and TeV-scale phenomenology in the minimal left-right symmetric model
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a systematic procedure of constructing lepton mass matrices that satisfy all the experimental constraints in the light lepton sector of the minimal left-right symmetric model with type-I seesaw dominance. This method is unique since it is applicable to the most general cases of type-I seesaw with complex electroweak vacuum expectation values in the model. With this method, we investigate the TeV-scale phenomenology in the normal hierarchy without fine-tuning of model parameters, focusing on the charged lepton flavour violation, neutrinoless double beta decay, and electric dipole moments of charged leptons. We examine the predictions for typical ranges of associated observables such as branching ratios of rare lepton decays, and study how those experimental constraints affect the model parameter space. The most notable result is that the regions of parameter space that allow small light neutrino masses have been constrained by the present experimental bounds from charged lepton flavour violation. Furthermore, we also find that the mass of the lightest heavy neutrino should be relatively small in order to satisfy those experimental constraints.
[ { "created": "Mon, 15 May 2017 17:53:17 GMT", "version": "v1" }, { "created": "Tue, 6 Jun 2017 21:13:48 GMT", "version": "v2" } ]
2017-06-08
[ [ "Lee", "Chang-Hun", "" ] ]
We develop a systematic procedure of constructing lepton mass matrices that satisfy all the experimental constraints in the light lepton sector of the minimal left-right symmetric model with type-I seesaw dominance. This method is unique since it is applicable to the most general cases of type-I seesaw with complex electroweak vacuum expectation values in the model. With this method, we investigate the TeV-scale phenomenology in the normal hierarchy without fine-tuning of model parameters, focusing on the charged lepton flavour violation, neutrinoless double beta decay, and electric dipole moments of charged leptons. We examine the predictions for typical ranges of associated observables such as branching ratios of rare lepton decays, and study how those experimental constraints affect the model parameter space. The most notable result is that the regions of parameter space that allow small light neutrino masses have been constrained by the present experimental bounds from charged lepton flavour violation. Furthermore, we also find that the mass of the lightest heavy neutrino should be relatively small in order to satisfy those experimental constraints.
2110.03714
Davide Pagani
Davide Pagani, Marco Zaro
One-loop electroweak Sudakov logarithms: a revisitation and automation
57 pages, 8 figures, 2 tables. This version matches the one published
JHEP 02 (2022) 161
10.1007/JHEP02(2022)161
DESY-21-145, TIF-UNIMI-2021-13
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this work we revisit the algorithm of Denner and Pozzorini for the calculation of one-loop electroweak Sudakov logarithms and we automate it in the MadGraph5_aMC@NLO framework. We adapt the formulas for modern calculations, keeping light-quarks and photons strictly massless and dealing with infrared divergences via dimensional regularisation. We improve the approximation by taking into account additional logarithms that are angular dependent. We prove that an imaginary term has been previously omitted and we show that it cannot be in general neglected for $2\rightarrow n$ processes with $n> 2$. We extend the algorithm to NLO EW corrections to squared matrix-elements that involve also QCD corrections on top of subleading LO terms. Furthermore, we discuss the usage of this algorithm for approximating physical observables and cross sections. We propose a new approach in which the QED component is consistently removed and we show how it can be superior to the commonly used approaches. The relevance of all the novelties introduced in this work is corroborated by numerical results obtained for several processes in a completely automated way. We thoroughly compare exact NLO EW corrections and their Sudakov approximations both at the amplitude level and for physical observables in high-energy hadronic collisions.
[ { "created": "Thu, 7 Oct 2021 18:03:41 GMT", "version": "v1" }, { "created": "Wed, 20 Apr 2022 16:27:02 GMT", "version": "v2" } ]
2022-04-21
[ [ "Pagani", "Davide", "" ], [ "Zaro", "Marco", "" ] ]
In this work we revisit the algorithm of Denner and Pozzorini for the calculation of one-loop electroweak Sudakov logarithms and we automate it in the MadGraph5_aMC@NLO framework. We adapt the formulas for modern calculations, keeping light-quarks and photons strictly massless and dealing with infrared divergences via dimensional regularisation. We improve the approximation by taking into account additional logarithms that are angular dependent. We prove that an imaginary term has been previously omitted and we show that it cannot be in general neglected for $2\rightarrow n$ processes with $n> 2$. We extend the algorithm to NLO EW corrections to squared matrix-elements that involve also QCD corrections on top of subleading LO terms. Furthermore, we discuss the usage of this algorithm for approximating physical observables and cross sections. We propose a new approach in which the QED component is consistently removed and we show how it can be superior to the commonly used approaches. The relevance of all the novelties introduced in this work is corroborated by numerical results obtained for several processes in a completely automated way. We thoroughly compare exact NLO EW corrections and their Sudakov approximations both at the amplitude level and for physical observables in high-energy hadronic collisions.
hep-ph/0502111
Evgeni Andriyash
E.A.Andriyash, G.G.Ovanesyan, M.I.Vysotsky
The value of B_K from the experimental data on CP-violation in K-mesons and up-to-date values of CKM matrix parameters
12 pages, 1 figure
Phys.Atom.Nucl. 69 (2006) 286-292
10.1134/S106377880602013X
null
hep-ph
null
The difference between induced by box diagram quantity \tilde \epsilon and experimentally measured value of \epsilon is determined and used to obtain the value of \tilde \epsilon with high precision. Present day knowledge of CKM matrix elements (including B-factory data), allows us to obtain from the Standard Model expression for \tilde \epsilon the value of parameter B_K: B_K = 0.89 \pm0.16. It turns out to be very close to the result of vacuum insertion, B_K = 1.
[ { "created": "Fri, 11 Feb 2005 13:43:00 GMT", "version": "v1" } ]
2009-11-11
[ [ "Andriyash", "E. A.", "" ], [ "Ovanesyan", "G. G.", "" ], [ "Vysotsky", "M. I.", "" ] ]
The difference between induced by box diagram quantity \tilde \epsilon and experimentally measured value of \epsilon is determined and used to obtain the value of \tilde \epsilon with high precision. Present day knowledge of CKM matrix elements (including B-factory data), allows us to obtain from the Standard Model expression for \tilde \epsilon the value of parameter B_K: B_K = 0.89 \pm0.16. It turns out to be very close to the result of vacuum insertion, B_K = 1.
1503.00599
Maria Eugenia Cabrera Catalan
Maria Eugenia Cabrera Catalan, Shin'ichiro Ando, Christoph Weniger and Fabio Zandanel
Indirect and direct detection prospect for TeV dark matter in the MSSM-9
8 pages, 3 figures
Phys. Rev. D 92, 035018 (2015)
10.1103/PhysRevD.92.035018
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the prospects of indirect and direct dark matter searches within the minimal supersymmetric standard model with nine parameters (MSSM-9). These nine parameters include three gaugino masses, Higgs, slepton and squark masses, all treated independently. We perform a Bayesian Monte Carlo scan of the parameter space taking into consideration all available particle physics constraints such as the Higgs mass of 126 GeV, upper limits on the scattering cross-section from direct-detection experiments, and assuming that the MSSM-9 provides all the dark matter abundance through thermal freeze-out mechanism. Within this framework we find two most probable regions for dark matter: 1-TeV higgsino-like and 3-TeV wino-like neutralinos. We discuss prospects for future indirect (in particular the Cherenkov Telescope Array, CTA) and direct detection experiments. We find that for slightly contracted dark matter profiles in our Galaxy, which can be caused by the effects of baryonic infall in the Galactic center, CTA will be able to probe a large fraction of the remaining allowed region in synergy with future direct detection experiments like XENON-1T.
[ { "created": "Mon, 2 Mar 2015 16:33:19 GMT", "version": "v1" }, { "created": "Fri, 9 Oct 2015 21:54:01 GMT", "version": "v2" } ]
2015-10-13
[ [ "Catalan", "Maria Eugenia Cabrera", "" ], [ "Ando", "Shin'ichiro", "" ], [ "Weniger", "Christoph", "" ], [ "Zandanel", "Fabio", "" ] ]
We investigate the prospects of indirect and direct dark matter searches within the minimal supersymmetric standard model with nine parameters (MSSM-9). These nine parameters include three gaugino masses, Higgs, slepton and squark masses, all treated independently. We perform a Bayesian Monte Carlo scan of the parameter space taking into consideration all available particle physics constraints such as the Higgs mass of 126 GeV, upper limits on the scattering cross-section from direct-detection experiments, and assuming that the MSSM-9 provides all the dark matter abundance through thermal freeze-out mechanism. Within this framework we find two most probable regions for dark matter: 1-TeV higgsino-like and 3-TeV wino-like neutralinos. We discuss prospects for future indirect (in particular the Cherenkov Telescope Array, CTA) and direct detection experiments. We find that for slightly contracted dark matter profiles in our Galaxy, which can be caused by the effects of baryonic infall in the Galactic center, CTA will be able to probe a large fraction of the remaining allowed region in synergy with future direct detection experiments like XENON-1T.
hep-ph/9805511
Otto Kong
Otto C. W. Kong (Rochester U.), Feng-Li Lin (Virginia Tech.)
Two-Higgs-Doublet-Models and Radiative CP Violation
8 pages + cover, 3 figures incoporated, in latex with aipproc.sty /aipproc.cls, talk given by O.K. at MRST '98
null
10.1063/1.57065
UR-1531, ER/40685/918, VPI-IPPAP-98-2
hep-ph
null
We discuss the feasibility of spontaneous CP violation being induced by radiative corrections in 2HDM's. Specifically, we analyze the cases of gaugino/higgsino effect on MSSM, and a new model with an extra exotic quark doublet. The new model, while demonstrating well the Georgi-Pais theorem, is also expected to be phenomenlogically interesting.
[ { "created": "Fri, 29 May 1998 21:13:50 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kong", "Otto C. W.", "", "Rochester U." ], [ "Lin", "Feng-Li", "", "Virginia Tech." ] ]
We discuss the feasibility of spontaneous CP violation being induced by radiative corrections in 2HDM's. Specifically, we analyze the cases of gaugino/higgsino effect on MSSM, and a new model with an extra exotic quark doublet. The new model, while demonstrating well the Georgi-Pais theorem, is also expected to be phenomenlogically interesting.
1103.2689
Urko Reinosa
Urko Reinosa and Zsolt Szep
Broken phase scalar effective potential and Phi-derivable approximations
23 pages, 5 figures, uses revtex4
Phys.Rev.D83:125026,2011
10.1103/PhysRevD.83.125026
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effective potential of a real scalar phi^4 theory as a function of the temperature T within the simplest Phi-derivable approximation, namely the Hartree approximation. We apply renormalization at a "high" temperature T* where the theory is required to be in its symmetric phase and study how the effective potential evolves as the temperature is lowered down to T=0. In particular, we prove analytically that no second order phase transition can occur in this particular approximation of the theory, in agreement with earlier studies based on the numerical evaluation or the high temperature expansion of the effective potential. This work is also an opportunity to illustrate certain issues on the renormalization of Phi-derivable approximations at finite temperature and non-vanishing field expectation value, and to introduce new computational techniques which might also prove useful when dealing with higher order approximations.
[ { "created": "Mon, 14 Mar 2011 15:15:36 GMT", "version": "v1" } ]
2015-03-19
[ [ "Reinosa", "Urko", "" ], [ "Szep", "Zsolt", "" ] ]
We study the effective potential of a real scalar phi^4 theory as a function of the temperature T within the simplest Phi-derivable approximation, namely the Hartree approximation. We apply renormalization at a "high" temperature T* where the theory is required to be in its symmetric phase and study how the effective potential evolves as the temperature is lowered down to T=0. In particular, we prove analytically that no second order phase transition can occur in this particular approximation of the theory, in agreement with earlier studies based on the numerical evaluation or the high temperature expansion of the effective potential. This work is also an opportunity to illustrate certain issues on the renormalization of Phi-derivable approximations at finite temperature and non-vanishing field expectation value, and to introduce new computational techniques which might also prove useful when dealing with higher order approximations.
hep-ph/9403324
Mark Alford
Mark Alford
Critical Exponents without the Epsilon Expansion
8 pages, CLNS 94/1279, latex
Phys.Lett. B336 (1994) 237-242
10.1016/0370-2693(94)01005-6
null
hep-ph
null
We argue that the sharp-cutoff Wilson renormalization group provides a powerful tool for the analysis of second-order and weakly first-order phase transitions. In particular, in a computation no harder than the calculation of the 1-loop effective potential, we show that the Wilson RG yields the fixed point couplings and critical exponents of 3-dimensional $O(N)$ scalar field theory, with results close to those obtained in high-order $\ep$-% expansion and large-$N$ calculations. We discuss the prospects for an even more precise computation.
[ { "created": "Tue, 22 Mar 1994 00:55:06 GMT", "version": "v1" } ]
2009-10-28
[ [ "Alford", "Mark", "" ] ]
We argue that the sharp-cutoff Wilson renormalization group provides a powerful tool for the analysis of second-order and weakly first-order phase transitions. In particular, in a computation no harder than the calculation of the 1-loop effective potential, we show that the Wilson RG yields the fixed point couplings and critical exponents of 3-dimensional $O(N)$ scalar field theory, with results close to those obtained in high-order $\ep$-% expansion and large-$N$ calculations. We discuss the prospects for an even more precise computation.
2008.02673
Yuichi Uesaka
Takaaki Nomura, Hiroshi Okada, Yuichi Uesaka
A two-loop induced neutrino mass model, dark matter, and LFV processes $\ell_i \to \ell_j \gamma$, and $\mu e \to e e$ in a hidden local $U(1)$ symmetry
16 pages, 11 figures. arXiv admin note: text overlap with arXiv:2005.05527
null
10.1016/j.nuclphysb.2020.115236
KIAS-P20041, APCTP Pre2020 - 016
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a model based on a hidden $U(1)_X$ gauge symmetry in which neutrino mass is induced at two-loop level by effects of interactions among particles in hidden sector and the Standard Model leptons. Since neutrino mass is suppressed by two-loop, its associate Yukawa couplings can be sizable and it would affect lepton flavor phenomenology. We analyze neutrino mass matrix, lepton flavor violating processes, electron/muon $g-2$ and dark matter annihilation cross section which are induced via interactions among Standard Model leptons and particles in $U(1)_X$ hidden sector, and their interactions can be sizable in our scenario. Performing numerical analysis, we show expected ratios for these processes using allowed parameters which can fit the neutrino data and satisfy flavor constraints.
[ { "created": "Wed, 5 Aug 2020 09:26:22 GMT", "version": "v1" } ]
2020-12-30
[ [ "Nomura", "Takaaki", "" ], [ "Okada", "Hiroshi", "" ], [ "Uesaka", "Yuichi", "" ] ]
We discuss a model based on a hidden $U(1)_X$ gauge symmetry in which neutrino mass is induced at two-loop level by effects of interactions among particles in hidden sector and the Standard Model leptons. Since neutrino mass is suppressed by two-loop, its associate Yukawa couplings can be sizable and it would affect lepton flavor phenomenology. We analyze neutrino mass matrix, lepton flavor violating processes, electron/muon $g-2$ and dark matter annihilation cross section which are induced via interactions among Standard Model leptons and particles in $U(1)_X$ hidden sector, and their interactions can be sizable in our scenario. Performing numerical analysis, we show expected ratios for these processes using allowed parameters which can fit the neutrino data and satisfy flavor constraints.
2206.08253
Takhmasib Aliev
T.M.Aliev, S.Bilmis, M.Savci
Weak $\Xi_{QQ} \to \Sigma_Q \ell^+ \ell^-$ decays induced by FCNC in QCD
null
null
10.1140/epjc/s10052-022-10845-5
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the discovery of the doubly heavy $\Xi_{cc}$ baryon, comprehensive studies of the properties of the doubly heavy baryons are started. In the present work, we examine the $\Xi_{bb} \to \Sigma_b \ell^+ \ell^-$ and $\Xi_{cc} \to \Sigma_c \ell^+ \ell^-$ decays induced by flavor-changing neutral currents (FCNC) in the framework of the light-cone sum rules. After obtaining the sum rules for the form factors induced by the tensor current, the branching ratios of the relevant transitions are estimated. We found that the branching ratio for the $c \to u$ transition is around five orders smaller than the $b \to d$ transition. Our findings are also compared with other approaches.
[ { "created": "Thu, 16 Jun 2022 15:46:58 GMT", "version": "v1" }, { "created": "Fri, 14 Oct 2022 08:17:14 GMT", "version": "v2" } ]
2022-10-17
[ [ "Aliev", "T. M.", "" ], [ "Bilmis", "S.", "" ], [ "Savci", "M.", "" ] ]
With the discovery of the doubly heavy $\Xi_{cc}$ baryon, comprehensive studies of the properties of the doubly heavy baryons are started. In the present work, we examine the $\Xi_{bb} \to \Sigma_b \ell^+ \ell^-$ and $\Xi_{cc} \to \Sigma_c \ell^+ \ell^-$ decays induced by flavor-changing neutral currents (FCNC) in the framework of the light-cone sum rules. After obtaining the sum rules for the form factors induced by the tensor current, the branching ratios of the relevant transitions are estimated. We found that the branching ratio for the $c \to u$ transition is around five orders smaller than the $b \to d$ transition. Our findings are also compared with other approaches.
1005.0618
Diego Guadagnoli
Kiwoon Choi, Diego Guadagnoli, Sang Hui Im, Chan Beom Park
Sparticle masses from transverse mass kinks at the LHC: the case of Yukawa-unified SUSY GUTs
1+26 pages, 11 figures, 5 tables. v3: references and a few textual clarifications added. Matches journal version
JHEP 1010:025,2010
10.1007/JHEP10(2010)025
TUM-HEP-759/10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore, in a concrete example, to which extent new particle mass determinations are practicable with LHC data. Our chosen example is that of Yukawa-unified SUSY GUTs, whose viability has been recently studied for two general patterns of soft SUSY-breaking terms. We note that both patterns of SUSY spectra do not admit long decay chains, which would make it possible to determine the masses of the SUSY particles involved using endpoints or mass relations. We thus take the so-called mT2-kink method as our key strategy, since it does not rely on the presence of long decay chains. We then discuss a procedure allowing to determine the masses of the gluino, of the lightest chargino as well as of the first two neutralinos and, for the scenario where a stop is lighter than the gluino, the mass of the light stop too. Our worked example of Yukawa-unified SUSY GUTs may offer a useful playground for dealing with other theories which predict similar patterns of SUSY spectra.
[ { "created": "Tue, 4 May 2010 20:00:04 GMT", "version": "v1" }, { "created": "Wed, 12 May 2010 16:27:05 GMT", "version": "v2" }, { "created": "Sun, 17 Oct 2010 11:37:20 GMT", "version": "v3" } ]
2015-03-17
[ [ "Choi", "Kiwoon", "" ], [ "Guadagnoli", "Diego", "" ], [ "Im", "Sang Hui", "" ], [ "Park", "Chan Beom", "" ] ]
We explore, in a concrete example, to which extent new particle mass determinations are practicable with LHC data. Our chosen example is that of Yukawa-unified SUSY GUTs, whose viability has been recently studied for two general patterns of soft SUSY-breaking terms. We note that both patterns of SUSY spectra do not admit long decay chains, which would make it possible to determine the masses of the SUSY particles involved using endpoints or mass relations. We thus take the so-called mT2-kink method as our key strategy, since it does not rely on the presence of long decay chains. We then discuss a procedure allowing to determine the masses of the gluino, of the lightest chargino as well as of the first two neutralinos and, for the scenario where a stop is lighter than the gluino, the mass of the light stop too. Our worked example of Yukawa-unified SUSY GUTs may offer a useful playground for dealing with other theories which predict similar patterns of SUSY spectra.
hep-ph/9310303
Kurt Langfeld
K. Langfeld
The Non-Trivial Phase of $\phi ^{4}$-Theory in an External Magnetic Field and at Finite Temperature
12 LaTex pages (3 figures available on request), UNITUE-THEP-11-1993
null
null
null
hep-ph
null
The effective potential for the order parameter $\phi ^{\dagger } \phi$ is investigated in massless $\phi ^{4}$-theory in the presence of magnetic fields at finite temperature. It is found that the first order nature of the phase transition from the non-trivial to the perturbative ground state at a critical temperature is unchanged by the presence of magnetic fields, though they do increase the critical temperature and weaken the barrier separating the perturbative from the non-trivial phase. The results might be relevant for the electro-weak phase transition as well as for inflationary models of the early universe.
[ { "created": "Mon, 18 Oct 1993 10:13:54 GMT", "version": "v1" } ]
2009-09-25
[ [ "Langfeld", "K.", "" ] ]
The effective potential for the order parameter $\phi ^{\dagger } \phi$ is investigated in massless $\phi ^{4}$-theory in the presence of magnetic fields at finite temperature. It is found that the first order nature of the phase transition from the non-trivial to the perturbative ground state at a critical temperature is unchanged by the presence of magnetic fields, though they do increase the critical temperature and weaken the barrier separating the perturbative from the non-trivial phase. The results might be relevant for the electro-weak phase transition as well as for inflationary models of the early universe.
1902.08623
Katelin Schutz
Cora Dvorkin, Tongyan Lin, Katelin Schutz
Making dark matter out of light: freeze-in from plasma effects
23+8 pages, 8+1 figures
Phys. Rev. D 99, 115009 (2019)
10.1103/PhysRevD.99.115009
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter (DM) could couple to particles in the Standard Model (SM) through a light vector mediator. In the limit of small coupling, this portal could be responsible for producing the observed DM abundance through a mechanism known as freeze-in. Furthermore, the requisite DM-SM couplings provide a concrete benchmark for direct and indirect searches for DM. In this paper, we present updated calculations of the relic abundance for DM produced by freeze-in through a light vector mediator. We identify an additional production channel: the decay of photons that acquire an in-medium plasma mass. These plasmon decays are a dominant channel for DM production for sub-MeV DM masses, and including this channel leads to a significant reduction in the predicted signal strength for DM searches. Accounting for production from both plasmon decays and annihilations of SM fermions, the DM acquires a highly non-thermal phase space distribution which impacts the cosmology at later times; these cosmological effects will be explored in a companion paper.
[ { "created": "Fri, 22 Feb 2019 19:00:00 GMT", "version": "v1" } ]
2019-06-19
[ [ "Dvorkin", "Cora", "" ], [ "Lin", "Tongyan", "" ], [ "Schutz", "Katelin", "" ] ]
Dark matter (DM) could couple to particles in the Standard Model (SM) through a light vector mediator. In the limit of small coupling, this portal could be responsible for producing the observed DM abundance through a mechanism known as freeze-in. Furthermore, the requisite DM-SM couplings provide a concrete benchmark for direct and indirect searches for DM. In this paper, we present updated calculations of the relic abundance for DM produced by freeze-in through a light vector mediator. We identify an additional production channel: the decay of photons that acquire an in-medium plasma mass. These plasmon decays are a dominant channel for DM production for sub-MeV DM masses, and including this channel leads to a significant reduction in the predicted signal strength for DM searches. Accounting for production from both plasmon decays and annihilations of SM fermions, the DM acquires a highly non-thermal phase space distribution which impacts the cosmology at later times; these cosmological effects will be explored in a companion paper.
hep-ph/9602407
Sergio Lupia
Alberto Giovannini (Turin U. & INFN, Turin), Sergio Lupia (Munich, Max Planck Inst.), Roberto Ugoccioni (Lund U.)
Common origin of the shoulder in multiplicity distributions and of oscillations in the factorial cumulants to factorial moments ratio
LaTeX, 13 pages including 2 Postscript figures, uses epsfig.sty
Phys.Lett.B374:231-237,1996
10.1016/0370-2693(96)00258-4
DFTT 9/96, MPI-PhT/96-9, LU TP 96-7
hep-ph
null
The shoulder structure of charged particles multiplicity distributions (MD's) in full phase space in $e^+e^-$ annihilation at the $Z_0$ peak and the quasi-oscillatory behavior of the ratio of factorial cumulants over factorial moments, $H_q$, as a function of the order $q$, are quantitatively reproduced within a simple parametrization of the MD in terms of a weighted superposition of two Negative Binomial Distributions, associated to two- and multi-jet production, i.e., to hard gluons radiation.
[ { "created": "Tue, 27 Feb 1996 11:04:48 GMT", "version": "v1" } ]
2008-11-26
[ [ "Giovannini", "Alberto", "", "Turin U. & INFN, Turin" ], [ "Lupia", "Sergio", "", "Munich, Max\n Planck Inst." ], [ "Ugoccioni", "Roberto", "", "Lund U." ] ]
The shoulder structure of charged particles multiplicity distributions (MD's) in full phase space in $e^+e^-$ annihilation at the $Z_0$ peak and the quasi-oscillatory behavior of the ratio of factorial cumulants over factorial moments, $H_q$, as a function of the order $q$, are quantitatively reproduced within a simple parametrization of the MD in terms of a weighted superposition of two Negative Binomial Distributions, associated to two- and multi-jet production, i.e., to hard gluons radiation.
1211.0667
Helen Matskevich
S.M. Gerasyuta and E.E. Matskevich
Relativistic quark-gluon description of $^3 He$
19 pages. arXiv admin note: substantial text overlap with arXiv:1009.3365, arXiv:1003.0257
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The relativistic nine-quark equations are found in the framework of the dispersion relation technique. $ ^3 He$ nucleus is described by these equations. We consider the $ ^3 He$ as the system of interacting quarks and gluons. The approximate solutions of these equations using the method based on the extraction of leading singularities of the amplitudes are obtained. The relativistic nine-quark amplitudes of $ ^3 He$, including the $u$, $d$ quarks are calculated. The poles of these amplitudes determine the mass of nine-quark system. The $ ^3 He$ mass $M=2809\, MeV$ is calculated. The gluon coupling constant in the light nuclei region is equal to $g=0.1536$. The gluon interaction of $ ^3 He$ is obtained in 2 -- 3 time smaller as compared with baryon interaction.
[ { "created": "Sun, 4 Nov 2012 07:43:29 GMT", "version": "v1" } ]
2019-08-19
[ [ "Gerasyuta", "S. M.", "" ], [ "Matskevich", "E. E.", "" ] ]
The relativistic nine-quark equations are found in the framework of the dispersion relation technique. $ ^3 He$ nucleus is described by these equations. We consider the $ ^3 He$ as the system of interacting quarks and gluons. The approximate solutions of these equations using the method based on the extraction of leading singularities of the amplitudes are obtained. The relativistic nine-quark amplitudes of $ ^3 He$, including the $u$, $d$ quarks are calculated. The poles of these amplitudes determine the mass of nine-quark system. The $ ^3 He$ mass $M=2809\, MeV$ is calculated. The gluon coupling constant in the light nuclei region is equal to $g=0.1536$. The gluon interaction of $ ^3 He$ is obtained in 2 -- 3 time smaller as compared with baryon interaction.
hep-ph/0301175
Alessio Del Fabbro
A.Del Fabbro, D.Treleani
b \bar b b\bar b production in proton-nucleus collisions at the LHC
13 pages, 4 figures
null
10.1103/PhysRevD.70.034022
null
hep-ph
null
A sizable rate of events, with several pairs of $b$-quarks produced contemporarily by multiple parton interactions, may be expected at very high energies as a consequence of the large parton luminosities. The production rates are further enhanced in hadron-nucleus reactions, which may represent a convenient tool to study the phenomenon. We compare the different contributions to $b{\bar b}b{\bar b}$ production, due to single and double parton scatterings, in collisions of protons with nuclei at the CERN-LHC.
[ { "created": "Tue, 21 Jan 2003 14:16:21 GMT", "version": "v1" } ]
2013-05-29
[ [ "Del Fabbro", "A.", "" ], [ "Treleani", "D.", "" ] ]
A sizable rate of events, with several pairs of $b$-quarks produced contemporarily by multiple parton interactions, may be expected at very high energies as a consequence of the large parton luminosities. The production rates are further enhanced in hadron-nucleus reactions, which may represent a convenient tool to study the phenomenon. We compare the different contributions to $b{\bar b}b{\bar b}$ production, due to single and double parton scatterings, in collisions of protons with nuclei at the CERN-LHC.
hep-ph/0105328
Akushevich Igor
A.V. Afanasev, I. Akushevich, A.Ilyichev, N.P.Merenkov
QED Radiative Corrections to Asymmetries of Elastic ep-scattering in Hadronic Variables
9 pages, 5 figures
Phys.Lett.B514:269-278,2001
10.1016/S0370-2693(01)00816-4
null
hep-ph
null
Compact analytical formulae for QED radiative corrections in the processes of elastic $e-p$ scattering are obtained in the case when kinematic variables are reconstructed from the recoil proton momentum measured. Numerical analysis is presented under kinematic conditions of current experiments at JLab.
[ { "created": "Wed, 30 May 2001 20:45:52 GMT", "version": "v1" } ]
2014-11-17
[ [ "Afanasev", "A. V.", "" ], [ "Akushevich", "I.", "" ], [ "Ilyichev", "A.", "" ], [ "Merenkov", "N. P.", "" ] ]
Compact analytical formulae for QED radiative corrections in the processes of elastic $e-p$ scattering are obtained in the case when kinematic variables are reconstructed from the recoil proton momentum measured. Numerical analysis is presented under kinematic conditions of current experiments at JLab.
hep-ph/0001075
John Tjon
Yu.A. Simonov (ITEP,Moscow, Russia), J.A. Tjon (ITP,U. Utrecht,The Netherlands)
String formation and chiral symmetry breaking in the heavy-light quark-antiquark system in QCD
17 pages Revtex, 3 figures
Phys.Rev. D62 (2000) 014501
10.1103/PhysRevD.62.014501
null
hep-ph
null
The effective quark Lagrangian is written for a light quark in the field of a static antiquark, explicitly containing field correlators as coefficient functions of products of quark operators. At large N_c the closed system of equations for the gauge-invariant quark Green's function in the field of static source is examined analytically. The formation of the string connecting the light quark to the static source is observed numerically. The scalar Lorentz nature of the resulting confinement is shown to hold for the considered case, implying chiral symmetry breaking. The resulting spectrum with and without perturbative gluon exchanges is obtained numerically and compared to the B and D meson masses and HQET.
[ { "created": "Mon, 10 Jan 2000 20:50:50 GMT", "version": "v1" } ]
2009-10-31
[ [ "Simonov", "Yu. A.", "", "ITEP,Moscow, Russia" ], [ "Tjon", "J. A.", "", "ITP,U. Utrecht,The\n Netherlands" ] ]
The effective quark Lagrangian is written for a light quark in the field of a static antiquark, explicitly containing field correlators as coefficient functions of products of quark operators. At large N_c the closed system of equations for the gauge-invariant quark Green's function in the field of static source is examined analytically. The formation of the string connecting the light quark to the static source is observed numerically. The scalar Lorentz nature of the resulting confinement is shown to hold for the considered case, implying chiral symmetry breaking. The resulting spectrum with and without perturbative gluon exchanges is obtained numerically and compared to the B and D meson masses and HQET.
hep-ph/0404251
Puneet Batra
Puneet Batra, Antonio Delgado, David E. Kaplan, Tim M.P. Tait
Running into New Territory in SUSY Parameter Space
15 pages, 5 figures; Typo in equation (4.5) corrected; submitted to JHEP
JHEP 0406:032,2004
10.1088/1126-6708/2004/06/032
FERMILAB-PUB-04/038-T, SU-ITP-04/12
hep-ph
null
The LEP-II bound on the light Higgs mass rules out the vast majority of parameter space left to the Minimal Supersymmetric Standard Model (MSSM) with weak-scale soft-masses. This suggests the importance of exploring extensions of the MSSM with non-minimal Higgs physics. In this article, we explore a theory with an additional singlet superfield and an extended gauge sector. The theory has a number of novel features compared to both the MSSM and Next-to-MSSM, including easily realizing a light CP-even Higgs mass consistent with LEP-II limits, tan(beta) < 1, and a lightest Higgs which is charged. These features are achieved while remaining consistent with perturbative unification and without large stop-masses. Discovery modes at the Tevatron and LHC are discussed.
[ { "created": "Wed, 28 Apr 2004 00:02:30 GMT", "version": "v1" }, { "created": "Tue, 4 May 2004 17:43:09 GMT", "version": "v2" } ]
2010-02-03
[ [ "Batra", "Puneet", "" ], [ "Delgado", "Antonio", "" ], [ "Kaplan", "David E.", "" ], [ "Tait", "Tim M. P.", "" ] ]
The LEP-II bound on the light Higgs mass rules out the vast majority of parameter space left to the Minimal Supersymmetric Standard Model (MSSM) with weak-scale soft-masses. This suggests the importance of exploring extensions of the MSSM with non-minimal Higgs physics. In this article, we explore a theory with an additional singlet superfield and an extended gauge sector. The theory has a number of novel features compared to both the MSSM and Next-to-MSSM, including easily realizing a light CP-even Higgs mass consistent with LEP-II limits, tan(beta) < 1, and a lightest Higgs which is charged. These features are achieved while remaining consistent with perturbative unification and without large stop-masses. Discovery modes at the Tevatron and LHC are discussed.
1710.05775
Shivaramakrishna Singirala
Shivaramakrishna Singirala, Rukmani Mohanta, Sudhanwa Patra, Soumya Rao
Majorana Dark Matter in a new B-L model
20 pages, 7 figures, version to appear in JCAP
null
10.1088/1475-7516/2018/11/026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive study of Majorana dark matter in a $U(1)_{B-L}$ gauge extension of the standard model, where three exotic fermions with $B-L$ charges as $-4, -4, +5$ are added to make the model free from the triangle gauge anomalies. The enriched scalar sector and the new heavy gauge boson $Z^{\prime},$ associated with the $U(1)_{B-L}$ symmetry make the model advantageous to be explored in dual portal scenarios for the search of dark matter signal. Diagonalizing the exotic fermion mass matrix, we obtain the Majorana mass eigenstates, of which the lightest one plays the role of dark matter. Analyzing the effect of two mediators separately, the scalar portal channels give a viable parameter space consistent with relic density from PLANCK data and the direct detection limits from various experiments such as LUX, XENON1T and PandaX. While the $Z^{\prime}$ mediated channels are constrained from relic abundance and LHC searches for $Z^{\prime}$ in the dilepton channel. A massless physical Goldstone boson plays a key role in the scalar portal relic density. Finally, we briefly discuss the neutrino mass generation at one-loop level.
[ { "created": "Mon, 16 Oct 2017 15:13:50 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2018 11:40:16 GMT", "version": "v2" } ]
2018-11-28
[ [ "Singirala", "Shivaramakrishna", "" ], [ "Mohanta", "Rukmani", "" ], [ "Patra", "Sudhanwa", "" ], [ "Rao", "Soumya", "" ] ]
We present a comprehensive study of Majorana dark matter in a $U(1)_{B-L}$ gauge extension of the standard model, where three exotic fermions with $B-L$ charges as $-4, -4, +5$ are added to make the model free from the triangle gauge anomalies. The enriched scalar sector and the new heavy gauge boson $Z^{\prime},$ associated with the $U(1)_{B-L}$ symmetry make the model advantageous to be explored in dual portal scenarios for the search of dark matter signal. Diagonalizing the exotic fermion mass matrix, we obtain the Majorana mass eigenstates, of which the lightest one plays the role of dark matter. Analyzing the effect of two mediators separately, the scalar portal channels give a viable parameter space consistent with relic density from PLANCK data and the direct detection limits from various experiments such as LUX, XENON1T and PandaX. While the $Z^{\prime}$ mediated channels are constrained from relic abundance and LHC searches for $Z^{\prime}$ in the dilepton channel. A massless physical Goldstone boson plays a key role in the scalar portal relic density. Finally, we briefly discuss the neutrino mass generation at one-loop level.
hep-ph/0002234
Marco Fabbrichesi
Stefano Bertolini, Jan O. Eeg and Marco Fabbrichesi
An updated analysis of eps'/eps in the standard model with hadronic matrix elements from the chiral quark model
15 pages, 11 figures, RevTeX, discussion updated, refs added
Phys.Rev.D63:056009,2001
10.1103/PhysRevD.63.056009
null
hep-ph
null
We discuss the theoretical and experimental status of the CP violating ratio eps'/eps. We revise our 1997 standard-model estimate-based on hadronic matrix elements computed in the chiral quark model up to O(p^4) in the chiral expansion-by including an improved statistical analysis of the uncertainties and updated determination of the Cabibbo-Kobayashi-Maskawa elements and other short-distance parameters. Using normal distributions for the experimental input data we find Re eps'/eps = (2.2 \pm 0.8) x 10^{-3}, whereas a flat scanning gives 0.9 x 10^{-3} < Re eps'/eps < 4.8 x 10^{-3}. Both results are in agreement with the current experimental data. The key element in our estimate is, as before, the fit of the Delta I=1/2 rule, which allows us to absorb most of the theoretical uncertainties in the determination of the model-dependent parameters in the hadronic matrix elements. Our semi-phenomenological approach leads to numerical stability against variations of the renormalization scale and scheme dependence of the short- and long-distance components. The same dynamical mechanism at work in the selection rule also explains the larger value obtained for \ratio with respect to other estimates. A coherent picture of K -> pi pi decays is thus provided.
[ { "created": "Wed, 23 Feb 2000 17:54:16 GMT", "version": "v1" }, { "created": "Tue, 14 Mar 2000 13:39:42 GMT", "version": "v2" }, { "created": "Wed, 28 Jun 2000 15:57:31 GMT", "version": "v3" }, { "created": "Tue, 11 Jul 2000 11:00:50 GMT", "version": "v4" }, { "c...
2014-11-17
[ [ "Bertolini", "Stefano", "" ], [ "Eeg", "Jan O.", "" ], [ "Fabbrichesi", "Marco", "" ] ]
We discuss the theoretical and experimental status of the CP violating ratio eps'/eps. We revise our 1997 standard-model estimate-based on hadronic matrix elements computed in the chiral quark model up to O(p^4) in the chiral expansion-by including an improved statistical analysis of the uncertainties and updated determination of the Cabibbo-Kobayashi-Maskawa elements and other short-distance parameters. Using normal distributions for the experimental input data we find Re eps'/eps = (2.2 \pm 0.8) x 10^{-3}, whereas a flat scanning gives 0.9 x 10^{-3} < Re eps'/eps < 4.8 x 10^{-3}. Both results are in agreement with the current experimental data. The key element in our estimate is, as before, the fit of the Delta I=1/2 rule, which allows us to absorb most of the theoretical uncertainties in the determination of the model-dependent parameters in the hadronic matrix elements. Our semi-phenomenological approach leads to numerical stability against variations of the renormalization scale and scheme dependence of the short- and long-distance components. The same dynamical mechanism at work in the selection rule also explains the larger value obtained for \ratio with respect to other estimates. A coherent picture of K -> pi pi decays is thus provided.
2110.08921
Anthony E. Mirasola
Kay Kirkpatrick and Anthony E. Mirasola and Chanda Prescod-Weinstein
Analysis of Bose-Einstein condensation times for self-interacting scalar dark matter
5 pages, 1 figure
Phys. Rev. D 106, 043512 (2022)
10.1103/PhysRevD.106.043512
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We investigate the condensation time of self-interacting axion-like particles in a gravitational well, extending the prior work [arXiv:2007.07438] which showed that the Wigner formalism is a good analytic approach to describe a condensing scalar field. In the present work, we use this formalism to affirm that $\phi^4$ self-interactions will take longer than necessary to support the time scales associated with structure formation, making gravity a necessary part of the process to bring axion dark matter into a solitonic form. Here we show that when the axions' virial velocity is taken into account, the time scale associated with self-interactions will scale as $\lambda^2$. This is consistent with recent numerical estimates, and it confirms that the Wigner formalism described in prior work~\cite{Relax} is a helpful analytic framework to check computational work for potential numerical artifacts.
[ { "created": "Sun, 17 Oct 2021 21:12:09 GMT", "version": "v1" }, { "created": "Tue, 30 Aug 2022 13:51:36 GMT", "version": "v2" } ]
2022-08-31
[ [ "Kirkpatrick", "Kay", "" ], [ "Mirasola", "Anthony E.", "" ], [ "Prescod-Weinstein", "Chanda", "" ] ]
We investigate the condensation time of self-interacting axion-like particles in a gravitational well, extending the prior work [arXiv:2007.07438] which showed that the Wigner formalism is a good analytic approach to describe a condensing scalar field. In the present work, we use this formalism to affirm that $\phi^4$ self-interactions will take longer than necessary to support the time scales associated with structure formation, making gravity a necessary part of the process to bring axion dark matter into a solitonic form. Here we show that when the axions' virial velocity is taken into account, the time scale associated with self-interactions will scale as $\lambda^2$. This is consistent with recent numerical estimates, and it confirms that the Wigner formalism described in prior work~\cite{Relax} is a helpful analytic framework to check computational work for potential numerical artifacts.
1901.01304
J. Lorenzo Diaz-Cruz
M. A. Arroyo-Urena (1), J. Lorenzo Diaz-Cruz (2 and 3), Bryan O. Larios-Lopez (2 and 4), M. A. Perez-de Leon (3) ( (1) Facultad de Estudios Superiores Cuautitlan -UNAM, (2) Mesoamerican Center for Theoretical Physics, UNACH, (3) CIFFU and Facultad de Ciencias F\'isico - Matem\'aticas, BUAP, (4) Departamento de Gravitaci\'on y Altas Energ\'ias, Facultad de Ciencias, Universidad Nacional Aut\'onoma de Honduras )
A Private SUSY 4HDM with FCNC in the Up-sector
Version accepted in Chin. Phys. C, new author added, 23 pages, with 17 figures, 2 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a SUSY model with four Higgs doublets of the ``private type", where each fermion type (up, down, and charged leptons) obtain their masses from a different Higgs doublet H_f ( f = u_1, d, e). The conditions for anomaly cancellation, imply that the remaining Higgs doublet of the model (H_{u_2}), must have the same hypercharge as H_{u_1}, and thus can only couple to up-type quarks, which opens the possibility to have FCNC's only in this sector. We study the Lagrangian of the model, and in particular the Higgs potential, in order to identify the Higgs mass-eigenstates and their interactions; for the Yukawa matrices we consider the 4-texture case. We obtain constraints on the model parameters by using LHC measurements on the properties of the 125 GeV Higgs boson ($h$), and identify viable regions of parameter space. These constraints are then used to evaluate the prospects to detect the FCNC decay mode t -> ch at the future high-luminosity (HL) option for the LHC, which are compared with current limits from LHC-run2. Then, we also evaluate the FCNC decay of the next heavier Higgs boson H_2 -> tc, which can reach typically BR(H_2 -> tc) = O(10^{-4}-10^{-5} ); the search for the signal at HL-LHC is also studied, finding that it could be detectable for some specific regions of the model parameter space.
[ { "created": "Fri, 4 Jan 2019 20:37:41 GMT", "version": "v1" }, { "created": "Wed, 11 Dec 2019 16:52:39 GMT", "version": "v2" }, { "created": "Mon, 23 Nov 2020 11:16:58 GMT", "version": "v3" } ]
2020-11-24
[ [ "Arroyo-Urena", "M. A.", "", "2 and 3" ], [ "Diaz-Cruz", "J. Lorenzo", "", "2 and 3" ], [ "Larios-Lopez", "Bryan O.", "", "2 and 4" ], [ "Leon", "M. A. Perez-de", "" ] ]
We present a SUSY model with four Higgs doublets of the ``private type", where each fermion type (up, down, and charged leptons) obtain their masses from a different Higgs doublet H_f ( f = u_1, d, e). The conditions for anomaly cancellation, imply that the remaining Higgs doublet of the model (H_{u_2}), must have the same hypercharge as H_{u_1}, and thus can only couple to up-type quarks, which opens the possibility to have FCNC's only in this sector. We study the Lagrangian of the model, and in particular the Higgs potential, in order to identify the Higgs mass-eigenstates and their interactions; for the Yukawa matrices we consider the 4-texture case. We obtain constraints on the model parameters by using LHC measurements on the properties of the 125 GeV Higgs boson ($h$), and identify viable regions of parameter space. These constraints are then used to evaluate the prospects to detect the FCNC decay mode t -> ch at the future high-luminosity (HL) option for the LHC, which are compared with current limits from LHC-run2. Then, we also evaluate the FCNC decay of the next heavier Higgs boson H_2 -> tc, which can reach typically BR(H_2 -> tc) = O(10^{-4}-10^{-5} ); the search for the signal at HL-LHC is also studied, finding that it could be detectable for some specific regions of the model parameter space.
1811.04089
Srimoyee Sen
Larry D. McLerran, S\"oren Schlichting, Srimoyee Sen
Space-Time Picture of Baryon Stopping in the Color-Glass Condensate
Reference added
Phys. Rev. D 99, 074009 (2019)
10.1103/PhysRevD.99.074009
INT-PUB-18-055
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss baryon stopping in the Color Glass Condensate description of high energy scattering. We consider the scattering of a distribution of valence quarks on an ultra-relativistic sheet of colored charge. We compute the distribution of scattered quarks from a composite projectile, and calculate the baryon currents before and after the collisions and on an event by event basis. We obtain simple analytic estimates of the baryon number compression and rapidity shifts, which in the idealized case of plane wave scattering, produce results that agree with considerations of Anishetty-Koehler-McLerran.
[ { "created": "Fri, 9 Nov 2018 19:00:42 GMT", "version": "v1" }, { "created": "Wed, 28 Nov 2018 20:02:03 GMT", "version": "v2" } ]
2019-04-17
[ [ "McLerran", "Larry D.", "" ], [ "Schlichting", "Sören", "" ], [ "Sen", "Srimoyee", "" ] ]
We discuss baryon stopping in the Color Glass Condensate description of high energy scattering. We consider the scattering of a distribution of valence quarks on an ultra-relativistic sheet of colored charge. We compute the distribution of scattered quarks from a composite projectile, and calculate the baryon currents before and after the collisions and on an event by event basis. We obtain simple analytic estimates of the baryon number compression and rapidity shifts, which in the idealized case of plane wave scattering, produce results that agree with considerations of Anishetty-Koehler-McLerran.
1408.2517
Martin Hoferichter
Gilberto Colangelo, Martin Hoferichter, Bastian Kubis, Massimiliano Procura, Peter Stoffer
Towards a data-driven analysis of hadronic light-by-light scattering
7 pages, 4 figures, 2 tables, journal version
null
10.1016/j.physletb.2014.09.021
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of on-shell form factors and scattering amplitudes that are in principle accessible in experiment. We briefly review the main ideas behind this framework and discuss the various experimental ingredients needed for the evaluation of one- and two-pion intermediate states. In particular, we identify processes that in the absence of data for doubly-virtual pion-photon interactions can help constrain parameters in the dispersive reconstruction of the relevant input quantities, the pion transition form factor and the helicity partial waves for $\gamma^*\gamma^*\to\pi\pi$.
[ { "created": "Mon, 11 Aug 2014 20:00:01 GMT", "version": "v1" }, { "created": "Tue, 16 Sep 2014 08:12:23 GMT", "version": "v2" } ]
2015-06-22
[ [ "Colangelo", "Gilberto", "" ], [ "Hoferichter", "Martin", "" ], [ "Kubis", "Bastian", "" ], [ "Procura", "Massimiliano", "" ], [ "Stoffer", "Peter", "" ] ]
The hadronic light-by-light contribution to the anomalous magnetic moment of the muon was recently analyzed in the framework of dispersion theory, providing a systematic formalism where all input quantities are expressed in terms of on-shell form factors and scattering amplitudes that are in principle accessible in experiment. We briefly review the main ideas behind this framework and discuss the various experimental ingredients needed for the evaluation of one- and two-pion intermediate states. In particular, we identify processes that in the absence of data for doubly-virtual pion-photon interactions can help constrain parameters in the dispersive reconstruction of the relevant input quantities, the pion transition form factor and the helicity partial waves for $\gamma^*\gamma^*\to\pi\pi$.
hep-ph/0204319
Urjit A. Yajnik
J.M. Cline (McGill), U.A. Yajnik, S.N. Nayak and M. Rabikumar (I.I.T., Bombay)
Transient domain walls and lepton asymmetry in the Left-Right symmetric model
v2 version accepted for publication in Phys. Rev. D. Discussion in Introduction and Conclusion sharpened. Equation (12) corrected. 16 pages, 3 figure files, RevTeX4 style
Phys.Rev. D66 (2002) 065001
10.1103/PhysRevD.66.065001
null
hep-ph
null
It is shown that the dynamics of domain walls in Left-Right symmetric models, separating respective regions of unbroken SU(2)_L and SU(2)_R in the early universe, can give rise to baryogenesis via leptogenesis. Neutrinos have a spatially varying complex mass matrix due to CP-violating scalar condensates in the domain wall. The motion of the wall through the plasma generates a flux of lepton number across the wall which is converted to a lepton asymmetry by helicity-flipping scatterings. Subsequent processing of the lepton excess by sphalerons results in the observed baryon asymmetry, for a range of parameters in Left-Right symmetric models.
[ { "created": "Sat, 27 Apr 2002 12:10:50 GMT", "version": "v1" }, { "created": "Sun, 28 Jul 2002 19:08:10 GMT", "version": "v2" } ]
2009-11-07
[ [ "Cline", "J. M.", "", "McGill" ], [ "Yajnik", "U. A.", "", "I.I.T.,\n Bombay" ], [ "Nayak", "S. N.", "", "I.I.T.,\n Bombay" ], [ "Rabikumar", "M.", "", "I.I.T.,\n Bombay" ] ]
It is shown that the dynamics of domain walls in Left-Right symmetric models, separating respective regions of unbroken SU(2)_L and SU(2)_R in the early universe, can give rise to baryogenesis via leptogenesis. Neutrinos have a spatially varying complex mass matrix due to CP-violating scalar condensates in the domain wall. The motion of the wall through the plasma generates a flux of lepton number across the wall which is converted to a lepton asymmetry by helicity-flipping scatterings. Subsequent processing of the lepton excess by sphalerons results in the observed baryon asymmetry, for a range of parameters in Left-Right symmetric models.
2308.05860
David Curtin
David Curtin and Jaipratap Singh Grewal
Long Lived Particle Decays in MATHUSLA
17 pages + references, 11 Figures. Detector FastSim and Event Library publicly available. v2: minor tweaks, no changes to conclusion, published version
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We carefully study the decay and reconstruction of long-lived particle (LLP) decays in the proposed MATHUSLA LLP detector for the HL-LHC. Our investigations are focused on three LLP benchmark models. MATHUSLA's primary physics target is represented by hadronically decaying LLPs with mass above $\sim$ $10~\mathrm{GeV}$, produced in exotic Higgs decays. We also investigate GeV-scale scalar and right-handed-neutrino LLPs, which are the target of many other proposed experiments. We first introduce a public MATHUSLA FastSim code to allow for efficient signal-only studies of LLP decays in MATHUSLA and general external LLP detectors. For each of our benchmark scenarios, we carefully simulate LLP production and decay, and make our simulation library publicly accessible for future investigations and comparisons with other experiments. We then systematically study the geometric acceptance of MATHUSLA for LLP decays in these scenarios, and present updated sensitivity projections that include these acceptances. Our results show that the idealized reach of MATHUSLA computed in earlier studies is mostly realized. We also investigate possible ways of increasing the signal acceptance using the inherent geometric flexibility of the FastSim, which will provide useful inputs for realistic experimental and engineering optimization of the detector in the future.
[ { "created": "Thu, 10 Aug 2023 21:26:28 GMT", "version": "v1" }, { "created": "Sun, 12 May 2024 17:12:07 GMT", "version": "v2" } ]
2024-05-14
[ [ "Curtin", "David", "" ], [ "Grewal", "Jaipratap Singh", "" ] ]
We carefully study the decay and reconstruction of long-lived particle (LLP) decays in the proposed MATHUSLA LLP detector for the HL-LHC. Our investigations are focused on three LLP benchmark models. MATHUSLA's primary physics target is represented by hadronically decaying LLPs with mass above $\sim$ $10~\mathrm{GeV}$, produced in exotic Higgs decays. We also investigate GeV-scale scalar and right-handed-neutrino LLPs, which are the target of many other proposed experiments. We first introduce a public MATHUSLA FastSim code to allow for efficient signal-only studies of LLP decays in MATHUSLA and general external LLP detectors. For each of our benchmark scenarios, we carefully simulate LLP production and decay, and make our simulation library publicly accessible for future investigations and comparisons with other experiments. We then systematically study the geometric acceptance of MATHUSLA for LLP decays in these scenarios, and present updated sensitivity projections that include these acceptances. Our results show that the idealized reach of MATHUSLA computed in earlier studies is mostly realized. We also investigate possible ways of increasing the signal acceptance using the inherent geometric flexibility of the FastSim, which will provide useful inputs for realistic experimental and engineering optimization of the detector in the future.
2404.17574
Sagar Airen
Kaustubh Agashe, Sagar Airen, Roberto Franceschini, Doojin Kim, Ashutosh V. Kotwal, Lorenzo Ricci, Deepak Sathyan
"Unification" of BSM Searches and SM Measurements: the case of lepton$+MET$ and $m_W$
25 pages, 8 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop the idea that the unprecedented precision in Standard Model (SM) measurements, with further improvement at the HL-LHC, enables new searches for physics Beyond the Standard Model (BSM).As an illustration, we demonstrate that the measured kinematic distributions of the lepton$+MET$ final state not only determine the mass of the $W$ boson, but are also sensitive to light new physics. Such a search for new physics thus requires a simultaneous fit to the BSM and SM parameters, "unifying" searches and measurements at the LHC and Tevatron. In this paper, we complete the program initiated in our earlier work arXiv:2310.13687. In particular, we analyze ($i$) novel decay modes of the $W$ boson with a neutrinophilic invisible scalar or with a heavy neutrino; ($ii$) modified production of $W$ bosons, namely, associated with a hadrophilic invisible $Z^\prime$ gauge boson; and ($iii$) scenarios without an on-shell $W$ boson, such as slepton-sneutrino production in the Minimal Supersymmetric Standard Model (MSSM). Here, we complement our previous MSSM analysis in arXiv:2310.13687 by considering a different kinematic region. Our results highlight that new physics can still be directly discovered at the LHC, including light new physics,via SM precision measurements. Furthermore, we illustrate that such BSM signals are subtle, yet potentially large enough to affect the precision measurements of SM parameters themselves, such as the $W$ boson mass.
[ { "created": "Fri, 26 Apr 2024 17:56:45 GMT", "version": "v1" } ]
2024-04-30
[ [ "Agashe", "Kaustubh", "" ], [ "Airen", "Sagar", "" ], [ "Franceschini", "Roberto", "" ], [ "Kim", "Doojin", "" ], [ "Kotwal", "Ashutosh V.", "" ], [ "Ricci", "Lorenzo", "" ], [ "Sathyan", "Deepak", "" ] ]
We develop the idea that the unprecedented precision in Standard Model (SM) measurements, with further improvement at the HL-LHC, enables new searches for physics Beyond the Standard Model (BSM).As an illustration, we demonstrate that the measured kinematic distributions of the lepton$+MET$ final state not only determine the mass of the $W$ boson, but are also sensitive to light new physics. Such a search for new physics thus requires a simultaneous fit to the BSM and SM parameters, "unifying" searches and measurements at the LHC and Tevatron. In this paper, we complete the program initiated in our earlier work arXiv:2310.13687. In particular, we analyze ($i$) novel decay modes of the $W$ boson with a neutrinophilic invisible scalar or with a heavy neutrino; ($ii$) modified production of $W$ bosons, namely, associated with a hadrophilic invisible $Z^\prime$ gauge boson; and ($iii$) scenarios without an on-shell $W$ boson, such as slepton-sneutrino production in the Minimal Supersymmetric Standard Model (MSSM). Here, we complement our previous MSSM analysis in arXiv:2310.13687 by considering a different kinematic region. Our results highlight that new physics can still be directly discovered at the LHC, including light new physics,via SM precision measurements. Furthermore, we illustrate that such BSM signals are subtle, yet potentially large enough to affect the precision measurements of SM parameters themselves, such as the $W$ boson mass.
hep-ph/0206018
Chris Quigg
Estia J. Eichten, Kenneth Lane, Chris Quigg
B-Meson Gateways to Missing Charmonium Levels
5 pages, uses ReVTeX and BibTeX
Phys.Rev.Lett.89:162002,2002
10.1103/PhysRevLett.89.162002
FERMILAB-PUB-02/104-T, BUHEP-02-25
hep-ph
null
We outline a coherent strategy for exploring the four remaining narrow charmonium states [$\eta_{c}^{\prime}(2\slj{1}{1}{0})$, $h_{c}(1\slj{1}{2}{1})$, $\eta_{c2}(1\slj{1}{3}{2})$, and $\psi_{2}(1\slj{3}{3}{2})$] expected to lie below charm threshold. Produced in $B$-meson decays, these levels should be identifiable \textit{now} via striking radiative transitions among charmonium levels and in exclusive final states of kaons and pions. Their production and decay rates will provide much needed new tests for theoretical descriptions of heavy quarkonia.
[ { "created": "Mon, 3 Jun 2002 20:10:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Eichten", "Estia J.", "" ], [ "Lane", "Kenneth", "" ], [ "Quigg", "Chris", "" ] ]
We outline a coherent strategy for exploring the four remaining narrow charmonium states [$\eta_{c}^{\prime}(2\slj{1}{1}{0})$, $h_{c}(1\slj{1}{2}{1})$, $\eta_{c2}(1\slj{1}{3}{2})$, and $\psi_{2}(1\slj{3}{3}{2})$] expected to lie below charm threshold. Produced in $B$-meson decays, these levels should be identifiable \textit{now} via striking radiative transitions among charmonium levels and in exclusive final states of kaons and pions. Their production and decay rates will provide much needed new tests for theoretical descriptions of heavy quarkonia.
hep-ph/0609300
Emi Kou
J.-M. Gerard and E. Kou
Anomalous enhancement of a penguin hadronic matrix element in B->K eta'
5 pages, 1 figure
Phys.Rev.lett.97:261804,2006
10.1103/PhysRevLett.97.261804
CP3-06-15
hep-ph
null
We estimate the density matrix element for the pi^0, eta and eta' production from the vacuum in the large-N_c limit. As a consequence, we find that the QCD axial anomaly leads to highly non-trivial corrections to the usual flavour SU(3) relations between B^0-> K^0 pi^0, B^0-> K^0 eta and B^0-> K^0 eta' decay amplitudes. These corrections may explain why the B-> K eta' branching ratio is about six times larger than the B-> K pi one.
[ { "created": "Thu, 28 Sep 2006 17:25:03 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gerard", "J. -M.", "" ], [ "Kou", "E.", "" ] ]
We estimate the density matrix element for the pi^0, eta and eta' production from the vacuum in the large-N_c limit. As a consequence, we find that the QCD axial anomaly leads to highly non-trivial corrections to the usual flavour SU(3) relations between B^0-> K^0 pi^0, B^0-> K^0 eta and B^0-> K^0 eta' decay amplitudes. These corrections may explain why the B-> K eta' branching ratio is about six times larger than the B-> K pi one.
1102.2347
Marina Nielsen
Stefano I. Finazzo, Xiang Liu, Marina Nielsen
QCD sum rule calculation for the charmonium-like structures in the J/psi phi and J/psi omega invariant mass spectra
version to appear in Phys. Lett. B
Phys.Lett.B701:101-106,2011
10.1016/j.physletb.2011.05.042
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the QCD sum rules we test if the charmonium-like structure Y(4274), observed in the $J/\psi\phi$ invariant mass spectrum, can be described with a $D_s\bar{D}_{s0}(2317)+h.c.$ molecular current with $J^{PC}=0^{-+}$. We consider the contributions of condensates up to dimension ten and we work at leading order in $\alpha_s$. We keep terms which are linear in the strange quark mass $m_s$. The mass obtained for such state is $m_{D_s{D}_{s0}}=(4.80\pm 0.55)$ GeV. We also consider a molecular $0^{-+}$ $D\bar{D}_{0}(2400)+h.c.$ current and we obtain $m_{D{D}_0}=(4.61\pm 0.71)$ GeV. Our study shows that the newly observed Y(4274) in the $J/\psi\phi$ invariant mass spectra can be, considering the uncertainties, described using a molecular charmonium current.
[ { "created": "Fri, 11 Feb 2011 13:56:17 GMT", "version": "v1" }, { "created": "Mon, 16 May 2011 15:17:06 GMT", "version": "v2" } ]
2015-03-18
[ [ "Finazzo", "Stefano I.", "" ], [ "Liu", "Xiang", "" ], [ "Nielsen", "Marina", "" ] ]
Using the QCD sum rules we test if the charmonium-like structure Y(4274), observed in the $J/\psi\phi$ invariant mass spectrum, can be described with a $D_s\bar{D}_{s0}(2317)+h.c.$ molecular current with $J^{PC}=0^{-+}$. We consider the contributions of condensates up to dimension ten and we work at leading order in $\alpha_s$. We keep terms which are linear in the strange quark mass $m_s$. The mass obtained for such state is $m_{D_s{D}_{s0}}=(4.80\pm 0.55)$ GeV. We also consider a molecular $0^{-+}$ $D\bar{D}_{0}(2400)+h.c.$ current and we obtain $m_{D{D}_0}=(4.61\pm 0.71)$ GeV. Our study shows that the newly observed Y(4274) in the $J/\psi\phi$ invariant mass spectra can be, considering the uncertainties, described using a molecular charmonium current.
0707.1234
Dr. Rukmani Mohanta
R. Mohanta, A. K. Giri
Unparticle effect on B_s - \bar B_s mixing and its implications for B_s \to J/\psi \phi, \phi \phi decays
14 pages, 4 figures, version to be published in Phys. Rev. D
Phys.Rev.D76:075015,2007
10.1103/PhysRevD.76.075015
null
hep-ph
null
We study the effect of unparticle stuff on $B_s - \bar{B}_s$ mixing and consider possible implications of it for the decaymodes $B_s \to J/\psi \phi$ and $\phi \phi$. We find that due to the new contributions from the unparticles the $B_s - \bar{B}_s$ mixing phase could be observable at the LHC along with the possible sizable CP asymmetry parameters $S_{\psi \phi(\phi \phi)}$ in $B_s \to J/\psi \phi(\phi \phi)$ decay modes.
[ { "created": "Mon, 9 Jul 2007 12:08:02 GMT", "version": "v1" }, { "created": "Tue, 17 Jul 2007 06:23:23 GMT", "version": "v2" }, { "created": "Wed, 19 Sep 2007 05:57:30 GMT", "version": "v3" } ]
2008-11-26
[ [ "Mohanta", "R.", "" ], [ "Giri", "A. K.", "" ] ]
We study the effect of unparticle stuff on $B_s - \bar{B}_s$ mixing and consider possible implications of it for the decaymodes $B_s \to J/\psi \phi$ and $\phi \phi$. We find that due to the new contributions from the unparticles the $B_s - \bar{B}_s$ mixing phase could be observable at the LHC along with the possible sizable CP asymmetry parameters $S_{\psi \phi(\phi \phi)}$ in $B_s \to J/\psi \phi(\phi \phi)$ decay modes.
1111.1239
Ben Heidenreich
Csaba Cs\'aki, Yuval Grossman, Ben Heidenreich
MFV SUSY: A Natural Theory for R-Parity Violation
41 pages, 14 figures; v3: minor corrections, matches published version
Phys. Rev. D 85, 095009 (2012)
10.1103/PhysRevD.85.095009
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an alternative approach to low-energy supersymmetry. Instead of imposing R-parity we apply the minimal flavor violation (MFV) hypothesis to the R-parity violating MSSM. In this framework, which we call MFV SUSY, squarks can be light and the proton long lived without producing missing energy signals at the LHC. Our approach differs from that of Nikolidakis and Smith in that we impose holomorphy on the MFV spurions. The resulting model is highly constrained and R-parity emerges as an accidental approximate symmetry of the low-energy Lagrangian. The size of the small R-parity violating terms is determined by the flavor parameters, and in the absence of neutrino masses there is only one renormalizable R-parity violating interaction: the baryon-number violating $\bar{u}\bar{d}\bar{d}$ superpotential term. Low energy observables (proton decay, dinucleon decay and $n-\bar{n}$ oscillation) pose only mild constraints on the parameter space. LHC phenomenology will depend on whether the LSP is a squark, neutralino, chargino or slepton. If the LSP is a squark it will have prompt decays, explaining the non-observation of events with missing transverse energy at the LHC.
[ { "created": "Fri, 4 Nov 2011 20:00:13 GMT", "version": "v1" }, { "created": "Wed, 21 Dec 2011 20:35:32 GMT", "version": "v2" }, { "created": "Thu, 20 Sep 2012 22:42:28 GMT", "version": "v3" } ]
2015-03-19
[ [ "Csáki", "Csaba", "" ], [ "Grossman", "Yuval", "" ], [ "Heidenreich", "Ben", "" ] ]
We present an alternative approach to low-energy supersymmetry. Instead of imposing R-parity we apply the minimal flavor violation (MFV) hypothesis to the R-parity violating MSSM. In this framework, which we call MFV SUSY, squarks can be light and the proton long lived without producing missing energy signals at the LHC. Our approach differs from that of Nikolidakis and Smith in that we impose holomorphy on the MFV spurions. The resulting model is highly constrained and R-parity emerges as an accidental approximate symmetry of the low-energy Lagrangian. The size of the small R-parity violating terms is determined by the flavor parameters, and in the absence of neutrino masses there is only one renormalizable R-parity violating interaction: the baryon-number violating $\bar{u}\bar{d}\bar{d}$ superpotential term. Low energy observables (proton decay, dinucleon decay and $n-\bar{n}$ oscillation) pose only mild constraints on the parameter space. LHC phenomenology will depend on whether the LSP is a squark, neutralino, chargino or slepton. If the LSP is a squark it will have prompt decays, explaining the non-observation of events with missing transverse energy at the LHC.
1112.5885
Emidio Gabrielli
Emidio Gabrielli, Antonio Racioppi, Martti Raidal
Implications of the effective axial-vector coupling of gluon on top-quark charge asymmetry at the LHC
few small changes in the text, Fig. 2 corrected, same as published version, 12 pages, 9 figures
Phys.Rev. D85 (2012) 074021
10.1103/PhysRevD.85.074021
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study different top quark charge asymmetries and the variation of $t\bar t$ total cross section induced by the effective axial-vector coupling of gluon in the LHC experiments. We show that rapidity cut-dependent asymmetries are more sensitive to the new physics than the independent ones. We also study the dependence of the asymmetries and variations of total $t\bar t$ cross sections on the invariant mass of $t\bar t$ system and show that it would be necessary to measure those quantities as functions of $m_{tt}$ at the LHC. In the context of considered new physics scenario, 7 TeV LHC has enough sensitivity either to confirm the Tevatron top asymmetry anomaly or to rule it out. In the latter case the LHC is able to put stringent constraint on the new physics scale $\Lambda$ in this framework.
[ { "created": "Mon, 26 Dec 2011 19:20:26 GMT", "version": "v1" }, { "created": "Fri, 13 Jul 2012 14:39:02 GMT", "version": "v2" } ]
2012-07-16
[ [ "Gabrielli", "Emidio", "" ], [ "Racioppi", "Antonio", "" ], [ "Raidal", "Martti", "" ] ]
We study different top quark charge asymmetries and the variation of $t\bar t$ total cross section induced by the effective axial-vector coupling of gluon in the LHC experiments. We show that rapidity cut-dependent asymmetries are more sensitive to the new physics than the independent ones. We also study the dependence of the asymmetries and variations of total $t\bar t$ cross sections on the invariant mass of $t\bar t$ system and show that it would be necessary to measure those quantities as functions of $m_{tt}$ at the LHC. In the context of considered new physics scenario, 7 TeV LHC has enough sensitivity either to confirm the Tevatron top asymmetry anomaly or to rule it out. In the latter case the LHC is able to put stringent constraint on the new physics scale $\Lambda$ in this framework.
2210.07131
Roberta Calabrese
Giacomo Cacciapaglia, Antimo Cagnotta, Roberta Calabrese, Francesco Carnevali, Agostino De Iorio, Alberto Orso Maria Iorio, Stefano Morisi, Francesco Sannino
The Radiative Flavor Template at the LHC: Lepton non-universality and g-2
38 pages, 60 figures, 4 tables
Phys.Rev.D 107 (2023) 5, 055033
10.1103/PhysRevD.107.055033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model of Particle Physics and its description of Nature have been recently challenged by a series of precision measurements performed via different accelerator machines. Statistically significant anomalies emerged in the heavy meson physics sector, when measuring the muon magnetic momentum, and very recently when deducing the mass of the W boson. Here we consider a radiative extension of the Standard Model devised to be sufficiently versatile to reconcile the various experimental results while further predicting the existence of new bosons and fermions with a mass spectrum in the TeV energy scale. The resulting spectrum is, therefore, within the energy reach of the proton-proton collisions at the LHC experiments at CERN. The model investigated here allows to interpolate between composite and elementary extensions of the Standard Model with emphasis on a new modified Yukawa sector that is needed to accommodate the anomalies. Focusing on the radiative regime of the model, we introduce interesting search channels of immediate impact for the ATLAS and CMS experimental programs such as the associate production of Standard Model particles with either invisible or long-lived particles. We further show how to adapt earlier SUSY-motivated searchers of new physics to constrain the spectrum and couplings of the new scalars and fermions. Overall, the new physics template simultaneously accounts for the bulk of the observed experimental anomalies while suggesting a wide spectrum of experimental signatures relevant for the current LHC experiments.
[ { "created": "Thu, 13 Oct 2022 16:15:28 GMT", "version": "v1" }, { "created": "Wed, 19 Apr 2023 16:24:35 GMT", "version": "v2" } ]
2023-04-20
[ [ "Cacciapaglia", "Giacomo", "" ], [ "Cagnotta", "Antimo", "" ], [ "Calabrese", "Roberta", "" ], [ "Carnevali", "Francesco", "" ], [ "De Iorio", "Agostino", "" ], [ "Iorio", "Alberto Orso Maria", "" ], [ "Morisi", ...
The Standard Model of Particle Physics and its description of Nature have been recently challenged by a series of precision measurements performed via different accelerator machines. Statistically significant anomalies emerged in the heavy meson physics sector, when measuring the muon magnetic momentum, and very recently when deducing the mass of the W boson. Here we consider a radiative extension of the Standard Model devised to be sufficiently versatile to reconcile the various experimental results while further predicting the existence of new bosons and fermions with a mass spectrum in the TeV energy scale. The resulting spectrum is, therefore, within the energy reach of the proton-proton collisions at the LHC experiments at CERN. The model investigated here allows to interpolate between composite and elementary extensions of the Standard Model with emphasis on a new modified Yukawa sector that is needed to accommodate the anomalies. Focusing on the radiative regime of the model, we introduce interesting search channels of immediate impact for the ATLAS and CMS experimental programs such as the associate production of Standard Model particles with either invisible or long-lived particles. We further show how to adapt earlier SUSY-motivated searchers of new physics to constrain the spectrum and couplings of the new scalars and fermions. Overall, the new physics template simultaneously accounts for the bulk of the observed experimental anomalies while suggesting a wide spectrum of experimental signatures relevant for the current LHC experiments.
2307.02382
Jing Song
Jing Song, L.R.Dai and E.Oset
Evolution of compact states to molecular ones with coupled channels: The case of the $X(3872)$
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the molecular probability of the $X(3872)$ in the $D^0 \bar D^{*0}$ and $D^+ D^{*-}$ channels in several scenarios. One of them assumes that the state is purely due to a genuine nonmolecular component. However, it gets unavoidably dressed by the meson components to the point that in the limit of zero binding of the $D^0 \bar D^{*0}$ component becomes purely molecular. Yet, the small but finite binding allows for a nonmolecular state when the bare mass of the genuine state approaches the $D^0 \bar D^{*0}$ threshold, but, in this case the system develops a small scattering length and a huge effective range for this channel in flagrant disagreement with present values of these magnitudes. Next we discuss the possibility to have hybrid states stemming from the combined effect of a genuine state and a reasonable direct interaction between the meson components, where we find cases in which the scattering length and effective range are still compatible with data, but even then the molecular probability is as big as $95 \%$. Finally, we perform the calculations when the binding stems purely from the direct interaction between the meson-meson components. In summary we conclude, that while present data definitely rule out the possibility of a dominant nonmolecular component, the precise value of the molecular probability requires a more precise determination of the scattering length and effective range of the $D^0 \bar D^{*0}$ channel, as well as the measurement of these magnitudes for the $D^+ D^{*-}$ channel which have not been determined experimentally so far.
[ { "created": "Wed, 5 Jul 2023 15:50:43 GMT", "version": "v1" }, { "created": "Wed, 12 Jul 2023 16:31:58 GMT", "version": "v2" } ]
2023-07-13
[ [ "Song", "Jing", "" ], [ "Dai", "L. R.", "" ], [ "Oset", "E.", "" ] ]
We study the molecular probability of the $X(3872)$ in the $D^0 \bar D^{*0}$ and $D^+ D^{*-}$ channels in several scenarios. One of them assumes that the state is purely due to a genuine nonmolecular component. However, it gets unavoidably dressed by the meson components to the point that in the limit of zero binding of the $D^0 \bar D^{*0}$ component becomes purely molecular. Yet, the small but finite binding allows for a nonmolecular state when the bare mass of the genuine state approaches the $D^0 \bar D^{*0}$ threshold, but, in this case the system develops a small scattering length and a huge effective range for this channel in flagrant disagreement with present values of these magnitudes. Next we discuss the possibility to have hybrid states stemming from the combined effect of a genuine state and a reasonable direct interaction between the meson components, where we find cases in which the scattering length and effective range are still compatible with data, but even then the molecular probability is as big as $95 \%$. Finally, we perform the calculations when the binding stems purely from the direct interaction between the meson-meson components. In summary we conclude, that while present data definitely rule out the possibility of a dominant nonmolecular component, the precise value of the molecular probability requires a more precise determination of the scattering length and effective range of the $D^0 \bar D^{*0}$ channel, as well as the measurement of these magnitudes for the $D^+ D^{*-}$ channel which have not been determined experimentally so far.
hep-ph/0310053
Heinrich P\"as
F. Deppisch, H. P\"as, A. Redelbach, R. R\"uckl, Y. Shimizu
The SUSY seesaw model and lepton-flavor violation at a future electron-positron linear collider
31 pages, 10 figures, version published in Phys. Rev. D
Phys.Rev.D69:054014,2004
10.1103/PhysRevD.69.054014
WUE-ITP-2003-012
hep-ph
null
We study lepton-flavor violating slepton production and decay at a future e^+e^- linear collider in context with the seesaw mechanism in mSUGRA post-LEP benchmark scenarios. The present knowledge in the neutrino sector as well as improved future measurements are taken into account. We calculate the signal cross-sections \sigma(e^{+/-}e^- -> l_{\beta}^{+/-} l_{\alpha}^- \tilde{\chi}_b^0 \tilde{\chi}_a^0); l_{\delta}=e, \mu, \tau; \alpha =|= \beta and estimate the main background processes. Furthermore, we investigate the correlations of these signals with the corresponding lepton-flavor violating rare decays l_{\alpha} -> l_{\beta} \gamma. It is shown that these correlations are relatively weakly affected by uncertainties in the neutrino data, but very sensitive to the model parameters. Hence, they are particularly suited for probing the origin of lepton-flavor violation.
[ { "created": "Fri, 3 Oct 2003 17:39:00 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2003 13:56:55 GMT", "version": "v2" }, { "created": "Tue, 11 May 2004 16:58:54 GMT", "version": "v3" } ]
2008-11-26
[ [ "Deppisch", "F.", "" ], [ "Päs", "H.", "" ], [ "Redelbach", "A.", "" ], [ "Rückl", "R.", "" ], [ "Shimizu", "Y.", "" ] ]
We study lepton-flavor violating slepton production and decay at a future e^+e^- linear collider in context with the seesaw mechanism in mSUGRA post-LEP benchmark scenarios. The present knowledge in the neutrino sector as well as improved future measurements are taken into account. We calculate the signal cross-sections \sigma(e^{+/-}e^- -> l_{\beta}^{+/-} l_{\alpha}^- \tilde{\chi}_b^0 \tilde{\chi}_a^0); l_{\delta}=e, \mu, \tau; \alpha =|= \beta and estimate the main background processes. Furthermore, we investigate the correlations of these signals with the corresponding lepton-flavor violating rare decays l_{\alpha} -> l_{\beta} \gamma. It is shown that these correlations are relatively weakly affected by uncertainties in the neutrino data, but very sensitive to the model parameters. Hence, they are particularly suited for probing the origin of lepton-flavor violation.
hep-ph/0607231
Masafumi Kurachi
Masafumi Kurachi, Robert Shrock
Behavior of the S Parameter in the Crossover Region Between Walking and QCD-Like Regimes of an SU(N) Gauge Theory
14 pages, 4 figures
Phys.Rev.D74:056003,2006
10.1103/PhysRevD.74.056003
YITP-SB-06-32
hep-ph
null
We consider a vectorial, confining SU(N) gauge theory with a variable number, $N_f$, of massless fermions transforming according to the fundamental representation. Using the Schwinger-Dyson and Bethe-Salpeter equations, we calculate the $S$ parameter in terms of the current-current correlation functions. We focus on values of $N_f$ such that the theory is in the crossover region between the regimes of walking behavior and QCD-like (non-walking) behavior. Our calculations indicate that the contribution to $S$ from a given fermion decreases as one moves from the QCD-like to the walking regimes. The implications of this result for technicolor theories are discussed.
[ { "created": "Thu, 20 Jul 2006 18:54:04 GMT", "version": "v1" } ]
2011-07-19
[ [ "Kurachi", "Masafumi", "" ], [ "Shrock", "Robert", "" ] ]
We consider a vectorial, confining SU(N) gauge theory with a variable number, $N_f$, of massless fermions transforming according to the fundamental representation. Using the Schwinger-Dyson and Bethe-Salpeter equations, we calculate the $S$ parameter in terms of the current-current correlation functions. We focus on values of $N_f$ such that the theory is in the crossover region between the regimes of walking behavior and QCD-like (non-walking) behavior. Our calculations indicate that the contribution to $S$ from a given fermion decreases as one moves from the QCD-like to the walking regimes. The implications of this result for technicolor theories are discussed.
2202.04704
Manoranjan Dutta
Manoranjan Dutta (1), Nimmala Narendra (2), Narendra Sahu (1), Sujay Shil (3,4,5) ((1) Indian Institute of Technology Hyderabad, (2) Physical Research Laboratory Ahmedabad, (3) Indian Institute of Technology Gandhinagar, (4) Institute of Physics, Bhubaneswar, (5) Homi Bhabha National Institute, Mumbai)
Asymmetric Self-interacting Dark Matter via Dirac Leptogenesis
17 pages, 10 captioned figures, Version accepted for publication in PRD
null
10.1103/PhysRevD.106.095017
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The nature of neutrinos, whether Dirac or Majorana, is hitherto not known. Assuming that the neutrinos are Dirac, which needs $B-L$ to be an exact symmetry, we make an attempt to explain the observed proportionality between the relic densities of dark matter (DM) and baryonic matter in the present Universe ${\it i.e.,}\,\, \Omega_{\rm DM} \approx 5\, \Omega_{\rm B}$. Assuming the existence of heavy $SU(2)_L$ scalar doublet $(X= (X^0, X^-)^T)$ in the early Universe, an equal and opposite $B-L$ asymmetry can be generated in left and right-handed sectors by the CP-violating out-of-equilibrium decay $X^0 \to \nu_L \nu_R$ since $B-L$ is an exact symmetry. We ensure that $\nu_L-\nu_R$ equilibration does not occur until below the electroweak (EW) phase transition during which a part of the lepton asymmetry gets converted to dark matter asymmetry through a dimension eight operator, which conserves $B-L$ symmetry and is in thermal equilibrium. The remaining $B-L$ asymmetry then gets converted to a net B-asymmetry through EW-sphalerons which are active at a temperature above 100 GeV. To alleviate the small-scale anomalies of $\Lambda$CDM, we assume the DM to be self-interacting via a light mediator, which not only depletes the symmetric component of the DM, but also paves a way to detect the DM at terrestrial laboratories through scalar portal mixing.
[ { "created": "Wed, 9 Feb 2022 19:57:16 GMT", "version": "v1" }, { "created": "Sun, 23 Oct 2022 06:01:03 GMT", "version": "v2" } ]
2022-11-30
[ [ "Dutta", "Manoranjan", "" ], [ "Narendra", "Nimmala", "" ], [ "Sahu", "Narendra", "" ], [ "Shil", "Sujay", "" ] ]
The nature of neutrinos, whether Dirac or Majorana, is hitherto not known. Assuming that the neutrinos are Dirac, which needs $B-L$ to be an exact symmetry, we make an attempt to explain the observed proportionality between the relic densities of dark matter (DM) and baryonic matter in the present Universe ${\it i.e.,}\,\, \Omega_{\rm DM} \approx 5\, \Omega_{\rm B}$. Assuming the existence of heavy $SU(2)_L$ scalar doublet $(X= (X^0, X^-)^T)$ in the early Universe, an equal and opposite $B-L$ asymmetry can be generated in left and right-handed sectors by the CP-violating out-of-equilibrium decay $X^0 \to \nu_L \nu_R$ since $B-L$ is an exact symmetry. We ensure that $\nu_L-\nu_R$ equilibration does not occur until below the electroweak (EW) phase transition during which a part of the lepton asymmetry gets converted to dark matter asymmetry through a dimension eight operator, which conserves $B-L$ symmetry and is in thermal equilibrium. The remaining $B-L$ asymmetry then gets converted to a net B-asymmetry through EW-sphalerons which are active at a temperature above 100 GeV. To alleviate the small-scale anomalies of $\Lambda$CDM, we assume the DM to be self-interacting via a light mediator, which not only depletes the symmetric component of the DM, but also paves a way to detect the DM at terrestrial laboratories through scalar portal mixing.
2007.04400
Mauro Valli
Lina Alasfar, Aleksandr Azatov, Jorge de Blas, Ayan Paul and Mauro Valli
$B$ anomalies under the lens of electroweak precision
35 pages, 9 figures, 1 table. Some references added. Matching published version
null
10.1007/JHEP12(2020)016
DESY 20-091, HU-EP-20/12-RTG, SISSA 16/2020/FISI, UCI-TR 2020-10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The measurements carried out at LEP and SLC projected us into the precision era of electroweak physics. This has also been relevant in the theoretical interpretation of LHCb and Belle measurements of rare $B$ semileptonic decays, paving the road for new physics with the inference of lepton universality violation in $R_{K^{(*)}}$ ratios. The simplest explanation of these flavour anomalies -- sizeable one-loop contributions respecting Minimal Flavour Violation -- is currently disfavoured by electroweak precision data. In this work, we discuss how to completely relieve the present tension between electroweak constraints and one-loop minimal flavour violating solutions to $R_{K^{(*)}}$. We determine the correlations in the Standard Model Effective Field Theory that highlight the existence of such a possibility. Then, we consider minimal extensions of the Standard Model where our effective-field-theory picture can be realized. We discuss how these solutions to $b \to s \ell \ell$ anomalies, respecting electroweak precision and without any new source of flavour violation, may point to the existence of a $Z^{\prime}$ boson at around the TeV scale, within the discovery potential of LHC, or to leptoquark scenarios.
[ { "created": "Wed, 8 Jul 2020 20:02:15 GMT", "version": "v1" }, { "created": "Thu, 4 Feb 2021 09:23:54 GMT", "version": "v2" } ]
2021-02-05
[ [ "Alasfar", "Lina", "" ], [ "Azatov", "Aleksandr", "" ], [ "de Blas", "Jorge", "" ], [ "Paul", "Ayan", "" ], [ "Valli", "Mauro", "" ] ]
The measurements carried out at LEP and SLC projected us into the precision era of electroweak physics. This has also been relevant in the theoretical interpretation of LHCb and Belle measurements of rare $B$ semileptonic decays, paving the road for new physics with the inference of lepton universality violation in $R_{K^{(*)}}$ ratios. The simplest explanation of these flavour anomalies -- sizeable one-loop contributions respecting Minimal Flavour Violation -- is currently disfavoured by electroweak precision data. In this work, we discuss how to completely relieve the present tension between electroweak constraints and one-loop minimal flavour violating solutions to $R_{K^{(*)}}$. We determine the correlations in the Standard Model Effective Field Theory that highlight the existence of such a possibility. Then, we consider minimal extensions of the Standard Model where our effective-field-theory picture can be realized. We discuss how these solutions to $b \to s \ell \ell$ anomalies, respecting electroweak precision and without any new source of flavour violation, may point to the existence of a $Z^{\prime}$ boson at around the TeV scale, within the discovery potential of LHC, or to leptoquark scenarios.
1703.09065
Massimiliano Grazzini
Massimiliano Grazzini, Stefan Kallweit, Dirk Rathlev, Marius Wiesemann
$W^\pm Z$ production at the LHC: fiducial cross sections and distributions in NNLO QCD
38 pages, 18 figures, 8 tables
null
10.1007/JHEP05(2017)139
ZU-TH 06/17, CERN-TH-2017-065
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the first fully differential calculation for $W^\pm Z$ production in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. Leptonic decays of the $W$ and $Z$ bosons are consistently taken into account, i.e. we include all resonant and non-resonant diagrams that contribute to the process $pp\to \ell^{'\pm} \nu_{\ell^{'}} \ell^+\ell^-+X$ both in the same-flavour ($\ell'=\ell$) and the different-flavour ($\ell'\neq \ell$) channel. Fiducial cross sections and distributions are presented in the presence of standard selection cuts applied in the experimental $W^\pm Z$ analyses by ATLAS and CMS at centre-of-mass energies of 8 and 13\,TeV. As previously shown for the inclusive cross section, NNLO corrections increase the NLO result by about $10\%$, thereby leading to an improved agreement with experimental data. The importance of NNLO accurate predictions is also shown in the case of new-physics scenarios, where, especially in high-$p_T$ categories, their impact can reach ${\cal O}(20\%)$. The availability of differential NNLO predictions will play a crucial role in the rich physics programme that is based on precision studies of $W^\pm Z$ signatures at the LHC.
[ { "created": "Mon, 27 Mar 2017 13:37:03 GMT", "version": "v1" } ]
2017-09-13
[ [ "Grazzini", "Massimiliano", "" ], [ "Kallweit", "Stefan", "" ], [ "Rathlev", "Dirk", "" ], [ "Wiesemann", "Marius", "" ] ]
We report on the first fully differential calculation for $W^\pm Z$ production in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. Leptonic decays of the $W$ and $Z$ bosons are consistently taken into account, i.e. we include all resonant and non-resonant diagrams that contribute to the process $pp\to \ell^{'\pm} \nu_{\ell^{'}} \ell^+\ell^-+X$ both in the same-flavour ($\ell'=\ell$) and the different-flavour ($\ell'\neq \ell$) channel. Fiducial cross sections and distributions are presented in the presence of standard selection cuts applied in the experimental $W^\pm Z$ analyses by ATLAS and CMS at centre-of-mass energies of 8 and 13\,TeV. As previously shown for the inclusive cross section, NNLO corrections increase the NLO result by about $10\%$, thereby leading to an improved agreement with experimental data. The importance of NNLO accurate predictions is also shown in the case of new-physics scenarios, where, especially in high-$p_T$ categories, their impact can reach ${\cal O}(20\%)$. The availability of differential NNLO predictions will play a crucial role in the rich physics programme that is based on precision studies of $W^\pm Z$ signatures at the LHC.
hep-ph/9612294
ChangMoh kim
Seung Woo Ham, Sun Kun Oh, and Bjong Ro Kim
Experimental constraints on the parameter space of the next-to-minimal supersymmetric standard model at LEP 2
14 pages (3 figures are included)
Phys.Lett. B414 (1997) 305-314
10.1016/S0370-2693(97)01175-1
KKUCC-96-3
hep-ph
null
We search for the neutral Higgs sector of the next-to-minimal supersymmetric standard model at LEP 2. At the tree level any experimental constraints on $\tan \beta$ cannot be set by the Higgs search at LEP 2 with $\sqrt{s}$ = 175 GeV, whereas at LEP 2 with $\sqrt{s}$ = 192 GeV $\tan \beta$ can be set by an experimental constraint. Furthermore the tree level parameter space of the model can be completely explored by the Higgs search at LEP 2 with $\sqrt{s}$ = 205 GeV. Radiative corrections both to the neutral Higgs boson masses and to the relevant couplings for the scalar Higgs productions give large contributions to the production cross sections of the scalar Higgs bosons at the tree level. The tree level situation at LEP 2 with $\sqrt{s}$ = 192 GeV as well as with $\sqrt{s}$ = 205 GeV can be drastically changed by these effects. We expect that a small region of the 1-loop level parameter space of the model via the scalar Higgs production can be explored by the Higgs search at LEP 2.
[ { "created": "Mon, 9 Dec 1996 05:45:28 GMT", "version": "v1" } ]
2009-10-30
[ [ "Ham", "Seung Woo", "" ], [ "Oh", "Sun Kun", "" ], [ "Kim", "Bjong Ro", "" ] ]
We search for the neutral Higgs sector of the next-to-minimal supersymmetric standard model at LEP 2. At the tree level any experimental constraints on $\tan \beta$ cannot be set by the Higgs search at LEP 2 with $\sqrt{s}$ = 175 GeV, whereas at LEP 2 with $\sqrt{s}$ = 192 GeV $\tan \beta$ can be set by an experimental constraint. Furthermore the tree level parameter space of the model can be completely explored by the Higgs search at LEP 2 with $\sqrt{s}$ = 205 GeV. Radiative corrections both to the neutral Higgs boson masses and to the relevant couplings for the scalar Higgs productions give large contributions to the production cross sections of the scalar Higgs bosons at the tree level. The tree level situation at LEP 2 with $\sqrt{s}$ = 192 GeV as well as with $\sqrt{s}$ = 205 GeV can be drastically changed by these effects. We expect that a small region of the 1-loop level parameter space of the model via the scalar Higgs production can be explored by the Higgs search at LEP 2.
1406.7837
Stefan Liebler
Asma Cheriguene, Stefan Liebler, Werner Porod
CP violation in bilinear R-parity violation and its consequences for the early universe
26 pages, 13 figures
Phys. Rev. D 90, 055012 (2014)
10.1103/PhysRevD.90.055012
DESY 14-109
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetric models with bilinear R-parity violation (BRpV) provide a framework for neutrino masses and mixing angles to explain neutrino oscillation data. We consider CP violation within the new physical phases in BRpV and discuss their effect on the generation of neutrino masses and the decays of the lightest supersymmetric particle (LSP), being a light neutralino with mass $\sim 100$ GeV, at next-to-leading order. The decays affect the lepton and via sphaleron transitions the baryon asymmetry in the early universe. For a rather light LSP, asymmetries generated before the electroweak phase transition via e.g. the Affleck-Dine mechanism are reduced up to two orders of magnitude, but are still present. On the other hand, the decays of a light LSP themselves can account for the generation of a lepton and baryon asymmetry, the latter in accordance to the observation in our universe, since the smallness of the BRpV parameters allows for an out-of-equilibrium decay and sufficiently large CP violation is possible consistent with experimental bounds from the non-observation of electric dipole-moments.
[ { "created": "Mon, 30 Jun 2014 18:10:54 GMT", "version": "v1" } ]
2014-09-17
[ [ "Cheriguene", "Asma", "" ], [ "Liebler", "Stefan", "" ], [ "Porod", "Werner", "" ] ]
Supersymmetric models with bilinear R-parity violation (BRpV) provide a framework for neutrino masses and mixing angles to explain neutrino oscillation data. We consider CP violation within the new physical phases in BRpV and discuss their effect on the generation of neutrino masses and the decays of the lightest supersymmetric particle (LSP), being a light neutralino with mass $\sim 100$ GeV, at next-to-leading order. The decays affect the lepton and via sphaleron transitions the baryon asymmetry in the early universe. For a rather light LSP, asymmetries generated before the electroweak phase transition via e.g. the Affleck-Dine mechanism are reduced up to two orders of magnitude, but are still present. On the other hand, the decays of a light LSP themselves can account for the generation of a lepton and baryon asymmetry, the latter in accordance to the observation in our universe, since the smallness of the BRpV parameters allows for an out-of-equilibrium decay and sufficiently large CP violation is possible consistent with experimental bounds from the non-observation of electric dipole-moments.
0805.2291
B. L. G. Bakker
A. M. Badalian, B. L. G. Bakker, I. V. Danilkin
The $\mathbf{S}-\mathbf{D}$ mixing and di-electron widths of higher charmonium $\mathbf{1^{--}}$ states
19 pages, no figures
Phys.Atom.Nucl.72:638-646,2009
10.1134/S1063778809040085
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The di-electron widths of $\psi(4040)$, $\psi(4160)$, and $\psi(4415)$, and their ratios are shown to be in good agreement with experiment, if in all cases the $S-D$ mixing with a large mixing angle $\theta\approx 34^\circ$ is taken. Arguments are presented why continuum states give small contributions to the wave functions at the origin. We find that the Y(4360) resonance, considered as a pure $3 {}^3D_1$ state, would have very small di-electron width, $\Gamma_{ee}(Y(4360))=0.060$ keV. On the contrary, for large mixing between the $4 {}^3S_1$ and $3 {}^3D_1$ states with the mixing angle $\theta=34.8^\circ$, $\Gamma_{ee}(\psi(4415))=0.57$ keV coincides with the experimental number, while a second physical resonance, probably Y(4360), has also a rather large $\Gamma_{ee} (Y(\sim 4400))=0.61$ keV. For the higher resonance Y(4660), considered as a pure $5 {}^3S_1$ state, we predict the di-electron width $\Gamma_{ee}(Y(4660))=0.70$ keV, but it becomes significantly smaller, namely 0.31 keV, if the mixing angle between the $5 {}^3S_1$ and $4 {}^3D_1$ states $\theta=34^\circ$. The mass and di-electron width of the $6 {}^3S_1$ charmonium state are calculated.
[ { "created": "Thu, 15 May 2008 12:57:42 GMT", "version": "v1" }, { "created": "Mon, 2 Feb 2009 09:27:48 GMT", "version": "v2" } ]
2009-05-12
[ [ "Badalian", "A. M.", "" ], [ "Bakker", "B. L. G.", "" ], [ "Danilkin", "I. V.", "" ] ]
The di-electron widths of $\psi(4040)$, $\psi(4160)$, and $\psi(4415)$, and their ratios are shown to be in good agreement with experiment, if in all cases the $S-D$ mixing with a large mixing angle $\theta\approx 34^\circ$ is taken. Arguments are presented why continuum states give small contributions to the wave functions at the origin. We find that the Y(4360) resonance, considered as a pure $3 {}^3D_1$ state, would have very small di-electron width, $\Gamma_{ee}(Y(4360))=0.060$ keV. On the contrary, for large mixing between the $4 {}^3S_1$ and $3 {}^3D_1$ states with the mixing angle $\theta=34.8^\circ$, $\Gamma_{ee}(\psi(4415))=0.57$ keV coincides with the experimental number, while a second physical resonance, probably Y(4360), has also a rather large $\Gamma_{ee} (Y(\sim 4400))=0.61$ keV. For the higher resonance Y(4660), considered as a pure $5 {}^3S_1$ state, we predict the di-electron width $\Gamma_{ee}(Y(4660))=0.70$ keV, but it becomes significantly smaller, namely 0.31 keV, if the mixing angle between the $5 {}^3S_1$ and $4 {}^3D_1$ states $\theta=34^\circ$. The mass and di-electron width of the $6 {}^3S_1$ charmonium state are calculated.
2312.12799
N Furey
N. Furey
An Algebraic Roadmap of Particle Theories, Part II: Theoretical checkpoints
6 pages, 1 figure, Second paper in a series. Follows arXiv:2312.12377
null
null
HU-EP-23/65
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
An optimal algebraic model of particle physics has a number of checkpoints to pass. As a minimum, models should $\langle 1 \rangle$ conform to the Coleman-Mandula theorem (or establish a loophole), $\langle 2 \rangle$ evade familiar fermion doubling problems, $\langle 3 \rangle$ naturally explain the Standard Model's chirality, $\langle 4 \rangle$ exclude B-L gauge symmetry at low energy, and $\langle 5 \rangle$ explain the existence of three generations. We demonstrate how the model introduced in [1] passes checkpoints $\langle 1 \rangle, \langle 2 \rangle, \langle 3 \rangle, \langle 4 \rangle$, and has yet to cross $\langle 5 \rangle$. We close by elucidating an unexpected appearance of spacetime symmetries.
[ { "created": "Wed, 20 Dec 2023 06:40:31 GMT", "version": "v1" } ]
2023-12-21
[ [ "Furey", "N.", "" ] ]
An optimal algebraic model of particle physics has a number of checkpoints to pass. As a minimum, models should $\langle 1 \rangle$ conform to the Coleman-Mandula theorem (or establish a loophole), $\langle 2 \rangle$ evade familiar fermion doubling problems, $\langle 3 \rangle$ naturally explain the Standard Model's chirality, $\langle 4 \rangle$ exclude B-L gauge symmetry at low energy, and $\langle 5 \rangle$ explain the existence of three generations. We demonstrate how the model introduced in [1] passes checkpoints $\langle 1 \rangle, \langle 2 \rangle, \langle 3 \rangle, \langle 4 \rangle$, and has yet to cross $\langle 5 \rangle$. We close by elucidating an unexpected appearance of spacetime symmetries.