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hep-ph/0208183
Andrei Afanasev
A. Afanasev, I. Akushevich, V. Burkert, K. Joo
QED Radiative Corrections in Processes of Exclusive Pion Electroproduction
13 pages, 9 figures; requires RevTeX 4
Phys.Rev. D66 (2002) 074004
10.1103/PhysRevD.66.074004
null
hep-ph nucl-ex nucl-th
null
Formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.
[ { "created": "Tue, 20 Aug 2002 18:11:20 GMT", "version": "v1" } ]
2009-11-07
[ [ "Afanasev", "A.", "" ], [ "Akushevich", "I.", "" ], [ "Burkert", "V.", "" ], [ "Joo", "K.", "" ] ]
Formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.
1206.0157
Robert Harlander
Robert V. Harlander, Tobias Neumann, Kemal J. Ozeren, Marius Wiesemann
Top-mass effects in differential Higgs production through gluon fusion at order \alpha_s^4
21 pages, 12 figures
JHEP 1208 (2012) 139
10.1007/JHEP08(2012)139
CERN-PH-TH/2012-146; LPN12-053; UCLA/12/TEP/101; WUB/12-13
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effects from a finite top quark mass on differential distributions in the Higgs+jet production cross section through gluon fusion are studied at next-to-leading order in the strong coupling, i.e. $O(\alpha_s^4)$. Terms formally subleading in $1/m_t$ are calculated, and their influence on the transverse momentum and rapidity distribution of the Higgs boson are evaluated. We find that, for the differential K-factor, the heavy-top limit is valid at the 2-3% level as long as the transverse momentum of the Higgs remains below about 150 GeV.
[ { "created": "Fri, 1 Jun 2012 11:46:42 GMT", "version": "v1" } ]
2013-08-13
[ [ "Harlander", "Robert V.", "" ], [ "Neumann", "Tobias", "" ], [ "Ozeren", "Kemal J.", "" ], [ "Wiesemann", "Marius", "" ] ]
Effects from a finite top quark mass on differential distributions in the Higgs+jet production cross section through gluon fusion are studied at next-to-leading order in the strong coupling, i.e. $O(\alpha_s^4)$. Terms formally subleading in $1/m_t$ are calculated, and their influence on the transverse momentum and rapidity distribution of the Higgs boson are evaluated. We find that, for the differential K-factor, the heavy-top limit is valid at the 2-3% level as long as the transverse momentum of the Higgs remains below about 150 GeV.
hep-ph/9806464
Alfonso Leyva
S. Groote, J.G. K\"orner and J.A. Leyva
Gluon Polarization in e^+e^- -> t \bar t G: Polar Angle Dependence and Beam Polarization Effects
19 pages, 9 postscript figures, to appear in Eur. Phys. J. C
Eur.Phys.J.C7:49-59,1999
10.1007/s100529800981
MZ-TH/97-17
hep-ph
null
We calculate the linear and circular polarization of gluons produced in conjunction with massive quarks in the annihilation process $e^+e^-\to q \bar q G$. The linear polarization is calculated in the hadron event plane as well as in the gluon-beam plane. Beam polarization and polar orientation effects are included in our discussion. For typical top pair production energies at the Next-Linear-Collider (NLC) the degree of linear polarization in the hadron event plane remains close to its soft gluon value of 100% over most of the energy spectrum of the gluon. The linear polarization in the gluon-beam plane is generally smaller but peaks toward the hard end of the gluon spectrum. The dependence of the linear polarization on beam polarization and on the polar orientation of the gluon is small. The circular polarization is largest for maximal gluon energies and shows a strong dependence on the longitudinal beam polarization. The longitudinal polarization of the beam may therefore be used to tune the circular polarization of the gluon. The massive quark results are compared with the corresponding results for the massless quark case.
[ { "created": "Wed, 24 Jun 1998 12:45:52 GMT", "version": "v1" }, { "created": "Thu, 9 Jul 1998 12:13:19 GMT", "version": "v2" } ]
2011-09-13
[ [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Leyva", "J. A.", "" ] ]
We calculate the linear and circular polarization of gluons produced in conjunction with massive quarks in the annihilation process $e^+e^-\to q \bar q G$. The linear polarization is calculated in the hadron event plane as well as in the gluon-beam plane. Beam polarization and polar orientation effects are included in our discussion. For typical top pair production energies at the Next-Linear-Collider (NLC) the degree of linear polarization in the hadron event plane remains close to its soft gluon value of 100% over most of the energy spectrum of the gluon. The linear polarization in the gluon-beam plane is generally smaller but peaks toward the hard end of the gluon spectrum. The dependence of the linear polarization on beam polarization and on the polar orientation of the gluon is small. The circular polarization is largest for maximal gluon energies and shows a strong dependence on the longitudinal beam polarization. The longitudinal polarization of the beam may therefore be used to tune the circular polarization of the gluon. The massive quark results are compared with the corresponding results for the massless quark case.
1609.02025
Daniel Gomez Dumm
V.P. Pagura, D. Gomez Dumm, S. Noguera, N.N. Scoccola
Magnetic catalysis and inverse magnetic catalysis in nonlocal chiral quark models
14 pages, 3 figures. References added, Fig. 3 enlarged including new results. To be published in Physical Review D
Phys. Rev. D 95, 034013 (2017)
10.1103/PhysRevD.95.034013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the behavior of strongly interacting matter under an external constant magnetic field in the context of nonlocal chiral quark models within the mean field approximation. We find that at zero temperature the behavior of the quark condensates shows the expected magnetic catalysis effect, our predictions being in good quantitative agreement with lattice QCD results. On the other hand, in contrast to what happens in the standard local Nambu-Jona-Lasinio model, when the analysis is extended to the case of finite temperature our results show that nonlocal models naturally lead to the Inverse Magnetic Catalysis effect.
[ { "created": "Wed, 7 Sep 2016 15:43:43 GMT", "version": "v1" }, { "created": "Fri, 3 Feb 2017 14:44:39 GMT", "version": "v2" } ]
2017-02-22
[ [ "Pagura", "V. P.", "" ], [ "Dumm", "D. Gomez", "" ], [ "Noguera", "S.", "" ], [ "Scoccola", "N. N.", "" ] ]
We study the behavior of strongly interacting matter under an external constant magnetic field in the context of nonlocal chiral quark models within the mean field approximation. We find that at zero temperature the behavior of the quark condensates shows the expected magnetic catalysis effect, our predictions being in good quantitative agreement with lattice QCD results. On the other hand, in contrast to what happens in the standard local Nambu-Jona-Lasinio model, when the analysis is extended to the case of finite temperature our results show that nonlocal models naturally lead to the Inverse Magnetic Catalysis effect.
hep-ph/0001131
Carlo Carloni
C.M. Carloni Calame, C. Lunardini, G. Montagna, O. Nicrosini, F. Piccinini
Large-angle Bhabha scattering and luminosity at Daphne
8 pages, LaTeX, 4 eps figures. Contribution to the proceedings of the Workshop on Physics and Detectors for DAPHNE, Frascati, November 16-19, 1999
null
null
FNT/T 99/19
hep-ph
null
The accurate knowledge of luminosity at e^+ e^- flavour factories requires the precision calculation of the Bhabha cross section at large scattering angles. In order to achieve a theoretical accuracy at the 0.1% level, the relevant effect of QED radiative corrections is taken into account in the framework of the Parton Shower method, which allows exclusive event generation. On this scheme, a Monte Carlo event generator (BABAYAGA) is developed for data analysis. To test the reliability of the approach, a benchmark calculation, including exact O(alpha) corrections and higher-order leading logarithmic contributions, is developed as well, implemented in a Monte Carlo integrator (LABSPV) and compared in detail with the BABAYAGA predictions. The effect of initial-state and final-state radiation, O(alpha) next-to-leading and higher-order leading corrections is investigated and discussed in the presence of realistic event selections. The theoretical precision of BABAYAGA is estimated to be at the 0.5% level.
[ { "created": "Fri, 14 Jan 2000 14:28:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Calame", "C. M. Carloni", "" ], [ "Lunardini", "C.", "" ], [ "Montagna", "G.", "" ], [ "Nicrosini", "O.", "" ], [ "Piccinini", "F.", "" ] ]
The accurate knowledge of luminosity at e^+ e^- flavour factories requires the precision calculation of the Bhabha cross section at large scattering angles. In order to achieve a theoretical accuracy at the 0.1% level, the relevant effect of QED radiative corrections is taken into account in the framework of the Parton Shower method, which allows exclusive event generation. On this scheme, a Monte Carlo event generator (BABAYAGA) is developed for data analysis. To test the reliability of the approach, a benchmark calculation, including exact O(alpha) corrections and higher-order leading logarithmic contributions, is developed as well, implemented in a Monte Carlo integrator (LABSPV) and compared in detail with the BABAYAGA predictions. The effect of initial-state and final-state radiation, O(alpha) next-to-leading and higher-order leading corrections is investigated and discussed in the presence of realistic event selections. The theoretical precision of BABAYAGA is estimated to be at the 0.5% level.
1902.07180
Kaustuv Datta
Kaustuv Datta, Andrew Larkoski, Benjamin Nachman
Automating the Construction of Jet Observables with Machine Learning
15 pages, 8 tables, 12 figures
Phys. Rev. D 100, 095016 (2019)
10.1103/PhysRevD.100.095016
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Machine-learning assisted jet substructure tagging techniques have the potential to significantly improve searches for new particles and Standard Model measurements in hadronic final states. Techniques with simple analytic forms are particularly useful for establishing robustness and gaining physical insight. We introduce a procedure to automate the construction of a large class of observables that are chosen to completely specify $M$-body phase space. The procedure is validated on the task of distinguishing $H\rightarrow b\bar{b}$ from $g\rightarrow b\bar{b}$, where $M=3$ and previous brute-force approaches to construct an optimal product observable for the $M$-body phase space have established the baseline performance. We then use the new method to design tailored observables for the boosted $Z'$ search, where $M=4$ and brute-force methods are intractable. The new classifiers outperform standard $2$-prong tagging observables, illustrating the power of the new optimization method for improving searches and measurement at the LHC and beyond.
[ { "created": "Tue, 19 Feb 2019 18:24:36 GMT", "version": "v1" }, { "created": "Tue, 5 Mar 2019 17:01:07 GMT", "version": "v2" } ]
2019-11-20
[ [ "Datta", "Kaustuv", "" ], [ "Larkoski", "Andrew", "" ], [ "Nachman", "Benjamin", "" ] ]
Machine-learning assisted jet substructure tagging techniques have the potential to significantly improve searches for new particles and Standard Model measurements in hadronic final states. Techniques with simple analytic forms are particularly useful for establishing robustness and gaining physical insight. We introduce a procedure to automate the construction of a large class of observables that are chosen to completely specify $M$-body phase space. The procedure is validated on the task of distinguishing $H\rightarrow b\bar{b}$ from $g\rightarrow b\bar{b}$, where $M=3$ and previous brute-force approaches to construct an optimal product observable for the $M$-body phase space have established the baseline performance. We then use the new method to design tailored observables for the boosted $Z'$ search, where $M=4$ and brute-force methods are intractable. The new classifiers outperform standard $2$-prong tagging observables, illustrating the power of the new optimization method for improving searches and measurement at the LHC and beyond.
hep-ph/0605222
Aude Gehrmann
A. Gehrmann-De Ridder
Production of Isolated Photons in Deep Inelastic Scattering
4 pages, 2 figures, talk given at the XLIst Rencontres de Moriond QCD and High Energy Hadronic Interactions, La Thuile, Aosta Valley, Italy, March 18--25, 2006
null
null
null
hep-ph
null
We present here the predictions obtained from a calculation of the inclusive isolated photon production cross section in deep inelastic scattering. The results are compared with the cross section measurement of the ZEUS collaboration and found in good agreement with all aspects of it. Furthermore, a way of measuring the quark-to-photon fragmention function in DIS is also briefly outlined.
[ { "created": "Sat, 20 May 2006 20:42:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ridder", "A. Gehrmann-De", "" ] ]
We present here the predictions obtained from a calculation of the inclusive isolated photon production cross section in deep inelastic scattering. The results are compared with the cross section measurement of the ZEUS collaboration and found in good agreement with all aspects of it. Furthermore, a way of measuring the quark-to-photon fragmention function in DIS is also briefly outlined.
1405.3058
Kazem Azizi
K. Azizi, N. Er, H. Sundu
More about the $B$ and $D$ mesons in nuclear matter
16 Pages, 4 Figures and 3 Tables
null
10.1140/epjc/s10052-014-3021-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the shifts in decay constants of the pseudoscalar $B$ and $D$ mesons in nuclear medium in the frame work of QCD sum rules. We write those shifts in terms of the $B-N$ and $D-N$ scattering lengths and an extra phenomenological parameter entered to calculations. Computing an appreciate forward scattering correlation function, we derive the QCD sum rules for the $B-N$ and $D-N$ scattering lengths and the extra phenomenological parameter in terms of various operators in nuclear medium. We numerically find the values of the shifts in the decay constants compared to their vacuum values. Using the sum rules obtained, we also determine the shifts in the masses of these particles due to nuclear matter and compare the results obtained with the previous predictions in the literature.
[ { "created": "Tue, 13 May 2014 07:58:11 GMT", "version": "v1" }, { "created": "Tue, 5 Aug 2014 04:44:16 GMT", "version": "v2" } ]
2015-06-19
[ [ "Azizi", "K.", "" ], [ "Er", "N.", "" ], [ "Sundu", "H.", "" ] ]
We calculate the shifts in decay constants of the pseudoscalar $B$ and $D$ mesons in nuclear medium in the frame work of QCD sum rules. We write those shifts in terms of the $B-N$ and $D-N$ scattering lengths and an extra phenomenological parameter entered to calculations. Computing an appreciate forward scattering correlation function, we derive the QCD sum rules for the $B-N$ and $D-N$ scattering lengths and the extra phenomenological parameter in terms of various operators in nuclear medium. We numerically find the values of the shifts in the decay constants compared to their vacuum values. Using the sum rules obtained, we also determine the shifts in the masses of these particles due to nuclear matter and compare the results obtained with the previous predictions in the literature.
2304.06078
Adriano Lana Cherchiglia
G. H. S. Alves, A. L. Cherchiglia, C. C. Nishi
Explicit parametrization of more than one vector-like quark of Nelson-Barr type
null
null
10.1103/PhysRevD.108.035049
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Nelson-Barr models solve the strong CP problem based on spontaneous CP violation and generically requires vector-like quarks (VLQs) mixing with standard quarks to transmit the CP violation. We devise an explicit parametrization for the case of two VLQs of either down-type or up-type and quantitatively study several aspects including the hierarchy of the VLQ Yukawas and their irreducible contribution to $\bar{\theta}$. In particular, with the use of the parametrization, we show that a big portion of the parameter space for two up-type VLQs at the TeV scale is still allowed by the constraint on $\bar{\theta}$, although this case had been previously shown to be very restricted based on estimates.
[ { "created": "Wed, 12 Apr 2023 18:00:05 GMT", "version": "v1" } ]
2023-09-01
[ [ "Alves", "G. H. S.", "" ], [ "Cherchiglia", "A. L.", "" ], [ "Nishi", "C. C.", "" ] ]
Nelson-Barr models solve the strong CP problem based on spontaneous CP violation and generically requires vector-like quarks (VLQs) mixing with standard quarks to transmit the CP violation. We devise an explicit parametrization for the case of two VLQs of either down-type or up-type and quantitatively study several aspects including the hierarchy of the VLQ Yukawas and their irreducible contribution to $\bar{\theta}$. In particular, with the use of the parametrization, we show that a big portion of the parameter space for two up-type VLQs at the TeV scale is still allowed by the constraint on $\bar{\theta}$, although this case had been previously shown to be very restricted based on estimates.
1005.1468
Koichi Kanazawa
Koichi Kanazawa and Yuji Koike
New Analysis of the Single Transverse-Spin Asymmetry for Hadron Production at RHIC
16 pages, 6 figures; The figures and the table were changed by correcting the errors in the numerical calculation. Qualitative features stay the same and thus no changes in the text compared with the previous version
Phys.Rev.D82:034009,2010
10.1103/PhysRevD.82.034009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the single transverse-spin asymmetry (SSAs) for inclusive hadron production in the $pp$ collision at RHIC based on the twist-3 mechanism in QCD. As an origin of SSAs, we take into account of all kinds of pole contributions associated with the twist-3 quark-gluon correlation functions in the polarized proton. By the inclusion of the soft-fermion-pole contribution in addition to the soft-gluon-pole contribution, we find SSAs observed at RHIC are better described for all kinds of mesons. $P_T$-dependence of the asymmetry and the comparison with the FNAL data are also presented.
[ { "created": "Mon, 10 May 2010 08:13:03 GMT", "version": "v1" }, { "created": "Thu, 17 Jun 2010 10:29:58 GMT", "version": "v2" }, { "created": "Thu, 15 Jul 2010 03:52:02 GMT", "version": "v3" } ]
2014-11-21
[ [ "Kanazawa", "Koichi", "" ], [ "Koike", "Yuji", "" ] ]
We analyze the single transverse-spin asymmetry (SSAs) for inclusive hadron production in the $pp$ collision at RHIC based on the twist-3 mechanism in QCD. As an origin of SSAs, we take into account of all kinds of pole contributions associated with the twist-3 quark-gluon correlation functions in the polarized proton. By the inclusion of the soft-fermion-pole contribution in addition to the soft-gluon-pole contribution, we find SSAs observed at RHIC are better described for all kinds of mesons. $P_T$-dependence of the asymmetry and the comparison with the FNAL data are also presented.
1411.3325
Anson Hook
Anson Hook
Anomalous solutions to the strong CP problem
4 pages, v2. added a discussion regarding the prefactor for higher dimensional operators
Phys. Rev. Lett. 114, 141801 (2015)
10.1103/PhysRevLett.114.141801
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new mechanism for solving the strong CP problem using a Z2 discrete symmetry and an anomalous U(1) symmetry. A Z2 symmetry is used so that two gauge groups have the same theta angle. An anomalous U(1) symmetry makes the difference between the two theta angles physical and the sum unphysical. Two models are presented where the anomalous symmetry manifests itself in the IR in different ways. In the first model there are massless bifundamental quarks, a solution reminiscent of the massless up quark solution. In the IR of this model, the $\eta'$ boson relaxes the QCD theta angle to the difference between the two theta angles - in this case zero. In the second model, the anomalous U(1) symmetry is realized in the IR as a dynamically generated mass term that has exactly the phase needed to cancel the theta angle. Both of these models make the extremely concrete prediction that there exist new colored particles at the TeV scale.
[ { "created": "Wed, 12 Nov 2014 21:00:03 GMT", "version": "v1" }, { "created": "Fri, 16 Jan 2015 19:48:35 GMT", "version": "v2" } ]
2015-04-16
[ [ "Hook", "Anson", "" ] ]
We present a new mechanism for solving the strong CP problem using a Z2 discrete symmetry and an anomalous U(1) symmetry. A Z2 symmetry is used so that two gauge groups have the same theta angle. An anomalous U(1) symmetry makes the difference between the two theta angles physical and the sum unphysical. Two models are presented where the anomalous symmetry manifests itself in the IR in different ways. In the first model there are massless bifundamental quarks, a solution reminiscent of the massless up quark solution. In the IR of this model, the $\eta'$ boson relaxes the QCD theta angle to the difference between the two theta angles - in this case zero. In the second model, the anomalous U(1) symmetry is realized in the IR as a dynamically generated mass term that has exactly the phase needed to cancel the theta angle. Both of these models make the extremely concrete prediction that there exist new colored particles at the TeV scale.
hep-ph/9506360
null
Konstantin Goulianos
Results on Hard Diffractive Production
Presented at the 10th Topical Workshop on Proton-Antiproton Collider Physics, 9-13 May 1995 10 pages latex using psfig macro with 6 uu-encoded EPS figures. Please send Comments to DINO@rock02.rockefeller.edu
AIP Conf.Proc.357:673-684,1996
10.1063/1.49666
RU-95/E-30
hep-ph
null
The results of experiments at hadron colliders probing the structure of the pomeron through hard diffraction are reviewed. Some results on deep inelastic diffractive scattering obtained at HERA are also discussed and placed in perspective. By using a properly normalized pomeron flux factor in single diffraction dissociation, as dictated by unitarity, the pomeron emerges as a combination of valence quark and gluon color singlets in a ratio suggested by asymptopia.
[ { "created": "Mon, 19 Jun 1995 15:40:53 GMT", "version": "v1" } ]
2014-11-17
[ [ "Goulianos", "Konstantin", "" ] ]
The results of experiments at hadron colliders probing the structure of the pomeron through hard diffraction are reviewed. Some results on deep inelastic diffractive scattering obtained at HERA are also discussed and placed in perspective. By using a properly normalized pomeron flux factor in single diffraction dissociation, as dictated by unitarity, the pomeron emerges as a combination of valence quark and gluon color singlets in a ratio suggested by asymptopia.
1410.6940
Satoshi Mishima
Marco Ciuchini, Enrico Franco, Satoshi Mishima, Maurizio Pierini, Laura Reina, Luca Silvestrini
Update of the electroweak precision fit, interplay with Higgs-boson signal strengths and model-independent constraints on new physics
7 pages, 9 figures. Proceedings of the 37th International Conference on High Energy Physics (ICHEP2014), Valencia, Spain, 2-9 July 2014. v2: a reference added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present updated global fits of the Standard Model and beyond to electroweak precision data, taking into account recent progress in theoretical calculations and experimental measurements. From the fits, we derive model-independent constraints on new physics by introducing oblique and epsilon parameters, and modified $Zb\bar{b}$ and $HVV$ couplings. Furthermore, we also perform fits of the scale factors of the Higgs-boson couplings to observed signal strengths of the Higgs boson.
[ { "created": "Sat, 25 Oct 2014 17:35:58 GMT", "version": "v1" }, { "created": "Wed, 26 Nov 2014 16:29:51 GMT", "version": "v2" } ]
2014-11-27
[ [ "Ciuchini", "Marco", "" ], [ "Franco", "Enrico", "" ], [ "Mishima", "Satoshi", "" ], [ "Pierini", "Maurizio", "" ], [ "Reina", "Laura", "" ], [ "Silvestrini", "Luca", "" ] ]
We present updated global fits of the Standard Model and beyond to electroweak precision data, taking into account recent progress in theoretical calculations and experimental measurements. From the fits, we derive model-independent constraints on new physics by introducing oblique and epsilon parameters, and modified $Zb\bar{b}$ and $HVV$ couplings. Furthermore, we also perform fits of the scale factors of the Higgs-boson couplings to observed signal strengths of the Higgs boson.
1503.01464
Jaime Hern\'andez-S\'anchez Dr.
S. P. Das, J. Hern\'andez-S\'anchez, S. Moretti, A. Rosado and R. Xoxocotzi
Flavor violating signatures of lighter and heavier Higgs bosons within the Two Higgs Doublet Model Type-III at the LHeC
20 pages, 10 figures. We have added an author in the work. We have substantially improved the scan of the parameters space of the model and our results are more optimistic than those presented previously
Phys. Rev. D 94, 055003 (2016)
10.1103/PhysRevD.94.055003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the prospects for observing the CP-even neutral Higgs bosons (h and H) in their decays into flavor violating $b \bar s+ c.c.$ channels at the proposed LHeC, with $\sqrt s \approx 1.3$ TeV, in the 2HDM Type-III, assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We consider theoretically consistent scenarios in agreement with current experimental data from flavor and Higgs physics. We investigate the charged current production process $\nu_e \phi q$ in presence of flavor violating decays of the Higgs bosons, that lead to a 3-jets + $E\!\!\!\!/_T$ signature. We demand exactly two jets, one tagged $b$-jet and one light-flavor jet, all in the central rapidity region. The remaining jet (originated by the remanent quark $q$) is tagged in the forward or backward regions and this together with a central jet veto (not more than one light-flavor jet) are essential criterions to enhance the signal--to--background rates. We consider the most relevant Standard Model (SM) backgrounds, treating $c$-jets separately from light-flavor and gluon ones, while allowing for mis-tagging. We find that the SM-like Higgs boson, $h$, would be accessible within several parameter configurations of our model at approximately the 1-2$\sigma$ level with 100 fb$^{-1}$ of data. We also find that the heaviest neutral Higgs boson, $H$, with mass up to 150 GeV, would have a 1$\sigma$ significance for the same data sample. At the end of the LHeC running, one would have ten times data accumulation and for all the Higgs masses the significances are enhanced so as to allow for detection of both the $h$ and $H$ state. Hence, one of the most viable extensions of 2HDMs with FCNC's generated at tree level but controlled by a four-zero texture approach in the Yukawa matrices, as opposed to the adoption of ad hoc discrete symmetries, could be put under scrutiny at a future LHeC.
[ { "created": "Wed, 4 Mar 2015 21:00:11 GMT", "version": "v1" }, { "created": "Fri, 6 May 2016 18:36:11 GMT", "version": "v2" } ]
2016-09-14
[ [ "Das", "S. P.", "" ], [ "Hernández-Sánchez", "J.", "" ], [ "Moretti", "S.", "" ], [ "Rosado", "A.", "" ], [ "Xoxocotzi", "R.", "" ] ]
We analyze the prospects for observing the CP-even neutral Higgs bosons (h and H) in their decays into flavor violating $b \bar s+ c.c.$ channels at the proposed LHeC, with $\sqrt s \approx 1.3$ TeV, in the 2HDM Type-III, assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We consider theoretically consistent scenarios in agreement with current experimental data from flavor and Higgs physics. We investigate the charged current production process $\nu_e \phi q$ in presence of flavor violating decays of the Higgs bosons, that lead to a 3-jets + $E\!\!\!\!/_T$ signature. We demand exactly two jets, one tagged $b$-jet and one light-flavor jet, all in the central rapidity region. The remaining jet (originated by the remanent quark $q$) is tagged in the forward or backward regions and this together with a central jet veto (not more than one light-flavor jet) are essential criterions to enhance the signal--to--background rates. We consider the most relevant Standard Model (SM) backgrounds, treating $c$-jets separately from light-flavor and gluon ones, while allowing for mis-tagging. We find that the SM-like Higgs boson, $h$, would be accessible within several parameter configurations of our model at approximately the 1-2$\sigma$ level with 100 fb$^{-1}$ of data. We also find that the heaviest neutral Higgs boson, $H$, with mass up to 150 GeV, would have a 1$\sigma$ significance for the same data sample. At the end of the LHeC running, one would have ten times data accumulation and for all the Higgs masses the significances are enhanced so as to allow for detection of both the $h$ and $H$ state. Hence, one of the most viable extensions of 2HDMs with FCNC's generated at tree level but controlled by a four-zero texture approach in the Yukawa matrices, as opposed to the adoption of ad hoc discrete symmetries, could be put under scrutiny at a future LHeC.
2306.08362
Hao-Lei Chen
Hao-Lei Chen, Zhi-Bin Zhu, Xu-Guang Huang
Quark-meson model under rotation: A functional renormalization group study
14 pages, 12 figures
null
10.1103/PhysRevD.108.054006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Rapid rotation may exist in physical systems such as non-central heavy ion collisions and neutron stars. Using functional renormalization group analysis of the quark-meson model, we investigate the effects of real and imaginary rotation on the chiral phase transition. Our results confirm previous studies conducted with other model calculations and shed light on the importance of boundary conditions in the infrared region of the theory.
[ { "created": "Wed, 14 Jun 2023 08:52:15 GMT", "version": "v1" }, { "created": "Fri, 16 Jun 2023 02:27:44 GMT", "version": "v2" }, { "created": "Thu, 6 Jul 2023 05:58:13 GMT", "version": "v3" } ]
2024-03-01
[ [ "Chen", "Hao-Lei", "" ], [ "Zhu", "Zhi-Bin", "" ], [ "Huang", "Xu-Guang", "" ] ]
Rapid rotation may exist in physical systems such as non-central heavy ion collisions and neutron stars. Using functional renormalization group analysis of the quark-meson model, we investigate the effects of real and imaginary rotation on the chiral phase transition. Our results confirm previous studies conducted with other model calculations and shed light on the importance of boundary conditions in the infrared region of the theory.
1008.4710
Christian Speckner
Thorsten Ohl (W\"urzburg University), Christian Speckner (Freiburg University)
The Noncommutative Standard Model and Polarization in Charged Gauge Boson Production at the LHC
13 pages, 8 figures; minor cosmetic change; clarifying remarks on our Feynman rules, add explicit calculation of Ward identities to appendix
Phys.Rev.D82:116011,2010
10.1103/PhysRevD.82.116011
FR-PHENO-2010-028
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the pair production of charged gauge bosons at the LHC in a noncommutative extension of the standard model. We use angular distributions in the decays of the gauge bosons to partially reconstruct polarized cross sections. We use this, together with CP considerations, to construct more sensitive observables that allow to separate space-time from space-space noncommutativities.
[ { "created": "Fri, 27 Aug 2010 12:54:48 GMT", "version": "v1" }, { "created": "Mon, 30 Aug 2010 22:40:20 GMT", "version": "v2" }, { "created": "Thu, 28 Oct 2010 19:13:53 GMT", "version": "v3" } ]
2011-03-07
[ [ "Ohl", "Thorsten", "", "Würzburg University" ], [ "Speckner", "Christian", "", "Freiburg\n University" ] ]
We study the pair production of charged gauge bosons at the LHC in a noncommutative extension of the standard model. We use angular distributions in the decays of the gauge bosons to partially reconstruct polarized cross sections. We use this, together with CP considerations, to construct more sensitive observables that allow to separate space-time from space-space noncommutativities.
1009.2780
Andrew Akeroyd
A.G.Akeroyd, Cheng-Wei Chiang, Naveen Gaur
Leptonic signatures of doubly charged Higgs boson production at the LHC
18 pages, 6 figures, discussion of QCD backgrounds added, version to appear in JHEP
JHEP 1011:005,2010
10.1007/JHEP11(2010)005
SHEP-10-29
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of doubly charged Higgs bosons (H^{\pm\pm}) at the CERN LHC can give rise to distinctive multi-lepton signatures. The discovery potential of H^{\pm\pm} can be optimized by considering a search strategy which is sensitive to both of the dominant production mechanisms, q\bar q\to H^{++}H^{--} and q\bar {q'}\to H^{\pm\pm}H^{\mp}. We compare the discovery potential for the signatures of exactly four leptons and at least three leptons in the final state, using the same set of cuts. We have carried out fast detector simulations at the LHC for both signal and backgrounds for a wide range of values of the charged Higgs mass. We find that the use of the latter channel can substantially improve the detection prospects of the doubly charged Higgs boson at the LHC.
[ { "created": "Tue, 14 Sep 2010 20:43:33 GMT", "version": "v1" }, { "created": "Tue, 26 Oct 2010 20:03:58 GMT", "version": "v2" } ]
2010-11-19
[ [ "Akeroyd", "A. G.", "" ], [ "Chiang", "Cheng-Wei", "" ], [ "Gaur", "Naveen", "" ] ]
The production of doubly charged Higgs bosons (H^{\pm\pm}) at the CERN LHC can give rise to distinctive multi-lepton signatures. The discovery potential of H^{\pm\pm} can be optimized by considering a search strategy which is sensitive to both of the dominant production mechanisms, q\bar q\to H^{++}H^{--} and q\bar {q'}\to H^{\pm\pm}H^{\mp}. We compare the discovery potential for the signatures of exactly four leptons and at least three leptons in the final state, using the same set of cuts. We have carried out fast detector simulations at the LHC for both signal and backgrounds for a wide range of values of the charged Higgs mass. We find that the use of the latter channel can substantially improve the detection prospects of the doubly charged Higgs boson at the LHC.
1602.05392
Sunil Bansal
M. Bansal, S. Bansal, R. Kumar, J. B. Singh
New observables for multiple-parton interactions measurements using Z + jets process at the LHC
17 pages, 7 figures, Accepted for publication in Physical Review D
Phys.Rev. D93 (2016) no.5, 054019
10.1103/PhysRevD.93.054019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiple-parton interactions play a vital role in hadron-hadron collisions. This paper presents a study of the multiple-parton interactions with simulated Z + jets events in proton-proton collisions at a centre-of-mass energy of 13 TeV. The events are simulated with POWHEG followed by hadronization and parton-showering using PYTHIA 8. The events with dimuon invariant mass in the range of 60--120 GeV are selected for the analysis. The charged particle jets, having minimum transverse momentum of 5 GeV and absolute pseudo-rapidity less than 2, are used to construct the observables for measurements of the multiple-parton interactions. The proposed observables and phase-space region presented in this paper found to have enhanced sensitivity to multiple-parton interactions. The increased sensitivity to MPI will be lead to precise constraints on the parameters of the MPI models.
[ { "created": "Wed, 17 Feb 2016 12:54:22 GMT", "version": "v1" } ]
2019-05-02
[ [ "Bansal", "M.", "" ], [ "Bansal", "S.", "" ], [ "Kumar", "R.", "" ], [ "Singh", "J. B.", "" ] ]
Multiple-parton interactions play a vital role in hadron-hadron collisions. This paper presents a study of the multiple-parton interactions with simulated Z + jets events in proton-proton collisions at a centre-of-mass energy of 13 TeV. The events are simulated with POWHEG followed by hadronization and parton-showering using PYTHIA 8. The events with dimuon invariant mass in the range of 60--120 GeV are selected for the analysis. The charged particle jets, having minimum transverse momentum of 5 GeV and absolute pseudo-rapidity less than 2, are used to construct the observables for measurements of the multiple-parton interactions. The proposed observables and phase-space region presented in this paper found to have enhanced sensitivity to multiple-parton interactions. The increased sensitivity to MPI will be lead to precise constraints on the parameters of the MPI models.
hep-ph/0207041
Daijiro Suematsu
Daijiro Suematsu
D-term inflation and neutrino mass
21 pages, LaTeX, small modifications, one reference added
JHEP 0210:014,2002
10.1088/1126-6708/2002/10/014
KANAZAWA-02-11
hep-ph
null
We study a $D$-term inflation scenario in a model extended from the minimal supersymmetric standard model (MSSM) by two additional abelian factor groups focussing on its particle physics aspects. Condensates of the fields related to the inflation can naturally give a possible solution to both the $\mu$-problem in the MSSM and the neutrino mass through their nonrenormalizable couplings to the MSSM fields. Mixings between neutrinos and neutralinos are also induced by some of these condensates. Small neutrino masses are generated by a weak scale seesaw mechanism as a result of these mixings. Moreover, the decay of the condensates may be able to cause the leptogenesis. Usually known discrepancy between both values of a Fayet-Iliopoulos $D$-term which are predicted by the COBE normalization and also by an anomalous U(1) in the weakly-coupled superstring might be reconciled.
[ { "created": "Wed, 3 Jul 2002 07:19:49 GMT", "version": "v1" }, { "created": "Fri, 27 Sep 2002 06:18:16 GMT", "version": "v2" } ]
2014-11-17
[ [ "Suematsu", "Daijiro", "" ] ]
We study a $D$-term inflation scenario in a model extended from the minimal supersymmetric standard model (MSSM) by two additional abelian factor groups focussing on its particle physics aspects. Condensates of the fields related to the inflation can naturally give a possible solution to both the $\mu$-problem in the MSSM and the neutrino mass through their nonrenormalizable couplings to the MSSM fields. Mixings between neutrinos and neutralinos are also induced by some of these condensates. Small neutrino masses are generated by a weak scale seesaw mechanism as a result of these mixings. Moreover, the decay of the condensates may be able to cause the leptogenesis. Usually known discrepancy between both values of a Fayet-Iliopoulos $D$-term which are predicted by the COBE normalization and also by an anomalous U(1) in the weakly-coupled superstring might be reconciled.
hep-ph/9811461
Colin Froggatt
C.D. Froggatt
The Problem of the Quark-Lepton Mass Spectrum
uuencoded 10 page LaTeX file; to appear in the Proceedings of the International Workshop on What comes beyond the Standard Model, Bled, Slovenia 29 June - 9 July 1998
null
null
GUTPA/98/10/04
hep-ph
null
We review some approaches to the quark-lepton mass problem. The ideas of mass-protection and approximate chiral flavour symmetries as a framework for resolving the mass hierarchy problem are presented. Dynamical calculations of the top quark and Higgs particle masses, based on infra-red fixed points and the so-called multiple point principle respectively, are discussed. We also consider mass matrix texture and the neutrino mass puzzle.
[ { "created": "Tue, 24 Nov 1998 17:44:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Froggatt", "C. D.", "" ] ]
We review some approaches to the quark-lepton mass problem. The ideas of mass-protection and approximate chiral flavour symmetries as a framework for resolving the mass hierarchy problem are presented. Dynamical calculations of the top quark and Higgs particle masses, based on infra-red fixed points and the so-called multiple point principle respectively, are discussed. We also consider mass matrix texture and the neutrino mass puzzle.
hep-ph/0503282
Magno Machado
A.I. Lengyel (IEP, National Academy of Sciences of Ukraine, Uzhgorod), M.V.T. Machado (GFPAE, IF UFRGS)
Investigating the role of average color dipole size in BFKL Pomeron phenomenology
null
null
null
null
hep-ph hep-ex
null
Based on the QCD dipole picture of the BFKL Pomeron, we investigate the role played by the saturation scale, Q_{sat}, in obtaining physical values for the affective strong coupling in phenomenological fits to small-x HERA data. The dependence on this scale appears since the collection of color dipoles characterizing the proton target have average size 1/Q_{sat}, which is energy dependent. Physically, this means most of the color dipoles are above but sufficiently close to the border between a saturated and the dilute system. The analysis is first performed in the leading-logs BFKL approach in the saddle-point approximation and it could shed light in further investigations using resummed NLO BFKL kernels
[ { "created": "Tue, 29 Mar 2005 18:27:02 GMT", "version": "v1" }, { "created": "Wed, 30 Mar 2005 15:05:03 GMT", "version": "v2" } ]
2007-05-23
[ [ "Lengyel", "A. I.", "", "IEP, National Academy of Sciences of Ukraine, Uzhgorod" ], [ "Machado", "M. V. T.", "", "GFPAE, IF UFRGS" ] ]
Based on the QCD dipole picture of the BFKL Pomeron, we investigate the role played by the saturation scale, Q_{sat}, in obtaining physical values for the affective strong coupling in phenomenological fits to small-x HERA data. The dependence on this scale appears since the collection of color dipoles characterizing the proton target have average size 1/Q_{sat}, which is energy dependent. Physically, this means most of the color dipoles are above but sufficiently close to the border between a saturated and the dilute system. The analysis is first performed in the leading-logs BFKL approach in the saddle-point approximation and it could shed light in further investigations using resummed NLO BFKL kernels
hep-ph/9801326
Johan Bijnens
Johan Bijnens (Lund), Elisabetta Pallante (Bern) and Joaquim Prades (Granada)
Obtaining K to pi pi from Off-Shell K to pi Amplitudes
LaTeX, 31 pages, 4 postscript figures, uses epsf.sty
Nucl.Phys. B521 (1998) 305-333
10.1016/S0550-3213(98)00202-8
BERN-98/02, LU TP 98-2, UG-FT-78/97
hep-ph hep-lat
null
We properly define off-shell $K\to\pi$ transition amplitudes and use them to extract information for on-shell $K\to\pi\pi$ amplitudes within Chiral Perturbation Theory. At order $p^2$ in the chiral expansion all three parameters of weak interaction can be determined. At order $p^4$ we are able to fix eleven additional constants out of thirteen contributing to off-shell $K\to\pi$ transitions, which leaves four undetermined constants in the on-shell $K\to\pi\pi$ amplitudes. All ${\cal O}(p^4)$ contributions have been exactly derived with $m_\pi^2\ne 0$. We finally discuss the weak mass term issue and find contributions to on-shell $\Delta S=\pm 1$ Kaon decays, in particular to transitions like $K_L \to \gamma \gamma$, $K_L \to \mu^+ \mu^-$ and $K_S \to \pi^0 \gamma \gamma$ at the lowest non-zero order.
[ { "created": "Fri, 16 Jan 1998 13:56:11 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bijnens", "Johan", "", "Lund" ], [ "Pallante", "Elisabetta", "", "Bern" ], [ "Prades", "Joaquim", "", "Granada" ] ]
We properly define off-shell $K\to\pi$ transition amplitudes and use them to extract information for on-shell $K\to\pi\pi$ amplitudes within Chiral Perturbation Theory. At order $p^2$ in the chiral expansion all three parameters of weak interaction can be determined. At order $p^4$ we are able to fix eleven additional constants out of thirteen contributing to off-shell $K\to\pi$ transitions, which leaves four undetermined constants in the on-shell $K\to\pi\pi$ amplitudes. All ${\cal O}(p^4)$ contributions have been exactly derived with $m_\pi^2\ne 0$. We finally discuss the weak mass term issue and find contributions to on-shell $\Delta S=\pm 1$ Kaon decays, in particular to transitions like $K_L \to \gamma \gamma$, $K_L \to \mu^+ \mu^-$ and $K_S \to \pi^0 \gamma \gamma$ at the lowest non-zero order.
hep-ph/0009291
Tsao Chang
Tsao Chang and Guangjiong Ni
Explanation on Negative Mass-Square of Neutrinos
Latex, no figure, 8 pages, v2. references updated; v3. Misprints corrected; v4. Some discussion added
null
null
null
hep-ph
null
It has been known for many years that the measured mass-square of neutrino is probably negative. For solving this puzzle, we have further investigated the hypothesis that neutrinos are superluminal fermions. A new Dirac-type equation is proposed and a tachyonic quantum theory is briefly discussed. This equation is equivalent to two Weyl equations coupled together via nonzero mass while respecting the maximum parity violation, and it reduces to one Weyl equation when the neutrino mass becomes zero.
[ { "created": "Mon, 25 Sep 2000 23:35:45 GMT", "version": "v1" }, { "created": "Tue, 7 Nov 2000 20:48:36 GMT", "version": "v2" }, { "created": "Wed, 3 Jan 2001 20:54:40 GMT", "version": "v3" } ]
2007-05-23
[ [ "Chang", "Tsao", "" ], [ "Ni", "Guangjiong", "" ] ]
It has been known for many years that the measured mass-square of neutrino is probably negative. For solving this puzzle, we have further investigated the hypothesis that neutrinos are superluminal fermions. A new Dirac-type equation is proposed and a tachyonic quantum theory is briefly discussed. This equation is equivalent to two Weyl equations coupled together via nonzero mass while respecting the maximum parity violation, and it reduces to one Weyl equation when the neutrino mass becomes zero.
hep-ph/0207068
Vladimir Nechitailo
I.M. Dremin, V.A. Nechitailo
Moments of the truncated multiplicity distributions
10 pages, LaTeX, 9 ps-figures
Eur.Phys.J.direct C5 (2003) 04; Eur.Phys.J.direct C30 (2003) 004
10.1140/epjcd/s2003-01-004-6
null
hep-ph
null
In experiment, the multiplicity distributions of inelastic processes are truncated due to finite energy, insufficient statistics or special choice of events. It is shown that the moments of such truncated multiplicity distributions possess some typical features.In particular, the oscillations of cumulant moments at high ranks and their negative values at the second rank can be considered as ones most indicative on specifics of these distributions. They allow to distinguish between distributions of different type.
[ { "created": "Thu, 4 Jul 2002 12:02:20 GMT", "version": "v1" } ]
2015-06-25
[ [ "Dremin", "I. M.", "" ], [ "Nechitailo", "V. A.", "" ] ]
In experiment, the multiplicity distributions of inelastic processes are truncated due to finite energy, insufficient statistics or special choice of events. It is shown that the moments of such truncated multiplicity distributions possess some typical features.In particular, the oscillations of cumulant moments at high ranks and their negative values at the second rank can be considered as ones most indicative on specifics of these distributions. They allow to distinguish between distributions of different type.
1907.06960
SImone Rodini
B. Pasquini, S. Rodini, and A. Bacchetta (Pavia U. & INFN, Pavia)
Revisiting model relations between T-odd transverse-momentum dependent parton distributions and generalized parton distributions
15 pages, 2 figures, 1 table, v2: list of references has been corrected
Phys. Rev. D 100, 054039 (2019)
10.1103/PhysRevD.100.054039
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the connection between generalized parton distributions in impact parameter space and T-odd effects in single spin asymmetries of the semi-inclusive deep inelastic process. We show that nontrivial relations can be established only under very specific conditions, typically realized only in models that describe hadrons as two-body bound systems and involving a helicity-conserving coupling between the gauge boson and the spectator system. Examples of these models are the the scalar-diquark spectator model or the quark-target model for the nucleon, and relativistic models for the pion at the lowest order in the Fock-space expansion.
[ { "created": "Tue, 16 Jul 2019 12:37:18 GMT", "version": "v1" }, { "created": "Wed, 17 Jul 2019 18:08:38 GMT", "version": "v2" } ]
2019-10-02
[ [ "Pasquini", "B.", "", "Pavia U. & INFN, Pavia" ], [ "Rodini", "S.", "", "Pavia U. & INFN, Pavia" ], [ "Bacchetta", "A.", "", "Pavia U. & INFN, Pavia" ] ]
We revisit the connection between generalized parton distributions in impact parameter space and T-odd effects in single spin asymmetries of the semi-inclusive deep inelastic process. We show that nontrivial relations can be established only under very specific conditions, typically realized only in models that describe hadrons as two-body bound systems and involving a helicity-conserving coupling between the gauge boson and the spectator system. Examples of these models are the the scalar-diquark spectator model or the quark-target model for the nucleon, and relativistic models for the pion at the lowest order in the Fock-space expansion.
2106.05910
Alfredo Walter Mario Guerrera
Alfredo Walter Mario Guerrera and Stefano Rigolin
Revisiting $K\rightarrow \pi a$ decays
18 pages, 7 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The theoretical calculation for pseudo--scalars hadronic decays $K \to \pi a$ is reviewed. %with the Axion-Like-Particle escaping the detection, While one-loop penguin contributions are usually considered, tree-level processes have most often been overlooked in literature. Following the Lepage--Brodsky approach the tree-level contribution to the charged and neutral pseudo--scalar decay in ALP is estimated. Assuming generic ALP couplings to SM fermions, the latest NA62/E949 results for the $K^+ \to \pi^+ a$ decay and the present/future KOTO results for the $K^0_L \to \pi^0 a$ decay are used to provide updated bounds on the ALP--fermion Lagrangian sector. Finally, the interplay between the tree-level and one-loop contributions is investigated.
[ { "created": "Thu, 10 Jun 2021 16:57:59 GMT", "version": "v1" } ]
2021-06-11
[ [ "Guerrera", "Alfredo Walter Mario", "" ], [ "Rigolin", "Stefano", "" ] ]
The theoretical calculation for pseudo--scalars hadronic decays $K \to \pi a$ is reviewed. %with the Axion-Like-Particle escaping the detection, While one-loop penguin contributions are usually considered, tree-level processes have most often been overlooked in literature. Following the Lepage--Brodsky approach the tree-level contribution to the charged and neutral pseudo--scalar decay in ALP is estimated. Assuming generic ALP couplings to SM fermions, the latest NA62/E949 results for the $K^+ \to \pi^+ a$ decay and the present/future KOTO results for the $K^0_L \to \pi^0 a$ decay are used to provide updated bounds on the ALP--fermion Lagrangian sector. Finally, the interplay between the tree-level and one-loop contributions is investigated.
2403.11318
Joseph Kapusta
Joseph Kapusta, Scott Pratt, Mayank Singh
Anomalous kaon correlations measured in Pb-Pb collisions at the LHC as evidence for the melting and refreezing of the QCD vacuum
4 pages, 4 figures, Quark Matter 2023 Proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision simulators. We consider other conventional statistical models, none of which can reproduce the magnitude and centrality dependence of the correlations. The data can be reproduced by coherent emission from domains which grow in number and volume with increasing centrality. We study the dynamical evolution of the strange quark condensate and show that the energy released during the expansion and cooling of the system may be sufficient to explain the anomaly.
[ { "created": "Sun, 17 Mar 2024 19:45:34 GMT", "version": "v1" } ]
2024-03-19
[ [ "Kapusta", "Joseph", "" ], [ "Pratt", "Scott", "" ], [ "Singh", "Mayank", "" ] ]
Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision simulators. We consider other conventional statistical models, none of which can reproduce the magnitude and centrality dependence of the correlations. The data can be reproduced by coherent emission from domains which grow in number and volume with increasing centrality. We study the dynamical evolution of the strange quark condensate and show that the energy released during the expansion and cooling of the system may be sufficient to explain the anomaly.
hep-ph/0502178
Hong-Jian He
Duane A. Dicus, Hong-Jian He
Scales of Mass Generation for Quarks, Leptons and Majorana Neutrinos
Phys. Rev. Lett.(in press), minor rewording
Phys.Rev.Lett. 94 (2005) 221802
10.1103/PhysRevLett.94.221802
null
hep-ph astro-ph hep-ex
null
We study 2 --> n inelastic fermion-(anti)fermion scattering into multiple longitudinal weak gauge bosons and derive universal upper bounds on the scales of fermion mass generation by imposing unitarity of the S-matrix. We place new upper limits on the scales of fermion mass generation, independent of the electroweak symmetry breaking scale. We find that the strongest 2 --> n limits fall in a narrow range, 3-170 TeV (with n=2-24), depending on the observed fermion masses.
[ { "created": "Sat, 19 Feb 2005 02:10:00 GMT", "version": "v1" }, { "created": "Wed, 27 Apr 2005 19:02:29 GMT", "version": "v2" } ]
2009-11-11
[ [ "Dicus", "Duane A.", "" ], [ "He", "Hong-Jian", "" ] ]
We study 2 --> n inelastic fermion-(anti)fermion scattering into multiple longitudinal weak gauge bosons and derive universal upper bounds on the scales of fermion mass generation by imposing unitarity of the S-matrix. We place new upper limits on the scales of fermion mass generation, independent of the electroweak symmetry breaking scale. We find that the strongest 2 --> n limits fall in a narrow range, 3-170 TeV (with n=2-24), depending on the observed fermion masses.
1801.10403
Marco Bonetti
Marco Bonetti and Kirill Melnikov and Lorenzo Tancredi
Higher order corrections to mixed QCD-EW contributions to Higgs production in gluon fusion
4 pages. Eqs. (7), (13), (14) corrected in this version
Phys. Rev. D 97, 056017 (2018)
10.1103/PhysRevD.97.056017
CERN-TH-2018-011, TTP18-004
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an estimate of the next-to-leading order QCD corrections to mixed QCD-electroweak contribution to Higgs boson production cross section in gluon fusion, combining the recently computed three-loop virtual corrections and the approximate treatment of real emission in the soft approximation. We find that the NLO QCD corrections to mixed QCD-electroweak contributions are nearly identical to NLO QCD corrections to QCD Higgs production. Our result confirms an earlier estimate of these ${\cal O}\left( \alpha\, \alpha_s^2 \right)$ effects in arXiv:0811.3458 [hep-ph] and provides further support for the factorization approximation of QCD and electroweak corrections.
[ { "created": "Wed, 31 Jan 2018 11:14:45 GMT", "version": "v1" }, { "created": "Thu, 19 Apr 2018 15:19:31 GMT", "version": "v2" } ]
2018-04-20
[ [ "Bonetti", "Marco", "" ], [ "Melnikov", "Kirill", "" ], [ "Tancredi", "Lorenzo", "" ] ]
We present an estimate of the next-to-leading order QCD corrections to mixed QCD-electroweak contribution to Higgs boson production cross section in gluon fusion, combining the recently computed three-loop virtual corrections and the approximate treatment of real emission in the soft approximation. We find that the NLO QCD corrections to mixed QCD-electroweak contributions are nearly identical to NLO QCD corrections to QCD Higgs production. Our result confirms an earlier estimate of these ${\cal O}\left( \alpha\, \alpha_s^2 \right)$ effects in arXiv:0811.3458 [hep-ph] and provides further support for the factorization approximation of QCD and electroweak corrections.
hep-ph/9207236
Boris Blok
B. Blok and M. Shifman
The Rule of Discarding $1/N_c$ in Inclusive Weak Decays
preprint NSF-ITP-92-103,TPI-MINN-33/T, 27 pages +2 fig. we eliminate several minor misprints
Nucl.Phys. B399 (1993) 441-458
10.1016/0550-3213(93)90504-I
null
hep-ph
null
We continue to investigate the effects of the (dominant) subleading operator of the $\vec\sigma\vec H$ type in the $1/N_c$ parts of the weak nonleptonic amplitudes. If the previous work concentrated on exclusive decays now we analyse inclusive widths in a certain kinematic limit. Deviations from the parton model predictions are found due to soft-gluon color exchange. In the interference (i.e. $1/N_c$) terms they are stronger than in the non-interference terms. The sign is negative so that the $1/N_c$ parts tend to cancel. The absolute value of the effect is of order 1 in D-mesons and of order 0.50 in B mesons.
[ { "created": "Tue, 14 Jul 1992 08:22:00 GMT", "version": "v1" }, { "created": "Fri, 17 Jul 1992 22:35:00 GMT", "version": "v2" } ]
2009-10-22
[ [ "Blok", "B.", "" ], [ "Shifman", "M.", "" ] ]
We continue to investigate the effects of the (dominant) subleading operator of the $\vec\sigma\vec H$ type in the $1/N_c$ parts of the weak nonleptonic amplitudes. If the previous work concentrated on exclusive decays now we analyse inclusive widths in a certain kinematic limit. Deviations from the parton model predictions are found due to soft-gluon color exchange. In the interference (i.e. $1/N_c$) terms they are stronger than in the non-interference terms. The sign is negative so that the $1/N_c$ parts tend to cancel. The absolute value of the effect is of order 1 in D-mesons and of order 0.50 in B mesons.
1409.3761
Sadataka Furui
Sadataka Furui
Triality selection rules of Octonion and Quantum Mechanics
28 pages, 52 figures, RIKEN workshop 4th Sept. 2014
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply the Cartan's supersymmetric model to the electromagnetic and weak interaction of leptons and hadrons, and study dynamics of $\pi^0,\eta,\eta'$ meson and Higgs boson. We adopt the Clifford algebra, express Pauli spinors by quaternions, Dirac spinors by octonions, and take into account the supersymmetric transformations $G_{ij}$ and $G_{ijk}$ of Cartan. When Higgs boson is assigned as Cartan's spinor pairs $\Psi=\bar\psi\psi$ or $\Phi=\bar\phi\phi$, its decay into $\gamma\gamma\gamma\gamma$ does not occur, but there appear 8 diagrams of $\Psi\to\gamma\gamma$ and 8 diagrams of $\Phi\to\gamma\gamma$. If our world matter makes 4.6\% of the total matter, and we can interpret the matter transformed by $G_{23},G_{12},G_{123},G_{13}, G_{132}$ or about 5 times of our matter, i.e. 23\% corresponds to dark matter. We can assign the world transformed by $G_{12}, G_{123}, G_{13}$ and $G_{132}$, which make about 2/3 of the total corresponds to the dark energy. Experimentally, 72\% of the total matter corresponds to dark energy.
[ { "created": "Fri, 12 Sep 2014 15:06:13 GMT", "version": "v1" }, { "created": "Wed, 26 Nov 2014 09:10:47 GMT", "version": "v2" }, { "created": "Tue, 23 Jun 2015 23:55:36 GMT", "version": "v3" } ]
2015-06-25
[ [ "Furui", "Sadataka", "" ] ]
We apply the Cartan's supersymmetric model to the electromagnetic and weak interaction of leptons and hadrons, and study dynamics of $\pi^0,\eta,\eta'$ meson and Higgs boson. We adopt the Clifford algebra, express Pauli spinors by quaternions, Dirac spinors by octonions, and take into account the supersymmetric transformations $G_{ij}$ and $G_{ijk}$ of Cartan. When Higgs boson is assigned as Cartan's spinor pairs $\Psi=\bar\psi\psi$ or $\Phi=\bar\phi\phi$, its decay into $\gamma\gamma\gamma\gamma$ does not occur, but there appear 8 diagrams of $\Psi\to\gamma\gamma$ and 8 diagrams of $\Phi\to\gamma\gamma$. If our world matter makes 4.6\% of the total matter, and we can interpret the matter transformed by $G_{23},G_{12},G_{123},G_{13}, G_{132}$ or about 5 times of our matter, i.e. 23\% corresponds to dark matter. We can assign the world transformed by $G_{12}, G_{123}, G_{13}$ and $G_{132}$, which make about 2/3 of the total corresponds to the dark energy. Experimentally, 72\% of the total matter corresponds to dark energy.
1508.05210
Won-Gi Paeng
Won-Gi Paeng, Thomas T. S. Kuo, Hyun Kyu Lee and Mannque Rho
Scale-Invariant Hidden Local Symmetry, Topology Change and Dense Baryonic Matter
37 pages and 14 figures, Revised for publication
Phys. Rev. C 93, 055203 (2016)
10.1103/PhysRevC.93.055203
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When scale symmetry is implemented into hidden local symmetry in low-energy strong interactions to arrive at a scale-invariant hidden local symmetric (HLS) theory, the scalar $f_0(500)$ may be interpreted as pseudo-Nambu-Goldstone (pNG) boson, i.e., dilaton, of spontaneously broken scale invariance, joining the pseudo-scalar pNG bosons $\pi$ and the matter fields $V=(\rho,\omega)$ as relevant degrees of freedom. Implementing the skyrmion-half-skyrmion transition predicted at large $N_c$ in QCD at a density roughly twice the nuclear matter density found in the crystal simulation of dense skyrmion matter, we determine the intrinsically density-dependent (IDD) "bare parameters" of the scale-invariant HLS Lagrangian matched to QCD at a matching scale $\Lambda_M$. The resulting effective Lagrangian, with the parameters scaling with the density of the system, is applied to nuclear matter and dense baryonic matter relevant to massive compact stars by means of the double-decimation renormalization-group $V_{lowk}$ formalism. We satisfactorily post-dict the properties of normal nuclear matter and more significantly {\it predict} the EoS of dense compact-star matter that quantitatively accounts for the presently available data coming from both the terrestrial and space laboratories. We interpret the resulting structure of compact-star matter as revealing how the combination of hidden-scale symmetry and hidden local symmetry manifests itself in compressed baryonic matter.
[ { "created": "Fri, 21 Aug 2015 08:46:52 GMT", "version": "v1" }, { "created": "Mon, 12 Oct 2015 09:21:14 GMT", "version": "v2" }, { "created": "Thu, 17 Dec 2015 13:38:05 GMT", "version": "v3" }, { "created": "Mon, 4 Apr 2016 07:08:25 GMT", "version": "v4" } ]
2016-05-18
[ [ "Paeng", "Won-Gi", "" ], [ "Kuo", "Thomas T. S.", "" ], [ "Lee", "Hyun Kyu", "" ], [ "Rho", "Mannque", "" ] ]
When scale symmetry is implemented into hidden local symmetry in low-energy strong interactions to arrive at a scale-invariant hidden local symmetric (HLS) theory, the scalar $f_0(500)$ may be interpreted as pseudo-Nambu-Goldstone (pNG) boson, i.e., dilaton, of spontaneously broken scale invariance, joining the pseudo-scalar pNG bosons $\pi$ and the matter fields $V=(\rho,\omega)$ as relevant degrees of freedom. Implementing the skyrmion-half-skyrmion transition predicted at large $N_c$ in QCD at a density roughly twice the nuclear matter density found in the crystal simulation of dense skyrmion matter, we determine the intrinsically density-dependent (IDD) "bare parameters" of the scale-invariant HLS Lagrangian matched to QCD at a matching scale $\Lambda_M$. The resulting effective Lagrangian, with the parameters scaling with the density of the system, is applied to nuclear matter and dense baryonic matter relevant to massive compact stars by means of the double-decimation renormalization-group $V_{lowk}$ formalism. We satisfactorily post-dict the properties of normal nuclear matter and more significantly {\it predict} the EoS of dense compact-star matter that quantitatively accounts for the presently available data coming from both the terrestrial and space laboratories. We interpret the resulting structure of compact-star matter as revealing how the combination of hidden-scale symmetry and hidden local symmetry manifests itself in compressed baryonic matter.
1312.4254
Sergey Goloskokov
S.V. Goloskokov
Role of transversity in spin effects in meson leptoproduction
Latex, 8 pages, 17 figures, presented at XVth International Workshop on High Energy Spin Physics, October 8 - 12, Dubna, Russia
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the light meson leptoproduction within the handbag approach. We show that effects determined by the transversity Generalized Parton Distributions (GPDs), $H_T$ and $\bar E_T$ are essential in the description of pseudoscalar and vector meson leptoproduction.
[ { "created": "Mon, 16 Dec 2013 06:23:34 GMT", "version": "v1" } ]
2013-12-17
[ [ "Goloskokov", "S. V.", "" ] ]
We analyze the light meson leptoproduction within the handbag approach. We show that effects determined by the transversity Generalized Parton Distributions (GPDs), $H_T$ and $\bar E_T$ are essential in the description of pseudoscalar and vector meson leptoproduction.
1301.5302
Matteo Fael
Matteo Fael, Lorenzo Mercolli, Massimo Passera
Towards a determination of the tau lepton dipole moments
4 pages, presented at the 12th International Workshop on Tau Lepton Physics, Nagoya, Japan, 17-21 September 2012
null
10.1016/j.nuclphysbps.2014.09.025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The tau anomalous magnetic moment (a_tau) and electric dipole moment (d_tau) have not yet been observed. The present bounds on their values are of order 10^-2 and 10^-17 e*cm, respectively. We propose to measure a_tau with a precision of O(10^-3) or better and improve the existing limits on d_tau using precise tau- -> l- nu_tau \bar{nu}_l gamma (l=e or mu) data from high-luminosity B factories. A detailed feasibility study of this method is underway.
[ { "created": "Tue, 22 Jan 2013 20:18:46 GMT", "version": "v1" } ]
2015-06-12
[ [ "Fael", "Matteo", "" ], [ "Mercolli", "Lorenzo", "" ], [ "Passera", "Massimo", "" ] ]
The tau anomalous magnetic moment (a_tau) and electric dipole moment (d_tau) have not yet been observed. The present bounds on their values are of order 10^-2 and 10^-17 e*cm, respectively. We propose to measure a_tau with a precision of O(10^-3) or better and improve the existing limits on d_tau using precise tau- -> l- nu_tau \bar{nu}_l gamma (l=e or mu) data from high-luminosity B factories. A detailed feasibility study of this method is underway.
hep-ph/0009306
Naomichi Suzuki
N.Suzuki and M.Biyajima
Fractional Fokker-Planck Equation and Oscillatory Behavior of Cumulant Moments
10 pages, 8 figures, submitted to Phys. Rev. E
Phys.Rev. E65 (2002) 016123
10.1103/PhysRevE.65.016123
null
hep-ph
null
The Fokker-Planck equation is considered, which is connected to the birth and death process with immigration by the Poisson transform. The fractional derivative in time variable is introduced into the Fokker-Planck equation. From its solution (the probability density function), the generating function (GF) for the corresponding probability distribution is derived. We consider the case when the GF reduces to that of the negative binomial distribution (NBD), if the fractional derivative is replaced to the ordinary one. Formulas of the factorial moment and the $H_j$ moment are derived from the GF. The $H_j$ moment derived from the GF of the NBD decreases monotonously as the rank j increases. However, the $H_j$ moment derived in our approach oscillates, which is contrasted with the case of the NBD. Calculated $H_j$ moments are compared with those given from the data in $p\bar{p}$ collisions and in $e^+e^-$ collisions.
[ { "created": "Wed, 27 Sep 2000 05:41:54 GMT", "version": "v1" }, { "created": "Wed, 25 Oct 2000 05:14:40 GMT", "version": "v2" }, { "created": "Mon, 22 Jan 2001 02:22:44 GMT", "version": "v3" }, { "created": "Tue, 26 Jun 2001 03:24:34 GMT", "version": "v4" } ]
2009-10-31
[ [ "Suzuki", "N.", "" ], [ "Biyajima", "M.", "" ] ]
The Fokker-Planck equation is considered, which is connected to the birth and death process with immigration by the Poisson transform. The fractional derivative in time variable is introduced into the Fokker-Planck equation. From its solution (the probability density function), the generating function (GF) for the corresponding probability distribution is derived. We consider the case when the GF reduces to that of the negative binomial distribution (NBD), if the fractional derivative is replaced to the ordinary one. Formulas of the factorial moment and the $H_j$ moment are derived from the GF. The $H_j$ moment derived from the GF of the NBD decreases monotonously as the rank j increases. However, the $H_j$ moment derived in our approach oscillates, which is contrasted with the case of the NBD. Calculated $H_j$ moments are compared with those given from the data in $p\bar{p}$ collisions and in $e^+e^-$ collisions.
2304.08719
Youichi Yamada
Francesca Borzumati, Kaoru Hagiwara, Kentarou Mawatari, Youichi Yamada, Toshifumi Yamashita
Long-lived Higgsino pairs decaying within the LHC detectors
1+11 pages
null
null
TU-1185
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pair-produced long-lived lightest Higgsinos decaying within a few meters in the LHC detectors are considered. The relatively light nearly-pure Higgsino states object of this study are those of a supersymmetric minimal model with gauge-mediated supersymmetry breaking and heavy sfermions and gauginos. The heavier Higgsinos decay instantly into the lightest one, with very little activities. Hence, all pair-produced Higgsinos end up as a pair of the lightest neutral Higgsinos, possibly long lived and decaying into the gravitino and either the Higgs or the Z boson. If they decay inside the detectors, these bosons deposit huge energies in the calorimeters. The cross section $\sigma_2$ ($\sigma_1$) for the events with two (at least one) decaying-in-flight lightest Higgsinos is examined. The combination $(\sigma_1)^2/\sigma_2$ is found to be almost insensitive to the lightest Higgsino lifetime, thereby providing a good variable to measure its mass. The ratio $\sigma_1/\sigma_2$, instead, mildly dependent on its mass, can give good information on its lifetime. It is argued that the lightest Higgsinos in the events are rather slow, as the very relativistic ones escape away. Thus, the initial state radiations tend to be soft and a trigger system appropriate for such events is necessary to detect them.
[ { "created": "Tue, 18 Apr 2023 04:19:39 GMT", "version": "v1" } ]
2023-04-19
[ [ "Borzumati", "Francesca", "" ], [ "Hagiwara", "Kaoru", "" ], [ "Mawatari", "Kentarou", "" ], [ "Yamada", "Youichi", "" ], [ "Yamashita", "Toshifumi", "" ] ]
Pair-produced long-lived lightest Higgsinos decaying within a few meters in the LHC detectors are considered. The relatively light nearly-pure Higgsino states object of this study are those of a supersymmetric minimal model with gauge-mediated supersymmetry breaking and heavy sfermions and gauginos. The heavier Higgsinos decay instantly into the lightest one, with very little activities. Hence, all pair-produced Higgsinos end up as a pair of the lightest neutral Higgsinos, possibly long lived and decaying into the gravitino and either the Higgs or the Z boson. If they decay inside the detectors, these bosons deposit huge energies in the calorimeters. The cross section $\sigma_2$ ($\sigma_1$) for the events with two (at least one) decaying-in-flight lightest Higgsinos is examined. The combination $(\sigma_1)^2/\sigma_2$ is found to be almost insensitive to the lightest Higgsino lifetime, thereby providing a good variable to measure its mass. The ratio $\sigma_1/\sigma_2$, instead, mildly dependent on its mass, can give good information on its lifetime. It is argued that the lightest Higgsinos in the events are rather slow, as the very relativistic ones escape away. Thus, the initial state radiations tend to be soft and a trigger system appropriate for such events is necessary to detect them.
1304.2232
Max Zoller
M. F. Zoller
OPE of the pseudoscalar gluonium correlator in massless QCD to three-loop order
v2: minor improvements, extended numerics
JHEP 1307 (2013) 040
10.1007/JHEP07(2013)040
TTP13-003, SFB/CPP-13-04
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper analytical results are presented for higher order corrections to coefficient functions of the operator product expansion (OPE) for the correlator of two pseudoscalar gluonium operators \tilde{O}_1=G^{\mu \nu}\tilde{G}_{\mu \nu}. The Wilson coefficient in front of the scalar gluon condensate operator O_1=-1/4 G^{\mu \nu}G_{\mu \nu} is given at three-loop accuracy. The leading coefficient C_0 in front of the unity operator O_0=1 has been calculated up to three-loop order some time ago but has been checked independently in this work. It is interesting to see that the coefficient C_1 in the pseudoscalar case is finite, whereas contact terms appear in C_0 in this case and in both coefficients C_0 and C_1 in the cases of the scalar gluonium correlator and the energy momentum tensor correlator. For the corresponding Renormalization Group invariant Wilson coefficients which are also constructed the results are partially extended to four-loop accuracy. All results are given in the MSbar-scheme at zero temperature.
[ { "created": "Mon, 8 Apr 2013 15:13:11 GMT", "version": "v1" }, { "created": "Fri, 5 Jul 2013 09:51:36 GMT", "version": "v2" } ]
2017-07-25
[ [ "Zoller", "M. F.", "" ] ]
In this paper analytical results are presented for higher order corrections to coefficient functions of the operator product expansion (OPE) for the correlator of two pseudoscalar gluonium operators \tilde{O}_1=G^{\mu \nu}\tilde{G}_{\mu \nu}. The Wilson coefficient in front of the scalar gluon condensate operator O_1=-1/4 G^{\mu \nu}G_{\mu \nu} is given at three-loop accuracy. The leading coefficient C_0 in front of the unity operator O_0=1 has been calculated up to three-loop order some time ago but has been checked independently in this work. It is interesting to see that the coefficient C_1 in the pseudoscalar case is finite, whereas contact terms appear in C_0 in this case and in both coefficients C_0 and C_1 in the cases of the scalar gluonium correlator and the energy momentum tensor correlator. For the corresponding Renormalization Group invariant Wilson coefficients which are also constructed the results are partially extended to four-loop accuracy. All results are given in the MSbar-scheme at zero temperature.
hep-ph/0506085
Sacha Davidson
Sacha Davidson, Martin Gorbahn, Arcadi Santamaria
From transition magnetic moments to majorana neutrino masses
9 pages, final version (improved notation, some mention of the dimension 5 mass operator)
Phys.Lett. B626 (2005) 151-160
10.1016/j.physletb.2005.08.086
LYCEN 2005-18, IPPP/05/23, DCPT/05/46, FTUV/05-0608, IFIC/05-0608
hep-ph
null
It is well known that a majorana mass induces a (small) transition magnetic moment. The converse is also true; in this paper we estimate the loop contribution of transition magnetic moments $[\mu]_{\alpha \beta}$ to the neutrino mass matrix $[m]_{\alpha \beta}$. We show that for hierarchical neutrino masses, the contribution of $[\mu]_{e \tau}$ to $[m]_{e \tau}$ can exceed the experimental value of $[m]_{e \tau}$.
[ { "created": "Wed, 8 Jun 2005 15:55:37 GMT", "version": "v1" }, { "created": "Wed, 12 Oct 2005 13:01:07 GMT", "version": "v2" } ]
2009-11-11
[ [ "Davidson", "Sacha", "" ], [ "Gorbahn", "Martin", "" ], [ "Santamaria", "Arcadi", "" ] ]
It is well known that a majorana mass induces a (small) transition magnetic moment. The converse is also true; in this paper we estimate the loop contribution of transition magnetic moments $[\mu]_{\alpha \beta}$ to the neutrino mass matrix $[m]_{\alpha \beta}$. We show that for hierarchical neutrino masses, the contribution of $[\mu]_{e \tau}$ to $[m]_{e \tau}$ can exceed the experimental value of $[m]_{e \tau}$.
hep-ph/0508273
Abdel-Nasser Tawfik
A. Tawfik
A universal description for the freezeout parameters in heavy-ion collisions
7 pages, 2 eps figures, submitted to Nucl. Phys. A
Nucl.Phys. A764 (2006) 387-392
10.1016/j.nuclphysa.2005.09.005
BI-TP 2005/25
hep-ph
null
It is shown that the freezeout parameters estimated in the heavy-ion collisions all are well described by a constant value of the entropy density $s$ divided by $T^3$. The value of $s/T^3$ has been taken from the lattice QCD simulations at zero baryo-chemical potential $\mu_B$ and assumed to remain constant for finite $\mu_B$. This implies that the hadronic matter in rest frame of produced system can be determined by constant degrees of freedom. Furthermore, this condition has been used to predict the freezeout parameters at low temperatures.
[ { "created": "Fri, 26 Aug 2005 15:28:12 GMT", "version": "v1" } ]
2009-11-11
[ [ "Tawfik", "A.", "" ] ]
It is shown that the freezeout parameters estimated in the heavy-ion collisions all are well described by a constant value of the entropy density $s$ divided by $T^3$. The value of $s/T^3$ has been taken from the lattice QCD simulations at zero baryo-chemical potential $\mu_B$ and assumed to remain constant for finite $\mu_B$. This implies that the hadronic matter in rest frame of produced system can be determined by constant degrees of freedom. Furthermore, this condition has been used to predict the freezeout parameters at low temperatures.
hep-ph/0611237
John Ellis
John Ellis
Physics at LHC
21 pages, 12 figures, Concluding talk at the Physics at LHC conference, Krakow, July 2006
Acta Phys.Polon.B38:1071,2007
null
CERN-PH-TH/2006-239
hep-ph
null
The prospects for physics at the LHC are discussed, starting with the foretaste, preparation (and perhaps scoop) provided by the Tevatron, in particular, and then continuing through the successive phases of LHC operation. These include the start-up phase, the early physics runs, the possible search for new physics in double diffraction, the continuation to nominal LHC running, and the possible upgrade of the LHC luminosity. Emphasis is placed on the prospects for Higgs physics and the search for supersymmetry. The progress and discoveries of the LHC will set the time-scale and agenda for the major future accelerator projects that will follow it.
[ { "created": "Fri, 17 Nov 2006 17:09:06 GMT", "version": "v1" } ]
2009-09-11
[ [ "Ellis", "John", "" ] ]
The prospects for physics at the LHC are discussed, starting with the foretaste, preparation (and perhaps scoop) provided by the Tevatron, in particular, and then continuing through the successive phases of LHC operation. These include the start-up phase, the early physics runs, the possible search for new physics in double diffraction, the continuation to nominal LHC running, and the possible upgrade of the LHC luminosity. Emphasis is placed on the prospects for Higgs physics and the search for supersymmetry. The progress and discoveries of the LHC will set the time-scale and agenda for the major future accelerator projects that will follow it.
hep-ph/0407152
Jurgen Baacke
Jurgen Baacke and Stefan Michalski
The 2PI finite temperature effective potential of the O(N) linear sigma model in 1+1 dimensions, at next-to-leading order in 1/N
19 pages, 9 figures; v2: references added, some changes in the text
Phys.Rev. D70 (2004) 085002
10.1103/PhysRevD.70.085002
DO-TH-04/08
hep-ph hep-th
null
We study the O(N) linear sigma model in 1+1 dimensions. We use the 2PI formalism of Cornwall, Jackiw and Tomboulis in order to evaluate the effective potential at finite temperature. At next-to-leading order in a 1/N expansion one has to include the sums over "necklace" and generalized "sunset" diagrams. We find that - in contrast to the Hartree approximation - there is no spontaneous symmetry breaking in this approximation, as to be expected for the exact theory. The effective potential becomes convex throughout for all parameter sets which include N=4,10,100, couplings lambda=0.1 and 0.5, and temperatures between 0.2 and 1. The Green's functions obtained by solving the Schwinger-Dyson equations are enhanced in the infrared region. We also compare the effective potential as function of the external field phi with those obtained in various other approximations.
[ { "created": "Tue, 13 Jul 2004 17:08:42 GMT", "version": "v1" }, { "created": "Fri, 30 Jul 2004 14:33:03 GMT", "version": "v2" } ]
2016-09-06
[ [ "Baacke", "Jurgen", "" ], [ "Michalski", "Stefan", "" ] ]
We study the O(N) linear sigma model in 1+1 dimensions. We use the 2PI formalism of Cornwall, Jackiw and Tomboulis in order to evaluate the effective potential at finite temperature. At next-to-leading order in a 1/N expansion one has to include the sums over "necklace" and generalized "sunset" diagrams. We find that - in contrast to the Hartree approximation - there is no spontaneous symmetry breaking in this approximation, as to be expected for the exact theory. The effective potential becomes convex throughout for all parameter sets which include N=4,10,100, couplings lambda=0.1 and 0.5, and temperatures between 0.2 and 1. The Green's functions obtained by solving the Schwinger-Dyson equations are enhanced in the infrared region. We also compare the effective potential as function of the external field phi with those obtained in various other approximations.
2208.04847
Goutam Das
Guido Bell, Kevin Brune, Goutam Das, Marcel Wald
Automated Calculation of Beam Functions at NNLO
10 pages, 1 figure, 1 table, Contribution to the proceedings of "Loops and Legs in Quantum Field Theory" - LL2022, 25-30 April, 2022, Ettal, Germany
null
null
SI-HEP-2022-18, P3H-22-085
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present an automated framework for the calculation of beam functions that describe collinear initial-state radiation at hadron colliders at next-to-next-to leading order (NNLO) in perturbation theory. By exploiting the infrared behaviour of the collinear matrix elements, we factorise the phase-space singularities with suitable observable-independent parametrisations. Our numerical approach applies to a large class of collider observables, and as a check of its validity, we compute the quark beam functions for transverse-momentum resummation and N-jettiness, which are known analytically at this order, finding excellent agreement.
[ { "created": "Tue, 9 Aug 2022 15:30:05 GMT", "version": "v1" } ]
2022-08-10
[ [ "Bell", "Guido", "" ], [ "Brune", "Kevin", "" ], [ "Das", "Goutam", "" ], [ "Wald", "Marcel", "" ] ]
We present an automated framework for the calculation of beam functions that describe collinear initial-state radiation at hadron colliders at next-to-next-to leading order (NNLO) in perturbation theory. By exploiting the infrared behaviour of the collinear matrix elements, we factorise the phase-space singularities with suitable observable-independent parametrisations. Our numerical approach applies to a large class of collider observables, and as a check of its validity, we compute the quark beam functions for transverse-momentum resummation and N-jettiness, which are known analytically at this order, finding excellent agreement.
0806.4605
Xavier Calmet
Xavier Calmet, Wei Gong, Stephen D. H. Hsu
Colorful quantum black holes at the LHC
10 pages, to appear in Physics Letters B
Phys.Lett.B668:20-23,2008
10.1016/j.physletb.2008.08.011
CP3-08-22
hep-ph gr-qc hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the LHC phenomenology of quantum black holes in models of TeV gravity. By quantum black holes we mean black holes of the smallest masses and entropies, far from the semiclassical regime. These black holes are formed and decay over short distances, and typically carry SU(3) color charges inherited from their parton progenitors. Based on a few minimal assumptions, such as gauge invariance, we identify interesting signatures for quantum black hole decay such as 2 jets, jet + hard photon, jet + missing energy and jet + charged lepton, which should be readily visible above background. The detailed phenomenology depends heavily on whether one requires a Lorentz invariant, low-energy effective field theory description of black hole processes.
[ { "created": "Fri, 27 Jun 2008 20:00:13 GMT", "version": "v1" }, { "created": "Wed, 6 Aug 2008 22:48:13 GMT", "version": "v2" } ]
2008-11-26
[ [ "Calmet", "Xavier", "" ], [ "Gong", "Wei", "" ], [ "Hsu", "Stephen D. H.", "" ] ]
We examine the LHC phenomenology of quantum black holes in models of TeV gravity. By quantum black holes we mean black holes of the smallest masses and entropies, far from the semiclassical regime. These black holes are formed and decay over short distances, and typically carry SU(3) color charges inherited from their parton progenitors. Based on a few minimal assumptions, such as gauge invariance, we identify interesting signatures for quantum black hole decay such as 2 jets, jet + hard photon, jet + missing energy and jet + charged lepton, which should be readily visible above background. The detailed phenomenology depends heavily on whether one requires a Lorentz invariant, low-energy effective field theory description of black hole processes.
1404.7118
Dean Robinson
Dean J. Robinson and Yuhsin Tsai
A Dynamical Framework for KeV Dirac Neutrino Warm Dark Matter
9 pages, fig 2 added, published version
Phys. Rev. D 90, 045030 (2014)
10.1103/PhysRevD.90.045030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If the source of the reported $3.5$ keV x-ray line is a sterile neutrino, comprising an $\mathcal{O}(1)$ fraction of the dark matter (DM), then it exhibits the property that its mass times mixing angle is $\sim \mbox{few} \times 10^{-2}$ eV, a plausible mass scale for the active neutrinos. This property is a common feature of Dirac neutrino mixing. We present a framework that dynamically produces light active and keV sterile Dirac neutrinos, with appropriate mixing angles to be the x-ray line source. The central idea is that the right-handed active neutrino is a composite state, while elementary sterile neutrinos gain keV masses similarly to the quarks in extended Technicolor. The entire framework is fixed by just two dynamical scales and may automatically exhibit a warm dark matter (WDM) production mechanism -- dilution of thermal relics from late decays of a heavy composite neutrino -- such that the keV neutrinos may comprise an $\mathcal{O}(1)$ fraction of the DM. In this framework, the WDM is typically quite cool and within structure formation bounds, with temperature $\sim \mbox{few}\times 10^{-2}~T_\nu$ and free-streaming length $\sim$ few kpc. A toy model that exhibits the central features of the framework is also presented.
[ { "created": "Mon, 28 Apr 2014 19:59:59 GMT", "version": "v1" }, { "created": "Wed, 28 May 2014 00:35:32 GMT", "version": "v2" }, { "created": "Wed, 6 Aug 2014 16:30:52 GMT", "version": "v3" } ]
2014-09-05
[ [ "Robinson", "Dean J.", "" ], [ "Tsai", "Yuhsin", "" ] ]
If the source of the reported $3.5$ keV x-ray line is a sterile neutrino, comprising an $\mathcal{O}(1)$ fraction of the dark matter (DM), then it exhibits the property that its mass times mixing angle is $\sim \mbox{few} \times 10^{-2}$ eV, a plausible mass scale for the active neutrinos. This property is a common feature of Dirac neutrino mixing. We present a framework that dynamically produces light active and keV sterile Dirac neutrinos, with appropriate mixing angles to be the x-ray line source. The central idea is that the right-handed active neutrino is a composite state, while elementary sterile neutrinos gain keV masses similarly to the quarks in extended Technicolor. The entire framework is fixed by just two dynamical scales and may automatically exhibit a warm dark matter (WDM) production mechanism -- dilution of thermal relics from late decays of a heavy composite neutrino -- such that the keV neutrinos may comprise an $\mathcal{O}(1)$ fraction of the DM. In this framework, the WDM is typically quite cool and within structure formation bounds, with temperature $\sim \mbox{few}\times 10^{-2}~T_\nu$ and free-streaming length $\sim$ few kpc. A toy model that exhibits the central features of the framework is also presented.
hep-ph/0401073
Kristian McDonald
Kristian. L. McDonald and B. H. J. McKellar
The Type-II Singular See-Saw Mechanism
6 pages, v2: minor changes to match published version
Int.J.Mod.Phys.A22:2211-2222,2007
10.1142/S0217751X07036567
null
hep-ph
null
The singular see-saw mechanism is a variation of the see-saw mechanism whereby the right-chiral neutrino Majorana mass matrix is singular. Previous works employing the singular see-saw mechanism have assumed a vanishing left-chiral Majorana mass matrix. We study the neutrino spectrum obtained under a singular see-saw mechanism when the left-chiral neutrinos possess a non-zero Majorana mass matrix. We refer to this as the type-II singular see-saw mechanism. The resulting neutrino spectrum is found to be sensitive to the hierarchy of the Dirac and Majorana mass scales used and we explore the phenomenological consequences of the candidate hierarchies. The compatibility of the resulting spectra with the body of neutrino oscillation data is discussed. It is found that neutrino mass matrices with this structure result in 3+1 or 2+2 neutrino spectra, making it unlikely that this mass matrix structure is realized in nature. If the left-chiral Majorana mass matrix is also singular we show that a type-II singular see-saw mechanism can realize a spectrum of one active-sterile pseudo-Dirac neutrino in conjunction with two active Majorana neutrinos effectively decoupled from the sterile sector. This realizes a scheme discussed in the literature in relation to astrophysical neutrino fluxes.
[ { "created": "Mon, 12 Jan 2004 00:16:42 GMT", "version": "v1" }, { "created": "Tue, 6 Apr 2004 04:48:32 GMT", "version": "v2" }, { "created": "Wed, 9 May 2007 06:09:03 GMT", "version": "v3" } ]
2010-10-28
[ [ "McDonald", "Kristian. L.", "" ], [ "McKellar", "B. H. J.", "" ] ]
The singular see-saw mechanism is a variation of the see-saw mechanism whereby the right-chiral neutrino Majorana mass matrix is singular. Previous works employing the singular see-saw mechanism have assumed a vanishing left-chiral Majorana mass matrix. We study the neutrino spectrum obtained under a singular see-saw mechanism when the left-chiral neutrinos possess a non-zero Majorana mass matrix. We refer to this as the type-II singular see-saw mechanism. The resulting neutrino spectrum is found to be sensitive to the hierarchy of the Dirac and Majorana mass scales used and we explore the phenomenological consequences of the candidate hierarchies. The compatibility of the resulting spectra with the body of neutrino oscillation data is discussed. It is found that neutrino mass matrices with this structure result in 3+1 or 2+2 neutrino spectra, making it unlikely that this mass matrix structure is realized in nature. If the left-chiral Majorana mass matrix is also singular we show that a type-II singular see-saw mechanism can realize a spectrum of one active-sterile pseudo-Dirac neutrino in conjunction with two active Majorana neutrinos effectively decoupled from the sterile sector. This realizes a scheme discussed in the literature in relation to astrophysical neutrino fluxes.
1006.4880
Danilkin Igor
A.M. Badalian, B.L.G. Bakker, I.V. Danilkin
The Hyperfine Splittings in Heavy-Light Mesons and Quarkonia
13 pages
Phys.Atom.Nucl.74:631-642,2011
10.1134/S1063778811040028
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the $B_q$ (q=n,s) mesons are shown to be in full agreement with experiment if a universal coupling $\alpha_{HF}=0.310$ is taken in perturbative spin-spin potential. It gives $M(B^*)-M(B)=45.7(3)$ MeV, $M(B_s^*)-M(B_s)=46.7(3)$ MeV ($n_f=4$), while in bottomonium $\Delta_{HF}(b\bar b)=M(\Upsilon(9460))-M(\eta_b(1S))=63.4$ MeV for $n_f=4$ and 71.1 MeV for $n_f=5$ are obtained; just latter agrees with recent BaBar data. For unobserved excited states we predict $M(\Upsilon(2S))-M(\eta_b(2S))=36(2)$ MeV, $M(\Upsilon(3S))-M(\eta(3S))=28(2)$ MeV, and also $M(B_c^*)=6334(4)$ MeV, $M(B_c(2S))=6868(4)$ MeV, $M(B_c^*(2S))=6905(4)$ MeV. The mass splittings between $D(2^3S_1)-D(2^1S_0)$, $D_s(2^3S_1)-D_s(2^1S_0)$ are predicted to be $\sim 70$ MeV, which are significantly smaller than in several other studies.
[ { "created": "Thu, 24 Jun 2010 21:13:03 GMT", "version": "v1" } ]
2011-05-05
[ [ "Badalian", "A. M.", "" ], [ "Bakker", "B. L. G.", "" ], [ "Danilkin", "I. V.", "" ] ]
Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the $B_q$ (q=n,s) mesons are shown to be in full agreement with experiment if a universal coupling $\alpha_{HF}=0.310$ is taken in perturbative spin-spin potential. It gives $M(B^*)-M(B)=45.7(3)$ MeV, $M(B_s^*)-M(B_s)=46.7(3)$ MeV ($n_f=4$), while in bottomonium $\Delta_{HF}(b\bar b)=M(\Upsilon(9460))-M(\eta_b(1S))=63.4$ MeV for $n_f=4$ and 71.1 MeV for $n_f=5$ are obtained; just latter agrees with recent BaBar data. For unobserved excited states we predict $M(\Upsilon(2S))-M(\eta_b(2S))=36(2)$ MeV, $M(\Upsilon(3S))-M(\eta(3S))=28(2)$ MeV, and also $M(B_c^*)=6334(4)$ MeV, $M(B_c(2S))=6868(4)$ MeV, $M(B_c^*(2S))=6905(4)$ MeV. The mass splittings between $D(2^3S_1)-D(2^1S_0)$, $D_s(2^3S_1)-D_s(2^1S_0)$ are predicted to be $\sim 70$ MeV, which are significantly smaller than in several other studies.
hep-ph/9303309
Janusz Rosiek
P.Chankowski, S.Pokorski and J.Rosiek
Complete On-Shell Renormalization Scheme for the Minimal Supersymmetric Higgs Sector
64 pages, 10 figures (not included, availaible on request in PostScript format), LaTeX, preprint no MPI-Ph/92-117 and DFPD 93/TH/13
Nucl.Phys. B423 (1994) 437-496
10.1016/0550-3213(94)90141-4
null
hep-ph
null
Systematic on-shell renormalization programme is carried out for the Higgs and gauge boson sectors of the Minimal Supersymmetric Standard Model. Complete 1-loop results for the 2- and 3-point Green's functions are explicitly given. The Higgs boson masses and the cross sections for the neutral scalar production in the $e^+e^-$ colliders are calculated.
[ { "created": "Fri, 26 Mar 1993 13:27:11 GMT", "version": "v1" } ]
2009-10-22
[ [ "Chankowski", "P.", "" ], [ "Pokorski", "S.", "" ], [ "Rosiek", "J.", "" ] ]
Systematic on-shell renormalization programme is carried out for the Higgs and gauge boson sectors of the Minimal Supersymmetric Standard Model. Complete 1-loop results for the 2- and 3-point Green's functions are explicitly given. The Higgs boson masses and the cross sections for the neutral scalar production in the $e^+e^-$ colliders are calculated.
1905.12939
Jian Tang
Gui-Jun Ding, Yu-Feng Li, Jian Tang and Tse-Chun Wang
Confronting Tri-direct CP-symmetry models to neutrino oscillation experiments
18 pages, 8 figures. Update texts and accepted in PRD
Phys. Rev. D 100, 055022 (2019)
10.1103/PhysRevD.100.055022
USTC-ICTS-19-10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tri-direct CP symmetry is an economical neutrino model building paradigm, and it allows to describe neutrino masses, mixing angles and CP violation phases in terms of four free parameters. Viability of a class of tri-direct CP models is examined with a comprehensive simulation of current and future neutrino oscillation experiments. Two benchmark models as well as the full parameter space are carefully scanned, and the parameter degeneracy problem is observed from the constraint of one group of neutrino oscillation experiments. Complementary roles from the accelerator neutrino experiments (e.g., T2HK and DUNE) and reactor neutrino experiments (e.g., JUNO) are crucial to break the degeneracy and nail down fundamental neutrino mixing parameters of the underlying theory.
[ { "created": "Thu, 30 May 2019 09:54:44 GMT", "version": "v1" }, { "created": "Fri, 23 Aug 2019 04:13:40 GMT", "version": "v2" } ]
2019-09-25
[ [ "Ding", "Gui-Jun", "" ], [ "Li", "Yu-Feng", "" ], [ "Tang", "Jian", "" ], [ "Wang", "Tse-Chun", "" ] ]
Tri-direct CP symmetry is an economical neutrino model building paradigm, and it allows to describe neutrino masses, mixing angles and CP violation phases in terms of four free parameters. Viability of a class of tri-direct CP models is examined with a comprehensive simulation of current and future neutrino oscillation experiments. Two benchmark models as well as the full parameter space are carefully scanned, and the parameter degeneracy problem is observed from the constraint of one group of neutrino oscillation experiments. Complementary roles from the accelerator neutrino experiments (e.g., T2HK and DUNE) and reactor neutrino experiments (e.g., JUNO) are crucial to break the degeneracy and nail down fundamental neutrino mixing parameters of the underlying theory.
1812.04089
Oliver Gould
Oliver Gould, Stuart Mangles, Arttu Rajantie, Steven Rose and Cheng Xie
Observing Thermal Schwinger Pair Production
8 pages, 5 figures, published in PRA
Phys. Rev. A 99, 052120 (2019)
10.1103/PhysRevA.99.052120
HIP-2018-31/TH, IMPERIAL-TP-2018-AR-2
hep-ph physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility of observing Schwinger pair production enhanced by a thermal bath of photons. We consider the full range of temperatures and electric field intensities from pure Schwinger production to pure thermal production, and identify the most promising and interesting regimes. In particular, we identify temperatures of $\sim 20~\mathrm{keV}/k_B$ and field intensities of $\sim 10^{23}~\mathrm{Wcm}^{-2}$ where pair production would be observable. In this case, the thermal enhancement over the Schwinger rate is exponentially large and due to effects which are not visible at any finite order in the loop expansion. Pair production in this regime can thus be described as more nonperturbative than the usual Schwinger process, which appears at one loop. Unfortunately, such high temperatures appear to be out of reach of foreseeable technologies, though nonthermal photon distributions with comparable energy densities are possible. We suggest the possibility that similar nonperturbative enhancements may extend out of equilibrium and propose an experimental scheme to test this.
[ { "created": "Mon, 10 Dec 2018 21:07:53 GMT", "version": "v1" }, { "created": "Tue, 28 May 2019 10:37:07 GMT", "version": "v2" } ]
2019-05-29
[ [ "Gould", "Oliver", "" ], [ "Mangles", "Stuart", "" ], [ "Rajantie", "Arttu", "" ], [ "Rose", "Steven", "" ], [ "Xie", "Cheng", "" ] ]
We study the possibility of observing Schwinger pair production enhanced by a thermal bath of photons. We consider the full range of temperatures and electric field intensities from pure Schwinger production to pure thermal production, and identify the most promising and interesting regimes. In particular, we identify temperatures of $\sim 20~\mathrm{keV}/k_B$ and field intensities of $\sim 10^{23}~\mathrm{Wcm}^{-2}$ where pair production would be observable. In this case, the thermal enhancement over the Schwinger rate is exponentially large and due to effects which are not visible at any finite order in the loop expansion. Pair production in this regime can thus be described as more nonperturbative than the usual Schwinger process, which appears at one loop. Unfortunately, such high temperatures appear to be out of reach of foreseeable technologies, though nonthermal photon distributions with comparable energy densities are possible. We suggest the possibility that similar nonperturbative enhancements may extend out of equilibrium and propose an experimental scheme to test this.
2305.05225
Gabriele Ferrari
Alessandro Zenesini, Anna Berti, Riccardo Cominotti, Chiara Rogora, Ian G. Moss, Thomas P. Billam, Iacopo Carusotto, Giacomo Lamporesi, Alessio Recati, Gabriele Ferrari
Observation of false vacuum decay via bubble formation in ferromagnetic superfluids
12 pages, 9 figures
Nat. Phys. 20, 558 (2024)
10.1038/s41567-023-02345-4
null
hep-ph cond-mat.quant-gas cond-mat.stat-mech hep-th quant-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
In quantum field theory, the decay of an extended metastable state into the real ground state is known as ``false vacuum decay'' and it takes place via the nucleation of spatially localized bubbles. Despite the large theoretical effort to estimate the nucleation rate, experimental observations were still missing. Here, we observe bubble nucleation in isolated and highly controllable superfluid atomic systems, and we find good agreement between our results, numerical simulations and instanton theory opening the way to the emulation of out-of-equilibrium quantum field phenomena in atomic systems.
[ { "created": "Tue, 9 May 2023 07:41:08 GMT", "version": "v1" } ]
2024-07-16
[ [ "Zenesini", "Alessandro", "" ], [ "Berti", "Anna", "" ], [ "Cominotti", "Riccardo", "" ], [ "Rogora", "Chiara", "" ], [ "Moss", "Ian G.", "" ], [ "Billam", "Thomas P.", "" ], [ "Carusotto", "Iacopo", "" ], [ "Lamporesi", "Giacomo", "" ], [ "Recati", "Alessio", "" ], [ "Ferrari", "Gabriele", "" ] ]
In quantum field theory, the decay of an extended metastable state into the real ground state is known as ``false vacuum decay'' and it takes place via the nucleation of spatially localized bubbles. Despite the large theoretical effort to estimate the nucleation rate, experimental observations were still missing. Here, we observe bubble nucleation in isolated and highly controllable superfluid atomic systems, and we find good agreement between our results, numerical simulations and instanton theory opening the way to the emulation of out-of-equilibrium quantum field phenomena in atomic systems.
hep-ph/9503435
null
A.P.Kobushkin, A.I.Syamtomov and L.Ya.Glozman
Quark-exchange Effects in a Deuteron Breakup at Intermediate Energy
LaTeX, 13 pages+8 (ps-figures)
Phys.Atom.Nucl. 59 (1996) 795-803; Yad.Fiz. 59N5 (1996) 833-841
null
ITP-95-9E
hep-ph
null
Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the $6q$-deuteron wave function with respect to the pair permutations of quark variables, strongly affect the proton momentum distribution in the deuteron, as well as the polarization observables of inclusive deuteron breakup, when the ``internal momentum'' in the deuteron is of order of a few hundreds MeV/c.
[ { "created": "Sat, 25 Mar 1995 08:09:19 GMT", "version": "v1" } ]
2009-09-25
[ [ "Kobushkin", "A. P.", "" ], [ "Syamtomov", "A. I.", "" ], [ "Glozman", "L. Ya.", "" ] ]
Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the $6q$-deuteron wave function with respect to the pair permutations of quark variables, strongly affect the proton momentum distribution in the deuteron, as well as the polarization observables of inclusive deuteron breakup, when the ``internal momentum'' in the deuteron is of order of a few hundreds MeV/c.
1704.04911
Barbara Jager
B. Jager, L. Salfelder, M. Worek, D. Zeppenfeld
Physics Opportunities for Vector-Boson Scattering at a Future 100 TeV Hadron Collider
26 pages, 14 figures; matches version published by Phys. Rev. D
Phys. Rev. D 96, 073008 (2017)
10.1103/PhysRevD.96.073008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Vector-boson scattering (VBS) processes provide particularly promising means for probing the mechanism of electroweak symmetry breaking and to search for new physics in the weak sector. In the environment of a future proton-proton collider operating at a center-of-mass energy of 100 TeV, unprecedented opportunities arise for the investigation of this important class of reactions. We highlight the prominent features of VBS processes in this energy regime and discuss how the VBS signal can be isolated in the presence of a priori large QCD backgrounds. We find excellent opportunities for the analysis of VBS reactions in a kinematic range that is inaccessible to present colliders.
[ { "created": "Mon, 17 Apr 2017 09:23:46 GMT", "version": "v1" }, { "created": "Mon, 30 Oct 2017 07:35:59 GMT", "version": "v2" } ]
2017-11-01
[ [ "Jager", "B.", "" ], [ "Salfelder", "L.", "" ], [ "Worek", "M.", "" ], [ "Zeppenfeld", "D.", "" ] ]
Vector-boson scattering (VBS) processes provide particularly promising means for probing the mechanism of electroweak symmetry breaking and to search for new physics in the weak sector. In the environment of a future proton-proton collider operating at a center-of-mass energy of 100 TeV, unprecedented opportunities arise for the investigation of this important class of reactions. We highlight the prominent features of VBS processes in this energy regime and discuss how the VBS signal can be isolated in the presence of a priori large QCD backgrounds. We find excellent opportunities for the analysis of VBS reactions in a kinematic range that is inaccessible to present colliders.
2305.05788
Yan Wang
Z. Li, A. Arhrib, R. Benbrik, M. Krab, B. Manaut, S. Moretti, Y. Wang and Q.S. Yan
Discovering a light charged Higgs boson via $W^{\pm *}$ + 4$b$ final states at the LHC
20 pages, 9 figures, 7 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Most of the current experimental searches for charged Higgs bosons at the Large Hadron Collider (LHC) concentrate upon the $tb$ and $\tau\nu$ decay channels. In the present study, we analyze instead the feasibility of the bosonic decay channel $W^{\pm *} h$, with the charged gauge boson being off-shell and $h$ being a neutral light Higgs boson, which decays predominantly into $b\bar{b}$. We perform a Monte Carlo (MC) analysis for the associate production of a charged Higgs with such a light neutral one, $pp\to H^\pm h$, at the LHC followed by the aforementioned charged Higgs boson decay, which leads to a $W^{\pm *} +4b$ final state. The analysis is performed within the 2-Higgs Doublet Model (2HDM) with Yukawa texture of Type-I. We take into account all available experimental constraints from LEP, Tevatron and the LHC as well as the theoretical requirements of self-consistency of this scenario. In order to study the full process $pp \rightarrow H^{\pm} h \rightarrow W^{\pm *} h h \rightarrow \ell^\pm \nu+ 4b$ ($\ell=e,\mu$), we provide several Benchmark Points (BPs) amenable to further analysis, with $M_{H^\pm}+M_{b} < M_{t}$, for which we prove that there is a strong possibility that this spectacular signal could be found at the LHC with center of mass energy 14 TeV and luminosity 300 $\rm{fb}^{-1}$.
[ { "created": "Tue, 9 May 2023 22:20:30 GMT", "version": "v1" }, { "created": "Wed, 17 May 2023 07:37:28 GMT", "version": "v2" } ]
2023-05-18
[ [ "Li", "Z.", "" ], [ "Arhrib", "A.", "" ], [ "Benbrik", "R.", "" ], [ "Krab", "M.", "" ], [ "Manaut", "B.", "" ], [ "Moretti", "S.", "" ], [ "Wang", "Y.", "" ], [ "Yan", "Q. S.", "" ] ]
Most of the current experimental searches for charged Higgs bosons at the Large Hadron Collider (LHC) concentrate upon the $tb$ and $\tau\nu$ decay channels. In the present study, we analyze instead the feasibility of the bosonic decay channel $W^{\pm *} h$, with the charged gauge boson being off-shell and $h$ being a neutral light Higgs boson, which decays predominantly into $b\bar{b}$. We perform a Monte Carlo (MC) analysis for the associate production of a charged Higgs with such a light neutral one, $pp\to H^\pm h$, at the LHC followed by the aforementioned charged Higgs boson decay, which leads to a $W^{\pm *} +4b$ final state. The analysis is performed within the 2-Higgs Doublet Model (2HDM) with Yukawa texture of Type-I. We take into account all available experimental constraints from LEP, Tevatron and the LHC as well as the theoretical requirements of self-consistency of this scenario. In order to study the full process $pp \rightarrow H^{\pm} h \rightarrow W^{\pm *} h h \rightarrow \ell^\pm \nu+ 4b$ ($\ell=e,\mu$), we provide several Benchmark Points (BPs) amenable to further analysis, with $M_{H^\pm}+M_{b} < M_{t}$, for which we prove that there is a strong possibility that this spectacular signal could be found at the LHC with center of mass energy 14 TeV and luminosity 300 $\rm{fb}^{-1}$.
2006.03788
Atsushi Hosaka
Takashi Ezoe and Atsushi Hosaka
Lambda(1405) as a K-bar N Feshbach resonance in the Skyrme model
null
Phys. Rev. D 102, 014046 (2020)
10.1103/PhysRevD.102.014046
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the Lambda(1405) hyperon as a Feshbach resonance of a bar-KN quasi-bound state coupled by a decaying channel of pi Sigma in the Skyrme model. A weakly bound bar-KN state is generated in the laboratory frame, while the Sigma hyperon as a strongly bound state of bar-KN in the intrinsic frame. We obtain a coupling of bar-KN and pi Sigma channels by computing a baryon matrix element of the axial current. This coupling enables the decay of the bar-KN bound state to pi-Sigma . It is shown that the Skyrme model supports the Lambda(1405) as a narrow Feshbach resonance.
[ { "created": "Sat, 6 Jun 2020 06:09:32 GMT", "version": "v1" } ]
2020-08-05
[ [ "Ezoe", "Takashi", "" ], [ "Hosaka", "Atsushi", "" ] ]
We describe the Lambda(1405) hyperon as a Feshbach resonance of a bar-KN quasi-bound state coupled by a decaying channel of pi Sigma in the Skyrme model. A weakly bound bar-KN state is generated in the laboratory frame, while the Sigma hyperon as a strongly bound state of bar-KN in the intrinsic frame. We obtain a coupling of bar-KN and pi Sigma channels by computing a baryon matrix element of the axial current. This coupling enables the decay of the bar-KN bound state to pi-Sigma . It is shown that the Skyrme model supports the Lambda(1405) as a narrow Feshbach resonance.
2009.11870
Seth Koren
Seth Koren
The Hierarchy Problem: From the Fundamentals to the Frontiers
PhD thesis with 150+ pages new pedagogical introductory material. Two dozen drawings, 14 epigraphs, many footnotes. Comments and reference recommendations welcome
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We begin this thesis with an extensive pedagogical introduction aimed at clarifying the foundations of the hierarchy problem. After introducing effective field theory, we discuss renormalization at length from a variety of perspectives. We focus on conceptual understanding and connections between approaches, while providing a plethora of examples for clarity. With that background we can then clearly understand the hierarchy problem, which is reviewed primarily by introducing and refuting common misconceptions thereof. We next discuss some of the beautiful classic frameworks to approach the issue. However, we argue that the LHC data have qualitatively modified the issue into `The Loerarchy Problem'---how to generate an IR scale without accompanying visible structure---and we discuss recent work on this approach. In the second half, we present some of our own work in these directions, beginning with explorations of how the Neutral Naturalness approach motivates novel signatures of electroweak naturalness at a variety of physics frontiers. Finally, we propose a New Trail for Naturalness and suggest that the physical breakdown of EFT, which gravity demands, may be responsible for the violation of our EFT expectations at the LHC.
[ { "created": "Thu, 24 Sep 2020 18:00:00 GMT", "version": "v1" } ]
2020-09-28
[ [ "Koren", "Seth", "" ] ]
We begin this thesis with an extensive pedagogical introduction aimed at clarifying the foundations of the hierarchy problem. After introducing effective field theory, we discuss renormalization at length from a variety of perspectives. We focus on conceptual understanding and connections between approaches, while providing a plethora of examples for clarity. With that background we can then clearly understand the hierarchy problem, which is reviewed primarily by introducing and refuting common misconceptions thereof. We next discuss some of the beautiful classic frameworks to approach the issue. However, we argue that the LHC data have qualitatively modified the issue into `The Loerarchy Problem'---how to generate an IR scale without accompanying visible structure---and we discuss recent work on this approach. In the second half, we present some of our own work in these directions, beginning with explorations of how the Neutral Naturalness approach motivates novel signatures of electroweak naturalness at a variety of physics frontiers. Finally, we propose a New Trail for Naturalness and suggest that the physical breakdown of EFT, which gravity demands, may be responsible for the violation of our EFT expectations at the LHC.
2003.09781
Jin-Lei Yang
Jin-Lei Yang, Tai-Fu Feng, Hai-Bin Zhang
Electron and muon $(g-2)$ in the B-LSSM
18 pages, 6figures
J. Phys. G: Nucl. Part. Phys. 47 (2020) 055004
10.1088/1361-6471/ab7986
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The theoretical predictions in the standard model (SM) and measurements on the anomalous magnetic dipole moments (MDM) of muon and electron have great precision, hence the MDMs of muon and electron have close relation with the new physics (NP) beyond the SM. Recently, a negative $\sim2.4\sigma$ discrepancy between the measured electron MDM and the SM prediction results from a recent improved determination of the fine structure constant. Combined with the long-lasting muon MDM discrepancy which is about $\sim3.7\sigma$, it is difficult to explain both the magnitude and opposite signs of the deviations in a consistent model, without introducing large flavour-violating effects. The analysis shows that they can be explained in the minimal supersymmetric extension (MSSM) of the SM with local $B-L$ gauge symmetry (B-LSSM). Comparing with the MSSM, new parameters in the B-LSSM can affect the theoretical predictions on lepton MDMs, and the effects of them are explored.
[ { "created": "Sun, 22 Mar 2020 01:41:35 GMT", "version": "v1" }, { "created": "Thu, 9 Apr 2020 00:44:09 GMT", "version": "v2" } ]
2020-04-10
[ [ "Yang", "Jin-Lei", "" ], [ "Feng", "Tai-Fu", "" ], [ "Zhang", "Hai-Bin", "" ] ]
The theoretical predictions in the standard model (SM) and measurements on the anomalous magnetic dipole moments (MDM) of muon and electron have great precision, hence the MDMs of muon and electron have close relation with the new physics (NP) beyond the SM. Recently, a negative $\sim2.4\sigma$ discrepancy between the measured electron MDM and the SM prediction results from a recent improved determination of the fine structure constant. Combined with the long-lasting muon MDM discrepancy which is about $\sim3.7\sigma$, it is difficult to explain both the magnitude and opposite signs of the deviations in a consistent model, without introducing large flavour-violating effects. The analysis shows that they can be explained in the minimal supersymmetric extension (MSSM) of the SM with local $B-L$ gauge symmetry (B-LSSM). Comparing with the MSSM, new parameters in the B-LSSM can affect the theoretical predictions on lepton MDMs, and the effects of them are explored.
1111.7050
Bo-Qiang Ma
Bo-Qiang Ma
The Phantom of the OPERA: Superluminal Neutrinos
10 latex pages. Final version for journal publication
Mod.Phys.Lett.A 27,1230005(2012)
10.1142/S0217732312300054
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This report presents a brief review on the experimental measurements of the muon neutrino velocities from the OPERA, Fermilab and MINOS experiments and that of the (anti)-electron neutrino velocities from the supernova SN1987A, and consequently on the theoretical attempts to attribute the data as signals for superluminality of neutrinos. Different scenarios on how to understand and treat the background fields in the effective field theory frameworks are pointed out. Challenges on interpreting the OPERA result as a signal of neutrino superluminality are briefly reviewed and discussed. It is also pointed out that a covariant picture of Lorentz violation may avoid the refutation on the OPERA experiment.
[ { "created": "Wed, 30 Nov 2011 05:28:04 GMT", "version": "v1" }, { "created": "Thu, 1 Dec 2011 17:19:15 GMT", "version": "v2" }, { "created": "Fri, 30 Dec 2011 13:06:46 GMT", "version": "v3" }, { "created": "Thu, 19 Jan 2012 01:36:34 GMT", "version": "v4" }, { "created": "Thu, 26 Jan 2012 03:45:51 GMT", "version": "v5" } ]
2012-01-27
[ [ "Ma", "Bo-Qiang", "" ] ]
This report presents a brief review on the experimental measurements of the muon neutrino velocities from the OPERA, Fermilab and MINOS experiments and that of the (anti)-electron neutrino velocities from the supernova SN1987A, and consequently on the theoretical attempts to attribute the data as signals for superluminality of neutrinos. Different scenarios on how to understand and treat the background fields in the effective field theory frameworks are pointed out. Challenges on interpreting the OPERA result as a signal of neutrino superluminality are briefly reviewed and discussed. It is also pointed out that a covariant picture of Lorentz violation may avoid the refutation on the OPERA experiment.
0811.0772
Tobias Toll
Tobias Toll (Desy)
MC@NLO for Heavy Quarks in Photoproduction
4 pages, DIS08 proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An MC@NLO for heavy quarks in photoproduction is presented. This is the first lepton-hadron process to be included into MC@NLO. To construct an MC@NLO process dependent so called MC-subtraction terms need to be calculated. The resulting calculation is compared to a fixed order NLO calculation and the HERWIG event generator and is shown to perform well.
[ { "created": "Wed, 5 Nov 2008 16:43:59 GMT", "version": "v1" } ]
2011-09-07
[ [ "Toll", "Tobias", "", "Desy" ] ]
An MC@NLO for heavy quarks in photoproduction is presented. This is the first lepton-hadron process to be included into MC@NLO. To construct an MC@NLO process dependent so called MC-subtraction terms need to be calculated. The resulting calculation is compared to a fixed order NLO calculation and the HERWIG event generator and is shown to perform well.
hep-ph/9705266
null
S.M. Barr (Bartol Research Institute)
The Sliding-singlet Mechanism Revived
xx pages, LaTeX. Note added
Phys.Rev.D57:190-194,1998
10.1103/PhysRevD.57.190
BA-97-17
hep-ph
null
It is shown, using a modification of an idea of Sen, that completely realistic supersymmetric grand-unified theories based on SU(6) or larger unitary groups can be constructed using the sliding-singlet mechanism. These models have a simple structure, preserve the successful prediction of $\sin^2 \theta_W$, and can suppress Higgsino-mediated proton decay to an acceptable level in a simple way.
[ { "created": "Thu, 8 May 1997 15:33:06 GMT", "version": "v1" }, { "created": "Thu, 5 Jun 1997 17:53:43 GMT", "version": "v2" } ]
2011-05-12
[ [ "Barr", "S. M.", "", "Bartol Research Institute" ] ]
It is shown, using a modification of an idea of Sen, that completely realistic supersymmetric grand-unified theories based on SU(6) or larger unitary groups can be constructed using the sliding-singlet mechanism. These models have a simple structure, preserve the successful prediction of $\sin^2 \theta_W$, and can suppress Higgsino-mediated proton decay to an acceptable level in a simple way.
hep-ph/9603429
Wolfgang Lucha
Wolfgang Lucha and Franz F. Sch\"oberl
Relativistic Coulomb Problem: Analytic Upper Bounds on Energy Levels
12 pages, LaTeX
Phys.Rev.A54:3790-3794,1996
10.1103/PhysRevA.54.3790
HEPHY-PUB 632/96
hep-ph hep-th
null
The spinless relativistic Coulomb problem is the bound-state problem for the spinless Salpeter equation (a standard approximation to the Bethe--Salpeter formalism as well as the most simple generalization of the nonrelativistic Schr\"odinger formalism towards incorporation of relativistic effects) with the Coulomb interaction potential (the static limit of the exchange of some massless bosons, as present in unbroken gauge theories). The nonlocal nature of the Hamiltonian encountered here, however, renders extremely difficult to obtain rigorous analytic statements on the corresponding solutions. In view of this rather unsatisfactory state of affairs, we derive (sets of) analytic upper bounds on the involved energy eigenvalues.
[ { "created": "Thu, 28 Mar 1996 12:57:58 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lucha", "Wolfgang", "" ], [ "Schöberl", "Franz F.", "" ] ]
The spinless relativistic Coulomb problem is the bound-state problem for the spinless Salpeter equation (a standard approximation to the Bethe--Salpeter formalism as well as the most simple generalization of the nonrelativistic Schr\"odinger formalism towards incorporation of relativistic effects) with the Coulomb interaction potential (the static limit of the exchange of some massless bosons, as present in unbroken gauge theories). The nonlocal nature of the Hamiltonian encountered here, however, renders extremely difficult to obtain rigorous analytic statements on the corresponding solutions. In view of this rather unsatisfactory state of affairs, we derive (sets of) analytic upper bounds on the involved energy eigenvalues.
2112.02971
Hang Li
Hang Li and P. Wang
Solution of lepton $g-2$ anomalies with nonlocal QED
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The explanation for lepton $g-2$ anomalies is provided with the nonlocal QED which is the simple extension of the standard model. This solution is based on the same gauge symmetry as QED without introducing any new particles and interactions. The correlation functions in the nonlocal strength tension and lepton-photon interaction make it possible to explain the discrepancies of both $\Delta a_\mu$ and $\Delta a_e$. With the same approach, the discrepancy of anomalous magnetic moment of $\tau$ lepton from standard model is estimated in the range $1.19\times10^{-5}$ to $3.21\times10^{-3}$ which is covered by the current experimental uncertainty.
[ { "created": "Mon, 6 Dec 2021 12:36:45 GMT", "version": "v1" }, { "created": "Fri, 16 Sep 2022 07:44:54 GMT", "version": "v2" } ]
2022-09-19
[ [ "Li", "Hang", "" ], [ "Wang", "P.", "" ] ]
The explanation for lepton $g-2$ anomalies is provided with the nonlocal QED which is the simple extension of the standard model. This solution is based on the same gauge symmetry as QED without introducing any new particles and interactions. The correlation functions in the nonlocal strength tension and lepton-photon interaction make it possible to explain the discrepancies of both $\Delta a_\mu$ and $\Delta a_e$. With the same approach, the discrepancy of anomalous magnetic moment of $\tau$ lepton from standard model is estimated in the range $1.19\times10^{-5}$ to $3.21\times10^{-3}$ which is covered by the current experimental uncertainty.
hep-ph/9708254
null
R. Arnowitt and Pran Nath
Supergravity Unified Models
Latex, 21 pages, to appear in book "Perspectives on Supergravity", World Scientific, Editor G. Kane; reference numbers and minor typos corrected
null
10.1142/9789812839657_0019
null
hep-ph hep-ex hep-th
null
The development of supergravity unified models and their implications for current and future experiments are discussed.
[ { "created": "Tue, 5 Aug 1997 21:05:50 GMT", "version": "v1" }, { "created": "Wed, 10 Sep 1997 17:13:15 GMT", "version": "v2" } ]
2016-11-03
[ [ "Arnowitt", "R.", "" ], [ "Nath", "Pran", "" ] ]
The development of supergravity unified models and their implications for current and future experiments are discussed.
0901.1998
Yun Guo
Adrian Dumitru, Yun Guo, Agnes Mocsy, Michael Strickland
Quarkonium states in an anisotropic QCD plasma
18 pages, 6 figures, final version, to appear in PRD
Phys.Rev.D79:054019,2009
10.1103/PhysRevD.79.054019
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider quarkonium in a hot QCD plasma which, due to expansion and non-zero viscosity, exhibits a local anisotropy in momentum space. At short distances the heavy-quark potential is known at tree level from the hard-thermal loop resummed gluon propagator in anisotropic perturbative QCD. The potential at long distances is modeled as a QCD string which is screened at the same scale as the Coulomb field. At asymptotic separation the potential energy is non-zero and inversely proportional to the temperature. We obtain numerical solutions of the three-dimensional Schroedinger equation for this potential. We find that quarkonium binding is stronger at non-vanishing viscosity and expansion rate, and that the anisotropy leads to polarization of the P-wave states.
[ { "created": "Wed, 14 Jan 2009 13:20:19 GMT", "version": "v1" }, { "created": "Tue, 17 Mar 2009 16:47:49 GMT", "version": "v2" } ]
2009-08-19
[ [ "Dumitru", "Adrian", "" ], [ "Guo", "Yun", "" ], [ "Mocsy", "Agnes", "" ], [ "Strickland", "Michael", "" ] ]
We consider quarkonium in a hot QCD plasma which, due to expansion and non-zero viscosity, exhibits a local anisotropy in momentum space. At short distances the heavy-quark potential is known at tree level from the hard-thermal loop resummed gluon propagator in anisotropic perturbative QCD. The potential at long distances is modeled as a QCD string which is screened at the same scale as the Coulomb field. At asymptotic separation the potential energy is non-zero and inversely proportional to the temperature. We obtain numerical solutions of the three-dimensional Schroedinger equation for this potential. We find that quarkonium binding is stronger at non-vanishing viscosity and expansion rate, and that the anisotropy leads to polarization of the P-wave states.
1811.12764
Alexandre Arbey
A. Arbey, J. Ellis, F. Mahmoudi, G. Robbins
Dark matter and the early Universe
4 pages, 2 figures, contribution to the proceedings of the 39th International Conference on High Energy Physics (ICHEP2018), Seoul, 4-11 July 2018
PoS ICHEP2018 (2018) 035
null
CERN-TH-2018-248
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Big-Bang nucleosynthesis (BBN) represents one of the earliest phenomena that can lead to observational constraints on the early Universe properties. It is well-known that many important mechanisms and phase transitions occurred before BBN. We discuss the possibility of gaining insight into the primordial Universe through studies of dark matter in cosmology, astroparticle physics and colliders. For this purpose, we assume that dark matter is a thermal relic, and show that combining collider searches with dark matter observables can lead to strong constraints on the period of freeze-out before BBN.
[ { "created": "Fri, 30 Nov 2018 12:43:39 GMT", "version": "v1" } ]
2018-12-03
[ [ "Arbey", "A.", "" ], [ "Ellis", "J.", "" ], [ "Mahmoudi", "F.", "" ], [ "Robbins", "G.", "" ] ]
Big-Bang nucleosynthesis (BBN) represents one of the earliest phenomena that can lead to observational constraints on the early Universe properties. It is well-known that many important mechanisms and phase transitions occurred before BBN. We discuss the possibility of gaining insight into the primordial Universe through studies of dark matter in cosmology, astroparticle physics and colliders. For this purpose, we assume that dark matter is a thermal relic, and show that combining collider searches with dark matter observables can lead to strong constraints on the period of freeze-out before BBN.
2106.10748
Lin Zhang
Lin Zhang, Chutian Chen, Yidian Chen, Mei Huang
Spectra of glueballs and oddballs and the equation of state from holographic QCD
null
null
10.1103/PhysRevD.105.026020
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the spectra of two-gluon glueballs and three-gluon oddballs and corresponding equation of state in $5$-dimensional deformed holographic QCD models in the graviton-dilaton system, where the metric, the dilaton field and dilaton potential are self-consistently solved from each other through the Einstein field equations and the equation of motion of the dilaton field. We compare the models by inputting the dilaton field, inputting the deformed metric and inputting the dilaton potential, and find that with only 2 parameters, the $5$-dimensional holographic QCD model predictions on glueballs/oddballs spectra in general are in good agreement with lattice results except two oddballs $0^{+-}$ and $2^{+-}$. From the results of glueballs/oddballs spectra at zero temperature and the equation of state at finite temperature, we observe that the model with quadratic dilaton field can simultaneously describe glueballs/oddballs spectra as well as equation of state of pure gluon system. The model with quadratic $A_{E}(z)$ can describe glueballs/oddballs spectra, but its corresponding equation of state behaves more like $N_{f}=2+1$ quark matter. These are consistent with dimension analysis at UV boundary.
[ { "created": "Sun, 20 Jun 2021 20:36:34 GMT", "version": "v1" }, { "created": "Wed, 14 Jul 2021 00:50:54 GMT", "version": "v2" } ]
2022-02-02
[ [ "Zhang", "Lin", "" ], [ "Chen", "Chutian", "" ], [ "Chen", "Yidian", "" ], [ "Huang", "Mei", "" ] ]
We study the spectra of two-gluon glueballs and three-gluon oddballs and corresponding equation of state in $5$-dimensional deformed holographic QCD models in the graviton-dilaton system, where the metric, the dilaton field and dilaton potential are self-consistently solved from each other through the Einstein field equations and the equation of motion of the dilaton field. We compare the models by inputting the dilaton field, inputting the deformed metric and inputting the dilaton potential, and find that with only 2 parameters, the $5$-dimensional holographic QCD model predictions on glueballs/oddballs spectra in general are in good agreement with lattice results except two oddballs $0^{+-}$ and $2^{+-}$. From the results of glueballs/oddballs spectra at zero temperature and the equation of state at finite temperature, we observe that the model with quadratic dilaton field can simultaneously describe glueballs/oddballs spectra as well as equation of state of pure gluon system. The model with quadratic $A_{E}(z)$ can describe glueballs/oddballs spectra, but its corresponding equation of state behaves more like $N_{f}=2+1$ quark matter. These are consistent with dimension analysis at UV boundary.
1310.2190
Qian Wang
Martin Cleven, Qian Wang, Feng-Kun Guo, Christoph Hanhart, Ulf-G. Mei{\ss}ner, and Qiang Zhao
$Y(4260)$ as the first $S$-wave open charm vector molecular state?
Analysis of the angular distribution is included which can be compared with the experimental data
null
10.1103/PhysRevD.90.074039
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Since its first observation in 2005, the vector charmonium $Y(4260)$ has turned out to be one of the prime candidates for an exotic state in the charmonium spectrum. It was recently proposed that the $Y(4260)$ should have a prominent $D_1\bar{D}+c.c.$ molecular component that is strongly correlated with the production of the charged $Z_c(3900)$. In this paper we demonstrate that the nontrivial cross section line shapes of $e^+e^-\to J/\psi\pi\pi$ and $h_c\pi\pi$ can be naturally explained by the molecular scenario. As a consequence we find a significantly smaller mass for the $Y(4260)$ than previous studied. In the $e^+e^-\to \bar D D^*\pi+c.c.$ process, with the inclusion of an additional $S$-wave $\bar D^*\pi$ contribution constrained from data on the $D\bar D^*$ invariant mass distribution, we obtain a good agreement with the data of the angular distributions. We also predict an unusual line shape of $Y(4260)$ in this channel that may serve as a smoking gun for a predominantly molecular nature of $Y(4260)$. Improved measurements of these observables are therefore crucial for a better understanding of the structure of this famous resonance.
[ { "created": "Tue, 8 Oct 2013 16:10:39 GMT", "version": "v1" }, { "created": "Sun, 15 Jun 2014 09:44:47 GMT", "version": "v2" } ]
2015-06-17
[ [ "Cleven", "Martin", "" ], [ "Wang", "Qian", "" ], [ "Guo", "Feng-Kun", "" ], [ "Hanhart", "Christoph", "" ], [ "Meißner", "Ulf-G.", "" ], [ "Zhao", "Qiang", "" ] ]
Since its first observation in 2005, the vector charmonium $Y(4260)$ has turned out to be one of the prime candidates for an exotic state in the charmonium spectrum. It was recently proposed that the $Y(4260)$ should have a prominent $D_1\bar{D}+c.c.$ molecular component that is strongly correlated with the production of the charged $Z_c(3900)$. In this paper we demonstrate that the nontrivial cross section line shapes of $e^+e^-\to J/\psi\pi\pi$ and $h_c\pi\pi$ can be naturally explained by the molecular scenario. As a consequence we find a significantly smaller mass for the $Y(4260)$ than previous studied. In the $e^+e^-\to \bar D D^*\pi+c.c.$ process, with the inclusion of an additional $S$-wave $\bar D^*\pi$ contribution constrained from data on the $D\bar D^*$ invariant mass distribution, we obtain a good agreement with the data of the angular distributions. We also predict an unusual line shape of $Y(4260)$ in this channel that may serve as a smoking gun for a predominantly molecular nature of $Y(4260)$. Improved measurements of these observables are therefore crucial for a better understanding of the structure of this famous resonance.
2301.00827
Zhengkang Zhang
Timothy Cohen, Xiaochuan Lu, Zhengkang Zhang
Anomaly Cancellation in Effective Field Theories From the Covariant Derivative Expansion
21 pages
null
null
CERN-TH-2023-002
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend our recently-proposed formalism for calculating anomalies of global and gauge symmetries using the Covariant Derivative Expansion to include a general class of operators that can appear in relativistic Effective Field Theories (EFTs). This allows us to prove that EFT operators involving general scalar, vector, and tensor couplings to fermion bilinears only give rise to irrelevant anomalies, which can be removed by an appropriate choice of counterterms, thereby confirming the absence of new constraints from anomaly cancellation on the Standard Model EFT.
[ { "created": "Mon, 2 Jan 2023 19:00:03 GMT", "version": "v1" } ]
2023-01-04
[ [ "Cohen", "Timothy", "" ], [ "Lu", "Xiaochuan", "" ], [ "Zhang", "Zhengkang", "" ] ]
We extend our recently-proposed formalism for calculating anomalies of global and gauge symmetries using the Covariant Derivative Expansion to include a general class of operators that can appear in relativistic Effective Field Theories (EFTs). This allows us to prove that EFT operators involving general scalar, vector, and tensor couplings to fermion bilinears only give rise to irrelevant anomalies, which can be removed by an appropriate choice of counterterms, thereby confirming the absence of new constraints from anomaly cancellation on the Standard Model EFT.
0907.0276
Guido Montagna Dr
G. Balossini, C.M. Carloni Calame, G. Montagna, M. Moretti, O. Nicrosini, F. Piccinini, M. Treccani and A. Vicini
Combination of electroweak and QCD corrections to single W production at the Fermilab Tevatron and the CERN LHC
One reference added. Final version to appear in JHEP
JHEP 1001:013,2010
10.1007/JHEP01(2010)013
FNT/T 2009/02, SHEP-09-14, IFUM-942-FT
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Precision studies of the production of a high-transverse momentum lepton in association with missing energy at hadron colliders require that electroweak and QCD higher-order contributions are simultaneously taken into account in theoretical predictions and data analysis. Here we present a detailed phenomenological study of the impact of electroweak and strong contributions, as well as of their combination, to all the observables relevant for the various facets of the $p\smartpap \to {\rm lepton} + X$ physics programme at hadron colliders, including luminosity monitoring and Parton Distribution Functions constraint, $W$ precision physics and search for new physics signals. We provide a theoretical recipe to carefully combine electroweak and strong corrections, that are mandatory in view of the challenging experimental accuracy already reached at the Fermilab Tevatron and aimed at the CERN LHC, and discuss the uncertainty inherent the combination. We conclude that the theoretical accuracy of our calculation can be conservatively estimated to be about 2% for standard event selections at the Tevatron and the LHC, and about 5% in the very high $W$ transverse mass/lepton transverse momentum tails. We also provide arguments for a more aggressive error estimate (about 1% and 3%, respectively) and conclude that in order to attain a one per cent accuracy: 1) exact mixed ${\cal O}(\alpha \alpha_s)$ corrections should be computed in addition to the already available NNLO QCD contributions and two-loop electroweak Sudakov logarithms; 2) QCD and electroweak corrections should be coherently included into a single event generator.
[ { "created": "Thu, 2 Jul 2009 15:00:40 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 2009 13:11:54 GMT", "version": "v2" }, { "created": "Tue, 22 Dec 2009 17:26:40 GMT", "version": "v3" } ]
2010-01-22
[ [ "Balossini", "G.", "" ], [ "Calame", "C. M. Carloni", "" ], [ "Montagna", "G.", "" ], [ "Moretti", "M.", "" ], [ "Nicrosini", "O.", "" ], [ "Piccinini", "F.", "" ], [ "Treccani", "M.", "" ], [ "Vicini", "A.", "" ] ]
Precision studies of the production of a high-transverse momentum lepton in association with missing energy at hadron colliders require that electroweak and QCD higher-order contributions are simultaneously taken into account in theoretical predictions and data analysis. Here we present a detailed phenomenological study of the impact of electroweak and strong contributions, as well as of their combination, to all the observables relevant for the various facets of the $p\smartpap \to {\rm lepton} + X$ physics programme at hadron colliders, including luminosity monitoring and Parton Distribution Functions constraint, $W$ precision physics and search for new physics signals. We provide a theoretical recipe to carefully combine electroweak and strong corrections, that are mandatory in view of the challenging experimental accuracy already reached at the Fermilab Tevatron and aimed at the CERN LHC, and discuss the uncertainty inherent the combination. We conclude that the theoretical accuracy of our calculation can be conservatively estimated to be about 2% for standard event selections at the Tevatron and the LHC, and about 5% in the very high $W$ transverse mass/lepton transverse momentum tails. We also provide arguments for a more aggressive error estimate (about 1% and 3%, respectively) and conclude that in order to attain a one per cent accuracy: 1) exact mixed ${\cal O}(\alpha \alpha_s)$ corrections should be computed in addition to the already available NNLO QCD contributions and two-loop electroweak Sudakov logarithms; 2) QCD and electroweak corrections should be coherently included into a single event generator.
1008.2206
Jamie Tattersall Mr
Gudrid Moortgat-Pick, Krzysztof Rolbiecki, Jamie Tattersall
Momentum reconstruction at the LHC for probing CP-violation in the stop sector
Version published in Phys.Rev. D83 (2011) 115012
Phys.Rev.D83:115012,2011
10.1103/PhysRevD.83.115012
DCPT-10-126, DESY 10-094, IPPP-10-63
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the potential to observe CP-violating effects in SUSY stop cascade decay chains at the LHC. Asymmetries composed by triple products of momenta of the final state particles are sensitive to CP-violating effects. Due to large boosts that dilute the asymmetries, these can be difficult to observe. If all particle masses in a cascade decay are known, it may be possible to reconstruct all momenta in the decay chains on an event-by-event basis even when we have missing momentum due to a stable LSP. After the reconstruction, the non-diluted CP-violating signal can be recovered and gets significantly enhanced so that an observation may become feasible. A fully hadronic study has been completed to define the areas of the mSUGRA parameter space that may yield a 3-sigma observation with 500 fb^(-1) at the LHC.
[ { "created": "Thu, 12 Aug 2010 20:01:05 GMT", "version": "v1" }, { "created": "Thu, 21 Jul 2011 12:44:47 GMT", "version": "v2" } ]
2011-07-22
[ [ "Moortgat-Pick", "Gudrid", "" ], [ "Rolbiecki", "Krzysztof", "" ], [ "Tattersall", "Jamie", "" ] ]
We study the potential to observe CP-violating effects in SUSY stop cascade decay chains at the LHC. Asymmetries composed by triple products of momenta of the final state particles are sensitive to CP-violating effects. Due to large boosts that dilute the asymmetries, these can be difficult to observe. If all particle masses in a cascade decay are known, it may be possible to reconstruct all momenta in the decay chains on an event-by-event basis even when we have missing momentum due to a stable LSP. After the reconstruction, the non-diluted CP-violating signal can be recovered and gets significantly enhanced so that an observation may become feasible. A fully hadronic study has been completed to define the areas of the mSUGRA parameter space that may yield a 3-sigma observation with 500 fb^(-1) at the LHC.
hep-ph/0008189
Scott Willenbrock
S. Willenbrock (U. of Illinois)
Studying the Top Quark
17 pages, LateX, 10 figures. One reference added. To appear in Reviews of Modern Physics
Rev.Mod.Phys.72:1141-1148,2000
10.1103/RevModPhys.72.1141
null
hep-ph hep-ex
null
The top quark, discovered at the Fermilab Tevatron collider in 1995, is the heaviest known elementary particle. Its large mass suggests that it may play a special role in nature. It behaves differently from the other known quarks due both to its large mass and its short lifetime. Thus far we have only crude measurements of the properties of the top quark, such as its mass, weak interactions, strong interactions, and decay modes. These measurements will be made more precise when the Tevatron begins operation again in 2001. I review the present status of these measurements, and discuss their anticipated improvement.
[ { "created": "Thu, 17 Aug 2000 17:01:36 GMT", "version": "v1" }, { "created": "Mon, 4 Sep 2000 18:29:18 GMT", "version": "v2" } ]
2008-11-26
[ [ "Willenbrock", "S.", "", "U. of Illinois" ] ]
The top quark, discovered at the Fermilab Tevatron collider in 1995, is the heaviest known elementary particle. Its large mass suggests that it may play a special role in nature. It behaves differently from the other known quarks due both to its large mass and its short lifetime. Thus far we have only crude measurements of the properties of the top quark, such as its mass, weak interactions, strong interactions, and decay modes. These measurements will be made more precise when the Tevatron begins operation again in 2001. I review the present status of these measurements, and discuss their anticipated improvement.
2307.05348
Abinash Medhi
Abinash Medhi, Arnab Sarker, and Moon Moon Devi
Scalar NSI: A unique tool for constraining absolute neutrino masses via $\nu$-oscillations
8 pages, 5 figures, 3 tables
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In the standard interaction scenario, a direct measurement of absolute neutrino masses via neutrino oscillations is not feasible, as the oscillations depend only on the mass-squared differences. However, the presence of scalar non-standard interactions can introduce sub-dominant terms in the oscillation Hamiltonian that can directly affect the neutrino mass matrix and thereby making scalar NSI a unique tool for neutrino mass measurements. In this work, for the first time, we constrain the absolute masses of neutrinos by probing scalar NSI. We show that a bound on the lightest neutrino mass can be induced in the presence of scalar NSI at DUNE. We find that the lightest neutrino mass can be best constrained with $\eta_{\tau\tau}$ and $\eta_{\mu\mu}$ at $2\sigma$ C.L. for normal and inverted hierarchy respectively. This study suggests that scalar NSI can serve as an interesting avenue to constrain the absolute neutrino masses in long-baseline neutrino experiments via neutrino oscillations.
[ { "created": "Tue, 11 Jul 2023 15:36:33 GMT", "version": "v1" } ]
2023-07-12
[ [ "Medhi", "Abinash", "" ], [ "Sarker", "Arnab", "" ], [ "Devi", "Moon Moon", "" ] ]
In the standard interaction scenario, a direct measurement of absolute neutrino masses via neutrino oscillations is not feasible, as the oscillations depend only on the mass-squared differences. However, the presence of scalar non-standard interactions can introduce sub-dominant terms in the oscillation Hamiltonian that can directly affect the neutrino mass matrix and thereby making scalar NSI a unique tool for neutrino mass measurements. In this work, for the first time, we constrain the absolute masses of neutrinos by probing scalar NSI. We show that a bound on the lightest neutrino mass can be induced in the presence of scalar NSI at DUNE. We find that the lightest neutrino mass can be best constrained with $\eta_{\tau\tau}$ and $\eta_{\mu\mu}$ at $2\sigma$ C.L. for normal and inverted hierarchy respectively. This study suggests that scalar NSI can serve as an interesting avenue to constrain the absolute neutrino masses in long-baseline neutrino experiments via neutrino oscillations.
1906.02693
Patrick Janot
Alain Blondel, Patrick Janot, Niloufar Alipour Tehrani, Patrizia Azzi, Paolo Azzurri, Nicola Bacchetta, Michael Benedikt, Freya Blekman, Manuela Boscolo, Mogens Dam, Stefania De Curtis, David d'Enterria, John Ellis, Gerardo Ganis, Janusz Gluza, Cl\'ement Helsens, Staszek Jadach, Mike Koratzinos, Markus Klute, Christos Leonidopoulos, Elizabeth Locci, Michelangelo Mangano, St\'ephane Monteil, Katsunobu Oide, Vitaly Okorokov, Emmanuel Perez, Tord Riemann, Roberto Tenchini, Michele Selvaggi, Georgios Voutsinas, J\"org Wenninger, Frank Zimmermann
FCC-ee: Your Questions Answered
Contribution to the European Particle Physics Strategy Update 2018-2020. Forty-five pages, six figures
null
null
null
hep-ph hep-ex physics.acc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This document answers in simple terms many FAQs about FCC-ee, including comparisons with other colliders. It complements the FCC-ee CDR and the FCC Physics CDR by addressing many questions from non-experts and clarifying issues raised during the European Strategy symposium in Granada, with a view to informing discussions in the period between now and the final endorsement by the CERN Council in 2020 of the European Strategy Group recommendations. This document will be regularly updated as more questions appear or new information becomes available.
[ { "created": "Thu, 6 Jun 2019 16:43:21 GMT", "version": "v1" } ]
2019-06-07
[ [ "Blondel", "Alain", "" ], [ "Janot", "Patrick", "" ], [ "Tehrani", "Niloufar Alipour", "" ], [ "Azzi", "Patrizia", "" ], [ "Azzurri", "Paolo", "" ], [ "Bacchetta", "Nicola", "" ], [ "Benedikt", "Michael", "" ], [ "Blekman", "Freya", "" ], [ "Boscolo", "Manuela", "" ], [ "Dam", "Mogens", "" ], [ "De Curtis", "Stefania", "" ], [ "d'Enterria", "David", "" ], [ "Ellis", "John", "" ], [ "Ganis", "Gerardo", "" ], [ "Gluza", "Janusz", "" ], [ "Helsens", "Clément", "" ], [ "Jadach", "Staszek", "" ], [ "Koratzinos", "Mike", "" ], [ "Klute", "Markus", "" ], [ "Leonidopoulos", "Christos", "" ], [ "Locci", "Elizabeth", "" ], [ "Mangano", "Michelangelo", "" ], [ "Monteil", "Stéphane", "" ], [ "Oide", "Katsunobu", "" ], [ "Okorokov", "Vitaly", "" ], [ "Perez", "Emmanuel", "" ], [ "Riemann", "Tord", "" ], [ "Tenchini", "Roberto", "" ], [ "Selvaggi", "Michele", "" ], [ "Voutsinas", "Georgios", "" ], [ "Wenninger", "Jörg", "" ], [ "Zimmermann", "Frank", "" ] ]
This document answers in simple terms many FAQs about FCC-ee, including comparisons with other colliders. It complements the FCC-ee CDR and the FCC Physics CDR by addressing many questions from non-experts and clarifying issues raised during the European Strategy symposium in Granada, with a view to informing discussions in the period between now and the final endorsement by the CERN Council in 2020 of the European Strategy Group recommendations. This document will be regularly updated as more questions appear or new information becomes available.
hep-ph/9711490
Leonid Glozman
L.Ya. Glozman
Light and strange baryons, two-baryon systems and the chiral symmetry of QCD
10 pages, Invited talk given at International Conference on Hypernuclear and Strange Particle Physics (HYP97, Brookhaven National Laboratory, October 13-18, 1997, USA), to appear in Nuclear Physics A
Nucl.Phys. A639 (1998) 65c-74c
10.1016/S0375-9474(98)00252-8
null
hep-ph nucl-th
null
Beyond the scale of spontaneous breaking of chiral symmetry light and strange baryons should be considered as systems of three constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons between the constituent quarks. The flavor-spin structure and sign of the short-range part of the Goldstone boson exchange interaction reduces the $SU(6)_{FS}$ symmetry down to $SU(3)_F \times SU(2)_S$, induces hyperfine splittings and provides correct ordering of the lowest states with positive and negative parity. A unified description of light and strange baryon spectra calculated in a semirelativistic framework is presented. It is demonstrated that the same short-range part of the Goldstone boson exchange between the constituent quarks induces a strong short-range repulsion in $NN$ system when the latter is treated as $6Q$ system. Similar to the $NN$ system there should be a short-range repulsion in other $NY$ and $YY$ two-baryon systems. We also find that the compact 6Q system with the "H-particle" quantum numbers lies a few hundreds MeV above the $\Lambda\Lambda$ threshold. It then suggests that the deeply bound H-particle should not exist.
[ { "created": "Thu, 27 Nov 1997 10:59:32 GMT", "version": "v1" } ]
2009-10-30
[ [ "Glozman", "L. Ya.", "" ] ]
Beyond the scale of spontaneous breaking of chiral symmetry light and strange baryons should be considered as systems of three constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons between the constituent quarks. The flavor-spin structure and sign of the short-range part of the Goldstone boson exchange interaction reduces the $SU(6)_{FS}$ symmetry down to $SU(3)_F \times SU(2)_S$, induces hyperfine splittings and provides correct ordering of the lowest states with positive and negative parity. A unified description of light and strange baryon spectra calculated in a semirelativistic framework is presented. It is demonstrated that the same short-range part of the Goldstone boson exchange between the constituent quarks induces a strong short-range repulsion in $NN$ system when the latter is treated as $6Q$ system. Similar to the $NN$ system there should be a short-range repulsion in other $NY$ and $YY$ two-baryon systems. We also find that the compact 6Q system with the "H-particle" quantum numbers lies a few hundreds MeV above the $\Lambda\Lambda$ threshold. It then suggests that the deeply bound H-particle should not exist.
1811.01691
Michael Eides
Michael I. Eides and Victor Yu. Petrov
Decays of Pentaquarks in Hadrocharmonium and Molecular Pictures
33 pages, 14 figures; v2: minor editorial changes, version published in Phys. Rev. D
Phys. Rev. D 98, 114037 (2018)
10.1103/PhysRevD.98.114037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider decays of the hidden charm LHCb pentaquarks in the hadrocharmonium and molecular scenarios. In both pictures the LHCb pentaquarks are essentially nonrelativistic bound states. We develop a semirelativistic framework for calculation of the partial decay widths that allows the final particles to be relativistic. Using this approach we calculate the decay widths in the hadrocharmonium and molecular pictures. Molecular hidden charm pentaquarks are constructed as loosely bound states of charmed and anticharmed hadrons. Calculations show that molecular pentaquarks decay predominantly into states with open charm. Strong suppression of the molecular pentaquark decays into states with hidden charm is qualitatively explained by a relatively large size of the molecular pentaquark. The decay pattern of hadrocharmonium pentaquarks that are interpreted as loosely bound states of excited charmonium $\psi'$ and nucleons is quite different. This time dominate decays into states with hidden charm, but suppression of the decays with charm exchange is weaker than in the respective molecular case. The weaker suppression is explained by a larger binding energy and respectively smaller size of the hadrocharmonium pentaquarks. These results combined with the experimental data on partial decay widths could allow to figure out which of the two theoretical scenarios for pentaquarks (if either) is chosen by nature.
[ { "created": "Mon, 5 Nov 2018 14:04:35 GMT", "version": "v1" }, { "created": "Mon, 31 Dec 2018 15:58:08 GMT", "version": "v2" } ]
2019-01-02
[ [ "Eides", "Michael I.", "" ], [ "Petrov", "Victor Yu.", "" ] ]
We consider decays of the hidden charm LHCb pentaquarks in the hadrocharmonium and molecular scenarios. In both pictures the LHCb pentaquarks are essentially nonrelativistic bound states. We develop a semirelativistic framework for calculation of the partial decay widths that allows the final particles to be relativistic. Using this approach we calculate the decay widths in the hadrocharmonium and molecular pictures. Molecular hidden charm pentaquarks are constructed as loosely bound states of charmed and anticharmed hadrons. Calculations show that molecular pentaquarks decay predominantly into states with open charm. Strong suppression of the molecular pentaquark decays into states with hidden charm is qualitatively explained by a relatively large size of the molecular pentaquark. The decay pattern of hadrocharmonium pentaquarks that are interpreted as loosely bound states of excited charmonium $\psi'$ and nucleons is quite different. This time dominate decays into states with hidden charm, but suppression of the decays with charm exchange is weaker than in the respective molecular case. The weaker suppression is explained by a larger binding energy and respectively smaller size of the hadrocharmonium pentaquarks. These results combined with the experimental data on partial decay widths could allow to figure out which of the two theoretical scenarios for pentaquarks (if either) is chosen by nature.
hep-ph/0208151
Stefan Gieseke
Stefan Gieseke (Cambridge)
NLO corrections to the photon impact factor
4 pp, 4 figs, espcrc2.sty (included), Talk given at QCD '02, Montpellier, France, 2-9th July 2002
null
10.1016/S0920-5632(03)01809-7
Cavendish-HEP-02/12
hep-ph
null
We review the program of the calculation of next-to-leading order corrections to the virtual photon impact factor. Following a brief introduction we present some technical aspects for the various contributions. Recently obtained results for transversely polarised virtual photons are discussed and an outline of how infrared divergences are cancelled is given. Implications of the subtraction of leading energy logarithms are discussed.
[ { "created": "Thu, 15 Aug 2002 17:25:46 GMT", "version": "v1" } ]
2009-11-07
[ [ "Gieseke", "Stefan", "", "Cambridge" ] ]
We review the program of the calculation of next-to-leading order corrections to the virtual photon impact factor. Following a brief introduction we present some technical aspects for the various contributions. Recently obtained results for transversely polarised virtual photons are discussed and an outline of how infrared divergences are cancelled is given. Implications of the subtraction of leading energy logarithms are discussed.
1002.1289
Tobias Kleinschmidt
Wolfgang Kilian and Tobias Kleinschmidt
Using Feynman's Tree Theorem to Evaluate Loop Integrals Numerically
7 pages, 2 figures; Contribution to the 9th International Symposium on Radiative Corrections (RADCOR 2009), October 25-30 2009, Ascona, Switzerland
PoS(RADCOR2009)024
null
IPPP/10/01, DCPT/10/02, SI-HEP-2010-02
hep-ph
http://creativecommons.org/licenses/by-nc-sa/3.0/
We report on a new method for the numerical evaluation of loop integrals, based on the Feynman Tree Theorem. The loop integrals are replaced by phase-space integration over fictitious extra on-shell particles. This integration can be performed alongside with the Monte-Carlo integration of ordinary phase-space, directly leading to NLO event generation.
[ { "created": "Fri, 5 Feb 2010 18:06:20 GMT", "version": "v1" } ]
2010-02-08
[ [ "Kilian", "Wolfgang", "" ], [ "Kleinschmidt", "Tobias", "" ] ]
We report on a new method for the numerical evaluation of loop integrals, based on the Feynman Tree Theorem. The loop integrals are replaced by phase-space integration over fictitious extra on-shell particles. This integration can be performed alongside with the Monte-Carlo integration of ordinary phase-space, directly leading to NLO event generation.
1812.10832
Andreas Otto
A. Otto, D. Graeveling, B. K\"ampfer
Response of the QED(2) Vacuum to a Quench: Long-term Oscillations of the Electric Field and the Pair Creation Rate
6 pages, 3 figures
null
10.1088/1361-6587/ab1a21
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider -- within QED(2) -- the backreaction to the Schwinger pair creation in a time dependent, spatially homogeneous electric field. Our focus is the depletion of the external field as a quench and the subsequent long-term evolution of the resulting electric field. Our numerical solutions of the self consistent, fully backreacted dynamical equations exhibit a self-sustaining oscillation of both the electric field and the pair number depending on the coupling strength.
[ { "created": "Thu, 27 Dec 2018 21:39:09 GMT", "version": "v1" } ]
2019-06-26
[ [ "Otto", "A.", "" ], [ "Graeveling", "D.", "" ], [ "Kämpfer", "B.", "" ] ]
We consider -- within QED(2) -- the backreaction to the Schwinger pair creation in a time dependent, spatially homogeneous electric field. Our focus is the depletion of the external field as a quench and the subsequent long-term evolution of the resulting electric field. Our numerical solutions of the self consistent, fully backreacted dynamical equations exhibit a self-sustaining oscillation of both the electric field and the pair number depending on the coupling strength.
1804.01925
Shun Zhou
Zhi-zhong Xing, Shun Zhou
Naumov- and Toshev-like relations in the renormalization-group evolution of quarks and Dirac neutrinos
11 pages, 1 figure, more discussions added, to be published in Chin. Phys. C
Chin. Phys. C 42 (2018) 103105
10.1088/1674-1137/42/10/103105
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In an analytical way of studying matter effects on neutrino oscillations, the Naumov and Toshev relations have been derived to respectively link the Jarlskog invariant of CP violation and the Dirac phase in the standard parametrization of the $3\times 3$ flavor mixing matrix to their matter-corrected counterparts. Here we show that there exist similar relations for Dirac neutrinos and charged leptons evolving with energy scales via the one-loop renormalization-group (RG) equations in the tau-dominance approximation, and for the running behaviors of up- and down-type quarks in the top-dominance approximation, provided a different parametrization is taken into account.
[ { "created": "Thu, 5 Apr 2018 16:00:08 GMT", "version": "v1" }, { "created": "Wed, 22 Aug 2018 01:47:41 GMT", "version": "v2" } ]
2018-08-23
[ [ "Xing", "Zhi-zhong", "" ], [ "Zhou", "Shun", "" ] ]
In an analytical way of studying matter effects on neutrino oscillations, the Naumov and Toshev relations have been derived to respectively link the Jarlskog invariant of CP violation and the Dirac phase in the standard parametrization of the $3\times 3$ flavor mixing matrix to their matter-corrected counterparts. Here we show that there exist similar relations for Dirac neutrinos and charged leptons evolving with energy scales via the one-loop renormalization-group (RG) equations in the tau-dominance approximation, and for the running behaviors of up- and down-type quarks in the top-dominance approximation, provided a different parametrization is taken into account.
1910.01839
Ignasi Rosell
Ignasi Rosell, Claudius Krause, Antonio Pich and Juan Jos\'e Sanz-Cillero
Effective theories and resonances in strongly-coupled electroweak symmetry breaking scenarios
6 pages, 3 figures. Talk given at European Physical Society Conference on High Energy Physics (EPS-HEP2019), 10-17 July (2019), Ghent (Belgium)
null
null
IFIC/19-38, FTUV/19-1004, FERMILAB-CONF-19-479-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Due to the mass gap between the Standard Model and possible New Physics states, electroweak effective approaches are appropriate. Although a linear realization of the electroweak symmetry breaking with the Higgs forming a doublet together with the Goldstone bosons of the EWSB is a first possibility (SMEFT), we adopt the more general non-linear realization, where the Higgs is a singlet with independent couplings (EWET, HEFT or EWChL). We present the effective Lagrangian at low energies (the EWET, with only the SM fields) and at high energies (the resonance theory, with also a set of resonances). Taking into account the high scale of these resonances, their experimental searches seem to be more accessible by considering their imprints at low-energies, i.e., their imprints in the Low Energy Constants (LECs) of the EWET at energies lower than the resonance masses. We give some examples of these phenomenological connections.
[ { "created": "Fri, 4 Oct 2019 08:52:22 GMT", "version": "v1" } ]
2019-10-07
[ [ "Rosell", "Ignasi", "" ], [ "Krause", "Claudius", "" ], [ "Pich", "Antonio", "" ], [ "Sanz-Cillero", "Juan José", "" ] ]
Due to the mass gap between the Standard Model and possible New Physics states, electroweak effective approaches are appropriate. Although a linear realization of the electroweak symmetry breaking with the Higgs forming a doublet together with the Goldstone bosons of the EWSB is a first possibility (SMEFT), we adopt the more general non-linear realization, where the Higgs is a singlet with independent couplings (EWET, HEFT or EWChL). We present the effective Lagrangian at low energies (the EWET, with only the SM fields) and at high energies (the resonance theory, with also a set of resonances). Taking into account the high scale of these resonances, their experimental searches seem to be more accessible by considering their imprints at low-energies, i.e., their imprints in the Low Energy Constants (LECs) of the EWET at energies lower than the resonance masses. We give some examples of these phenomenological connections.
1409.3602
Sanjay Reddy
Dorota Grabowska, David B. Kaplan, Sanjay Reddy
The Role of the Electron Mass in Damping Chiral Magnetic Instability in Supernova and Neutron Stars
6 pages
Phys. Rev. D 91, 085035 (2015)
10.1103/PhysRevD.91.085035
INT-PUB-14-039
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the nonzero electron mass plays a critical role in determining the magnetic properties of neutron stars, making it impossible to generate the chiral charge density needed to trigger a strong chiral magnetic instability during the core collapse of supernovae. This instability has been proposed as a plausible mechanism for generating extremely large helical magnetic fields in neutron stars at their birth; the mechanism relies on the generation of a large non-equilibrium chiral charge density via electron capture reactions that selectively deplete left-handed electrons during core-collapse and the early evolution of the protoneutron star. Our calculation shows that the electron chirality violation rate induced by Rutherford scattering, despite being suppressed by the smallness of the electron mass relative to the electron chemical potential, is still fast compared to the weak interaction electron capture rate. The resulting asymmetry between right and left-handed electron densities is therefore never able to attain an astrophysically relevant magnitude.
[ { "created": "Thu, 11 Sep 2014 21:25:46 GMT", "version": "v1" } ]
2015-04-29
[ [ "Grabowska", "Dorota", "" ], [ "Kaplan", "David B.", "" ], [ "Reddy", "Sanjay", "" ] ]
We show that the nonzero electron mass plays a critical role in determining the magnetic properties of neutron stars, making it impossible to generate the chiral charge density needed to trigger a strong chiral magnetic instability during the core collapse of supernovae. This instability has been proposed as a plausible mechanism for generating extremely large helical magnetic fields in neutron stars at their birth; the mechanism relies on the generation of a large non-equilibrium chiral charge density via electron capture reactions that selectively deplete left-handed electrons during core-collapse and the early evolution of the protoneutron star. Our calculation shows that the electron chirality violation rate induced by Rutherford scattering, despite being suppressed by the smallness of the electron mass relative to the electron chemical potential, is still fast compared to the weak interaction electron capture rate. The resulting asymmetry between right and left-handed electron densities is therefore never able to attain an astrophysically relevant magnitude.
1906.05949
John Terry
Zhong-Bo Kang, Alexei Prokudin, Nobuo Sato, John Terry
Efficient Fourier Transforms for Transverse Momentum Dependent Distributions
17 pages, 7 figures
Comput. Phys. Commun. 258, 107611 (2021)
10.1016/j.cpc.2020.107611
JLAB-THY-19-2962
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hadron production at low transverse momenta in semi-inclusive deep inelastic scattering can be described by transverse momentum dependent (TMD) factorization. This formalism has also been widely used to study the Drell-Yan process and back-to-back hadron pair production in $e^+e^-$ collisions. These processes are the main ones for extractions of TMD parton distribution functions and TMD fragmentation functions, which encode important information about nucleon structure and hadronization. One of the most widely used TMD factorization formalism in phenomenology formulates TMD observables in coordinate $b_\perp$-space, the conjugate space of the transverse momentum. The Fourier transform from $b_\perp$-space back into transverse momentum space is sufficiently complicated due to oscillatory integrands that it requires a careful and computationally intensive numerical treatment in order to avoid potentially large numerical errors. Within the TMD formalism, the azimuthal angular dependence is analytically integrated and the two-dimensional $b_\perp$ integration reduces to a one-dimensional integration over the magnitude $b_\perp$. In this paper we develop a fast numerical Hankel transform algorithm for such a $b_\perp$-integration that improves the numerical accuracy of TMD calculations in all standard processes. Libraries for this algorithm are implemented in Python 2.7 and 3, C++, as well as FORTRAN77. All packages are made available open source.
[ { "created": "Thu, 13 Jun 2019 22:18:17 GMT", "version": "v1" }, { "created": "Sun, 20 Sep 2020 01:48:06 GMT", "version": "v2" } ]
2021-01-01
[ [ "Kang", "Zhong-Bo", "" ], [ "Prokudin", "Alexei", "" ], [ "Sato", "Nobuo", "" ], [ "Terry", "John", "" ] ]
Hadron production at low transverse momenta in semi-inclusive deep inelastic scattering can be described by transverse momentum dependent (TMD) factorization. This formalism has also been widely used to study the Drell-Yan process and back-to-back hadron pair production in $e^+e^-$ collisions. These processes are the main ones for extractions of TMD parton distribution functions and TMD fragmentation functions, which encode important information about nucleon structure and hadronization. One of the most widely used TMD factorization formalism in phenomenology formulates TMD observables in coordinate $b_\perp$-space, the conjugate space of the transverse momentum. The Fourier transform from $b_\perp$-space back into transverse momentum space is sufficiently complicated due to oscillatory integrands that it requires a careful and computationally intensive numerical treatment in order to avoid potentially large numerical errors. Within the TMD formalism, the azimuthal angular dependence is analytically integrated and the two-dimensional $b_\perp$ integration reduces to a one-dimensional integration over the magnitude $b_\perp$. In this paper we develop a fast numerical Hankel transform algorithm for such a $b_\perp$-integration that improves the numerical accuracy of TMD calculations in all standard processes. Libraries for this algorithm are implemented in Python 2.7 and 3, C++, as well as FORTRAN77. All packages are made available open source.
1512.01276
Hai-Yang Cheng
Hai-Yang Cheng, Chi-Yee Cheung, Guey-Lin Lin, Yeu-Chung Lin, Tung-Mow Yan, Hoi-Lai Yu
Heavy-Flavor-Conserving Hadronic Weak Decays of Heavy Baryons
11 pages, to appear in JHEP
null
10.1007/JHEP03(2016)028
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
More than two decades ago, we studied heavy-flavor-conserving weak decays of heavy baryons within the framework that incorporates both heavy-quark and chiral symmetries. In view of the first observation of $\Xi_b^-\to\Lambda_b^0\pi^-$ by LHCb recently, we have reexamined these decays and presented updated predictions. The predicted rates for $\Xi_b^-\to\Lambda_b^0\pi^-$ in the MIT bag and diquark models are consistent with experiment. The major theoretical uncertainty stems from the evaluation of baryon matrix elements. The branching fraction of $\Xi_c\to\Lambda_c\pi$ is predicted to be of order $10^{-4}$. It is suppressed relative to $Br(\Xi_b\to\Lambda_b\pi)$ owing to the shorter lifetime of $\Xi_c$ relative to $\Xi_b$ and the destructive nonspectator $W$-exchange contribution. The kinematically accessible weak decays of the sextet heavy baryon $\Omega_Q$ are $\Omega_Q\to\Xi_Q\pi$. Due to the absence of the $B_6-B_{\bar 3}$ transition in the heavy quark limit and the $B_6-B_6$ transition in the model calculations, $\Omega_Q\to\Xi_Q\pi$ vanish in the heavy quark limit.
[ { "created": "Thu, 3 Dec 2015 23:00:47 GMT", "version": "v1" }, { "created": "Sun, 21 Feb 2016 21:46:52 GMT", "version": "v2" } ]
2016-03-23
[ [ "Cheng", "Hai-Yang", "" ], [ "Cheung", "Chi-Yee", "" ], [ "Lin", "Guey-Lin", "" ], [ "Lin", "Yeu-Chung", "" ], [ "Yan", "Tung-Mow", "" ], [ "Yu", "Hoi-Lai", "" ] ]
More than two decades ago, we studied heavy-flavor-conserving weak decays of heavy baryons within the framework that incorporates both heavy-quark and chiral symmetries. In view of the first observation of $\Xi_b^-\to\Lambda_b^0\pi^-$ by LHCb recently, we have reexamined these decays and presented updated predictions. The predicted rates for $\Xi_b^-\to\Lambda_b^0\pi^-$ in the MIT bag and diquark models are consistent with experiment. The major theoretical uncertainty stems from the evaluation of baryon matrix elements. The branching fraction of $\Xi_c\to\Lambda_c\pi$ is predicted to be of order $10^{-4}$. It is suppressed relative to $Br(\Xi_b\to\Lambda_b\pi)$ owing to the shorter lifetime of $\Xi_c$ relative to $\Xi_b$ and the destructive nonspectator $W$-exchange contribution. The kinematically accessible weak decays of the sextet heavy baryon $\Omega_Q$ are $\Omega_Q\to\Xi_Q\pi$. Due to the absence of the $B_6-B_{\bar 3}$ transition in the heavy quark limit and the $B_6-B_6$ transition in the model calculations, $\Omega_Q\to\Xi_Q\pi$ vanish in the heavy quark limit.
2011.04666
Bryan Ostdiek
Forrest Flesher, Katherine Fraser, Charles Hutchison, Bryan Ostdiek, Matthew D. Schwartz
Parameter Inference from Event Ensembles and the Top-Quark Mass
v1: 27 + 5 pages, 14 + 3 figures. v2: Matches version accepted to JHEP
null
10.1007/JHEP09(2021)058
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the key tasks of any particle collider is measurement. In practice, this is often done by fitting data to a simulation, which depends on many parameters. Sometimes, when the effects of varying different parameters are highly correlated, a large ensemble of data may be needed to resolve parameter-space degeneracies. An important example is measuring the top-quark mass, where other physical and unphysical parameters in the simulation must be marginalized over when fitting the top-quark mass parameter. We compare three different methodologies for top-quark mass measurement: a classical histogram fitting procedure, similar to one commonly used in experiment optionally augmented with soft-drop jet grooming; a machine-learning method called DCTR; and a linear regression approach, either using a least-squares fit or with a dense linearly-activated neural network. Despite the fact that individual events are totally uncorrelated, we find that the linear regression methods work most effectively when we input an ensemble of events sorted by mass, rather than training them on individual events. Although all methods provide robust extraction of the top-quark mass parameter, the linear network does marginally best and is remarkably simple. For the top study, we conclude that the Monte-Carlo-based uncertainty on current extractions of the top-quark mass from LHC data can be reduced significantly (by perhaps a factor of 2) using networks trained on sorted event ensembles. More generally, machine learning from ensembles for parameter estimation has broad potential for collider physics measurements.
[ { "created": "Mon, 9 Nov 2020 19:00:01 GMT", "version": "v1" }, { "created": "Fri, 8 Oct 2021 19:21:52 GMT", "version": "v2" } ]
2021-10-12
[ [ "Flesher", "Forrest", "" ], [ "Fraser", "Katherine", "" ], [ "Hutchison", "Charles", "" ], [ "Ostdiek", "Bryan", "" ], [ "Schwartz", "Matthew D.", "" ] ]
One of the key tasks of any particle collider is measurement. In practice, this is often done by fitting data to a simulation, which depends on many parameters. Sometimes, when the effects of varying different parameters are highly correlated, a large ensemble of data may be needed to resolve parameter-space degeneracies. An important example is measuring the top-quark mass, where other physical and unphysical parameters in the simulation must be marginalized over when fitting the top-quark mass parameter. We compare three different methodologies for top-quark mass measurement: a classical histogram fitting procedure, similar to one commonly used in experiment optionally augmented with soft-drop jet grooming; a machine-learning method called DCTR; and a linear regression approach, either using a least-squares fit or with a dense linearly-activated neural network. Despite the fact that individual events are totally uncorrelated, we find that the linear regression methods work most effectively when we input an ensemble of events sorted by mass, rather than training them on individual events. Although all methods provide robust extraction of the top-quark mass parameter, the linear network does marginally best and is remarkably simple. For the top study, we conclude that the Monte-Carlo-based uncertainty on current extractions of the top-quark mass from LHC data can be reduced significantly (by perhaps a factor of 2) using networks trained on sorted event ensembles. More generally, machine learning from ensembles for parameter estimation has broad potential for collider physics measurements.
2003.11396
Yutaro Shoji
Hiroshi Okada and Yutaro Shoji
Dirac dark matter in a radiative neutrino model
19 pages, 5 figures; published version
null
null
APCTP Pre2020-004
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple radiative neutrino mass scenario with a Dirac dark matter candidate, which is minimally realized by a Z3 symmetry. We introduce two Dirac neutrinos and two inert doublets. We demonstrate that the model has a large allowed region that satisfies the constraints from neutrino oscillation data, lepton flavor violations, direct/indirect detection of dark matter and dark matter relic density. We also propose an efficient parameterization of the neutrino Yukawa couplings, which reproduces a desired active neutrino mass matrix.
[ { "created": "Wed, 25 Mar 2020 13:29:39 GMT", "version": "v1" }, { "created": "Sat, 31 Oct 2020 12:50:52 GMT", "version": "v2" } ]
2020-11-03
[ [ "Okada", "Hiroshi", "" ], [ "Shoji", "Yutaro", "" ] ]
We propose a simple radiative neutrino mass scenario with a Dirac dark matter candidate, which is minimally realized by a Z3 symmetry. We introduce two Dirac neutrinos and two inert doublets. We demonstrate that the model has a large allowed region that satisfies the constraints from neutrino oscillation data, lepton flavor violations, direct/indirect detection of dark matter and dark matter relic density. We also propose an efficient parameterization of the neutrino Yukawa couplings, which reproduces a desired active neutrino mass matrix.
hep-ph/0209141
Loic Grandchamp
L. Grandchamp and R. Rapp
Two-Component Approach to $J/\Psi$ Production in High-Energy Heavy-Ion Collisions
4 pages (incl. 4 postscript figures); v2: Typos corrected; uses espcrc1.sty. Talk given at Quark Matter 2002, Nantes, July 18-24, 2002, to appear in the proceedings in Nucl. Phys. A
Nucl.Phys. A715 (2003) 545-548
10.1016/S0375-9474(02)01512-9
null
hep-ph nucl-th
null
The production of charmonia in ultrarelativistic heavy-ion collisions is investigated including two sources. These are a primordial contribution coupled with various phases of dissociation, and a statistical coalescence of $c$ and $\bar{c}$ quarks at the hadronization phase transition. Within a schematic fireball evolution, SPS data on $J/\Psi$ production can be reasonably well reproduced. Remaining discrepancies in the $\Psi'/\Psi$ ratio are discussed. Predictions for the $J/\Psi$ centrality dependence at RHIC energies are confronted with first data from PHENIX. The pertinent excitation function of the $N_{J/\Psi}/N_{c\bar{c}}$ ratio exhibits a characteristic minimum structure signaling the transition from the standard $J/\Psi$ suppression scenario (SPS) to predominantly statistical production (RHIC).
[ { "created": "Thu, 12 Sep 2002 19:31:30 GMT", "version": "v1" }, { "created": "Wed, 18 Sep 2002 14:39:35 GMT", "version": "v2" } ]
2009-11-07
[ [ "Grandchamp", "L.", "" ], [ "Rapp", "R.", "" ] ]
The production of charmonia in ultrarelativistic heavy-ion collisions is investigated including two sources. These are a primordial contribution coupled with various phases of dissociation, and a statistical coalescence of $c$ and $\bar{c}$ quarks at the hadronization phase transition. Within a schematic fireball evolution, SPS data on $J/\Psi$ production can be reasonably well reproduced. Remaining discrepancies in the $\Psi'/\Psi$ ratio are discussed. Predictions for the $J/\Psi$ centrality dependence at RHIC energies are confronted with first data from PHENIX. The pertinent excitation function of the $N_{J/\Psi}/N_{c\bar{c}}$ ratio exhibits a characteristic minimum structure signaling the transition from the standard $J/\Psi$ suppression scenario (SPS) to predominantly statistical production (RHIC).
1303.1200
Matthew Baumgart
Matthew Baumgart, Brock Tweedie
Transverse Top Quark Polarization and the ttbar Forward-Backward Asymmetry
28 pages, 6 figures. v2: expanded discussion of constraints
null
10.1007/JHEP08(2013)072
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The forward-backward asymmetry in top pair production at the Tevatron has long been in tension with the Standard Model prediction. One of the only viable new physics scenarios capable of explaining this anomaly is an s-channel axigluon-like resonance, with the quantum numbers of the gluon but with significant axial couplings to quarks. While such a resonance can lead to a clear bump or excess in the ttbar or dijet mass spectra, it may also simply be too broad to cleanly observe. Here, we point out that broad ttbar resonances generally lead to net top and antitop polarizations transverse to the production plane. This polarization is consistent with all discrete spacetime symmetries, and, analogous to the forward-backward asymmetry itself, is absent in QCD at leading order. Within the parameter space consistent with the asymmetry measurements, the induced polarization can be sizable, and might be observable at the Tevatron or the LHC.
[ { "created": "Tue, 5 Mar 2013 22:08:32 GMT", "version": "v1" }, { "created": "Wed, 3 Jul 2013 02:50:56 GMT", "version": "v2" } ]
2015-06-15
[ [ "Baumgart", "Matthew", "" ], [ "Tweedie", "Brock", "" ] ]
The forward-backward asymmetry in top pair production at the Tevatron has long been in tension with the Standard Model prediction. One of the only viable new physics scenarios capable of explaining this anomaly is an s-channel axigluon-like resonance, with the quantum numbers of the gluon but with significant axial couplings to quarks. While such a resonance can lead to a clear bump or excess in the ttbar or dijet mass spectra, it may also simply be too broad to cleanly observe. Here, we point out that broad ttbar resonances generally lead to net top and antitop polarizations transverse to the production plane. This polarization is consistent with all discrete spacetime symmetries, and, analogous to the forward-backward asymmetry itself, is absent in QCD at leading order. Within the parameter space consistent with the asymmetry measurements, the induced polarization can be sizable, and might be observable at the Tevatron or the LHC.
hep-ph/0405255
Dominik Stockinger
Sven Heinemeyer, Dominik St\"ockinger, Georg Weiglein
Electroweak and supersymmetric two-loop corrections to (g-2)_\mu
23 pages, 9 figures
Nucl.Phys. B699 (2004) 103-123
10.1016/j.nuclphysb.2004.08.014
CERN-PH-TH/2004-094, DCPT/04/44, IPPP/04/22
hep-ph
null
We present the up to now most precise evaluation of electroweak and supersymmetric contributions to the anomalous magnetic moment of the muon \amu, describing in detail also the calculational techniques. We calculate the bosonic two-loop contributions in the Standard Model without the approximation of a heavy Higgs-boson mass, finding corrections up to 0.2*10^{-10} for a light Higgs boson. In the Minimal Supersymmetric Standard Model the corresponding two-loop contributions from the two-Higgs-doublet model part differ from the Standard Model result by up to 0.3*10^{-10}. Finally, we evaluate the diagrams where a loop of charginos or neutralinos, the superpartners of gauge and Higgs bosons, is inserted into a two-Higgs-doublet one-loop diagram. These corrections can amount up to 10*10^{-10}, which is almost 2\sigma of the current experimental uncertainty.
[ { "created": "Tue, 25 May 2004 17:04:36 GMT", "version": "v1" } ]
2009-11-10
[ [ "Heinemeyer", "Sven", "" ], [ "Stöckinger", "Dominik", "" ], [ "Weiglein", "Georg", "" ] ]
We present the up to now most precise evaluation of electroweak and supersymmetric contributions to the anomalous magnetic moment of the muon \amu, describing in detail also the calculational techniques. We calculate the bosonic two-loop contributions in the Standard Model without the approximation of a heavy Higgs-boson mass, finding corrections up to 0.2*10^{-10} for a light Higgs boson. In the Minimal Supersymmetric Standard Model the corresponding two-loop contributions from the two-Higgs-doublet model part differ from the Standard Model result by up to 0.3*10^{-10}. Finally, we evaluate the diagrams where a loop of charginos or neutralinos, the superpartners of gauge and Higgs bosons, is inserted into a two-Higgs-doublet one-loop diagram. These corrections can amount up to 10*10^{-10}, which is almost 2\sigma of the current experimental uncertainty.
1912.09940
Sokratis Trifinopoulos
Gino Isidori and Sokratis Trifinopoulos
Exploring the flavour structure of the high-scale MSSM
15 pages, 6 figures
null
10.1140/epjc/s10052-020-7821-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse the sensitivity of quark flavour-changing observables to the MSSM, in a regime of heavy superpartner masses. We analyse four distinct and motivated frameworks characterising the structure of the soft-breaking terms by means of approximate flavour symmetries. We show that a set of six low-energy observables with realistic chances of improvement in the near future, namely $\Delta M_{s,d}$, $\epsilon_K$, $\epsilon_K'/\epsilon_K$, $\mathcal{B} (K\to \pi\nu\bar\nu)$, and the phase of $D$--$\bar D$ mixing, could play a very important role in charactering these frameworks in a regime of superpartner masses up to $\mathcal{O}(100)$~TeV. We show that these observables remain very interesting even in a long-term perspective, i.e.~even taking into account the direct mass reach of the most ambitious future high-energy colliders.
[ { "created": "Fri, 20 Dec 2019 17:02:10 GMT", "version": "v1" } ]
2020-04-22
[ [ "Isidori", "Gino", "" ], [ "Trifinopoulos", "Sokratis", "" ] ]
We analyse the sensitivity of quark flavour-changing observables to the MSSM, in a regime of heavy superpartner masses. We analyse four distinct and motivated frameworks characterising the structure of the soft-breaking terms by means of approximate flavour symmetries. We show that a set of six low-energy observables with realistic chances of improvement in the near future, namely $\Delta M_{s,d}$, $\epsilon_K$, $\epsilon_K'/\epsilon_K$, $\mathcal{B} (K\to \pi\nu\bar\nu)$, and the phase of $D$--$\bar D$ mixing, could play a very important role in charactering these frameworks in a regime of superpartner masses up to $\mathcal{O}(100)$~TeV. We show that these observables remain very interesting even in a long-term perspective, i.e.~even taking into account the direct mass reach of the most ambitious future high-energy colliders.
1109.6786
Kazuhiro Tanaka
Tetsuo Nishikawa (1), Kazuhiro Tanaka (2) ((1) Ryotokuji Univ., (2) Juntendo Univ.)
QCD sum rules for quark-gluon three-body components in the B meson
28 pages, 20 figures, version to appear in Nuclear Physics B
null
null
J-PARC-TH-0032
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the QCD sum rule calculation of the heavy-quark effective theory parameters, $\lambda_E$ and $\lambda_H$, which correspond to matrix elements representing quark-gluon three-body components in the $B$-meson wavefunction. We derive the sum rules for $\lambda_{E,H}$ calculating the new higher-order QCD corrections, i.e., the order $\alpha_s$ radiative corrections to the Wilson coefficients associated with the dimension-5 quark-gluon mixed condensates, and the power corrections due to the dimension-6 vacuum condensates. We find that the new radiative corrections significantly improve the stability of the corresponding Borel sum rules and lead to the reduction of the values of $\lambda_{E,H}$. We also discuss the renormalization-group improvement for the sum rules and present update on the values of $\lambda_{E,H}$.
[ { "created": "Fri, 30 Sep 2011 10:33:32 GMT", "version": "v1" }, { "created": "Thu, 12 Dec 2013 23:02:29 GMT", "version": "v2" } ]
2013-12-16
[ [ "Nishikawa", "Tetsuo", "" ], [ "Tanaka", "Kazuhiro", "" ] ]
We discuss the QCD sum rule calculation of the heavy-quark effective theory parameters, $\lambda_E$ and $\lambda_H$, which correspond to matrix elements representing quark-gluon three-body components in the $B$-meson wavefunction. We derive the sum rules for $\lambda_{E,H}$ calculating the new higher-order QCD corrections, i.e., the order $\alpha_s$ radiative corrections to the Wilson coefficients associated with the dimension-5 quark-gluon mixed condensates, and the power corrections due to the dimension-6 vacuum condensates. We find that the new radiative corrections significantly improve the stability of the corresponding Borel sum rules and lead to the reduction of the values of $\lambda_{E,H}$. We also discuss the renormalization-group improvement for the sum rules and present update on the values of $\lambda_{E,H}$.
1210.4712
D. P. Roy
D. P. Roy
Determination of the Third Neutrino-Mixing Angle {\theta}_(13) and its Implications
27 pages, 6 figures,typos corrected, published in J. Phys. G as a topical review
J. Phys. G40, 053001 (2013)
10.1088/0954-3899/40/5/053001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Till 2010 we had three unknown parameters of neutrino oscillation: the third mixing angle {\theta}_(13), the sign of the larger mass difference {\Delta}m^(2)_(31) and the CP violating phase {\delta}. Thanks to a number of consistent experimental results since then, culminating in the recent Daya Bay reactor neutrino data, we have a definitive determination of {\theta}_(13) now. Moreover its measured value, sin^(2)_(2 {\theta}_(13)) = 0.1, is close to its earlier upper limit. This has promising implications for the determination of the two remaining unknown parameters from the present and proposed accelerator neutrino experiments in the foreseeable future. This article presents a pedagogical review of these profound developments for the wider community of young physicists including university students.
[ { "created": "Wed, 17 Oct 2012 12:21:09 GMT", "version": "v1" }, { "created": "Wed, 20 Mar 2013 12:27:17 GMT", "version": "v2" }, { "created": "Fri, 14 Jun 2013 10:36:13 GMT", "version": "v3" }, { "created": "Mon, 15 Jun 2015 08:15:31 GMT", "version": "v4" } ]
2015-06-16
[ [ "Roy", "D. P.", "" ] ]
Till 2010 we had three unknown parameters of neutrino oscillation: the third mixing angle {\theta}_(13), the sign of the larger mass difference {\Delta}m^(2)_(31) and the CP violating phase {\delta}. Thanks to a number of consistent experimental results since then, culminating in the recent Daya Bay reactor neutrino data, we have a definitive determination of {\theta}_(13) now. Moreover its measured value, sin^(2)_(2 {\theta}_(13)) = 0.1, is close to its earlier upper limit. This has promising implications for the determination of the two remaining unknown parameters from the present and proposed accelerator neutrino experiments in the foreseeable future. This article presents a pedagogical review of these profound developments for the wider community of young physicists including university students.
2302.13879
Luan Cheng
Huiqiang Ding, Luan Cheng, Tingting Dai, Enke Wang, Wei-Ning Zhang
The Spectrum of Low-$p_T$ $J/\psi$ in Heavy-Ion Collisions in a Statistical Two-Body Fractal Model
12 pages, 5 figures
null
10.3390/e25121655
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We establish a statistical two-body fractal (STF) model to study the spectrum of $J/\psi$. $J/\psi$ serves as a reliable probe in heavy-ion collisions. The distribution of $J/\psi$ in hadron gas is influenced by flow, quantum and strong interaction effects. Previous models have predominantly focused on one or two of these effects while neglecting the others, resulting in the inclusion of unconsidered effects in the fitted parameters. Here, we study the issue from a new point of view by analyzing the fact that all three effects induce a self-similarity structure, involving a $J/\psi$-$\pi$ two-meson state and a $J/\psi$, $\pi$ two-quark state, respectively. We introduce modification factor $q_{TBS}$ and $q_2$ into the probability and entropy of charmonium. $q_{TBS}$ denotes the modification of self-similarity on $J/\psi$, $q_2$ denotes that of self-similarity and strong interaction between \emph{c }and $\bar{c}$ on quarks. By solving the probability and entropy equations, we derive the values of $q_{TBS}$ and $q_2$ at various collision energies and centralities. Substituting the value of $q_{TBS}$ into distribution function, we successfully obtain the transverse momentum spectrum of low-$p_T$ $J/\psi$, which demonstrates good agreement with experimental data. The STF model can be employed to investigate other mesons and resonance states.
[ { "created": "Mon, 27 Feb 2023 15:27:05 GMT", "version": "v1" }, { "created": "Mon, 29 May 2023 13:09:26 GMT", "version": "v2" }, { "created": "Tue, 30 May 2023 14:42:21 GMT", "version": "v3" }, { "created": "Wed, 13 Dec 2023 23:29:02 GMT", "version": "v4" } ]
2023-12-15
[ [ "Ding", "Huiqiang", "" ], [ "Cheng", "Luan", "" ], [ "Dai", "Tingting", "" ], [ "Wang", "Enke", "" ], [ "Zhang", "Wei-Ning", "" ] ]
We establish a statistical two-body fractal (STF) model to study the spectrum of $J/\psi$. $J/\psi$ serves as a reliable probe in heavy-ion collisions. The distribution of $J/\psi$ in hadron gas is influenced by flow, quantum and strong interaction effects. Previous models have predominantly focused on one or two of these effects while neglecting the others, resulting in the inclusion of unconsidered effects in the fitted parameters. Here, we study the issue from a new point of view by analyzing the fact that all three effects induce a self-similarity structure, involving a $J/\psi$-$\pi$ two-meson state and a $J/\psi$, $\pi$ two-quark state, respectively. We introduce modification factor $q_{TBS}$ and $q_2$ into the probability and entropy of charmonium. $q_{TBS}$ denotes the modification of self-similarity on $J/\psi$, $q_2$ denotes that of self-similarity and strong interaction between \emph{c }and $\bar{c}$ on quarks. By solving the probability and entropy equations, we derive the values of $q_{TBS}$ and $q_2$ at various collision energies and centralities. Substituting the value of $q_{TBS}$ into distribution function, we successfully obtain the transverse momentum spectrum of low-$p_T$ $J/\psi$, which demonstrates good agreement with experimental data. The STF model can be employed to investigate other mesons and resonance states.
hep-ph/0005306
Young-Jae Kim
T. Han, Y.J. Kim, A. Likhoded and G. Valencia
Top-quark couplings to TeV resonances at future lepton colliders
33 pages, 9 ps figures, 1 table
Nucl.Phys. B593 (2001) 415-437
10.1016/S0550-3213(00)00643-X
MADPH-00-1181, FERMILAB-Pub-00/113-T
hep-ph
null
We study the processes $W_L W_L \to t \bar t$ and $W_L Z_L \to t\bar b (\bar t b)$ at future lepton colliders as probes of the couplings of the top quark to resonances at the TeV scale. We consider the cases in which the dominant low energy feature of a strongly interacting electroweak symmetry breaking sector is either a scalar or a vector resonance with mass near 1 TeV. We find that future lepton colliders with high energy and high luminosity have great potential to sensitively probe these physics scenarios. In particular, at a 1.5 TeV linear collider with an integrated luminosity of 200 fb$^{-1}$, we expect about 120 events for either a scalar or a vector to decay to $t\bar t, t \bar b$. Their leading partial decay widths, which characterize the coupling strengths, can be statistically determined to about 10% level.
[ { "created": "Tue, 30 May 2000 19:52:46 GMT", "version": "v1" } ]
2009-10-31
[ [ "Han", "T.", "" ], [ "Kim", "Y. J.", "" ], [ "Likhoded", "A.", "" ], [ "Valencia", "G.", "" ] ]
We study the processes $W_L W_L \to t \bar t$ and $W_L Z_L \to t\bar b (\bar t b)$ at future lepton colliders as probes of the couplings of the top quark to resonances at the TeV scale. We consider the cases in which the dominant low energy feature of a strongly interacting electroweak symmetry breaking sector is either a scalar or a vector resonance with mass near 1 TeV. We find that future lepton colliders with high energy and high luminosity have great potential to sensitively probe these physics scenarios. In particular, at a 1.5 TeV linear collider with an integrated luminosity of 200 fb$^{-1}$, we expect about 120 events for either a scalar or a vector to decay to $t\bar t, t \bar b$. Their leading partial decay widths, which characterize the coupling strengths, can be statistically determined to about 10% level.
2103.02848
Koji Ishiwata
Koji Ishiwata
Axion mass in antiferromagnetic insulators
19 pages, 8 figures, published version
Phys. Rev. D 104, 016004 (2021)
10.1103/PhysRevD.104.016004
KANAZAWA-21-02
hep-ph cond-mat.mes-hall cond-mat.str-el
http://creativecommons.org/licenses/by/4.0/
We calculate axion potential in antiferromagnetic insulators from path integral. It is derived from the effective potential for the order parameter of the antiferromagnetic phase in insulators. Static and dynamical axions are defined consistently from the potential. Consequently antiferromagnetic/paramagnetic and topological/normal orders are classified. The dynamical axion is predicted in all phases and its mass turns out to be various values up to eV scale.
[ { "created": "Thu, 4 Mar 2021 06:15:56 GMT", "version": "v1" }, { "created": "Fri, 9 Jul 2021 05:02:21 GMT", "version": "v2" } ]
2021-07-12
[ [ "Ishiwata", "Koji", "" ] ]
We calculate axion potential in antiferromagnetic insulators from path integral. It is derived from the effective potential for the order parameter of the antiferromagnetic phase in insulators. Static and dynamical axions are defined consistently from the potential. Consequently antiferromagnetic/paramagnetic and topological/normal orders are classified. The dynamical axion is predicted in all phases and its mass turns out to be various values up to eV scale.
hep-ph/0512326
Koichi Hamaguchi
Wilfried Buchmuller, Koichi Hamaguchi, Oleg Lebedev, Michael Ratz
Local Grand Unification
14 pages, 9 figures. Based on talks presented at the GUSTAVOFEST, Lisbon, July 2005, and at the workshop `Strings and the real world', Ohio, November 2005. v2: Technical problems of listing references fixed
null
null
DESY 05-260
hep-ph hep-th
null
In the standard model matter fields form complete representations of a grand unified group whereas Higgs fields belong to incomplete `split' multiplets. This remarkable fact is naturally explained by `local grand unification' in higher-dimensional extensions of the standard model. Here, the generations of matter fields are localized in regions of compact space which are endowed with a GUT gauge symmetry whereas the Higgs doublets are bulk fields. We realize local grand unification in the framework of orbifold compactifications of the heterotic string, and we present an example with SO(10) as a local GUT group, which leads to the supersymmetric standard model as an effective four-dimensional theory. We also discuss different orbifold GUT limits and the unification of gauge and Yukawa couplings.
[ { "created": "Sat, 24 Dec 2005 15:34:57 GMT", "version": "v1" }, { "created": "Tue, 17 Jan 2006 14:54:44 GMT", "version": "v2" } ]
2007-05-23
[ [ "Buchmuller", "Wilfried", "" ], [ "Hamaguchi", "Koichi", "" ], [ "Lebedev", "Oleg", "" ], [ "Ratz", "Michael", "" ] ]
In the standard model matter fields form complete representations of a grand unified group whereas Higgs fields belong to incomplete `split' multiplets. This remarkable fact is naturally explained by `local grand unification' in higher-dimensional extensions of the standard model. Here, the generations of matter fields are localized in regions of compact space which are endowed with a GUT gauge symmetry whereas the Higgs doublets are bulk fields. We realize local grand unification in the framework of orbifold compactifications of the heterotic string, and we present an example with SO(10) as a local GUT group, which leads to the supersymmetric standard model as an effective four-dimensional theory. We also discuss different orbifold GUT limits and the unification of gauge and Yukawa couplings.
hep-ph/0205144
Mark Dierckxsens
M. Dierckxsens
Final State Interactions in Hadronic WW Decay at LEP
6 pages, to appear in the proceedings of the XXXVIIth Rencontres de Moriond EW, 9-16th March 2002, Les Arcs, France
null
null
null
hep-ph
null
An overview is given of the study of final state interactions in hadronically decaying W pairs produced in e^+e^--collisions as it is performed by the four LEP experiments. Bose-Einstein correlations are investigated by comparing like- with unlike-signed pairs of pions and/or using the mixed event analysis technique. Colour reconnection is examined with a method that compares the particle flow distributions in inter-jet regions.
[ { "created": "Tue, 14 May 2002 16:34:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dierckxsens", "M.", "" ] ]
An overview is given of the study of final state interactions in hadronically decaying W pairs produced in e^+e^--collisions as it is performed by the four LEP experiments. Bose-Einstein correlations are investigated by comparing like- with unlike-signed pairs of pions and/or using the mixed event analysis technique. Colour reconnection is examined with a method that compares the particle flow distributions in inter-jet regions.
hep-ph/9702226
U. Meissner
S.R. Beane, V. Bernard, T.-S.H. Lee, Ulf-G. Mei{\ss}ner, U. van Kolck
Neutral pion photoproduction on deuterium in baryon chiral perturbation theory to order q^4
25 pp, LaTeX, 6 figures
Nucl.Phys. A618 (1997) 381-401
10.1016/S0375-9474(97)00133-4
DOE/ER/40427-30-N96, DUKE-TH-96-131, LPT 96-20 and KFA-IKP(TH)-1996-08
hep-ph nucl-th
null
Threshold neutral pion photoproduction on the deuteron is studied in the framework of baryon chiral perturbation theory beyond next-to--leading order in the chiral expansion. To fourth order in small momenta, the amplitude is finite and a sum of two- and three-body interactions with no undetermined parameters. With accurate theoretical and experimental input from the single nucleon sector for the proton amplitude, we investigate the sensitivity of the threshold cross section to the elementary $\gamma n \to \pi^0 n$ amplitude. A precise measurement of the threshold cross section for $\gamma d \to \pi^0 d$ is called for.
[ { "created": "Mon, 3 Feb 1997 15:18:00 GMT", "version": "v1" } ]
2009-10-30
[ [ "Beane", "S. R.", "" ], [ "Bernard", "V.", "" ], [ "Lee", "T. -S. H.", "" ], [ "Meißner", "Ulf-G.", "" ], [ "van Kolck", "U.", "" ] ]
Threshold neutral pion photoproduction on the deuteron is studied in the framework of baryon chiral perturbation theory beyond next-to--leading order in the chiral expansion. To fourth order in small momenta, the amplitude is finite and a sum of two- and three-body interactions with no undetermined parameters. With accurate theoretical and experimental input from the single nucleon sector for the proton amplitude, we investigate the sensitivity of the threshold cross section to the elementary $\gamma n \to \pi^0 n$ amplitude. A precise measurement of the threshold cross section for $\gamma d \to \pi^0 d$ is called for.
1907.05020
Kfir Blum
Nitsan Bar, Kfir Blum, Guido D'Amico
Is there a supernova bound on axions?
10 pages, 5 figure. Added discussion, match PRD version
Phys. Rev. D 101, 123025 (2020)
10.1103/PhysRevD.101.123025
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a critical assessment of the SN1987A supernova cooling bound on axions and other light particles. Core-collapse simulations used in the literature to substantiate the bound omitted from the calculation the envelope exterior to the proto-neutron star (PNS). As a result, the only source of neutrinos in these simulations was, by construction, a cooling PNS. We show that if the canonical delayed neutrino mechanism failed to explode SN1987A, and if the pre-collapse star was rotating, then an accretion disk would form that could explain the late-time ($t\gtrsim5$ sec) neutrino events. Such accretion disk would be a natural feature if SN1987A was a collapse-induced thermonuclear explosion. Axions do not cool the disk and do not affect its neutrino output, provided the disk is optically-thin to neutrinos, as it naturally is. These considerations cast doubt on the supernova cooling bound.
[ { "created": "Thu, 11 Jul 2019 06:55:57 GMT", "version": "v1" }, { "created": "Thu, 11 Jun 2020 21:51:57 GMT", "version": "v2" } ]
2020-07-01
[ [ "Bar", "Nitsan", "" ], [ "Blum", "Kfir", "" ], [ "D'Amico", "Guido", "" ] ]
We present a critical assessment of the SN1987A supernova cooling bound on axions and other light particles. Core-collapse simulations used in the literature to substantiate the bound omitted from the calculation the envelope exterior to the proto-neutron star (PNS). As a result, the only source of neutrinos in these simulations was, by construction, a cooling PNS. We show that if the canonical delayed neutrino mechanism failed to explode SN1987A, and if the pre-collapse star was rotating, then an accretion disk would form that could explain the late-time ($t\gtrsim5$ sec) neutrino events. Such accretion disk would be a natural feature if SN1987A was a collapse-induced thermonuclear explosion. Axions do not cool the disk and do not affect its neutrino output, provided the disk is optically-thin to neutrinos, as it naturally is. These considerations cast doubt on the supernova cooling bound.
hep-ph/0008177
Raymond R. Volkas
Nicole F. Bell and Raymond R. Volkas
Bottom-up model for maximal $\nu_{\mu} - \nu_{\tau}$ mixing
RevTeX, 14 pages. Expanded discussion of the intermediate range force mediated by the light gauge boson. To appear in Phys. Rev. D
Phys.Rev.D63:013006,2001
10.1103/PhysRevD.63.013006
null
hep-ph
null
We construct a model which provides maximal mixing between a pseudo-Dirac $\nu_{\mu}/\nu_{\tau}$ pair, based on a local $U(1)_{L_{\mu}-L_{\tau}}$ symmetry. Its strengths, weaknesses and phenomenological consequences are examined. The mass gap necessitated by the pseudo-Dirac structure is most naturally associated with the LSND anomaly. The solar neutrino problem then requires a light mirror or sterile neutrino. By paying a fine-tuning price to nullify the mass gap, one can also invoke $\nu_e \to \nu_{\mu,\tau}$ for the solar problem. The model predicts a new intermediate range force mediated by the light gauge boson of $U(1)_{L_{\mu}-L_{\tau}}$. Through the mixing of $\mu$, $\tau$ and $e$, this force couples to electrons and thus may be searched for in precision ``gravity'' experiments.
[ { "created": "Thu, 17 Aug 2000 06:38:07 GMT", "version": "v1" }, { "created": "Mon, 6 Nov 2000 00:18:06 GMT", "version": "v2" } ]
2011-02-07
[ [ "Bell", "Nicole F.", "" ], [ "Volkas", "Raymond R.", "" ] ]
We construct a model which provides maximal mixing between a pseudo-Dirac $\nu_{\mu}/\nu_{\tau}$ pair, based on a local $U(1)_{L_{\mu}-L_{\tau}}$ symmetry. Its strengths, weaknesses and phenomenological consequences are examined. The mass gap necessitated by the pseudo-Dirac structure is most naturally associated with the LSND anomaly. The solar neutrino problem then requires a light mirror or sterile neutrino. By paying a fine-tuning price to nullify the mass gap, one can also invoke $\nu_e \to \nu_{\mu,\tau}$ for the solar problem. The model predicts a new intermediate range force mediated by the light gauge boson of $U(1)_{L_{\mu}-L_{\tau}}$. Through the mixing of $\mu$, $\tau$ and $e$, this force couples to electrons and thus may be searched for in precision ``gravity'' experiments.
hep-ph/0207205
Kacper Zalewski
Kacer Zalewski
Unified description of a class of models for Bose-Einstein correlations in multiple particle production processes
18 pages Latex2e no figures. Dedicated to Stefan Pokorski on his 60th birthday
Acta Phys.Polon. B33 (2002) 2643-2658
null
TPJU 12/2002
hep-ph
null
Numerous models have been proposed to describe the Bose-Einstein correlations in multiple particle production processes. In the present paper we describe a generalization, which includes many previous models as special cases and, therefore, can be useful for work of comparison. We apply the powerful methods of eigenfunction expansions and generating functionals, which often make the calculations much shorter than in the original papers.
[ { "created": "Wed, 17 Jul 2002 12:48:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zalewski", "Kacer", "" ] ]
Numerous models have been proposed to describe the Bose-Einstein correlations in multiple particle production processes. In the present paper we describe a generalization, which includes many previous models as special cases and, therefore, can be useful for work of comparison. We apply the powerful methods of eigenfunction expansions and generating functionals, which often make the calculations much shorter than in the original papers.
1905.10372
Ivan Esteban
Ivan Esteban, Jacobo Lopez-Pavon, Ivan Martinez-Soler, Jordi Salvado
Looking at the axionic dark sector with ANITA
New figure added (Fig. 5): estimation of ALP mass, coupling and corrected value of burst density, consistent with ANITA and present ALP experimental bounds. Estimation of ALP burst rate reaching the Earth added. Matches version accepted by EPJC
null
10.1140/epjc/s10052-020-7816-y
FTUV-19-0523.2645, IFIC/19-14, FERMILAB-PUB-19-241-T, NUHEP-TH/19-06
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ANITA experiment has recently observed two anomalous events emerging from well below the horizon. Even though they are consistent with tau cascades, a high energy Standard Model or Beyond the Standard Model explanation is challenging and in tension with other experiments. We study under which conditions the reflection of generic radio pulses can reproduce these signals. We propose that these pulses can be resonantly produced in the ionosphere via axion-photon conversion. This naturally explains the direction and polarization of the events and avoids other experimental bounds.
[ { "created": "Fri, 24 May 2019 18:00:00 GMT", "version": "v1" }, { "created": "Sun, 30 Jun 2019 19:26:56 GMT", "version": "v2" }, { "created": "Fri, 6 Mar 2020 18:08:44 GMT", "version": "v3" } ]
2020-04-22
[ [ "Esteban", "Ivan", "" ], [ "Lopez-Pavon", "Jacobo", "" ], [ "Martinez-Soler", "Ivan", "" ], [ "Salvado", "Jordi", "" ] ]
The ANITA experiment has recently observed two anomalous events emerging from well below the horizon. Even though they are consistent with tau cascades, a high energy Standard Model or Beyond the Standard Model explanation is challenging and in tension with other experiments. We study under which conditions the reflection of generic radio pulses can reproduce these signals. We propose that these pulses can be resonantly produced in the ionosphere via axion-photon conversion. This naturally explains the direction and polarization of the events and avoids other experimental bounds.