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2201.04840
Luis Roca
L. R. Dai, E. Oset, A. Feijoo, R. Molina, L. Roca, A. Mart\'inez Torres, K. P. Khemchandani
Masses and widths of the exotic molecular $B_{(s)}^{(*)} B_{(s)}^{(*)}$ states
23 pages, 10 figures
null
10.1103/PhysRevD.105.074017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the interaction of the doubly bottom systems $BB$, $B^* B$, $B_s B$, $B_s^* B$, $B^* B^*$, $B^* B_s$, $B^*B_s^*$, $B_s B_s$, $B_s B_s^*$, $B_s^* B_s^*$ by means of vector meson exchange with Lagrangians from an extension of the local hidden gauge approach. The full s-wave scattering matrix is obtained implementing unitarity in coupled channels by means of the Bethe-Salpeter equation. We find poles below the channel thresholds for the attractively interacting channels $B^* B$ in $I=0$, $B^*_s B-B^*B_s$ in $I=\frac{1}{2}$, $B^* B^*$ in $I=0$, and $B^*_s B^*$ in $I=\frac{1}{2}$, all of them with $J^P=1^+$. For these cases the widths are evaluated identifyng the dominant source of imaginary part. We find binding energies of the order of $10-20$ MeV, and the widths vary much from one system to the other: of the order of 10-100 eV for the $B^* B$ system and $B^*_s B-B^*B_s$, about $6$ MeV for the $B^* B^*$ system and of the order of $0.5$ MeV for the $B^*_s B^*$ system.
[ { "created": "Thu, 13 Jan 2022 08:59:03 GMT", "version": "v1" } ]
2022-05-04
[ [ "Dai", "L. R.", "" ], [ "Oset", "E.", "" ], [ "Feijoo", "A.", "" ], [ "Molina", "R.", "" ], [ "Roca", "L.", "" ], [ "Torres", "A. Martínez", "" ], [ "Khemchandani", "K. P.", "" ] ]
We study the interaction of the doubly bottom systems $BB$, $B^* B$, $B_s B$, $B_s^* B$, $B^* B^*$, $B^* B_s$, $B^*B_s^*$, $B_s B_s$, $B_s B_s^*$, $B_s^* B_s^*$ by means of vector meson exchange with Lagrangians from an extension of the local hidden gauge approach. The full s-wave scattering matrix is obtained implementing unitarity in coupled channels by means of the Bethe-Salpeter equation. We find poles below the channel thresholds for the attractively interacting channels $B^* B$ in $I=0$, $B^*_s B-B^*B_s$ in $I=\frac{1}{2}$, $B^* B^*$ in $I=0$, and $B^*_s B^*$ in $I=\frac{1}{2}$, all of them with $J^P=1^+$. For these cases the widths are evaluated identifyng the dominant source of imaginary part. We find binding energies of the order of $10-20$ MeV, and the widths vary much from one system to the other: of the order of 10-100 eV for the $B^* B$ system and $B^*_s B-B^*B_s$, about $6$ MeV for the $B^* B^*$ system and of the order of $0.5$ MeV for the $B^*_s B^*$ system.
1402.7078
Johannes Henn
Johannes M. Henn, Kirill Melnikov, Vladimir A. Smirnov
Two-loop planar master integrals for the production of off-shell vector bosons in hadron collisions
28 pages, many figures; ancillary files included with arXiv submission
null
10.1007/s13130-014-8200-x
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the calculation of all planar master integrals that are needed for the computation of NNLO QCD corrections to the production of two off-shell vector bosons in hadron collisions. The most complicated representatives of integrals in this class are the two-loop four-point functions where two external lines are on the light-cone and two other external lines have different invariant masses. We compute these and other relevant integrals analytically using differential equations in external kinematic variables and express our results in terms of Goncharov polylogarithms. The case of two equal off-shellnesses, recently considered in Ref. [1], appears as a particular case of our general solution.
[ { "created": "Thu, 27 Feb 2014 21:00:22 GMT", "version": "v1" } ]
2015-06-18
[ [ "Henn", "Johannes M.", "" ], [ "Melnikov", "Kirill", "" ], [ "Smirnov", "Vladimir A.", "" ] ]
We describe the calculation of all planar master integrals that are needed for the computation of NNLO QCD corrections to the production of two off-shell vector bosons in hadron collisions. The most complicated representatives of integrals in this class are the two-loop four-point functions where two external lines are on the light-cone and two other external lines have different invariant masses. We compute these and other relevant integrals analytically using differential equations in external kinematic variables and express our results in terms of Goncharov polylogarithms. The case of two equal off-shellnesses, recently considered in Ref. [1], appears as a particular case of our general solution.
hep-ph/9408241
Mark Hindmarsh
Mark Hindmarsh
Sphalerons and Strings
(6pp, LaTeX + 3 eps figures, self-unpacking uuencoded. Needs epsf.sty.) SUSX-TH-94/71
null
null
null
hep-ph
null
This work is based on a paper with Margaret James, to appear in Phys Rev D. In it we showed that the dipole moment of the sphaleron has its origin in two components: a ring of electric current circulating around the edge of the sphaleron; and also two regions of opposite magnetic charge above and below the ring. This magnetic charge has a partly topological explanation, arising from the fact that the sphaleron is axisymmetric and parity invariant. Here, I discuss the definition of the electromagnetic field and its sources in the Standard Model, comparing the one we use with the better-known one of 't Hooft. I also discuss the resemblance between the sphaleron and Nambu's ``dumb-bell'' -- a segment of $Z$-string which connects a monopole to an antimonopole.
[ { "created": "Fri, 5 Aug 1994 13:59:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hindmarsh", "Mark", "" ] ]
This work is based on a paper with Margaret James, to appear in Phys Rev D. In it we showed that the dipole moment of the sphaleron has its origin in two components: a ring of electric current circulating around the edge of the sphaleron; and also two regions of opposite magnetic charge above and below the ring. This magnetic charge has a partly topological explanation, arising from the fact that the sphaleron is axisymmetric and parity invariant. Here, I discuss the definition of the electromagnetic field and its sources in the Standard Model, comparing the one we use with the better-known one of 't Hooft. I also discuss the resemblance between the sphaleron and Nambu's ``dumb-bell'' -- a segment of $Z$-string which connects a monopole to an antimonopole.
hep-ph/0308189
Vadim Guzey
L. Frankfurt (Tel Aviv U.), V. Guzey (TP2, Ruhr U.), M. Strikman (Penn State U.)
Leading twist coherent diffraction on nuclei in deep inelastic scattering at small x and nuclear shadowing
14 pages, 7 figures. Extended discussion. Final version published in PLB
Phys.Lett. B586 (2004) 41-52
10.1016/j.physletb.2004.02.019
RUB-TP2-11/03
hep-ph
null
We extend the theory of leading twist nuclear shadowing to calculate leading twist nuclear diffractive parton distribution functions (nDPDFs). We observe that the quark and gluon nPDFs have different patterns of the $A$-dependence. It is found that the probability of diffraction in the quark channel increases with $A$, reaching about 30% at $x \sim 10^{-4}$ for $A \sim 200$, and weakly decreases with $Q^2$. In the gluon channel, the probability of diffraction is large for all nuclei ($\sim 40$% for heavy nuclei at $x \sim 10^{-4}$ and $Q_0^2 \sim 4$ GeV$^2$), it weakly depends on $A$ and it decreases rather fast with increasing $Q^2$ -- the probability decreases by approximately a factor of two as $Q^2$ changes from 4 GeV$^2$ to 100 GeV$^2$. We also find that nuclear shadowing breaks down Regge factorization of nDPDFs, which is satisfied experimentally in the nucleon case. All these novel effects in nDPDFs are large enough to be straightforwardly measured in ultraperipheral collisions at the LHC.
[ { "created": "Tue, 19 Aug 2003 09:21:56 GMT", "version": "v1" }, { "created": "Mon, 12 Apr 2004 13:36:18 GMT", "version": "v2" } ]
2009-11-10
[ [ "Frankfurt", "L.", "", "Tel Aviv U." ], [ "Guzey", "V.", "", "TP2, Ruhr U." ], [ "Strikman", "M.", "", "Penn\n State U." ] ]
We extend the theory of leading twist nuclear shadowing to calculate leading twist nuclear diffractive parton distribution functions (nDPDFs). We observe that the quark and gluon nPDFs have different patterns of the $A$-dependence. It is found that the probability of diffraction in the quark channel increases with $A$, reaching about 30% at $x \sim 10^{-4}$ for $A \sim 200$, and weakly decreases with $Q^2$. In the gluon channel, the probability of diffraction is large for all nuclei ($\sim 40$% for heavy nuclei at $x \sim 10^{-4}$ and $Q_0^2 \sim 4$ GeV$^2$), it weakly depends on $A$ and it decreases rather fast with increasing $Q^2$ -- the probability decreases by approximately a factor of two as $Q^2$ changes from 4 GeV$^2$ to 100 GeV$^2$. We also find that nuclear shadowing breaks down Regge factorization of nDPDFs, which is satisfied experimentally in the nucleon case. All these novel effects in nDPDFs are large enough to be straightforwardly measured in ultraperipheral collisions at the LHC.
hep-ph/0007298
Tim Tait
Tim M.P. Tait, C.-P. Yuan
Single Top Production as a Window to Physics Beyond the Standard Model
References added and minor discussion improvements; results unchanged; Version to be published in PRD
Phys.Rev.D63:014018,2000
10.1103/PhysRevD.63.014018
ANL-HEP-PR-98-124 CERN-TH/2000-224
hep-ph
null
Production of single top quarks at a high energy hadron collider is studied as a means to identify physics beyond the standard model related to the electroweak symmetry breaking. The sensitivity of the $s$-channel $W^*$ mode, the $t$-channel $W$-gluon fusion mode, and the \tw mode to various possible forms of new physics is assessed, and it is found that the three modes are sensitive to different forms of new physics, indicating that they provide complimentary information about the properties of the top quark. Polarization observables are also considered, and found to provide potentially useful information about the structure of the interactions of top.
[ { "created": "Wed, 26 Jul 2000 15:52:46 GMT", "version": "v1" }, { "created": "Tue, 17 Oct 2000 21:46:00 GMT", "version": "v2" } ]
2010-11-24
[ [ "Tait", "Tim M. P.", "" ], [ "Yuan", "C. -P.", "" ] ]
Production of single top quarks at a high energy hadron collider is studied as a means to identify physics beyond the standard model related to the electroweak symmetry breaking. The sensitivity of the $s$-channel $W^*$ mode, the $t$-channel $W$-gluon fusion mode, and the \tw mode to various possible forms of new physics is assessed, and it is found that the three modes are sensitive to different forms of new physics, indicating that they provide complimentary information about the properties of the top quark. Polarization observables are also considered, and found to provide potentially useful information about the structure of the interactions of top.
0902.0628
Bohdan Grzadkowski
Bohdan Grzadkowski, Jose Wudka
Pragmatic approach to the little hierarchy problem: the case for Dark Matter and neutrino physics
discussion of multi singlet case added
Phys.Rev.Lett.103:091802,2009
10.1103/PhysRevLett.103.091802
IFT-09-01, UCRHEP-T463
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the addition of real scalars (gauge singlets) to the Standard Model can both ameliorate the little hierarchy problem and provide realistic Dark Matter candidates. To this end, the coupling of the new scalars to the standard Higgs boson must be relatively strong and their mass should be in the 1-3 TeV range, while the lowest cutoff of the (unspecified) UV completion must be >~ 5 TeV, depending on the Higgs boson mass and the number of singlets present. The existence of the singlets also leads to realistic and surprisingly reach neutrino physics. The resulting light neutrino mass spectrum and mixing angles are consistent with the constraints from the neutrino oscillations.
[ { "created": "Tue, 3 Feb 2009 21:52:30 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 2009 16:44:09 GMT", "version": "v2" }, { "created": "Thu, 20 Aug 2009 16:34:51 GMT", "version": "v3" } ]
2010-04-23
[ [ "Grzadkowski", "Bohdan", "" ], [ "Wudka", "Jose", "" ] ]
We show that the addition of real scalars (gauge singlets) to the Standard Model can both ameliorate the little hierarchy problem and provide realistic Dark Matter candidates. To this end, the coupling of the new scalars to the standard Higgs boson must be relatively strong and their mass should be in the 1-3 TeV range, while the lowest cutoff of the (unspecified) UV completion must be >~ 5 TeV, depending on the Higgs boson mass and the number of singlets present. The existence of the singlets also leads to realistic and surprisingly reach neutrino physics. The resulting light neutrino mass spectrum and mixing angles are consistent with the constraints from the neutrino oscillations.
2306.07865
Kristjan Kannike
Kristjan Kannike, Aleksei Kubarski, Luca Marzola and Antonio Racioppi
Pseudo-Goldstone dark matter in a radiative inverse seesaw scenario
31 pages, 3 figures, version published in JHEP, typos corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a scale-invariant inverse seesaw model with dynamical breaking of gauge symmetry and lepton number. In some regions of the parameter space, the Majoron - the pseudo-Goldstone of lepton number breaking - is a viable dark matter candidate. The bound on the Majoron decay rate implies a very large dilaton vacuum expectation value, which also results in a suppression of other dark matter couplings. Because of that, the observed dark matter relic abundance can only be matched via the freeze-in mechanism. The scalar field which gives mass to heavy neutrinos can play the role of the inflaton, resulting in a tensor-to-scalar ratio $r \lesssim 0.01$ for metric inflation and $r \lesssim 0.21$ for Palatini gravity.
[ { "created": "Tue, 13 Jun 2023 15:50:10 GMT", "version": "v1" }, { "created": "Mon, 11 Dec 2023 18:04:25 GMT", "version": "v2" }, { "created": "Mon, 8 Jan 2024 11:33:35 GMT", "version": "v3" } ]
2024-01-09
[ [ "Kannike", "Kristjan", "" ], [ "Kubarski", "Aleksei", "" ], [ "Marzola", "Luca", "" ], [ "Racioppi", "Antonio", "" ] ]
We consider a scale-invariant inverse seesaw model with dynamical breaking of gauge symmetry and lepton number. In some regions of the parameter space, the Majoron - the pseudo-Goldstone of lepton number breaking - is a viable dark matter candidate. The bound on the Majoron decay rate implies a very large dilaton vacuum expectation value, which also results in a suppression of other dark matter couplings. Because of that, the observed dark matter relic abundance can only be matched via the freeze-in mechanism. The scalar field which gives mass to heavy neutrinos can play the role of the inflaton, resulting in a tensor-to-scalar ratio $r \lesssim 0.01$ for metric inflation and $r \lesssim 0.21$ for Palatini gravity.
0705.2791
Shunzo Kumano
M. Hirai, S. Kumano, T.-H. Nagai, and K. Sudoh
Global analysis for determining fragmentation functions and their uncertainties in light hadrons
4 pages, LaTeX, 6 eps files, to be published in proceedings of 42nd Rencontres de Moriond on QCD and high energy hadronic interactions, La Thuile, Italy, 17-24 Mar 2007. A code for calculating the fragmentation functions and their uncertainties can be obtained from http://research.kek.jp/people/kumanos/ffs.html
null
null
KEK-TH-1146
hep-ph hep-ex nucl-ex nucl-th
null
Fragmentation functions are determined for the pion, kaon, and proton by analyzing charged-hadron production data in electron-positron annihilation. It is important that uncertainties of the determined fragmentation functions are estimated in this analysis. Analysis results indicate that gluon and light-quark functions have large uncertainties especially at small Q^2. We find that next-to-leading-order (NLO) uncertainties are significantly reduced in comparison with leading-order (LO) ones in the pion and kaon. The fragmentation functions are very different in various analysis groups. However, all the recent functions are roughly within the estimated uncertainties, which indicates that they are consistent with each other. We provide a code for calculating the fragmentation functions and their uncertainties at a given kinematical point of z and Q^2 by a user.
[ { "created": "Sat, 19 May 2007 01:12:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hirai", "M.", "" ], [ "Kumano", "S.", "" ], [ "Nagai", "T. -H.", "" ], [ "Sudoh", "K.", "" ] ]
Fragmentation functions are determined for the pion, kaon, and proton by analyzing charged-hadron production data in electron-positron annihilation. It is important that uncertainties of the determined fragmentation functions are estimated in this analysis. Analysis results indicate that gluon and light-quark functions have large uncertainties especially at small Q^2. We find that next-to-leading-order (NLO) uncertainties are significantly reduced in comparison with leading-order (LO) ones in the pion and kaon. The fragmentation functions are very different in various analysis groups. However, all the recent functions are roughly within the estimated uncertainties, which indicates that they are consistent with each other. We provide a code for calculating the fragmentation functions and their uncertainties at a given kinematical point of z and Q^2 by a user.
hep-ph/0201296
Stanley J. Brodsky
Stanley J. Brodsky, Dae Sung Hwang, and Ivan Schmidt
Final-State Interactions and Single-Spin Asymmetries in Semi-Inclusive Deep Inelastic Scattering
Version to appear in Physics Letters B. Typographical errors corrected in Eqs. (13) and (14)
Phys.Lett.B530:99-107,2002
10.1016/S0370-2693(02)01320-5
SLAC-PUB-9135, USM-TH-121
hep-ph
null
Recent measurements from the HERMES and SMC collaborations show a remarkably large azimuthal single-spin asymmetries A_{UL} and A_{UT} of the proton in semi-inclusive pion leptoproduction. We show that final-state interactions from gluon exchange between the outgoing quark and the target spectator system lead to single-spin asymmetries in deep inelastic lepton-proton scattering at leading twist in perturbative QCD; i.e., the rescattering corrections are not power-law suppressed at large photon virtuality Q^2 at fixed x_{bj}. The existence of such single-spin asymmetries requires a phase difference between two amplitudes coupling the proton target with J^z_p = + 1/2 and -1/2 to the same final state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. We show that the exchange of gauge particles between the outgoing quark and the proton spectators produces a Coulomb-like complex phase which depends on the angular momentum L_z of the proton's constituents and is thus distinct for different proton spin amplitudes. The single-spin asymmetry which arises from such final-state interactions does not factorize into a product of distribution function and fragmentation function, and it is not related to the transversity distribution delta q(x,Q) which correlates transversely polarized quarks with the spin of the transversely polarized target nucleon.
[ { "created": "Thu, 31 Jan 2002 00:58:08 GMT", "version": "v1" }, { "created": "Fri, 22 Feb 2002 23:13:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Brodsky", "Stanley J.", "" ], [ "Hwang", "Dae Sung", "" ], [ "Schmidt", "Ivan", "" ] ]
Recent measurements from the HERMES and SMC collaborations show a remarkably large azimuthal single-spin asymmetries A_{UL} and A_{UT} of the proton in semi-inclusive pion leptoproduction. We show that final-state interactions from gluon exchange between the outgoing quark and the target spectator system lead to single-spin asymmetries in deep inelastic lepton-proton scattering at leading twist in perturbative QCD; i.e., the rescattering corrections are not power-law suppressed at large photon virtuality Q^2 at fixed x_{bj}. The existence of such single-spin asymmetries requires a phase difference between two amplitudes coupling the proton target with J^z_p = + 1/2 and -1/2 to the same final state, the same amplitudes which are necessary to produce a nonzero proton anomalous magnetic moment. We show that the exchange of gauge particles between the outgoing quark and the proton spectators produces a Coulomb-like complex phase which depends on the angular momentum L_z of the proton's constituents and is thus distinct for different proton spin amplitudes. The single-spin asymmetry which arises from such final-state interactions does not factorize into a product of distribution function and fragmentation function, and it is not related to the transversity distribution delta q(x,Q) which correlates transversely polarized quarks with the spin of the transversely polarized target nucleon.
hep-ph/9408254
Per Elmfors
Per Elmfors, Randy Kobes
The Thermal Beta-Function in Yang-Mills Theory
16pp,latex + epsf.sty, Nordita-94/36 P
Phys. Rev. D 51, 774 (1995)
10.1103/PhysRevD.51.774
null
hep-ph hep-th
null
Previous calculations of the thermal beta-function in a hot Yang--Mills gas at the one--loop level have exposed problems with the gauge dependence and with the sign, which is opposite to what one would expect for asymptotic freedom. We show that inclusion of higher--loop effects through a static Braaten--Pisarski resummation is necessary to consistently obtain the leading term, but alters the results only quantitatively. The sign, in particular, remains the same. We also explore, by a crude parameterization, the effects a (non--perturbative) magnetic mass may have on these results.
[ { "created": "Tue, 9 Aug 1994 09:01:46 GMT", "version": "v1" } ]
2016-08-24
[ [ "Elmfors", "Per", "" ], [ "Kobes", "Randy", "" ] ]
Previous calculations of the thermal beta-function in a hot Yang--Mills gas at the one--loop level have exposed problems with the gauge dependence and with the sign, which is opposite to what one would expect for asymptotic freedom. We show that inclusion of higher--loop effects through a static Braaten--Pisarski resummation is necessary to consistently obtain the leading term, but alters the results only quantitatively. The sign, in particular, remains the same. We also explore, by a crude parameterization, the effects a (non--perturbative) magnetic mass may have on these results.
2306.15460
Jo\~ao Pedro Pino Gon\c{c}alves
Jo\~ao Gon\c{c}alves and Ant\'onio P. Morais and Ant\'onio Onofre and Roman Pasechnik
Exploring mixed lepton-quark interactions in non-resonant leptoquark production at the LHC
v1: 26 pages; 8 figures; 4 tables; v2: Additional discussion and references
null
null
CERN-TH-2023-072
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Searches for new physics (NP) at particle colliders typically involve multivariate analysis of kinematic distributions of final state particles produced in a decay of a hypothetical NP resonance. Since the pair-production cross-sections mediated by such resonances are strongly suppressed by the NP scale, this analysis becomes less relevant for NP searches for masses of the BSM resonance above 1 TeV. On the other hand, $t$-channel processes are less sensitive to the mass of the virtual mediator and therefore larger phase-space can be potentially probed as well as the couplings between the NP particles and the Standard Model fields. The fact that transitions between different generations of quarks and leptons may exist, the potential of the search presented in this article can be used, as a reference guide, to enlarge significantly the scope of searches performed at the LHC to flavour off-diagonal channels, in a theoretically consistent approach. In this work, we study non-resonant production of scalar leptoquarks which have been proposed in the literature to provide a potential avenue for radiative generation of neutrino masses, accommodating as well the existing flavour physics data. Final states involving just two muons at the LHC ($\mu^+, \mu^-$), are used as a well-motivated case study.
[ { "created": "Tue, 27 Jun 2023 13:25:15 GMT", "version": "v1" }, { "created": "Tue, 29 Aug 2023 20:04:19 GMT", "version": "v2" } ]
2023-08-31
[ [ "Gonçalves", "João", "" ], [ "Morais", "António P.", "" ], [ "Onofre", "António", "" ], [ "Pasechnik", "Roman", "" ] ]
Searches for new physics (NP) at particle colliders typically involve multivariate analysis of kinematic distributions of final state particles produced in a decay of a hypothetical NP resonance. Since the pair-production cross-sections mediated by such resonances are strongly suppressed by the NP scale, this analysis becomes less relevant for NP searches for masses of the BSM resonance above 1 TeV. On the other hand, $t$-channel processes are less sensitive to the mass of the virtual mediator and therefore larger phase-space can be potentially probed as well as the couplings between the NP particles and the Standard Model fields. The fact that transitions between different generations of quarks and leptons may exist, the potential of the search presented in this article can be used, as a reference guide, to enlarge significantly the scope of searches performed at the LHC to flavour off-diagonal channels, in a theoretically consistent approach. In this work, we study non-resonant production of scalar leptoquarks which have been proposed in the literature to provide a potential avenue for radiative generation of neutrino masses, accommodating as well the existing flavour physics data. Final states involving just two muons at the LHC ($\mu^+, \mu^-$), are used as a well-motivated case study.
hep-ph/9501250
Axel de la Macorra P.
Axel de la Macorra
Vanishing of the Cosmological Constant, Stability of the Dilaton and Inflation
9 pages, LaTeX, 3 figures compressed and uuencoded
Int.J.Mod.Phys. D5 (1996) 567
null
IFUNAM-FT-94-64
hep-ph astro-ph hep-th
null
We study the possibility of canceling the cosmological constant in supergravity string models. We show that with a suitable choice of superpotential the vacuum energy may vanish with the dilaton field at its minimum and supersymmetry broken with a large hierarchy. We derive the condition for which the introduction of a chiral potential, e.g. the inflaton potential, does not destabilize the dilaton field even in the region where the scalar potential takes positive values. This allows for an inflationary potential with the dilaton frozen at its minimum.
[ { "created": "Tue, 10 Jan 1995 01:49:51 GMT", "version": "v1" } ]
2016-09-01
[ [ "de la Macorra", "Axel", "" ] ]
We study the possibility of canceling the cosmological constant in supergravity string models. We show that with a suitable choice of superpotential the vacuum energy may vanish with the dilaton field at its minimum and supersymmetry broken with a large hierarchy. We derive the condition for which the introduction of a chiral potential, e.g. the inflaton potential, does not destabilize the dilaton field even in the region where the scalar potential takes positive values. This allows for an inflationary potential with the dilaton frozen at its minimum.
1710.09683
C\'edric Weiland
Julien Baglio and Cedric Weiland
Impact of heavy sterile neutrinos on the triple Higgs coupling
6+1 pages, 3 figures, proceedings of EPS-HEP 2017, the European Physical Society conference on High Energy Physics, 5-12 July 2017, Venice, Italy
null
null
IPPP/17/77
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New physics beyond the Standard Model is required to give mass to the light neutrinos. One of the simplest ideas is to introduce new heavy, gauge singlet fermions that play the role of right-handed neutrinos in a seesaw mechanism. They could have large Yukawa couplings to the Higgs boson, affecting the Higgs couplings and in particular the triple Higgs coupling $\lambda_{HHH}^{}$, the measure of which is one of the major goals of the LHC and of future colliders. We present a study of the impact of these heavy neutrinos on $\lambda_{HHH}^{}$ at the one-loop level, first in a simplified 3+1 model with one heavy Dirac neutrino and then in the inverse seesaw model. Taking into account all possible experimental constraints, we find that sizeable deviations of the order of 35% are possible, large enough to be detected at future colliders, making the triple Higgs coupling a new, viable observable to constrain neutrino mass models. The effects are generic and are expected in any new physics model including TeV-scale fermions with large Yukawa couplings to the Higgs boson, such as those using the neutrino portal.
[ { "created": "Thu, 26 Oct 2017 13:24:54 GMT", "version": "v1" } ]
2017-10-27
[ [ "Baglio", "Julien", "" ], [ "Weiland", "Cedric", "" ] ]
New physics beyond the Standard Model is required to give mass to the light neutrinos. One of the simplest ideas is to introduce new heavy, gauge singlet fermions that play the role of right-handed neutrinos in a seesaw mechanism. They could have large Yukawa couplings to the Higgs boson, affecting the Higgs couplings and in particular the triple Higgs coupling $\lambda_{HHH}^{}$, the measure of which is one of the major goals of the LHC and of future colliders. We present a study of the impact of these heavy neutrinos on $\lambda_{HHH}^{}$ at the one-loop level, first in a simplified 3+1 model with one heavy Dirac neutrino and then in the inverse seesaw model. Taking into account all possible experimental constraints, we find that sizeable deviations of the order of 35% are possible, large enough to be detected at future colliders, making the triple Higgs coupling a new, viable observable to constrain neutrino mass models. The effects are generic and are expected in any new physics model including TeV-scale fermions with large Yukawa couplings to the Higgs boson, such as those using the neutrino portal.
hep-ph/9907230
Uma Mahanta
Uma Mahanta
Violation of supersymmetric equivalence in R parity violating couplings
Plain Tex, 7 pages, no figures
Phys.Rev. D61 (2000) 015012
10.1103/PhysRevD.61.015012
MRI-PHY/P990718
hep-ph
null
In this paper we consider the violation of supersymmetric equvalence among the R parity violating couplings $lamabda_{ijk}$ caused by widely split chiral supermultiplets. We find that if $\lambda^{\prime}_{2jk}=g$ and $\lambda^{\prime}_{1jk}=e$ then the violation of SUSY equivalence is of the order of $5-6%$ in heavy SQCD models. On the other hand if $\lambda^{\prime}_{3jk}=g$ and $\lambda_{ijk}=e$ then the violation of SUSY equivalence can be as large as 9.4% in 2-1 models.
[ { "created": "Mon, 5 Jul 1999 12:41:23 GMT", "version": "v1" } ]
2009-10-31
[ [ "Mahanta", "Uma", "" ] ]
In this paper we consider the violation of supersymmetric equvalence among the R parity violating couplings $lamabda_{ijk}$ caused by widely split chiral supermultiplets. We find that if $\lambda^{\prime}_{2jk}=g$ and $\lambda^{\prime}_{1jk}=e$ then the violation of SUSY equivalence is of the order of $5-6%$ in heavy SQCD models. On the other hand if $\lambda^{\prime}_{3jk}=g$ and $\lambda_{ijk}=e$ then the violation of SUSY equivalence can be as large as 9.4% in 2-1 models.
2112.14275
Nikolaos Syrrakos
Dhimiter D. Canko and Nikolaos Syrrakos
Planar three-loop master integrals for $2 \to 2$ processes with one external massive particle
v2: added appendix on adjacency conditions, added ancillary files, version accepted for publication in JHEP; v1: 17 pages, 1 figure
null
10.1007/JHEP04(2022)134
TUM-HEP-1385/21
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present analytic results for the two tennis-court integral families relevant to $2\to2$ scattering processes involving one massive external particle and massless propagators in terms of Goncharov polylogarithms of up to transcendental weight six. We also present analytic results for physical kinematics for the ladder-box family and the two tennis-court families in terms of real-valued polylogarithmic functions, making our solutions well-suited for phenomenological applications.
[ { "created": "Tue, 28 Dec 2021 19:19:40 GMT", "version": "v1" }, { "created": "Tue, 29 Mar 2022 20:29:39 GMT", "version": "v2" } ]
2022-05-11
[ [ "Canko", "Dhimiter D.", "" ], [ "Syrrakos", "Nikolaos", "" ] ]
We present analytic results for the two tennis-court integral families relevant to $2\to2$ scattering processes involving one massive external particle and massless propagators in terms of Goncharov polylogarithms of up to transcendental weight six. We also present analytic results for physical kinematics for the ladder-box family and the two tennis-court families in terms of real-valued polylogarithmic functions, making our solutions well-suited for phenomenological applications.
1708.08350
Nikolaos Mavromatos
Nick E. Mavromatos (King's College London)
Matter-Antimatter Asymmetry in the Universe via String-Inspired CPT Violation at Early Eras
6 pages Latex, one figure, uses special macros; Invited talk at the International Workshop on CPT and Lorentz Symmetry in Field Theory, University of the Algarve, Faro (Portugal), July 6-7 2017. To appear in the Proceedings (Journal of Phys. Conf. Series (IOP))
null
10.1088/1742-6596/952/1/012006
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In four-space-time dimensional string/brane theory, obtained either through compactification of the extra spatial dimensions, or by appropriate restriction to brane worlds with three large spatial dimensions, the rich physics potential associated with the presence of non-trivial Kalb-Ramond (KR) axion-like fields has not been fully exploited so far. In this talk, I discuss a scenario whereby such fields produce spontaneous Lorentz- and CPT-violating cosmological backgrounds over which strings propagate, which in the early Universe can lead to Baryogenesis through Leptogenesis in models with heavy right-handed neutrinos.
[ { "created": "Mon, 28 Aug 2017 14:44:06 GMT", "version": "v1" } ]
2018-03-14
[ [ "Mavromatos", "Nick E.", "", "King's College London" ] ]
In four-space-time dimensional string/brane theory, obtained either through compactification of the extra spatial dimensions, or by appropriate restriction to brane worlds with three large spatial dimensions, the rich physics potential associated with the presence of non-trivial Kalb-Ramond (KR) axion-like fields has not been fully exploited so far. In this talk, I discuss a scenario whereby such fields produce spontaneous Lorentz- and CPT-violating cosmological backgrounds over which strings propagate, which in the early Universe can lead to Baryogenesis through Leptogenesis in models with heavy right-handed neutrinos.
hep-ph/9602368
Shoichi Sasaki Rcnp
Hideo Suganuma(RCNP), Sei Umisedo(RCNP), Shoich Sasaki(RCNP), Hiroshi Toki(RCNP), Osamu Miyamura(Hiroshima Univ.)
Monopole Dominance for Nonperturbative QCD
Talk presented by H. Suganuma at the Joint Japan-Australia Workshop on "Quarks, Hadrons and Nuclei'', 15 - 24 Nov. 1995, in Adelaide, Australia, 10 pages, Plain Latex, ( 6 figures - available on request from ssasaki@rcnp.osaka-u.ac.jp )
Austral.J.Phys.50:233-243,1997
10.1071/P96045
null
hep-ph
null
Monopole dominance for the nonperturbative features in QCD is studied both in the continuum and the lattice gauge theories. First, we study the dynamical chiral-symmetry breaking (D$\chi $SB) in the dual Higgs theory using the effective potential formalism. We find that the main driving force for D$\chi $SB is brought from the confinement part in the nonperturbative gluon propagator rather than the short-range part, which means monopole dominance for D$\chi $SB. Second, the correlation between instantons and QCD-monopoles is studied. In the Polyakov-like gauge, where $A_4(x)$ is diagonalized, the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Finally, using the SU(2) lattice gauge theory with $16^4$ and $16^3 \times 4$, the instanton number is measured in the singular (monopole-dominating) and regular (photon-dominating) sectors, respectively. Instantons and anti-instantons only exist in the monopole sector both in the maximally abelian gauge and in the Polyakov gauge, which means monopole dominance for the topological charge.
[ { "created": "Thu, 22 Feb 1996 13:17:06 GMT", "version": "v1" } ]
2019-08-15
[ [ "Suganuma", "Hideo", "", "RCNP" ], [ "Umisedo", "Sei", "", "RCNP" ], [ "Sasaki", "Shoich", "", "RCNP" ], [ "Toki", "Hiroshi", "", "RCNP" ], [ "Miyamura", "Osamu", "", "Hiroshima Univ." ] ]
Monopole dominance for the nonperturbative features in QCD is studied both in the continuum and the lattice gauge theories. First, we study the dynamical chiral-symmetry breaking (D$\chi $SB) in the dual Higgs theory using the effective potential formalism. We find that the main driving force for D$\chi $SB is brought from the confinement part in the nonperturbative gluon propagator rather than the short-range part, which means monopole dominance for D$\chi $SB. Second, the correlation between instantons and QCD-monopoles is studied. In the Polyakov-like gauge, where $A_4(x)$ is diagonalized, the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Finally, using the SU(2) lattice gauge theory with $16^4$ and $16^3 \times 4$, the instanton number is measured in the singular (monopole-dominating) and regular (photon-dominating) sectors, respectively. Instantons and anti-instantons only exist in the monopole sector both in the maximally abelian gauge and in the Polyakov gauge, which means monopole dominance for the topological charge.
0809.3743
Francesco Murgia
M. Anselmino (1), M. Boglione (1), U. D'Alesio (2,3), E. Leader (4), S. Melis (1), F. Murgia (3) ((1) University and INFN, Torino, Italy, (2) University of Cagliari (Italy), (3) INFN, Cagliari, Italy, (4) Imperial College, London, U.K.)
Sivers and Collins effects in polarized pp scattering processes
8 pages, 10 eps figures, uses ws-procs9x6.cls; Talk presented by F. Murgia at the II International Workshop on Transverse Polarisation Phenomena in Hard Processes (Transversity 2008), May 28-31, 2008, Ferrara (Italy)
null
10.1142/9789814277785_0015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize the present phenomenology of Sivers and Collins effects for transverse single spin asymmetries in polarized proton-proton collisions within the framework of the generalized parton model (GPM). We will discuss a reassessment of the Collins effect and some preliminary predictions for SSA's in p(pol) p -> pi,K + X processes at RHIC obtained using updated information from SIDIS data and a new set of meson fragmentation functions.
[ { "created": "Mon, 22 Sep 2008 16:43:34 GMT", "version": "v1" } ]
2017-08-23
[ [ "Anselmino", "M.", "" ], [ "Boglione", "M.", "" ], [ "D'Alesio", "U.", "" ], [ "Leader", "E.", "" ], [ "Melis", "S.", "" ], [ "Murgia", "F.", "" ] ]
We summarize the present phenomenology of Sivers and Collins effects for transverse single spin asymmetries in polarized proton-proton collisions within the framework of the generalized parton model (GPM). We will discuss a reassessment of the Collins effect and some preliminary predictions for SSA's in p(pol) p -> pi,K + X processes at RHIC obtained using updated information from SIDIS data and a new set of meson fragmentation functions.
2003.04057
Leonid Slad
L.M.Slad
Consequences of the MSW mechanism with Super-Kamiokande oscillation parameters and of the volume distribution of neutrino sources in the Sun
8 pages, v2: Additions: Erroneous assertions at the base of the MSW mechanism
EPL 135 (2021) 61002
10.1209/0295-5075/ac32f4
null
hep-ph astro-ph.SR hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The knowledge of the parameters of the solar neutrino oscillation model, provided by the SNO and Super-Kamiokande collaborations, enables us to obtain, with the Wolfenstein equation, a simple and clear analytical and numerical picture of the transformation of the neutrino state during its travel inside the Sun. We show that the resulting picture is not implicated in the characteristics of the neutrino state at the surface of the Sun and at the surface of the Earth. This circumstance with taking into account the volume distribution of solar neutrino sources indicates an obvious contradiction between the consequences of the MSW mechanism with parameters from SNO and Super-Kamiokande and the results of three of the five observed processes with solar neutrinos. Erroneous assertions at the base of the MSW mechanism are noted.
[ { "created": "Mon, 9 Mar 2020 12:14:51 GMT", "version": "v1" }, { "created": "Fri, 24 Sep 2021 14:09:49 GMT", "version": "v2" } ]
2021-12-14
[ [ "Slad", "L. M.", "" ] ]
The knowledge of the parameters of the solar neutrino oscillation model, provided by the SNO and Super-Kamiokande collaborations, enables us to obtain, with the Wolfenstein equation, a simple and clear analytical and numerical picture of the transformation of the neutrino state during its travel inside the Sun. We show that the resulting picture is not implicated in the characteristics of the neutrino state at the surface of the Sun and at the surface of the Earth. This circumstance with taking into account the volume distribution of solar neutrino sources indicates an obvious contradiction between the consequences of the MSW mechanism with parameters from SNO and Super-Kamiokande and the results of three of the five observed processes with solar neutrinos. Erroneous assertions at the base of the MSW mechanism are noted.
1203.5012
Anders Tranberg
Anders Tranberg and Bin Wu
Cold Electroweak Baryogenesis in the Two Higgs-Doublet Model
20 pages, 18 figures
null
10.1007/JHEP07(2012)087
BI-TP 2012/11
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the first investigation of cold electroweak baryogenesis in the two Higgs-doublet model (2HDM). The electroweak symmetry breaking transition is assumed to occur through a spinodal instability from a super-cooled initial state. We consider the creation of net Chern-Simons number, which through the axial anomaly is equivalent to baryon number. CP-violation is explicit in the scalar potential, but only in combination with P-violation is it possible for an asymmetry to be generated. This is introduced through the leading C- and P-breaking, but CP-invariant, term expected to arise upon integrating out the fermions in the theory. We perform real-time lattice simulations of the transition, and find the coefficient of this term required for successful bayogenesis.
[ { "created": "Thu, 22 Mar 2012 15:06:20 GMT", "version": "v1" } ]
2015-06-04
[ [ "Tranberg", "Anders", "" ], [ "Wu", "Bin", "" ] ]
We perform the first investigation of cold electroweak baryogenesis in the two Higgs-doublet model (2HDM). The electroweak symmetry breaking transition is assumed to occur through a spinodal instability from a super-cooled initial state. We consider the creation of net Chern-Simons number, which through the axial anomaly is equivalent to baryon number. CP-violation is explicit in the scalar potential, but only in combination with P-violation is it possible for an asymmetry to be generated. This is introduced through the leading C- and P-breaking, but CP-invariant, term expected to arise upon integrating out the fermions in the theory. We perform real-time lattice simulations of the transition, and find the coefficient of this term required for successful bayogenesis.
1701.00725
Mario Prausa
Mario Prausa
epsilon: A tool to find a canonical basis of master integrals
34 pages; changed reference to fuchsia
Comp.Phys.Commun. 219 (2017) 361-376
10.1016/j.cpc.2017.05.026
TTK-17-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In 2013, Henn proposed a special basis for a certain class of master integrals, which are expressible in terms of iterated integrals. In this basis, the master integrals obey a differential equation, where the right hand side is proportional to $\epsilon$ in $d=4-2\epsilon$ space-time dimensions. An algorithmic approach to find such a basis was found by Lee. We present the tool epsilon, an efficient implementation of Lee's algorithm based on the Fermat computer algebra system as computational backend.
[ { "created": "Tue, 3 Jan 2017 15:36:18 GMT", "version": "v1" }, { "created": "Tue, 20 Jun 2017 18:44:53 GMT", "version": "v2" }, { "created": "Wed, 28 Jun 2017 09:53:30 GMT", "version": "v3" } ]
2017-07-26
[ [ "Prausa", "Mario", "" ] ]
In 2013, Henn proposed a special basis for a certain class of master integrals, which are expressible in terms of iterated integrals. In this basis, the master integrals obey a differential equation, where the right hand side is proportional to $\epsilon$ in $d=4-2\epsilon$ space-time dimensions. An algorithmic approach to find such a basis was found by Lee. We present the tool epsilon, an efficient implementation of Lee's algorithm based on the Fermat computer algebra system as computational backend.
2007.01501
Seyed Peyman Zakeri
Zahra Rezaei, S. Peyman Zakeri
Singlet scalar dark matter in the non-commutative space-time: a viable hypothesis to explain the gamma-ray excess in the galactic center
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the non-commutative space-time to revive the idea that gamma-ray excess in the galactic center can be the result of particle dark matter annihilation. In the non-commutative theory, the photon spectrum is produced by direct emission during this annihilation where a photon can be embed in the final state together with other direct products in new vertices. In the various configurations of dark matter phenomenology, we adopt the most common model known as singlet scalar. Calculating the relevant aspects of the model, we can obtain the photon flux in the galactic center. Comparing our numerical achievements with experimental data reveals that non-commutative space-time can be a reliable framework to explain the gamma-ray excess.
[ { "created": "Fri, 3 Jul 2020 05:22:44 GMT", "version": "v1" } ]
2020-07-06
[ [ "Rezaei", "Zahra", "" ], [ "Zakeri", "S. Peyman", "" ] ]
We explore the non-commutative space-time to revive the idea that gamma-ray excess in the galactic center can be the result of particle dark matter annihilation. In the non-commutative theory, the photon spectrum is produced by direct emission during this annihilation where a photon can be embed in the final state together with other direct products in new vertices. In the various configurations of dark matter phenomenology, we adopt the most common model known as singlet scalar. Calculating the relevant aspects of the model, we can obtain the photon flux in the galactic center. Comparing our numerical achievements with experimental data reveals that non-commutative space-time can be a reliable framework to explain the gamma-ray excess.
1012.1022
Jean-Marc Richard
Jean-Marc Richard
Non-Abelian dynamics and heavy multiquarks, Steiner-tree confinement in hadron spectroscopy
8 pages, 5 figures, Invited talk at the 21st European Conference on Few-Body Problems in Physics, Salamanca, Spain, August 29th--September 3rd, 2010, to appear in the Proceedings, ed.~A.~Valcarce et al., to appear in Few-Body System
null
10.1007/s00601-010-0195-4
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A brief review is first presented of attempts to predict stable multiquark states within current models of hadron spectroscopy. Then a model combining flip-flop and connected Steiner trees is introduced and shown to lead to stable multiquarks, in particular for some configurations involving several heavy quarks and bearing exotic quantum numbers.
[ { "created": "Sun, 5 Dec 2010 18:14:35 GMT", "version": "v1" } ]
2015-05-20
[ [ "Richard", "Jean-Marc", "" ] ]
A brief review is first presented of attempts to predict stable multiquark states within current models of hadron spectroscopy. Then a model combining flip-flop and connected Steiner trees is introduced and shown to lead to stable multiquarks, in particular for some configurations involving several heavy quarks and bearing exotic quantum numbers.
1304.3776
Sadataka Furui
Sadataka Furui
Axial anomaly and the triality symmetry of leptons and hadrons
24 pages, 24 figures, References and comments added, to be published in Few-Body Systems(Springer)
null
10.1007/s00601-014-0897-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply the supersymmetric model of \'E. Cartan to the pseudoscalar meson decay into two photons, $\pi_0\to\gamma\gamma$, $\eta\to\gamma\gamma$ and $\eta'\to\gamma\gamma$. In the book of \'E. Cartan published in 1966, Dirac spinors ${^t(}A,B)$ and ${^t(}C,D)$ and vector fields $E$ and $E'$ were introduced and five supersymmetric transformations $G_{23}, G_{12}, G_{13}, G_{123}$ and $G_{132}$ were considered. The Pauli spinor is treated as a quaternion and the Dirac spinor is treated as an octonion. In the pseudoscalar meson decay, when the two final vector fields belong to the same group ($EE$ or $E'E'$), we call the diagram rescattering diagram. When they belong to different groups ($EE'$), the diagram is called twisted diagram. Assuming the triality selection rules of octonions, dark matter is interpreted as matter emitting photons in a different triality sector than that of electromagnetic probes in our world.
[ { "created": "Sat, 13 Apr 2013 04:42:15 GMT", "version": "v1" }, { "created": "Sat, 4 May 2013 02:07:45 GMT", "version": "v2" }, { "created": "Mon, 30 Dec 2013 08:55:31 GMT", "version": "v3" }, { "created": "Wed, 25 Jun 2014 14:41:21 GMT", "version": "v4" } ]
2015-06-15
[ [ "Furui", "Sadataka", "" ] ]
We apply the supersymmetric model of \'E. Cartan to the pseudoscalar meson decay into two photons, $\pi_0\to\gamma\gamma$, $\eta\to\gamma\gamma$ and $\eta'\to\gamma\gamma$. In the book of \'E. Cartan published in 1966, Dirac spinors ${^t(}A,B)$ and ${^t(}C,D)$ and vector fields $E$ and $E'$ were introduced and five supersymmetric transformations $G_{23}, G_{12}, G_{13}, G_{123}$ and $G_{132}$ were considered. The Pauli spinor is treated as a quaternion and the Dirac spinor is treated as an octonion. In the pseudoscalar meson decay, when the two final vector fields belong to the same group ($EE$ or $E'E'$), we call the diagram rescattering diagram. When they belong to different groups ($EE'$), the diagram is called twisted diagram. Assuming the triality selection rules of octonions, dark matter is interpreted as matter emitting photons in a different triality sector than that of electromagnetic probes in our world.
1110.5718
W-Y. P. Hwang
W-Y. Pauchy Hwang
The dark-matter world: Are there dark-matter galaxies?
arXiv admin note: substantial text overlap with arXiv:1107.0156 and arXiv:1009.1954
null
10.1142/S2010194512005703
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We attempt to answer whether neutrinos and antineutrinos, such as those in the cosmic neutrino background, would clusterize among themselves or even with other dark-matter particles, under certain time span, say 1 Gyr. With neutrino masses in place, the similarity with the ordinary matter increases and so is our confidence for neutrino clustering if time is long enough. In particular, the clusterings could happen with some seeds (cf. see the text for definition), the chance in the dark-matter world to form dark-matter galaxies increases. If the dark-matter galaxies would exist in a time span of 1 Gyr, then they might even dictate the formation of the ordinary galaxies (i.e. the dark-matter galaxies get formed first); thus, the implications for the structure of our Universe would be tremendous.
[ { "created": "Wed, 26 Oct 2011 07:18:45 GMT", "version": "v1" } ]
2015-05-30
[ [ "Hwang", "W-Y. Pauchy", "" ] ]
We attempt to answer whether neutrinos and antineutrinos, such as those in the cosmic neutrino background, would clusterize among themselves or even with other dark-matter particles, under certain time span, say 1 Gyr. With neutrino masses in place, the similarity with the ordinary matter increases and so is our confidence for neutrino clustering if time is long enough. In particular, the clusterings could happen with some seeds (cf. see the text for definition), the chance in the dark-matter world to form dark-matter galaxies increases. If the dark-matter galaxies would exist in a time span of 1 Gyr, then they might even dictate the formation of the ordinary galaxies (i.e. the dark-matter galaxies get formed first); thus, the implications for the structure of our Universe would be tremendous.
2307.03768
Juan Antonio Aguilar-Saavedra
J. A. Aguilar-Saavedra, H. B. C\^amara, F. R. Joaquim, J. F. Seabra
Confronting the 95 GeV excesses within the UN2HDM
LaTeX 17 pages. Added comments, final version in PRD
null
null
IFT-UAM-CSIC-23-86
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the small excesses around 95 GeV found in several searches for a new scalar in $\gamma \gamma$, $\tau \tau$ and $b \bar b$ final states. Instead of trying to accommodate them all, as is usually done in the literature, in the context of a given Standard Model~(SM) extension, we investigate whether it would be possible that one or two of these excesses correspond to an actual new scalar, while the remaining ones are merely statistical fluctuations. To this end, we use as benchmark model the UN2HDM, a SM extension with one scalar doublet, one scalar singlet, and an extra $\text{U}(1)'$ symmetry, which has been previously studied in the context of multiboson cascade decays. We show that most of the possibilities where the excesses in one or two of these channels disappear in the future can be accommodated by type-I or type-III UN2HDMs.
[ { "created": "Fri, 7 Jul 2023 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 17 Oct 2023 09:46:08 GMT", "version": "v2" } ]
2023-10-18
[ [ "Aguilar-Saavedra", "J. A.", "" ], [ "Câmara", "H. B.", "" ], [ "Joaquim", "F. R.", "" ], [ "Seabra", "J. F.", "" ] ]
We consider the small excesses around 95 GeV found in several searches for a new scalar in $\gamma \gamma$, $\tau \tau$ and $b \bar b$ final states. Instead of trying to accommodate them all, as is usually done in the literature, in the context of a given Standard Model~(SM) extension, we investigate whether it would be possible that one or two of these excesses correspond to an actual new scalar, while the remaining ones are merely statistical fluctuations. To this end, we use as benchmark model the UN2HDM, a SM extension with one scalar doublet, one scalar singlet, and an extra $\text{U}(1)'$ symmetry, which has been previously studied in the context of multiboson cascade decays. We show that most of the possibilities where the excesses in one or two of these channels disappear in the future can be accommodated by type-I or type-III UN2HDMs.
2404.01633
Hao Yang
Hao Yang, Jun Jiang and Bingwei Long
Doubly heavy hadrons production in ultraperipheral collision
22 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the double heavy baryon $\Xi_{QQ'}$ and tetraquark $T_{QQ}$ production through photon-photon and photon-gluon fusion via ultraperipheral collisions at the LHC and FCC within the framework of nonrelativistic QCD factorization formalism. Various ion-ion collisions are taken into account, two cc(bb)-diquark configurations ($[cc(bb),{^3S_1}\mbox{-}\bar{\bm{3}}]$ and $[cc(bb),{^1S_0}\mbox{-}\bm{6}]$) and four bc-diquark configurations ($[bc,{^3S_1}\mbox{-}\bar{\bm{3}}]$, $[bc,{^3S_1}\mbox{-}\bm{6}]$, $[bc,{^1S_0}\mbox{-}\bar{\bm{3}}]$ and $[bc,{^1S_0}\mbox{-}\bm{6}]$) are considered in the calculation. Numerical results indicate that the $[cc,{^3S_1}\mbox{-}\bar{\bm{3}}]$ diquark provides dominant contribution for $\Xi_{cc}$ ($T_{cc}$) production, and a considerable number of $\Xi_{cc}$ ($T_{cc}$) can be produced. Due to the event topologies for ultraperipheral collision are very clear, the background from various QCD interactions can be suppressed, hence the experimental investigation for $\Xi_{cc}$ and $T_{cc}$ are feasible. The productions for $\Xi_{bc/bb}$ are also discussed, leaving only slightly possibility for $\Xi_{bc}$ through photon-gluon fusion with ultraperipheral collisions at the FCC.
[ { "created": "Tue, 2 Apr 2024 04:36:04 GMT", "version": "v1" } ]
2024-04-03
[ [ "Yang", "Hao", "" ], [ "Jiang", "Jun", "" ], [ "Long", "Bingwei", "" ] ]
We study the double heavy baryon $\Xi_{QQ'}$ and tetraquark $T_{QQ}$ production through photon-photon and photon-gluon fusion via ultraperipheral collisions at the LHC and FCC within the framework of nonrelativistic QCD factorization formalism. Various ion-ion collisions are taken into account, two cc(bb)-diquark configurations ($[cc(bb),{^3S_1}\mbox{-}\bar{\bm{3}}]$ and $[cc(bb),{^1S_0}\mbox{-}\bm{6}]$) and four bc-diquark configurations ($[bc,{^3S_1}\mbox{-}\bar{\bm{3}}]$, $[bc,{^3S_1}\mbox{-}\bm{6}]$, $[bc,{^1S_0}\mbox{-}\bar{\bm{3}}]$ and $[bc,{^1S_0}\mbox{-}\bm{6}]$) are considered in the calculation. Numerical results indicate that the $[cc,{^3S_1}\mbox{-}\bar{\bm{3}}]$ diquark provides dominant contribution for $\Xi_{cc}$ ($T_{cc}$) production, and a considerable number of $\Xi_{cc}$ ($T_{cc}$) can be produced. Due to the event topologies for ultraperipheral collision are very clear, the background from various QCD interactions can be suppressed, hence the experimental investigation for $\Xi_{cc}$ and $T_{cc}$ are feasible. The productions for $\Xi_{bc/bb}$ are also discussed, leaving only slightly possibility for $\Xi_{bc}$ through photon-gluon fusion with ultraperipheral collisions at the FCC.
2112.04253
Mattias Sj\"o
Benjamin Alvarez, Johan Bijnens, Mattias Sj\"o
NNLO Positivity Bounds on Chiral Perturbation Theory for a General Number of Flavours
94 pages of which 51 in appendices, 31 figures, 2 tables. Version 2 added to reflect changes (mainly clarifications) done prior to publication in JHEP
null
10.1007/JHEP03(2022)159
LU TP 21-50
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present positivity bounds, derived from the principles of analyticity, unitarity and crossing symmetry, that constrain the low-energy constants of chiral perturbation theory. Bounds are produced for 2, 3 or more flavours in meson-meson scattering with equal meson masses, up to and including next-to-next-to-leading order (NNLO), using the second and higher derivatives of the amplitude. We enhance the bounds by using the most general isospin combinations posible (or higher-flavour counterparts thereof) and by analytically integrating the low-energy range of the discontinuities. In addition, we present a powerful and general mathematical framework for efficiently managing large numbers of positivity bounds.
[ { "created": "Wed, 8 Dec 2021 12:11:39 GMT", "version": "v1" }, { "created": "Fri, 16 Sep 2022 09:09:07 GMT", "version": "v2" } ]
2022-09-19
[ [ "Alvarez", "Benjamin", "" ], [ "Bijnens", "Johan", "" ], [ "Sjö", "Mattias", "" ] ]
We present positivity bounds, derived from the principles of analyticity, unitarity and crossing symmetry, that constrain the low-energy constants of chiral perturbation theory. Bounds are produced for 2, 3 or more flavours in meson-meson scattering with equal meson masses, up to and including next-to-next-to-leading order (NNLO), using the second and higher derivatives of the amplitude. We enhance the bounds by using the most general isospin combinations posible (or higher-flavour counterparts thereof) and by analytically integrating the low-energy range of the discontinuities. In addition, we present a powerful and general mathematical framework for efficiently managing large numbers of positivity bounds.
hep-ph/0406278
Zhe Xu
Zhe Xu and Carsten Greiner
Thermalization of gluons in ultrarelativistic heavy ion collisions by including three-body interactions in a parton cascade
121 pages with 55 figures, revised version. Two eps-figures and comments are added. Formula (54) which has typo in journal version is given correctly
Phys.Rev. C71 (2005) 064901
10.1103/PhysRevC.71.064901
null
hep-ph nucl-ex nucl-th
null
We develop a new 3+1 dimensional Monte Carlo cascade solving the kinetic on-shell Boltzmann equations for partons including the inelastic gg <-> ggg pQCD processes. The back reaction channel is treated -- for the first time -- fully consistently within this scheme. An extended stochastic method is used to solve the collision integral. The frame dependence and convergency are studied for a fixed tube with thermal initial conditions. The detailed numerical analysis shows that the stochastic method is fully covariant and that convergency is achieved more efficiently than within a standard geometrical formulation of the collision term, especially for high gluon interaction rates. The cascade is then applied to simulate parton evolution and to investigate thermalization of gluons for a central Au+Au collision at RHIC energy. For this study the initial conditions are assumed to be generated by independent minijets with p_T > p_0=2 GeV. With that choice it is demonstrated that overall kinetic equilibration is driven mainly by the inelastic processes and is achieved on a scale of 1 fm/c. The further evolution of the expanding gluonic matter in the central region then shows almost an ideal hydrodynamical behavior. In addition, full chemical equilibration of the gluons follows on a longer timescale of about 3 fm/c.
[ { "created": "Thu, 24 Jun 2004 19:15:09 GMT", "version": "v1" }, { "created": "Wed, 8 Jun 2005 10:34:31 GMT", "version": "v2" } ]
2009-11-10
[ [ "Xu", "Zhe", "" ], [ "Greiner", "Carsten", "" ] ]
We develop a new 3+1 dimensional Monte Carlo cascade solving the kinetic on-shell Boltzmann equations for partons including the inelastic gg <-> ggg pQCD processes. The back reaction channel is treated -- for the first time -- fully consistently within this scheme. An extended stochastic method is used to solve the collision integral. The frame dependence and convergency are studied for a fixed tube with thermal initial conditions. The detailed numerical analysis shows that the stochastic method is fully covariant and that convergency is achieved more efficiently than within a standard geometrical formulation of the collision term, especially for high gluon interaction rates. The cascade is then applied to simulate parton evolution and to investigate thermalization of gluons for a central Au+Au collision at RHIC energy. For this study the initial conditions are assumed to be generated by independent minijets with p_T > p_0=2 GeV. With that choice it is demonstrated that overall kinetic equilibration is driven mainly by the inelastic processes and is achieved on a scale of 1 fm/c. The further evolution of the expanding gluonic matter in the central region then shows almost an ideal hydrodynamical behavior. In addition, full chemical equilibration of the gluons follows on a longer timescale of about 3 fm/c.
1711.02180
Tong Li
Yi Cai, Tao Han, Tong Li and Richard Ruiz
Lepton Number Violation: Seesaw Models and Their Collider Tests
92 pages, 43 figures. Invited Article for the 'Frontiers in Physics' Research Topic 'The Physics Associated with Neutrino Masses'
Front.in Phys. 6 (2018) 40
null
PITT-PACC-1712, IPPP/17/74, CoEPP-MN-17-17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Majorana nature of neutrinos is strongly motivated from the theoretical and phenomenological point of view. A plethora of neutrino mass models, known collectively as Seesaw models, exist that could generate both a viable neutrino mass spectrum and mixing pattern. They can also lead to rich, new phenomenology, including lepton number non-conservation as well as new particles, that may be observable at collider experiments. It is therefore vital to search for such new phenomena and the mass scale associated with neutrino mass generation at high energy colliders. In this review, we consider a number of representative Seesaw scenarios as phenomenological benchmarks, including the characteristic Type I, II, and III Seesaw mechanisms, their extensions and hybridizations, as well as radiative constructions. We present new and updated predictions for analyses featuring lepton number violation and expected coverage in the theory parameter space at current and future colliders. We emphasize new production and decay channels, their phenomenological relevance and treatment across different facilities in $e^+e^-$, $e^-p$ and $pp$ collisions, as well as the available Monte Carlo tools available for studying Seesaw partners in collider environments.
[ { "created": "Mon, 6 Nov 2017 21:24:41 GMT", "version": "v1" }, { "created": "Thu, 31 May 2018 10:26:30 GMT", "version": "v2" } ]
2018-06-04
[ [ "Cai", "Yi", "" ], [ "Han", "Tao", "" ], [ "Li", "Tong", "" ], [ "Ruiz", "Richard", "" ] ]
The Majorana nature of neutrinos is strongly motivated from the theoretical and phenomenological point of view. A plethora of neutrino mass models, known collectively as Seesaw models, exist that could generate both a viable neutrino mass spectrum and mixing pattern. They can also lead to rich, new phenomenology, including lepton number non-conservation as well as new particles, that may be observable at collider experiments. It is therefore vital to search for such new phenomena and the mass scale associated with neutrino mass generation at high energy colliders. In this review, we consider a number of representative Seesaw scenarios as phenomenological benchmarks, including the characteristic Type I, II, and III Seesaw mechanisms, their extensions and hybridizations, as well as radiative constructions. We present new and updated predictions for analyses featuring lepton number violation and expected coverage in the theory parameter space at current and future colliders. We emphasize new production and decay channels, their phenomenological relevance and treatment across different facilities in $e^+e^-$, $e^-p$ and $pp$ collisions, as well as the available Monte Carlo tools available for studying Seesaw partners in collider environments.
hep-ph/0504191
Alexander Ilyichev
A.Ilyichev, V.Zykunov
Lowest order QED radiative corrections to longitudinally polarized Moller scattering
10 pages, 7 figures
Phys.Rev. D72 (2005) 033018
10.1103/PhysRevD.72.033018
null
hep-ph
null
The total lowest-order electromagnetic radiative corrections to the observables in Moller scattering of longitudinally polarized electrons have been calculated. The final expressions obtained by the covariant method for the infrared divergency cancellation are free from any unphysical cut-off parameters. Since the calculation is carried out within the ultrarelativistic approximation our result has a compact form that is convenient for computing. Basing on these expressions the FORTRAN code MERA has been developed. Using this code the detailed numerical analysis performed under SLAC (E-158) and JLab kinematic conditions has shown that the radiative corrections are significant and rather sensitive to the value of the missing mass (inelasticity) cuts.
[ { "created": "Thu, 21 Apr 2005 11:14:08 GMT", "version": "v1" }, { "created": "Thu, 8 Sep 2005 19:14:12 GMT", "version": "v2" } ]
2007-05-23
[ [ "Ilyichev", "A.", "" ], [ "Zykunov", "V.", "" ] ]
The total lowest-order electromagnetic radiative corrections to the observables in Moller scattering of longitudinally polarized electrons have been calculated. The final expressions obtained by the covariant method for the infrared divergency cancellation are free from any unphysical cut-off parameters. Since the calculation is carried out within the ultrarelativistic approximation our result has a compact form that is convenient for computing. Basing on these expressions the FORTRAN code MERA has been developed. Using this code the detailed numerical analysis performed under SLAC (E-158) and JLab kinematic conditions has shown that the radiative corrections are significant and rather sensitive to the value of the missing mass (inelasticity) cuts.
1605.07360
Subhadip Mitra
Shashikant R. Dugad, Pankaj Jain, Subhadip Mitra, Prasenjit Sanyal and Ravindra K. Verma
The top threshold effect in the $\gamma\gamma$ production at the LHC
7 pages, 6 figures, 1 table. Updated analysis. The version to appear in EPJC
Eur.Phys.J. C78 (2018) no.9, 715
10.1140/epjc/s10052-018-6188-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the top quark threshold contributions to the $\gamma\gamma$ production at the LHC. They appear when the invariant mass of the photon pair, $M_{\gamma\gamma}$ just exceeds two times the mass of the top quark and induce some feature in the $M_{\gamma\gamma}$ distribution. We determine the magnitude of this threshold effect and characterize this feature with a simple empirical fitting function to show that it is possible to observe this effect at the LHC in future. We also explore some possible improvements that may enhance its significance.
[ { "created": "Tue, 24 May 2016 10:17:18 GMT", "version": "v1" }, { "created": "Thu, 26 May 2016 04:34:24 GMT", "version": "v2" }, { "created": "Thu, 8 Mar 2018 07:36:13 GMT", "version": "v3" }, { "created": "Fri, 24 Aug 2018 06:10:41 GMT", "version": "v4" } ]
2018-09-13
[ [ "Dugad", "Shashikant R.", "" ], [ "Jain", "Pankaj", "" ], [ "Mitra", "Subhadip", "" ], [ "Sanyal", "Prasenjit", "" ], [ "Verma", "Ravindra K.", "" ] ]
We compute the top quark threshold contributions to the $\gamma\gamma$ production at the LHC. They appear when the invariant mass of the photon pair, $M_{\gamma\gamma}$ just exceeds two times the mass of the top quark and induce some feature in the $M_{\gamma\gamma}$ distribution. We determine the magnitude of this threshold effect and characterize this feature with a simple empirical fitting function to show that it is possible to observe this effect at the LHC in future. We also explore some possible improvements that may enhance its significance.
hep-ph/9909288
Cohen Iuliana
Gideon Alexander and Iuliana Cohen
The Source Size Dependence on the M_hadron Applying Fermi and Bose Statistics and I-Spin Invariance
7 pages, 4 figures, Based on an invited talk given by G. Alexander at the XXIX Int. Symp. on Multiparticle Dynamics, 9-13 August 1999, Providence RI, USA. (to be published in the proceedings of this conference)
null
null
TAUP-2598-99
hep-ph
null
The emission volume sizes of pions and Kaons, r_{\pi^\pm \pi^\pm} and r_{K^\pm K^\pm}, measured in the hadronic Z^0 decays via the Bose-Einstein Correlations (BEC), and the recent measurements of r_{\Lambda\Lambda} obtained by through the Pauli exclusion principle are used to study the r dependence on the hadron mass. A clear r_{\pi^\pm \pi^\pm} > r_{K^\pm K^\pm} > r_{\Lambda \Lambda} hierarchy is observed which seems to disagree with the basic string (LUND) model expectation. An adequate description of r(m) is obtained via the Heisenberg uncertainty relations and also by Local Parton Hadron Duality approach using a general QCD potential. These lead to a relation of the type r(m) ~ Constant/sqrt{m}. The present lack of knowledge on the f_o(980) decay rate to the K^0\bar{K}^0 channel prohibits the use of the r_{K^0_SK^0_S} in the r(m) analysis. The use of a generalised BEC and I-spin invariance, which predicts an BEC enhancement also in the K^{\pm}K^0 and \pi^{\pm}\pi^0 systems, should in the future help to include the r_{K^0_SK^0_S} in the r(m) analysis.
[ { "created": "Wed, 8 Sep 1999 14:27:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Alexander", "Gideon", "" ], [ "Cohen", "Iuliana", "" ] ]
The emission volume sizes of pions and Kaons, r_{\pi^\pm \pi^\pm} and r_{K^\pm K^\pm}, measured in the hadronic Z^0 decays via the Bose-Einstein Correlations (BEC), and the recent measurements of r_{\Lambda\Lambda} obtained by through the Pauli exclusion principle are used to study the r dependence on the hadron mass. A clear r_{\pi^\pm \pi^\pm} > r_{K^\pm K^\pm} > r_{\Lambda \Lambda} hierarchy is observed which seems to disagree with the basic string (LUND) model expectation. An adequate description of r(m) is obtained via the Heisenberg uncertainty relations and also by Local Parton Hadron Duality approach using a general QCD potential. These lead to a relation of the type r(m) ~ Constant/sqrt{m}. The present lack of knowledge on the f_o(980) decay rate to the K^0\bar{K}^0 channel prohibits the use of the r_{K^0_SK^0_S} in the r(m) analysis. The use of a generalised BEC and I-spin invariance, which predicts an BEC enhancement also in the K^{\pm}K^0 and \pi^{\pm}\pi^0 systems, should in the future help to include the r_{K^0_SK^0_S} in the r(m) analysis.
hep-ph/0703107
Yukihiro Mimura
Ilia Gogoladze, Chin-Aik Lee, Yukihiro Mimura and Qaisar Shafi
Yukawa Couplings in a Model with Gauge, Higgs and Matter Unification
12 pages
Phys.Lett.B649:212-217,2007
10.1016/j.physletb.2007.03.042
MIFP-07-07
hep-ph
null
We discuss how unification of the gauge, Higgs and (three chiral family) matter superfields can be realized from the compactification of a six dimensional supersymmetric SU(8) gauge theory over the orbifold R^4 x T^2/Z_3. The bulk gauge interaction includes Yukawa interactions to generate masses for quarks and leptons after the electroweak symmetry is broken. The Yukawa matrices in this case turn out to be antisymmetric, and thus not phenomenologically viable. To overcome this we introduce brane fields which are vector-like under the standard model gauge symmetry, and so do not alter the number of chiral families. In such a setup, the observed fermion masses and mixings can be realized by taking into account suppression effects from the effective Wilson line couplings and large volume of the extra dimensions.
[ { "created": "Fri, 9 Mar 2007 20:46:32 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gogoladze", "Ilia", "" ], [ "Lee", "Chin-Aik", "" ], [ "Mimura", "Yukihiro", "" ], [ "Shafi", "Qaisar", "" ] ]
We discuss how unification of the gauge, Higgs and (three chiral family) matter superfields can be realized from the compactification of a six dimensional supersymmetric SU(8) gauge theory over the orbifold R^4 x T^2/Z_3. The bulk gauge interaction includes Yukawa interactions to generate masses for quarks and leptons after the electroweak symmetry is broken. The Yukawa matrices in this case turn out to be antisymmetric, and thus not phenomenologically viable. To overcome this we introduce brane fields which are vector-like under the standard model gauge symmetry, and so do not alter the number of chiral families. In such a setup, the observed fermion masses and mixings can be realized by taking into account suppression effects from the effective Wilson line couplings and large volume of the extra dimensions.
hep-ph/0410331
Kang Young Lee
C.S. Kim (Yonsei U.), Yeong Gyun Kim (Korea U.), and Kang Young Lee (KAIST)
Implication of the weak phase $\beta$ measured in $B \to \rho \gamma$ decay
4 pages, talk given at the 32nd International Conference on High Energy Physics (ICHEP'04), Beijing, China, 16-22 Aug. 2004
null
10.1142/9789812702227_0159
KAIST-TH 2004/08
hep-ph
null
We explore the exclusive $ B^0 \to \rho^0 \gamma$ decay to obtain the time-dependent CP asymmetry in $b \to d \gamma$ decay process. We find that the complex RL and RR mass insertion to the squark sector in the MSSM can lead to a large deviation of CP asymmetry from that predicted in the Standard Model.
[ { "created": "Mon, 25 Oct 2004 12:46:30 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kim", "C. S.", "", "Yonsei U." ], [ "Kim", "Yeong Gyun", "", "Korea U." ], [ "Lee", "Kang Young", "", "KAIST" ] ]
We explore the exclusive $ B^0 \to \rho^0 \gamma$ decay to obtain the time-dependent CP asymmetry in $b \to d \gamma$ decay process. We find that the complex RL and RR mass insertion to the squark sector in the MSSM can lead to a large deviation of CP asymmetry from that predicted in the Standard Model.
2207.13044
Shahin Atashbar Tehrani
Fatemeh Arbabifar, Shahin Atashbar Tehrani
The effect of light sea quark symmetry breaking on polarized nucleus and sum rules
4 pages, 2 figures ,41st International Conference on High Energy physics - ICHEP2022,6-13 July 2022,Bologna, Italy
PoS(ICHEP2022)1170
10.22323/1.414.1170
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The polarized structure functions of $^3He$ and $^3H$ nuclei are calculated in NLO approximation, considering and disregarding the light sea quark symmetry breaking. We employ the polarized structure function of the nucleons within the nucleus extracted from our two recent analysis on polarized DIS data and on polarized DIS+SIDIS data. Since the data of the second analysis cover a bigger range of Bjorken variable, both SU(2) and SU(3) symmetry breaking is considered within the analysis. Then we calculate and compare the polarized structures of nuclei extracted from both scenarios. Also the Bjorken and ELT sum rules are calculated using the moments of structure functions. The results are compared with experimental data and the differences are investigated.
[ { "created": "Tue, 26 Jul 2022 17:06:20 GMT", "version": "v1" } ]
2022-08-29
[ [ "Arbabifar", "Fatemeh", "" ], [ "Tehrani", "Shahin Atashbar", "" ] ]
The polarized structure functions of $^3He$ and $^3H$ nuclei are calculated in NLO approximation, considering and disregarding the light sea quark symmetry breaking. We employ the polarized structure function of the nucleons within the nucleus extracted from our two recent analysis on polarized DIS data and on polarized DIS+SIDIS data. Since the data of the second analysis cover a bigger range of Bjorken variable, both SU(2) and SU(3) symmetry breaking is considered within the analysis. Then we calculate and compare the polarized structures of nuclei extracted from both scenarios. Also the Bjorken and ELT sum rules are calculated using the moments of structure functions. The results are compared with experimental data and the differences are investigated.
1903.10552
Juan Herrero-Garcia
Juan Herrero-Garcia and Michael A. Schmidt
Neutrino mass models: New classification and model-independent upper limits on their scale
10 pages, 1 table, 1 figure; title changed, discussions extended, figure updated, matches published version in EPJC
null
10.1140/epjc/s10052-019-7465-1
SISSA 07/2019/FISI
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model-independent framework to classify and study neutrino mass models and their phenomenology. The idea is to introduce one particle beyond the Standard Model which couples to leptons and carries lepton number together with an operator which violates lepton number by two units and contains this particle. This allows to study processes which do not violate lepton number, while still working with an effective field theory. The contribution to neutrino masses translates to a robust upper bound on the mass of the new particle. We compare it to the stronger but less robust upper bound from Higgs naturalness and discuss several lower bounds. Our framework allows to classify neutrino mass models in \emph{just} 20 categories, further reduced to 14 once nucleon decay limits are taken into account, and \emph{possibly} to 9 if also Higgs naturalness considerations and direct searches are considered.
[ { "created": "Mon, 25 Mar 2019 19:00:11 GMT", "version": "v1" }, { "created": "Mon, 18 Nov 2019 13:05:46 GMT", "version": "v2" } ]
2020-01-08
[ [ "Herrero-Garcia", "Juan", "" ], [ "Schmidt", "Michael A.", "" ] ]
We propose a model-independent framework to classify and study neutrino mass models and their phenomenology. The idea is to introduce one particle beyond the Standard Model which couples to leptons and carries lepton number together with an operator which violates lepton number by two units and contains this particle. This allows to study processes which do not violate lepton number, while still working with an effective field theory. The contribution to neutrino masses translates to a robust upper bound on the mass of the new particle. We compare it to the stronger but less robust upper bound from Higgs naturalness and discuss several lower bounds. Our framework allows to classify neutrino mass models in \emph{just} 20 categories, further reduced to 14 once nucleon decay limits are taken into account, and \emph{possibly} to 9 if also Higgs naturalness considerations and direct searches are considered.
2112.06093
Anna Danilina
A. V. Danilina, N. V. Nikitin
Rare decays of the $B_s-$meson into four charged leptons in the framework of the Standard Model
null
null
10.1088/1402-4896/ac7422
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the Standard Model we present new theoretical predictions for the branching ratios, double and single differential distributions and forward -- backward leptonic asymmetries for the $\bar B_s \to \mu^+ \mu^- e^+ e^-$ decay. In our consideration we take into account the $\phi(1020)$ -- resonance contribution; the main contributions of four charmonium resonances : $\psi(3770)$, $\psi(4040)$, $\psi(4160)$ and $\psi(4415)$; $u\bar{u}$ -- resonant contribution from $\rho(770)$ and $\omega(782)$; tails contributions from $J/\psi$ and $\psi(2S)$ resonances; non -- resonant contribution of the $b\,\bar{b}$ - pairs, bremsstrahlung and the contribution of the weak annihilation. We provide the prediction for the branching ratio of $\bar B_s \to \mu^+ \mu^- e^+ e^-$ decay with and without the $\phi(1020)$ -- resonance contribution. We use the model of vector meson dominance (VMD) for calculation of resonances contributions and take into account all substantive terms in $\bar B_s \to \mu^+ \mu^- e^+ e^-$ amplitude that was not considered in the previously papers.
[ { "created": "Sat, 11 Dec 2021 23:17:18 GMT", "version": "v1" } ]
2022-06-22
[ [ "Danilina", "A. V.", "" ], [ "Nikitin", "N. V.", "" ] ]
In the framework of the Standard Model we present new theoretical predictions for the branching ratios, double and single differential distributions and forward -- backward leptonic asymmetries for the $\bar B_s \to \mu^+ \mu^- e^+ e^-$ decay. In our consideration we take into account the $\phi(1020)$ -- resonance contribution; the main contributions of four charmonium resonances : $\psi(3770)$, $\psi(4040)$, $\psi(4160)$ and $\psi(4415)$; $u\bar{u}$ -- resonant contribution from $\rho(770)$ and $\omega(782)$; tails contributions from $J/\psi$ and $\psi(2S)$ resonances; non -- resonant contribution of the $b\,\bar{b}$ - pairs, bremsstrahlung and the contribution of the weak annihilation. We provide the prediction for the branching ratio of $\bar B_s \to \mu^+ \mu^- e^+ e^-$ decay with and without the $\phi(1020)$ -- resonance contribution. We use the model of vector meson dominance (VMD) for calculation of resonances contributions and take into account all substantive terms in $\bar B_s \to \mu^+ \mu^- e^+ e^-$ amplitude that was not considered in the previously papers.
1503.03328
Joaquim Matias
Sebastien Descotes-Genon, Lars Hofer, Joaquim Matias, Javier Virto
Theoretical status of $B \to K^* \mu^+\mu^-$: The path towards New Physics
17 pages, 1 figure. Talk given at the Discrete 2014: Fourth Symposium on Prospects in the Physics of Discrete Symmetries
null
10.1088/1742-6596/631/1/012027
QFET-2015-22
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We summarize the status of the analysis of the 4-body angular distribution $B \to K^*(\to K \pi) \mu^+\mu^-$ using a basis of optimized observables. We provide a New Physics interpretation of the pattern of deviations observed in the 1fb$^{-1}$ dataset with the coefficient of the semileptonic operator $O_9$ being the main responsible for this pattern. Also other scenarios involving more Wilson coefficients are briefly discussed. Further, we present a detailed description of each of the hadronic uncertainties entering our predictions and suggest possible tests for alternative hadronic explanations. Our most accurate SM predictions for the optimized observables in various bins including all uncertainties are also provided.
[ { "created": "Wed, 11 Mar 2015 13:42:09 GMT", "version": "v1" } ]
2015-09-02
[ [ "Descotes-Genon", "Sebastien", "" ], [ "Hofer", "Lars", "" ], [ "Matias", "Joaquim", "" ], [ "Virto", "Javier", "" ] ]
We summarize the status of the analysis of the 4-body angular distribution $B \to K^*(\to K \pi) \mu^+\mu^-$ using a basis of optimized observables. We provide a New Physics interpretation of the pattern of deviations observed in the 1fb$^{-1}$ dataset with the coefficient of the semileptonic operator $O_9$ being the main responsible for this pattern. Also other scenarios involving more Wilson coefficients are briefly discussed. Further, we present a detailed description of each of the hadronic uncertainties entering our predictions and suggest possible tests for alternative hadronic explanations. Our most accurate SM predictions for the optimized observables in various bins including all uncertainties are also provided.
hep-ph/9812296
Gogberashvili Merab Jakob
Merab Gogberashvili (Tbilisi Institute of Physics)
Hierarchy problem in the shell-Universe model
2 pages, RevTeX
Int.J.Mod.Phys. D11 (2002) 1635-1638
10.1142/S0218271802002992
null
hep-ph gr-qc hep-th
null
In the model where the Universe is considered as a thin shell expanding in 5-dimensional hyper-space there is a possibility to obtain one scale for particle theory corresponding to the 5-dimensional cosmological constant and Universe thickness.
[ { "created": "Wed, 9 Dec 1998 15:04:50 GMT", "version": "v1" } ]
2009-10-31
[ [ "Gogberashvili", "Merab", "", "Tbilisi Institute of Physics" ] ]
In the model where the Universe is considered as a thin shell expanding in 5-dimensional hyper-space there is a possibility to obtain one scale for particle theory corresponding to the 5-dimensional cosmological constant and Universe thickness.
1603.02203
Kazuki Sakurai
Marcin Badziak, Marek Olechowski, Stefan Pokorski and Kazuki Sakurai
Interpreting 750 GeV Diphoton Excess in Plain NMSSM
20 pages, 6 figures, typos have been corrected, a study about the radiative correction to the Higgs boson mass has been added
null
10.1016/j.physletb.2016.06.057
IPPP/16/17
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
NMSSM has enough ingredients to explain the diphoton excess at 750 GeV: singlet-like (pseudo) scalar ($a$) $s$ and higgsinos as heavy vector-like fermions. We consider the production of the 750 GeV singlet-like pseudo scalar a from a decay of the doublet-like pseudo scalar $A$, and the subsequent decay of $a$ into two photons via higgsino loop. We demonstrate that this cascade decay of the NMSSM Higgs bosons can explain the diphoton excess in the 13 TeV data consistently with the absence of a significant excess in the 8 TeV data.
[ { "created": "Mon, 7 Mar 2016 18:55:15 GMT", "version": "v1" }, { "created": "Mon, 4 Jul 2016 23:00:05 GMT", "version": "v2" } ]
2016-08-03
[ [ "Badziak", "Marcin", "" ], [ "Olechowski", "Marek", "" ], [ "Pokorski", "Stefan", "" ], [ "Sakurai", "Kazuki", "" ] ]
NMSSM has enough ingredients to explain the diphoton excess at 750 GeV: singlet-like (pseudo) scalar ($a$) $s$ and higgsinos as heavy vector-like fermions. We consider the production of the 750 GeV singlet-like pseudo scalar a from a decay of the doublet-like pseudo scalar $A$, and the subsequent decay of $a$ into two photons via higgsino loop. We demonstrate that this cascade decay of the NMSSM Higgs bosons can explain the diphoton excess in the 13 TeV data consistently with the absence of a significant excess in the 8 TeV data.
1102.2499
Mojtaba Mohammadi Najafabadi
S. Batebi, S. M. Etesami and M. Mohammadi Najafabadi
The Angular Correlations in Top Quark Decays in Standard Model Extensions
5 figures
Phys.Rev.D83:057502,2011; Publisher-note D83:059901,2011; Phys.Rev.D83:059901,2011
10.1103/PhysRevD.83.057502 10.1103/PhysRevD.83.059901
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CMS collaboration at the CERN-LHC have searched for the $t$-channel single top quark production using the spin correlation of the $t$-channel. The signal extraction and cross section measurement relies on the angular distribution of the charged lepton in the top quark decays, the angle between the charged lepton momentum and top spin in the top rest frame. The behavior of the angular distribution is a distinct slope for the t-channel single top (signal) while it is flat for the backgrounds. In this letter we investigate the contributions which this spin correlation may receive from a two-Higgs doublet model, a top-color assisted technicolor (TC2) and the noncommutative extension of the Standard Model.
[ { "created": "Sat, 12 Feb 2011 11:31:12 GMT", "version": "v1" } ]
2011-05-12
[ [ "Batebi", "S.", "" ], [ "Etesami", "S. M.", "" ], [ "Najafabadi", "M. Mohammadi", "" ] ]
The CMS collaboration at the CERN-LHC have searched for the $t$-channel single top quark production using the spin correlation of the $t$-channel. The signal extraction and cross section measurement relies on the angular distribution of the charged lepton in the top quark decays, the angle between the charged lepton momentum and top spin in the top rest frame. The behavior of the angular distribution is a distinct slope for the t-channel single top (signal) while it is flat for the backgrounds. In this letter we investigate the contributions which this spin correlation may receive from a two-Higgs doublet model, a top-color assisted technicolor (TC2) and the noncommutative extension of the Standard Model.
hep-ph/9502393
Johan Bijnens
Johan Bijnens (NORDITA)
Chiral Perturbation Theory
19 pages, 4 postscript figures (included), LaTeX, uses epsf.sty
null
null
NORDITA - 95/12 N,P
hep-ph nucl-th
null
A short overview of the current state of Chiral Perturbation Theory is given. This includes a description of the basic assumptions, the usefulness of the external field method is emphasized using a simple lowest order example. Then at next-to-leading order the determination of the parameters is discussed. We also present the status of calculations at ${\cal O}(p^6)$. Finally I present the extension into 3 directions: estimates of the free parameters, inclusion of nonleptonic weak and electromagnetic interactions, and inclusion of non-Goldstone fields in the chiral Lagrangian. Invited Talk at the International Workshop on Nuclear \& Particle Physics ``Chiral Dynamics in Hadrons \& Nuclei,'' Feb 6 $\sim$ Feb 10, 1995, Seoul, Korea.
[ { "created": "Mon, 27 Feb 1995 14:28:16 GMT", "version": "v1" } ]
2016-09-01
[ [ "Bijnens", "Johan", "", "NORDITA" ] ]
A short overview of the current state of Chiral Perturbation Theory is given. This includes a description of the basic assumptions, the usefulness of the external field method is emphasized using a simple lowest order example. Then at next-to-leading order the determination of the parameters is discussed. We also present the status of calculations at ${\cal O}(p^6)$. Finally I present the extension into 3 directions: estimates of the free parameters, inclusion of nonleptonic weak and electromagnetic interactions, and inclusion of non-Goldstone fields in the chiral Lagrangian. Invited Talk at the International Workshop on Nuclear \& Particle Physics ``Chiral Dynamics in Hadrons \& Nuclei,'' Feb 6 $\sim$ Feb 10, 1995, Seoul, Korea.
2401.00250
Guilherme Zeminiani
G. N. Zeminiani, S. L. P. G. Beres, K. Tsushima
In-medium mass shift of two-flavored heavy mesons, $B_c$, $B^*_c$, $B_s$, $B^*_s$, $D_s$ and $D^*_s$
21 pages, 19 figures (39 .eps files for figures), changes: unnecessary files removed, 1 figure corrected
null
null
LFTC-23-10/83
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
For the first time, we estimate the in-medium mass shift of the two-flavored heavy mesons $B_c, B_c^*, B_s, B_s^*, D_s$ and $D_s^*$ in symmetric nuclear matter. The estimates are made by evaluating the lowest order one-loop self-energies. The enhanced excitations of intermediate state heavy-light mesons in symmetric nuclear matter are the origin of their negative mass shift. Our results show that the magnitude of the mass shift for the $B_c$ meson ($\bar{b} c$ or $b \bar{c}$) is larger than those of the $\eta_c (\bar{c} c)$ and $\eta_b (\bar{b} b)$, different from a naive expectation that it would be in-between of them. While, that of the $B_c^*$ shows the in-between of the $J/\psi$ and $\Upsilon$. We observe that the lighter vector meson excitation in each meson self-energy gives a dominant contribution for the corresponding meson mass shift, $B_c, B_s,$ and $D_s$.
[ { "created": "Sat, 30 Dec 2023 14:36:11 GMT", "version": "v1" }, { "created": "Wed, 3 Jan 2024 02:22:05 GMT", "version": "v2" } ]
2024-01-04
[ [ "Zeminiani", "G. N.", "" ], [ "Beres", "S. L. P. G.", "" ], [ "Tsushima", "K.", "" ] ]
For the first time, we estimate the in-medium mass shift of the two-flavored heavy mesons $B_c, B_c^*, B_s, B_s^*, D_s$ and $D_s^*$ in symmetric nuclear matter. The estimates are made by evaluating the lowest order one-loop self-energies. The enhanced excitations of intermediate state heavy-light mesons in symmetric nuclear matter are the origin of their negative mass shift. Our results show that the magnitude of the mass shift for the $B_c$ meson ($\bar{b} c$ or $b \bar{c}$) is larger than those of the $\eta_c (\bar{c} c)$ and $\eta_b (\bar{b} b)$, different from a naive expectation that it would be in-between of them. While, that of the $B_c^*$ shows the in-between of the $J/\psi$ and $\Upsilon$. We observe that the lighter vector meson excitation in each meson self-energy gives a dominant contribution for the corresponding meson mass shift, $B_c, B_s,$ and $D_s$.
hep-ph/9607345
Roland Hoepker
R. H\"opker (DESY) and W. Beenakker (Univ. Leiden)
Cross-sections for squark and gluino production at hadron colliders
7 pages Latex, uses psfig.sty and sprocl.sty, 6 eps figures and sprocl.sty appended as uuencoded, gzipped, tarred file. Invited talk at the 11th Topical Workshop on P-Pbar Collider Physics, Abano Terme, Italy, 26 May - 1 June 1996
null
null
null
hep-ph
null
We present the cross-sections for the hadroproduction of squarks and gluinos in next-to-leading order of supersymmetric QCD. The four possible final states squark-antisquark, squark-squark, gluino-gluino and squark-gluino are analysed for the hadron colliders Tevatron and LHC. The dependence of the cross-sections on the renormalization and factorization scale is reduced significantly. The shape of the transverse-momentum and rapidity distributions remains nearly unchanged when the next-to-leading order SUSY-QCD contributions are included. The size of the corrections at the central scale, given by the average mass of the produced particles, varies between $+5\%$ and $+90\%$.
[ { "created": "Wed, 17 Jul 1996 07:31:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Höpker", "R.", "", "DESY" ], [ "Beenakker", "W.", "", "Univ. Leiden" ] ]
We present the cross-sections for the hadroproduction of squarks and gluinos in next-to-leading order of supersymmetric QCD. The four possible final states squark-antisquark, squark-squark, gluino-gluino and squark-gluino are analysed for the hadron colliders Tevatron and LHC. The dependence of the cross-sections on the renormalization and factorization scale is reduced significantly. The shape of the transverse-momentum and rapidity distributions remains nearly unchanged when the next-to-leading order SUSY-QCD contributions are included. The size of the corrections at the central scale, given by the average mass of the produced particles, varies between $+5\%$ and $+90\%$.
2108.13020
Shu-Sheng Xu
Shu-Sheng Xu
Phase structures of neutral dense quark matter and application to strange stars
To be published in Chinese Physics C
null
10.1088/1674-1137/ac2f95
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the contact interaction model, the quark propagator has only one solution, chiral symmetry breaking solution, at vanish temperature and density. Inspire by Y. Jiang and Z.-F. Cui, we introduce 2+1 flavors quark condensates feedback on coupling strength, the Wigner solution appears in some region of parameters. It enables us to tackle chiral phase transition as two-phase coexistences. At finite chemical potential, we analyze the chiral phase transition to the conditions of electric charge neutrality and $\beta$ equilibrium. The four chemical potentials, $\mu_u$, $\mu_d$, $\mu_s$ and $\mu_e$, are constrained by three conditions, there is one independent variable that remained, we choose the average quark chemical potential as the free variable. All quark masses and number densities suffer discontinuities at the phase transition point. The strange quarks appear after the phase transition due to the system needs more energy to produce a d-quark than an s-quark. Take the EOS as an input, the TOV equations are solved numerically, we show that the mass-radius relation is sensitive to the EOSs. The maximum mass of strange quark stars is not susceptible to our introduced parameter $\Lambda_q$.
[ { "created": "Mon, 30 Aug 2021 07:02:56 GMT", "version": "v1" }, { "created": "Thu, 14 Oct 2021 10:50:06 GMT", "version": "v2" } ]
2021-10-15
[ [ "Xu", "Shu-Sheng", "" ] ]
In the contact interaction model, the quark propagator has only one solution, chiral symmetry breaking solution, at vanish temperature and density. Inspire by Y. Jiang and Z.-F. Cui, we introduce 2+1 flavors quark condensates feedback on coupling strength, the Wigner solution appears in some region of parameters. It enables us to tackle chiral phase transition as two-phase coexistences. At finite chemical potential, we analyze the chiral phase transition to the conditions of electric charge neutrality and $\beta$ equilibrium. The four chemical potentials, $\mu_u$, $\mu_d$, $\mu_s$ and $\mu_e$, are constrained by three conditions, there is one independent variable that remained, we choose the average quark chemical potential as the free variable. All quark masses and number densities suffer discontinuities at the phase transition point. The strange quarks appear after the phase transition due to the system needs more energy to produce a d-quark than an s-quark. Take the EOS as an input, the TOV equations are solved numerically, we show that the mass-radius relation is sensitive to the EOSs. The maximum mass of strange quark stars is not susceptible to our introduced parameter $\Lambda_q$.
1009.3740
Thorsten Renk
Thorsten Renk
YaJEM - a Monte Carlo code for in-medium shower evolution
Talk given at the workshop 'Jets in Proton-Proton and Heavy-Ion Collisions', Prague, Czech Republic, 12-14 Aug 2010
null
10.1142/S0218301311019933
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High transverse momentum (P_T) QCD scattering processes are regarded as a valuable tool to study the medium produced in heavy-ion collisions, as due to uncertainty arguments their cross section should be calculable independent of medium properties whereas the medium then modifies only the final state partons emerging from a hard vertex. With the heavy-ion physics program at the CERN LHC imminent, the attention of high P_T physics in heavy ion collisions is shifting from the observation of hard single hadrons to fully reconstructed jets. However, the presence of a background medium at low P_T complicates jet-finding as compared to p-p collisions. Monte-Carlo (MC) codes designed to simulate the evolution of parton showers evolving into hadron jets are valuable tools to understand the complicated interplay between the medium modification of the jet and the bias introduced by a specific jet-finding scheme. However, such codes also use a set of approximations which needs to be tested against the better understood single high P_T hadron observables. In this paper, I review the ideas underlying the MC code YaJEM (Yet another Jet Energy-loss Model) and present some of the results obtained with the code.
[ { "created": "Mon, 20 Sep 2010 09:11:18 GMT", "version": "v1" } ]
2015-05-20
[ [ "Renk", "Thorsten", "" ] ]
High transverse momentum (P_T) QCD scattering processes are regarded as a valuable tool to study the medium produced in heavy-ion collisions, as due to uncertainty arguments their cross section should be calculable independent of medium properties whereas the medium then modifies only the final state partons emerging from a hard vertex. With the heavy-ion physics program at the CERN LHC imminent, the attention of high P_T physics in heavy ion collisions is shifting from the observation of hard single hadrons to fully reconstructed jets. However, the presence of a background medium at low P_T complicates jet-finding as compared to p-p collisions. Monte-Carlo (MC) codes designed to simulate the evolution of parton showers evolving into hadron jets are valuable tools to understand the complicated interplay between the medium modification of the jet and the bias introduced by a specific jet-finding scheme. However, such codes also use a set of approximations which needs to be tested against the better understood single high P_T hadron observables. In this paper, I review the ideas underlying the MC code YaJEM (Yet another Jet Energy-loss Model) and present some of the results obtained with the code.
1102.3557
Wang Qing
Feng-Jun Ge, Shao-Zhou Jiang, Qing Wang
Electroweak Chiral Lagrangian from TC2 Model with nontrivial TC fermion condensation and walking
52 pages, 27 figures
Phys.Rev.D84:015009,2011
10.1103/PhysRevD.84.015009
TUHEP-TH-11175
hep-ph
http://creativecommons.org/licenses/by/3.0/
The electroweak chiral Lagrangian for the topcolor assisted technicolor model proposed by K. Lane, which uses nontrivial patterns of techniquark condensation and walking, was investigated in this study. We found that the features of the model are qualitatively similar to those of Lane's previous natural TC2 prototype model, but there is no limit on the upper bound of the Z' mass. We discuss the phase structure and possible walking behavior of the model. We obtained the values of all coefficients of the electroweak chiral Lagrangian up to an order of p4. We show that although the walking effect reduces the S parameter to half its original value, it maintains an order of 2. Moreover, a special hyper-charge arrangement is needed to achieve further reductions in its value.
[ { "created": "Thu, 17 Feb 2011 10:58:27 GMT", "version": "v1" }, { "created": "Fri, 8 Apr 2011 04:43:32 GMT", "version": "v2" }, { "created": "Fri, 29 Apr 2011 18:42:26 GMT", "version": "v3" } ]
2015-03-19
[ [ "Ge", "Feng-Jun", "" ], [ "Jiang", "Shao-Zhou", "" ], [ "Wang", "Qing", "" ] ]
The electroweak chiral Lagrangian for the topcolor assisted technicolor model proposed by K. Lane, which uses nontrivial patterns of techniquark condensation and walking, was investigated in this study. We found that the features of the model are qualitatively similar to those of Lane's previous natural TC2 prototype model, but there is no limit on the upper bound of the Z' mass. We discuss the phase structure and possible walking behavior of the model. We obtained the values of all coefficients of the electroweak chiral Lagrangian up to an order of p4. We show that although the walking effect reduces the S parameter to half its original value, it maintains an order of 2. Moreover, a special hyper-charge arrangement is needed to achieve further reductions in its value.
1507.06224
Jessica Turner
Jessica Turner
Predictions for Leptonic Mixing Angle Correlations and Non-trivial Dirac CP Violation from $A_5$ with Generalised CP Symmetry
null
Phys. Rev. D 92, 116007 (2015)
10.1103/PhysRevD.92.116007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using discrete flavour group, $A_5$, combined with generalised CP, we study the mixing parameter correlations which arise from breaking to residual symmetries in the neutrino, $G_{\nu}=\mathbb{Z}_2\times \text{CP}$, and charged lepton sectors, $G_{e}=\mathbb{Z}_2$. By focusing on patterns that agree with current experimental data we demonstrate that non-trivial leptonic phases are predicted and discuss a number of distinctive correlations between mixing parameters.
[ { "created": "Wed, 22 Jul 2015 15:15:29 GMT", "version": "v1" } ]
2015-12-23
[ [ "Turner", "Jessica", "" ] ]
Using discrete flavour group, $A_5$, combined with generalised CP, we study the mixing parameter correlations which arise from breaking to residual symmetries in the neutrino, $G_{\nu}=\mathbb{Z}_2\times \text{CP}$, and charged lepton sectors, $G_{e}=\mathbb{Z}_2$. By focusing on patterns that agree with current experimental data we demonstrate that non-trivial leptonic phases are predicted and discuss a number of distinctive correlations between mixing parameters.
hep-ph/9906529
Yue-Liang Wu
W.Y. Wang, Y.L. Wu and Y.A. Yan
Weak Matrix Elements and |V_cb| in New Formulation of Heavy Quark Effective Field Theory
28 pages, Revtex, 5 figures, 3 tables, minor changes with "dressed heavy quark" being addressed, to be published in Int. J. Mod. Phys. A
Int.J.Mod.Phys. A15 (2000) 1817-1857
10.1142/S0217751X00000793
AS-ITP 99-06
hep-ph
null
The heavy quark effective field theory (HQEFT) containing both effective `quark fields' and `antiquark fields' is investigated in detail. By integrating out (but not neglecting) the effective antiquark fields, we present a new formulation of effective theory which differs from the usual heavy quark effective theory (HQET) and exhibits valuable features because of the inclusion of the contributions from the antiquark fields. Matrix elements of vector and axial vector heavy quark currents between pseudoscalar and vector mesons containing a heavy quark (b or c) are then evaluated systematically up to the order of $1/m^2_Q$ and parameterized by a set of universal form factors. With a consistent normalization condition between the effective heavy hadron states, the form factors at zero recoil are related to the ground state meson masses, which enables us to estimate the values of form factors at zero recoil. In particular, the Luke's theorem comes out automatically in the new formulation of HQEFT without the need of imposing the equation of motion $iv\cdot D Q^{+}_{v} =0$. Consequently, the differential decay rates of both $B\to D^{\ast}l\nu$ and $B\to D l\nu$ do not receive $1/m_{Q}$ order corrections at zero recoil, which is not the case in the usual HQET. Thus we quote that the Cabibbo-Kobayashi-Maskawa matrix element $| V_{cb}|$ can nicely be extracted from either of these two exclusive semileptonic decays at the order of $1/m^2_Q$. Our estimates for $|V_{cb}|$ are presented.
[ { "created": "Tue, 29 Jun 1999 06:33:04 GMT", "version": "v1" }, { "created": "Thu, 1 Jul 1999 04:06:38 GMT", "version": "v2" }, { "created": "Tue, 1 Feb 2000 08:54:38 GMT", "version": "v3" } ]
2009-10-31
[ [ "Wang", "W. Y.", "" ], [ "Wu", "Y. L.", "" ], [ "Yan", "Y. A.", "" ] ]
The heavy quark effective field theory (HQEFT) containing both effective `quark fields' and `antiquark fields' is investigated in detail. By integrating out (but not neglecting) the effective antiquark fields, we present a new formulation of effective theory which differs from the usual heavy quark effective theory (HQET) and exhibits valuable features because of the inclusion of the contributions from the antiquark fields. Matrix elements of vector and axial vector heavy quark currents between pseudoscalar and vector mesons containing a heavy quark (b or c) are then evaluated systematically up to the order of $1/m^2_Q$ and parameterized by a set of universal form factors. With a consistent normalization condition between the effective heavy hadron states, the form factors at zero recoil are related to the ground state meson masses, which enables us to estimate the values of form factors at zero recoil. In particular, the Luke's theorem comes out automatically in the new formulation of HQEFT without the need of imposing the equation of motion $iv\cdot D Q^{+}_{v} =0$. Consequently, the differential decay rates of both $B\to D^{\ast}l\nu$ and $B\to D l\nu$ do not receive $1/m_{Q}$ order corrections at zero recoil, which is not the case in the usual HQET. Thus we quote that the Cabibbo-Kobayashi-Maskawa matrix element $| V_{cb}|$ can nicely be extracted from either of these two exclusive semileptonic decays at the order of $1/m^2_Q$. Our estimates for $|V_{cb}|$ are presented.
hep-ph/9810273
Nguyen Anh Ky
Nguyen Tuan Anh, Nguyen Anh Ky and Hoang Ngoc Long
The Higgs Sector of the Minimal 3 3 1 Model Revisited
20 pages, latex, two figures. One note and one reference are added
Int.J.Mod.PHys.A15:283-305,2000
10.1142/S0217751X00000136
LAPTH-701/98
hep-ph astro-ph
null
The mass spectrum and the eigenstates of the Higgs sector of the minimal 3 3 1 model are revisited in detail. There are discrepancies between our results and previous results by another author.
[ { "created": "Wed, 7 Oct 1998 15:28:20 GMT", "version": "v1" }, { "created": "Thu, 15 Oct 1998 12:42:59 GMT", "version": "v2" } ]
2009-10-31
[ [ "Anh", "Nguyen Tuan", "" ], [ "Ky", "Nguyen Anh", "" ], [ "Long", "Hoang Ngoc", "" ] ]
The mass spectrum and the eigenstates of the Higgs sector of the minimal 3 3 1 model are revisited in detail. There are discrepancies between our results and previous results by another author.
0710.3818
Marina-Aura Dariescu
Marina--Aura Dariescu and Ciprian Dariescu
Improved Factorization Method in Studying B-meson Decays
8 pgs, International Conference on Hadron Physics TROIA'07, Canakkale, Turkey, 30 August - 03 September 2007
null
null
null
hep-ph
null
B decays are a subject of active research since they provide useful information on the dynamics of strong and electroweak interactions for testing the Standard Model (SM) and models beyond and are ideally suited for a critical analysis of CP violation phenomena. Within the standard model, there exist certain relations between CP violating rate differences in B decays in the SU(3) limit, as for example $\Delta (\bar{B}^0 \to \pi^+ \pi^-) = - \Delta (\bar{B}^0 \to \pi^+ K^-)$. The goal of this letter is to study the direct CP violation asymmetry in a class of processes where there has been recent theoretical progress, as for example the B decays into two light pseudoscalars mesons and into a light pseudoscalar and a light vector meson. We identify relations between rate asymmetries which are valid in the SU(3) limit in the standard model and we compute SU(3) breaking corrections to them, going beyond the naive factorization by using the QCD improved factorization model of Beneke {\it et al.}. Finally, in some processes as for example $BR(B^- \to \eta^{\prime} K^-)$, we claim that one has to add SUSY contributions to the Wilson coefficients. In these cases, we end with a $BR$ depending on three parameters, whose values are constrained by the experimental data.
[ { "created": "Sat, 20 Oct 2007 05:34:59 GMT", "version": "v1" } ]
2007-10-23
[ [ "Dariescu", "Marina--Aura", "" ], [ "Dariescu", "Ciprian", "" ] ]
B decays are a subject of active research since they provide useful information on the dynamics of strong and electroweak interactions for testing the Standard Model (SM) and models beyond and are ideally suited for a critical analysis of CP violation phenomena. Within the standard model, there exist certain relations between CP violating rate differences in B decays in the SU(3) limit, as for example $\Delta (\bar{B}^0 \to \pi^+ \pi^-) = - \Delta (\bar{B}^0 \to \pi^+ K^-)$. The goal of this letter is to study the direct CP violation asymmetry in a class of processes where there has been recent theoretical progress, as for example the B decays into two light pseudoscalars mesons and into a light pseudoscalar and a light vector meson. We identify relations between rate asymmetries which are valid in the SU(3) limit in the standard model and we compute SU(3) breaking corrections to them, going beyond the naive factorization by using the QCD improved factorization model of Beneke {\it et al.}. Finally, in some processes as for example $BR(B^- \to \eta^{\prime} K^-)$, we claim that one has to add SUSY contributions to the Wilson coefficients. In these cases, we end with a $BR$ depending on three parameters, whose values are constrained by the experimental data.
1612.07248
Antonio Vairo
Nora Brambilla, Miguel A. Escobedo, Joan Soto, Antonio Vairo
Quarkonium suppression in heavy-ion collisions: an open quantum system approach
6 pages, 3 figures
Phys. Rev. D 96, 034021 (2017)
10.1103/PhysRevD.96.034021
ICCUB-16-044, TUM-EFT 55/14
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad equation itself depend on only two non-perturbative parameters: the heavy-quark momentum diffusion coefficient and its dispersive counterpart. Finally, by numerically solving the Lindblad equation, we provide results for the $\Upsilon(1S)$ and $\Upsilon(2S)$ suppression.
[ { "created": "Wed, 21 Dec 2016 17:37:17 GMT", "version": "v1" } ]
2017-08-30
[ [ "Brambilla", "Nora", "" ], [ "Escobedo", "Miguel A.", "" ], [ "Soto", "Joan", "" ], [ "Vairo", "Antonio", "" ] ]
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad equation itself depend on only two non-perturbative parameters: the heavy-quark momentum diffusion coefficient and its dispersive counterpart. Finally, by numerically solving the Lindblad equation, we provide results for the $\Upsilon(1S)$ and $\Upsilon(2S)$ suppression.
hep-ph/0610420
Mohammad Hussein Yousif
M Y Hussein
Electromagetic proton form factors
7 pages, 1 figurs
null
null
null
hep-ph
null
The electromagnetic form factors are crucial to our understanding of the proton internal structure, and thus provide a strong constraint of the distributions of the charge and magnetization current within the proton. We adopted the quark-parton model for calculating and understanding the charge structure of the proton interms of the electromagnetic form factors. A remarkable agreement with the available experimental evidence is found.
[ { "created": "Tue, 31 Oct 2006 05:20:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hussein", "M Y", "" ] ]
The electromagnetic form factors are crucial to our understanding of the proton internal structure, and thus provide a strong constraint of the distributions of the charge and magnetization current within the proton. We adopted the quark-parton model for calculating and understanding the charge structure of the proton interms of the electromagnetic form factors. A remarkable agreement with the available experimental evidence is found.
2109.05682
Prasenjit Sanyal
Tanmoy Mondal and Prasenjit Sanyal
Same sign trilepton as signature of charged Higgs in two Higgs doublet model
19 pages, 6 figures, 3 tables
JHEP05(2022)040
10.1007/JHEP05(2022)040
KIAS-P21032, APCTP Pre2021-021
hep-ph
http://creativecommons.org/licenses/by/4.0/
We explored the prospect of looking for a fermiophobic charged Higgs ($\hpm$) via the same sign trilepton signal at the LHC. A fermiophobic scenario appears in the type-I two Higgs doublet model where the coupling of the $\hpm$ with the Standard Model fermions is inversely proportional to $\tb$. Almost all the experimental searches rely on the fermionic production and decay of the charged Higgs. Consequently, the limit on $\hpm$ for fermiophobic scenarios is non-existent unless $\tb$ is small. We show that for a fermiophobic case, the electroweak production of $\hpm$ is dominant for most of the parameter space. Subsequent bosonic decay of the charged and neutral Higgses give rise to the same sign trilepton signal. With a thorough phenomenological analysis, we demonstrate that the same sign trilepton signal can be an excellent complementary search to explore the high $\tb$ regions.
[ { "created": "Mon, 13 Sep 2021 03:21:07 GMT", "version": "v1" }, { "created": "Fri, 17 Sep 2021 06:39:42 GMT", "version": "v2" }, { "created": "Thu, 10 Mar 2022 13:00:55 GMT", "version": "v3" }, { "created": "Wed, 6 Apr 2022 06:06:04 GMT", "version": "v4" } ]
2022-05-11
[ [ "Mondal", "Tanmoy", "" ], [ "Sanyal", "Prasenjit", "" ] ]
We explored the prospect of looking for a fermiophobic charged Higgs ($\hpm$) via the same sign trilepton signal at the LHC. A fermiophobic scenario appears in the type-I two Higgs doublet model where the coupling of the $\hpm$ with the Standard Model fermions is inversely proportional to $\tb$. Almost all the experimental searches rely on the fermionic production and decay of the charged Higgs. Consequently, the limit on $\hpm$ for fermiophobic scenarios is non-existent unless $\tb$ is small. We show that for a fermiophobic case, the electroweak production of $\hpm$ is dominant for most of the parameter space. Subsequent bosonic decay of the charged and neutral Higgses give rise to the same sign trilepton signal. With a thorough phenomenological analysis, we demonstrate that the same sign trilepton signal can be an excellent complementary search to explore the high $\tb$ regions.
0710.5027
Thomas Schwetz
Thomas Schwetz
Neutrino oscillations: present status and outlook
6 pages, 5 figures, plenary talk at NuFact07, Okayama, Japan
AIPConf.Proc.981:8-12,2008
10.1063/1.2899010
CERN-PH-TH-207
hep-ph
null
I summarize the status of three-flavour neutrino oscillations with date of Oct. 2007, and provide an outlook for the developments to be expected in the near future. Furthermore, I discuss the status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results, and comment on implications for the future neutrino oscillation program.
[ { "created": "Fri, 26 Oct 2007 08:52:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Schwetz", "Thomas", "" ] ]
I summarize the status of three-flavour neutrino oscillations with date of Oct. 2007, and provide an outlook for the developments to be expected in the near future. Furthermore, I discuss the status of sterile neutrino oscillation interpretations of the LSND anomaly in the light of recent MiniBooNE results, and comment on implications for the future neutrino oscillation program.
1910.11746
Felix Ringer
Tom Kaufmann, Xiaohui Liu, Asmita Mukherjee, Felix Ringer, Werner Vogelsang
Hadron-in-jet production at partonic threshold
22 pages, 4 figures
null
10.1007/JHEP02(2020)040
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the longitudinal momentum distribution of hadrons inside jets in proton-proton collisions. At partonic threshold large double logarithmic corrections arise which need to be resummed to all orders. We develop a factorization formalism within SCET that allows for the joint resummation of threshold and jet radius logarithms. We achieve next-to-leading logarithmic NLL$'$ accuracy by including non-global logarithms in the leading-color approximation. Overall, we find that the threshold resummation leads to a sizable enhancement of the cross section and a reduced QCD scale dependence, suggesting that the all-order resummation can be important for the reliable extraction of fragmentation functions in global analyses when jet substructure data is included.
[ { "created": "Fri, 25 Oct 2019 14:15:14 GMT", "version": "v1" } ]
2020-03-18
[ [ "Kaufmann", "Tom", "" ], [ "Liu", "Xiaohui", "" ], [ "Mukherjee", "Asmita", "" ], [ "Ringer", "Felix", "" ], [ "Vogelsang", "Werner", "" ] ]
We consider the longitudinal momentum distribution of hadrons inside jets in proton-proton collisions. At partonic threshold large double logarithmic corrections arise which need to be resummed to all orders. We develop a factorization formalism within SCET that allows for the joint resummation of threshold and jet radius logarithms. We achieve next-to-leading logarithmic NLL$'$ accuracy by including non-global logarithms in the leading-color approximation. Overall, we find that the threshold resummation leads to a sizable enhancement of the cross section and a reduced QCD scale dependence, suggesting that the all-order resummation can be important for the reliable extraction of fragmentation functions in global analyses when jet substructure data is included.
hep-ph/0507307
Jogesh C. Pati
Jogesh C. Pati
A Unified Picture with Neutrino As a Central Feature
46 pages
Proceedings of the XI International Workshop on `` Neutrino Telescopes'', Venice, February 21-25, 2005
null
null
hep-ph
null
In the first part of this talk it is discussed why observed neutrino oscillations (which suggest the existence of right-handed neutrinos with certain Dirac and Majorana masses) seem to select out the route to higher unification based on the symmetry SU(4)-color. This in turn selects out the effective symmetry in 4D near the GUT/string scale to be either SO(10) or minimally G(224)= SU(2)_L\times SU(2)_R \times SU(4)^c. The same conclusion is reached by the likely need for leptogenesis as the means for baryogenesis and also by the success of certain fermion mass-relations including m_b(M_{GUT})\approx m_\tau, together with m(\nu^\tau)_{Dirac}\approx m_{top}(M_{GUT}). In the second part, an attempt is made to provide a unified picture of a set of diverse phenomena based on an effective G(224) symmetry or SO(10), possessing supersymmetry. The phenomena in question include: (a) fermion masses and mixings, (b) neutrino oscillations, (c) CP non-conservation, (d) flavor violations in quark and lepton sectors, as well as (e) baryogenesis via leptogenesis. Including SM and SUSY contributions, the latter being sub-dominant, the framework correctly accounts for \Delta m_K, \Delta m_{B_d}, S(B_d -> J/\psi K_s) and \epsilon_K, and predicts S(B_d-> \phi K_s) to be in the range +(0.65-0.73), close to the SM-prediction. It also quite plausibly accounts for the observed baryon excess Y_B\approx 10^{-10}. Furthermore the model predicts enhanced rates for mu -> e gamma, tau-> mu gamma and mu N-> e N and also measurable electric dipole moment for the neutron. Expectations arising within the same framework for proton decay are summarized at the end. It is stressed that the potential for discovering proton decay in a megaton-size detector would be high.
[ { "created": "Tue, 26 Jul 2005 22:18:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pati", "Jogesh C.", "" ] ]
In the first part of this talk it is discussed why observed neutrino oscillations (which suggest the existence of right-handed neutrinos with certain Dirac and Majorana masses) seem to select out the route to higher unification based on the symmetry SU(4)-color. This in turn selects out the effective symmetry in 4D near the GUT/string scale to be either SO(10) or minimally G(224)= SU(2)_L\times SU(2)_R \times SU(4)^c. The same conclusion is reached by the likely need for leptogenesis as the means for baryogenesis and also by the success of certain fermion mass-relations including m_b(M_{GUT})\approx m_\tau, together with m(\nu^\tau)_{Dirac}\approx m_{top}(M_{GUT}). In the second part, an attempt is made to provide a unified picture of a set of diverse phenomena based on an effective G(224) symmetry or SO(10), possessing supersymmetry. The phenomena in question include: (a) fermion masses and mixings, (b) neutrino oscillations, (c) CP non-conservation, (d) flavor violations in quark and lepton sectors, as well as (e) baryogenesis via leptogenesis. Including SM and SUSY contributions, the latter being sub-dominant, the framework correctly accounts for \Delta m_K, \Delta m_{B_d}, S(B_d -> J/\psi K_s) and \epsilon_K, and predicts S(B_d-> \phi K_s) to be in the range +(0.65-0.73), close to the SM-prediction. It also quite plausibly accounts for the observed baryon excess Y_B\approx 10^{-10}. Furthermore the model predicts enhanced rates for mu -> e gamma, tau-> mu gamma and mu N-> e N and also measurable electric dipole moment for the neutron. Expectations arising within the same framework for proton decay are summarized at the end. It is stressed that the potential for discovering proton decay in a megaton-size detector would be high.
0904.3773
Bhaskar Dutta
Bhaskar Dutta, Louis Leblond and Kuver Sinha
Mirage in the Sky: Non-thermal Dark Matter, Gravitino Problem, and Cosmic Ray Anomalies
11 pages, 4 figures
Phys.Rev.D80:035014,2009
10.1103/PhysRevD.80.035014
MIFP-09-19, NSF-KITP-09-52
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent anomalies in cosmic rays could be due to dark matter annihilation in our galaxy. In order to get the required large cross-section to explain the data while still obtaining the right relic density, we rely on a non standard thermal history between dark matter freeze-out and Big-Bang Nucleosynthesis (BBN). We show that through a reheating phase from the decay of a heavy moduli or even the gravitino, we can produce the right relic density of dark matter if its self-annihilation cross-section is large enough. In addition to fitting the recent data, this scenario solves the cosmological moduli and gravitino problems. We illustrate this mechanism with a specific example in the context of U(1)_{B-L} extended MSSM where supersymmetry is broken via mirage mediation. These string motivated models naturally contain heavy moduli decaying to the gravitino, whose subsequent decay to the LSP can reheat the universe at a low temperature. The right-handed sneutrino and the B-L gaugino can both be viable dark matter candidates with large cross-section. They are leptophilic because of B-L charges. We also show that it is possible to distinguish the non-thermal from the thermal scenario (using Sommerfeld enhancement) in direct detection experiments for certain regions of parameter space.
[ { "created": "Fri, 24 Apr 2009 01:23:44 GMT", "version": "v1" } ]
2009-09-02
[ [ "Dutta", "Bhaskar", "" ], [ "Leblond", "Louis", "" ], [ "Sinha", "Kuver", "" ] ]
Recent anomalies in cosmic rays could be due to dark matter annihilation in our galaxy. In order to get the required large cross-section to explain the data while still obtaining the right relic density, we rely on a non standard thermal history between dark matter freeze-out and Big-Bang Nucleosynthesis (BBN). We show that through a reheating phase from the decay of a heavy moduli or even the gravitino, we can produce the right relic density of dark matter if its self-annihilation cross-section is large enough. In addition to fitting the recent data, this scenario solves the cosmological moduli and gravitino problems. We illustrate this mechanism with a specific example in the context of U(1)_{B-L} extended MSSM where supersymmetry is broken via mirage mediation. These string motivated models naturally contain heavy moduli decaying to the gravitino, whose subsequent decay to the LSP can reheat the universe at a low temperature. The right-handed sneutrino and the B-L gaugino can both be viable dark matter candidates with large cross-section. They are leptophilic because of B-L charges. We also show that it is possible to distinguish the non-thermal from the thermal scenario (using Sommerfeld enhancement) in direct detection experiments for certain regions of parameter space.
hep-ph/9704394
Igor Shovkovy
V.P. Gusynin and I.A. Shovkovy
Chiral Symmetry Breaking in QED in a Magnetic Field at Finite Temperature
9 pages. REVTeX
Phys.Rev. D56 (1997) 5251-5253
10.1103/PhysRevD.56.5251
Kiev preprint ITP-97-23E
hep-ph hep-th
null
The catalysis of chiral symmetry breaking in the massless weakly coupled QED in a magnetic field at finite temperature is studied. The temperature of the symmetry restoration is estimated analytically as $T_c\simeq m_{dyn}$, where $m_{dyn}$ is the dynamical mass of a fermion at zero temperature.
[ { "created": "Thu, 24 Apr 1997 13:58:12 GMT", "version": "v1" } ]
2016-09-06
[ [ "Gusynin", "V. P.", "" ], [ "Shovkovy", "I. A.", "" ] ]
The catalysis of chiral symmetry breaking in the massless weakly coupled QED in a magnetic field at finite temperature is studied. The temperature of the symmetry restoration is estimated analytically as $T_c\simeq m_{dyn}$, where $m_{dyn}$ is the dynamical mass of a fermion at zero temperature.
hep-ph/0112011
Ladisa Massimo
G. Eilam, M. Ladisa, Y.D. Yang (Technion)
Semileptonic and nonleptonic B decays to three charm quarks: B->J/psi (eta_c) D l nu and J/psi (eta_c) D pi
14 pages, 4 figures
Phys.Rev. D67 (2003) 054022
10.1103/PhysRevD.67.054022
null
hep-ph
null
We evaluate the form factors describing the semileptonic decays $\bar{B^0}\to J/\psi (\eta_c) D^+ \ell^- \bar \nu_\ell$, within the framework of a QCD relativistic potential model. This decay is complementary to $\bar{B^0}\to J/\psi (\eta_c) D^+ \pi^-$ in a phase space region where a pion factors out.We estimate the branching ratio for these semileptonic and nonleptonic channels, finding $\mathcal{BR}(\bar{B^0} \to J/\psi (\eta_c) D^+ \ell \nu_\ell) \simeq 10^{-13}$, $\mathcal{BR}(\bar{B^0} \to J/\psi D^+ \pi^-) = 3.1 \times 10^{-8}$ and $\mathcal{BR}(\bar{B^0} \to \eta_c D^+ \pi^-) = 3.5 \times 10^{-8}$.
[ { "created": "Sun, 2 Dec 2001 13:49:18 GMT", "version": "v1" } ]
2009-11-07
[ [ "Eilam", "G.", "", "Technion" ], [ "Ladisa", "M.", "", "Technion" ], [ "Yang", "Y. D.", "", "Technion" ] ]
We evaluate the form factors describing the semileptonic decays $\bar{B^0}\to J/\psi (\eta_c) D^+ \ell^- \bar \nu_\ell$, within the framework of a QCD relativistic potential model. This decay is complementary to $\bar{B^0}\to J/\psi (\eta_c) D^+ \pi^-$ in a phase space region where a pion factors out.We estimate the branching ratio for these semileptonic and nonleptonic channels, finding $\mathcal{BR}(\bar{B^0} \to J/\psi (\eta_c) D^+ \ell \nu_\ell) \simeq 10^{-13}$, $\mathcal{BR}(\bar{B^0} \to J/\psi D^+ \pi^-) = 3.1 \times 10^{-8}$ and $\mathcal{BR}(\bar{B^0} \to \eta_c D^+ \pi^-) = 3.5 \times 10^{-8}$.
hep-ph/0210401
Margarete Muhlleitner
Margarete Muhlleitner
MSSM Higgs particles in the intense--coupling regime
Talk given at the 10th International Conference on Supersymmetry and Unfication of Fundamental Interactions (SUSY02), Hamburg, Germany, 17-23 Jun 2002; 7 pp
null
null
PM/02-40, PSI-PR-02-16
hep-ph
null
In the "intense--coupling" regime all Higgs bosons of the Minimal Supersymmetric extension of the Standard Model (MSSM) are rather light and have comparable masses of O(100 GeV). They couple maximally to electroweak gauge bosons, and for large ratios of the vacuum expectation values of the two Higgs doublet fields, tan\beta, they interact strongly with the standard third generation fermions. We present in this note a comprehensive study of this scenario. We summarize the main phenomenological features, and the accordance with the direct constraints from Higgs boson searches at LEP2 and the Tevatron as well as the indirect constraints from precision measurements will be checked. After the presentation of the decay branching ratios, we discuss the production cross sections of the neutral Higgs particles in this regime at future colliders, the Tevatron Run II, the LHC and a 500 GeV e+e- linear collider.
[ { "created": "Tue, 29 Oct 2002 11:51:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Muhlleitner", "Margarete", "" ] ]
In the "intense--coupling" regime all Higgs bosons of the Minimal Supersymmetric extension of the Standard Model (MSSM) are rather light and have comparable masses of O(100 GeV). They couple maximally to electroweak gauge bosons, and for large ratios of the vacuum expectation values of the two Higgs doublet fields, tan\beta, they interact strongly with the standard third generation fermions. We present in this note a comprehensive study of this scenario. We summarize the main phenomenological features, and the accordance with the direct constraints from Higgs boson searches at LEP2 and the Tevatron as well as the indirect constraints from precision measurements will be checked. After the presentation of the decay branching ratios, we discuss the production cross sections of the neutral Higgs particles in this regime at future colliders, the Tevatron Run II, the LHC and a 500 GeV e+e- linear collider.
hep-ph/0206033
Todd Fugleberg
Todd. D. Fugleberg (BNL)
General Quasiparticle Propagator and Mass Dependence in Degenerate Color Superconductivity
35 pages, 10 figures, LaTeX; Reference and related comments added
Phys.Rev. D67 (2003) 034013
10.1103/PhysRevD.67.034013
null
hep-ph
null
The general quasiparticle propagator in dense quark matter is derived for equal mass quarks. Specialized to an NJL model, this propagator includes one new condensate, $\Delta_3$, in addition to the usual CFL condensate, $\Delta_1$. The gap equation is solved in two NJL models and the dependence on the quark mass of the condensates and the gap is presented. Analytic approximations for the condensates are obtained and compared to exact numerical solutions. The results are shown to differ from those obtained by neglecting $\Delta_3$, especially for smaller values of $\Delta_1$. The two different NJL models presented are also shown to give different results when $\Delta_3$ is not neglected. The methods used in this paper can be generalized to the physical case where only the strange quark is significantly massive.
[ { "created": "Tue, 4 Jun 2002 16:10:37 GMT", "version": "v1" }, { "created": "Fri, 23 Aug 2002 18:43:23 GMT", "version": "v2" } ]
2009-11-07
[ [ "Fugleberg", "Todd. D.", "", "BNL" ] ]
The general quasiparticle propagator in dense quark matter is derived for equal mass quarks. Specialized to an NJL model, this propagator includes one new condensate, $\Delta_3$, in addition to the usual CFL condensate, $\Delta_1$. The gap equation is solved in two NJL models and the dependence on the quark mass of the condensates and the gap is presented. Analytic approximations for the condensates are obtained and compared to exact numerical solutions. The results are shown to differ from those obtained by neglecting $\Delta_3$, especially for smaller values of $\Delta_1$. The two different NJL models presented are also shown to give different results when $\Delta_3$ is not neglected. The methods used in this paper can be generalized to the physical case where only the strange quark is significantly massive.
hep-ph/0701216
Robert Fleischer
Robert Fleischer (CERN)
Theoretical Review of $\gamma/\phi_3$ Measurements with $B_s$ Decays to Charm
4 pages, 2 figures, talk given at the 4th International Workshop on the CKM Unitarity Triangle (CKM2006), 12-16 December 2006, Nagoya, Japan, to appear in the proceedings (KEK Report)
null
null
CERN-PH-TH/2007-016
hep-ph
null
We give an overview of various determinations of $\gamma/\phi_3$ with the help of $B_s$ decays into charmed final states, distinguishing between transitions with tree and penguin contributions and pure tree decays. In the corresponding strategies, the $U$-spin flavour symmetry of strong interactions provides a very useful tool, and offers interesting "by-producs" for the $B$-physics programme at the LHC, including the control of the penguin uncertainties in the determinations of the $B^0_d$-$\bar B^0_d$ and $B^0_s$--$\bar B^0_s$ mixing phases $\phi_d$ and $\phi_s$ from $B_d\to J/\psi K_S$ and $B_s\to J/\psi\phi$, respectively, and an alternative extraction of the latter phase through $B_s\to D_s^+D_s^-$. Finally, we point out that the cleanest determinations of the mixing phases $\phi_s$ and $\phi_d$ are offered by the pure tree decays $B_s\to D_\pm K_{S(L)}$ and $B_d\to D_\pm\pi^0, D_\pm\rho^0, ...$, respectively, which are very interesting for the searches of new physics.
[ { "created": "Thu, 25 Jan 2007 15:33:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fleischer", "Robert", "", "CERN" ] ]
We give an overview of various determinations of $\gamma/\phi_3$ with the help of $B_s$ decays into charmed final states, distinguishing between transitions with tree and penguin contributions and pure tree decays. In the corresponding strategies, the $U$-spin flavour symmetry of strong interactions provides a very useful tool, and offers interesting "by-producs" for the $B$-physics programme at the LHC, including the control of the penguin uncertainties in the determinations of the $B^0_d$-$\bar B^0_d$ and $B^0_s$--$\bar B^0_s$ mixing phases $\phi_d$ and $\phi_s$ from $B_d\to J/\psi K_S$ and $B_s\to J/\psi\phi$, respectively, and an alternative extraction of the latter phase through $B_s\to D_s^+D_s^-$. Finally, we point out that the cleanest determinations of the mixing phases $\phi_s$ and $\phi_d$ are offered by the pure tree decays $B_s\to D_\pm K_{S(L)}$ and $B_d\to D_\pm\pi^0, D_\pm\rho^0, ...$, respectively, which are very interesting for the searches of new physics.
hep-ph/0412333
Colin David Froggatt
C.D. Froggatt, L.V. Laperashvili, R.B. Nevzorov, H.B. Nielsen, M. Sher
The Two Higgs Doublet Model and the Multiple Point Principle
14 pages, 2 figures, to be published in the Proceedings of the Bled workshop on What comes beyond the Standard Model?, 19-30 July 2004
null
null
GUTPA/04/12/01
hep-ph
null
According to the multiple point principle, Nature adjusts coupling parameters so that many vacuum states exist and each has approximately zero vacuum energy density. We apply this principle to the general two-Higgs doublet extension of the Standard Model, by requiring the existence of a large set of degenerate vacua at an energy scale much higher than the presently realized electroweak scale vacuum. It turns out that two scenarios are allowed. In the first scenario, a CP conserving Higgs potential and the absence of flavour changing neutral currents are obtained without fine-tuning. In the second scenario, the photon becomes massive in the high scale vacua. We briefly discuss the resulting phenomenology.
[ { "created": "Wed, 22 Dec 2004 13:00:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Froggatt", "C. D.", "" ], [ "Laperashvili", "L. V.", "" ], [ "Nevzorov", "R. B.", "" ], [ "Nielsen", "H. B.", "" ], [ "Sher", "M.", "" ] ]
According to the multiple point principle, Nature adjusts coupling parameters so that many vacuum states exist and each has approximately zero vacuum energy density. We apply this principle to the general two-Higgs doublet extension of the Standard Model, by requiring the existence of a large set of degenerate vacua at an energy scale much higher than the presently realized electroweak scale vacuum. It turns out that two scenarios are allowed. In the first scenario, a CP conserving Higgs potential and the absence of flavour changing neutral currents are obtained without fine-tuning. In the second scenario, the photon becomes massive in the high scale vacua. We briefly discuss the resulting phenomenology.
0908.2003
Zhi-Gang Wang
Zhi-Gang Wang, Xiao-Hong Zhang
Analysis of the pseudoscalar partner of the Y(4660) and related bound states
16 pages, 28 figures, revised version
Eur.Phys.J.C66:419-428,2010
10.1140/epjc/s10052-010-1253-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we study the pseudoscalar bound state $\eta_c'f_0(980)$ (irrespective of the hadro-charmonium and the molecular state) with the QCD sum rules. Considering the SU(3) symmetry of the light flavor quarks and the heavy quark symmetry, we also study the bound states $\eta_c'\sigma(400-1200)$, $\eta_b'''f_0(980)$ and $\eta_b'''\sigma(400-1200)$, and make reasonable predictions for their masses.
[ { "created": "Fri, 14 Aug 2009 01:18:11 GMT", "version": "v1" }, { "created": "Fri, 30 Oct 2009 02:30:18 GMT", "version": "v2" }, { "created": "Fri, 1 Jan 2010 07:25:37 GMT", "version": "v3" } ]
2010-04-26
[ [ "Wang", "Zhi-Gang", "" ], [ "Zhang", "Xiao-Hong", "" ] ]
In this article, we study the pseudoscalar bound state $\eta_c'f_0(980)$ (irrespective of the hadro-charmonium and the molecular state) with the QCD sum rules. Considering the SU(3) symmetry of the light flavor quarks and the heavy quark symmetry, we also study the bound states $\eta_c'\sigma(400-1200)$, $\eta_b'''f_0(980)$ and $\eta_b'''\sigma(400-1200)$, and make reasonable predictions for their masses.
hep-ph/0504202
Javier Redondo
Eduard Masso and Javier Redondo
Evading Astrophysical Constraints on Axion-Like Particles
Final Version Accepted in JCAP
JCAP0509:015,2005
10.1088/1475-7516/2005/09/015
UAB-FT-579
hep-ph astro-ph
null
Stellar energy loss arguments lead to strong constraints on the coupling $\phi \gamma \gamma$ of a light axion-like particle to two photons. Helioscopes, like CAST, are able to put competitive bounds. The PVLAS experiment has recently observed a rotation of the polarization of a laser propagating in a magnetic field that can be interpreted as the effect of a quite strong $\phi \gamma \gamma$ coupling. We present scenarios where the astrophysical and CAST bounds can be evaded, and we show that the PVLAS result can be accomodated in one of the models, provided the new physics scale is at very low energies.
[ { "created": "Fri, 22 Apr 2005 09:06:46 GMT", "version": "v1" }, { "created": "Tue, 31 May 2005 15:42:35 GMT", "version": "v2" }, { "created": "Fri, 9 Sep 2005 14:44:41 GMT", "version": "v3" } ]
2008-11-26
[ [ "Masso", "Eduard", "" ], [ "Redondo", "Javier", "" ] ]
Stellar energy loss arguments lead to strong constraints on the coupling $\phi \gamma \gamma$ of a light axion-like particle to two photons. Helioscopes, like CAST, are able to put competitive bounds. The PVLAS experiment has recently observed a rotation of the polarization of a laser propagating in a magnetic field that can be interpreted as the effect of a quite strong $\phi \gamma \gamma$ coupling. We present scenarios where the astrophysical and CAST bounds can be evaded, and we show that the PVLAS result can be accomodated in one of the models, provided the new physics scale is at very low energies.
hep-ph/0307354
Shouhua Zhu
Chao-Shang Huang (ITP, CAS) and Shou-hua Zhu (Carleton Uni)
CP violation in $B \to \Phi K_S$ in a model III 2HDM
Minor changes, version to appear in PRD
Phys.Rev. D68 (2003) 114020
10.1103/PhysRevD.68.114020
null
hep-ph hep-ex
null
The mixing induced time dependent CP asymmetry, direct CP asymmetry, and branching ratio in $B \to \Phi K_S$ in a model III 2HDM are calculated, in particular, neutral Higgs boson contributions are included. It is shown that satisfying all the relevant experimental constraints, for time dependent CP asymmetry $S_{\phi K}$ the model III can agree with the present data, $S_{\phi k}=-0.39\pm 0.41$, within the $1\sigma$ error, and the direct CP asymmetry which is zero in SM can be about $ -8% \sim -20%$ in the reasonable regions of parameters.
[ { "created": "Tue, 29 Jul 2003 18:01:03 GMT", "version": "v1" }, { "created": "Mon, 11 Aug 2003 16:12:11 GMT", "version": "v2" }, { "created": "Mon, 29 Sep 2003 13:17:30 GMT", "version": "v3" }, { "created": "Mon, 17 Nov 2003 14:35:47 GMT", "version": "v4" } ]
2009-11-10
[ [ "Huang", "Chao-Shang", "", "ITP, CAS" ], [ "Zhu", "Shou-hua", "", "Carleton Uni" ] ]
The mixing induced time dependent CP asymmetry, direct CP asymmetry, and branching ratio in $B \to \Phi K_S$ in a model III 2HDM are calculated, in particular, neutral Higgs boson contributions are included. It is shown that satisfying all the relevant experimental constraints, for time dependent CP asymmetry $S_{\phi K}$ the model III can agree with the present data, $S_{\phi k}=-0.39\pm 0.41$, within the $1\sigma$ error, and the direct CP asymmetry which is zero in SM can be about $ -8% \sim -20%$ in the reasonable regions of parameters.
0812.3371
Fredrick Olness
Fredrick Olness, Ingo Schienbein
Heavy Quarks: Lessons Learned from HERA and Tevatron
11 pages, 9 figures, to appear in the proceedings of the Ringberg Workshop "New Trends in HERA Physics 2008"
null
10.1016/j.nuclphysbps.2009.03.112
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review some of the recent developments which have enabled the heavy quark mass to be incorporated into both the calculation of the hard-scattering cross section and the PDFs. We compare and contrast some of the schemes that have been used in recent global PDF analyses, and look at issues that arise when these calculations are extended to NNLO.
[ { "created": "Wed, 17 Dec 2008 18:59:38 GMT", "version": "v1" } ]
2015-05-13
[ [ "Olness", "Fredrick", "" ], [ "Schienbein", "Ingo", "" ] ]
We review some of the recent developments which have enabled the heavy quark mass to be incorporated into both the calculation of the hard-scattering cross section and the PDFs. We compare and contrast some of the schemes that have been used in recent global PDF analyses, and look at issues that arise when these calculations are extended to NNLO.
hep-ph/0312080
Andre Peshier
A. Peshier, B. Kampfer, G. Soff
The QCD equation of state and quark star properties
Invited talk given by A. Peshier at the NATO Advanced Research Workshop "Superdense QCD Matter and Compact Stars", 27 September - 4 October 2003, Yerivan, Armenia
null
null
null
hep-ph
null
We review our quasiparticle model for the thermodynamics of strongly interacting matter at high temperature, and its extrapolation to non-zero chemical potential. Some implications of the resulting soft equation of state of quark matter at low temperatures are pointed out.
[ { "created": "Fri, 5 Dec 2003 11:42:03 GMT", "version": "v1" } ]
2009-09-29
[ [ "Peshier", "A.", "" ], [ "Kampfer", "B.", "" ], [ "Soff", "G.", "" ] ]
We review our quasiparticle model for the thermodynamics of strongly interacting matter at high temperature, and its extrapolation to non-zero chemical potential. Some implications of the resulting soft equation of state of quark matter at low temperatures are pointed out.
hep-ph/9409283
null
J. Milana and S. Nussinov
Possible Tests for $b \rightarrow s g$ Penguins via Inclusive $K$ Distributions and Exclusive Processes
19 pages + 4 figures, UMPP \#94--033
Phys.Rev.D51:1192-1198,1995
10.1103/PhysRevD.51.1192
null
hep-ph
null
We discuss experimental signatures capable of nearly immediate study that would discern/constrain new physics manifested via enhanced gluonic penguin decays of the $b$.
[ { "created": "Mon, 12 Sep 1994 19:59:53 GMT", "version": "v1" } ]
2011-07-19
[ [ "Milana", "J.", "" ], [ "Nussinov", "S.", "" ] ]
We discuss experimental signatures capable of nearly immediate study that would discern/constrain new physics manifested via enhanced gluonic penguin decays of the $b$.
2202.10067
Masaki J.S. Yang
Masaki J. S. Yang
A formula by $LDL^{T}$ decomposition for the minimal type-I seesaw mechanism and conditions of $CP$ symmetry in an arbitrary basis
13 pages
null
null
STUPP-21-253
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, defining a formula by $LDL^{T}$ decomposition for the minimal type-I seesaw mechanism, we obtain conditions of $CP$ symmetry for the neutrino mass matrix $m$ in an arbitrary basis. The conditions are found to be ${\rm Re\,} (M_{22} a_{i} - M_{12} b_{i}) \, {\rm Im \,} ( M_{22} a_{j} - M_{12} b_{j}) = - \det M \, {\rm Re\,} b_{i} \, {\rm Im \,} b_{j}$ or $ = - \det M \, {\rm Im \,} b_{i} \, {\rm Re\,} b_{j}$ for the Yukawa matrix $Y_{ij} = (a_{j}, b_{j})$ and the right-handed neutrino mass matrix $M_{ij}$. In other words, the real or imaginary part of $b_{i}$ must be proportional to the real or imaginary part of the quantity $(M_{22} a_{i} - M_{12} b_{i})$.
[ { "created": "Mon, 21 Feb 2022 09:27:01 GMT", "version": "v1" }, { "created": "Wed, 20 Apr 2022 05:52:36 GMT", "version": "v2" } ]
2022-04-21
[ [ "Yang", "Masaki J. S.", "" ] ]
In this paper, defining a formula by $LDL^{T}$ decomposition for the minimal type-I seesaw mechanism, we obtain conditions of $CP$ symmetry for the neutrino mass matrix $m$ in an arbitrary basis. The conditions are found to be ${\rm Re\,} (M_{22} a_{i} - M_{12} b_{i}) \, {\rm Im \,} ( M_{22} a_{j} - M_{12} b_{j}) = - \det M \, {\rm Re\,} b_{i} \, {\rm Im \,} b_{j}$ or $ = - \det M \, {\rm Im \,} b_{i} \, {\rm Re\,} b_{j}$ for the Yukawa matrix $Y_{ij} = (a_{j}, b_{j})$ and the right-handed neutrino mass matrix $M_{ij}$. In other words, the real or imaginary part of $b_{i}$ must be proportional to the real or imaginary part of the quantity $(M_{22} a_{i} - M_{12} b_{i})$.
hep-ph/9910210
Hannes Jung
S.P. Baranov (Lebedev Institute, Moscow) H. Jung (Lund Univ.), N.P. Zotov (Moscow State University)
Charm production in the semi-hard approach of QCD and the unintegrated gluon distribution
Latex 8 pages, 4 pages
null
null
LUNFD6/(NFFL-7176) 1999
hep-ph
null
In the framework of semi-hard QCD approach, we present a consistent analysis of D^* meson production at HERA energies. The consideration is based on universal unintegrated gluon densities, which have BFKL behavior in the small x region. Predictions of the CCFM evolution equation for D^* production are obtained and show a good description of D^* data at HERA.
[ { "created": "Sat, 2 Oct 1999 08:45:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baranov", "S. P.", "", "Lebedev Institute, Moscow" ], [ "Jung", "H.", "", "Lund Univ." ], [ "Zotov", "N. P.", "", "Moscow State University" ] ]
In the framework of semi-hard QCD approach, we present a consistent analysis of D^* meson production at HERA energies. The consideration is based on universal unintegrated gluon densities, which have BFKL behavior in the small x region. Predictions of the CCFM evolution equation for D^* production are obtained and show a good description of D^* data at HERA.
hep-ph/9912244
Afsar Abbas
Afsar Abbas
Electric charge, early universe and the Superstring Theories
Latex file, 6 pages, no figures
null
null
null
hep-ph astro-ph
null
Very recently, it has been shown by the author that the Standard Model Higgs cannot be a physical particle. Here, on most general grounds it is established that as per the Standard Model there is no electric charge above the electro-weak phase transition temperature. Hence there was no electric charge present in the early universe. The Superstring Theories are flawed in as much as they are incompatible with this requirement. Hence the Superstring Theories are inconsistent with this basic structure and requirement of the Standard Model.
[ { "created": "Sun, 5 Dec 1999 13:52:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Abbas", "Afsar", "" ] ]
Very recently, it has been shown by the author that the Standard Model Higgs cannot be a physical particle. Here, on most general grounds it is established that as per the Standard Model there is no electric charge above the electro-weak phase transition temperature. Hence there was no electric charge present in the early universe. The Superstring Theories are flawed in as much as they are incompatible with this requirement. Hence the Superstring Theories are inconsistent with this basic structure and requirement of the Standard Model.
2009.07909
Michael Clark
Michael Clark, Amanda Depoian, Bahaa Elshimy, Abigail Kopec, Rafael F. Lang, Shengchao Li, Juehang Qin
Direct Detection Limits on Heavy Dark Matter
4 pages, 4 figures. Updated version, following the errata published in Phys. Rev. D 104, 129903
Phys. Rev. D 102, 123026 (2020), including erratum Phys. Rev. D 104, 129903
10.1103/PhysRevD.102.123026
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiply-interacting massive particles (MIMPs) are heavy (>10^10 GeV/c^2) dark matter particles that interact strongly with regular matter, but may have evaded detection due to the low number density required to make up the local dark matter halo. These particles could leave track-like signatures in current experiments, similar to lightly-ionizing particles. We show that previously calculated limits from the MAJORANA Demonstrator on the flux of lightly-ionizing particles can be used to exclude MIMP dark matter parameter space up to a mass of 10^15 GeV/c^2. We also calculate limits from the standard XENON1T analysis in this high-mass regime, properly taking into account flux limitations and multi-scatter effects. Finally, we show that a dedicated MIMP analysis using the XENON1T dark matter search could probe unexplored parameter space up to masses of 10^18 GeV/c^2.
[ { "created": "Wed, 16 Sep 2020 19:38:01 GMT", "version": "v1" }, { "created": "Thu, 31 Dec 2020 16:40:54 GMT", "version": "v2" }, { "created": "Mon, 10 Jan 2022 20:49:09 GMT", "version": "v3" } ]
2022-01-12
[ [ "Clark", "Michael", "" ], [ "Depoian", "Amanda", "" ], [ "Elshimy", "Bahaa", "" ], [ "Kopec", "Abigail", "" ], [ "Lang", "Rafael F.", "" ], [ "Li", "Shengchao", "" ], [ "Qin", "Juehang", "" ] ]
Multiply-interacting massive particles (MIMPs) are heavy (>10^10 GeV/c^2) dark matter particles that interact strongly with regular matter, but may have evaded detection due to the low number density required to make up the local dark matter halo. These particles could leave track-like signatures in current experiments, similar to lightly-ionizing particles. We show that previously calculated limits from the MAJORANA Demonstrator on the flux of lightly-ionizing particles can be used to exclude MIMP dark matter parameter space up to a mass of 10^15 GeV/c^2. We also calculate limits from the standard XENON1T analysis in this high-mass regime, properly taking into account flux limitations and multi-scatter effects. Finally, we show that a dedicated MIMP analysis using the XENON1T dark matter search could probe unexplored parameter space up to masses of 10^18 GeV/c^2.
hep-ph/0109173
Michael McNeil Forbes
Michael McNeil Forbes and Ariel R. Zhitnitsky
Global Strings in High Density QCD
LaTeX JHEP-format (26 pages) Option in source for REVTeX4 format
Phys.Rev. D65 (2002) 085009
10.1103/PhysRevD.65.085009
MIT-CTP-3190
hep-ph astro-ph hep-th nucl-th
null
We show that several types of global strings occur in colour superconducting quark matter due to the spontaneous violation of relevant U(1) symmetries. These include the baryon U(1)_B, and approximate axial U(1)_A symmetries as well as an approximate U(1)_S arising from kaon condensation. We discuss some general properties of these strings and their interactions. In particular, we demonstrate that the U(1)_A strings behave as superconducting strings. We draw some parallels between these strings and global cosmological strings and discuss some possible implications of these strings to the physics in neutron star cores.
[ { "created": "Wed, 19 Sep 2001 19:07:32 GMT", "version": "v1" } ]
2009-11-07
[ [ "Forbes", "Michael McNeil", "" ], [ "Zhitnitsky", "Ariel R.", "" ] ]
We show that several types of global strings occur in colour superconducting quark matter due to the spontaneous violation of relevant U(1) symmetries. These include the baryon U(1)_B, and approximate axial U(1)_A symmetries as well as an approximate U(1)_S arising from kaon condensation. We discuss some general properties of these strings and their interactions. In particular, we demonstrate that the U(1)_A strings behave as superconducting strings. We draw some parallels between these strings and global cosmological strings and discuss some possible implications of these strings to the physics in neutron star cores.
1404.5230
Xin Gao
Xin Gao, Tianjun Li, Pramod Shukla
Fractional chaotic inflation in the lights of PLANCK and BICEP2
16 pages, 5 figures, references added, published in PLB
Phys. Lett. B 738 (2014) 412-417
10.1016/j.physletb.2014.10.007
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the lights of current BICEP2 observations accompanied with the PLANCK satellite results, it has been observed that the simple single field chaotic inflationary models provide a good agreement with their spectral index n_s and large tensor-to-scalar ratio r (0.15 <r <0.26). To explore the other simple models, we consider the fractional-chaotic inflationary potentials of the form V_0 phi^(a/b) where a and b are relatively prime. We show that such kind of inflaton potentials can be realized elegantly in the supergravity framework with generalized shift symmetry and a nature bound a/b < 4 for consistency. Especially, for the number of e-folding from 50 to 60 and some a/b from 2 to 3, our predictions are nicely within at least 1 $\sigma$ region in the r-n_s plane. We also present a systematic investigation of such chaotic inflationary models with fractional exponents to explore the possibilities for the enhancement in the magnitude of running of spectral index (\alpha_{n_s}) beyond the simplistic models.
[ { "created": "Mon, 21 Apr 2014 16:01:35 GMT", "version": "v1" }, { "created": "Thu, 1 May 2014 15:46:48 GMT", "version": "v2" }, { "created": "Sun, 25 May 2014 15:52:43 GMT", "version": "v3" }, { "created": "Fri, 3 Oct 2014 21:51:58 GMT", "version": "v4" }, { "cre...
2014-10-20
[ [ "Gao", "Xin", "" ], [ "Li", "Tianjun", "" ], [ "Shukla", "Pramod", "" ] ]
In the lights of current BICEP2 observations accompanied with the PLANCK satellite results, it has been observed that the simple single field chaotic inflationary models provide a good agreement with their spectral index n_s and large tensor-to-scalar ratio r (0.15 <r <0.26). To explore the other simple models, we consider the fractional-chaotic inflationary potentials of the form V_0 phi^(a/b) where a and b are relatively prime. We show that such kind of inflaton potentials can be realized elegantly in the supergravity framework with generalized shift symmetry and a nature bound a/b < 4 for consistency. Especially, for the number of e-folding from 50 to 60 and some a/b from 2 to 3, our predictions are nicely within at least 1 $\sigma$ region in the r-n_s plane. We also present a systematic investigation of such chaotic inflationary models with fractional exponents to explore the possibilities for the enhancement in the magnitude of running of spectral index (\alpha_{n_s}) beyond the simplistic models.
1912.02106
Per Osland
A.A. Pankov, P. Osland, I.A. Serenkova and V.A. Bednyakov
High-precision limits on $W$-$W'$ and $Z$-$Z'$ mixing from diboson production using the full LHC Run 2 ATLAS data set
20 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1904.01432, arXiv:1809.08933. v2: clarifications, version published in EPJC
null
10.1140/epjc/s10052-020-8075-7
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The full ATLAS Run 2 data set with time-integrated luminosity of 139 fb$^{-1}$ in the diboson channels in hadronic final states is used to probe a simple model with an extended gauge sector (EGM), proposed by Altarelli et al., and often taken as a convenient benchmark by experimentalists. This model accommodates new charged $W'$ and neutral $Z'$ vector bosons with modified trilinear Standard Model gauge couplings, decaying into electroweak gauge boson pairs $WZ$ or $WW$, where $W$/$Z$ decay hadronically. Exclusion limits at the 95% C.L. on the $Z'$ and $W'$ resonance production cross section times branching ratio to electroweak gauge boson pairs in the mass range of $\sim$ 1 - 5 TeV are here converted to constraints on $W$-$W'$ and $Z$-$Z'$ mixing parameters and masses for the EGM. We present exclusion regions on the parameter space of the $W'$ and $Z'$ by using the full Run 2 data set comprised of $pp$ collisions at $\sqrt{s}=13$ TeV and recorded by the ATLAS detector at the CERN LHC. The obtained exclusion regions are significantly extended compared to those obtained from the previous analysis performed with Tevatron data as well as with LHC data collected at 7 and 8 TeV in Run 1 and are the most stringent bounds to date.
[ { "created": "Tue, 3 Dec 2019 06:34:15 GMT", "version": "v1" }, { "created": "Fri, 5 Jun 2020 15:39:53 GMT", "version": "v2" } ]
2020-07-15
[ [ "Pankov", "A. A.", "" ], [ "Osland", "P.", "" ], [ "Serenkova", "I. A.", "" ], [ "Bednyakov", "V. A.", "" ] ]
The full ATLAS Run 2 data set with time-integrated luminosity of 139 fb$^{-1}$ in the diboson channels in hadronic final states is used to probe a simple model with an extended gauge sector (EGM), proposed by Altarelli et al., and often taken as a convenient benchmark by experimentalists. This model accommodates new charged $W'$ and neutral $Z'$ vector bosons with modified trilinear Standard Model gauge couplings, decaying into electroweak gauge boson pairs $WZ$ or $WW$, where $W$/$Z$ decay hadronically. Exclusion limits at the 95% C.L. on the $Z'$ and $W'$ resonance production cross section times branching ratio to electroweak gauge boson pairs in the mass range of $\sim$ 1 - 5 TeV are here converted to constraints on $W$-$W'$ and $Z$-$Z'$ mixing parameters and masses for the EGM. We present exclusion regions on the parameter space of the $W'$ and $Z'$ by using the full Run 2 data set comprised of $pp$ collisions at $\sqrt{s}=13$ TeV and recorded by the ATLAS detector at the CERN LHC. The obtained exclusion regions are significantly extended compared to those obtained from the previous analysis performed with Tevatron data as well as with LHC data collected at 7 and 8 TeV in Run 1 and are the most stringent bounds to date.
1804.04919
Yicong Sui
Yicong Sui, P. S. Bhupal Dev
A Combined Astrophysical and Dark Matter Interpretation of the IceCube HESE and Throughgoing Muon Events
27 pages, 6 figures, 2 tables
null
10.1088/1475-7516/2018/07/020
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a combined likelihood analysis for the IceCube 6-year high-energy starting events (HESE) and 8-year throughgoing muon events above 10 TeV using a two-component neutrino flux model. The two-component flux can be motivated either from purely astrophysical sources or due to a beyond Standard Model contribution, such as decaying heavy dark matter. We find that the astrophysical plus dark matter interpretation is mildly preferred by the current data over the purely astrophysical explanation. As for the astrophysical neutrinos, we consider two different source flavor compositions corresponding to the standard pion decay and muon-damped pion decay sources. We find that the latter is slightly preferred over the former as the high-energy component, while the low-energy component does not show any such preference. We also take into account the multi-messenger gamma-ray constraints and find that our two-component fit is compatible with these constraints, whereas the single-component power-law bestfit to the HESE data is ruled out. The astrophysical plus dark matter interpretation of the two-component flux is found to be mildly preferred by the current data and the gamma-ray constraints over the purely astrophysical explanation.
[ { "created": "Fri, 13 Apr 2018 12:49:46 GMT", "version": "v1" }, { "created": "Thu, 5 Jul 2018 17:12:00 GMT", "version": "v2" } ]
2018-07-25
[ [ "Sui", "Yicong", "" ], [ "Dev", "P. S. Bhupal", "" ] ]
We perform a combined likelihood analysis for the IceCube 6-year high-energy starting events (HESE) and 8-year throughgoing muon events above 10 TeV using a two-component neutrino flux model. The two-component flux can be motivated either from purely astrophysical sources or due to a beyond Standard Model contribution, such as decaying heavy dark matter. We find that the astrophysical plus dark matter interpretation is mildly preferred by the current data over the purely astrophysical explanation. As for the astrophysical neutrinos, we consider two different source flavor compositions corresponding to the standard pion decay and muon-damped pion decay sources. We find that the latter is slightly preferred over the former as the high-energy component, while the low-energy component does not show any such preference. We also take into account the multi-messenger gamma-ray constraints and find that our two-component fit is compatible with these constraints, whereas the single-component power-law bestfit to the HESE data is ruled out. The astrophysical plus dark matter interpretation of the two-component flux is found to be mildly preferred by the current data and the gamma-ray constraints over the purely astrophysical explanation.
hep-ph/9312353
Paul F. Mende
Benjamin Grinstein and Paul F. Mende
Exact Heavy to Light Meson Form Factors in the Combined Heavy Quark, Large $N_c$ and Chiral Limits
12 pages (harvmac), Brown-HET-928
null
null
null
hep-ph
null
We demonstrate that the form factors of local operators between a heavy meson state (like the~$B$) and a light pseudoscalar state (like the pion) are given exactly by a single pole form in the combined heavy quark, large $N_c$ (number of colors) and chiral limits. We discuss the deviations from this exact result from finite heavy quark masses, non-zero light quark masses and finite $N_c$. We comment on some implications of this result.
[ { "created": "Thu, 30 Dec 1993 09:15:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grinstein", "Benjamin", "" ], [ "Mende", "Paul F.", "" ] ]
We demonstrate that the form factors of local operators between a heavy meson state (like the~$B$) and a light pseudoscalar state (like the pion) are given exactly by a single pole form in the combined heavy quark, large $N_c$ (number of colors) and chiral limits. We discuss the deviations from this exact result from finite heavy quark masses, non-zero light quark masses and finite $N_c$. We comment on some implications of this result.
0810.0588
Keisho Hidaka
K. Hidaka (Tokyo Gakugei Univ.)
Impact of slepton generation mixing on the search for sneutrinos
Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 4 pages, LaTeX, 3 eps figures, modified version with some minor changes specific to ICHEP08 Proceedings
null
null
TGU-37
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a systematic study of sneutrino production and decays in the Minimal Supersymmetric Standard Model (MSSM) with lepton flavour violation (LFV). We study bosonic decays of sneutrinos as well as fermionic ones. We show that the effect of slepton generation mixing on the sneutrino production and decays can be quite large in a significant part of the MSSM parameter space despite the very strong experimental limits on LFV processes. This could have an important impact on the search for sneutrinos and the determination of the MSSM parameters at LHC and future colliders, such as ILC, CLIC and muon collider.
[ { "created": "Fri, 3 Oct 2008 08:53:57 GMT", "version": "v1" }, { "created": "Sat, 24 Jan 2009 06:17:06 GMT", "version": "v2" } ]
2009-01-24
[ [ "Hidaka", "K.", "", "Tokyo Gakugei Univ." ] ]
We perform a systematic study of sneutrino production and decays in the Minimal Supersymmetric Standard Model (MSSM) with lepton flavour violation (LFV). We study bosonic decays of sneutrinos as well as fermionic ones. We show that the effect of slepton generation mixing on the sneutrino production and decays can be quite large in a significant part of the MSSM parameter space despite the very strong experimental limits on LFV processes. This could have an important impact on the search for sneutrinos and the determination of the MSSM parameters at LHC and future colliders, such as ILC, CLIC and muon collider.
hep-ph/0110291
Enrique Ruiz Arriola
R. M. Davidson (Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York) and E. Ruiz Arriola (Departamento de Fisica Moderna, Universidad de Granada, Spain.)
Parton Distributions Functions of Pion, Kaon and Eta pseudoscalar mesons in the NJL model
(Latex, epsfig) 17 pages, 7 figures
Acta Phys.Polon.B33:1791-1808,2002
null
UG/DFM-20 2001
hep-ph
null
Parton distributions of pseudoscalar pi,K and eta mesons obtained within the NJL model using the Pauli-Villars regularization method are analyzed in terms of LO and NLO evolution, and the valence sea quark and gluon parton distributions for the pion are obtained at Q^2 = 4 GeV^2 and compared to existing parametrizations at that scale. Surprisingly, the NLO order effects turn out to be small compared to the LO ones. The valence distributions are in good agreement with experimental analyses, but the gluon and sea distributions come out to be softer in the high-x region and harder in the low-x region than the experimental analyses suggest.
[ { "created": "Tue, 23 Oct 2001 08:08:31 GMT", "version": "v1" } ]
2014-11-17
[ [ "Davidson", "R. M.", "", "Department of Physics, Applied Physics and Astronomy,\n Rensselaer Polytechnic Institute, Troy, New York" ], [ "Arriola", "E. Ruiz", "", "Departamento de Fisica Moderna, Universidad de Granada, Spain." ] ]
Parton distributions of pseudoscalar pi,K and eta mesons obtained within the NJL model using the Pauli-Villars regularization method are analyzed in terms of LO and NLO evolution, and the valence sea quark and gluon parton distributions for the pion are obtained at Q^2 = 4 GeV^2 and compared to existing parametrizations at that scale. Surprisingly, the NLO order effects turn out to be small compared to the LO ones. The valence distributions are in good agreement with experimental analyses, but the gluon and sea distributions come out to be softer in the high-x region and harder in the low-x region than the experimental analyses suggest.
1201.1235
Marek G\'o\'zd\'z
M. G\'o\'zd\'z and W. A. Kami\'nski
Fermion-boson loops with bilinear R-parity violation leading to Majorana neutrino mass and magnetic moments
I've decided to move the collection of my papers to arXiv for easier access. Proceedings of the Nuclear Physics Workshop in Kazimierz Dolny, Poland, 2007
Int. J. Mod. Phys. E 17 (2008) 276
10.1142/S021830130800980X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present analytic expressions corresponding to a set of one loop Feynman diagrams, built within R-parity violating (RpV) minimal supersymmetric standard model (MSSM). Diagrams involve both bilinear and trilinear RpV couplings and represent Majorana neutrino masses and magnetic moments.
[ { "created": "Thu, 5 Jan 2012 17:59:52 GMT", "version": "v1" } ]
2015-06-03
[ [ "Góźdź", "M.", "" ], [ "Kamiński", "W. A.", "" ] ]
We present analytic expressions corresponding to a set of one loop Feynman diagrams, built within R-parity violating (RpV) minimal supersymmetric standard model (MSSM). Diagrams involve both bilinear and trilinear RpV couplings and represent Majorana neutrino masses and magnetic moments.
hep-ph/0512247
Felipe J. Llanes-Estrada
Stanley J. Brodsky (Stanford Linear Accelerator Center) and Felipe J. Llanes-Estrada (Univ. Complutense Madrid)
Renormalization Scale-Fixing for Complex Scattering Amplitudes
Second version, to be published in EPJC. several new comments and references
Eur.Phys.J.C46:751,2006
10.1140/epjc/s2006-02520-0
SLAC-PUB-11605
hep-ph
null
We show how to fix the renormalization scale for hard-scattering exclusive processes such as deeply virtual meson electroproduction by applying the BLM prescription to the imaginary part of the scattering amplitude and employing a fixed-t dispersion relation to obtain the scale-fixed real part. In this way we resolve the ambiguity in BLM renormalization scale-setting for complex scattering amplitudes. We illustrate this by computing the H generalized parton distribution at leading twist in an analytic quark-diquark model for the parton-proton scattering amplitude which can incorporate Regge exchange contributions characteristic of the deep inelastic structure functions.
[ { "created": "Tue, 20 Dec 2005 08:26:42 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2006 14:43:49 GMT", "version": "v2" } ]
2009-01-07
[ [ "Brodsky", "Stanley J.", "", "Stanford Linear Accelerator Center" ], [ "Llanes-Estrada", "Felipe J.", "", "Univ. Complutense Madrid" ] ]
We show how to fix the renormalization scale for hard-scattering exclusive processes such as deeply virtual meson electroproduction by applying the BLM prescription to the imaginary part of the scattering amplitude and employing a fixed-t dispersion relation to obtain the scale-fixed real part. In this way we resolve the ambiguity in BLM renormalization scale-setting for complex scattering amplitudes. We illustrate this by computing the H generalized parton distribution at leading twist in an analytic quark-diquark model for the parton-proton scattering amplitude which can incorporate Regge exchange contributions characteristic of the deep inelastic structure functions.
0908.3853
Ulrich Jentschura
U. D. Jentschura and V. G. Serbo
Nuclear form factor, validity of the equivalent photon approximation and Coulomb corrections to muon pair production in photon-nucleus and nucleus-nucleus collisions
9 pages, LaTeX
Eur.Phys.J.C64:309-317,2009
10.1140/epjc/s10052-009-1147-3
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study in detail the influence of the nuclear form factor both on the Born cross section and on the Coulomb corrections to the photo-production of muon pairs off heavy nuclei (gamma Z -> mu+ mu- Z$) and in heavy-ion collisions (ZZ -> ZZ mu+ mu-). Our findings indicate a number of issues which have not been sufficiently described as yet in the literature: (i) the use of a realistic form factor, based on the Fermi charge distribution for the nucleus, is absolutely indispensable for reliable theoretical predictions; (ii) we checked quantitatively that the equivalent photon approximation has a very good accuracy for the discussed processes; and (iii) we present a leading logarithmic calculation of the Coulomb corrections which correspond to multi-photon exchange of the produced mu+/- with the nuclei. These corrections are found to be small (on the percent level). Our result justifies using the Born approximation for numerical simulations of the discussed process at the RHIC and LHC colliders. Finally, we calculate the total cross section for muon pair production at RHIC and LHC.
[ { "created": "Wed, 26 Aug 2009 15:39:38 GMT", "version": "v1" } ]
2009-11-16
[ [ "Jentschura", "U. D.", "" ], [ "Serbo", "V. G.", "" ] ]
We study in detail the influence of the nuclear form factor both on the Born cross section and on the Coulomb corrections to the photo-production of muon pairs off heavy nuclei (gamma Z -> mu+ mu- Z$) and in heavy-ion collisions (ZZ -> ZZ mu+ mu-). Our findings indicate a number of issues which have not been sufficiently described as yet in the literature: (i) the use of a realistic form factor, based on the Fermi charge distribution for the nucleus, is absolutely indispensable for reliable theoretical predictions; (ii) we checked quantitatively that the equivalent photon approximation has a very good accuracy for the discussed processes; and (iii) we present a leading logarithmic calculation of the Coulomb corrections which correspond to multi-photon exchange of the produced mu+/- with the nuclei. These corrections are found to be small (on the percent level). Our result justifies using the Born approximation for numerical simulations of the discussed process at the RHIC and LHC colliders. Finally, we calculate the total cross section for muon pair production at RHIC and LHC.
hep-ph/0202183
Krutov A. F.
A.F. Krutov and V.E. Troitsky
Extraction of the neutron charge form factor from the charge form factor of deuteron
LaTeX2e, 12 pages, 2 figures, table
Eur.Phys.J.A16:285-290,2003
10.1140/epja/i2002-10077-9
null
hep-ph hep-ex nucl-ex nucl-th
null
We extract the neutron charge form factor from the charge form factor of deuteron obtained from $T_{20}(Q^2)$ data at $0\le Q^2\le$ 1.717 (GeV$^2$). The extraction is based on the relativistic impulse approximation in the instant form of the relativistic Hamiltonian dynamics. Our results (12 new points) are compatible with existing values of the neutron charge form factor of other authors. We propose a fit for the whole set (35 points) taking into account the data for the slope of the form factor at $Q^2 = 0$.
[ { "created": "Tue, 19 Feb 2002 11:59:46 GMT", "version": "v1" } ]
2011-08-17
[ [ "Krutov", "A. F.", "" ], [ "Troitsky", "V. E.", "" ] ]
We extract the neutron charge form factor from the charge form factor of deuteron obtained from $T_{20}(Q^2)$ data at $0\le Q^2\le$ 1.717 (GeV$^2$). The extraction is based on the relativistic impulse approximation in the instant form of the relativistic Hamiltonian dynamics. Our results (12 new points) are compatible with existing values of the neutron charge form factor of other authors. We propose a fit for the whole set (35 points) taking into account the data for the slope of the form factor at $Q^2 = 0$.
hep-ph/0002264
Martin Hirsch
M. Hirsch, J. C. Romao and J.W.F. Valle
Bilinear R-parity violating SUSY: Neutrinoless double beta decay in the light of solar and atmospheric neutrino data
1 reference added, enlarged discussion of loops
Phys.Lett.B486:255-262,2000
10.1016/S0370-2693(00)00781-4
FTUV/00-14 and IFIC/00-15
hep-ph
null
Neutrinoless double beta ($\znbb$) decay is considered within bilinear R-parity breaking supersymmetry, including the full one-loop corrections to the neutrino-neutralino mass matrix. Expected rates for $\znbb$ decay in this model are discussed in light of recent atmospheric and solar neutrino data. We conclude that (a) tree-level calculations for $\znbb$ decay within the bilinear model are not reliable in the range of parameters preferred by current solar and atmospheric neutrino problems. And (b) if the solar and atmospheric neutrino problems are to be solved within bilinear R-parity violating SUSY the expected rates for $\znbb$ decay are very low; the effective Majorana neutrino mass at most 0.01 eV and typical values being one order of magnitude lower. Observing $\znbb$ decay in the next round of experiments therefore would rule out the bilinear R-parity violating supersymmetric model as an explanation for solar and atmospheric neutrino oscillations, as well as any hierarchical scheme for neutrino masses, unless new neutrino interactions are present.
[ { "created": "Fri, 25 Feb 2000 11:19:51 GMT", "version": "v1" }, { "created": "Tue, 11 Apr 2000 17:17:17 GMT", "version": "v2" } ]
2009-09-17
[ [ "Hirsch", "M.", "" ], [ "Romao", "J. C.", "" ], [ "Valle", "J. W. F.", "" ] ]
Neutrinoless double beta ($\znbb$) decay is considered within bilinear R-parity breaking supersymmetry, including the full one-loop corrections to the neutrino-neutralino mass matrix. Expected rates for $\znbb$ decay in this model are discussed in light of recent atmospheric and solar neutrino data. We conclude that (a) tree-level calculations for $\znbb$ decay within the bilinear model are not reliable in the range of parameters preferred by current solar and atmospheric neutrino problems. And (b) if the solar and atmospheric neutrino problems are to be solved within bilinear R-parity violating SUSY the expected rates for $\znbb$ decay are very low; the effective Majorana neutrino mass at most 0.01 eV and typical values being one order of magnitude lower. Observing $\znbb$ decay in the next round of experiments therefore would rule out the bilinear R-parity violating supersymmetric model as an explanation for solar and atmospheric neutrino oscillations, as well as any hierarchical scheme for neutrino masses, unless new neutrino interactions are present.
1011.4574
Leonid Slad
L.M. Slad
Electromagnetic properties of non-Dirac particles with rest spin 1/2
18 pages, 2 figures
Theor.Math.Phys.165:1275-1292,2010
10.1007/s11232-010-0109-0
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We resolve a number of questions related to an analytic description of electromagnetic form factors of non-Dirac particles with the rest spin 1/2. We find the general structure of a matrix antisymmetric tensor operator. We obtain two recurrence relations for matrix elements of finite transformations of the proper Lorentz group and explicit formulas for a certain set of such elements. Within the theory of fields with double symmetry, we discuss writing the components of wave vectors of particles in the form of infinite continued fractions. We show that for $Q^{2} \leq 0.5$ (GeV/c)$^{2}$, where $Q^{2}$ is the transferred momentum squared, electromagnetic form factors that decrease as $Q^{2}$ increases and are close to those experimentally observed in the proton can be obtained without explicitly introducing an internal particle structure.
[ { "created": "Sat, 20 Nov 2010 09:53:29 GMT", "version": "v1" } ]
2011-07-13
[ [ "Slad", "L. M.", "" ] ]
We resolve a number of questions related to an analytic description of electromagnetic form factors of non-Dirac particles with the rest spin 1/2. We find the general structure of a matrix antisymmetric tensor operator. We obtain two recurrence relations for matrix elements of finite transformations of the proper Lorentz group and explicit formulas for a certain set of such elements. Within the theory of fields with double symmetry, we discuss writing the components of wave vectors of particles in the form of infinite continued fractions. We show that for $Q^{2} \leq 0.5$ (GeV/c)$^{2}$, where $Q^{2}$ is the transferred momentum squared, electromagnetic form factors that decrease as $Q^{2}$ increases and are close to those experimentally observed in the proton can be obtained without explicitly introducing an internal particle structure.
hep-ph/0110190
Vladimir Galkin
D. Ebert, R. N. Faustov, V. O. Galkin
Heavy quark potential and mass spectra of heavy mesons
10 pages, plenary talk at the IXth International Conference on Hadron Spectroscopy (August 25-September 1, 2001) - HADRON 2001, Protvino, Russia
AIP Conf.Proc. 619 (2002) 336-345
10.1063/1.1482462
null
hep-ph
null
The relativistic quark model is presented. The quark-antiquark potential for the Schroedinger-like equation is constructed with the account of retardation effects and one-loop radiative corrections. It consists of the one-gluon exchange part and the confining part which is the mixture of the Lorentz scalar and Lorentz vector contributions. The latter contains both the Dirac and Pauli terms. In the v^2/c^2 approximation the mass spectra of heavy quarkonia (charmonium and bottomonium) are calculated in good agreement with experiment. In the case of heavy-light mesons (B and D) the light quark is treated completely relativistically and only the expansion in the inverse heavy quark mass is used. The mass spectra of the ground and excited states of D, D_s, B, B_s mesons are calculated. They exhibit some features of the so-called ``level inversion''. The obtained results are generally in accord with experimental data. Still there exist some discrepancies between measurements of different collaborations.
[ { "created": "Mon, 15 Oct 2001 13:52:45 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ebert", "D.", "" ], [ "Faustov", "R. N.", "" ], [ "Galkin", "V. O.", "" ] ]
The relativistic quark model is presented. The quark-antiquark potential for the Schroedinger-like equation is constructed with the account of retardation effects and one-loop radiative corrections. It consists of the one-gluon exchange part and the confining part which is the mixture of the Lorentz scalar and Lorentz vector contributions. The latter contains both the Dirac and Pauli terms. In the v^2/c^2 approximation the mass spectra of heavy quarkonia (charmonium and bottomonium) are calculated in good agreement with experiment. In the case of heavy-light mesons (B and D) the light quark is treated completely relativistically and only the expansion in the inverse heavy quark mass is used. The mass spectra of the ground and excited states of D, D_s, B, B_s mesons are calculated. They exhibit some features of the so-called ``level inversion''. The obtained results are generally in accord with experimental data. Still there exist some discrepancies between measurements of different collaborations.
2211.04099
Raghav Chaturvedi Dr.
Raghav Chaturvedi, Ajay Kumar Rai
$B_c$ meson spectroscopy motivated by general features of pNRQCD
null
null
10.1140/epja/s10050-022-00884-7
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the present article the mass spectrum, decay constant, weak decay widths, life time and branching fraction ratios and electromagnetic transition widths are calculated for ground and radially excited $B_c$ meson. To calculate the above properties the Schr\"{o}dinger equation has been solved numerically for the potential. The potential employed consists of relativistic correction in the framework of pNRQCD, added to the Cornell potential. The calculated results are compared with available experimental and theoretical results.
[ { "created": "Tue, 8 Nov 2022 08:58:43 GMT", "version": "v1" } ]
2022-12-14
[ [ "Chaturvedi", "Raghav", "" ], [ "Rai", "Ajay Kumar", "" ] ]
In the present article the mass spectrum, decay constant, weak decay widths, life time and branching fraction ratios and electromagnetic transition widths are calculated for ground and radially excited $B_c$ meson. To calculate the above properties the Schr\"{o}dinger equation has been solved numerically for the potential. The potential employed consists of relativistic correction in the framework of pNRQCD, added to the Cornell potential. The calculated results are compared with available experimental and theoretical results.
1103.0969
Ben Allanach PhD
B.C. Allanach, T.J. Khoo, C.G. Lester, S.L. Williams
The impact of the ATLAS zero-lepton, jets and missing momentum search on a CMSSM fit
16 pages, 7 figures. v2 has bigger figures and fixed typos. v3 has clarified explanation of our handling of signal systematics
JHEP06(2011)035
10.1007/JHEP06(2011)035
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent ATLAS data significantly extend the exclusion limits for supersymmetric particles. We examine the impact of such data on global fits of the constrained minimal supersymmetric standard model (CMSSM) to indirect and cosmological data. We calculate the likelihood map of the ATLAS search, taking into account systematic errors on the signal and on the background. We validate our calculation against the ATLAS determinaton of 95% confidence level exclusion contours. A previous CMSSM global fit is then re-weighted by the likelihood map, which takes a bite at the high probability density region of the global fit, pushing scalar and gaugino masses up.
[ { "created": "Fri, 4 Mar 2011 19:57:31 GMT", "version": "v1" }, { "created": "Thu, 10 Mar 2011 10:15:17 GMT", "version": "v2" }, { "created": "Wed, 20 Apr 2011 10:27:50 GMT", "version": "v3" } ]
2015-03-19
[ [ "Allanach", "B. C.", "" ], [ "Khoo", "T. J.", "" ], [ "Lester", "C. G.", "" ], [ "Williams", "S. L.", "" ] ]
Recent ATLAS data significantly extend the exclusion limits for supersymmetric particles. We examine the impact of such data on global fits of the constrained minimal supersymmetric standard model (CMSSM) to indirect and cosmological data. We calculate the likelihood map of the ATLAS search, taking into account systematic errors on the signal and on the background. We validate our calculation against the ATLAS determinaton of 95% confidence level exclusion contours. A previous CMSSM global fit is then re-weighted by the likelihood map, which takes a bite at the high probability density region of the global fit, pushing scalar and gaugino masses up.
hep-ph/0512337
Branimir Zauner
S. Ceci, A. Svarc and B. Zauner
The re-analysis of the 1700 MeV structure of the P11 partial wave using the piN->KLambda production data
17 pages, 3 figures; Accepted for publication in Few Body Systems
FewBodySys.39:27-43,2006
10.1007/s00601-006-0153-3
null
hep-ph
null
We have used the Breit-Wigner resonance model with S11, P11 and P13 resonances in the s-channel to re-analyze the old piN -> KLambda data with the aim to establish the origin of the prominent structure in the total cross section in the vicinity of 1700 MeV. In this paper we show that, at least in the Breit-Wigner resonance model, it is not possible to achieve the detailed reproduction of the narrow 1700 MeV total cross section peak using the standard partial widths. We have found the new set of resonance parameters enforcing the experimentally observed structure of the total cross section data simultaneously with the linear dependence of the differential cross sections with the cos(Theta) in the energy range 1650 MeV < W < 1800 MeV. The result is that the P13 partial wave has been strongly attenuated in this model. To understand the phenomenon, a much narrower width of a resonant state, the N(1710) P11 in our case, is required, but then the agreement of the model predictions with total cross section data at higher energies is lost. One way out is to allow for the existence of the second P11 resonance in that energy range. The same feature is shown by the polarization data. Analyzing the qqq or qqqq(qbar) nature of the recommended narrow P11 structure in the neighbourhood of 1700 MeV we re-open (remind of) the possibility that another P11 resonant state exists in addition to the standard N(1710) P11 PDG-resonance, and that one of the two states can be identified with the yet undiscovered cryptoexotic pentaquark state. To clarify the situation, we strongly recommend remeasurement of the piN -> KLambda process in the energy range 1650 MeV < W < 1800 MeV.
[ { "created": "Tue, 27 Dec 2005 12:16:42 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ceci", "S.", "" ], [ "Svarc", "A.", "" ], [ "Zauner", "B.", "" ] ]
We have used the Breit-Wigner resonance model with S11, P11 and P13 resonances in the s-channel to re-analyze the old piN -> KLambda data with the aim to establish the origin of the prominent structure in the total cross section in the vicinity of 1700 MeV. In this paper we show that, at least in the Breit-Wigner resonance model, it is not possible to achieve the detailed reproduction of the narrow 1700 MeV total cross section peak using the standard partial widths. We have found the new set of resonance parameters enforcing the experimentally observed structure of the total cross section data simultaneously with the linear dependence of the differential cross sections with the cos(Theta) in the energy range 1650 MeV < W < 1800 MeV. The result is that the P13 partial wave has been strongly attenuated in this model. To understand the phenomenon, a much narrower width of a resonant state, the N(1710) P11 in our case, is required, but then the agreement of the model predictions with total cross section data at higher energies is lost. One way out is to allow for the existence of the second P11 resonance in that energy range. The same feature is shown by the polarization data. Analyzing the qqq or qqqq(qbar) nature of the recommended narrow P11 structure in the neighbourhood of 1700 MeV we re-open (remind of) the possibility that another P11 resonant state exists in addition to the standard N(1710) P11 PDG-resonance, and that one of the two states can be identified with the yet undiscovered cryptoexotic pentaquark state. To clarify the situation, we strongly recommend remeasurement of the piN -> KLambda process in the energy range 1650 MeV < W < 1800 MeV.
hep-ph/9706500
null
Mayumi Aoki, Tomoko Kadoyoshi, Akio Sugamoto, Noriyuki Oshimo
Electric Dipole Moments of Neutron and Electron in Supersymmetric Model
16 pages, To appear in the Proceedings of the KEK meetings on 'CP violation and its origin' (1993-1997)
null
null
ICRR-Report-392-97-15, OCHA-PP-98
hep-ph
null
The electric dipole moments (EDMs) of the neutron and the electron are reviewed within the framework of the supersymmetric standard model (SSM) based on grand unified theories coupled to N=1 supergravity. Taking into account one-loop and two-loop contributions to the EDMs, we explore SSM parameter space consistent with experiments and discuss predicted values for the EDMs. Implications of baryon asymmetry of our universe for the EDMs are also discussed.
[ { "created": "Wed, 25 Jun 1997 11:26:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Aoki", "Mayumi", "" ], [ "Kadoyoshi", "Tomoko", "" ], [ "Sugamoto", "Akio", "" ], [ "Oshimo", "Noriyuki", "" ] ]
The electric dipole moments (EDMs) of the neutron and the electron are reviewed within the framework of the supersymmetric standard model (SSM) based on grand unified theories coupled to N=1 supergravity. Taking into account one-loop and two-loop contributions to the EDMs, we explore SSM parameter space consistent with experiments and discuss predicted values for the EDMs. Implications of baryon asymmetry of our universe for the EDMs are also discussed.
hep-ph/9611286
Ben Allanach
B. C. Allanach, G. Amelino-Camelia and O. Philipsen
Infra-red fixed point structure characterising SUSY SU(5) symmetry breaking
10 pages LaTeX, 4 epsf figures. 2 extra references included. Version to appear in Phys Lett B
Phys.Lett. B393 (1997) 349-354
10.1016/S0370-2693(96)01630-9
OUTP-96-63P, RAL-TR-96-090
hep-ph
null
We analyze the one-loop renormalisation group equations for the parameters of the Higgs potential of a supersymmetric SU(5) model with first step of symmetry breaking involving an adjoint Higgs. In particular, we investigate the running of the parameters that decide the first step of symmetry breaking in an attempt to establish which symmetry-breaking scenarios would be most likely if the model is the effective low-energy description of some more fundamental theory. An infra-red fixed point is identified analytically. We show that it is located at the boundary between the region of Higgs parameter space corresponding to unbroken SU(5) and the region corresponding to the breaking of SU(5) to the Standard Model, and we elaborate on its implications. We also observe that certain forms of the Higgs potential discussed at tree level in the literature are not renormalisation group invariant.
[ { "created": "Sat, 9 Nov 1996 11:55:29 GMT", "version": "v1" }, { "created": "Tue, 10 Dec 1996 13:01:43 GMT", "version": "v2" } ]
2009-10-30
[ [ "Allanach", "B. C.", "" ], [ "Amelino-Camelia", "G.", "" ], [ "Philipsen", "O.", "" ] ]
We analyze the one-loop renormalisation group equations for the parameters of the Higgs potential of a supersymmetric SU(5) model with first step of symmetry breaking involving an adjoint Higgs. In particular, we investigate the running of the parameters that decide the first step of symmetry breaking in an attempt to establish which symmetry-breaking scenarios would be most likely if the model is the effective low-energy description of some more fundamental theory. An infra-red fixed point is identified analytically. We show that it is located at the boundary between the region of Higgs parameter space corresponding to unbroken SU(5) and the region corresponding to the breaking of SU(5) to the Standard Model, and we elaborate on its implications. We also observe that certain forms of the Higgs potential discussed at tree level in the literature are not renormalisation group invariant.
hep-ph/0511162
Kiwoon Choi
Kiwoon Choi
Moduli stabilization and the pattern of soft SUSY breaking terms
16 pages, 2 figures, Talk given at Summer Institute 2005, Fuji-Yoshida, August 11-18, 2005 (to be published in the Proceedings)
null
null
KAIST-TH 2005/18
hep-ph
null
In string compactification preserving N=1 SUSY, moduli fields are plausible candidates for the messenger of SUSY breaking at low energy scales. In a scenario that moduli-mediated SUSY breaking is significant, the pattern of soft SUSY breaking terms depends crucially on how the light moduli with mass m \lesssim O(8\pi^2 m_{3/2}) are stabilized. We discuss the correspondence between the pattern of soft terms and the stabilization mechanism of light moduli within the framework of 4D effective supergravity which is generalized to include a SUSY-breaking uplifting potential which might be necessary to get the phenomenologically viable de-Sitter (or Minkowski) vacuum. In some special case, light moduli can be stabilized by controllably small perturbative corrections to the K\"ahler potential, yielding the soft terms dominated by the moduli-mediated contribution. In more generic situation, light moduli are stabilized by non-perturbative effects encoded in the superpotential and a quite different pattern of soft terms emerges: the anomaly-mediated soft terms become comparable to the moduli-mediated ones. Such mixed moduli-anomaly mediated soft terms lead to low energy superparticle masses qualitatively different from those of other mediation models such as mSUGRA scenario, gauge-mediation, and anomaly-mediation.
[ { "created": "Mon, 14 Nov 2005 05:13:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Choi", "Kiwoon", "" ] ]
In string compactification preserving N=1 SUSY, moduli fields are plausible candidates for the messenger of SUSY breaking at low energy scales. In a scenario that moduli-mediated SUSY breaking is significant, the pattern of soft SUSY breaking terms depends crucially on how the light moduli with mass m \lesssim O(8\pi^2 m_{3/2}) are stabilized. We discuss the correspondence between the pattern of soft terms and the stabilization mechanism of light moduli within the framework of 4D effective supergravity which is generalized to include a SUSY-breaking uplifting potential which might be necessary to get the phenomenologically viable de-Sitter (or Minkowski) vacuum. In some special case, light moduli can be stabilized by controllably small perturbative corrections to the K\"ahler potential, yielding the soft terms dominated by the moduli-mediated contribution. In more generic situation, light moduli are stabilized by non-perturbative effects encoded in the superpotential and a quite different pattern of soft terms emerges: the anomaly-mediated soft terms become comparable to the moduli-mediated ones. Such mixed moduli-anomaly mediated soft terms lead to low energy superparticle masses qualitatively different from those of other mediation models such as mSUGRA scenario, gauge-mediation, and anomaly-mediation.
2405.15011
Gordon Baym
Gordon Baym, Jen-Chieh Peng, and C. J. Pethick
Beta decay and related processes from an angular momentum perspective
7 pages, 1 figure
null
null
NORDITA 2024-018
hep-ph hep-th nucl-th quant-ph
http://creativecommons.org/licenses/by/4.0/
We ask the question of how angular momentum is conserved in weak interaction processes, beginning with inverse beta decay for massless neutrinos and electrons, in which both the incident neutrino and final electron are in helicity eigenstates with respect, however, to {\em different} directions. To elucidate the problem we recast the final electron state in terms of a spherical Dirac wave. We then generalize these results to massive neutrinos and electrons, and finally examine electron-positron annihilation processes through the same lens. In all these processes, the apparent non-conservation of angular momentum is a result of the quantum measurement process in which the measuring apparatus is not in an initially well-defined quantum state, but is coupled to the outside world; the measuring process, being outside the rules of elementary quantum mechanics, does not allow a satisfactory accounting of the angular momentum transfer.
[ { "created": "Thu, 23 May 2024 19:34:32 GMT", "version": "v1" } ]
2024-05-27
[ [ "Baym", "Gordon", "" ], [ "Peng", "Jen-Chieh", "" ], [ "Pethick", "C. J.", "" ] ]
We ask the question of how angular momentum is conserved in weak interaction processes, beginning with inverse beta decay for massless neutrinos and electrons, in which both the incident neutrino and final electron are in helicity eigenstates with respect, however, to {\em different} directions. To elucidate the problem we recast the final electron state in terms of a spherical Dirac wave. We then generalize these results to massive neutrinos and electrons, and finally examine electron-positron annihilation processes through the same lens. In all these processes, the apparent non-conservation of angular momentum is a result of the quantum measurement process in which the measuring apparatus is not in an initially well-defined quantum state, but is coupled to the outside world; the measuring process, being outside the rules of elementary quantum mechanics, does not allow a satisfactory accounting of the angular momentum transfer.
1501.04753
Vicent Mateu
Andre H. Hoang, Daniel W. Kolodrubetz, Vicent Mateu, Iain W. Stewart
State-of-the-Art Predictions for C-parameter and a Determination of alpha_s
7 pages, 5 figures, 2 tables. Presented at the 37th International Conference on High Energy Physics (ICHEP)
null
10.1063/1.4938630
UWTHPH 2014-24, MIT-CTP 4601, LPN14-122
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The C-parameter event-shape distribution for e+e- annihilation into hadrons is computed in the framework of SCET including input from fixed-order perturbation theory. We calculate all missing ingredients for achieving N3LL resummation accuracy in the cross section, which is then matched onto O(alpha_s^3) fixed-order results. Hadronization power corrections are incorporated as a convolution with a nonperturbative shape function. Wide-angle soft radiation effects introduce an O(Lambda_QCD) renormalon ambiguity in the cross section, which we cure by switching to the Rgap short-distance scheme. We also include hadron mass effects, but find their effect is rather small. Performing fits to the tail of the C-parameter distribution for many center of mass energies we find that the strong coupling constant is alpha_s(mZ) = 0.1123 +-0.0015, with chi^2/dof=0.99.
[ { "created": "Tue, 20 Jan 2015 10:20:13 GMT", "version": "v1" } ]
2016-02-17
[ [ "Hoang", "Andre H.", "" ], [ "Kolodrubetz", "Daniel W.", "" ], [ "Mateu", "Vicent", "" ], [ "Stewart", "Iain W.", "" ] ]
The C-parameter event-shape distribution for e+e- annihilation into hadrons is computed in the framework of SCET including input from fixed-order perturbation theory. We calculate all missing ingredients for achieving N3LL resummation accuracy in the cross section, which is then matched onto O(alpha_s^3) fixed-order results. Hadronization power corrections are incorporated as a convolution with a nonperturbative shape function. Wide-angle soft radiation effects introduce an O(Lambda_QCD) renormalon ambiguity in the cross section, which we cure by switching to the Rgap short-distance scheme. We also include hadron mass effects, but find their effect is rather small. Performing fits to the tail of the C-parameter distribution for many center of mass energies we find that the strong coupling constant is alpha_s(mZ) = 0.1123 +-0.0015, with chi^2/dof=0.99.
2108.09315
Thomas Steingasser
Justin Khoury, Thomas Steingasser
Gauge hierarchy from electroweak vacuum metastability
v2: 24 pages, 6 figures. To appear in Physical Review D
null
10.1103/PhysRevD.105.055031
null
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We consider the possibility that the gauge hierarchy is a byproduct of the metastability of the electroweak vacuum, i.e., that whatever mechanism is responsible for the latter also sets the running Higgs mass to a value smaller than its natural value by many orders of magnitude. This perspective is motivated by the early-time framework for eternal inflation put forth recently, which favors vacua that are relatively short-lived, but applies more generally to any theoretical approach predicting that our vacuum should be metastable. We find that the metastability of the electroweak vacuum, together with the requirement that such a non-trivial vacuum exists, requires the Higgs mass to be smaller than the instability scale by around one order of magnitude. While this bound is quite weak in the Standard Model (SM), as the instability scale is $\sim 10^{11}$ GeV, simple and well-motivated extensions of the SM - concretely, the $\nu$MSM with an approximate $B-\tilde{L}$ symmetry and the minimal SU(4)/Sp(4) composite Higgs model - can significantly tighten the bound by lowering the instability scale. We find that the bound can be brought down to $\simeq 10$ TeV where our perturbative treatment of the decay rate becomes unreliable. Our results imply that, assuming the SM symmetry breaking pattern, small running Higgs masses are a universal property of theories giving rise to metastability, suggesting a common origin of the two underlying fine-tunings and providing a strong constraint on any attempt to explain metastability.
[ { "created": "Fri, 20 Aug 2021 18:00:03 GMT", "version": "v1" }, { "created": "Mon, 14 Mar 2022 19:00:02 GMT", "version": "v2" } ]
2022-04-13
[ [ "Khoury", "Justin", "" ], [ "Steingasser", "Thomas", "" ] ]
We consider the possibility that the gauge hierarchy is a byproduct of the metastability of the electroweak vacuum, i.e., that whatever mechanism is responsible for the latter also sets the running Higgs mass to a value smaller than its natural value by many orders of magnitude. This perspective is motivated by the early-time framework for eternal inflation put forth recently, which favors vacua that are relatively short-lived, but applies more generally to any theoretical approach predicting that our vacuum should be metastable. We find that the metastability of the electroweak vacuum, together with the requirement that such a non-trivial vacuum exists, requires the Higgs mass to be smaller than the instability scale by around one order of magnitude. While this bound is quite weak in the Standard Model (SM), as the instability scale is $\sim 10^{11}$ GeV, simple and well-motivated extensions of the SM - concretely, the $\nu$MSM with an approximate $B-\tilde{L}$ symmetry and the minimal SU(4)/Sp(4) composite Higgs model - can significantly tighten the bound by lowering the instability scale. We find that the bound can be brought down to $\simeq 10$ TeV where our perturbative treatment of the decay rate becomes unreliable. Our results imply that, assuming the SM symmetry breaking pattern, small running Higgs masses are a universal property of theories giving rise to metastability, suggesting a common origin of the two underlying fine-tunings and providing a strong constraint on any attempt to explain metastability.
1906.00666
Tanmay Kumar Poddar
Tanmay Kumar Poddar, Subhendra Mohanty, Soumya Jana
Constraints on ultra-light axions from compact binary systems
19 pages, 5 figures, 2 tables. Accepted in Phys. Rev. D
Phys. Rev. D 101, 083007 (2020)
10.1103/PhysRevD.101.083007
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultra light particles $(m_a \sim 10^{-21}eV-10^{-22}eV)$ with axion-like couplings to other particles can be candidates for fuzzy dark matter (FDM) if the axion decay constant $f_a\sim 10^{17}GeV$. If a compact star is immersed in such a low mass axionic potential it develops a long range field outside the star. This axionic field is radiated away when the star is in a binary orbit. The orbital period of a compact binary decays mainly due to the gravitational wave radiation, which was confirmed first in the Hulse-Taylor binary pulsar. The orbital period can also decay by radiation of other light particles like axions and axion like particles(ALPs). For axionic radiation to take place, the orbital frequency of the periodic motion of the binary system should be greater than the mass of the scalar particle which can be radiated. This implies that, for most of the observed binaries, particles with mass $m_a< 10^{-19}eV$ can be radiated, which includes FDM particles. In this paper, we consider four compact binary systems: PSR J0348+0432, PSR J0737-3039, PSR J1738+0333, and PSR B1913+16 (Hulse Taylor Binary) and show that the observations of the decay in orbital period put the bound on axion decay constant, $f_a\lesssim \mathcal{O}(10^{11}GeV)$. This implies that Fuzzy Dark Matter cannot couple to gluons.
[ { "created": "Mon, 3 Jun 2019 09:43:00 GMT", "version": "v1" }, { "created": "Fri, 14 Jun 2019 14:39:20 GMT", "version": "v2" }, { "created": "Tue, 24 Mar 2020 14:27:35 GMT", "version": "v3" } ]
2020-04-15
[ [ "Poddar", "Tanmay Kumar", "" ], [ "Mohanty", "Subhendra", "" ], [ "Jana", "Soumya", "" ] ]
Ultra light particles $(m_a \sim 10^{-21}eV-10^{-22}eV)$ with axion-like couplings to other particles can be candidates for fuzzy dark matter (FDM) if the axion decay constant $f_a\sim 10^{17}GeV$. If a compact star is immersed in such a low mass axionic potential it develops a long range field outside the star. This axionic field is radiated away when the star is in a binary orbit. The orbital period of a compact binary decays mainly due to the gravitational wave radiation, which was confirmed first in the Hulse-Taylor binary pulsar. The orbital period can also decay by radiation of other light particles like axions and axion like particles(ALPs). For axionic radiation to take place, the orbital frequency of the periodic motion of the binary system should be greater than the mass of the scalar particle which can be radiated. This implies that, for most of the observed binaries, particles with mass $m_a< 10^{-19}eV$ can be radiated, which includes FDM particles. In this paper, we consider four compact binary systems: PSR J0348+0432, PSR J0737-3039, PSR J1738+0333, and PSR B1913+16 (Hulse Taylor Binary) and show that the observations of the decay in orbital period put the bound on axion decay constant, $f_a\lesssim \mathcal{O}(10^{11}GeV)$. This implies that Fuzzy Dark Matter cannot couple to gluons.
hep-ph/0010093
Alex H. Blin
Alex H. Blin (Universidade de Coimbra, Portugal)
Fluctuations of the Metric Tensor and Fermion Propagators
10 pages, LaTeX, new version with minor revisions
null
null
null
hep-ph gr-qc
null
Conformal fluctuations of the metric tensor at the Planck scale are considered. They give rise to a lower bound of the proper length. This leads to finite expressions for quantities related to propagators without the need of renormalization or regularization. Quantities like the current quark mass or the effective strong coupling constant have to be reinterpreted.
[ { "created": "Tue, 10 Oct 2000 15:41:10 GMT", "version": "v1" }, { "created": "Tue, 3 Apr 2001 16:15:56 GMT", "version": "v2" } ]
2007-05-23
[ [ "Blin", "Alex H.", "", "Universidade de Coimbra, Portugal" ] ]
Conformal fluctuations of the metric tensor at the Planck scale are considered. They give rise to a lower bound of the proper length. This leads to finite expressions for quantities related to propagators without the need of renormalization or regularization. Quantities like the current quark mass or the effective strong coupling constant have to be reinterpreted.