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hep-ph/0505159
Michele Gallinaro
Michele Gallinaro
New Diffractive Results from the Tevatron
4 pages, 4 figures Pub. Proc. of the "40th Rencontres de Moriond on QCD and High Energy Interactions"
null
null
null
hep-ph
null
Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.
[ { "created": "Wed, 18 May 2005 12:46:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gallinaro", "Michele", "" ] ]
Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.
2002.02788
Roman Nevzorov
S. F. King, S. Moretti, R. Nevzorov
A Review of the Exceptional Supersymmetric Standard Model
39 pages, 3 figure. arXiv admin note: text overlap with arXiv:1205.5967, arXiv:hep-ph/0510419
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Local supersymmetry (SUSY) provides an attractive framework for the incorporation of gravity and unification of gauge interactions within Grand Unified Theories (GUTs). Its breakdown can lead to a variety of models with softly broken SUSY at low energies. In this review article we focus on the SUSY extension of the Standard Model (SM) with an extra U(1)_{N} gauge symmetry originating from a string-inspired E_6 grand unified gauge group. Only in this U(1) extension of the minimal supersymmetric standard model (MSSM) inspired by E_6 GUTs the right-handed neutrinos can be superheavy providing a mechanism for the generation of the lepton and baryon asymmetry of the Universe. The particle content of this exceptional supersymmetric standard model (E_6SSM) includes three 27 representations of the E_6 group, to ensure anomaly cancellation, plus a pair of SU(2)_W doublets as required for gauge coupling unification. Thus E_6SSM involves extra exotic matter beyond the MSSM. We consider symmetries that permit to suppress non-diagonal flavour transitions and rapid proton decay, as well as gauge coupling unification, the breakdown of the gauge symmetry and the spectrum of Higgs bosons in this model. The possible Large Hadron Collider (LHC) signatures caused by the presence of exotic states are also discussed.
[ { "created": "Thu, 6 Feb 2020 17:51:36 GMT", "version": "v1" } ]
2020-02-10
[ [ "King", "S. F.", "" ], [ "Moretti", "S.", "" ], [ "Nevzorov", "R.", "" ] ]
Local supersymmetry (SUSY) provides an attractive framework for the incorporation of gravity and unification of gauge interactions within Grand Unified Theories (GUTs). Its breakdown can lead to a variety of models with softly broken SUSY at low energies. In this review article we focus on the SUSY extension of the Standard Model (SM) with an extra U(1)_{N} gauge symmetry originating from a string-inspired E_6 grand unified gauge group. Only in this U(1) extension of the minimal supersymmetric standard model (MSSM) inspired by E_6 GUTs the right-handed neutrinos can be superheavy providing a mechanism for the generation of the lepton and baryon asymmetry of the Universe. The particle content of this exceptional supersymmetric standard model (E_6SSM) includes three 27 representations of the E_6 group, to ensure anomaly cancellation, plus a pair of SU(2)_W doublets as required for gauge coupling unification. Thus E_6SSM involves extra exotic matter beyond the MSSM. We consider symmetries that permit to suppress non-diagonal flavour transitions and rapid proton decay, as well as gauge coupling unification, the breakdown of the gauge symmetry and the spectrum of Higgs bosons in this model. The possible Large Hadron Collider (LHC) signatures caused by the presence of exotic states are also discussed.
hep-ph/9409282
Igor Musatov
I.V. Musatov, V.A. Nikolaev, E. Sorace, M. Tarlini and O.G. Tkachev
Additional Degrees of Freedom in Skyrmion Motion
10 pages, LaTeX, CEBAF-TH-94-12
null
null
null
hep-ph
null
We consider the quantization of chiral solitons with baryon number $B>1$. Classical solitons are obtained within the framework of a variational approach. From the form of the soliton solution it can be seen that besides the group of symmetry describing transformations of the configuration as a whole there are additional symmetries corresponding to internal transformations. Taking into account the additional degrees of freedom leads to some sort of spin alignment for light nuclei and gives constraints on their spectra.
[ { "created": "Mon, 12 Sep 1994 15:58:28 GMT", "version": "v1" }, { "created": "Tue, 29 Nov 1994 02:20:06 GMT", "version": "v2" } ]
2008-02-03
[ [ "Musatov", "I. V.", "" ], [ "Nikolaev", "V. A.", "" ], [ "Sorace", "E.", "" ], [ "Tarlini", "M.", "" ], [ "Tkachev", "O. G.", "" ] ]
We consider the quantization of chiral solitons with baryon number $B>1$. Classical solitons are obtained within the framework of a variational approach. From the form of the soliton solution it can be seen that besides the group of symmetry describing transformations of the configuration as a whole there are additional symmetries corresponding to internal transformations. Taking into account the additional degrees of freedom leads to some sort of spin alignment for light nuclei and gives constraints on their spectra.
hep-ph/9610428
null
S. Hardt, J. Geiss, H. Lenske and U. Mosel
RPA-Approach to the Excitations of the Nucleon, Part II: Phenomenology
33 pages, Latex, 9 Postscpript figures, section on the excited states has been completely rewritten after error was detected, results are now much more encouraging
Nucl.Phys. A627 (1997) 427-459
10.1016/S0375-9474(97)00402-8
UGI-96-23
hep-ph nucl-th
null
The tensor-RPA approach developed previously in part I is applied to the Nambu-Jona-Lasinio (NJL) model. As a first step we investigate the structure of Dirac-Hartree-Fock solutions for a rotationally and isospin invariant ground-state density. Whereas vacuum properties can be reproduced, no solitonic configuration for a system with unit baryon number is found. We then solve the tensor-RPA equation employing simple models of the nucleon ground state. In general the ph interaction effects a decrease of the excited states to lower energies. Due to an enhanced level density at low energies the obtained spectra cannot be matched with the experimental data when a standard MIT-bag configuration is used. However, when the size of the nucleon quark core is reduced to approximately 0.3 fm a fair description of the baryon spectrum in the positive-parity channel is achieved. For this purpose the residual interaction turns out to be crucial and leads to a significant improvement compared with the mean-field spectra.
[ { "created": "Mon, 21 Oct 1996 15:27:13 GMT", "version": "v1" }, { "created": "Tue, 14 Jan 1997 16:53:27 GMT", "version": "v2" }, { "created": "Wed, 2 Jul 1997 18:58:15 GMT", "version": "v3" } ]
2009-10-30
[ [ "Hardt", "S.", "" ], [ "Geiss", "J.", "" ], [ "Lenske", "H.", "" ], [ "Mosel", "U.", "" ] ]
The tensor-RPA approach developed previously in part I is applied to the Nambu-Jona-Lasinio (NJL) model. As a first step we investigate the structure of Dirac-Hartree-Fock solutions for a rotationally and isospin invariant ground-state density. Whereas vacuum properties can be reproduced, no solitonic configuration for a system with unit baryon number is found. We then solve the tensor-RPA equation employing simple models of the nucleon ground state. In general the ph interaction effects a decrease of the excited states to lower energies. Due to an enhanced level density at low energies the obtained spectra cannot be matched with the experimental data when a standard MIT-bag configuration is used. However, when the size of the nucleon quark core is reduced to approximately 0.3 fm a fair description of the baryon spectrum in the positive-parity channel is achieved. For this purpose the residual interaction turns out to be crucial and leads to a significant improvement compared with the mean-field spectra.
hep-ph/0306303
Barbot Cyrille
Cyrille Barbot
Decay of Super-Heavy particles: User guide of the SHdecay program
34 pages, 3 figures, to be submitted in Comput. Phys. Commun
Comput.Phys.Commun.157:63-86,2004
10.1016/S0010-4655(03)00469-7
null
hep-ph
null
I give here a detailed user guide for the C++ program SHdecay, which has been developed for computing the final spectra of stable particles (protons, photons, LSPs, electrons, neutrinos of the three species and their antiparticles) arising from the decay of a super-heavy X particle. It allows to compute in great detail the complete decay cascade for any given decay mode into particles of the Minimal Supersymmetric Standard Model (MSSM). In particular, it takes into account all interactions of the MSSM during the perturbative cascade (including not only QCD, but also the electroweak and 3rd generation Yukawa interactions), and includes a detailed treatment of the SUSY decay cascade (for a given set of parameters) and of the non-perturbative hadronization process. All these features allow us to ensure energy conservation over the whole cascade up to a numerical accuracy of a few per mille. Yet, this program also allows to restrict the computation to QCD or SUSY-QCD frameworks. I detail the input and output files, describe the role of each part of the program, and include some advice for using it best.
[ { "created": "Mon, 30 Jun 2003 15:13:36 GMT", "version": "v1" } ]
2014-11-17
[ [ "Barbot", "Cyrille", "" ] ]
I give here a detailed user guide for the C++ program SHdecay, which has been developed for computing the final spectra of stable particles (protons, photons, LSPs, electrons, neutrinos of the three species and their antiparticles) arising from the decay of a super-heavy X particle. It allows to compute in great detail the complete decay cascade for any given decay mode into particles of the Minimal Supersymmetric Standard Model (MSSM). In particular, it takes into account all interactions of the MSSM during the perturbative cascade (including not only QCD, but also the electroweak and 3rd generation Yukawa interactions), and includes a detailed treatment of the SUSY decay cascade (for a given set of parameters) and of the non-perturbative hadronization process. All these features allow us to ensure energy conservation over the whole cascade up to a numerical accuracy of a few per mille. Yet, this program also allows to restrict the computation to QCD or SUSY-QCD frameworks. I detail the input and output files, describe the role of each part of the program, and include some advice for using it best.
1404.6043
Wang Qing
Nan Chen, Qing Wang, Wei Zhao, Shin-Ted Lin, Qian Yue, Jin Li
Exothermic isospin-violating dark matter after SuperCDMS and CDEX
12 pages, 6 figures
phys. Lett. B743, 205(2015)
10.1016/j.physletb.2015.02.043
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
We show that exothermic isospin-violating dark matter (IVDM) can make the results of the latest CDMS-Si experiment consistent with recent null experiments, such as XENON10, XENON100, LUX, CDEX, and SuperCDMS, whereas for the CoGeNT experiment, a strong tension still persists. For CDMS-Si, separate exothermic dark matter or isospin-violating dark matter cannot fully ameliorate the tensions among these experiments; the tension disappears only if exothermic scattering is combined with an isospin-violating effect of f_n/f_p=-0.7. For such exothermic IVDM to exist, at least a new vector gauge boson (dark photon or dark Z') that connects SM quarks to Majorana-type DM particles is required.
[ { "created": "Thu, 24 Apr 2014 07:35:03 GMT", "version": "v1" }, { "created": "Mon, 28 Apr 2014 01:33:23 GMT", "version": "v2" }, { "created": "Fri, 14 Nov 2014 16:51:52 GMT", "version": "v3" }, { "created": "Mon, 2 Mar 2015 16:03:33 GMT", "version": "v4" } ]
2015-03-03
[ [ "Chen", "Nan", "" ], [ "Wang", "Qing", "" ], [ "Zhao", "Wei", "" ], [ "Lin", "Shin-Ted", "" ], [ "Yue", "Qian", "" ], [ "Li", "Jin", "" ] ]
We show that exothermic isospin-violating dark matter (IVDM) can make the results of the latest CDMS-Si experiment consistent with recent null experiments, such as XENON10, XENON100, LUX, CDEX, and SuperCDMS, whereas for the CoGeNT experiment, a strong tension still persists. For CDMS-Si, separate exothermic dark matter or isospin-violating dark matter cannot fully ameliorate the tensions among these experiments; the tension disappears only if exothermic scattering is combined with an isospin-violating effect of f_n/f_p=-0.7. For such exothermic IVDM to exist, at least a new vector gauge boson (dark photon or dark Z') that connects SM quarks to Majorana-type DM particles is required.
hep-ph/9709264
Edward Shuryak
C.M. Hung and E. Shuryak (Physics Department, State University of New York at Stony Brook)
Equation of State, Radial Flow and Freeze-out in High Energy Heavy Ion Collisions
null
Phys.Rev.C57:1891-1906,1998
10.1103/PhysRevC.57.1891
null
hep-ph
null
We have shown that recent experimental data on radial flow, both from AGS and SPS energies, are in agreement with the Equation of State (EOS) including the QCD phase transition. New hydro-kinetic model (HKM) is developed, which incorporates hydrodynamical treatment of expansion and proper kinetics of the freeze-out. We show that the freeze-out surfaces for different secondaries and different collisions are very different, and they are not at all isotherms (as was assumed in most previous hydro works). Comparison of HKM results with cascade-based event generator RQMD is also made in some details: we found that both EOS and flow are in rather good agreement, while the space-time picture is still somewhat different.
[ { "created": "Fri, 5 Sep 1997 19:37:08 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hung", "C. M.", "", "Physics Department, State University of New\n York at Stony Brook" ], [ "Shuryak", "E.", "", "Physics Department, State University of New\n York at Stony Brook" ] ]
We have shown that recent experimental data on radial flow, both from AGS and SPS energies, are in agreement with the Equation of State (EOS) including the QCD phase transition. New hydro-kinetic model (HKM) is developed, which incorporates hydrodynamical treatment of expansion and proper kinetics of the freeze-out. We show that the freeze-out surfaces for different secondaries and different collisions are very different, and they are not at all isotherms (as was assumed in most previous hydro works). Comparison of HKM results with cascade-based event generator RQMD is also made in some details: we found that both EOS and flow are in rather good agreement, while the space-time picture is still somewhat different.
2303.17171
Hiromasa Takaura
Yuuki Hayashi, Go Mishima, Yukinari Sumino, Hiromasa Takaura
Inclusive $|V_{cb}|$ determination in $\overline{\mathrm{MS}}$ mass scheme using dual-space-renormalon-subtraction method
33 pages, 5 figures, version to appear in PRD
null
null
TU-1183, KEK-TH-2510
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine $|V_{cb}|$ from the inclusive semileptonic decay width of the $B$ meson with the known N$^3$LO perturbative coefficients for the first time in the $\overline{\mathrm{MS}}$ mass scheme. We make use of a recently developed method, dual-space-renormalon-subtraction (DSRS) method, to separate and subtract the order $\Lambda_{\rm QCD}^2/m_b$ infrared renormalon. This allows us to perform the analysis accurately in the $\overline{\mathrm{MS}}$ mass scheme, in which otherwise the perturbative series does not converge well up to the currently calculated perturbation order. Our result reads $|V_{cb}|=0.0415\,(^{+10}_{-12})$, which is consistent with the previous results based on other mass schemes and showing an independent cross check of the current theoretical evaluation of the inclusive decay width.
[ { "created": "Thu, 30 Mar 2023 06:09:16 GMT", "version": "v1" }, { "created": "Mon, 30 Oct 2023 03:29:27 GMT", "version": "v2" } ]
2023-10-31
[ [ "Hayashi", "Yuuki", "" ], [ "Mishima", "Go", "" ], [ "Sumino", "Yukinari", "" ], [ "Takaura", "Hiromasa", "" ] ]
We determine $|V_{cb}|$ from the inclusive semileptonic decay width of the $B$ meson with the known N$^3$LO perturbative coefficients for the first time in the $\overline{\mathrm{MS}}$ mass scheme. We make use of a recently developed method, dual-space-renormalon-subtraction (DSRS) method, to separate and subtract the order $\Lambda_{\rm QCD}^2/m_b$ infrared renormalon. This allows us to perform the analysis accurately in the $\overline{\mathrm{MS}}$ mass scheme, in which otherwise the perturbative series does not converge well up to the currently calculated perturbation order. Our result reads $|V_{cb}|=0.0415\,(^{+10}_{-12})$, which is consistent with the previous results based on other mass schemes and showing an independent cross check of the current theoretical evaluation of the inclusive decay width.
hep-ph/0005238
Raymond R. Volkas
A. Yu. Ignatiev and R. R. Volkas
Discovering mirror particles at the Large Hadron Collider and the implied cold universe
8pages including 1 figure, RevTeX; minor changes and added references; this version accepted by Phys Lett B
Phys.Lett.B487:294-298,2000
10.1016/S0370-2693(00)00836-4
UM-P-00/021
hep-ph astro-ph hep-ex
null
The Mirror Matter or Exact Parity Model sees every standard particle, including the physical neutral Higgs boson, paired with a parity partner. The unbroken parity symmetry forces the mass eigenstate Higgs bosons to be maximal mixtures of the ordinary and mirror Higgs bosons. Each of these mass eigenstates will therefore decay 50% of the time into invisible mirror particles, providing a clear and interesting signature for the Large Hadron Collider (LHC) which could thus establish the existence of the mirror world. However, for this effect to be observable the mass difference between the two eigenstates must be sufficiently large. In this paper, we study cosmological constraints from Big Bang Nucleosynthesis on the mass difference parameter. We find that the temperature of the radiation dominated (RD) phase of the universe should never have exceeded a few 10's of GeV if the mass difference is to be observable at the LHC. Chaotic inflation with very inefficient reheating provides an example of how such a cosmology could arise. We conclude that the LHC could thus discover the mirror world and simultaneously establish an upper bound on the temperature of the RD phase of the universe.
[ { "created": "Wed, 24 May 2000 08:23:47 GMT", "version": "v1" }, { "created": "Fri, 30 Jun 2000 08:39:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ignatiev", "A. Yu.", "" ], [ "Volkas", "R. R.", "" ] ]
The Mirror Matter or Exact Parity Model sees every standard particle, including the physical neutral Higgs boson, paired with a parity partner. The unbroken parity symmetry forces the mass eigenstate Higgs bosons to be maximal mixtures of the ordinary and mirror Higgs bosons. Each of these mass eigenstates will therefore decay 50% of the time into invisible mirror particles, providing a clear and interesting signature for the Large Hadron Collider (LHC) which could thus establish the existence of the mirror world. However, for this effect to be observable the mass difference between the two eigenstates must be sufficiently large. In this paper, we study cosmological constraints from Big Bang Nucleosynthesis on the mass difference parameter. We find that the temperature of the radiation dominated (RD) phase of the universe should never have exceeded a few 10's of GeV if the mass difference is to be observable at the LHC. Chaotic inflation with very inefficient reheating provides an example of how such a cosmology could arise. We conclude that the LHC could thus discover the mirror world and simultaneously establish an upper bound on the temperature of the RD phase of the universe.
1105.3031
Ying Li
Ying Li, Juan Hua
Study of Bs-> \phi l^+ l^-$ Decay in a Single Universal Extra Dimension
13 pages, 16 figures
null
10.1140/epjc/s10052-011-1764-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Utilizing form factors calculated within the light-cone sum rules, we have evaluated the decay branching ratios of $B_s\to \phi\gamma$ and $B_s\to \phi \ell^+\ell^-$ in a single universal extra dimension model (UED), which is viewed as one of the alternative theories beyond the standard model (SM). For the decay $B_s \to \phi \ell^+\ell^-$, the dilepton invariant mass spectra, the forward-backward asymmetry, and double lepton polarization are also calculated. For each case, we compared the obtained results with predictions of the SM. In lower values of the compactification factor 1/R, the only parameter in this model, we see the considerable discrepancy between the UED and SM models. However, when 1/R increases, the results of UED tend to diminish and at $1/R = 1000 \mathrm{GeV}$, two models have approximately the same predictions. Compared with data from CDF of $B_s \to \phi \mu^+ \mu^-$, the 1/R tends to be larger than $350 \mathrm{GeV}$. We also note that the zero crossing point of the forward-backward asymmetry is become smaller, which will be an important plat to prob the contribution from the extra dimension model. The results obtained in this work will be very useful in searching new physics beyond SM. Moreover, the order of magnitude for branching ratios shows a possibility to study these channels at the Large Hadron Collider (LHC), CDF and the future super-B factory.
[ { "created": "Mon, 16 May 2011 08:34:22 GMT", "version": "v1" } ]
2015-05-28
[ [ "Li", "Ying", "" ], [ "Hua", "Juan", "" ] ]
Utilizing form factors calculated within the light-cone sum rules, we have evaluated the decay branching ratios of $B_s\to \phi\gamma$ and $B_s\to \phi \ell^+\ell^-$ in a single universal extra dimension model (UED), which is viewed as one of the alternative theories beyond the standard model (SM). For the decay $B_s \to \phi \ell^+\ell^-$, the dilepton invariant mass spectra, the forward-backward asymmetry, and double lepton polarization are also calculated. For each case, we compared the obtained results with predictions of the SM. In lower values of the compactification factor 1/R, the only parameter in this model, we see the considerable discrepancy between the UED and SM models. However, when 1/R increases, the results of UED tend to diminish and at $1/R = 1000 \mathrm{GeV}$, two models have approximately the same predictions. Compared with data from CDF of $B_s \to \phi \mu^+ \mu^-$, the 1/R tends to be larger than $350 \mathrm{GeV}$. We also note that the zero crossing point of the forward-backward asymmetry is become smaller, which will be an important plat to prob the contribution from the extra dimension model. The results obtained in this work will be very useful in searching new physics beyond SM. Moreover, the order of magnitude for branching ratios shows a possibility to study these channels at the Large Hadron Collider (LHC), CDF and the future super-B factory.
hep-ph/0411061
Alexander Parkhomenko
A.Ya.Parkhomenko (University of Bern, Switzerland & Yaroslavl State University, Russia)
Isospin Amplitude Analysis of $B \to \pi\pi$ Decays within the Standard Model
4 pages, 2 figures, ws-procs10x7.cls used, contribution to the Proceedings of the 32nd International Conference on High Energy Physics (ICHEP'04), Beijing, China (16-22 August, 2004). Typos corrected
null
10.1142/9789812702227_0174
null
hep-ph hep-ex
null
Taking into account the recent measurements of the branching ratios and CP asymmetries in the $B \to \pi\pi$ decays by the BABAR and BELLE collaborations, an amplitude analysis based on the isospin symmetry is reported. These data allow to get an independent determination of the CKM unitarity-triangle angle $\gamma$. One of the best-fit solutions gives the range $\gamma = (65 \pm 5)^\circ$, in excellent agreement with the global CKM fit within the Standard Model. The other parameters from this fit confirm the earlier analyses that the data on $B \to \pi\pi$ decays require various topological amplitudes (neglecting the electroweak ones) to be of comparable magnitude with large strong-phase differences.
[ { "created": "Thu, 4 Nov 2004 16:17:35 GMT", "version": "v1" }, { "created": "Sat, 27 Nov 2004 13:07:57 GMT", "version": "v2" } ]
2017-08-23
[ [ "Parkhomenko", "A. Ya.", "", "University of Bern, Switzerland & Yaroslavl State\n University, Russia" ] ]
Taking into account the recent measurements of the branching ratios and CP asymmetries in the $B \to \pi\pi$ decays by the BABAR and BELLE collaborations, an amplitude analysis based on the isospin symmetry is reported. These data allow to get an independent determination of the CKM unitarity-triangle angle $\gamma$. One of the best-fit solutions gives the range $\gamma = (65 \pm 5)^\circ$, in excellent agreement with the global CKM fit within the Standard Model. The other parameters from this fit confirm the earlier analyses that the data on $B \to \pi\pi$ decays require various topological amplitudes (neglecting the electroweak ones) to be of comparable magnitude with large strong-phase differences.
0811.0117
Claudio Coriano
Claudio Coriano, Marco Guzzi, Nikos Irges, Antonio Mariano
Axion and Neutralinos from Supersymmetric Extensions of the Standard Model with anomalous U(1)'s
Phys.Lett.B Published version, 9 pages, 1 figure
Phys.Lett.B671:87-90,2009
10.1016/j.physletb.2008.12.003
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the conditions under which some supersymmetric generalizations of a class of models descending from string theory allow an axion in the physical spectrum, due to the presence of anomalous abelian gauge interactions. The gauge structure of these constructions involve the Stueckelberg supermultiplet and a supersymmetric version of the Wess-Zumino term for anomaly cancellation. While these conditions are not satisfied by the MSSM superpotential, we show that an axion-like particle appears in the spectrum if extra Standard Model singlets are present. We show that the minimal requirements are met by simple superpotentials in which the singlet superfield is charged under the anomalous U(1). The dark matter sector of these models include an axion and several neutralinos with an axino component.
[ { "created": "Mon, 3 Nov 2008 05:40:24 GMT", "version": "v1" }, { "created": "Fri, 23 Jan 2009 11:02:30 GMT", "version": "v2" } ]
2009-02-02
[ [ "Coriano", "Claudio", "" ], [ "Guzzi", "Marco", "" ], [ "Irges", "Nikos", "" ], [ "Mariano", "Antonio", "" ] ]
We analyze the conditions under which some supersymmetric generalizations of a class of models descending from string theory allow an axion in the physical spectrum, due to the presence of anomalous abelian gauge interactions. The gauge structure of these constructions involve the Stueckelberg supermultiplet and a supersymmetric version of the Wess-Zumino term for anomaly cancellation. While these conditions are not satisfied by the MSSM superpotential, we show that an axion-like particle appears in the spectrum if extra Standard Model singlets are present. We show that the minimal requirements are met by simple superpotentials in which the singlet superfield is charged under the anomalous U(1). The dark matter sector of these models include an axion and several neutralinos with an axino component.
hep-ph/9708361
Jonathan Feng
Jonathan L. Feng (LBNL and UC Berkeley)
New Probes of Supersymmetry Beyond the Minimal Framework
11 pages, LaTeX, to be published in the Proceedings of the 5th International Conference on Supersymmetries in Physics (SUSY 97), Philadelphia, PA, 27-31 May 1997
Nucl.Phys.Proc.Suppl.62:36-46,1998
10.1016/S0920-5632(97)00641-5
LBNL-40404, UCB-PTH-97/30
hep-ph hep-ex
null
If supersymmetry is discovered at future colliders, what can we learn? While our appreciation of the variety of possible supersymmetric models has grown tremendously in recent years, most attempts to answer this question have been in the context of some simple and highly restrictive framework, such as minimal supergravity. In this talk I describe new probes of phenomena that are generic in models beyond the minimal framework. These include tests of supersymmetric flavor and CP violation and probes of kinematically inaccessible superparticle sectors through ``super-oblique corrections.'' Such probes have wide applicability to distinguishing models, from gravity- and gauge-mediated theories to hybrid models and models with flavor symmetries. Examples of measurements at LEP II, the LHC, and the NLC are given.
[ { "created": "Fri, 15 Aug 1997 09:25:28 GMT", "version": "v1" } ]
2011-08-11
[ [ "Feng", "Jonathan L.", "", "LBNL and UC Berkeley" ] ]
If supersymmetry is discovered at future colliders, what can we learn? While our appreciation of the variety of possible supersymmetric models has grown tremendously in recent years, most attempts to answer this question have been in the context of some simple and highly restrictive framework, such as minimal supergravity. In this talk I describe new probes of phenomena that are generic in models beyond the minimal framework. These include tests of supersymmetric flavor and CP violation and probes of kinematically inaccessible superparticle sectors through ``super-oblique corrections.'' Such probes have wide applicability to distinguishing models, from gravity- and gauge-mediated theories to hybrid models and models with flavor symmetries. Examples of measurements at LEP II, the LHC, and the NLC are given.
2106.07434
Jean-Marc Richard
Jean-Marc Richard
Fully heavy multiquarks
Contribution to the 8th Asian-Pacific Few-Body Conference, Kanazawa (Japan), March 2021, to appear in a special issue of Few-Body Systems
null
10.1007/s00601-021-01622-3
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The existence of stable multiquarks made of heavy quarks and antiquarks is discussed in the framework of potential models. It is stressed that the few-body problem should be handled seriously and accurately. No bound state is found within the current models. But resonances are likely present in the spectrum above the lowest threshold.
[ { "created": "Mon, 14 Jun 2021 13:54:56 GMT", "version": "v1" } ]
2021-07-07
[ [ "Richard", "Jean-Marc", "" ] ]
The existence of stable multiquarks made of heavy quarks and antiquarks is discussed in the framework of potential models. It is stressed that the few-body problem should be handled seriously and accurately. No bound state is found within the current models. But resonances are likely present in the spectrum above the lowest threshold.
hep-ph/9704287
Yuval Grossman
Yuval Grossman, Yosef Nir and Mihir P. Worah
A Model Independent Construction of the Unitarity Triangle
14 pages, harvmac, 2 figures uses epsf
Phys.Lett.B407:307-313,1997
10.1016/S0370-2693(97)00675-8
SLAC-PUB-7450, WIS-97/10/Apr-PH
hep-ph
null
In a large class of models, the only significant new physics effect on the CP asymmetries in $B \to \psi K_S$ and $B \to \pi\pi$ decays is a new contribution to the $B-\bar B$ mixing amplitude. This allows a model independent construction of the CKM Unitarity Triangle (up to hadronic uncertainties). Furthermore, the contributions to the mixing from the Standard Model and from the new physics can be disentangled. A serious obstacle to this analysis is an eightfold discrete ambiguity in solving for the angles of the triangle. Several ways to reduce the ambiguity either by making further measurements, or by making further assumptions about the nature of the new physics are described.
[ { "created": "Thu, 10 Apr 1997 17:42:24 GMT", "version": "v1" } ]
2010-11-23
[ [ "Grossman", "Yuval", "" ], [ "Nir", "Yosef", "" ], [ "Worah", "Mihir P.", "" ] ]
In a large class of models, the only significant new physics effect on the CP asymmetries in $B \to \psi K_S$ and $B \to \pi\pi$ decays is a new contribution to the $B-\bar B$ mixing amplitude. This allows a model independent construction of the CKM Unitarity Triangle (up to hadronic uncertainties). Furthermore, the contributions to the mixing from the Standard Model and from the new physics can be disentangled. A serious obstacle to this analysis is an eightfold discrete ambiguity in solving for the angles of the triangle. Several ways to reduce the ambiguity either by making further measurements, or by making further assumptions about the nature of the new physics are described.
2403.10747
Y. M. Cho
Petr Benes, Filip Blaschke, and Y. M. Cho
Electroweak Monopole-Antimonopole Pair Production at LHC
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
One of the urgent issues in high energy physics is the experimental confirmation of the electroweak monopole predicted by the standard model, and currently MoEDAL at LHC is actively searching for the monopole. However, the present LHC cannot produce the monopole if the mass is bigger than 7 TeV, while the monopole mass is expected to be around $M_W/\alpha \simeq 11~\text{TeV}$. In this paper we discuss how LHC could circumbent this energy constraint and produce the monopole even when the mass is bigger than 7 TeV, based on the following ideas. First, in the topological production of the monopole the baby monopole mass at creation could be considerably smaller than the adolescent mass. Second, the binding energy of the monopole-antimonopole pair could effectively reduce the mass of the bound state. We discuss how these ideas can actually be realized at LHC to produce the monopole pairs. In particular, we argue that LHC could produce the baby electroweak monopoles whose mass could be around 5.3 TeV, smaller than the adolescent monopole mass around 11.0 TeV. Moreover, we show that LHC could produce the monopolium bound state with mass around 2.5 TeV, even when the total mass of the monopole-antimonopole pair is around 10.6 TeV. Our analysis could play an important role for MoEDAL experiment.
[ { "created": "Sat, 16 Mar 2024 00:41:31 GMT", "version": "v1" }, { "created": "Tue, 19 Mar 2024 00:34:30 GMT", "version": "v2" }, { "created": "Fri, 5 Apr 2024 10:59:00 GMT", "version": "v3" } ]
2024-04-08
[ [ "Benes", "Petr", "" ], [ "Blaschke", "Filip", "" ], [ "Cho", "Y. M.", "" ] ]
One of the urgent issues in high energy physics is the experimental confirmation of the electroweak monopole predicted by the standard model, and currently MoEDAL at LHC is actively searching for the monopole. However, the present LHC cannot produce the monopole if the mass is bigger than 7 TeV, while the monopole mass is expected to be around $M_W/\alpha \simeq 11~\text{TeV}$. In this paper we discuss how LHC could circumbent this energy constraint and produce the monopole even when the mass is bigger than 7 TeV, based on the following ideas. First, in the topological production of the monopole the baby monopole mass at creation could be considerably smaller than the adolescent mass. Second, the binding energy of the monopole-antimonopole pair could effectively reduce the mass of the bound state. We discuss how these ideas can actually be realized at LHC to produce the monopole pairs. In particular, we argue that LHC could produce the baby electroweak monopoles whose mass could be around 5.3 TeV, smaller than the adolescent monopole mass around 11.0 TeV. Moreover, we show that LHC could produce the monopolium bound state with mass around 2.5 TeV, even when the total mass of the monopole-antimonopole pair is around 10.6 TeV. Our analysis could play an important role for MoEDAL experiment.
1904.02831
Mohammad Nopoush
Mohammad Nopoush
Non-equilibrium hydrodynamics of the quark-gluon plasma
186 pages total, with 168 pages body of dissertation
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
My dissertation is about the formulation and application of anisotropic hydrodynamics as a successful non-equilibrium hydrodynamics model for studying the QGP. For this purpose, I introduce the basic conformal anisotropic hydrodynamics formalism and then explain the ways we included realistic features (bulk degree of freedom, quasiparticle implementation of realistic equation of state, more realistic collisional kernel), to make it a suitable hydrodynamics model for studying the QGP generated in heavy-ion collisions. For verification of our model we have compared the evolution of model parameters predicted by aHydro and vHydro, with exact solution of the Boltzmann equation. However, the system is not conformal and the aHydro needed to be improved to include a realistic prescription for the equation of state which takes care of non-ideal effect in the dynamics. I have then designed a novel method for implementing the realistic equation of state (provided by lattice QCD) in the aHydro formalism. This model, called the quasiparticle aHydro model, integrates the non-conformal effects in the aHydro model. The non-conformal effects are due to strong interactions of plasma constituents which leads to temperature-dependence of the particles' effective mass in the system. Based on the quasiparticle picture, we have developed the quasiparticle aHydro (aHydroQP) model. We have then compared the phenomenological predictions of the aHydroQP model with experimental observations. Comparisons illustrate a high level of consistency between our model and the experimental data. Finally, I have calculated the quark self-energy in an anisotropic QGP. The quark self-energy is important because it encodes the way quarks gain interactional mass while in the hot QGP. I also have presented the calculation of gluon self-energy in hard loop approximation in an anisotropic QGP.
[ { "created": "Fri, 5 Apr 2019 00:15:30 GMT", "version": "v1" } ]
2019-04-08
[ [ "Nopoush", "Mohammad", "" ] ]
My dissertation is about the formulation and application of anisotropic hydrodynamics as a successful non-equilibrium hydrodynamics model for studying the QGP. For this purpose, I introduce the basic conformal anisotropic hydrodynamics formalism and then explain the ways we included realistic features (bulk degree of freedom, quasiparticle implementation of realistic equation of state, more realistic collisional kernel), to make it a suitable hydrodynamics model for studying the QGP generated in heavy-ion collisions. For verification of our model we have compared the evolution of model parameters predicted by aHydro and vHydro, with exact solution of the Boltzmann equation. However, the system is not conformal and the aHydro needed to be improved to include a realistic prescription for the equation of state which takes care of non-ideal effect in the dynamics. I have then designed a novel method for implementing the realistic equation of state (provided by lattice QCD) in the aHydro formalism. This model, called the quasiparticle aHydro model, integrates the non-conformal effects in the aHydro model. The non-conformal effects are due to strong interactions of plasma constituents which leads to temperature-dependence of the particles' effective mass in the system. Based on the quasiparticle picture, we have developed the quasiparticle aHydro (aHydroQP) model. We have then compared the phenomenological predictions of the aHydroQP model with experimental observations. Comparisons illustrate a high level of consistency between our model and the experimental data. Finally, I have calculated the quark self-energy in an anisotropic QGP. The quark self-energy is important because it encodes the way quarks gain interactional mass while in the hot QGP. I also have presented the calculation of gluon self-energy in hard loop approximation in an anisotropic QGP.
2301.08754
Bibhushan Shakya
Bibhushan Shakya
The Tachyonic Higgs and the Inflationary Universe
8 pages, 2 figures
null
null
DESY-23-004
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model Higgs becomes tachyonic at high energy scales according to current measurements. This unstable regime of the Higgs potential can be realized in the early Universe during high scale inflation, potentially with catastrophic consequences. This letter highlights a crucial inherent feature of such configurations that has so far remained ignored: Higgs particle production out of vacuum induced by the rapidly evolving Higgs field, which gets exponentially enhanced due to the tachyonic instability. Such explosive particle production can rapidly drain energy away from the Higgs field, sustaining a significant density of Higgs particles even during inflation, and could initiate a qualitatively different form of preheating in parts of the post-inflationary Universe. Any study of the Higgs field in its tachyonic phase, either during or after inflation, must therefore take this substantial particle energy density into account, which could significantly affect the subsequent evolution of such systems. This could carry important implications for high scale inflation, post-inflationary preheating, observable signals in the cosmic microwave background, gravitational waves, and primordial black holes, as well as deeper concepts ranging from eternal inflation to the metastability of the electroweak vacuum.
[ { "created": "Fri, 20 Jan 2023 19:00:00 GMT", "version": "v1" } ]
2023-01-24
[ [ "Shakya", "Bibhushan", "" ] ]
The Standard Model Higgs becomes tachyonic at high energy scales according to current measurements. This unstable regime of the Higgs potential can be realized in the early Universe during high scale inflation, potentially with catastrophic consequences. This letter highlights a crucial inherent feature of such configurations that has so far remained ignored: Higgs particle production out of vacuum induced by the rapidly evolving Higgs field, which gets exponentially enhanced due to the tachyonic instability. Such explosive particle production can rapidly drain energy away from the Higgs field, sustaining a significant density of Higgs particles even during inflation, and could initiate a qualitatively different form of preheating in parts of the post-inflationary Universe. Any study of the Higgs field in its tachyonic phase, either during or after inflation, must therefore take this substantial particle energy density into account, which could significantly affect the subsequent evolution of such systems. This could carry important implications for high scale inflation, post-inflationary preheating, observable signals in the cosmic microwave background, gravitational waves, and primordial black holes, as well as deeper concepts ranging from eternal inflation to the metastability of the electroweak vacuum.
1607.01512
Rico Z\"ollner
Rico Z\"ollner, Burkhard Kampfer
Holographically emulating sequential versus instantaneous disappearance of vector mesons in a hot environment
11 pages
Phys. Rev. C 94, 045205 (2016)
10.1103/PhysRevC.94.045205
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Descent extensions of the soft-wall model are used to accommodate two variants of Regge trajectories of vector meson excitations. At non-zero temperatures, various options for either sequential or instantaneous disappearance of vector mesons as normalisable modes are found, thus emulating deconfinement at a certain temperature in the order of the (pseudo-) critical temperature of QCD. The crucial role of the blackness function, which steers the thermodynamic properties of the considered system, is highlighted.
[ { "created": "Wed, 6 Jul 2016 08:21:23 GMT", "version": "v1" } ]
2016-10-19
[ [ "Zöllner", "Rico", "" ], [ "Kampfer", "Burkhard", "" ] ]
Descent extensions of the soft-wall model are used to accommodate two variants of Regge trajectories of vector meson excitations. At non-zero temperatures, various options for either sequential or instantaneous disappearance of vector mesons as normalisable modes are found, thus emulating deconfinement at a certain temperature in the order of the (pseudo-) critical temperature of QCD. The crucial role of the blackness function, which steers the thermodynamic properties of the considered system, is highlighted.
hep-ph/0207314
Sabine Kraml
B. Allanach, S. Kraml, W. Porod
Comparison of SUSY mass spectrum calculations
Contribution to SUSY02, 17-23 Jun 2002, DESY Hamburg, 7 pages
null
null
null
hep-ph hep-ex
null
We provide a comparison of the results of four SUSY mass spectrum calculations in mSUGRA: Isajet, SuSpect, SoftSusy, and SPheno. In particular, we focus on the high tan(beta) and focus point regions, where the differences in the results are known to be large.
[ { "created": "Thu, 25 Jul 2002 16:44:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Allanach", "B.", "" ], [ "Kraml", "S.", "" ], [ "Porod", "W.", "" ] ]
We provide a comparison of the results of four SUSY mass spectrum calculations in mSUGRA: Isajet, SuSpect, SoftSusy, and SPheno. In particular, we focus on the high tan(beta) and focus point regions, where the differences in the results are known to be large.
2301.11889
Arvind Bhaskar
Arvind Bhaskar, Yash Chaurasia, Kuldeep Deka, Tanumoy Mandal, Subhadip Mitra, Ananya Mukherjee
Right-handed neutrino pair production via second-generation leptoquarks
11 pages, 4 figures, 3 tables. Matches with the journal version
null
10.1016/j.physletb.2023.138039
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
No direct experimental constraints exist on Leptoquark (LQ) couplings with quarks and right-handed neutrinos (RHNs). If a LQ dominantly couples to RHNs, it can leave unique signatures at the LHC. The RHNs can be produced copiously from LQ decays as long as they are lighter than the LQs. LQ-induced RHN production has never been searched for in experiments. This channel can act as a simultaneous probe for RHNs and LQs that dominantly couple to RHNs. In this paper, we consider all possible charge-$2/3$ and $1/3$ scalar and vector LQs that dominantly couple to second-generation quarks and RHN. We study the pair and single productions of TeV-scale LQs and their subsequent decay to sub-TeV RHNs, realised in the inverse seesaw framework. We also consider RHN pair production through a $t$-channel LQ exchange. The single LQ production and $t$-channel contributions can be significant for large LQ-RHN-quark couplings. We systematically combine events from these processes leading to a pair of RHNs plus jets to study the prospects of LQ-assisted RHN pair production. We analyse the monolepton and opposite-sign dilepton final states and estimate the discovery reach at the high-luminosity LHC.
[ { "created": "Fri, 27 Jan 2023 18:06:14 GMT", "version": "v1" }, { "created": "Fri, 1 Mar 2024 06:07:53 GMT", "version": "v2" } ]
2024-03-04
[ [ "Bhaskar", "Arvind", "" ], [ "Chaurasia", "Yash", "" ], [ "Deka", "Kuldeep", "" ], [ "Mandal", "Tanumoy", "" ], [ "Mitra", "Subhadip", "" ], [ "Mukherjee", "Ananya", "" ] ]
No direct experimental constraints exist on Leptoquark (LQ) couplings with quarks and right-handed neutrinos (RHNs). If a LQ dominantly couples to RHNs, it can leave unique signatures at the LHC. The RHNs can be produced copiously from LQ decays as long as they are lighter than the LQs. LQ-induced RHN production has never been searched for in experiments. This channel can act as a simultaneous probe for RHNs and LQs that dominantly couple to RHNs. In this paper, we consider all possible charge-$2/3$ and $1/3$ scalar and vector LQs that dominantly couple to second-generation quarks and RHN. We study the pair and single productions of TeV-scale LQs and their subsequent decay to sub-TeV RHNs, realised in the inverse seesaw framework. We also consider RHN pair production through a $t$-channel LQ exchange. The single LQ production and $t$-channel contributions can be significant for large LQ-RHN-quark couplings. We systematically combine events from these processes leading to a pair of RHNs plus jets to study the prospects of LQ-assisted RHN pair production. We analyse the monolepton and opposite-sign dilepton final states and estimate the discovery reach at the high-luminosity LHC.
2404.04717
Yasar Hicyilmaz
Rikard Enberg, Ya\c{s}ar Hi\c{c}y{\i}lmaz, Stefano Moretti, Carlos P\'erez de los Heros and Harri Waltari
Constraints on the $X17$ boson from IceCube searches for non-standard interactions of neutrinos
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explain the ATOMKI anomaly with a very light $Z'$ state that features non-anomalous and non-flavour-universal vector and axial-vector couplings to all leptons. This $Z'$ comes from a theoretical framework with a spontaneously broken $U(1)'$ symmetry in addition to the Standard Model (SM) gauge group and is compliant with current measurements of the anomalous magnetic moments of the electron and the muon as well as beam dump experiments. The lepton flavour structure of this model allows for $Z'$ couplings to all light neutrinos, suggesting the possibility of $Z'$-mediated Non-Standard Interactions (NSIs) of neutrinos in matter, so that measurements of the strength parameters of the NSIs can constrain the value of the couplings. We use experimental constraints on NSIs of neutrinos using older TEXONO data and newer IceCube data. The IceCube data, in particular, strongly constrain the flavour universality of the leptonic vector current. The constraints enable us to define the region of parameter space of this theoretical scenario that can be pursued in further phenomenological analyses.
[ { "created": "Sat, 6 Apr 2024 19:41:36 GMT", "version": "v1" } ]
2024-04-09
[ [ "Enberg", "Rikard", "" ], [ "Hiçyılmaz", "Yaşar", "" ], [ "Moretti", "Stefano", "" ], [ "Heros", "Carlos Pérez de los", "" ], [ "Waltari", "Harri", "" ] ]
We explain the ATOMKI anomaly with a very light $Z'$ state that features non-anomalous and non-flavour-universal vector and axial-vector couplings to all leptons. This $Z'$ comes from a theoretical framework with a spontaneously broken $U(1)'$ symmetry in addition to the Standard Model (SM) gauge group and is compliant with current measurements of the anomalous magnetic moments of the electron and the muon as well as beam dump experiments. The lepton flavour structure of this model allows for $Z'$ couplings to all light neutrinos, suggesting the possibility of $Z'$-mediated Non-Standard Interactions (NSIs) of neutrinos in matter, so that measurements of the strength parameters of the NSIs can constrain the value of the couplings. We use experimental constraints on NSIs of neutrinos using older TEXONO data and newer IceCube data. The IceCube data, in particular, strongly constrain the flavour universality of the leptonic vector current. The constraints enable us to define the region of parameter space of this theoretical scenario that can be pursued in further phenomenological analyses.
1711.09643
Josip Trampetic Dr.
Raul Horvat, Josip Trampetic and Jiangyang You
Inferring type and scale of noncommutativity from the PTOLEMY experiment
6 pagees, 1 figure, version of article to be published in EPJC
null
10.1140/epjc/s10052-018-6052-1
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If neutrinos are Dirac particles and their right-handed component can be copiously produced in the early universe, then they could influence a direct observation of the cosmic neutrino background, which, most likely, will come about with the recently proposed PTOLEMY experiment. For the production mechanism of right-handed neutrinos we use a state-of-the-art version of gauge field theory deformed by the spacetime noncommutativity, to disclose by it not only the decoupling temperature for the said neutrino component, but also the otherwise hidden coupling temperature. Considering two relevant processes, the plasmon decay and the neutrino elastic scattering, we study the interplay between the structure of the noncommutativity parameter $\theta^{\mu \nu}$ (type of noncommutativity) and the reheating temperature after inflation to obtain otherwise elusive upper bound on the scale of noncommutativity $\Lambda_{\rm NC}$. If PTOLEMY enhanced capture rate is due to spacetime noncommutativity, we verify that a nontrivial maximum upper bound on $\Lambda_{\rm NC}$ (a way below the Planck scale) emerges for a space-like $\theta^{\mu \nu}$ and sufficiently high reheating temperature.
[ { "created": "Mon, 27 Nov 2017 12:15:58 GMT", "version": "v1" }, { "created": "Sat, 14 Jul 2018 11:42:24 GMT", "version": "v2" } ]
2018-08-15
[ [ "Horvat", "Raul", "" ], [ "Trampetic", "Josip", "" ], [ "You", "Jiangyang", "" ] ]
If neutrinos are Dirac particles and their right-handed component can be copiously produced in the early universe, then they could influence a direct observation of the cosmic neutrino background, which, most likely, will come about with the recently proposed PTOLEMY experiment. For the production mechanism of right-handed neutrinos we use a state-of-the-art version of gauge field theory deformed by the spacetime noncommutativity, to disclose by it not only the decoupling temperature for the said neutrino component, but also the otherwise hidden coupling temperature. Considering two relevant processes, the plasmon decay and the neutrino elastic scattering, we study the interplay between the structure of the noncommutativity parameter $\theta^{\mu \nu}$ (type of noncommutativity) and the reheating temperature after inflation to obtain otherwise elusive upper bound on the scale of noncommutativity $\Lambda_{\rm NC}$. If PTOLEMY enhanced capture rate is due to spacetime noncommutativity, we verify that a nontrivial maximum upper bound on $\Lambda_{\rm NC}$ (a way below the Planck scale) emerges for a space-like $\theta^{\mu \nu}$ and sufficiently high reheating temperature.
hep-ph/9507368
null
Graham G. Ross (CERN and University of Oxford)
Fermion mass prediction from Infra-red fixed points
14 pages
Phys.Lett. B364 (1995) 216-226
10.1016/0370-2693(95)01052-1
CERN-TH.45-162
hep-ph
null
We argue that in a wide class of theories the fermion and soft supersymmetry breaking mass structure is largely determined by the infra-red fixed point structure of the theory lying beyond the \smp We show how knowlege of the symmetries and multiplet content of this theory is sufficient to determine the infra-red structure, illustrating the idea for the case of a simple abelian family symetry. The resulting structure determines the fermion masses and mixing angles in terms of a restricted number of parameters.
[ { "created": "Fri, 21 Jul 1995 10:35:45 GMT", "version": "v1" } ]
2009-10-28
[ [ "Ross", "Graham G.", "", "CERN and University of Oxford" ] ]
We argue that in a wide class of theories the fermion and soft supersymmetry breaking mass structure is largely determined by the infra-red fixed point structure of the theory lying beyond the \smp We show how knowlege of the symmetries and multiplet content of this theory is sufficient to determine the infra-red structure, illustrating the idea for the case of a simple abelian family symetry. The resulting structure determines the fermion masses and mixing angles in terms of a restricted number of parameters.
hep-ph/0002012
Tomislav Prokopec
Michael Joyce, Kimmo Kainulainen, and Tomislav Prokopec
The Quantum Boltzmann Equation in a Nontrivial Background
7 pages, 2 figures, macro sprocl.sty, plenary talk given by T. Prokopec at COSMO-99, Trieste, Italy, Sep 27 - Oct 2, 1999
null
10.1142/9789812792129_0061
UNIL-IPT/00-02 (Feb 2000)
hep-ph
null
This talk is a status report on our study of quantum transport equations relevant for baryogenesis computations. Our main finding is that, as a consequence of localization in space, the quasiparticle picture of the plasma dynamics breaks down at first non-trivial order in gradient expansion. While in this talk we focus on bosons, we expect that a similar picture holds for fermions. We then argue that the quasiparticle picture is recovered in the adiabatic limit of frequent scattering.
[ { "created": "Tue, 1 Feb 2000 18:43:57 GMT", "version": "v1" } ]
2016-11-03
[ [ "Joyce", "Michael", "" ], [ "Kainulainen", "Kimmo", "" ], [ "Prokopec", "Tomislav", "" ] ]
This talk is a status report on our study of quantum transport equations relevant for baryogenesis computations. Our main finding is that, as a consequence of localization in space, the quasiparticle picture of the plasma dynamics breaks down at first non-trivial order in gradient expansion. While in this talk we focus on bosons, we expect that a similar picture holds for fermions. We then argue that the quasiparticle picture is recovered in the adiabatic limit of frequent scattering.
hep-ph/9704333
Igor Solovtsov
D.V. Shirkov and I.L. Solovtsov
Analytic Model for the QCD Running Coupling with Universal $\bar{\alpha}_s(0)$ Value
8 pages, LaTex with psfig.sty, 2 PostScript figures
Phys.Rev.Lett. 79 (1997) 1209-1212
10.1103/PhysRevLett.79.1209
JINR E2-97-133
hep-ph
null
We discuss the new model expression $\bar{\alpha}_{an}(Q^2)$ recently obtained for the QCD running coupling with a regular ghost-free behavior in the "low $Q^2$" region. Being deduced from the standard "asymptotic-freedom" expression by imposing the $Q^2$-analyticity -- without any adjustable parameters -- it obeys nice features: (i) The universal limiting value $\bar{\alpha}_{an}(0)=4\pi /\beta_0 \simeq 1.4$ expressed only via group symmetry factors and independent of experimental estimates on the running coupling $\bar{\alpha}_s(Q^2)$ (of QCD scale parameter $\Lambda$). This value turns out to be stable with respect to higher order corrections; (ii) Stability of IR behavior with respect to higher-loop effects; (iii) Coherence between the experimental $\bar{\alpha}_{an}(M_{\tau}^2)$ value and integral information on IR $\bar{\alpha}_s(Q^2)$ behavior as extracted from jet physics data.
[ { "created": "Wed, 16 Apr 1997 04:58:30 GMT", "version": "v1" } ]
2009-10-30
[ [ "Shirkov", "D. V.", "" ], [ "Solovtsov", "I. L.", "" ] ]
We discuss the new model expression $\bar{\alpha}_{an}(Q^2)$ recently obtained for the QCD running coupling with a regular ghost-free behavior in the "low $Q^2$" region. Being deduced from the standard "asymptotic-freedom" expression by imposing the $Q^2$-analyticity -- without any adjustable parameters -- it obeys nice features: (i) The universal limiting value $\bar{\alpha}_{an}(0)=4\pi /\beta_0 \simeq 1.4$ expressed only via group symmetry factors and independent of experimental estimates on the running coupling $\bar{\alpha}_s(Q^2)$ (of QCD scale parameter $\Lambda$). This value turns out to be stable with respect to higher order corrections; (ii) Stability of IR behavior with respect to higher-loop effects; (iii) Coherence between the experimental $\bar{\alpha}_{an}(M_{\tau}^2)$ value and integral information on IR $\bar{\alpha}_s(Q^2)$ behavior as extracted from jet physics data.
hep-ph/9409293
null
M. Kirchbach and H. Arenhoevel
$f_1$ Vector Meson Dominance Model for the Strange Axial Form Factor of the Nucleon
5 pages, latex + 2ps files
null
null
null
hep-ph
null
The axial strange form factor $F^s_A$ of the nucleon is assumed to be dominated at low momentum transfer by the isoscalar axial vector mesons $f_1(1285)$ and $f_1(1420)$. The importance of the $a_0\pi N$-triangular vertex correction is demonstrated.
[ { "created": "Tue, 13 Sep 1994 11:19:35 GMT", "version": "v1" } ]
2009-09-25
[ [ "Kirchbach", "M.", "" ], [ "Arenhoevel", "H.", "" ] ]
The axial strange form factor $F^s_A$ of the nucleon is assumed to be dominated at low momentum transfer by the isoscalar axial vector mesons $f_1(1285)$ and $f_1(1420)$. The importance of the $a_0\pi N$-triangular vertex correction is demonstrated.
2102.05040
Christoph M\"uller
Christoph M\"uller
Top-pair production via gluon fusion in the Standard Model Effective Field Theory
null
null
10.1103/PhysRevD.104.095003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the leading corrections to the differential cross section for top-pair production via gluon fusion due to dimension-six operators at leading order in QCD. The Standard Model fields are assumed to couple only weakly to the hypothetical new sector. A systematic approach then suggests treating single insertions of the operator class containing gluon field strength tensors on the same footing as expli\-citly loop suppressed contributions from four-fermion operators. This is in particular the case for the chromomagnetic operator $Q_{(uG)}$ and the purely bosonic operators $Q_{(G)}$ and $Q_{(\varphi G)}$. All leading order dimension-six contributions are consequently suppressed with a loop factor $1/16\pi^2$.
[ { "created": "Tue, 9 Feb 2021 12:36:56 GMT", "version": "v1" } ]
2021-11-17
[ [ "Müller", "Christoph", "" ] ]
We compute the leading corrections to the differential cross section for top-pair production via gluon fusion due to dimension-six operators at leading order in QCD. The Standard Model fields are assumed to couple only weakly to the hypothetical new sector. A systematic approach then suggests treating single insertions of the operator class containing gluon field strength tensors on the same footing as expli\-citly loop suppressed contributions from four-fermion operators. This is in particular the case for the chromomagnetic operator $Q_{(uG)}$ and the purely bosonic operators $Q_{(G)}$ and $Q_{(\varphi G)}$. All leading order dimension-six contributions are consequently suppressed with a loop factor $1/16\pi^2$.
2302.11183
Junichiro Kawamura
Yoshihiko Abe, Tetsutaro Higaki, Junichiro Kawamura and Tatsuo Kobayashi
Quark and lepton hierarchies from $S_4^\prime$ modular flavor symmetry
15 pages, 3 tables
null
10.1016/j.physletb.2023.137977
CTPU-PTC-23-04, EPHOU-23-006
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose models in which the hierarchical structures of the masses and mixing in both quark and lepton sectors are explained by the $S_4^\prime$ modular flavor symmetry near the fixed point $\tau \sim i\infty$. The model provides the first explicit example which explains hierarchies of both quarks and leptons. The hierarchies are realized by powers of $\epsilon = e^{2\pi i \tau/4} = \mathcal{O}(0.01)$ and $2\,\mathrm{Im}\,\tau \sim 5$, where $\tau$ being the modulus. The small parameter $\epsilon$ plays a role of flavon in the Froggatt-Nielsen mechanism under the residual $Z_4^T$ symmetry, and powers of $2\,\mathrm{Im}\,\tau$ in the Yukawa couplings are controlled by modular weights via the canonical normalization. The doublet quarks are identified to a $S_4^\prime$ triplet to explain the hierarchical structure of the quark mixing angles, while the doublet leptons are composed of three singlets for the large mixing angles in the lepton sector. We show that the $S_4^\prime$ modular symmetry alone can explain the hierarchies in both quark and lepton sectors by $\mathcal{O}(1)$ coefficients.
[ { "created": "Wed, 22 Feb 2023 07:33:59 GMT", "version": "v1" } ]
2023-06-14
[ [ "Abe", "Yoshihiko", "" ], [ "Higaki", "Tetsutaro", "" ], [ "Kawamura", "Junichiro", "" ], [ "Kobayashi", "Tatsuo", "" ] ]
We propose models in which the hierarchical structures of the masses and mixing in both quark and lepton sectors are explained by the $S_4^\prime$ modular flavor symmetry near the fixed point $\tau \sim i\infty$. The model provides the first explicit example which explains hierarchies of both quarks and leptons. The hierarchies are realized by powers of $\epsilon = e^{2\pi i \tau/4} = \mathcal{O}(0.01)$ and $2\,\mathrm{Im}\,\tau \sim 5$, where $\tau$ being the modulus. The small parameter $\epsilon$ plays a role of flavon in the Froggatt-Nielsen mechanism under the residual $Z_4^T$ symmetry, and powers of $2\,\mathrm{Im}\,\tau$ in the Yukawa couplings are controlled by modular weights via the canonical normalization. The doublet quarks are identified to a $S_4^\prime$ triplet to explain the hierarchical structure of the quark mixing angles, while the doublet leptons are composed of three singlets for the large mixing angles in the lepton sector. We show that the $S_4^\prime$ modular symmetry alone can explain the hierarchies in both quark and lepton sectors by $\mathcal{O}(1)$ coefficients.
hep-ph/0204298
Magno Machado
M.B. Gay Ducati, M.V.T. Machado
Unitarity Corrections and Structure Functions
9 pages, 4 figures, uses aip style . Talk presented by M.B. Gay Ducati at the Pan American Advanced Studies Institute (PASI2002), January 7-18, 2002
null
10.1063/1.1513705
null
hep-ph
null
We have studied the color dipole picture for the description of the deep inelastic process, mainly the structure functions which are driven directly by the gluon distribution. Estimates for those functions are obtained using the effective dipole cross section given by the Glauber-Mueller approach in QCD, encoding the corrections due to the unitarity effects associated with the saturation phenomenon. Frame invariance is verified in the calculations of the observables when analysing the experimental data.
[ { "created": "Thu, 25 Apr 2002 14:20:19 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ducati", "M. B. Gay", "" ], [ "Machado", "M. V. T.", "" ] ]
We have studied the color dipole picture for the description of the deep inelastic process, mainly the structure functions which are driven directly by the gluon distribution. Estimates for those functions are obtained using the effective dipole cross section given by the Glauber-Mueller approach in QCD, encoding the corrections due to the unitarity effects associated with the saturation phenomenon. Frame invariance is verified in the calculations of the observables when analysing the experimental data.
1604.04979
Kwei-Chou Yang
Kwei-Chou Yang
Fermionic Dark Matter through a Light Pseudoscalar Portal: Hints from the DAMA Results
31 pages, 6 figures, 7 tables, typos in Sec. IV corrected
Phys. Rev. D 94, 035028 (2016)
10.1103/PhysRevD.94.035028
CYCU-HEP-16-03
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fermionic dark matter (DM) particle interacting with Standard Model quarks via a light pseudoscalar mediator. We consider separately the scenarios for which the DM-pseudoscalar coupling is $CP$ conserving or $CP$ violating. We show that taking a contact interaction is not suitable, even when the mediator has a mass of the same order of magnitude as the typical momentum transfer at the direct-detection experiments, such that the allowed DAMA region is excluded or considerably modified by the correct relic density requirement. The DAMA result seems to indicate that the $CP$-violating interaction is dominant at direct searches. We find that, if the proton-to-neutron effective coupling ratio is $-60\sim -40$, the exclusion limits set by SuperCDMS, XENON100, and LUX are highly suppressed, and the DAMA signal can thus be easily reconciled with these null measurements. For this model, the allowed region determined by the DAMA signal and correct relic density can successfully satisfy the conditions required by the thermal equilibrium, big bang nucleosynthesis, and DM self-interactions. The results of future measurements on flavor physics will provide important constraints on the related models. Precise measurements performed by COUPP, PICASSO, SIMPLE and KIMS should be able to test this model in the near future.
[ { "created": "Mon, 18 Apr 2016 03:55:23 GMT", "version": "v1" }, { "created": "Sat, 21 May 2016 07:48:07 GMT", "version": "v2" }, { "created": "Mon, 29 Aug 2016 02:01:39 GMT", "version": "v3" }, { "created": "Wed, 21 Dec 2016 17:04:52 GMT", "version": "v4" } ]
2016-12-22
[ [ "Yang", "Kwei-Chou", "" ] ]
We study the fermionic dark matter (DM) particle interacting with Standard Model quarks via a light pseudoscalar mediator. We consider separately the scenarios for which the DM-pseudoscalar coupling is $CP$ conserving or $CP$ violating. We show that taking a contact interaction is not suitable, even when the mediator has a mass of the same order of magnitude as the typical momentum transfer at the direct-detection experiments, such that the allowed DAMA region is excluded or considerably modified by the correct relic density requirement. The DAMA result seems to indicate that the $CP$-violating interaction is dominant at direct searches. We find that, if the proton-to-neutron effective coupling ratio is $-60\sim -40$, the exclusion limits set by SuperCDMS, XENON100, and LUX are highly suppressed, and the DAMA signal can thus be easily reconciled with these null measurements. For this model, the allowed region determined by the DAMA signal and correct relic density can successfully satisfy the conditions required by the thermal equilibrium, big bang nucleosynthesis, and DM self-interactions. The results of future measurements on flavor physics will provide important constraints on the related models. Precise measurements performed by COUPP, PICASSO, SIMPLE and KIMS should be able to test this model in the near future.
1109.3140
Dubravko Klabu\v{c}ar
Sanjin Benic and Dubravko Klabucar
Axial anomaly and the interplay of quark loops with pseudoscalar and vector mesons in the gamma* --> pi+ pi0 pi- process
21 pages, 8 eps figures, revtex4, a factor of 2 in resonant contribution corrected, three figures revised and one added, discussion enlarged and references added
null
10.1103/PhysRevD.85.034042
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the ongoing measurements of the Primakoff process pi- gamma* --> pi- pi0 by COMPASS collaboration at CERN, the transition form factor for the canonical anomalous process gamma* --> pi+ pi0 pi- is calculated in a constituent quark loop model. The simplest contribution to this process is the quark "box" amplitude. In the present paper we also explicitly include the vector meson degrees of freedom, i.e., the rho and the omega, thus giving rise to additional, resonant contributions. We find that in order to satisfy the axial anomaly result, a further subtraction in the resonant part is needed. The results are then compared with the vector meson dominance model as well as the Dyson--Schwinger calculations, the chiral perturbation theory result, and the available data.
[ { "created": "Wed, 14 Sep 2011 17:21:09 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2012 18:00:53 GMT", "version": "v2" } ]
2013-05-30
[ [ "Benic", "Sanjin", "" ], [ "Klabucar", "Dubravko", "" ] ]
Motivated by the ongoing measurements of the Primakoff process pi- gamma* --> pi- pi0 by COMPASS collaboration at CERN, the transition form factor for the canonical anomalous process gamma* --> pi+ pi0 pi- is calculated in a constituent quark loop model. The simplest contribution to this process is the quark "box" amplitude. In the present paper we also explicitly include the vector meson degrees of freedom, i.e., the rho and the omega, thus giving rise to additional, resonant contributions. We find that in order to satisfy the axial anomaly result, a further subtraction in the resonant part is needed. The results are then compared with the vector meson dominance model as well as the Dyson--Schwinger calculations, the chiral perturbation theory result, and the available data.
0708.0989
Christoph Luhn
Herbi K. Dreiner, Christoph Luhn, Hitoshi Murayama, Marc Thormeier
Proton Hexality from an Anomalous Flavor U(1) and Neutrino Masses - Linking to the String Scale
32 pages, 8 tables, references updated, matches published version
Nucl.Phys.B795:172-200,2008
10.1016/j.nuclphysb.2007.11.014
UFIFT-HEP-07-11
hep-ph hep-th
null
We devise minimalistic gauged U(1)_X Froggatt-Nielsen models which at low-energy give rise to the recently suggested discrete gauge Z_6 symmetry, proton hexality, thus stabilizing the proton. Assuming three generations of right-handed neutrinos, with the proper choice of X-charges, we obtain viable neutrino masses. Furthermore, we find scenarios such that no X-charged hidden sector superfields are needed, which from a bottom-up perspective allows the calculation of g_string, g_X and G_SM's Kac-Moody levels. The only mass scale apart from M_grav is m_soft.
[ { "created": "Tue, 7 Aug 2007 17:09:44 GMT", "version": "v1" }, { "created": "Thu, 6 Dec 2007 03:34:32 GMT", "version": "v2" } ]
2008-11-26
[ [ "Dreiner", "Herbi K.", "" ], [ "Luhn", "Christoph", "" ], [ "Murayama", "Hitoshi", "" ], [ "Thormeier", "Marc", "" ] ]
We devise minimalistic gauged U(1)_X Froggatt-Nielsen models which at low-energy give rise to the recently suggested discrete gauge Z_6 symmetry, proton hexality, thus stabilizing the proton. Assuming three generations of right-handed neutrinos, with the proper choice of X-charges, we obtain viable neutrino masses. Furthermore, we find scenarios such that no X-charged hidden sector superfields are needed, which from a bottom-up perspective allows the calculation of g_string, g_X and G_SM's Kac-Moody levels. The only mass scale apart from M_grav is m_soft.
hep-ph/9510406
Res Urech
Thomas Mannel and Res Urech
Hadronic Decays of Excited Heavy Quarkonia
Latex (uses epsf.sty), 10 pages, 1 Postscript figure in a separate file. The complete paper, including the figure, is also available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Z.Phys. C73 (1997) 541-546
null
TTP95-36
hep-ph
null
We construct an effective Lagrangian for the hadronic decays of a heavy excited $s$-wave-spin-one quarkonium into its ground state. We show that reasonable fits to the measured invariant mass spectra in the $J/\psi$ and $\Upsilon$ systems can be obtained working in the chiral limit. The mass dependence of the various terms in the Lagrangian is discussed on the basis of a quark model.
[ { "created": "Wed, 25 Oct 1995 16:02:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mannel", "Thomas", "" ], [ "Urech", "Res", "" ] ]
We construct an effective Lagrangian for the hadronic decays of a heavy excited $s$-wave-spin-one quarkonium into its ground state. We show that reasonable fits to the measured invariant mass spectra in the $J/\psi$ and $\Upsilon$ systems can be obtained working in the chiral limit. The mass dependence of the various terms in the Lagrangian is discussed on the basis of a quark model.
hep-ph/0702078
Thomas G. Rizzo
Hooman Davoudiasl and Thomas G. Rizzo
Signatures of Spherical Compactification at the LHC
21 pages, 5 figs
Phys.Rev.D76:055009,2007
10.1103/PhysRevD.76.055009
BNL-HET-07/4, SLAC-PUB-12327
hep-ph hep-ex hep-th
null
TeV-scale extra dimensions may play an important role in electroweak or supersymmetry breaking. We examine the phenomenology of such dimensions, compactified on a sphere $S^n$, $n \geq 2$, and show that they possess distinct features and signatures. For example, unlike flat toroidal manifolds, spheres do not trivially allow fermion massless modes. Acceptable phenomenology then generically leads to "non-universal" extra dimensions with "pole-localized" 4-$d$ fermions; the bosonic fields can be in the bulk. Due to spherical symmetry, some Kaluza-Klein (KK) modes of bulk gauge fields are either stable or extremely long-lived, depending on the graviton KK spectrum. Using precision electroweak data, we constrain the lightest gauge field KK modes to lie above $\simeq 4$ TeV. We show that some of these KK resonances are within the reach of the LHC in several different production channels. The models we study can be uniquely identified by their collider signatures.
[ { "created": "Wed, 7 Feb 2007 16:54:17 GMT", "version": "v1" }, { "created": "Fri, 30 Mar 2007 15:23:25 GMT", "version": "v2" } ]
2008-11-26
[ [ "Davoudiasl", "Hooman", "" ], [ "Rizzo", "Thomas G.", "" ] ]
TeV-scale extra dimensions may play an important role in electroweak or supersymmetry breaking. We examine the phenomenology of such dimensions, compactified on a sphere $S^n$, $n \geq 2$, and show that they possess distinct features and signatures. For example, unlike flat toroidal manifolds, spheres do not trivially allow fermion massless modes. Acceptable phenomenology then generically leads to "non-universal" extra dimensions with "pole-localized" 4-$d$ fermions; the bosonic fields can be in the bulk. Due to spherical symmetry, some Kaluza-Klein (KK) modes of bulk gauge fields are either stable or extremely long-lived, depending on the graviton KK spectrum. Using precision electroweak data, we constrain the lightest gauge field KK modes to lie above $\simeq 4$ TeV. We show that some of these KK resonances are within the reach of the LHC in several different production channels. The models we study can be uniquely identified by their collider signatures.
hep-ph/0511022
Patricia Ball
Angelique N. Talbot
Non-leptonic B-decays in and beyond QCD Factorisation
132 pages, PHD thesis; full text with high-resolution figures available from http://www.ippp.dur.ac.uk/Research/Theses/talbot.ps.gz
null
null
null
hep-ph
null
This thesis examines the non-leptonic B-decays within QCD factorisation and beyond, to challenge the assumptions and limitations of the method. We analyse the treatment of the distribution amplitudes of light mesons and present a new model described by simple physical parameters. The leading twist distribution amplitudes of light mesons describe the leading non-perturbative hadronic contributions to exclusive QCD reactions at large energy transfer, for instance electromagnetic form factors. Importantly, they also enter into the two-body B decay amplitudes described by QCD factorisation. They cannot be calculated from first principles and are described by models based on a fixed-order conformal expansion, which is not always sufficient in phenomenological applications. We derive new models that are valid to all orders in the conformal expansion and characterised by a small number of parameters related to experimental observables.Motivated by the marginal agreement between the QCD factorisation results with the experimental data, in particular for $B\to\pi\pi$, we scrutinise the incalculable non-factorisable corrections to charmless non-leptonic decays. We use the available results on $B\to\pi\pi$ to extract information about the size and nature of the required non-factorisable corrections that are needed to reconcile the predictions and data. We find that the best-fit scenarios do not give reasonable agreement to $2\sigma$ until at least a 40% non-factorisable contribution is added. Finally we consider the exclusive $B\to V\gamma$ decays, where we analyse the recently updated experimental data within QCD factorisation and present constraints on generic supersymmetric models using the mass insertion approximation.
[ { "created": "Wed, 2 Nov 2005 20:41:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Talbot", "Angelique N.", "" ] ]
This thesis examines the non-leptonic B-decays within QCD factorisation and beyond, to challenge the assumptions and limitations of the method. We analyse the treatment of the distribution amplitudes of light mesons and present a new model described by simple physical parameters. The leading twist distribution amplitudes of light mesons describe the leading non-perturbative hadronic contributions to exclusive QCD reactions at large energy transfer, for instance electromagnetic form factors. Importantly, they also enter into the two-body B decay amplitudes described by QCD factorisation. They cannot be calculated from first principles and are described by models based on a fixed-order conformal expansion, which is not always sufficient in phenomenological applications. We derive new models that are valid to all orders in the conformal expansion and characterised by a small number of parameters related to experimental observables.Motivated by the marginal agreement between the QCD factorisation results with the experimental data, in particular for $B\to\pi\pi$, we scrutinise the incalculable non-factorisable corrections to charmless non-leptonic decays. We use the available results on $B\to\pi\pi$ to extract information about the size and nature of the required non-factorisable corrections that are needed to reconcile the predictions and data. We find that the best-fit scenarios do not give reasonable agreement to $2\sigma$ until at least a 40% non-factorisable contribution is added. Finally we consider the exclusive $B\to V\gamma$ decays, where we analyse the recently updated experimental data within QCD factorisation and present constraints on generic supersymmetric models using the mass insertion approximation.
hep-ph/0108058
Helmut Satz
S. Fortunato and H. Satz
Cluster Percolation and First Order Phase Transitions in the Potts Model
11 pages, 6 figures
Nucl.Phys. B623 (2002) 493-502
10.1016/S0550-3213(01)00604-6
BI-TP 2001/16
hep-ph cond-mat hep-lat hep-th
null
The q-state Potts model can be formulated in geometric terms, with Fortuin-Kasteleyn (FK) clusters as fundamental objects. If the phase transition of the model is second order, it can be equivalently described as a percolation transition of FK clusters. In this work, we study the percolation structure when the model undergoes a first order phase transition. In particular, we investigate numerically the percolation behaviour along the line of first order phase transitions of the 3d 3-state Potts model in an external field and find that the percolation strength exhibits a discontinuity along the entire line. The endpoint is also a percolation point for the FK clusters, but the corresponding critical exponents are neither in the Ising nor in the random percolation universality class.
[ { "created": "Mon, 6 Aug 2001 14:48:51 GMT", "version": "v1" } ]
2009-11-07
[ [ "Fortunato", "S.", "" ], [ "Satz", "H.", "" ] ]
The q-state Potts model can be formulated in geometric terms, with Fortuin-Kasteleyn (FK) clusters as fundamental objects. If the phase transition of the model is second order, it can be equivalently described as a percolation transition of FK clusters. In this work, we study the percolation structure when the model undergoes a first order phase transition. In particular, we investigate numerically the percolation behaviour along the line of first order phase transitions of the 3d 3-state Potts model in an external field and find that the percolation strength exhibits a discontinuity along the entire line. The endpoint is also a percolation point for the FK clusters, but the corresponding critical exponents are neither in the Ising nor in the random percolation universality class.
hep-ph/0012095
Alexander S. Sakharov
Jiawei Zhao (on the behalf of the L3 Collaboration)
QED Test at LEP200 Energies in the Reaction $\rm e^+ e^-\to \gamma\gamma (\gamma)$
The change in the list of authors has been made. L3 Collaboration: http://hpl3sn02.cern.ch
null
null
null
hep-ph hep-th
null
The measurements of the QED reaction $ \EEGG $ performed with the L3 detector are used to search for new physics phenomena beyond the Standard Model. No evidence for these phenomena is found and new limits on their parameters are set. First the reaction is used to constrain a model of an excited electron and second to study contact interactions. The total and differential cross sections for the process $ \EEGG $, are measured at energies from 91 GeV to 202 GeV using the data collected with the L3 detector from 1991 to 1999. The L3 data set lower limits on the mass of an excited electron $ \MESTAR > 402 $ GeV, on the QED cutoff parameters $ \LAMP > 415 $ GeV, $ \LAMM > 258 $ GeV and on the contact interaction energy scale $ \Lambda > 1687 $ GeV. The last parameter limits the size of the interaction area to $ R < 1.17\times 10^{-17} $ cm. Some limits on the string and quantum gravity scales are also discussed.
[ { "created": "Fri, 8 Dec 2000 12:40:59 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2000 10:23:18 GMT", "version": "v2" }, { "created": "Tue, 4 Dec 2001 23:54:44 GMT", "version": "v3" }, { "created": "Sat, 6 Apr 2002 20:05:32 GMT", "version": "v4" } ]
2007-05-23
[ [ "Zhao", "Jiawei", "", "on the behalf of the L3 Collaboration" ] ]
The measurements of the QED reaction $ \EEGG $ performed with the L3 detector are used to search for new physics phenomena beyond the Standard Model. No evidence for these phenomena is found and new limits on their parameters are set. First the reaction is used to constrain a model of an excited electron and second to study contact interactions. The total and differential cross sections for the process $ \EEGG $, are measured at energies from 91 GeV to 202 GeV using the data collected with the L3 detector from 1991 to 1999. The L3 data set lower limits on the mass of an excited electron $ \MESTAR > 402 $ GeV, on the QED cutoff parameters $ \LAMP > 415 $ GeV, $ \LAMM > 258 $ GeV and on the contact interaction energy scale $ \Lambda > 1687 $ GeV. The last parameter limits the size of the interaction area to $ R < 1.17\times 10^{-17} $ cm. Some limits on the string and quantum gravity scales are also discussed.
1610.03822
Victor Martin Lozano
Chiara Arina, Mikael Chala, Victor Martin-Lozano, Germano Nardini
Confronting SUSY models with LHC data via electroweakino production
33 pages, 10 figures, 3 tables
null
10.1007/JHEP12(2016)149
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate multi-lepton signals produced by ElectroWeakino (EWino) decays in the MSSM and the TMSSM scenarios with sfermions, gluinos and non Standard Model Higgses at the TeV scale, being the Bino electroweak-scale dark matter. We recast the present LHC constraints on EWinos for these models and we find that wide MSSM and TMSSM parameter regions prove to be allowed. We forecast the number of events expected in the signal regions of the experimental multi-lepton analyses in the next LHC runs. The correlations among these numbers will help to determine whether future deviations in multi-lepton data are ascribable to the EWinos, as well as the supersymmetric model they originate from.
[ { "created": "Wed, 12 Oct 2016 18:53:08 GMT", "version": "v1" } ]
2017-02-01
[ [ "Arina", "Chiara", "" ], [ "Chala", "Mikael", "" ], [ "Martin-Lozano", "Victor", "" ], [ "Nardini", "Germano", "" ] ]
We investigate multi-lepton signals produced by ElectroWeakino (EWino) decays in the MSSM and the TMSSM scenarios with sfermions, gluinos and non Standard Model Higgses at the TeV scale, being the Bino electroweak-scale dark matter. We recast the present LHC constraints on EWinos for these models and we find that wide MSSM and TMSSM parameter regions prove to be allowed. We forecast the number of events expected in the signal regions of the experimental multi-lepton analyses in the next LHC runs. The correlations among these numbers will help to determine whether future deviations in multi-lepton data are ascribable to the EWinos, as well as the supersymmetric model they originate from.
1012.3398
Alexander Kovner
Alex Kovner and Michael Lublinsky
Angular Correlations in Gluon Production at High Energy
12 pages
Phys.Rev.D83:034017,2011
10.1103/PhysRevD.83.034017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a general, model independent argument demonstrating that gluons produced in high energy hadronic collision are necessarily correlated in rapidity and also in the emission angle. The strength of the correlation depends on the process and on the structure/model of the colliding particles. In particular we argue that it is strongly affected (and underestimated) by factorized approximations frequently used to quantify the effect.
[ { "created": "Wed, 15 Dec 2010 17:47:10 GMT", "version": "v1" } ]
2011-02-22
[ [ "Kovner", "Alex", "" ], [ "Lublinsky", "Michael", "" ] ]
We present a general, model independent argument demonstrating that gluons produced in high energy hadronic collision are necessarily correlated in rapidity and also in the emission angle. The strength of the correlation depends on the process and on the structure/model of the colliding particles. In particular we argue that it is strongly affected (and underestimated) by factorized approximations frequently used to quantify the effect.
1901.05196
Zhi-Gang Wang
Zun-Yan Di, Zhi-Gang Wang
Analysis of the $D\bar{D}^*K$ system with QCD sum rules
9 pages, 4 figures
Adv.High Energy Phys. 2019 (2019) 8958079
10.1155/2019/8958079
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we construct the color singlet-singlet-singlet interpolating current with $I\left(J^P\right)=\frac{3}{2}\left(1^-\right)$ to study the $D\bar{D}^*K$ system through QCD sum rules approach. In calculations, we consider the contributions of the vacuum condensates up to dimension-16 and employ the formula $\mu=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}}$ to choose the optimal energy scale of the QCD spectral density. The numerical result $M_Z=4.71_{-0.11}^{+0.19}\,\rm{GeV}$ indicates that there exists a resonance state $Z$ lying above the $D\bar{D}^*K$ threshold to saturate the QCD sum rules. This resonance state $Z$ may be found by focusing on the channel $J/\psi \pi K$ of the decay $B\longrightarrow J/\psi \pi \pi K$ in the future.
[ { "created": "Wed, 16 Jan 2019 09:50:23 GMT", "version": "v1" }, { "created": "Thu, 28 Feb 2019 00:06:34 GMT", "version": "v2" } ]
2019-04-04
[ [ "Di", "Zun-Yan", "" ], [ "Wang", "Zhi-Gang", "" ] ]
In this article, we construct the color singlet-singlet-singlet interpolating current with $I\left(J^P\right)=\frac{3}{2}\left(1^-\right)$ to study the $D\bar{D}^*K$ system through QCD sum rules approach. In calculations, we consider the contributions of the vacuum condensates up to dimension-16 and employ the formula $\mu=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}}$ to choose the optimal energy scale of the QCD spectral density. The numerical result $M_Z=4.71_{-0.11}^{+0.19}\,\rm{GeV}$ indicates that there exists a resonance state $Z$ lying above the $D\bar{D}^*K$ threshold to saturate the QCD sum rules. This resonance state $Z$ may be found by focusing on the channel $J/\psi \pi K$ of the decay $B\longrightarrow J/\psi \pi \pi K$ in the future.
1501.00668
Hiroyuki Ishida
Naoyuki Haba, Hiroyuki Ishida, Tsuyoshi Nakaya, Yasuhiro Shimizu, and Ryo Takahashi
Search for new physics via photon polarization of $b \rightarrow s \gamma$
20 pages, 8 figures, v2:references added, v3:published version
null
10.1007/JHEP03(2015)160
SU-HET-01-2015, TU-987
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a discriminant analysis of new physics beyond the standard model through a detection of photon polarization in a radiative B meson decay. This analysis is investigated in SUSY SU(5) GUT with right-handed neutrino and left-right symmetric models. New physics search via CP asymmetry in the same process are also evaluated in each model for comparison. We show that new physics can be found via detecting the photon polarization in a parameter space of TeV energy scale.
[ { "created": "Sun, 4 Jan 2015 12:05:10 GMT", "version": "v1" }, { "created": "Tue, 20 Jan 2015 08:39:54 GMT", "version": "v2" }, { "created": "Sun, 5 Apr 2015 06:04:54 GMT", "version": "v3" } ]
2015-04-07
[ [ "Haba", "Naoyuki", "" ], [ "Ishida", "Hiroyuki", "" ], [ "Nakaya", "Tsuyoshi", "" ], [ "Shimizu", "Yasuhiro", "" ], [ "Takahashi", "Ryo", "" ] ]
We suggest a discriminant analysis of new physics beyond the standard model through a detection of photon polarization in a radiative B meson decay. This analysis is investigated in SUSY SU(5) GUT with right-handed neutrino and left-right symmetric models. New physics search via CP asymmetry in the same process are also evaluated in each model for comparison. We show that new physics can be found via detecting the photon polarization in a parameter space of TeV energy scale.
1411.3587
Claude Duhr
Claude Duhr, Thomas Gehrmann, Matthieu Jaquier
Two-loop splitting amplitudes and the single-real contribution to inclusive Higgs production at N3LO
71 pages
null
10.1007/JHEP02(2015)077
CP3-14-72, ZU-TH 38/14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional dimensional regularisation, we compute the two-loop splitting amplitudes for all simple collinear splitting processes, including subleading terms in the regularisation parameter. Our results are then applied to derive an analytical expression for the two-loop single-real contribution to inclusive Higgs boson production in gluon fusion to fourth order (N3LO) in perturbative QCD.
[ { "created": "Thu, 13 Nov 2014 15:50:45 GMT", "version": "v1" } ]
2015-06-23
[ [ "Duhr", "Claude", "" ], [ "Gehrmann", "Thomas", "" ], [ "Jaquier", "Matthieu", "" ] ]
The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional dimensional regularisation, we compute the two-loop splitting amplitudes for all simple collinear splitting processes, including subleading terms in the regularisation parameter. Our results are then applied to derive an analytical expression for the two-loop single-real contribution to inclusive Higgs boson production in gluon fusion to fourth order (N3LO) in perturbative QCD.
1812.01580
Gorazd Cvetic
Gorazd Cvetic
Renormalon-motivated evaluation of QCD observables
38 pages, 7 figures; v2: minor changes in the text and notations, version as it appears in Phys.Rev.D
Phys. Rev. D 99, 014028 (2019)
10.1103/PhysRevD.99.014028
USM-TH-358
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A method of evaluation of spacelike QCD observables ${\cal D}(Q^2)$ is developed, motivated by the renormalon structure of these quantities. A related auxiliary quantity ${\widetilde {\cal D}}(Q^2)$ is introduced, which is renomalization scale independent only at the one-loop level, and a large-$\beta_0$-type renormalon motivated ansatz is made for the Borel transform of this quantity. This leads to a `dressed' Borel transform of the considered observable ${\cal D}(Q^2)$. From there, a Neubert-type distribution is obtained for the observable. The described method is then applied to the massless Adler function and the related decay ratio of the $\tau$ lepton semihadronic decays. Comparisons are then made with an evaluation method at higher truncated orders, developed in our earlier works, which is a renormalization scale invariant extension of the diagonal Pad\'e approximants.
[ { "created": "Tue, 4 Dec 2018 18:37:07 GMT", "version": "v1" }, { "created": "Fri, 18 Jan 2019 13:14:42 GMT", "version": "v2" } ]
2019-01-23
[ [ "Cvetic", "Gorazd", "" ] ]
A method of evaluation of spacelike QCD observables ${\cal D}(Q^2)$ is developed, motivated by the renormalon structure of these quantities. A related auxiliary quantity ${\widetilde {\cal D}}(Q^2)$ is introduced, which is renomalization scale independent only at the one-loop level, and a large-$\beta_0$-type renormalon motivated ansatz is made for the Borel transform of this quantity. This leads to a `dressed' Borel transform of the considered observable ${\cal D}(Q^2)$. From there, a Neubert-type distribution is obtained for the observable. The described method is then applied to the massless Adler function and the related decay ratio of the $\tau$ lepton semihadronic decays. Comparisons are then made with an evaluation method at higher truncated orders, developed in our earlier works, which is a renormalization scale invariant extension of the diagonal Pad\'e approximants.
1008.0542
Simone Pacetti
Rinaldo Baldini Ferroli, Simone Pacetti, Adriano Zallo
No Sommerfeld resummation factor in e+e- -> ppbar ?
9 pages, 6 figures
null
10.1140/epja/i2012-12033-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Sommerfeld rescattering formula is compared to the e+e- -> ppbar BaBar data at threshold and above. While there is the expected Coulomb enhancement at threshold, two unexpected outcomes have been found: |G^p (4M_p^2)|= 1, like for a pointlike fermion, and moreover data show that the resummation factor in the Sommerfeld formula is not needed. Other e+e- -> baryon-antibaryon cross sections show a similar behavior near threshold.
[ { "created": "Tue, 3 Aug 2010 13:11:37 GMT", "version": "v1" } ]
2015-05-19
[ [ "Ferroli", "Rinaldo Baldini", "" ], [ "Pacetti", "Simone", "" ], [ "Zallo", "Adriano", "" ] ]
The Sommerfeld rescattering formula is compared to the e+e- -> ppbar BaBar data at threshold and above. While there is the expected Coulomb enhancement at threshold, two unexpected outcomes have been found: |G^p (4M_p^2)|= 1, like for a pointlike fermion, and moreover data show that the resummation factor in the Sommerfeld formula is not needed. Other e+e- -> baryon-antibaryon cross sections show a similar behavior near threshold.
2304.06736
Dharam Vir Ahluwalia
Dharam Vir Ahluwalia
Significance of classically forbidden regions for short baseline neutrino experiments
10 pages, 3 Figures
Europhysics Letters (EPL), Vol. 142, Issue 2 (2023) 22001 (An invited Perspective article.)
10.1209/0295-5075/acc88d
null
hep-ph nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classically forbidden regions ($\mathtt{CFRs}$) are common to both non-relativistic quantum mechanics, and to relativistic quantum field theory. It is known since 2001 that $\mathtt{CFR}$ contributes roughly sixteen percent of energy to the ground state of a simple harmonic oscillator (Adunas G. Z. et al., Gen. Relativ. Gravit., 33 (2001) 183). Similarly, quantum field theoretic arguments yield a non-zero amplitude for a massive particle to cross the light cone (that is, into the $\mathtt{CFR}$). The signs of these amplitudes are opposite for fermions and antifermions. This has given rise to an erroneous conclusion that amplitude to cross the lightcone is identically zero. This is true as long as a measurement does not reveal the considered object to be a particle or antiparticle. However, neutrino oscillation experiments do measure a neutrino $\nu$, or an antineutrino $\bar\nu$. Here we show that in the context of neutrino oscillations these observations have the potential to resolve various short baseline anomalies for a sufficiently light lowest mass eigenstate. In addition, we make a concrete prediction for the upcoming results to be announced later this year by JSNS$^2$.
[ { "created": "Thu, 13 Apr 2023 13:31:38 GMT", "version": "v1" } ]
2023-04-17
[ [ "Ahluwalia", "Dharam Vir", "" ] ]
Classically forbidden regions ($\mathtt{CFRs}$) are common to both non-relativistic quantum mechanics, and to relativistic quantum field theory. It is known since 2001 that $\mathtt{CFR}$ contributes roughly sixteen percent of energy to the ground state of a simple harmonic oscillator (Adunas G. Z. et al., Gen. Relativ. Gravit., 33 (2001) 183). Similarly, quantum field theoretic arguments yield a non-zero amplitude for a massive particle to cross the light cone (that is, into the $\mathtt{CFR}$). The signs of these amplitudes are opposite for fermions and antifermions. This has given rise to an erroneous conclusion that amplitude to cross the lightcone is identically zero. This is true as long as a measurement does not reveal the considered object to be a particle or antiparticle. However, neutrino oscillation experiments do measure a neutrino $\nu$, or an antineutrino $\bar\nu$. Here we show that in the context of neutrino oscillations these observations have the potential to resolve various short baseline anomalies for a sufficiently light lowest mass eigenstate. In addition, we make a concrete prediction for the upcoming results to be announced later this year by JSNS$^2$.
1711.07514
Timothy Raben
Federico Deganutti, David Gordo Gomez, Timothy Raben, Christophe Royon
Pomeron Physics at the LHC
11 pages, 9 figures, 1 table. ISMD-2017 proceedings, will be published on-line on the EPJ Web of Conferences; References added
null
10.1051/epjconf/201817206006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present current and ongoing research aimed at identifying Pomeron effects at the LHC in both the weak and strongly coupled regimes of QCD.
[ { "created": "Mon, 20 Nov 2017 19:43:38 GMT", "version": "v1" }, { "created": "Wed, 29 Nov 2017 16:17:46 GMT", "version": "v2" } ]
2018-03-14
[ [ "Deganutti", "Federico", "" ], [ "Gomez", "David Gordo", "" ], [ "Raben", "Timothy", "" ], [ "Royon", "Christophe", "" ] ]
We present current and ongoing research aimed at identifying Pomeron effects at the LHC in both the weak and strongly coupled regimes of QCD.
0905.4346
Brett D. Altschul
Brett Altschul
Bounding Isotropic Lorentz Violation Using Synchrotron Losses at LEP
8 pages
Phys. Rev. D 80, 091901(R) (2009)
10.1103/PhysRevD.80.091901
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Some deviations from special relativity--especially isotropic effects--are most efficiently constrained using particles with velocities very close to 1. While there are extremely tight bounds on some of the relevant parameters coming from astrophysical observations, many of these rely on our having an accurate understanding of the dynamics of high-energy sources. It is desirable to have reliable laboratory constraints on these same parameters. The fastest-moving particles in a laboratory were electrons and positrons at LEP. The energetics of the LEP beams were extremely well understood, and measurements of the synchrotron emission rate indicate that that any isotropic deviation of the speed of light from 1 must be smaller than 5 x 10^(-15).
[ { "created": "Wed, 27 May 2009 07:29:10 GMT", "version": "v1" }, { "created": "Tue, 10 Nov 2009 15:32:14 GMT", "version": "v2" } ]
2009-11-10
[ [ "Altschul", "Brett", "" ] ]
Some deviations from special relativity--especially isotropic effects--are most efficiently constrained using particles with velocities very close to 1. While there are extremely tight bounds on some of the relevant parameters coming from astrophysical observations, many of these rely on our having an accurate understanding of the dynamics of high-energy sources. It is desirable to have reliable laboratory constraints on these same parameters. The fastest-moving particles in a laboratory were electrons and positrons at LEP. The energetics of the LEP beams were extremely well understood, and measurements of the synchrotron emission rate indicate that that any isotropic deviation of the speed of light from 1 must be smaller than 5 x 10^(-15).
2202.03450
Jonathan Machado-Rodr\'iguez
J. Bonilla, I. Brivio, J. Machado-Rodr\'iguez, J. F. de Troc\'oniz
Nonresonant Searches for Axion-Like Particles in Vector Boson Scattering Processes at the LHC
27 pages, 11 figures, 6 tables. Version accepted for publication in JHEP
JHEP 06 (2022) 113
10.1007/JHEP06(2022)113
IFT-UAM/CSIC-22-7, VBSCAN-PUB-01-22
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new search for Axion-Like Particles (ALPs), targeting Vector Boson Scattering (VBS) processes at the LHC. We consider nonresonant ALP-mediated VBS, where the ALP participates as an off-shell mediator. This process occurs whenever the ALP is too light to be produced resonantly, and it takes advantage of the derivative nature of ALP interactions with the electroweak Standard Model bosons. We study the production of $ZZ$, $Z\gamma$, $W^\pm \gamma$, $W^\pm Z$ and $W^\pm W^\pm$ pairs with large diboson invariant masses in association with two jets. Working in a gauge-invariant framework, upper limits on ALP couplings to electroweak bosons are obtained from a reinterpretation of Run 2 public CMS VBS analyses. The constraints inferred on ALP couplings to $ZZ$, $Z\gamma$ and $W^\pm W^\pm$ pairs are very competitive for ALP masses up to 100 GeV. They have the advantage of being independent of the ALP coupling to gluons and of the ALP decay width. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMS.
[ { "created": "Mon, 7 Feb 2022 19:00:10 GMT", "version": "v1" }, { "created": "Wed, 18 May 2022 11:30:53 GMT", "version": "v2" } ]
2022-06-23
[ [ "Bonilla", "J.", "" ], [ "Brivio", "I.", "" ], [ "Machado-Rodríguez", "J.", "" ], [ "de Trocóniz", "J. F.", "" ] ]
We propose a new search for Axion-Like Particles (ALPs), targeting Vector Boson Scattering (VBS) processes at the LHC. We consider nonresonant ALP-mediated VBS, where the ALP participates as an off-shell mediator. This process occurs whenever the ALP is too light to be produced resonantly, and it takes advantage of the derivative nature of ALP interactions with the electroweak Standard Model bosons. We study the production of $ZZ$, $Z\gamma$, $W^\pm \gamma$, $W^\pm Z$ and $W^\pm W^\pm$ pairs with large diboson invariant masses in association with two jets. Working in a gauge-invariant framework, upper limits on ALP couplings to electroweak bosons are obtained from a reinterpretation of Run 2 public CMS VBS analyses. The constraints inferred on ALP couplings to $ZZ$, $Z\gamma$ and $W^\pm W^\pm$ pairs are very competitive for ALP masses up to 100 GeV. They have the advantage of being independent of the ALP coupling to gluons and of the ALP decay width. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMS.
hep-ph/9408330
null
Tiehui (Ted) Liu
The $D^0\bar{D}^0$ Mixing Search --- Current Status and Future Prospects
21 pages. Preprint HUTP-94/E021. To appear in Charm 2000 workshop proceedings, use Charm2000.sty, appended after text. 6 compressed figures
null
null
null
hep-ph
null
The search for $D^0\bar{D}^0$ mixing carries a large discovery potential for new physics since the $D^0\bar{D}^0$ mixing rate is expected to be very small in the Standard Model. The past decade has seen significant experimental progress in sensitivity, from 20\% down to 0.37\%. This paper discusses the techniques, current experimental status, and future prospects for the mixing search. Some new ideas, applicable to future mixing searches, are introduced. One of the new ideas is to use Singly Cabibbo Suppressed Decays (SCSD), such as $D^0 \to K+K-, \pi^+\pi^-$, to study mixing. A postscript version will be available through World-Wide-Web in http://w4.lns.cornell.edu/public/TALK/1994 soon.
[ { "created": "Sat, 20 Aug 1994 11:42:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tiehui", "", "", "Ted" ], [ "Liu", "", "" ] ]
The search for $D^0\bar{D}^0$ mixing carries a large discovery potential for new physics since the $D^0\bar{D}^0$ mixing rate is expected to be very small in the Standard Model. The past decade has seen significant experimental progress in sensitivity, from 20\% down to 0.37\%. This paper discusses the techniques, current experimental status, and future prospects for the mixing search. Some new ideas, applicable to future mixing searches, are introduced. One of the new ideas is to use Singly Cabibbo Suppressed Decays (SCSD), such as $D^0 \to K+K-, \pi^+\pi^-$, to study mixing. A postscript version will be available through World-Wide-Web in http://w4.lns.cornell.edu/public/TALK/1994 soon.
hep-ph/0012343
Takeo Matsushima
Takeo Matsushima
Scalar partner of $Z^0$-boson with larger mass value than $Z^0$-boson mass in Subquark model
21 pages, 2 figures
null
null
TMI-00-2
hep-ph
null
The subquark model previously proposed by us showes that the intermediate $Z^0$-boson is realized as the composite object and its scalar partner has the mass value larger than $Z^0$-boson mass, which is about 110 GeV.
[ { "created": "Wed, 27 Dec 2000 09:02:21 GMT", "version": "v1" } ]
2016-09-06
[ [ "Matsushima", "Takeo", "" ] ]
The subquark model previously proposed by us showes that the intermediate $Z^0$-boson is realized as the composite object and its scalar partner has the mass value larger than $Z^0$-boson mass, which is about 110 GeV.
1506.09018
Farrukh A. Chishtie
Farrukh Chishtie, T.G. Steele and D.G.C. McKeon
Renormalization Group Summation of Laplace QCD Sum Rules for Scalar Gluon Currents
Accepted Physics Letters B version, 17 pages, 7 figures in LaTeX2e format
Physics Letters B, Vol. 754, pp. 43-48, 2016
10.1016/j.physletb.2016.01.008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We employ renormalization group (RG) summation techniques to obtain portions of Laplace QCD sum rules for scalar gluon currents beyond the order to which they have been explicitly calculated. The first two of these sum rules are considered in some detail, and it is shown that they have significantly less dependence on the renormalization scale parameter $\mu^2$ once the RG summation is used to extend the perturbative results. Using the sum rules, we then compute the bound on the scalar glueball mass and demonstrate that the 3 and 4-Loop perturbative results form lower and upper bounds to their RG summed counterparts. We further demonstrate improved convergence of the RG summed expressions with respect to perturbative results.
[ { "created": "Tue, 30 Jun 2015 10:12:25 GMT", "version": "v1" }, { "created": "Sat, 9 Jan 2016 16:10:47 GMT", "version": "v2" } ]
2016-01-29
[ [ "Chishtie", "Farrukh", "" ], [ "Steele", "T. G.", "" ], [ "McKeon", "D. G. C.", "" ] ]
We employ renormalization group (RG) summation techniques to obtain portions of Laplace QCD sum rules for scalar gluon currents beyond the order to which they have been explicitly calculated. The first two of these sum rules are considered in some detail, and it is shown that they have significantly less dependence on the renormalization scale parameter $\mu^2$ once the RG summation is used to extend the perturbative results. Using the sum rules, we then compute the bound on the scalar glueball mass and demonstrate that the 3 and 4-Loop perturbative results form lower and upper bounds to their RG summed counterparts. We further demonstrate improved convergence of the RG summed expressions with respect to perturbative results.
1603.05978
Matthias Neubert
Martin Bauer (Univ. Heidelberg), Clara Hoerner (Univ. Mainz) and Matthias Neubert (MITP Mainz)
Diphoton Resonance from a Warped Extra Dimension
31 pages, 7 figures, 3 tables; v2: typos fixed and some references added; v3: missing color factor in t tbar rates included and numerical results updated, extended discussion of the Higgs portal, version published in JHEP
null
10.1007/JHEP07(2016)094
MITP/16-025
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton excess recently reported by ATLAS and CMS. A gauge-singlet bulk scalar with ${\cal O}(1)$ couplings to fermions is identified as the new resonance $S$, and the vector-like Kaluza-Klein excitations of the SM quarks and leptons mediate its loop-induced couplings to photons and gluons. The electroweak gauge symmetry almost unambiguously dictates the bulk matter content and hence the hierarchies of the $S\to \gamma\gamma$, $WW$, $ZZ$, $Z\gamma$, $t\bar t$ and dijet decay rates. We find that the $S\to Z\gamma$ decay mode is strongly suppressed, such that $\mbox{Br}(S\to Z\gamma)/\mbox{Br}(S\to\gamma\gamma)<0.1$. The hierarchy problem for the new scalar boson is solved in analogy with the Higgs boson by localizing it near the infrared brane. The infinite sums over the Kaluza-Klein towers of fermion states are finite and can be calculated in closed form with a remarkably simple result. Reproducing the observed $pp\to S\to\gamma\gamma$ signal requires Kaluza-Klein masses in the multi-TeV range, consistent with bounds from flavor physics and electroweak precision observables. Useful side products of our analysis, which can be adapted to almost any model for the diphoton resonance, are the calculation of the gluon-fusion production cross section $\sigma(pp\to S)$ at NNLO in QCD, an exact expression for the inclusive $S\to gg$ decay rate at N$^3$LO, a study of the $S\to t\bar t h$ three-body decay and a phenomenological analysis of portal couplings connecting $S$ with the Higgs field.
[ { "created": "Fri, 18 Mar 2016 20:00:03 GMT", "version": "v1" }, { "created": "Mon, 4 Apr 2016 17:04:28 GMT", "version": "v2" }, { "created": "Fri, 22 Jul 2016 17:19:48 GMT", "version": "v3" } ]
2016-08-24
[ [ "Bauer", "Martin", "", "Univ. Heidelberg" ], [ "Hoerner", "Clara", "", "Univ. Mainz" ], [ "Neubert", "Matthias", "", "MITP Mainz" ] ]
We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton excess recently reported by ATLAS and CMS. A gauge-singlet bulk scalar with ${\cal O}(1)$ couplings to fermions is identified as the new resonance $S$, and the vector-like Kaluza-Klein excitations of the SM quarks and leptons mediate its loop-induced couplings to photons and gluons. The electroweak gauge symmetry almost unambiguously dictates the bulk matter content and hence the hierarchies of the $S\to \gamma\gamma$, $WW$, $ZZ$, $Z\gamma$, $t\bar t$ and dijet decay rates. We find that the $S\to Z\gamma$ decay mode is strongly suppressed, such that $\mbox{Br}(S\to Z\gamma)/\mbox{Br}(S\to\gamma\gamma)<0.1$. The hierarchy problem for the new scalar boson is solved in analogy with the Higgs boson by localizing it near the infrared brane. The infinite sums over the Kaluza-Klein towers of fermion states are finite and can be calculated in closed form with a remarkably simple result. Reproducing the observed $pp\to S\to\gamma\gamma$ signal requires Kaluza-Klein masses in the multi-TeV range, consistent with bounds from flavor physics and electroweak precision observables. Useful side products of our analysis, which can be adapted to almost any model for the diphoton resonance, are the calculation of the gluon-fusion production cross section $\sigma(pp\to S)$ at NNLO in QCD, an exact expression for the inclusive $S\to gg$ decay rate at N$^3$LO, a study of the $S\to t\bar t h$ three-body decay and a phenomenological analysis of portal couplings connecting $S$ with the Higgs field.
1512.03073
Gyulnara Eyyubova
G. Eyyubova (SINP, Moscow & Prague, Tech. U.), I.P. Lokhtin (SINP, Moscow), A.V. Belyaev (SINP, Moscow), G. Ponimatkin, E. Yu. Pronina (SINP, Moscow)
Spectra and elliptic flow of charmed hadrons in HYDJET++ model
Conference: http://eps-hep2015.eu/
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy-flavour quarks are predominantly produced in hard scatterings on a short time-scale and traverse the medium interacting with its constituents, thus they are one of the effective probes of the transport properties of the medium formed in relativistic heavy ion collisions. On the other hand, the thermal production of heavy-flavour quarks in quark-gluon plasma (QGP) is itself of interest. In this report, the production and elliptic flow of the prompt charmed mesons $D^0$, $D^+$, $D^{*+}$ and $J/\psi$ in PbPb collisions at the center-of-mass energy 2.76 TeV per nucleon pair are described in the framework of two-component HYDJET++ model. The model combines thermal and pQCD production mechanisms. The spectra and elliptic flow of charmed mesons are presented, the results are compared with LHC data.
[ { "created": "Wed, 9 Dec 2015 21:01:45 GMT", "version": "v1" } ]
2015-12-11
[ [ "Eyyubova", "G.", "", "SINP, Moscow & Prague, Tech. U." ], [ "Lokhtin", "I. P.", "", "SINP,\n Moscow" ], [ "Belyaev", "A. V.", "", "SINP, Moscow" ], [ "Ponimatkin", "G.", "", "SINP,\n Moscow" ], [ "Pronina", "E. Yu.", "", "SINP,\n Moscow" ] ]
Heavy-flavour quarks are predominantly produced in hard scatterings on a short time-scale and traverse the medium interacting with its constituents, thus they are one of the effective probes of the transport properties of the medium formed in relativistic heavy ion collisions. On the other hand, the thermal production of heavy-flavour quarks in quark-gluon plasma (QGP) is itself of interest. In this report, the production and elliptic flow of the prompt charmed mesons $D^0$, $D^+$, $D^{*+}$ and $J/\psi$ in PbPb collisions at the center-of-mass energy 2.76 TeV per nucleon pair are described in the framework of two-component HYDJET++ model. The model combines thermal and pQCD production mechanisms. The spectra and elliptic flow of charmed mesons are presented, the results are compared with LHC data.
1911.03465
Yoshiki Yatagai
Nobuhito Maru and Yoshiki Yatagai
Improving Fermion Mass Hierarchy in Grand Gauge-Higgs Unification with Localized Gauge Kinetic Terms
arXiv admin note: substantial text overlap with arXiv:1903.08359 to appear in EPJC
null
10.1140/epjc/s10052-020-08485-8
OCU-PHYS: 513, NITEP: 39
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Grand gauge-Higgs unification of five dimensional SU(6) gauge theory on an orbifold S^1/Z_2 with localized gauge kinetic terms is discussed. The Standard model (SM) fermions on one of the boundaries and some massive bulk fermions coupling to the SM fermions on the boundary are introduced, so that they respect an SU(5) symmetry structure. The SM fermion masses including top quark are reproduced by mild tuning the bulk masses and parameters of the localized gauge kinetic terms. Gauge coupling universality is not guaranteed by the presence of the localized gauge kinetic terms and it severely constrains the Higgs vacuum expectation value. Higgs potential analysis shows that the electroweak symmetry breaking occurs by introducing additional bulk fermions in simplified representations.The localized gauge kinetic terms enhance the magnitude of the compactification scale, which helps Higgs boson mass large. Indeed the observed Higgs boson mass 125 GeV is obtained.
[ { "created": "Fri, 8 Nov 2019 11:53:36 GMT", "version": "v1" }, { "created": "Tue, 7 Jul 2020 16:44:00 GMT", "version": "v2" }, { "created": "Thu, 17 Sep 2020 08:05:39 GMT", "version": "v3" } ]
2020-10-28
[ [ "Maru", "Nobuhito", "" ], [ "Yatagai", "Yoshiki", "" ] ]
Grand gauge-Higgs unification of five dimensional SU(6) gauge theory on an orbifold S^1/Z_2 with localized gauge kinetic terms is discussed. The Standard model (SM) fermions on one of the boundaries and some massive bulk fermions coupling to the SM fermions on the boundary are introduced, so that they respect an SU(5) symmetry structure. The SM fermion masses including top quark are reproduced by mild tuning the bulk masses and parameters of the localized gauge kinetic terms. Gauge coupling universality is not guaranteed by the presence of the localized gauge kinetic terms and it severely constrains the Higgs vacuum expectation value. Higgs potential analysis shows that the electroweak symmetry breaking occurs by introducing additional bulk fermions in simplified representations.The localized gauge kinetic terms enhance the magnitude of the compactification scale, which helps Higgs boson mass large. Indeed the observed Higgs boson mass 125 GeV is obtained.
0801.0301
Erhan Iltan
E. O. Iltan
Lepton flavor violating $l_i\to l_j \gamma\gamma$ decays induced by scalar unparticle
10 pages, 5 figures, 1 table
Mod.Phys.Lett.A23:3331-3339,2008
10.1142/S021773230802714X
null
hep-ph
null
We study the radiative lepton flavor violating l_i -> l_j \gamma\gamma decays in the case that the lepton flavor violation is induced by the scalar unparticle mediation. We restrict the scaling dimension d_u and the scalar unparticle-photon-photon coupling by using the experimental upper limit of the branching ratio of the decay \mu -> e \gamma\gamma. Furthermore, we predict the BRs of the other radiative decays by using the restrictions we get. We observe that the measurements of upper limits of BRs of these decays ensure considerable information for testing the possible signals coming from unparticle physics
[ { "created": "Tue, 1 Jan 2008 15:47:47 GMT", "version": "v1" } ]
2009-02-11
[ [ "Iltan", "E. O.", "" ] ]
We study the radiative lepton flavor violating l_i -> l_j \gamma\gamma decays in the case that the lepton flavor violation is induced by the scalar unparticle mediation. We restrict the scaling dimension d_u and the scalar unparticle-photon-photon coupling by using the experimental upper limit of the branching ratio of the decay \mu -> e \gamma\gamma. Furthermore, we predict the BRs of the other radiative decays by using the restrictions we get. We observe that the measurements of upper limits of BRs of these decays ensure considerable information for testing the possible signals coming from unparticle physics
hep-ph/0404146
C. A. de S. Pires
C. A. de S. Pires
More on deviation from bi-maximal neutrino mixing
a scenario realizing our proposal is added, new references added, to be published in J.Phys.G
J.Phys. G30 (2004) B29-B34
10.1088/0954-3899/30/10/B01
null
hep-ph
null
We study the case of $U^T_l$ presenting the exact bi-maximal mixing form with $U_\nu$ inducing the deviation from the bi-maximal mixing in the final form of the Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing, $U_{PMNS}=U^T_l U_\nu$. We will show that such possibility will lead to a democratic texture for the charged lepton mass matrix and to a neutrino mass matrix with four null entries.
[ { "created": "Sat, 17 Apr 2004 20:42:33 GMT", "version": "v1" }, { "created": "Thu, 8 Jul 2004 20:41:40 GMT", "version": "v2" } ]
2009-11-10
[ [ "Pires", "C. A. de S.", "" ] ]
We study the case of $U^T_l$ presenting the exact bi-maximal mixing form with $U_\nu$ inducing the deviation from the bi-maximal mixing in the final form of the Pontecorvo-Maki-Nakagawa-Sakata neutrino mixing, $U_{PMNS}=U^T_l U_\nu$. We will show that such possibility will lead to a democratic texture for the charged lepton mass matrix and to a neutrino mass matrix with four null entries.
1209.5585
Yutaka Tobita
Kenzo Ishikawa and Yutaka Tobita
A new method for measuring the absolute neutrino mass
36 pages, 12 figures; title changed
null
null
EPHOU-12-003
hep-ph hep-ex quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The probability of the event that a neutrino produced in pion decay is detected in the intermediate $T$ shorter than the life-time $\tau_{\pi}$, $T \leq \tau_{\pi}$, is sensitive to the absolute mass of the neutrino. With a newly formulated S-matrix $S[T]$ that satisfies the boundary conditions of the experiments at a finite $T$, the rate of the event is computed as $\Gamma_0+\tilde{g}(\omega_{\nu}, {T};\tau_{\pi}) \tilde \Gamma_{1} $, where $\tilde{g}(\omega_{\nu},{T};\tau_{\pi})$ depends weakly on $\tau_{\pi}$ and $\omega_{\nu}={m_{\nu}^2c^4}/{(2E_{\nu}\hbar)}$, $c$ is the speed of light. $\Gamma_0$ is the standard one and the correction, $\tilde{g}(\omega_{\nu}, {T};\tau_{\pi}) \tilde \Gamma_{1} $, reflects relativistic invariance and is rigorously computed via the light-cone singularity of the system and reveals the diffraction pattern of a single quantum. The formula explains unsolved anomalies of neutrino experiments and indicates the heavy neutrino mass, $0.098 \pm 0.022$ or $0.083 \pm 0.026$ {eV}/ $c^2$ for normal or inverted mass hierarchies, respectively.
[ { "created": "Tue, 25 Sep 2012 11:35:24 GMT", "version": "v1" }, { "created": "Wed, 13 Mar 2013 08:39:53 GMT", "version": "v2" }, { "created": "Thu, 9 May 2013 13:47:37 GMT", "version": "v3" }, { "created": "Wed, 27 Nov 2013 10:08:03 GMT", "version": "v4" } ]
2013-11-28
[ [ "Ishikawa", "Kenzo", "" ], [ "Tobita", "Yutaka", "" ] ]
The probability of the event that a neutrino produced in pion decay is detected in the intermediate $T$ shorter than the life-time $\tau_{\pi}$, $T \leq \tau_{\pi}$, is sensitive to the absolute mass of the neutrino. With a newly formulated S-matrix $S[T]$ that satisfies the boundary conditions of the experiments at a finite $T$, the rate of the event is computed as $\Gamma_0+\tilde{g}(\omega_{\nu}, {T};\tau_{\pi}) \tilde \Gamma_{1} $, where $\tilde{g}(\omega_{\nu},{T};\tau_{\pi})$ depends weakly on $\tau_{\pi}$ and $\omega_{\nu}={m_{\nu}^2c^4}/{(2E_{\nu}\hbar)}$, $c$ is the speed of light. $\Gamma_0$ is the standard one and the correction, $\tilde{g}(\omega_{\nu}, {T};\tau_{\pi}) \tilde \Gamma_{1} $, reflects relativistic invariance and is rigorously computed via the light-cone singularity of the system and reveals the diffraction pattern of a single quantum. The formula explains unsolved anomalies of neutrino experiments and indicates the heavy neutrino mass, $0.098 \pm 0.022$ or $0.083 \pm 0.026$ {eV}/ $c^2$ for normal or inverted mass hierarchies, respectively.
2212.09054
Ru-Xuan Wang
Ru-Xuan Wang, Mao-Zhi Yang
Branching ratio and $CP$ violation of $B\to K\pi$ decays in a modified perturbative QCD approach
19 pages, 2 figures, version to appear in Phys. Rev. D
null
10.1103/PhysRevD.108.013003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the branching ratio and $CP$ violations for $B\to K\pi$ decays in a modified perturbative QCD approach based on $k_{T}$ factorization. The resummation effect of the transverse momentum regulates the endpoint singularity. Using the $B$ meson wave function that is obtained in the relativistic potential model, soft contribution cannot be suppressed effectively by Sudakov factor. Soft scale cutoff and soft $BK$, $B\pi$ and $K\pi$ form factors have to be introduced. The most important next-to-leading-order contributions from the vertex corrections, the quark loops, and the magnetic penguins are also considered. In addition, the contribution of the color-octet hadronic matrix element is included which is essentially of long-distance dynamics. Our predictions for branching ratios and $CP$ violations are in good agreement with the experimental data. Especially the theoretical result of dramatic difference between the $CP$ violations of $B^+\to K^+\pi^0$ and $B^0\to K^+\pi^-$ is consistent with experimental measurement, therefore the $K\pi$ puzzle in $B$ decays can be resolved in our way of the modified perturbative QCD approach.
[ { "created": "Sun, 18 Dec 2022 10:06:09 GMT", "version": "v1" }, { "created": "Thu, 29 Jun 2023 15:34:34 GMT", "version": "v2" } ]
2023-07-26
[ [ "Wang", "Ru-Xuan", "" ], [ "Yang", "Mao-Zhi", "" ] ]
We calculate the branching ratio and $CP$ violations for $B\to K\pi$ decays in a modified perturbative QCD approach based on $k_{T}$ factorization. The resummation effect of the transverse momentum regulates the endpoint singularity. Using the $B$ meson wave function that is obtained in the relativistic potential model, soft contribution cannot be suppressed effectively by Sudakov factor. Soft scale cutoff and soft $BK$, $B\pi$ and $K\pi$ form factors have to be introduced. The most important next-to-leading-order contributions from the vertex corrections, the quark loops, and the magnetic penguins are also considered. In addition, the contribution of the color-octet hadronic matrix element is included which is essentially of long-distance dynamics. Our predictions for branching ratios and $CP$ violations are in good agreement with the experimental data. Especially the theoretical result of dramatic difference between the $CP$ violations of $B^+\to K^+\pi^0$ and $B^0\to K^+\pi^-$ is consistent with experimental measurement, therefore the $K\pi$ puzzle in $B$ decays can be resolved in our way of the modified perturbative QCD approach.
1206.4100
Jonathan Kozaczuk
Jonathan Kozaczuk, Stefano Profumo, Michael J. Ramsey-Musolf, Carroll L. Wainwright
Supersymmetric Electroweak Baryogenesis Via Resonant Sfermion Sources
35 pages, 9 figures; v2: several revisions, but conclusions unchanged. Matches version published in PRD
Phys. Rev. D. 86, (2012) 096001
10.1103/PhysRevD.86.096001
NPAC 12-09
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the baryon asymmetry produced at the electroweak phase transition by quasi-degenerate third generation sfermions in the minimal supersymmetric extension of the Standard Model. We evaluate constraints from Higgs searches, from collider searches for supersymmetric particles, and from null searches for the permanent electric dipole moment (EDM) of the electron, of the neutron and of atoms. We find that resonant sfermion sources can in principle provide a large enough baryon asymmetry in various corners of the sfermion parameter space, and we focus, in particular, on the case of large $\tan\beta$, where third-generation down-type (s)fermions become relevant. We show that in the case of stop and sbottom sources, the viable parameter space is ruled out by constraints from the non-observation of the Mercury EDM. We introduce a new class of CP violating sources, quasi-degenerate staus, that escapes current EDM constraints while providing large enough net chiral currents to achieve successful "slepton-mediated" electroweak baryogenesis.
[ { "created": "Tue, 19 Jun 2012 00:28:37 GMT", "version": "v1" }, { "created": "Thu, 15 Nov 2012 20:45:31 GMT", "version": "v2" } ]
2013-05-30
[ [ "Kozaczuk", "Jonathan", "" ], [ "Profumo", "Stefano", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Wainwright", "Carroll L.", "" ] ]
We calculate the baryon asymmetry produced at the electroweak phase transition by quasi-degenerate third generation sfermions in the minimal supersymmetric extension of the Standard Model. We evaluate constraints from Higgs searches, from collider searches for supersymmetric particles, and from null searches for the permanent electric dipole moment (EDM) of the electron, of the neutron and of atoms. We find that resonant sfermion sources can in principle provide a large enough baryon asymmetry in various corners of the sfermion parameter space, and we focus, in particular, on the case of large $\tan\beta$, where third-generation down-type (s)fermions become relevant. We show that in the case of stop and sbottom sources, the viable parameter space is ruled out by constraints from the non-observation of the Mercury EDM. We introduce a new class of CP violating sources, quasi-degenerate staus, that escapes current EDM constraints while providing large enough net chiral currents to achieve successful "slepton-mediated" electroweak baryogenesis.
hep-ph/0412157
Philip G. Ratcliffe
Philip G. Ratcliffe
Transversity K Factors for Drell-Yan
8 pages, 4 figures (eps and feynmp); uses standard LaTeX/MiKTeX packages [svjour.cls, amsmath, bbm, feynmp, graphicx, maybemath, natbib, psfrag, slashed] some homespun packages (included in the zip file); discussion augmented, 1 figure removed; resubmitted to Eur. Phys. J. section C
Eur.Phys.J.C41:319-325,2005
10.1140/epjc/s2005-02204-3
null
hep-ph
null
The question of the K factor in transversely polarised Drell-Yan (DY) processes is examined. The transverse-spin case is peculiar for the absence of a reference point in deeply inelastic scattering (DIS). Therefore, in order to study more fully the possible effects of higher-order corrections on DY asymmetries, a DIS definition for transversity is devised using a hypothetical scalar (Higgs-like) vertex. The results show that some care may be required in interpreting experimentally extracted partonic transversity, in particular when comparing with model calculations or predictions.
[ { "created": "Mon, 13 Dec 2004 17:33:49 GMT", "version": "v1" }, { "created": "Tue, 15 Mar 2005 01:56:35 GMT", "version": "v2" } ]
2011-09-13
[ [ "Ratcliffe", "Philip G.", "" ] ]
The question of the K factor in transversely polarised Drell-Yan (DY) processes is examined. The transverse-spin case is peculiar for the absence of a reference point in deeply inelastic scattering (DIS). Therefore, in order to study more fully the possible effects of higher-order corrections on DY asymmetries, a DIS definition for transversity is devised using a hypothetical scalar (Higgs-like) vertex. The results show that some care may be required in interpreting experimentally extracted partonic transversity, in particular when comparing with model calculations or predictions.
hep-ph/9810512
Andrzej Czarnecki
Andrzej Czarnecki and William J. Marciano
Lepton anomalous magnetic moments - a theory update
8 pages; invited talk at the 5th International Workshop on Tau Lepton Physics (Tau'98), September 1998, Santander, Spain
Nucl.Phys.Proc.Suppl. 76 (1999) 245-252
10.1016/S0920-5632(99)00474-0
BNL-HET-98/43
hep-ph
null
Standard Model contributions to the electron, muon, and tau lepton anomalous magnetic moments, a_l=(g_l-2)/2, are reviewed and updated. The fine structure constant is obtained from the electron g_e-2 and used to refine the QED contribution to the muon g_mu-2. Recent advances in electroweak and hadronic effects on g_mu-2 are summarized. Examples of ``New Physics'' probed by the a_mu Brookhaven experiment E821 are outlined. The prediction for a_tau is also given.
[ { "created": "Wed, 28 Oct 1998 20:58:26 GMT", "version": "v1" } ]
2009-10-31
[ [ "Czarnecki", "Andrzej", "" ], [ "Marciano", "William J.", "" ] ]
Standard Model contributions to the electron, muon, and tau lepton anomalous magnetic moments, a_l=(g_l-2)/2, are reviewed and updated. The fine structure constant is obtained from the electron g_e-2 and used to refine the QED contribution to the muon g_mu-2. Recent advances in electroweak and hadronic effects on g_mu-2 are summarized. Examples of ``New Physics'' probed by the a_mu Brookhaven experiment E821 are outlined. The prediction for a_tau is also given.
1301.4930
Kim Maltman
P.A. Boyle, L. Del Debbio, N. Garron, R.J. Hudspith, E. Kerrane, K. Maltman and J.M. Zanotti
New results from the lattice on the theoretical inputs to the hadronic tau determination of V_us
8 pages, 5 figures. Prepared for the proceedings of the 12th International Workshop on Tau Lepton Physics, Sep. 17-21, 2012, Nagoya, Japan and the 10th International Conference on Confinement and the Hadron Spectrum, Oct. 6-13, 2012, Garching/Munich, Germany
null
null
Adelaide preprint number ADP-13-03/T823
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent sum rule determinations of |V_us|, employing flavor-breaking combinations of hadronic tau decay data, are significantly lower than either expectations based on 3-family unitarity or determinations from K_ell3 and Gamma[K_mu2]/Gamma[pi_mu2]. We use lattice data to investigate the accuracy/reliability of the OPE representation of the flavor-breaking correlator combination entering the tau decay analyses. The behavior of an alternate correlator combination, constructed to reduce problems associated with the slow convergence of the D = 2 OPE series, and entering an alternate sum rule requiring both electroproduction cross-section and hadronic tau decay data, is also investigated. Preliminary updates of both analyses, with the lessons learned from the lattice data in mind, are also presented.
[ { "created": "Mon, 21 Jan 2013 17:24:14 GMT", "version": "v1" } ]
2013-01-22
[ [ "Boyle", "P. A.", "" ], [ "Del Debbio", "L.", "" ], [ "Garron", "N.", "" ], [ "Hudspith", "R. J.", "" ], [ "Kerrane", "E.", "" ], [ "Maltman", "K.", "" ], [ "Zanotti", "J. M.", "" ] ]
Recent sum rule determinations of |V_us|, employing flavor-breaking combinations of hadronic tau decay data, are significantly lower than either expectations based on 3-family unitarity or determinations from K_ell3 and Gamma[K_mu2]/Gamma[pi_mu2]. We use lattice data to investigate the accuracy/reliability of the OPE representation of the flavor-breaking correlator combination entering the tau decay analyses. The behavior of an alternate correlator combination, constructed to reduce problems associated with the slow convergence of the D = 2 OPE series, and entering an alternate sum rule requiring both electroproduction cross-section and hadronic tau decay data, is also investigated. Preliminary updates of both analyses, with the lessons learned from the lattice data in mind, are also presented.
hep-ph/9903295
Dirk Graudenz
Dirk Graudenz (PSI)
Jets and fragmentation
8 pages (Latex). Contribution to the Durham workshop on HERA physics 1998
J.Phys.G25:1289-1295,1999
10.1088/0954-3899/25/7/304
PSI-PR/98-29
hep-ph
null
I review the status of next-to-leading-order calculations for hadronic final states in deeply-inelastic lepton--nucleon scattering. In more detail, I focus on calculations of (2+1)-jet-type cross sections, describe recent progress in extending the perturbative description into the transition region between deeply inelastic scattering and photoproduction, and study the validity of the fragmentation function picture for one-particle-inclusive cross sections at small Q^2 and small x_p.
[ { "created": "Tue, 9 Mar 1999 11:18:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Graudenz", "Dirk", "", "PSI" ] ]
I review the status of next-to-leading-order calculations for hadronic final states in deeply-inelastic lepton--nucleon scattering. In more detail, I focus on calculations of (2+1)-jet-type cross sections, describe recent progress in extending the perturbative description into the transition region between deeply inelastic scattering and photoproduction, and study the validity of the fragmentation function picture for one-particle-inclusive cross sections at small Q^2 and small x_p.
hep-ph/9509330
Kyuzo Teshima
K.Tesima
Multiplicity and Event Shape in the Perturbative QCD
Invited talk at the 3rd Workshop on TRISTAN Physics at High Luminosities (October 1994) (Latex file)
null
null
OCHA-PP-64
hep-ph
null
The multiple hadroproduction in the perturbative QCD is briefly reviewed. There are a number of quantities which can be analysed with the use of the high-luminosity TRISTAN data. The analysis will contribute to clarifying some unsolved questions, and to the deeper understanding of the jet physics.
[ { "created": "Tue, 19 Sep 1995 13:03:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tesima", "K.", "" ] ]
The multiple hadroproduction in the perturbative QCD is briefly reviewed. There are a number of quantities which can be analysed with the use of the high-luminosity TRISTAN data. The analysis will contribute to clarifying some unsolved questions, and to the deeper understanding of the jet physics.
hep-ph/0204159
Harald Appelshauser
Harald Appelsh\"auser (Physikalisches Institut Universit\"at Heidelberg)
Pion Interferometry: Recent results from SPS
Invited talk at the International Workshop XXX on Gross Properties of Nuclei and Nuclear Excitations - Ultrarelativistic Heavy-Ion Collisions, Jan. 13-19, 2002, Hirschegg, Austria. 11 pages, 8 figures
null
null
null
hep-ph
null
Recent results from the CERES experiment at the SPS are reviewed. Emphasis is put on the centrality and beam energy dependence, and the results are put into perspective with findings at lower and higher beam energies. The rather weak beam energy dependence of the HBT radii maybe understood in terms of a transition from baryon to pion dominated freeze-out. The observed short lifetimes end emission durations are presently in contradiction to results from model calculations.
[ { "created": "Sun, 14 Apr 2002 14:05:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Appelshäuser", "Harald", "", "Physikalisches Institut Universität\n Heidelberg" ] ]
Recent results from the CERES experiment at the SPS are reviewed. Emphasis is put on the centrality and beam energy dependence, and the results are put into perspective with findings at lower and higher beam energies. The rather weak beam energy dependence of the HBT radii maybe understood in terms of a transition from baryon to pion dominated freeze-out. The observed short lifetimes end emission durations are presently in contradiction to results from model calculations.
1410.2983
Schoeffel Laurent
Mateusz Dyndal, Laurent Schoeffel
The role of finite-size effects on the spectrum of equivalent photons in proton-proton collisions at the LHC
14 pages, 7 figures, 1 table, submitted to Phys. Lett. B
null
10.1016/j.physletb.2014.12.019
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Photon-photon interactions represent an important class of physics processes at the LHC, where quasi-real photons are emitted by both colliding protons. These reactions can result in the exclusive production of a final state $X$, $p+p \rightarrow p+p+X$. When computing such cross sections, it has already been shown that finite size effects of colliding protons are important to consider for a realistic estimate of the cross sections. These first results have been essential in understanding the physics case of heavy-ion collisions in the low invariant mass range, where heavy ions collide to form an exclusive final state like a $J/\Psi$ vector meson. In this paper, our purpose is to present some calculations that are valid also for the exclusive production of high masses final states in proton-proton collisions, like the production of a pair of $W$ bosons or the Higgs boson. Therefore, we propose a complete treatment of the finite size effects of incident protons irrespective of the mass range explored in the collision. Our expectations are shown to be in very good agreement with existing experimental data obtained at the LHC.
[ { "created": "Sat, 11 Oct 2014 11:05:26 GMT", "version": "v1" }, { "created": "Thu, 16 Oct 2014 13:20:45 GMT", "version": "v2" }, { "created": "Mon, 27 Oct 2014 15:09:34 GMT", "version": "v3" }, { "created": "Mon, 24 Nov 2014 20:32:52 GMT", "version": "v4" }, { "created": "Tue, 9 Dec 2014 06:12:25 GMT", "version": "v5" } ]
2018-05-09
[ [ "Dyndal", "Mateusz", "" ], [ "Schoeffel", "Laurent", "" ] ]
Photon-photon interactions represent an important class of physics processes at the LHC, where quasi-real photons are emitted by both colliding protons. These reactions can result in the exclusive production of a final state $X$, $p+p \rightarrow p+p+X$. When computing such cross sections, it has already been shown that finite size effects of colliding protons are important to consider for a realistic estimate of the cross sections. These first results have been essential in understanding the physics case of heavy-ion collisions in the low invariant mass range, where heavy ions collide to form an exclusive final state like a $J/\Psi$ vector meson. In this paper, our purpose is to present some calculations that are valid also for the exclusive production of high masses final states in proton-proton collisions, like the production of a pair of $W$ bosons or the Higgs boson. Therefore, we propose a complete treatment of the finite size effects of incident protons irrespective of the mass range explored in the collision. Our expectations are shown to be in very good agreement with existing experimental data obtained at the LHC.
hep-ph/9507278
Tord Riemann
Arif Akhundov, Dima Bardin, Lida Kalinovskaya and Tord Riemann
Leptonic QED Corrections to the process $ep \longrightarrow eX$ in Jaquet-Blondel variables
9 pages, 1 figure, 1 table; Corrected Eq. (17) in the paper published in Phys. Lett. B301: 447-453, 1993, the numerics are unaffected by this misprint
Phys.Lett.B301:447-453,1993
10.1016/0370-2693(93)91177-O
DESY 92-175
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For the study of deep inelastic scattering at HERA, the use of Jaquet-Blondel variables is advantageous in several respects. We calculate the complete leptonic ${\cal O}(\alpha)$ QED corrections for the reaction $ep \to eX$ in these variables. All but one phase space integrations are performed analytically. After exponentiation of soft photon corrections, an accuracy of at least 1% is matched. Numerical results are presented and compared to estimates based on the leading logarithmic approximation. Equation (17) is corrected in accordance with equation (7.44) of DESY 94--115. The misprint did not influence the numerics.
[ { "created": "Tue, 11 Jul 1995 10:54:49 GMT", "version": "v1" }, { "created": "Thu, 10 Jul 2008 12:07:06 GMT", "version": "v2" } ]
2009-10-28
[ [ "Akhundov", "Arif", "" ], [ "Bardin", "Dima", "" ], [ "Kalinovskaya", "Lida", "" ], [ "Riemann", "Tord", "" ] ]
For the study of deep inelastic scattering at HERA, the use of Jaquet-Blondel variables is advantageous in several respects. We calculate the complete leptonic ${\cal O}(\alpha)$ QED corrections for the reaction $ep \to eX$ in these variables. All but one phase space integrations are performed analytically. After exponentiation of soft photon corrections, an accuracy of at least 1% is matched. Numerical results are presented and compared to estimates based on the leading logarithmic approximation. Equation (17) is corrected in accordance with equation (7.44) of DESY 94--115. The misprint did not influence the numerics.
hep-ph/0002103
Stefano Moretti
S. Moretti (RAL)
Six-quark decays of off-shell WW pairs via parton-level QCD in electron-positron annihilations
33 pages, latex, 12 figures
Eur.Phys.J.C16:115-130,2000
10.1007/s100520050008
RAL-TR-99-017
hep-ph
null
We study the decays into six quarks of off-shell pairs of W bosons produced in electron-positron annihilations, through the O(as^2) order in the strong coupling constant. We give explicit helicity amplitude formulae. We present numerical results in the context of phenomenological analyses of relevance at LEP2 and future Linear Colliders: such as MW determinations, New Physics and Higgs searches.
[ { "created": "Wed, 9 Feb 2000 16:14:21 GMT", "version": "v1" } ]
2011-09-13
[ [ "Moretti", "S.", "", "RAL" ] ]
We study the decays into six quarks of off-shell pairs of W bosons produced in electron-positron annihilations, through the O(as^2) order in the strong coupling constant. We give explicit helicity amplitude formulae. We present numerical results in the context of phenomenological analyses of relevance at LEP2 and future Linear Colliders: such as MW determinations, New Physics and Higgs searches.
1601.06665
Christian Weiss
W. Cosyn, V. Guzey, M. Sargsian, M. Strikman, C. Weiss
Electron-deuteron DIS with spectator tagging at EIC: Development of theoretical framework
7 pages, 3 figures. Proceedings of 6th International Conference on Physics Opportunities at an Electron-Ion Collider (POETIC6), Palaiseau, France, 7-11 September 2015
null
10.1051/epjconf/201611201022
JLAB-THY-16-2201
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An Electron-Ion Collider (EIC) would enable next-generation measurements of deep-inelastic scattering (DIS) on the deuteron with detection of a forward-moving nucleon (p, n) and measurement of its recoil momentum ("spectator tagging"). Such experiments offer full control of the nuclear configuration during the high-energy process and can be used for precision studies of the neutron's partonic structure and its spin dependence, nuclear modifications of partonic structure, and nuclear shadowing at small x. We review the theoretical description of spectator tagging at EIC energies (light-front nuclear structure, on-shell extrapolation in the recoil nucleon momentum, final-state interactions, diffractive effects at small x) and report about on-going developments.
[ { "created": "Mon, 25 Jan 2016 16:45:18 GMT", "version": "v1" } ]
2016-04-20
[ [ "Cosyn", "W.", "" ], [ "Guzey", "V.", "" ], [ "Sargsian", "M.", "" ], [ "Strikman", "M.", "" ], [ "Weiss", "C.", "" ] ]
An Electron-Ion Collider (EIC) would enable next-generation measurements of deep-inelastic scattering (DIS) on the deuteron with detection of a forward-moving nucleon (p, n) and measurement of its recoil momentum ("spectator tagging"). Such experiments offer full control of the nuclear configuration during the high-energy process and can be used for precision studies of the neutron's partonic structure and its spin dependence, nuclear modifications of partonic structure, and nuclear shadowing at small x. We review the theoretical description of spectator tagging at EIC energies (light-front nuclear structure, on-shell extrapolation in the recoil nucleon momentum, final-state interactions, diffractive effects at small x) and report about on-going developments.
hep-ph/9805285
null
C.P. Burgess, A. de la Macorra, I. Maksymyk and F. Quevedo
Constant versus Field Dependent Gauge Couplings in Supersymmetric Theories
Talk at PAST 97, Trieste, 10 pages, latex, sprocl.sty
null
null
IFUNAM FT98-4
hep-ph hep-th
null
We briefly discuss the differences between considering the gauge coupling as a constant or as a field, the dilaton, in N=1 supersymmetric theories. We emphasize the differences regarding supersymmetry breaking. Recent developments on the nonperturbative dynamics of these theories provide new ideas on the induced dilaton potential and its stabilization.
[ { "created": "Mon, 11 May 1998 18:22:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Burgess", "C. P.", "" ], [ "de la Macorra", "A.", "" ], [ "Maksymyk", "I.", "" ], [ "Quevedo", "F.", "" ] ]
We briefly discuss the differences between considering the gauge coupling as a constant or as a field, the dilaton, in N=1 supersymmetric theories. We emphasize the differences regarding supersymmetry breaking. Recent developments on the nonperturbative dynamics of these theories provide new ideas on the induced dilaton potential and its stabilization.
hep-ph/0612265
Magno Machado
V.P. Goncalves, M.V.T. Machado
Diffractive photoproduction of heavy quarks in hadronic collisions
4 pages, 2 figures, 1 table. Version to be published in Physical Review D
Phys.Rev.D75:031502,2007
10.1103/PhysRevD.75.031502
null
hep-ph
null
In this letter we study the diffractive photoproduction of heavy quarks in hadronic (pp/pA/AA) interactions for Tevatron and LHC energies. The integrated cross section and rapidity distribution for the process h_1 h_2 --> h_1 h_2 QQBAR (h_i = p,A and Q = c,b) are estimated using the Color Glass Condensate (CGC) formalism. Our results indicate that this production channel has larger cross sections than the competing reactions of double diffractive production and coherent AA reactions initiated by two-photon collisions.
[ { "created": "Wed, 20 Dec 2006 18:56:10 GMT", "version": "v1" }, { "created": "Wed, 31 Jan 2007 15:54:20 GMT", "version": "v2" } ]
2008-11-26
[ [ "Goncalves", "V. P.", "" ], [ "Machado", "M. V. T.", "" ] ]
In this letter we study the diffractive photoproduction of heavy quarks in hadronic (pp/pA/AA) interactions for Tevatron and LHC energies. The integrated cross section and rapidity distribution for the process h_1 h_2 --> h_1 h_2 QQBAR (h_i = p,A and Q = c,b) are estimated using the Color Glass Condensate (CGC) formalism. Our results indicate that this production channel has larger cross sections than the competing reactions of double diffractive production and coherent AA reactions initiated by two-photon collisions.
hep-ph/0107072
Alejandro Ayala
A. Ayala (ICN-Unam), J. Besprosvany (IF-Unam), G. Pallares (ICN-Unam) and G. Piccinelli (CTA-Unam)
Axially asymmetric fermion scattering off electroweak phase transition bubble walls with hypermagnetic fields
8 pages, 2 Encapsulated Postscript figures, uses ReVTeX and epsfig.sty, expanded discussion, version to appear in Phys. Rev. D
Phys.Rev. D64 (2001) 123529
10.1103/PhysRevD.64.123529
ICN-UNAM-14-01
hep-ph astro-ph
null
We show that in the presence of large scale primordial hypermagnetic fields, it is possible to generate an axial asymmetry for a first order electroweak phase transition. This happens during the reflection and transmission of fermions off the true vacuum bubbles, due to the chiral nature of the fermion coupling with the background field in the symmetric phase. We derive and solve the Dirac equation for such fermions and compute the reflection and transmission coefficients for the case when these fermions move from the symmetric to the symmetry broken phase. We also comment on the possible implications of such axial charge segregation processes for baryon number generation.
[ { "created": "Fri, 6 Jul 2001 17:51:36 GMT", "version": "v1" }, { "created": "Sat, 22 Sep 2001 00:42:57 GMT", "version": "v2" } ]
2009-11-07
[ [ "Ayala", "A.", "", "ICN-Unam" ], [ "Besprosvany", "J.", "", "IF-Unam" ], [ "Pallares", "G.", "", "ICN-Unam" ], [ "Piccinelli", "G.", "", "CTA-Unam" ] ]
We show that in the presence of large scale primordial hypermagnetic fields, it is possible to generate an axial asymmetry for a first order electroweak phase transition. This happens during the reflection and transmission of fermions off the true vacuum bubbles, due to the chiral nature of the fermion coupling with the background field in the symmetric phase. We derive and solve the Dirac equation for such fermions and compute the reflection and transmission coefficients for the case when these fermions move from the symmetric to the symmetry broken phase. We also comment on the possible implications of such axial charge segregation processes for baryon number generation.
hep-ph/9702428
Subhendra Mohanty
Subhendra Mohanty
Covariant treatment of neutrino oscillations
New sections added on Wave-packets analysis and EPR oscillations
null
null
null
hep-ph
null
We perform a covariant wavepacket analysis of neutrino oscillations taking into account the lifetime of the neutrino production process . We find that flavour oscillations in space are washed out when the neutrinos are produced from long lived resonances - and what may be observed in appearance/disappearance experiments is a uniform conversion probability independent of distance. The lifetime of the resonance which produces the neutrinos acts as the the effective baseline of the experiment. For this reason the LSND experiment where neutrinos are produced from muon decay has two orders of magnitude more sensitivity to neutrino mass square difference than other experiments where the neutrinos are produced from pion or kaon decays.We also show that there are no EPR type oscillations of the secondary decay particles.
[ { "created": "Wed, 26 Feb 1997 08:40:54 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 1997 09:35:03 GMT", "version": "v2" } ]
2016-09-06
[ [ "Mohanty", "Subhendra", "" ] ]
We perform a covariant wavepacket analysis of neutrino oscillations taking into account the lifetime of the neutrino production process . We find that flavour oscillations in space are washed out when the neutrinos are produced from long lived resonances - and what may be observed in appearance/disappearance experiments is a uniform conversion probability independent of distance. The lifetime of the resonance which produces the neutrinos acts as the the effective baseline of the experiment. For this reason the LSND experiment where neutrinos are produced from muon decay has two orders of magnitude more sensitivity to neutrino mass square difference than other experiments where the neutrinos are produced from pion or kaon decays.We also show that there are no EPR type oscillations of the secondary decay particles.
hep-ph/9410231
Nir Polonsky-3C13-949
Nir Polonsky and Alex Pomarol
Non-Universal GUT Corrections to the Soft Terms and their Implications in Supergravity Models
30 pages, LaTex + RevTex 3, uuencoded postscript file (including 13 figures) is attached. Also available via anonymous ftp from dept.physics.upenn.edu @dir pub\Nir (as a .uu or .ps file). Preprint No. UPR-0627-T
Phys.Rev. D51 (1995) 6532-6549
10.1103/PhysRevD.51.6532
null
hep-ph
null
Potentially large non-universal corrections to the soft supersymmetry breaking parameters arise from their evolution between the Planck and the grand-unification scales. We detail typical patterns of non-universality in GUT models, as well as elaborate on their propagation to the weak scale and on their low-energy implications. Possible corrections to the different scalar quark and lepton masses and the Higgs and the gaugino-Higgsino sector parameters are described in detail, and new allowed regions of the parameter space are pointed out. In particular, the patterns studied often lead to heavier Higgsinos and $t$-scalar. One-loop GUT threshold corrections to the soft parameters are also discussed and shown to be important.
[ { "created": "Thu, 6 Oct 1994 11:37:45 GMT", "version": "v1" } ]
2009-10-28
[ [ "Polonsky", "Nir", "" ], [ "Pomarol", "Alex", "" ] ]
Potentially large non-universal corrections to the soft supersymmetry breaking parameters arise from their evolution between the Planck and the grand-unification scales. We detail typical patterns of non-universality in GUT models, as well as elaborate on their propagation to the weak scale and on their low-energy implications. Possible corrections to the different scalar quark and lepton masses and the Higgs and the gaugino-Higgsino sector parameters are described in detail, and new allowed regions of the parameter space are pointed out. In particular, the patterns studied often lead to heavier Higgsinos and $t$-scalar. One-loop GUT threshold corrections to the soft parameters are also discussed and shown to be important.
2404.13109
Gabriele Rigo
Raffaele Tito D'Agnolo, Paolo Mangini, Gabriele Rigo, Lian-Tao Wang
A Multiverse Outside of the Swampland
15 pages + references, 8 figures
null
null
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Multiverse can arise from landscapes without de Sitter minima. It can be populated during a period of eternal inflation without trans-Planckian field excursions and without flat potentials. This Multiverse can explain the values of the cosmological constant and of the weak scale. In the process of proving these statements we derive a few simple, but counter-intuitive results. We show that it is easy to write models of eternal inflation compatible with the distance and refined de Sitter conjectures. Secondly, tunneling transitions that move fields from a lower-energy vacuum to a higher-energy vacuum and generate baby Universes are possible, and occur during eternal inflation. Finally, we relax the assumption of no de Sitter minima and show that this more standard Multiverse can be populated by Coleman-De Luccia transitions in about 100 $e$-folds of inflation.
[ { "created": "Fri, 19 Apr 2024 18:00:00 GMT", "version": "v1" } ]
2024-04-23
[ [ "D'Agnolo", "Raffaele Tito", "" ], [ "Mangini", "Paolo", "" ], [ "Rigo", "Gabriele", "" ], [ "Wang", "Lian-Tao", "" ] ]
A Multiverse can arise from landscapes without de Sitter minima. It can be populated during a period of eternal inflation without trans-Planckian field excursions and without flat potentials. This Multiverse can explain the values of the cosmological constant and of the weak scale. In the process of proving these statements we derive a few simple, but counter-intuitive results. We show that it is easy to write models of eternal inflation compatible with the distance and refined de Sitter conjectures. Secondly, tunneling transitions that move fields from a lower-energy vacuum to a higher-energy vacuum and generate baby Universes are possible, and occur during eternal inflation. Finally, we relax the assumption of no de Sitter minima and show that this more standard Multiverse can be populated by Coleman-De Luccia transitions in about 100 $e$-folds of inflation.
hep-ph/9904404
Anne Billups
A.H. Mueller (Columbia University)
Parton Saturation at Small x and in Large Nuclei
24 pages, 4 figures
Nucl.Phys.B558:285-303,1999
10.1016/S0550-3213(99)00394-6
CU-TP-937
hep-ph
null
Quark and gluon distributions in the light-cone wavefunction of a high energy hadron or nucleus are calculated in the saturation regime. One loop calculations are performed explicitly using the equivalence between the parton distribution in the light-cone wavefunction and the production distribution of that parton in a current-nucleon (nucleus) scattering. We argue that, except for some overall numerical factors, the Weizsacker- Williams wavefunction correctly gives the physics of the gluon distribution in a light-cone wavefunction.
[ { "created": "Tue, 20 Apr 1999 13:45:55 GMT", "version": "v1" } ]
2011-08-17
[ [ "Mueller", "A. H.", "", "Columbia University" ] ]
Quark and gluon distributions in the light-cone wavefunction of a high energy hadron or nucleus are calculated in the saturation regime. One loop calculations are performed explicitly using the equivalence between the parton distribution in the light-cone wavefunction and the production distribution of that parton in a current-nucleon (nucleus) scattering. We argue that, except for some overall numerical factors, the Weizsacker- Williams wavefunction correctly gives the physics of the gluon distribution in a light-cone wavefunction.
hep-ph/0106081
Gerhard Buchalla
Stefan W. Bosch and Gerhard Buchalla
The Radiative Decays B -> V gamma at Next-to-Leading Order in QCD
discussion on power corrections and references added, otherwise unchanged, version published in NPB
Nucl.Phys.B621:459-478,2002
10.1016/S0550-3213(01)00580-6
CERN-TH/2001-151, MPI-PHT-2001-16
hep-ph
null
We provide a model-independent framework for the analysis of the radiative B-meson decays B -> K* gamma and B -> rho gamma. In particular, we give a systematic discussion of the various contributions to these exclusive processes based on the heavy-quark limit of QCD. We propose a novel factorization formula for the consistent treatment of B -> V gamma matrix elements involving charm (or up-quark) loops, which contribute at leading power in Lambda_QCD/m_B to the decay amplitude. Annihilation topologies are shown to be power suppressed. In some cases they are nevertheless calculable. The approach is similar to the framework of QCD factorization that has recently been formulated for two-body non-leptonic B decays. These results allow us, for the first time, to compute exclusive b -> s(d) gamma decays systematically beyond the leading logarithmic approximation. We present results for these decays complete to next-to-leading order in QCD and to leading order in the heavy-quark limit. Phenomenological implications for various observables of interest are discussed, including direct CP violation, and isospin and U-spin breaking effects.
[ { "created": "Thu, 7 Jun 2001 19:11:58 GMT", "version": "v1" }, { "created": "Fri, 17 May 2002 14:18:58 GMT", "version": "v2" } ]
2010-05-28
[ [ "Bosch", "Stefan W.", "" ], [ "Buchalla", "Gerhard", "" ] ]
We provide a model-independent framework for the analysis of the radiative B-meson decays B -> K* gamma and B -> rho gamma. In particular, we give a systematic discussion of the various contributions to these exclusive processes based on the heavy-quark limit of QCD. We propose a novel factorization formula for the consistent treatment of B -> V gamma matrix elements involving charm (or up-quark) loops, which contribute at leading power in Lambda_QCD/m_B to the decay amplitude. Annihilation topologies are shown to be power suppressed. In some cases they are nevertheless calculable. The approach is similar to the framework of QCD factorization that has recently been formulated for two-body non-leptonic B decays. These results allow us, for the first time, to compute exclusive b -> s(d) gamma decays systematically beyond the leading logarithmic approximation. We present results for these decays complete to next-to-leading order in QCD and to leading order in the heavy-quark limit. Phenomenological implications for various observables of interest are discussed, including direct CP violation, and isospin and U-spin breaking effects.
hep-ph/9511224
Z. Hioki
Zenr\=o Hioki
Structure of Electroweak Radiative Corrections
16 pages, latex, 1 figure (drawn on latex), Lecture at the XIX International School on Theoretical Physics ``Particle Physics and Astrophysics in the Standard Model and Beyond", Bystra, Poland, September 19-26, 1995
Acta Phys.Polon.B27:1569-1579,1996
null
TOKUSHIMA 95-05
hep-ph
null
Looking into the inside of radiative corrections is an interesting subject as a deeper study of the standard electroweak theory after its remarkable success in the precision analyses. I will discuss here a test of ``structure" of the EW radiative corrections to the weak-boson masses, and show that we can now analyze several different parts separately.
[ { "created": "Fri, 3 Nov 1995 10:15:09 GMT", "version": "v1" } ]
2011-01-13
[ [ "Hioki", "Zenrō", "" ] ]
Looking into the inside of radiative corrections is an interesting subject as a deeper study of the standard electroweak theory after its remarkable success in the precision analyses. I will discuss here a test of ``structure" of the EW radiative corrections to the weak-boson masses, and show that we can now analyze several different parts separately.
hep-ph/0102194
Klaus Werner
M. Hladik, H.J. Drescher, S. Ostapchenko, T. Pierog, and K. Werner
Self-Consistency Requirement in High-Energy Nuclear Scattering
7 pages, 6 figures
Phys.Rev.Lett. 86 (2001) 3506-3509
10.1103/PhysRevLett.86.3506
SUBATECH 01-02
hep-ph astro-ph nucl-th
null
Practically all serious calculations of exclusive particle production in ultra-relativistic nuclear or hadronic interactions are performed in the framework of Gribov-Regge theory or the eikonalized parton model scheme. It is the purpose of this paper to point out serious inconsistencies in the above-mentioned approaches. We will demonstrate that requiring theoretical self-consistency reduces the freedom in modeling high energy nuclear scattering enormously. We will introduce a fully self-consistent formulation of the multiple-scattering scheme in the framework of a Gribov-Regge type effective theory. In addition, we develop new computational techniques which allow for the first time a satisfactory solution of the problem in the sense that calculation s of observable quantities can be done strictly within a self-consistent formalism.
[ { "created": "Thu, 15 Feb 2001 17:01:12 GMT", "version": "v1" } ]
2016-09-06
[ [ "Hladik", "M.", "" ], [ "Drescher", "H. J.", "" ], [ "Ostapchenko", "S.", "" ], [ "Pierog", "T.", "" ], [ "Werner", "K.", "" ] ]
Practically all serious calculations of exclusive particle production in ultra-relativistic nuclear or hadronic interactions are performed in the framework of Gribov-Regge theory or the eikonalized parton model scheme. It is the purpose of this paper to point out serious inconsistencies in the above-mentioned approaches. We will demonstrate that requiring theoretical self-consistency reduces the freedom in modeling high energy nuclear scattering enormously. We will introduce a fully self-consistent formulation of the multiple-scattering scheme in the framework of a Gribov-Regge type effective theory. In addition, we develop new computational techniques which allow for the first time a satisfactory solution of the problem in the sense that calculation s of observable quantities can be done strictly within a self-consistent formalism.
hep-ph/9903246
Yuri V. Kovchegov
Yuri V. Kovchegov, Larry McLerran (University of Minnesota)
Diffractive Structure Function in a Quasi-Classical Approximation
11 pages, 4 figures, REVTeX, some changes included, a mistake is corrected
Phys.Rev.D60:054025,1999; Erratum-ibid.D62:019901,2000
10.1103/PhysRevD.60.054025 10.1103/PhysRevD.62.019901
NUC-MN-99/2-T, TPI-MINN-99/10, UMN-TH-99/1746
hep-ph
null
We derive an expression for diffractive F_2 structure function which should be valid at small x for quasi-elastic scattering on a hadron and for quasi-elastic scattering on a large nucleus. This expression includes multiple rescatterings of the quark-antiquark pair produced by the virtual photon off the sources of color charge in a quasi-classical approximation. We find that there is a relation between such diffractive production and inclusive processes. In the former, one averages over all colors of sources before squaring the amplitude, and in the latter one first squares the amplitude and then averages it in the hadron's or nuclear wave function. We show that in the limit of a large virtuality of the photon Q^2 the diffractive structure function becomes linearly proportional to the gluon distribution of the hadron or nucleus, therefore proving that in this sense diffraction is a leading twist effect.
[ { "created": "Wed, 3 Mar 1999 15:21:44 GMT", "version": "v1" }, { "created": "Wed, 21 Apr 1999 21:53:49 GMT", "version": "v2" }, { "created": "Mon, 6 Mar 2000 19:03:37 GMT", "version": "v3" } ]
2014-11-17
[ [ "Kovchegov", "Yuri V.", "", "University of Minnesota" ], [ "McLerran", "Larry", "", "University of Minnesota" ] ]
We derive an expression for diffractive F_2 structure function which should be valid at small x for quasi-elastic scattering on a hadron and for quasi-elastic scattering on a large nucleus. This expression includes multiple rescatterings of the quark-antiquark pair produced by the virtual photon off the sources of color charge in a quasi-classical approximation. We find that there is a relation between such diffractive production and inclusive processes. In the former, one averages over all colors of sources before squaring the amplitude, and in the latter one first squares the amplitude and then averages it in the hadron's or nuclear wave function. We show that in the limit of a large virtuality of the photon Q^2 the diffractive structure function becomes linearly proportional to the gluon distribution of the hadron or nucleus, therefore proving that in this sense diffraction is a leading twist effect.
0902.2379
Adriano Gomes doff
A.Doff and A.A.Natale
Mass and width of a composite Higgs boson
New reference and new figure added. Additional discussion about experimental constraints. Typos corrected
Phys.Lett.B677:301-305,2009
10.1016/j.physletb.2009.05.045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scalar Higgs boson mass in a Technicolor model was obtained by Elias and Scadron with the analysis of an homogeneous Bethe-Salpeter equation (BSE), however it was performed before the most recent developments of walking gauge theories. It was not observed in their work that dynamically generated technifermion mass may vary according to the theory dynamics that forms the scalar bound state. This will be done in this work and we also call attention that their calculation must change to take into account the normalization condition of the BSE. We compute the width of the composite boson and show how the gauge group and fermion content of a technicolor theory can be inferred from the measurement of the mass and width of the scalar boson.
[ { "created": "Fri, 13 Feb 2009 20:01:47 GMT", "version": "v1" }, { "created": "Mon, 18 May 2009 19:41:17 GMT", "version": "v2" } ]
2010-04-21
[ [ "Doff", "A.", "" ], [ "Natale", "A. A.", "" ] ]
The scalar Higgs boson mass in a Technicolor model was obtained by Elias and Scadron with the analysis of an homogeneous Bethe-Salpeter equation (BSE), however it was performed before the most recent developments of walking gauge theories. It was not observed in their work that dynamically generated technifermion mass may vary according to the theory dynamics that forms the scalar bound state. This will be done in this work and we also call attention that their calculation must change to take into account the normalization condition of the BSE. We compute the width of the composite boson and show how the gauge group and fermion content of a technicolor theory can be inferred from the measurement of the mass and width of the scalar boson.
hep-ph/9509209
C.-P. Yuan
C.-P. Yuan (Michigan State Univ.)
Top Quark Physics at the Tevatron
7 pages, uuencoded PS file. Talk given at the International Workshop on Elementary Particle Physics: Present and Future, Univ. of Valencia, Valencia, Spain, June 5 to 9, 1995; and at the Fermilab Users Annual Meeting, Fermilab, Illinois, July 13 \& 14, 1995
null
null
MSUHEP-50831
hep-ph
null
We discuss physics of the top quark at the Fermilab Tevatron. By the year 2000, many properties of the top quark can be measured at the Tevatron.
[ { "created": "Fri, 1 Sep 1995 15:29:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yuan", "C. -P.", "", "Michigan State Univ." ] ]
We discuss physics of the top quark at the Fermilab Tevatron. By the year 2000, many properties of the top quark can be measured at the Tevatron.
hep-ph/0103250
Masayasu Harada
Masayasu Harada (Nagoya Univ.)
New Pattern of Chiral Symmetry Restoration
2 pages: Talk given at YITP workshop ``Fundamental Problems and Applications of Quantum Field Theory'' (December 20-22, 2000, Yukawa Institute, Kyoto, Japan)
null
null
DPNU-01-03
hep-ph
null
In this talk I summarize our recent works on the chiral symmetry restoration in the large flavor QCD using the hidden local symmetry (HLS) as an effective field theory of QCD. Bare parameters in the HLS are determined by matching the HLS with QCD at the matching scale through the Wilsoninan matching conditions. This Wilsonian matching leads to the vector manifestation of the Wigner realization of the chiral symmetry in which the symmetry is restored by the massless degenerate pion (and its flavor partners) and rho meson (and its flavor partners) as the chiral partner.
[ { "created": "Fri, 23 Mar 2001 11:52:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Harada", "Masayasu", "", "Nagoya Univ." ] ]
In this talk I summarize our recent works on the chiral symmetry restoration in the large flavor QCD using the hidden local symmetry (HLS) as an effective field theory of QCD. Bare parameters in the HLS are determined by matching the HLS with QCD at the matching scale through the Wilsoninan matching conditions. This Wilsonian matching leads to the vector manifestation of the Wigner realization of the chiral symmetry in which the symmetry is restored by the massless degenerate pion (and its flavor partners) and rho meson (and its flavor partners) as the chiral partner.
hep-ph/0203120
Stefan Dittmaier
Stefan Dittmaier and Andreas Kaiser
Photonic and QCD radiative corrections to Higgs-boson production in mu+ mu- --> f fbar
39 pages, latex, 19 postscript files
Phys.Rev. D65 (2002) 113003
10.1103/PhysRevD.65.113003
DESY 02-024, PSI-PR-02-02
hep-ph
null
The photonic and QCD radiative corrections at next-to-leading order are calculated for fermion-pair production at muon colliders, maintaining the full mass dependence and helicity information of the muons and the produced fermions. Higher-order effects of initial-state radiation are included at the leading logarithmic level. In the calculation particular attention is paid to the issue of gauge invariance in the vicinity of resonances. The most important corrections are presented in analytical form. The detailed numerical discussion concentrates on the corrections to the (s-channel) Higgs-boson resonances in the Standard Model and its minimal supersymmetric extension. The results show that photonic initial- and QCD final-state corrections are very important in a precision study of Higgs resonances, but that (photonic) initial-final interferences are widely suppressed and only modify the non-resonant background.
[ { "created": "Wed, 13 Mar 2002 16:03:42 GMT", "version": "v1" } ]
2009-11-07
[ [ "Dittmaier", "Stefan", "" ], [ "Kaiser", "Andreas", "" ] ]
The photonic and QCD radiative corrections at next-to-leading order are calculated for fermion-pair production at muon colliders, maintaining the full mass dependence and helicity information of the muons and the produced fermions. Higher-order effects of initial-state radiation are included at the leading logarithmic level. In the calculation particular attention is paid to the issue of gauge invariance in the vicinity of resonances. The most important corrections are presented in analytical form. The detailed numerical discussion concentrates on the corrections to the (s-channel) Higgs-boson resonances in the Standard Model and its minimal supersymmetric extension. The results show that photonic initial- and QCD final-state corrections are very important in a precision study of Higgs resonances, but that (photonic) initial-final interferences are widely suppressed and only modify the non-resonant background.
hep-ph/0609268
Jean-Philippe Lansberg
J.P. Lansberg, T.N. Pham
Two-photon width of eta_b, eta'_b and eta''_b from Heavy-Quark Spin Symmetry
3 pages, Revtex4; v2: 2 references added
Phys.Rev.D75:017501,2007
10.1103/PhysRevD.75.017501
null
hep-ph hep-ex
null
We predict the two-photon width of the pseudoscalar bottomonia, Gamma(eta_b -> gamma gamma), Gamma(eta'_b -> gamma gamma) and Gamma(eta''_b -> gamma gamma) within a Heavy-Quark Spin-Symmetry setting following the same line as our recent work for the corresponding decays for charmonia. Binding-energy effects are included for excited states and are shown to shift up the eta'_b and eta''_b widths by 10 %. We point out that the essentially model independent ratio Gamma(eta_b -> gamma gamma)/Gamma(Upsilon -> ll) and the branching ratio BR(eta_b -> gamma gamma) obtained could be used to extract the coupling constant alpha_s.
[ { "created": "Tue, 26 Sep 2006 13:10:40 GMT", "version": "v1" }, { "created": "Tue, 3 Oct 2006 15:40:39 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lansberg", "J. P.", "" ], [ "Pham", "T. N.", "" ] ]
We predict the two-photon width of the pseudoscalar bottomonia, Gamma(eta_b -> gamma gamma), Gamma(eta'_b -> gamma gamma) and Gamma(eta''_b -> gamma gamma) within a Heavy-Quark Spin-Symmetry setting following the same line as our recent work for the corresponding decays for charmonia. Binding-energy effects are included for excited states and are shown to shift up the eta'_b and eta''_b widths by 10 %. We point out that the essentially model independent ratio Gamma(eta_b -> gamma gamma)/Gamma(Upsilon -> ll) and the branching ratio BR(eta_b -> gamma gamma) obtained could be used to extract the coupling constant alpha_s.
1209.2427
Bibhushan Shakya
Bibhushan Shakya
A 130 GeV Gamma Ray Signal from Supersymmetry
16 pages, 2 figures. Fit to Fermi data updated to include data for the full spectrum where possible. Main results and conclusions unchanged
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The viability of neutralino dark matter as an explanation of the 130 GeV gamma ray signal from the Galactic Center recently observed by the Fermi Large Area Telescope is examined. It is found that the signal can be compatible with a sharp feature from internal bremsstrahlung from a mostly bino dark matter particle of mass around 145 GeV, augmented by a contribution from annihilation into gamma+Z via a small wino admixture. This scenario circumvents the problematic overproduction of lower energy continuum photons that plague line interpretations of this signal. Sleptons approximately degenerate in mass with the neutralino are required to enhance the internal bremsstrahlung feature.
[ { "created": "Tue, 11 Sep 2012 20:06:17 GMT", "version": "v1" }, { "created": "Tue, 16 Oct 2012 04:40:22 GMT", "version": "v2" } ]
2012-10-17
[ [ "Shakya", "Bibhushan", "" ] ]
The viability of neutralino dark matter as an explanation of the 130 GeV gamma ray signal from the Galactic Center recently observed by the Fermi Large Area Telescope is examined. It is found that the signal can be compatible with a sharp feature from internal bremsstrahlung from a mostly bino dark matter particle of mass around 145 GeV, augmented by a contribution from annihilation into gamma+Z via a small wino admixture. This scenario circumvents the problematic overproduction of lower energy continuum photons that plague line interpretations of this signal. Sleptons approximately degenerate in mass with the neutralino are required to enhance the internal bremsstrahlung feature.
1401.5078
Zhong-Bo Kang
Miguel G. Echevarria, Ahmad Idilbi, Zhong-Bo Kang and Ivan Vitev
QCD Evolution of the Sivers Asymmetry
17 pages, 13 figures, published version in PRD
Phys. Rev. D 89, 074013 (2014)
10.1103/PhysRevD.89.074013
NIKHEF 2014-004
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the QCD evolution of the Sivers effect in both semi-inclusive deep inelastic scattering (SIDIS) and Drell-Yan production (DY). We pay close attention to the non-perturbative spin-independent Sudakov factor in the evolution formalism and find a universal form which can describe reasonably well the experimental data on the transverse momentum distributions in SIDIS, DY lepton pair and $W/Z$ production. With this Sudakov factor at hand, we perform a global fitting of all the experimental data on the Sivers asymmetry in SIDIS from HERMES, COMPASS and Jefferson Lab. We then make predictions for the Sivers asymmetry in DY lepton pair and $W$ production that can be compared to the future experimental measurements to test the sign change of the Sivers functions between SIDIS and DY processes and constrain the sea quark Sivers functions.
[ { "created": "Mon, 20 Jan 2014 21:00:22 GMT", "version": "v1" }, { "created": "Fri, 4 Apr 2014 23:06:44 GMT", "version": "v2" } ]
2014-04-23
[ [ "Echevarria", "Miguel G.", "" ], [ "Idilbi", "Ahmad", "" ], [ "Kang", "Zhong-Bo", "" ], [ "Vitev", "Ivan", "" ] ]
We study the QCD evolution of the Sivers effect in both semi-inclusive deep inelastic scattering (SIDIS) and Drell-Yan production (DY). We pay close attention to the non-perturbative spin-independent Sudakov factor in the evolution formalism and find a universal form which can describe reasonably well the experimental data on the transverse momentum distributions in SIDIS, DY lepton pair and $W/Z$ production. With this Sudakov factor at hand, we perform a global fitting of all the experimental data on the Sivers asymmetry in SIDIS from HERMES, COMPASS and Jefferson Lab. We then make predictions for the Sivers asymmetry in DY lepton pair and $W$ production that can be compared to the future experimental measurements to test the sign change of the Sivers functions between SIDIS and DY processes and constrain the sea quark Sivers functions.
hep-ph/0303170
Philip R. Page
Philip R. Page
Selection rules for J^PC Exotic Hybrid Meson Decay in Large-N_c
16 pages, LaTeX. Main paper shortened/rewritten and appendices expanded. Implications for phenomenology of exotic hybrid mesons clarified
Phys.Rev. D70 (2004) 016004
10.1103/PhysRevD.70.016004
LA-UR-03-1658
hep-ph
null
The coupling of a neutral hybrid {1,3,5...}^-+ exotic particle (or current) to two neutral (hybrid) meson particles with the same J^PC and J=0 is proved to be sub-leading to the usual large-N_c QCD counting. The coupling of the same exotic particle to certain two - (hybrid) meson currents with the same J^PC and J=0 is also sub-leading. The decay of a {1,3,5...}^-+ hybrid to eta pi^0, eta' pi^0, eta' eta, eta(1295) pi^0, pi(1300)^0 pi0, eta(1440) pi^0, a_0(980)^0 sigma or f_0(980) sigma is sub-leading, assuming that these final state particles are (hybrid) mesons in the limit of large N_c.
[ { "created": "Wed, 19 Mar 2003 21:43:52 GMT", "version": "v1" }, { "created": "Mon, 17 May 2004 19:25:17 GMT", "version": "v2" } ]
2009-11-10
[ [ "Page", "Philip R.", "" ] ]
The coupling of a neutral hybrid {1,3,5...}^-+ exotic particle (or current) to two neutral (hybrid) meson particles with the same J^PC and J=0 is proved to be sub-leading to the usual large-N_c QCD counting. The coupling of the same exotic particle to certain two - (hybrid) meson currents with the same J^PC and J=0 is also sub-leading. The decay of a {1,3,5...}^-+ hybrid to eta pi^0, eta' pi^0, eta' eta, eta(1295) pi^0, pi(1300)^0 pi0, eta(1440) pi^0, a_0(980)^0 sigma or f_0(980) sigma is sub-leading, assuming that these final state particles are (hybrid) mesons in the limit of large N_c.
1204.4120
Yi Sun
Yi Sun and Hao-Ran Chang
One loop integrals reduction
14 pages, 1 figure
CHINESE PHYSICS C 36 (2012) 1055
10.1088/1674-1137/36/11/004
USTC-ICTS-12-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By further examining the symmetry of external momenta and masses in Feynman integrals, we fulfilled the method proposed by Battistel and Dallabona, and showed that recursion relations in this method can be applied to simplify Feynman integrals directly.
[ { "created": "Wed, 18 Apr 2012 16:13:22 GMT", "version": "v1" } ]
2013-03-12
[ [ "Sun", "Yi", "" ], [ "Chang", "Hao-Ran", "" ] ]
By further examining the symmetry of external momenta and masses in Feynman integrals, we fulfilled the method proposed by Battistel and Dallabona, and showed that recursion relations in this method can be applied to simplify Feynman integrals directly.
1310.2248
Nausheen Shah
Marcela Carena, Ian Low, Nausheen R. Shah, and Carlos E. M. Wagner
Impersonating the Standard Model Higgs Boson: Alignment without Decoupling
42 Pages, 8 figures
null
10.1007/JHEP04(2014)015
ANL-HEP-PR-13-50, EFI-13-27, FERMILAB-PUB-13-455-T, MCTP-13-31
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the $Z$ boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to "alignment without decoupling", therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of $\tan\beta$ for which this happens are derived in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. Moreover, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the $m_A - \tan\beta$ parameter space.
[ { "created": "Tue, 8 Oct 2013 20:00:04 GMT", "version": "v1" } ]
2015-06-17
[ [ "Carena", "Marcela", "" ], [ "Low", "Ian", "" ], [ "Shah", "Nausheen R.", "" ], [ "Wagner", "Carlos E. M.", "" ] ]
In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the $Z$ boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to "alignment without decoupling", therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of $\tan\beta$ for which this happens are derived in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. Moreover, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the $m_A - \tan\beta$ parameter space.
1205.4151
Jong-Chul Park
Bumseok Kyae and Jong-Chul Park
130 GeV Fermi gamma-ray line from dark matter decay
10 pages, 1 figure; typos fixed, version published in PLB
Phys. Lett. B 718 (2013) 1425
10.1016/j.physletb.2012.12.041
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The 130 GeV gamma-ray line based on tentative analyses on the Fermi-LAT data is hard to be understood with dark matter annihilation in the conventional framework of the MSSM. We point out that it can be nicely explained with two body decay of a scalar dark matter ($\tilde{\phi}_{\rm DM}\rightarrow\gamma\gamma$) by the dimension 6 operator suppressed with the mass of the grand unification scale ($\sim 10^{16}$ GeV), ${\cal L}\supset|\tilde{\phi}_{\rm DM}|^2F_{\mu\nu}F^{\mu\nu}/M_{\rm GUT}^2$, in which the scalar dark matter $\tilde{\phi}_{\rm DM}$ develops a TeV scale vacuum expectation value. We propose a viable model explaining the 130 GeV gamma-ray line.
[ { "created": "Fri, 18 May 2012 12:40:57 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2012 02:11:31 GMT", "version": "v2" }, { "created": "Mon, 28 Jan 2013 10:58:34 GMT", "version": "v3" } ]
2015-06-05
[ [ "Kyae", "Bumseok", "" ], [ "Park", "Jong-Chul", "" ] ]
The 130 GeV gamma-ray line based on tentative analyses on the Fermi-LAT data is hard to be understood with dark matter annihilation in the conventional framework of the MSSM. We point out that it can be nicely explained with two body decay of a scalar dark matter ($\tilde{\phi}_{\rm DM}\rightarrow\gamma\gamma$) by the dimension 6 operator suppressed with the mass of the grand unification scale ($\sim 10^{16}$ GeV), ${\cal L}\supset|\tilde{\phi}_{\rm DM}|^2F_{\mu\nu}F^{\mu\nu}/M_{\rm GUT}^2$, in which the scalar dark matter $\tilde{\phi}_{\rm DM}$ develops a TeV scale vacuum expectation value. We propose a viable model explaining the 130 GeV gamma-ray line.
1212.2873
Swagato Banerjee
Swagato Banerjee, Jan Kalinowski, Wojciech Kotlarski, Tomasz Przedzinski and Zbigniew Was
Ascertaining the spin for new resonances decaying into tau+ tau- at Hadron Colliders
17 pages, 16 encapsulated postscript figures
null
10.1140/epjc/s10052-013-2313-1
IFJPAN-IV-2012-13; CERN-PH-TH-2012-347
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Evidence of a new particle with mass ~125 GeV decaying into a pair of tau leptons at the Large Hadron Collider spurs interest in ascertaining its spin in this channel. Here we present a comparative study between spin-0 and spin-2 nature of this new particle, using spin correlations and decay product directions. The TauSpinner algorithm is used to re-weight distributions from qqbar -> gamma/Z -> tau+ tau- sample to simulate a spin-2 state exchange. The method is based on supplementing the Standard Model matrix elements with those arising from presence of a new interaction. Studies with simulated samples demonstrate the discrimination power between these spin hypotheses based on data collected at the Large Hadron Collider.
[ { "created": "Wed, 12 Dec 2012 16:36:59 GMT", "version": "v1" } ]
2015-06-12
[ [ "Banerjee", "Swagato", "" ], [ "Kalinowski", "Jan", "" ], [ "Kotlarski", "Wojciech", "" ], [ "Przedzinski", "Tomasz", "" ], [ "Was", "Zbigniew", "" ] ]
Evidence of a new particle with mass ~125 GeV decaying into a pair of tau leptons at the Large Hadron Collider spurs interest in ascertaining its spin in this channel. Here we present a comparative study between spin-0 and spin-2 nature of this new particle, using spin correlations and decay product directions. The TauSpinner algorithm is used to re-weight distributions from qqbar -> gamma/Z -> tau+ tau- sample to simulate a spin-2 state exchange. The method is based on supplementing the Standard Model matrix elements with those arising from presence of a new interaction. Studies with simulated samples demonstrate the discrimination power between these spin hypotheses based on data collected at the Large Hadron Collider.
hep-ph/9704207
null
A.V. Radyushkin
Nonforward Parton Distributions
Final version, to be published in Phys.Rev.D
Phys.Rev.D56:5524-5557,1997
10.1103/PhysRevD.56.5524
JLAB-THY-97-10
hep-ph
null
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements <p'|O|p> of quark and gluon light-cone operators. We describe two types of nonperturbative functions parametrizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F_\zeta (X;t), discuss their spectral properties, evolution equations which they satisfy, basic uses and general aspects of factorization for hard exclusive processes.
[ { "created": "Wed, 2 Apr 1997 00:43:42 GMT", "version": "v1" }, { "created": "Wed, 2 Apr 1997 05:59:07 GMT", "version": "v2" }, { "created": "Tue, 8 Apr 1997 23:00:24 GMT", "version": "v3" }, { "created": "Sat, 12 Apr 1997 01:33:47 GMT", "version": "v4" }, { "created": "Mon, 19 May 1997 15:48:06 GMT", "version": "v5" }, { "created": "Thu, 5 Jun 1997 17:38:09 GMT", "version": "v6" }, { "created": "Fri, 25 Jul 1997 22:41:58 GMT", "version": "v7" } ]
2014-11-17
[ [ "Radyushkin", "A. V.", "" ] ]
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements <p'|O|p> of quark and gluon light-cone operators. We describe two types of nonperturbative functions parametrizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F_\zeta (X;t), discuss their spectral properties, evolution equations which they satisfy, basic uses and general aspects of factorization for hard exclusive processes.
2212.09725
Marco Ruggieri
Pooja, Santosh K. Das, Vincenzo Greco and Marco Ruggieri
Anisotropic fluctuations of angular momentum of heavy quarks in the Glasma
10 pages, 6 figures
null
null
null
hep-ph hep-lat nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
We study the evolution of the angular momentum of the heavy quarks in the very early stage of high energy nuclear collisions, in which the background is made of evolving Glasma fields. Given the novelty of the problem, we limit ourselves to the use of toy heavy quarks with a large, unphysical mass, in order to implement the kinetic equations for the angular momentum in the non-relativistic limit. We find that as a consequence of the anisotropy of the background fields, angular momentum fluctuations are also anisotropic: we understand this in simple terms relating the fluctuations of the angular momentum, $L$, to those of linear momentum. While orbital angular momentum diffuses and develops substantial fluctuations and anisotropies, the spin does not. Hence, we can identify the fluctuations of $L$ with those of the total angular momentum $J=L + S$. Therefore, our study suggests that the total angular momentum of the heavy quarks in the early stage of high energy nuclear collisions will present anisotropic fluctuations.
[ { "created": "Mon, 19 Dec 2022 18:50:58 GMT", "version": "v1" } ]
2022-12-20
[ [ "Pooja", "", "" ], [ "Das", "Santosh K.", "" ], [ "Greco", "Vincenzo", "" ], [ "Ruggieri", "Marco", "" ] ]
We study the evolution of the angular momentum of the heavy quarks in the very early stage of high energy nuclear collisions, in which the background is made of evolving Glasma fields. Given the novelty of the problem, we limit ourselves to the use of toy heavy quarks with a large, unphysical mass, in order to implement the kinetic equations for the angular momentum in the non-relativistic limit. We find that as a consequence of the anisotropy of the background fields, angular momentum fluctuations are also anisotropic: we understand this in simple terms relating the fluctuations of the angular momentum, $L$, to those of linear momentum. While orbital angular momentum diffuses and develops substantial fluctuations and anisotropies, the spin does not. Hence, we can identify the fluctuations of $L$ with those of the total angular momentum $J=L + S$. Therefore, our study suggests that the total angular momentum of the heavy quarks in the early stage of high energy nuclear collisions will present anisotropic fluctuations.
hep-ph/0208023
Claudio Coriano
A. Cafarella, C. Coriano', M. Guzzi and D. Martello
Superstring Relics, Supersymmetric Fragmentation and UHECR
7 pages 4 Figs. Plenary Talk presented by Claudio Coriano' at the 1st Intl. Conf. on String Phenomenology, Oxford, UK, July 6-11, 2002
null
10.1142/9789812704917_0007
null
hep-ph
null
Superstring theory predicts the existence of relic metastable particles whose average lifetime is longer than the age of the universe and which could, in principle, be good dark matter candidates. At the same time, these states would be responsible for the Ultra High Energy Cosmic Rays (UHECR) events which will be searched for by various experimental collaborations in the near future. We describe a possible phenomenological path which could be followed in order to search for new physics in their detection.
[ { "created": "Fri, 2 Aug 2002 15:08:40 GMT", "version": "v1" }, { "created": "Sun, 4 Aug 2002 19:19:19 GMT", "version": "v2" } ]
2017-08-23
[ [ "Cafarella", "A.", "" ], [ "Coriano'", "C.", "" ], [ "Guzzi", "M.", "" ], [ "Martello", "D.", "" ] ]
Superstring theory predicts the existence of relic metastable particles whose average lifetime is longer than the age of the universe and which could, in principle, be good dark matter candidates. At the same time, these states would be responsible for the Ultra High Energy Cosmic Rays (UHECR) events which will be searched for by various experimental collaborations in the near future. We describe a possible phenomenological path which could be followed in order to search for new physics in their detection.
1304.6835
Jennifer Girrbach
Andrzej J. Buras and Jennifer Girrbach
Stringent Tests of Constrained Minimal Flavour Violation through Delta F=2 Transitions
26 pages, 8 figures
The European Physical Journal C, volume 73, number 9, pages 1-14, year 2013
10.1140/epjc/s10052-013-2560-1
FLAVOUR(267104)-ERC-40
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New Physics contributions to Delta F=2 transitions in models with constrained Minimal Flavour Violation (CMFV), are parametrized by a single variable S(v), the value of the real box diagram function. With already precise experimental values of epsilon_K, Delta M_d, Delta M_s, CP-asymmetry S_{psi K_S} and of hat{B}_K entering the evaluation of epsilon_K, the future of CMFV in the Delta F=2 sector depends crucially on the values of |Vcb|, |Vub|, gamma, F_{B_s} sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}}. The ratio xi of the latter two parameters, rather precisely determined from lattice calculations, allows then together with Delta M_s/Delta M_d and S_{psi K_S} to determine the range of gamma in the unitarity triangle independently of the value of S(v). Imposing in addition the constraints from epsilon_K and Delta M_d allows to determine the favorite CMFV values of |Vcb|, |Vub|, F_{B_s} sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}} as functions of S(v) and gamma. The |Vcb|^4 dependence of epsilon_K allows to determine |Vcb| for a given S(v) and gamma with a higher precision than it is presently possible using tree-level decays. The same applies to |Vub|, |Vtd| and |Vts| that are automatically determined as functions of S(v) and gamma. Typically F_{B_s}sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}} have to be significantly lower than their present lattice values, while |Vcb| has to be significantly higher than its tree-level determination. The region in the space of these three parameters allowed by CMFV indicates visible problems in this class of models and hints for the presence of new sources of flavour violation and/or new local operators in Delta F=2 data that are strongly suppressed in these models. As a byproduct we propose to reduce the present uncertainty in the charm contribution toepsilon_K by using the experimental value of Delta M_K.
[ { "created": "Thu, 25 Apr 2013 08:58:15 GMT", "version": "v1" } ]
2013-11-11
[ [ "Buras", "Andrzej J.", "" ], [ "Girrbach", "Jennifer", "" ] ]
New Physics contributions to Delta F=2 transitions in models with constrained Minimal Flavour Violation (CMFV), are parametrized by a single variable S(v), the value of the real box diagram function. With already precise experimental values of epsilon_K, Delta M_d, Delta M_s, CP-asymmetry S_{psi K_S} and of hat{B}_K entering the evaluation of epsilon_K, the future of CMFV in the Delta F=2 sector depends crucially on the values of |Vcb|, |Vub|, gamma, F_{B_s} sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}}. The ratio xi of the latter two parameters, rather precisely determined from lattice calculations, allows then together with Delta M_s/Delta M_d and S_{psi K_S} to determine the range of gamma in the unitarity triangle independently of the value of S(v). Imposing in addition the constraints from epsilon_K and Delta M_d allows to determine the favorite CMFV values of |Vcb|, |Vub|, F_{B_s} sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}} as functions of S(v) and gamma. The |Vcb|^4 dependence of epsilon_K allows to determine |Vcb| for a given S(v) and gamma with a higher precision than it is presently possible using tree-level decays. The same applies to |Vub|, |Vtd| and |Vts| that are automatically determined as functions of S(v) and gamma. Typically F_{B_s}sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}} have to be significantly lower than their present lattice values, while |Vcb| has to be significantly higher than its tree-level determination. The region in the space of these three parameters allowed by CMFV indicates visible problems in this class of models and hints for the presence of new sources of flavour violation and/or new local operators in Delta F=2 data that are strongly suppressed in these models. As a byproduct we propose to reduce the present uncertainty in the charm contribution toepsilon_K by using the experimental value of Delta M_K.
1410.4220
Hartmut Abele
Bastian Maerkisch, Hartmut Abele
Measurement of the Axial-Vector Coupling Constant $g_A$ in Neutron Beta Decay
Proceedings of the 8th International Workshop on the CKM Unitarity Triangle (CKM 2014), Vienna, Austria, September 8-12, 2014
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The matrix element \Vud of the CKM matrix can be determined by two independent measurements in neutron decay: the neutron lifetime $\tau_n$ and the ratio of coupling constants $\lambda=g_A/g_V$, which is most precisely determined by measurements of the beta asymmetry angular correlation coefficient~$A$. We present recent progress on the determination of these coupling constants.
[ { "created": "Wed, 15 Oct 2014 20:29:35 GMT", "version": "v1" } ]
2014-10-17
[ [ "Maerkisch", "Bastian", "" ], [ "Abele", "Hartmut", "" ] ]
The matrix element \Vud of the CKM matrix can be determined by two independent measurements in neutron decay: the neutron lifetime $\tau_n$ and the ratio of coupling constants $\lambda=g_A/g_V$, which is most precisely determined by measurements of the beta asymmetry angular correlation coefficient~$A$. We present recent progress on the determination of these coupling constants.
2009.01380
Daniel Elbio Lopez
Daniel E. Lopez-Fogliani and Carlos Munoz
Searching for Supersymmetry: The $\mu\nu$SSM
A short review of the $\mu \nu$SSM prepared by invitation for EPJ Special Topics on "Supersymmetry and Unification" -edited by U. Chattopadhyay and S. Roy- 42 pages, 7 figures
null
10.1140/epjst/e2020-000114-9
null
hep-ph astro-ph.HE hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the role played by the '$\mu$ from $\nu$' supersymmetric standard model ($\mu \nu$SSM) in the search for supersymmetry. First, we discuss its theoretical motivation, that is the simultaneous solution of $\mu$- and $\nu$-problems through the introduction of right-handed neutrinos. The latter produces $R$-parity violation (RPV), giving rise to interesting signals of new physics. As by-products, in the $\mu\nu$SSM there are dark matter candidates, and electroweak baryogenesis can be realized. Then, we survey signals by which the model could be tested at the large hadron collider (LHC). In addition to the enlarged Higgs sector with sneutrinos, we put special emphasis in analyzing the intimate connection between the lightest supersymmetric particle (LSP) lifetime and the size of neutrino Yukawa couplings. Displaced vertices and/or multileptons are some of the interesting signatures that can be probed. Finally, we discuss possible extensions of the $\mu\nu$SSM such as the inclusion in the superpotential of the conventional trilinear lepton-number violating couplings, the addition of an extra $U(1)'$ gauge group to the symmetry of the standard model, or the reinterpretation of the Higgs doublets as a fourth family of leptons superfields motivating the existence of a fourth family of vector-like quark doublet superfields.
[ { "created": "Wed, 2 Sep 2020 22:59:13 GMT", "version": "v1" } ]
2020-12-30
[ [ "Lopez-Fogliani", "Daniel E.", "" ], [ "Munoz", "Carlos", "" ] ]
We review the role played by the '$\mu$ from $\nu$' supersymmetric standard model ($\mu \nu$SSM) in the search for supersymmetry. First, we discuss its theoretical motivation, that is the simultaneous solution of $\mu$- and $\nu$-problems through the introduction of right-handed neutrinos. The latter produces $R$-parity violation (RPV), giving rise to interesting signals of new physics. As by-products, in the $\mu\nu$SSM there are dark matter candidates, and electroweak baryogenesis can be realized. Then, we survey signals by which the model could be tested at the large hadron collider (LHC). In addition to the enlarged Higgs sector with sneutrinos, we put special emphasis in analyzing the intimate connection between the lightest supersymmetric particle (LSP) lifetime and the size of neutrino Yukawa couplings. Displaced vertices and/or multileptons are some of the interesting signatures that can be probed. Finally, we discuss possible extensions of the $\mu\nu$SSM such as the inclusion in the superpotential of the conventional trilinear lepton-number violating couplings, the addition of an extra $U(1)'$ gauge group to the symmetry of the standard model, or the reinterpretation of the Higgs doublets as a fourth family of leptons superfields motivating the existence of a fourth family of vector-like quark doublet superfields.
0901.3371
Chien-Yi Chen
Chien-Yi Chen and Otto C. W. Kong
Leptonic Radiative Decay in Supersymmetry without R parity
Comments: 24 pages, 12 figures, 3 table, RevTex; Corrected typos, 2 added references for section 1. The proof-read version to be published in Phys. Rev. D
Phys.Rev.D79:115013,2009
10.1103/PhysRevD.79.115013
NCU-HEP-k029
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a detailed analysis together with exact numerical calculations on one-loop contributions to the branching ratio of the radiative decay of $\mu$ and $\tau$, namely $\mu \to e \gamma$, $\tau \to e \gamma$, and $\tau \to\mu \gamma$ from supersymmetry without R parity, focusing on contributions involving bilinear couplings. A numerical study is performed to obtain explicit bounds on the parameters under the present experimental limit. We present, and use in the calculation, formulas for exact mass eigenstate effective couplings. In this sense, we present an exact analysis free from approximation for the first time. After comparing our results against the closest early analysis, we discovered a major difference in resulted constraints on some ${\mu_i^*} {B_j}$ combinations. Constraints from neutrino masses on the parameters were considered. Our result indicates that the branching ratio measurement on $\mu \to e \gamma$ down to $10^{-13}-10^{-14}$ and beyond, as targeted by the MEG experiment, has a chance of observing decay from the R-parity violating scenario.
[ { "created": "Wed, 21 Jan 2009 22:12:15 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2009 13:19:02 GMT", "version": "v2" } ]
2009-08-03
[ [ "Chen", "Chien-Yi", "" ], [ "Kong", "Otto C. W.", "" ] ]
We present a detailed analysis together with exact numerical calculations on one-loop contributions to the branching ratio of the radiative decay of $\mu$ and $\tau$, namely $\mu \to e \gamma$, $\tau \to e \gamma$, and $\tau \to\mu \gamma$ from supersymmetry without R parity, focusing on contributions involving bilinear couplings. A numerical study is performed to obtain explicit bounds on the parameters under the present experimental limit. We present, and use in the calculation, formulas for exact mass eigenstate effective couplings. In this sense, we present an exact analysis free from approximation for the first time. After comparing our results against the closest early analysis, we discovered a major difference in resulted constraints on some ${\mu_i^*} {B_j}$ combinations. Constraints from neutrino masses on the parameters were considered. Our result indicates that the branching ratio measurement on $\mu \to e \gamma$ down to $10^{-13}-10^{-14}$ and beyond, as targeted by the MEG experiment, has a chance of observing decay from the R-parity violating scenario.