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2302.02905
Amit Tiwari
Qaisar Shafi, Amit Tiwari and Cem Salih Un
Third family quasi-Yukawa unification: Higgsino dark matter, NLSP gluino and all that
The revised draft includes Higgsino dark matter solutions and other improvements. Neutralino mixing and RGE evolutions of Yukawa couplings are corrected
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We explore the implications of third family ($t-b-\tau$) quasi-Yukawa unification (QYU) for collider and dark matter (DM) searches within the framework of a supersymmetric $SU(4)_c \times SU(2)_L \times SU(2)_R$ model. The deviation from exact Yukawa unification is quantified through the relation $y_t : y_b : y_\tau = |1+C|:|1-C|:|1+3C|$, with $C$ being a real parameter ($|C| \leq 0.2$). We allow for the breaking of left-right symmetry both by the soft scalar and gaugino mass parameters and obtain a variety of viable solutions that predict the sparticle mass spectrum including LSP DM (whose stability is guaranteed by a $Z_2$ gauge symmetry). We highlight solutions that include an NLSP gluino with mass $\sim$ 1.3-2.5 TeV, which should be accessible at LHC Run 3. There also exist NSLP stop solutions with masses heavier than about 1.8 TeV, which are consistent with the LSP neutralino dark matter relic density through stop-neutralino coannihilation. We identify A-resonance solutions with DM mass $\sim$ 0.8 - 2 TeV, as well as bino-chargino, bino-slepton and bino-stau co-annihilation scenarios. Finally, we also identify Wino-like ($\sim99\%$) and Higgsino-like ($\sim99\%$) solutions whose masses are heavier than about 1.5 TeV and 1 TeV, respectively. These solutions are compatible with the desired dark matter relic density and testable in ongoing and future direct detection experiments.
[ { "created": "Mon, 6 Feb 2023 16:21:23 GMT", "version": "v1" }, { "created": "Fri, 17 Mar 2023 00:32:41 GMT", "version": "v2" } ]
2023-03-20
[ [ "Shafi", "Qaisar", "" ], [ "Tiwari", "Amit", "" ], [ "Un", "Cem Salih", "" ] ]
We explore the implications of third family ($t-b-\tau$) quasi-Yukawa unification (QYU) for collider and dark matter (DM) searches within the framework of a supersymmetric $SU(4)_c \times SU(2)_L \times SU(2)_R$ model. The deviation from exact Yukawa unification is quantified through the relation $y_t : y_b : y_\tau = |1+C|:|1-C|:|1+3C|$, with $C$ being a real parameter ($|C| \leq 0.2$). We allow for the breaking of left-right symmetry both by the soft scalar and gaugino mass parameters and obtain a variety of viable solutions that predict the sparticle mass spectrum including LSP DM (whose stability is guaranteed by a $Z_2$ gauge symmetry). We highlight solutions that include an NLSP gluino with mass $\sim$ 1.3-2.5 TeV, which should be accessible at LHC Run 3. There also exist NSLP stop solutions with masses heavier than about 1.8 TeV, which are consistent with the LSP neutralino dark matter relic density through stop-neutralino coannihilation. We identify A-resonance solutions with DM mass $\sim$ 0.8 - 2 TeV, as well as bino-chargino, bino-slepton and bino-stau co-annihilation scenarios. Finally, we also identify Wino-like ($\sim99\%$) and Higgsino-like ($\sim99\%$) solutions whose masses are heavier than about 1.5 TeV and 1 TeV, respectively. These solutions are compatible with the desired dark matter relic density and testable in ongoing and future direct detection experiments.
1112.5339
Henrik Melbeus
Mattias Blennow, Henrik Melbeus, Tommy Ohlsson, He Zhang
RG running in a minimal UED model in light of recent LHC Higgs mass bounds
16 pages, 6 figures, RevTeX4. Final version published in Phys. Lett. B
Phys. Lett. B 712 (2012) 419-424
10.1016/j.physletb.2012.05.029
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study how the recent ATLAS and CMS Higgs mass bounds affect the renormalization group running of the physical parameters in universal extra dimensions. Using the running of the Higgs self-coupling constant, we derive bounds on the cutoff scale of the extra-dimensional theory itself. We show that the running of physical parameters, such as the fermion masses and the CKM mixing matrix, is significantly restricted by these bounds. In particular, we find that the running of the gauge couplings cannot be sufficient to allow gauge unification at the cutoff scale.
[ { "created": "Thu, 22 Dec 2011 14:57:22 GMT", "version": "v1" }, { "created": "Tue, 29 May 2012 11:43:55 GMT", "version": "v2" } ]
2015-06-03
[ [ "Blennow", "Mattias", "" ], [ "Melbeus", "Henrik", "" ], [ "Ohlsson", "Tommy", "" ], [ "Zhang", "He", "" ] ]
We study how the recent ATLAS and CMS Higgs mass bounds affect the renormalization group running of the physical parameters in universal extra dimensions. Using the running of the Higgs self-coupling constant, we derive bounds on the cutoff scale of the extra-dimensional theory itself. We show that the running of physical parameters, such as the fermion masses and the CKM mixing matrix, is significantly restricted by these bounds. In particular, we find that the running of the gauge couplings cannot be sufficient to allow gauge unification at the cutoff scale.
0812.2051
Linda Carpenter
Linda M. Carpenter
Surveying the Phenomenology of General Gauge Mediation
21 pages, 3 figures
null
null
SCIPP 08/13
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I explore the phenomenology, constraints and tuning for several weakly coupled implementations of multi-parameter gauge mediation and compare to minimal gauge mediation. The low energy spectra are distinct from that of minimal gauge mediation, a wide range of NLSPs is found and spectra are significantly compressed thus tunings may be generically reduced to a part in 10 to a part in 20.
[ { "created": "Thu, 11 Dec 2008 11:49:08 GMT", "version": "v1" } ]
2008-12-12
[ [ "Carpenter", "Linda M.", "" ] ]
I explore the phenomenology, constraints and tuning for several weakly coupled implementations of multi-parameter gauge mediation and compare to minimal gauge mediation. The low energy spectra are distinct from that of minimal gauge mediation, a wide range of NLSPs is found and spectra are significantly compressed thus tunings may be generically reduced to a part in 10 to a part in 20.
hep-ph/0409102
Atsushi Hosaka
A. Hosaka, M. Oka and T. Shinozaki
Decay of Theta+ in a quark model
14 pages, to appear in Phys. Rev. D
Phys.Rev. D71 (2005) 074021
10.1103/PhysRevD.71.074021
RCNP-Th04028
hep-ph
null
We study the decay of Theta+ in a non-relativistic quark model. The wave function of Theta+ is constructed for the two cases JP = 1/2+- as products of color, spin, flavor and orbital parts respecting total antisymmetrization among the four quarks. We find that for the negative parity Theta+ the width becomes very large which is of order of several hundreds MeV, while it is about a several tens MeV for the positive parity. By assuming additionally diquark correlations, the width is reduced to be of order 10 MeV. It is also pointed out that a similar calculation for 3/2- results in strong suppression of its width.
[ { "created": "Thu, 9 Sep 2004 03:21:54 GMT", "version": "v1" }, { "created": "Sat, 9 Apr 2005 12:32:51 GMT", "version": "v2" } ]
2009-11-10
[ [ "Hosaka", "A.", "" ], [ "Oka", "M.", "" ], [ "Shinozaki", "T.", "" ] ]
We study the decay of Theta+ in a non-relativistic quark model. The wave function of Theta+ is constructed for the two cases JP = 1/2+- as products of color, spin, flavor and orbital parts respecting total antisymmetrization among the four quarks. We find that for the negative parity Theta+ the width becomes very large which is of order of several hundreds MeV, while it is about a several tens MeV for the positive parity. By assuming additionally diquark correlations, the width is reduced to be of order 10 MeV. It is also pointed out that a similar calculation for 3/2- results in strong suppression of its width.
0806.0889
Wei Chao
Wei Chao
The Muon Magnetic Moment in the TeV Scale Seesaw Models
12 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The reported discrepancy of the muon abnormal magnetic moment $a_\mu^{}$ has impacts on the low energy phenomenology. In this paper we calculate the corrections to $a_\mu$ in the standard model extended by the TeV scale seesaw models. We show that the correction induced by the type-I seesaw model is negative and of the order ${\cal O} (10^{-11})$, which can be neglected compared with $a_\mu^{\rm SM}$. The correction induced by the type-II seesaw model, which depends on the mass of the Higgs triplet $m_\Delta$ and the Yukawa coupling $Y_\Delta$, can be of the order ${\cal O}(10^{-10})$ and compensate for the discrepancy between $a_\mu^{\rm SM}$ and $a_{\mu}^{\rm exp}$. The correction induced by the type-III seesaw model is also negative and can be of the order ${\cal O}(10^{-10})$.
[ { "created": "Thu, 5 Jun 2008 02:48:28 GMT", "version": "v1" } ]
2008-06-06
[ [ "Chao", "Wei", "" ] ]
The reported discrepancy of the muon abnormal magnetic moment $a_\mu^{}$ has impacts on the low energy phenomenology. In this paper we calculate the corrections to $a_\mu$ in the standard model extended by the TeV scale seesaw models. We show that the correction induced by the type-I seesaw model is negative and of the order ${\cal O} (10^{-11})$, which can be neglected compared with $a_\mu^{\rm SM}$. The correction induced by the type-II seesaw model, which depends on the mass of the Higgs triplet $m_\Delta$ and the Yukawa coupling $Y_\Delta$, can be of the order ${\cal O}(10^{-10})$ and compensate for the discrepancy between $a_\mu^{\rm SM}$ and $a_{\mu}^{\rm exp}$. The correction induced by the type-III seesaw model is also negative and can be of the order ${\cal O}(10^{-10})$.
hep-ph/0412054
Keith Olive
Keith A. Olive
Dark Matter Candidates in Supersymmetric Models
22 pages, 23 eps figures, Summary of talk at "Dark 2004", proceedings of 5th International Heidelberg Conference on Dark Matter in Astro and Particle Physics
null
null
UMN-TH-2332/04, FTPI-MINN-04/45
hep-ph
null
The status of the constrained minimal supersymmetric standard model (CMSSM) will be discussed in light of our current understanding of the relic density after WMAP. A global likelihood analysis of the model is performed including data from direct Higgs searches, global fits to electroweak data, b to s gamma, the anomalous magnetic moment of the muon, as well as the cosmological relic density. Also considered are models which relax and further constrain the CMSSM. Prospects for dark matter detection in colliders and cryogenic detectors will be briefly discussed.
[ { "created": "Fri, 3 Dec 2004 18:12:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Olive", "Keith A.", "" ] ]
The status of the constrained minimal supersymmetric standard model (CMSSM) will be discussed in light of our current understanding of the relic density after WMAP. A global likelihood analysis of the model is performed including data from direct Higgs searches, global fits to electroweak data, b to s gamma, the anomalous magnetic moment of the muon, as well as the cosmological relic density. Also considered are models which relax and further constrain the CMSSM. Prospects for dark matter detection in colliders and cryogenic detectors will be briefly discussed.
hep-ph/9208229
Ernest Ma
T. V. Duong and Ernest Ma
Decay of the Z Boson into Scalar Particles
11 pages (2 figures, not included) (Revised, Oct 1992). Some equations have been corrected and 1 figure has been eliminated
Phys.Rev. D47 (1993) 2020-2024
10.1103/PhysRevD.47.2020
UCRHEP-T96
hep-ph
null
In extensions of the standard model, light scalar particles are often possible because of symmetry considerations. We study the decay of the Z boson into such particles. In particular, we consider for illustration the scalar sector of a recently proposed model of the 17-keV neutrino which satisfies all laboratory, astrophysical, and cosmological constraints.
[ { "created": "Mon, 17 Aug 1992 18:50:46 GMT", "version": "v1" }, { "created": "Thu, 8 Oct 1992 15:53:37 GMT", "version": "v2" } ]
2009-10-22
[ [ "Duong", "T. V.", "" ], [ "Ma", "Ernest", "" ] ]
In extensions of the standard model, light scalar particles are often possible because of symmetry considerations. We study the decay of the Z boson into such particles. In particular, we consider for illustration the scalar sector of a recently proposed model of the 17-keV neutrino which satisfies all laboratory, astrophysical, and cosmological constraints.
hep-ph/0506198
Bibhuti Bhusan Deo
B. B. Deo, P. K. Mishra
Calculation of the Masses and the Running Masses of the Quarks and Leptons from Electroweak to Supersymmetric Grand Unification Mass
18 pages, 5 figures
null
null
null
hep-ph
null
We make a systematic theoretical analysis of the masses and their variation with energy by solving the renormalization group equation (RGE) in the Minimal Supersymmetric Standard Model (MSSM). The unification fermion masses of around 115 GeV at GeV scale has been derived by Deo and Maharana. Here we undertake the unfinished but the important task of calculating the masses and their running. The unification mass and group theoretic constants for the model are known. The top mass and its descent is studied very carefully. We find that the Ramond,Roberts and Ross value of the Wolfenstein parameter is nearly equal to 0.22. When raised to integral powers, the whole mass spectra of the remaining eleven fermions are obtained. We deduce formulas and plot them for all the 12 fermions as they vary from $t=log \frac{\mu}{M_z}=0$ to $t_X=33$; the GUT mass being $M_X=2.2\times 10^{16}$ GeV.
[ { "created": "Mon, 20 Jun 2005 20:11:04 GMT", "version": "v1" }, { "created": "Sun, 26 Jun 2005 06:57:11 GMT", "version": "v2" }, { "created": "Mon, 8 Aug 2005 08:40:53 GMT", "version": "v3" }, { "created": "Thu, 19 Jan 2006 07:05:33 GMT", "version": "v4" } ]
2007-05-23
[ [ "Deo", "B. B.", "" ], [ "Mishra", "P. K.", "" ] ]
We make a systematic theoretical analysis of the masses and their variation with energy by solving the renormalization group equation (RGE) in the Minimal Supersymmetric Standard Model (MSSM). The unification fermion masses of around 115 GeV at GeV scale has been derived by Deo and Maharana. Here we undertake the unfinished but the important task of calculating the masses and their running. The unification mass and group theoretic constants for the model are known. The top mass and its descent is studied very carefully. We find that the Ramond,Roberts and Ross value of the Wolfenstein parameter is nearly equal to 0.22. When raised to integral powers, the whole mass spectra of the remaining eleven fermions are obtained. We deduce formulas and plot them for all the 12 fermions as they vary from $t=log \frac{\mu}{M_z}=0$ to $t_X=33$; the GUT mass being $M_X=2.2\times 10^{16}$ GeV.
hep-ph/0508207
Jitesh Bhatt
Jitesh Bhatt and Raghavan Rangarajan
Thermalisation in Thick Wall Electroweak Baryogenesis
Final version published Physical Review D75, 087305, 2007 Significant changes from the previous version. (4pages no figures)
Phys.Rev.D75:087305,2007
10.1103/PhysRevD.75.087305
null
hep-ph
null
In models of thick wall electroweak baryogenesis a common assumption is that the plasma interacting with the expanding Higgs bubble wall during the electroweak phase transition is in kinetic equilibrium (or close to it). We point out that, in addition to the requirement of low wall velocity, kinetic equilibrium requires that the change in the momentum of the particles due to the force exerted by the wall should be much less than that due to scattering as the plasma passes through the wall. We investigate whether this condition is satisfied for charginos and neutralinos participating in thick wall supersymmetric electroweak baryogenesis
[ { "created": "Fri, 19 Aug 2005 06:29:15 GMT", "version": "v1" }, { "created": "Mon, 4 Jun 2007 11:01:40 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bhatt", "Jitesh", "" ], [ "Rangarajan", "Raghavan", "" ] ]
In models of thick wall electroweak baryogenesis a common assumption is that the plasma interacting with the expanding Higgs bubble wall during the electroweak phase transition is in kinetic equilibrium (or close to it). We point out that, in addition to the requirement of low wall velocity, kinetic equilibrium requires that the change in the momentum of the particles due to the force exerted by the wall should be much less than that due to scattering as the plasma passes through the wall. We investigate whether this condition is satisfied for charginos and neutralinos participating in thick wall supersymmetric electroweak baryogenesis
1407.8332
Marek Tasevsky
Marek Tasevsky
Review of Central Exclusive Production of the Higgs Boson Beyond the Standard Model
19 pages, 3 figures; to appear as review article in Int J Mod Phys A
null
10.1142/S0217751X14460129
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review activities in the field of theoretical, phenomenological and experimental studies related to the production of the Higgs boson in central exclusive processes at LHC in models beyond Standard Model. Prospects in the context of the Higgs boson discovery at LHC in 2012 and of proposals to build forward proton detectors at ATLAS and CMS side are summarized.
[ { "created": "Thu, 31 Jul 2014 09:49:00 GMT", "version": "v1" } ]
2015-06-22
[ [ "Tasevsky", "Marek", "" ] ]
We review activities in the field of theoretical, phenomenological and experimental studies related to the production of the Higgs boson in central exclusive processes at LHC in models beyond Standard Model. Prospects in the context of the Higgs boson discovery at LHC in 2012 and of proposals to build forward proton detectors at ATLAS and CMS side are summarized.
hep-ph/9808399
Zhen Cao
Zhen Cao and Rudolph C. Hwa
A Color Mutation Model of Soft Interaction in High Energy Hadronic Collisions
24 pages including 11 figures in revtex epsf style
Phys.Rev. D59 (1999) 114023
10.1103/PhysRevD.59.114023
OITS-645
hep-ph nucl-th
null
A comprehensive model, called ECOMB, is proposed to describe multiparticle production by soft interaction. It incorporates the eikonal formalism, parton model, color mutation, branching and recombination. The physics is conceptually opposite to the dynamics that underlies the fragmentation of a string. The partons are present initially in a hadronic collision; they form a single, large, color-neutral cluster until color mutation of the quarks leads to a fission of the cluster into two color-neutral subclusters. The mutation and branching processes continue until only $q\bar q$ pairs are left in each small cluster. The model contains self-similar dynamics and exhibits scaling behavior in the factorial moments. It can satisfactorily reproduce the intermittency data that no other model has been able to fit.
[ { "created": "Mon, 24 Aug 1998 16:50:12 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cao", "Zhen", "" ], [ "Hwa", "Rudolph C.", "" ] ]
A comprehensive model, called ECOMB, is proposed to describe multiparticle production by soft interaction. It incorporates the eikonal formalism, parton model, color mutation, branching and recombination. The physics is conceptually opposite to the dynamics that underlies the fragmentation of a string. The partons are present initially in a hadronic collision; they form a single, large, color-neutral cluster until color mutation of the quarks leads to a fission of the cluster into two color-neutral subclusters. The mutation and branching processes continue until only $q\bar q$ pairs are left in each small cluster. The model contains self-similar dynamics and exhibits scaling behavior in the factorial moments. It can satisfactorily reproduce the intermittency data that no other model has been able to fit.
hep-ph/9703271
Leonid Burakovsky
L. Burakovsky and T. Goldman
Towards resolution of the enigmas of P-wave meson spectroscopy
22 pages, LaTeX
Phys.Rev.D57:2879-2888,1998
10.1103/PhysRevD.57.2879
LA-UR-97-717
hep-ph
null
The mass spectrum of P-wave mesons is considered in a nonrelativistic constituent quark model. The results show the common mass degeneracy of the isovector and isodoublet states of the scalar and tensor meson nonets, and do not exclude the possibility of a similar degeneracy of the same states of the axial-vector and pseudovector nonets. Current experimental hadronic and \tau -decay data suggest, however, a different scenario leading to the a_1 meson mass \simeq 1190 MeV and the K_{1A}-K_{1B} mixing angle \simeq (37\pm 3)^o. Possible s\bar{s} states of the four nonets are also discussed.
[ { "created": "Sat, 8 Mar 1997 00:03:23 GMT", "version": "v1" }, { "created": "Wed, 7 May 1997 18:51:58 GMT", "version": "v2" } ]
2008-11-26
[ [ "Burakovsky", "L.", "" ], [ "Goldman", "T.", "" ] ]
The mass spectrum of P-wave mesons is considered in a nonrelativistic constituent quark model. The results show the common mass degeneracy of the isovector and isodoublet states of the scalar and tensor meson nonets, and do not exclude the possibility of a similar degeneracy of the same states of the axial-vector and pseudovector nonets. Current experimental hadronic and \tau -decay data suggest, however, a different scenario leading to the a_1 meson mass \simeq 1190 MeV and the K_{1A}-K_{1B} mixing angle \simeq (37\pm 3)^o. Possible s\bar{s} states of the four nonets are also discussed.
hep-ph/9606250
Ephraim Fischbach
Ephraim Fischbach
A Lower Bound on Neutrino Mass
4 pages; Moriond Proceedings
null
null
null
hep-ph
null
The exchange of massless neutrinos between heavy fermions (e.g. $e,p,n$) gives rise to a long-range 2-body force. It is shown that the analogous many-body force can lead to an unphysically large energy density in white dwarfs and neutron stars. To reduce the energy density to a physically acceptable value, the neutrino must have a {\it minimum mass}, which is approximately $0.4\;eV/c^2$. Some recent questions relating to the derivation of this bound are also discussed.
[ { "created": "Wed, 5 Jun 1996 19:20:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fischbach", "Ephraim", "" ] ]
The exchange of massless neutrinos between heavy fermions (e.g. $e,p,n$) gives rise to a long-range 2-body force. It is shown that the analogous many-body force can lead to an unphysically large energy density in white dwarfs and neutron stars. To reduce the energy density to a physically acceptable value, the neutrino must have a {\it minimum mass}, which is approximately $0.4\;eV/c^2$. Some recent questions relating to the derivation of this bound are also discussed.
hep-ph/9910218
Silvano Simula
F. Cardarelli and S. Simula
Analysis of the exclusive semileptonic decay Lambda_b -> Lambda_c + l nu_l within a light-front constituent quark model
in Proceedings of the International Conference PANIC '99, Uppsala (Sweden), June 1999
Nucl.Phys. A663 (2000) 931-934
10.1016/S0375-9474(99)00800-3
preprint RM3-TH/99-10
hep-ph
null
The exclusive semileptonic decay Lambda_b -> Lambda_c + l nu_l is investigated including both radiative and first-order power corrections in the inverse heavy-quark mass, while the Isgur-Wise function is calculated within a light-front constituent quark model. It turns out that the dependence on the model parameters can be effectively constrained using recent lattice QCD results at low values of the recoil. Our final predictions for the exclusive semileptonic branching ratio, the longitudinal and transverse asymmetries, and the longitudinal to transverse decay ratio are: Br(Lambda_b -> Lambda_c + l nu_l) = (6.3 \pm 1.6) % |V_{bc} / 0.040|**2 \tau(\Lambda_b) / (1.24 ps), a_L = -0.945 \pm 0.014, a_T = -0.62 \pm 0.09 and R_L/T = 1.57 \pm 0.15, respectively. Moreover, the theoretical uncertainties both on a_L and the (partially integrated) R_L/T are found to be quite small and, therefore, the experimental determination of these quantities is a very interesting tool for testing the Standard Model and for investigating possible New Physics. In this respect the sensitivity to extract unique information both on the strength and phase of possible hadronic right-handed currents is illustrated.
[ { "created": "Mon, 4 Oct 1999 10:36:04 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cardarelli", "F.", "" ], [ "Simula", "S.", "" ] ]
The exclusive semileptonic decay Lambda_b -> Lambda_c + l nu_l is investigated including both radiative and first-order power corrections in the inverse heavy-quark mass, while the Isgur-Wise function is calculated within a light-front constituent quark model. It turns out that the dependence on the model parameters can be effectively constrained using recent lattice QCD results at low values of the recoil. Our final predictions for the exclusive semileptonic branching ratio, the longitudinal and transverse asymmetries, and the longitudinal to transverse decay ratio are: Br(Lambda_b -> Lambda_c + l nu_l) = (6.3 \pm 1.6) % |V_{bc} / 0.040|**2 \tau(\Lambda_b) / (1.24 ps), a_L = -0.945 \pm 0.014, a_T = -0.62 \pm 0.09 and R_L/T = 1.57 \pm 0.15, respectively. Moreover, the theoretical uncertainties both on a_L and the (partially integrated) R_L/T are found to be quite small and, therefore, the experimental determination of these quantities is a very interesting tool for testing the Standard Model and for investigating possible New Physics. In this respect the sensitivity to extract unique information both on the strength and phase of possible hadronic right-handed currents is illustrated.
2109.10414
Anja Butter
Anja Butter, Tilman Plehn, Nathalie Soybelman, and Johann Brehmer
Back to the Formula -- LHC Edition
null
SciPost Phys. 16, 037 (2024)
10.21468/SciPostPhys.16.1.037
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
While neural networks offer an attractive way to numerically encode functions, actual formulas remain the language of theoretical particle physics. We show how symbolic regression trained on matrix-element information provides, for instance, optimal LHC observables in an easily interpretable form. We introduce the method using the effect of a dimension-6 coefficient on associated ZH production. We then validate it for the known case of CP-violation in weak-boson-fusion Higgs production, including detector effects.
[ { "created": "Tue, 21 Sep 2021 19:38:27 GMT", "version": "v1" }, { "created": "Mon, 15 Nov 2021 08:58:45 GMT", "version": "v2" }, { "created": "Tue, 31 Jan 2023 09:14:32 GMT", "version": "v3" } ]
2024-01-31
[ [ "Butter", "Anja", "" ], [ "Plehn", "Tilman", "" ], [ "Soybelman", "Nathalie", "" ], [ "Brehmer", "Johann", "" ] ]
While neural networks offer an attractive way to numerically encode functions, actual formulas remain the language of theoretical particle physics. We show how symbolic regression trained on matrix-element information provides, for instance, optimal LHC observables in an easily interpretable form. We introduce the method using the effect of a dimension-6 coefficient on associated ZH production. We then validate it for the known case of CP-violation in weak-boson-fusion Higgs production, including detector effects.
hep-ph/9906233
null
Howard Baer, Manuel Drees, Frank Paige, Pamela Quintana and Xerxes Tata
Trilepton Signal for Supersymmetry at the Fermilab Tevatron Revisited
final version to coincide with published manuscript
Phys.Rev. D61 (2000) 095007
10.1103/PhysRevD.61.095007
FSU-HEP-990509, IFT-P.041/99, BNL-HET-99/12, UH-511-933-99
hep-ph
null
Within a wide class of models, the LEP2 lower limit of 95 GeV on the chargino mass implies gluinos are heavier than $\sim$300 GeV. In this case electroweak $\tw_1\twb_1$ and $\tw_1\tz_2$ production are the dominant SUSY processes at the Tevatron, and the extensively examined isolated trilepton signal from $\tw_1\tz_2$ production assumes an even greater importance. We update our previous calculations of the SUSY reach of luminosity upgrades of the Fermilab Tevatron in this channel incorporating ({\it i}) decay matrix elements in the computation of the momenta of leptons from chargino and neutralino decays, ({\it ii}) the trilepton background from $W^*Z^*$ and $W^*\gamma^*$ production which, though neglected in previous analyses, turns out to be the dominant background, and finally, ({\it iii}) modified sets of cuts designed to reduce these new backgrounds and increase the range of model parameters for which the signal is observable. We show our improved projections for the reach for SUSY of both the Fermilab Main Injector and the proposed TeV33 upgrade. We also present opposite sign same flavor dilepton invariant mass distributions as well as the $p_T$ distributions of leptons in SUSY trilepton events, and comment upon how the inclusion of decay matrix elements impacts upon the Tevatron reach, as well as upon the extraction of neutralino masses.
[ { "created": "Thu, 3 Jun 1999 14:15:49 GMT", "version": "v1" }, { "created": "Thu, 8 Jul 1999 19:30:29 GMT", "version": "v2" }, { "created": "Thu, 6 Apr 2000 21:01:02 GMT", "version": "v3" } ]
2016-09-06
[ [ "Baer", "Howard", "" ], [ "Drees", "Manuel", "" ], [ "Paige", "Frank", "" ], [ "Quintana", "Pamela", "" ], [ "Tata", "Xerxes", "" ] ]
Within a wide class of models, the LEP2 lower limit of 95 GeV on the chargino mass implies gluinos are heavier than $\sim$300 GeV. In this case electroweak $\tw_1\twb_1$ and $\tw_1\tz_2$ production are the dominant SUSY processes at the Tevatron, and the extensively examined isolated trilepton signal from $\tw_1\tz_2$ production assumes an even greater importance. We update our previous calculations of the SUSY reach of luminosity upgrades of the Fermilab Tevatron in this channel incorporating ({\it i}) decay matrix elements in the computation of the momenta of leptons from chargino and neutralino decays, ({\it ii}) the trilepton background from $W^*Z^*$ and $W^*\gamma^*$ production which, though neglected in previous analyses, turns out to be the dominant background, and finally, ({\it iii}) modified sets of cuts designed to reduce these new backgrounds and increase the range of model parameters for which the signal is observable. We show our improved projections for the reach for SUSY of both the Fermilab Main Injector and the proposed TeV33 upgrade. We also present opposite sign same flavor dilepton invariant mass distributions as well as the $p_T$ distributions of leptons in SUSY trilepton events, and comment upon how the inclusion of decay matrix elements impacts upon the Tevatron reach, as well as upon the extraction of neutralino masses.
hep-ph/9702379
Wally Melnitchouk
Xiangdong Ji, W. Melnitchouk (U. Maryland) and X. Song (U. Virginia)
A Study of Off-Forward Parton Distributions
29 pages revtex, 12 postscript figures, minor corrections, references updated
Phys.Rev. D56 (1997) 5511-5523
10.1103/PhysRevD.56.5511
UMD PP 97-085, INPP-UVA-97-01
hep-ph nucl-th
null
An extensive theoretical analysis of off-forward parton distributions (OFPDs) is presented. The OFPDs and the form factors of the quark energy-momentum tensor are estimated at a low-energy scale using a bag model. Relations among the second moments of OFPDs, the form factors, and the fraction of the nucleon spin carried by quarks are discussed.
[ { "created": "Fri, 21 Feb 1997 00:53:49 GMT", "version": "v1" }, { "created": "Thu, 27 Feb 1997 22:07:13 GMT", "version": "v2" } ]
2009-10-30
[ [ "Ji", "Xiangdong", "", "U. Maryland" ], [ "Melnitchouk", "W.", "", "U. Maryland" ], [ "Song", "X.", "", "U. Virginia" ] ]
An extensive theoretical analysis of off-forward parton distributions (OFPDs) is presented. The OFPDs and the form factors of the quark energy-momentum tensor are estimated at a low-energy scale using a bag model. Relations among the second moments of OFPDs, the form factors, and the fraction of the nucleon spin carried by quarks are discussed.
hep-ph/0412424
James Wells
Stephen P. Martin, Kazuhiro Tobe, James D. Wells
Virtual effects of light gauginos and higgsinos: a precision electroweak analysis of split supersymmetry
22 pages, 5 figures, v2: typos fixed and note added
Phys.Rev. D71 (2005) 073014
10.1103/PhysRevD.71.073014
null
hep-ph
null
We compute corrections to precision electroweak observables in supersymmetry in the limit that scalar superpartners are very massive and decoupled. This leaves charginos and neutralinos and a Standard Model-like Higgs boson as the only states with unknown mass substantially affecting the analysis. We give complete formulas for the chargino and neutralino contributions, derive simple analytic results for the pure gaugino and higgsino cases, and study the general case. We find that in all circumstances, the precision electroweak fit improves when the charginos and neutralinos are near the current direct limits. Larger higgsino and gaugino masses worsen the fit as the theory predictions asymptotically approach those of the Standard Model. Since the Standard Model is considered by most to be an adequate fit to the precision electroweak data, an important corollary to our analysis is that all regions of parameter space allowed by direct collider constraints are also allowed by precision electroweak constraints in split supersymmetry.
[ { "created": "Thu, 30 Dec 2004 19:55:03 GMT", "version": "v1" }, { "created": "Wed, 20 Apr 2005 18:28:28 GMT", "version": "v2" } ]
2009-11-10
[ [ "Martin", "Stephen P.", "" ], [ "Tobe", "Kazuhiro", "" ], [ "Wells", "James D.", "" ] ]
We compute corrections to precision electroweak observables in supersymmetry in the limit that scalar superpartners are very massive and decoupled. This leaves charginos and neutralinos and a Standard Model-like Higgs boson as the only states with unknown mass substantially affecting the analysis. We give complete formulas for the chargino and neutralino contributions, derive simple analytic results for the pure gaugino and higgsino cases, and study the general case. We find that in all circumstances, the precision electroweak fit improves when the charginos and neutralinos are near the current direct limits. Larger higgsino and gaugino masses worsen the fit as the theory predictions asymptotically approach those of the Standard Model. Since the Standard Model is considered by most to be an adequate fit to the precision electroweak data, an important corollary to our analysis is that all regions of parameter space allowed by direct collider constraints are also allowed by precision electroweak constraints in split supersymmetry.
hep-ph/9712298
Martin Beneke
M. Beneke (CERN)
Quarkonium polarization as a test of non-relativistic effective theory
6 pages, LaTeX, 3 figures included via epsf.sty, uses sprocl.sty (provided)
null
null
CERN-TH/97-355
hep-ph
null
I compare current approaches to quarkonium production with regard to what they tell us about quarkonium polarization. Predictions for $J/\psi$ polarization in hadron-hadron and photon-hadron collisions are summarized.
[ { "created": "Mon, 8 Dec 1997 15:00:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Beneke", "M.", "", "CERN" ] ]
I compare current approaches to quarkonium production with regard to what they tell us about quarkonium polarization. Predictions for $J/\psi$ polarization in hadron-hadron and photon-hadron collisions are summarized.
2112.09867
Samadrita Mukherjee
Md. Isha Ali, Manimala Chakraborti, Utpal Chattopadhyay, Samadrita Mukherjee
Muon and Electron $(g-2)$ Anomalies with Non-Holomorphic Interactions in MSSM
Some changes in the texts and in a few figures, results and conclusion unchanged, accepted in EPJC
The European Physical Journal C volume 83, Article number: 60 (2023)
10.1140/epjc/s10052-023-11216-4
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The recent Fermilab muon $g-2$ result and the same for electron due to fine-structure constant measurement through ${}^{133}{\rm Cs}$ matter-wave interferometry are probed in relation to MSSM with non-holomorphic (NH) trilinear soft SUSY breaking terms, referred as NHSSM. Supersymmetric contributions to charged lepton $(g-2)_l$ can be enhanced via the new trilinear terms involving a wrong Higgs coupling with left and right-handed scalars. Unlike many MSSM based analyses, the model does not require a light electroweakino, or light sleptons, or unequal left and right slepton masses, or a very large higgsino mass parameter. The first part of the analysis involves $(g-2)_\mu$ constraint along with limits from Higgs mass, B-physics, collider data, direct detection of dark matter (DM) while focusing on a higgsino DM which is underabundant in nature. We then impose the constraint from electron $g-2$ where a large Yukawa threshold corrections (an outcome of NHSSM) and opposite signs of trilinear NH coefficients associated with $\mu$ and $e$ fields are used to satisfy the dual limits of $\Delta {a_\mu}$ and $\Delta {a_e}$ (where the latter comes with negative sign). Varying Yukawa threshold corrections further provide the necessary flavor-dependent enhancement of $\Delta {a_e}/m_e^2$ compared to that of $\Delta {a_\mu}/m_\mu^2$. A larger Yukawa threshold correction through $A^\prime_e$ for $y_e$ also takes away the direct proportionality of $a_e$ with respect to $\tan\beta$. With a finite intercept, $a_e$ becomes only an increasing function of $\tan\beta$. We identified the available parameter space in the two cases while also applying the ATLAS data on slepton pair production in the plane of slepton mass parameter and the mass of the lightest neutralino.
[ { "created": "Sat, 18 Dec 2021 07:44:43 GMT", "version": "v1" }, { "created": "Fri, 24 Jun 2022 15:04:06 GMT", "version": "v2" }, { "created": "Tue, 24 Jan 2023 06:10:00 GMT", "version": "v3" } ]
2023-01-25
[ [ "Ali", "Md. Isha", "" ], [ "Chakraborti", "Manimala", "" ], [ "Chattopadhyay", "Utpal", "" ], [ "Mukherjee", "Samadrita", "" ] ]
The recent Fermilab muon $g-2$ result and the same for electron due to fine-structure constant measurement through ${}^{133}{\rm Cs}$ matter-wave interferometry are probed in relation to MSSM with non-holomorphic (NH) trilinear soft SUSY breaking terms, referred as NHSSM. Supersymmetric contributions to charged lepton $(g-2)_l$ can be enhanced via the new trilinear terms involving a wrong Higgs coupling with left and right-handed scalars. Unlike many MSSM based analyses, the model does not require a light electroweakino, or light sleptons, or unequal left and right slepton masses, or a very large higgsino mass parameter. The first part of the analysis involves $(g-2)_\mu$ constraint along with limits from Higgs mass, B-physics, collider data, direct detection of dark matter (DM) while focusing on a higgsino DM which is underabundant in nature. We then impose the constraint from electron $g-2$ where a large Yukawa threshold corrections (an outcome of NHSSM) and opposite signs of trilinear NH coefficients associated with $\mu$ and $e$ fields are used to satisfy the dual limits of $\Delta {a_\mu}$ and $\Delta {a_e}$ (where the latter comes with negative sign). Varying Yukawa threshold corrections further provide the necessary flavor-dependent enhancement of $\Delta {a_e}/m_e^2$ compared to that of $\Delta {a_\mu}/m_\mu^2$. A larger Yukawa threshold correction through $A^\prime_e$ for $y_e$ also takes away the direct proportionality of $a_e$ with respect to $\tan\beta$. With a finite intercept, $a_e$ becomes only an increasing function of $\tan\beta$. We identified the available parameter space in the two cases while also applying the ATLAS data on slepton pair production in the plane of slepton mass parameter and the mass of the lightest neutralino.
hep-ph/0605246
Fran\c{c}ois Gelis
Francois Gelis, Raju Venugopalan
Particle production in field theories coupled to strong external sources. II: Generating functions
24 pages, 6 figures, version to appear in NPA
Nucl.Phys. A779 (2006) 177-196
10.1016/j.nuclphysa.2006.08.015
null
hep-ph hep-th nucl-ex nucl-th
null
We discuss a method for computing the generating function for the multiplicity distribution in field theories with strong time dependent external sources. At leading order, the computation of the generating function reduces to finding a pair of solutions of the classical equations of motion, with non-standard temporal boundary conditions.
[ { "created": "Tue, 23 May 2006 14:43:19 GMT", "version": "v1" }, { "created": "Mon, 2 Oct 2006 08:42:19 GMT", "version": "v2" } ]
2009-11-11
[ [ "Gelis", "Francois", "" ], [ "Venugopalan", "Raju", "" ] ]
We discuss a method for computing the generating function for the multiplicity distribution in field theories with strong time dependent external sources. At leading order, the computation of the generating function reduces to finding a pair of solutions of the classical equations of motion, with non-standard temporal boundary conditions.
hep-ph/0105104
Kristof Redlich
Krzysztof Redlich
Strangeness production in heavy ion collisions
10 pages, 14 figures, Plenary talk given at 15th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (QM2001), Stony Brook, New York, 15-20 Jan 2001
Nucl.Phys. A698 (2002) 94-103
10.1016/S0375-9474(01)01352-5
GSI-Preprint-2001-14
hep-ph
null
Strangeness production in heavy ion collisions is discussed in a broad energy range from SIS to RHIC. %We emphasize that in the In the whole energy range particle yields are showing high level of chemical equilibration which can be described by the unified freezeout conditions of fixed energy/particle $\simeq 1$GeV. The statistical model within the canonical formulation of strangeness conservation provides a framework to describe the observed enhancement of (multi)strange particles from p+A to A+A collisions measured at the SPS energy and predicts that this enhancement should be larger for decreasing collision energy. However, only at the SPS and RHIC chemical freezeout temperature is consistent within error with the critical value required for deconfinement and simultaneously strangeness is uncorrelated and distributed in the whole volume of the fireball.
[ { "created": "Fri, 11 May 2001 18:11:08 GMT", "version": "v1" } ]
2009-11-07
[ [ "Redlich", "Krzysztof", "" ] ]
Strangeness production in heavy ion collisions is discussed in a broad energy range from SIS to RHIC. %We emphasize that in the In the whole energy range particle yields are showing high level of chemical equilibration which can be described by the unified freezeout conditions of fixed energy/particle $\simeq 1$GeV. The statistical model within the canonical formulation of strangeness conservation provides a framework to describe the observed enhancement of (multi)strange particles from p+A to A+A collisions measured at the SPS energy and predicts that this enhancement should be larger for decreasing collision energy. However, only at the SPS and RHIC chemical freezeout temperature is consistent within error with the critical value required for deconfinement and simultaneously strangeness is uncorrelated and distributed in the whole volume of the fireball.
0809.4835
Zhang He
Tommy Ohlsson and He Zhang
Non-Standard Interaction Effects at Reactor Neutrino Experiments
17 pages, 5 figures, version to appear in PLB
Phys.Lett.B671:99-104,2009
10.1016/j.physletb.2008.12.005
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study non-standard interactions (NSIs) at reactor neutrino experiments, and in particular, the mimicking effects on \theta_13. We present generic formulas for oscillation probabilities including NSIs from sources and detectors. Instructive mappings between the fundamental leptonic mixing parameters and the effective leptonic mixing parameters are established. In addition, NSI corrections to the mixing angles \theta_13 and \theta_12 are discussed in detailed. Finally, we show that, even for a vanishing \theta_13, an oscillation phenomenon may still be observed in future short baseline reactor neutrino experiments, such as Double Chooz and Daya Bay, due to the existences of NSIs.
[ { "created": "Sun, 28 Sep 2008 10:46:47 GMT", "version": "v1" }, { "created": "Wed, 10 Dec 2008 09:17:48 GMT", "version": "v2" } ]
2009-01-16
[ [ "Ohlsson", "Tommy", "" ], [ "Zhang", "He", "" ] ]
We study non-standard interactions (NSIs) at reactor neutrino experiments, and in particular, the mimicking effects on \theta_13. We present generic formulas for oscillation probabilities including NSIs from sources and detectors. Instructive mappings between the fundamental leptonic mixing parameters and the effective leptonic mixing parameters are established. In addition, NSI corrections to the mixing angles \theta_13 and \theta_12 are discussed in detailed. Finally, we show that, even for a vanishing \theta_13, an oscillation phenomenon may still be observed in future short baseline reactor neutrino experiments, such as Double Chooz and Daya Bay, due to the existences of NSIs.
hep-ph/0306304
Thomas Kernreiter
A. Bartl, H. Fraas, T. Kernreiter, O. Kittel
T-odd Correlations in the Decay of Scalar Fermions
18 pages, 5 figures, 2 tables; comments and references added; two tables added; version to appear in Eur. Phys. J
Eur.Phys.J. C33 (2004) 433-442
10.1140/epjc/s2003-01521-9
null
hep-ph
null
We define a CP sensitive asymmetry in the sfermion decays $\ti f \to f \ti\chi^0_j \ell \bar \ell, f \ti\chi^0_j q \bar q$, based on triple product correlations between the momenta of the outgoing fermions. We study this asymmetry in the MSSM with complex parameters. We show that the asymmetry is sensitive to the phases of the parameters $\mu$ and $M_1$. The leading contribution stems from the decay chain $\ti f\to f \ti\chi^0_j\to f \ti\chi^0_1 Z\to f \ti\chi^0_1 \ell \bar \ell (f \ti\chi^0_1 q \bar q)$, for which we obtain analytic formulae for the amplitude squared. The asymmetry can go up to 3% for $\ti f\to f \ti\chi^0_1 \ell \bar \ell$, and up to 20% for $\ti f\to f \ti\chi^0_1 q \bar q$. We also estimate the rates necessary to measure the asymmetry.
[ { "created": "Mon, 30 Jun 2003 15:17:12 GMT", "version": "v1" }, { "created": "Fri, 21 Nov 2003 14:07:14 GMT", "version": "v2" } ]
2009-11-10
[ [ "Bartl", "A.", "" ], [ "Fraas", "H.", "" ], [ "Kernreiter", "T.", "" ], [ "Kittel", "O.", "" ] ]
We define a CP sensitive asymmetry in the sfermion decays $\ti f \to f \ti\chi^0_j \ell \bar \ell, f \ti\chi^0_j q \bar q$, based on triple product correlations between the momenta of the outgoing fermions. We study this asymmetry in the MSSM with complex parameters. We show that the asymmetry is sensitive to the phases of the parameters $\mu$ and $M_1$. The leading contribution stems from the decay chain $\ti f\to f \ti\chi^0_j\to f \ti\chi^0_1 Z\to f \ti\chi^0_1 \ell \bar \ell (f \ti\chi^0_1 q \bar q)$, for which we obtain analytic formulae for the amplitude squared. The asymmetry can go up to 3% for $\ti f\to f \ti\chi^0_1 \ell \bar \ell$, and up to 20% for $\ti f\to f \ti\chi^0_1 q \bar q$. We also estimate the rates necessary to measure the asymmetry.
hep-ph/0609180
Ayres Freitas
A. Freitas, P. Z. Skands
Testing the SUSY-QCD Yukawa coupling in a combined LHC/ILC analysis
5pp, slightly expanded version of contributions to the Proc. of the Linear Collider Workshop (LCWS 06), Bangalore, India, 9-13 March 2006, and the Proc. of the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY 06), Irvine, California, USA, 12-17 June 2006
Pramana 69:843-848,2007
10.1007/s12043-007-0193-3
FERMILAB-CONF-06-322-T
hep-ph
null
In order to establish supersymmetry (SUSY) at future colliders, the identity of gauge couplings and the corresponding Yukawa couplings between gauginos, sfermions and fermions needs to be verified. Here a first phenomenological study for determining the Yukawa coupling of the SUSY-QCD sector is presented, using a method which combines information from LHC and ILC.
[ { "created": "Tue, 19 Sep 2006 13:22:59 GMT", "version": "v1" } ]
2009-12-15
[ [ "Freitas", "A.", "" ], [ "Skands", "P. Z.", "" ] ]
In order to establish supersymmetry (SUSY) at future colliders, the identity of gauge couplings and the corresponding Yukawa couplings between gauginos, sfermions and fermions needs to be verified. Here a first phenomenological study for determining the Yukawa coupling of the SUSY-QCD sector is presented, using a method which combines information from LHC and ILC.
2301.11484
Fabian Rennecke
Fabian Rennecke, Robert D. Pisarski and Dirk H. Rischke
Particle Interferometry in a Moat Regime
14 pages, 8 figures
null
10.1103/PhysRevD.107.116011
null
hep-ph nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Dense strongly interacting matter can exhibit regimes with spatial modulations, akin to crystalline phases. In this case particles can have a moat spectrum with minimal energy at nonzero momentum. We show that particle interferometry is a sensitive probe of such a regime in heavy-ion collisions. To this end, we develop a field-theoretical formalism that relates particle spectra to in-medium real-time correlation functions of quantum fields on curved hypersurfaces of spacetime. This is then applied to the study of Bose-Einstein correlations in a moat regime in heavy-ion collisions. The resulting two-particle spectra exhibit peaks at nonzero average pair momentum, in contrast to the two-particle spectra in a normal phase, which peak at zero momentum. These peaks lead to non-trivial structures in the ratio of two-particle correlation functions, which should be experimentally measurable if the resolution in the direction of average pair momentum is sufficiently large. We propose these structures in the correlation-function ratios as clear signature of a moat regime and spatially modulated phases in quantum chromodynamics (QCD).
[ { "created": "Fri, 27 Jan 2023 01:26:45 GMT", "version": "v1" } ]
2023-06-21
[ [ "Rennecke", "Fabian", "" ], [ "Pisarski", "Robert D.", "" ], [ "Rischke", "Dirk H.", "" ] ]
Dense strongly interacting matter can exhibit regimes with spatial modulations, akin to crystalline phases. In this case particles can have a moat spectrum with minimal energy at nonzero momentum. We show that particle interferometry is a sensitive probe of such a regime in heavy-ion collisions. To this end, we develop a field-theoretical formalism that relates particle spectra to in-medium real-time correlation functions of quantum fields on curved hypersurfaces of spacetime. This is then applied to the study of Bose-Einstein correlations in a moat regime in heavy-ion collisions. The resulting two-particle spectra exhibit peaks at nonzero average pair momentum, in contrast to the two-particle spectra in a normal phase, which peak at zero momentum. These peaks lead to non-trivial structures in the ratio of two-particle correlation functions, which should be experimentally measurable if the resolution in the direction of average pair momentum is sufficiently large. We propose these structures in the correlation-function ratios as clear signature of a moat regime and spatially modulated phases in quantum chromodynamics (QCD).
0809.0710
Howard Baer
Howard Baer, Sabine Kraml, Sezen Sekmen, Heaya Summy
Prospects for Yukawa Unified SO(10) SUSY GUTs at the CERN LHC
25 pages including 18 EPS figures
JHEP 0810:079,2008
10.1088/1126-6708/2008/10/079
FSU-HEP-080822, LPSC 08-133
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The requirement of t-b-\tau Yukawa coupling unification is common in simple grand unified models based on the gauge group SO(10), and it also places a severe constraint on the expected spectrum of superpartners. For Yukawa-unified models with \mu >0, the spectrum is characterized by three mass scales: {\it i}). first and second generation scalars in the multi-TeV range, {\it ii}). third generation scalars, \mu and m_A in the few-TeV range and {\it iii}). gluinos in the \sim 350-500 GeV range with chargino masses around 100-160 GeV. In such a scenario, gluino pair production should occur at large rates at the CERN LHC, followed by gluino three-body decays into neutralinos or charginos. Discovery of Yukawa-unified SUSY at the LHC should hence be possible with only 1 fb^{-1} of integrated luminosity, by tagging multi-jet events with 2--3 isolated leptons, without relying on missing E_T. A characteristic dilepton mass edge should easily be apparent above Standard Model background. Combining dileptons with b-jets, along with the gluino pair production cross section information, should allow for gluino and neutralino mass reconstruction. A secondary corroborative signal should be visible at higher integrated luminosity in the W1Z2-> 3\ell channel, and should exhibit the same dilepton mass edge as in the gluino cascade decay signal.
[ { "created": "Wed, 3 Sep 2008 21:13:29 GMT", "version": "v1" } ]
2009-05-08
[ [ "Baer", "Howard", "" ], [ "Kraml", "Sabine", "" ], [ "Sekmen", "Sezen", "" ], [ "Summy", "Heaya", "" ] ]
The requirement of t-b-\tau Yukawa coupling unification is common in simple grand unified models based on the gauge group SO(10), and it also places a severe constraint on the expected spectrum of superpartners. For Yukawa-unified models with \mu >0, the spectrum is characterized by three mass scales: {\it i}). first and second generation scalars in the multi-TeV range, {\it ii}). third generation scalars, \mu and m_A in the few-TeV range and {\it iii}). gluinos in the \sim 350-500 GeV range with chargino masses around 100-160 GeV. In such a scenario, gluino pair production should occur at large rates at the CERN LHC, followed by gluino three-body decays into neutralinos or charginos. Discovery of Yukawa-unified SUSY at the LHC should hence be possible with only 1 fb^{-1} of integrated luminosity, by tagging multi-jet events with 2--3 isolated leptons, without relying on missing E_T. A characteristic dilepton mass edge should easily be apparent above Standard Model background. Combining dileptons with b-jets, along with the gluino pair production cross section information, should allow for gluino and neutralino mass reconstruction. A secondary corroborative signal should be visible at higher integrated luminosity in the W1Z2-> 3\ell channel, and should exhibit the same dilepton mass edge as in the gluino cascade decay signal.
1201.2085
Ernst Trojan
Ernst Trojan
Superluminal self-interacting neutrino
13 pages, no figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effect of nonlinear self-interaction can be associated with superluminal velocity of neutrino. The power energy spectrum E=p+Cp^a is derived from the nonlinear Dirac equation when interaction term V=\lambda (\psi \gamma_\mu \psi \psi \gamma^\mu \psi)^a is added to the Lagrangian of a free spin-1/2 particle. The superluminal velocity recorded by the OPERA and MINOS collaborations is achieved when the coupling constants are taken in the range a=0.4-1.18 and \lambda =-(0.5-1.6)x10^-4. The self-interaction Lagrangian V=\lambda (\psi \gamma_\mu \psi \psi \gamma ^\mu \psi) with the coupling constant \lambda =-(0.7-0.9)x10^-4 yields the same result. Scalar interaction V=\lambda (\psi \psi)^b and scalar-vector interaction \lambda(\psi^{+}\psi)^{b+1}/(\psi \psi)^b cannot be responsible for the observed superluminal neutrino.
[ { "created": "Mon, 9 Jan 2012 16:24:44 GMT", "version": "v1" } ]
2012-01-11
[ [ "Trojan", "Ernst", "" ] ]
The effect of nonlinear self-interaction can be associated with superluminal velocity of neutrino. The power energy spectrum E=p+Cp^a is derived from the nonlinear Dirac equation when interaction term V=\lambda (\psi \gamma_\mu \psi \psi \gamma^\mu \psi)^a is added to the Lagrangian of a free spin-1/2 particle. The superluminal velocity recorded by the OPERA and MINOS collaborations is achieved when the coupling constants are taken in the range a=0.4-1.18 and \lambda =-(0.5-1.6)x10^-4. The self-interaction Lagrangian V=\lambda (\psi \gamma_\mu \psi \psi \gamma ^\mu \psi) with the coupling constant \lambda =-(0.7-0.9)x10^-4 yields the same result. Scalar interaction V=\lambda (\psi \psi)^b and scalar-vector interaction \lambda(\psi^{+}\psi)^{b+1}/(\psi \psi)^b cannot be responsible for the observed superluminal neutrino.
1111.6576
Christian Spethmann
Christian Spethmann
Constraints on W Prime Models for the ttbar Asymmetry
Talk given at the SUSY 2011 conference. 5 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss if the Tevatron ttbar asymmetry can be explained by T-channel exchange of a W' gauge boson coupling to down and top quarks. In a spontaneously broken gauge theory, such a W' is necessarily accompanied by a Z' at a similar mass scale. Null results from Tevatron searches for dijet and dilepton resonances imply large mass splitting between the $W'$ and $Z'$. We argue that such splitting can only be accomplished if the gauge symmetry is broken by a scalar in a large dimension representation of the gauge group, for which no perturbative description exists.
[ { "created": "Mon, 28 Nov 2011 20:44:10 GMT", "version": "v1" } ]
2011-11-29
[ [ "Spethmann", "Christian", "" ] ]
We discuss if the Tevatron ttbar asymmetry can be explained by T-channel exchange of a W' gauge boson coupling to down and top quarks. In a spontaneously broken gauge theory, such a W' is necessarily accompanied by a Z' at a similar mass scale. Null results from Tevatron searches for dijet and dilepton resonances imply large mass splitting between the $W'$ and $Z'$. We argue that such splitting can only be accomplished if the gauge symmetry is broken by a scalar in a large dimension representation of the gauge group, for which no perturbative description exists.
1501.04103
Mao Zeng
S. Dawson, I. M. Lewis, Mao Zeng
Usefulness of effective field theory for boosted Higgs production
21 pages, 13 figures. Minor changes made in version 2
Phys. Rev. D 91, 074012 (2015)
10.1103/PhysRevD.91.074012
SLAC-PUB-16208
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Higgs + jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high p_T. We examine the production process using an effective field theory (EFT) language and discuss the possibility of determining the nature of the underlying high scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension-5 and dimension-7 are included in the EFT. As a by-product of our study, we examine the region of validity of the EFT. Dimension-7 contributions in realistic new physics models give effects in the high p_T tail of the Higgs signal which are so tiny that they are likely to be unobservable.
[ { "created": "Fri, 16 Jan 2015 21:00:04 GMT", "version": "v1" }, { "created": "Wed, 22 Apr 2015 17:14:02 GMT", "version": "v2" } ]
2015-04-24
[ [ "Dawson", "S.", "" ], [ "Lewis", "I. M.", "" ], [ "Zeng", "Mao", "" ] ]
The Higgs + jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high p_T. We examine the production process using an effective field theory (EFT) language and discuss the possibility of determining the nature of the underlying high scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension-5 and dimension-7 are included in the EFT. As a by-product of our study, we examine the region of validity of the EFT. Dimension-7 contributions in realistic new physics models give effects in the high p_T tail of the Higgs signal which are so tiny that they are likely to be unobservable.
0709.2438
Gino Isidori
Gino Isidori
KAON 2007: Conference Summary
16 pages, 10 figures, to appear in the proceedings of the International Conference Kaon'07, Laboratori Nazionali di Frascati, Italy, 21-25 May 2007
PoSKAON:064,2008
null
null
hep-ph
null
A concise overview of the interesting recent developments in kaon phyiscs discussed at KAON 2007 is presented.
[ { "created": "Sat, 15 Sep 2007 18:03:27 GMT", "version": "v1" } ]
2008-11-26
[ [ "Isidori", "Gino", "" ] ]
A concise overview of the interesting recent developments in kaon phyiscs discussed at KAON 2007 is presented.
1112.5158
Torsten Bringmann
Masaki Asano, Torsten Bringmann, Christoph Weniger
Indirect dark matter searches as a probe of degenerate particle spectra
6 pages, 4 figures; minor updates to match the published version
Physics Letters B 709 (2012), pp. 128-132
10.1016/j.physletb.2012.02.017
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the possibility that the cosmological dark matter consists of particles very close in mass to new colored particles below the TeV scale. While such a scenario is inherently difficult to directly confirm at colliders, we find that indirect dark matter searches may be a powerful alternative. In particular, we show that in this case dark matter annihilation to quark-quark-gluon final states can give rise to significant antiproton (but also gamma-ray) fluxes, and compare the resulting constraints to bounds from direct searches at LEP, the Tevatron and the LHC. For supersymmetric neutralinos degenerate with squarks, e.g., antiprotons can give rise to more stringent constraints for masses below around 45-80 GeV.
[ { "created": "Wed, 21 Dec 2011 20:59:24 GMT", "version": "v1" }, { "created": "Fri, 2 Mar 2012 09:21:23 GMT", "version": "v2" } ]
2012-03-05
[ [ "Asano", "Masaki", "" ], [ "Bringmann", "Torsten", "" ], [ "Weniger", "Christoph", "" ] ]
We consider the possibility that the cosmological dark matter consists of particles very close in mass to new colored particles below the TeV scale. While such a scenario is inherently difficult to directly confirm at colliders, we find that indirect dark matter searches may be a powerful alternative. In particular, we show that in this case dark matter annihilation to quark-quark-gluon final states can give rise to significant antiproton (but also gamma-ray) fluxes, and compare the resulting constraints to bounds from direct searches at LEP, the Tevatron and the LHC. For supersymmetric neutralinos degenerate with squarks, e.g., antiprotons can give rise to more stringent constraints for masses below around 45-80 GeV.
hep-ph/0008223
Maxim Pospelov
Alon E. Faraggi and Maxim Pospelov
Self-Interacting Dark Matter from the Hidden Heterotic-String Sector
16 pages. standard LaTex
Astropart.Phys.16:451-461,2002
10.1016/S0927-6505(01)00121-9
OUTP-00-37P, UMN-TH-1918-00, TPI-MINN-00/42
hep-ph astro-ph hep-th
null
It has been suggested recently that self-interacting dark matter fits better the observational characteristics of galaxy dynamics. We propose that the self-interacting dark matter is composed from the glueballs of the hidden sector non-Abelian gauge group, while the hidden matter states exist in vector-like representation and decouple from the light spectrum. It is shown that these glueballs are semi-stable with the life-time larger than the present age of the Universe, if their mass is 1 GeV or less. The constraint on their abundance today suggests that the energy was stored in the hidden sector soon after inflation. This imposes an upper limit on the reheating temperature. We further study the naturalness of this scenario in the context of the free-fermionic string models and point out a class of such models where the self-interacting dark matter from the hidden sector is indeed plausible.
[ { "created": "Mon, 21 Aug 2000 23:27:02 GMT", "version": "v1" } ]
2011-05-23
[ [ "Faraggi", "Alon E.", "" ], [ "Pospelov", "Maxim", "" ] ]
It has been suggested recently that self-interacting dark matter fits better the observational characteristics of galaxy dynamics. We propose that the self-interacting dark matter is composed from the glueballs of the hidden sector non-Abelian gauge group, while the hidden matter states exist in vector-like representation and decouple from the light spectrum. It is shown that these glueballs are semi-stable with the life-time larger than the present age of the Universe, if their mass is 1 GeV or less. The constraint on their abundance today suggests that the energy was stored in the hidden sector soon after inflation. This imposes an upper limit on the reheating temperature. We further study the naturalness of this scenario in the context of the free-fermionic string models and point out a class of such models where the self-interacting dark matter from the hidden sector is indeed plausible.
hep-ph/0212153
Alexey Kiselev
N.N. Achasov and A.V. Kiselev
The new analysis of the KLOE data on the phi->eta pi0 gamma decay
11 pages, 2 figures
Phys.Rev.D68:014006,2003
10.1103/PhysRevD.68.014006
null
hep-ph hep-ex nucl-th
null
In this paper we present the fit to the recent high-statistical KLOE data on the phi -> eta pi^0 gamma decay. This decay mainly goes through the a_0 gamma intermediate state. The obtained results differ from those of the previous fits: data prefer a high a_0 mass and a considerably large a_0 coupling to the K\bar K}.
[ { "created": "Wed, 11 Dec 2002 06:08:14 GMT", "version": "v1" } ]
2008-11-26
[ [ "Achasov", "N. N.", "" ], [ "Kiselev", "A. V.", "" ] ]
In this paper we present the fit to the recent high-statistical KLOE data on the phi -> eta pi^0 gamma decay. This decay mainly goes through the a_0 gamma intermediate state. The obtained results differ from those of the previous fits: data prefer a high a_0 mass and a considerably large a_0 coupling to the K\bar K}.
hep-ph/0308304
Magno Machado
M.A. Betemps, M.B. Gay Ducati, M.V.T. Machado, J. Raufeisen
Dilepton Transverse Momentum in the Color Dipole Approach
6 pages, 2 figures. Contribution to 11th International Workshop on Deep-Inelastic Scattering (DIS03), St. Petersburg, April 2003
null
null
LA-UR-03-5879
hep-ph
null
We investigate the Drell-Yan transverse momentum distribution in the framework of the color dipole approach. Special attention is paid to parton saturation effects at high energies. Predictions at LHC energies ($\sqrt{s}=14$ TeV) are given and extrapolated down to ISR energies ($\sqrt{s}=62$ GeV). Unitarity corrections are implemented through the multiple scattering Glauber-Mueller approach and are compared with predictions of the BGBK saturation model.
[ { "created": "Thu, 28 Aug 2003 20:52:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Betemps", "M. A.", "" ], [ "Ducati", "M. B. Gay", "" ], [ "Machado", "M. V. T.", "" ], [ "Raufeisen", "J.", "" ] ]
We investigate the Drell-Yan transverse momentum distribution in the framework of the color dipole approach. Special attention is paid to parton saturation effects at high energies. Predictions at LHC energies ($\sqrt{s}=14$ TeV) are given and extrapolated down to ISR energies ($\sqrt{s}=62$ GeV). Unitarity corrections are implemented through the multiple scattering Glauber-Mueller approach and are compared with predictions of the BGBK saturation model.
2211.14562
Ya-Juan Zheng
Junmou Chen, Kaoru Hagiwara, Junichi Kanzaki, Kentarou Mawatari and Ya-Juan Zheng
Helicity amplitudes in light-cone and Feynman-diagram gauges
20 pages, 14 figures; references added
null
null
KEK-TH-2471, IPMU22-0055
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently proposed Feynman-diagram (FD) gauge propagator for massless and massive gauge bosons is obtained from a light-cone (LC) gauge propagator, by choosing the gauge vector along the opposite direction of the gauge boson three-momentum. We implement a general LC gauge propagator for all the gauge bosons of the Standard Model (SM) in the HELicity Amplitude Subroutines (HELAS) codes, such that all the SM helicity amplitudes can be evaluated at the tree level in the LC gauge by using MadGraph. We confirm that our numerical codes produce physical helicity amplitudes which are consistent among all gauge choices. We then study interference patterns among Feynman amplitudes, for a few $2\to3$ scattering processes in QED and QCD, and the process $\gamma\gamma\to W^+W^-$ followed by the $W^\pm$ decays. We find that in a generic LC gauge, where all the gauge boson propagators share a common gauge vector, we cannot remove the off-shell current components which grow with their energy systematically from all the Feynman amplitudes in $2\to3$ processes. On the other hand, the $5\times5$ LC gauge propagator for the weak bosons removes components which grow with energy due to the longitudinal polarization mode of the external bi-fermion currents, and hence can give $2\to2$ weak boson scattering amplitudes which are free from subtle cancellation at high energies. The particular choice of the FD gauge vector has advantages over generic LC gauge, not only because all the terms which grow with energy of off-shell and on-shell currents are removed systematically from all the diagrams, but also because no artificial gauge vector direction dependence of individual amplitudes appears.
[ { "created": "Sat, 26 Nov 2022 13:25:03 GMT", "version": "v1" }, { "created": "Sun, 19 Nov 2023 07:30:06 GMT", "version": "v2" } ]
2023-11-21
[ [ "Chen", "Junmou", "" ], [ "Hagiwara", "Kaoru", "" ], [ "Kanzaki", "Junichi", "" ], [ "Mawatari", "Kentarou", "" ], [ "Zheng", "Ya-Juan", "" ] ]
Recently proposed Feynman-diagram (FD) gauge propagator for massless and massive gauge bosons is obtained from a light-cone (LC) gauge propagator, by choosing the gauge vector along the opposite direction of the gauge boson three-momentum. We implement a general LC gauge propagator for all the gauge bosons of the Standard Model (SM) in the HELicity Amplitude Subroutines (HELAS) codes, such that all the SM helicity amplitudes can be evaluated at the tree level in the LC gauge by using MadGraph. We confirm that our numerical codes produce physical helicity amplitudes which are consistent among all gauge choices. We then study interference patterns among Feynman amplitudes, for a few $2\to3$ scattering processes in QED and QCD, and the process $\gamma\gamma\to W^+W^-$ followed by the $W^\pm$ decays. We find that in a generic LC gauge, where all the gauge boson propagators share a common gauge vector, we cannot remove the off-shell current components which grow with their energy systematically from all the Feynman amplitudes in $2\to3$ processes. On the other hand, the $5\times5$ LC gauge propagator for the weak bosons removes components which grow with energy due to the longitudinal polarization mode of the external bi-fermion currents, and hence can give $2\to2$ weak boson scattering amplitudes which are free from subtle cancellation at high energies. The particular choice of the FD gauge vector has advantages over generic LC gauge, not only because all the terms which grow with energy of off-shell and on-shell currents are removed systematically from all the diagrams, but also because no artificial gauge vector direction dependence of individual amplitudes appears.
0902.2803
A. D. Polosa
NV Drenska, R Faccini, AD Polosa
Exotic Hadrons with Hidden Charm and Strangeness
6 pages, 2 figures, minor changes made, references added
Phys.Rev.D79:077502,2009
10.1103/PhysRevD.79.077502
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate on exotic tetraquark hadrons of the kind [cs][cbar sbar] by computing their spectrum and decay modes within a constituent diquark-antidiquark model. We also compare these predictions with the present experimental knowledge.
[ { "created": "Mon, 16 Feb 2009 22:52:15 GMT", "version": "v1" }, { "created": "Fri, 3 Apr 2009 08:59:24 GMT", "version": "v2" } ]
2013-05-29
[ [ "Drenska", "NV", "" ], [ "Faccini", "R", "" ], [ "Polosa", "AD", "" ] ]
We investigate on exotic tetraquark hadrons of the kind [cs][cbar sbar] by computing their spectrum and decay modes within a constituent diquark-antidiquark model. We also compare these predictions with the present experimental knowledge.
1007.0375
Johannes Bluemlein
J. Ablinger, I. Bierenbaum, J. Bl\"umlein, A. Hasselhuhhn, S. Klein, C. Schneider, and F. Wi{\ss}brock
Heavy Flavor DIS Wilson coefficients in the asymptotic regime
8 pages LATEX, 4 figures, 1 style file
Nucl.Phys.Proc.Suppl.205-206:242-249,2010
10.1016/j.nuclphysbps.2010.08.050
DESY 10-093, SFB/CPP-10-58, IFIC/10-22, TTK-10-38
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on results for the heavy flavor contributions to $F_2(x,Q^2)$ in the limit $Q^2\gg m^2$ at {\sf NNLO}. By calculating the massive $3$--loop operator matrix elements, we account for all but the power suppressed terms in $m^2/Q^2$. Recently, the calculation of fixed Mellin moments of all $3$--loop massive operator matrix elements has been finished. We present new all--$N$ results for the $O(n_f)$--terms, thereby confirming the corresponding parts of the $3$--loop anomalous dimensions. Additionally, we report on first genuine $3$--loop results of the ladder--type diagrams for general values of the Mellin variable $N$.
[ { "created": "Fri, 2 Jul 2010 14:43:49 GMT", "version": "v1" } ]
2016-08-14
[ [ "Ablinger", "J.", "" ], [ "Bierenbaum", "I.", "" ], [ "Blümlein", "J.", "" ], [ "Hasselhuhhn", "A.", "" ], [ "Klein", "S.", "" ], [ "Schneider", "C.", "" ], [ "Wißbrock", "F.", "" ] ]
We report on results for the heavy flavor contributions to $F_2(x,Q^2)$ in the limit $Q^2\gg m^2$ at {\sf NNLO}. By calculating the massive $3$--loop operator matrix elements, we account for all but the power suppressed terms in $m^2/Q^2$. Recently, the calculation of fixed Mellin moments of all $3$--loop massive operator matrix elements has been finished. We present new all--$N$ results for the $O(n_f)$--terms, thereby confirming the corresponding parts of the $3$--loop anomalous dimensions. Additionally, we report on first genuine $3$--loop results of the ladder--type diagrams for general values of the Mellin variable $N$.
0810.5730
Fotios Ptochos
P. Giromini, F. Happacher, M. J. Kim, M. Kruse, K. Pitts, F. Ptohos, and S. Torre
Phenomenological interpretation of the multi-muon events reported by the CDF collaboration
6 pages, 9 figures. Submitted to Phys. Rev. D. Rapid Communication
null
null
FERMILAB-PUB-08-231-E
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a phenomenological conjecture of new physics that is suggested by the topology and kinematic properties of the multi-muon events recently reported by the CDF collaboration. We show that the salient features of the data can be accounted for by postulating the pair production of three new states h1, h2, and h3 with masses in the range of 15, 7.3 and 3.6 GeV/c^2, respectively. The heavier states cascade-decay into the lighter ones, whereas the lightest state decays into a tau pair with a lifetime of the order of 20 ps.
[ { "created": "Fri, 31 Oct 2008 16:30:33 GMT", "version": "v1" } ]
2008-11-03
[ [ "Giromini", "P.", "" ], [ "Happacher", "F.", "" ], [ "Kim", "M. J.", "" ], [ "Kruse", "M.", "" ], [ "Pitts", "K.", "" ], [ "Ptohos", "F.", "" ], [ "Torre", "S.", "" ] ]
We present a phenomenological conjecture of new physics that is suggested by the topology and kinematic properties of the multi-muon events recently reported by the CDF collaboration. We show that the salient features of the data can be accounted for by postulating the pair production of three new states h1, h2, and h3 with masses in the range of 15, 7.3 and 3.6 GeV/c^2, respectively. The heavier states cascade-decay into the lighter ones, whereas the lightest state decays into a tau pair with a lifetime of the order of 20 ps.
1304.6856
Tanushree Basak
Tanushree Basak, Subhendra Mohanty
130 GeV gamma ray line and enhanced Higgs di-photon rate from Triplet-Singlet extended MSSM
ref. updated, version accepted for publication in JHEP
JHEP08(2013)020
10.1007/JHEP08(2013)020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an economic extension of minimal supersymmetric standard model with a SU(2) singlet and Y=0 triplet, which can explain (i) the 125 GeV Higgs boson without fine tuning, (ii) the 130 GeV $\gamma$-ray line seen at Fermi-LAT, (as well as a second photon line at 114 GeV)(iii) an enhanced Higgs di-photon decay rate seen by ATLAS, while being consistent with dark matter relic density and recent XENON 100 exclusion limits on spin-independent direct detection cross-section. We obtain the required cross-section of $10^{-27}cm^3s^{-1}$ for the 130 GeV $\gamma$-ray flux through the resonant annihilation of dark matter via pseudoscalar triplet Higgs of mass $\sim$260 GeV. The dark matter is predominantly bino-higgsino which has large couplings with photons (through higgsino) and gives correct relic density (through bino). We get the enhanced Higgs diphoton decay rate, $R_{\gamma \gamma}\simeq 1.24$ dominantly contributed by the light chargino-loops, which can account for the reported excess seen in the $h\rightarrow \gamma \gamma$ channel by ATLAS.
[ { "created": "Thu, 25 Apr 2013 10:04:06 GMT", "version": "v1" }, { "created": "Sun, 7 Jul 2013 16:08:15 GMT", "version": "v2" } ]
2015-06-15
[ [ "Basak", "Tanushree", "" ], [ "Mohanty", "Subhendra", "" ] ]
We propose an economic extension of minimal supersymmetric standard model with a SU(2) singlet and Y=0 triplet, which can explain (i) the 125 GeV Higgs boson without fine tuning, (ii) the 130 GeV $\gamma$-ray line seen at Fermi-LAT, (as well as a second photon line at 114 GeV)(iii) an enhanced Higgs di-photon decay rate seen by ATLAS, while being consistent with dark matter relic density and recent XENON 100 exclusion limits on spin-independent direct detection cross-section. We obtain the required cross-section of $10^{-27}cm^3s^{-1}$ for the 130 GeV $\gamma$-ray flux through the resonant annihilation of dark matter via pseudoscalar triplet Higgs of mass $\sim$260 GeV. The dark matter is predominantly bino-higgsino which has large couplings with photons (through higgsino) and gives correct relic density (through bino). We get the enhanced Higgs diphoton decay rate, $R_{\gamma \gamma}\simeq 1.24$ dominantly contributed by the light chargino-loops, which can account for the reported excess seen in the $h\rightarrow \gamma \gamma$ channel by ATLAS.
hep-ph/9308356
Qiping Xu
Q. P. Xu and A. N. Kamal
Chiral symmetry and many-body nonleptonic decays of bottom hadrons
6 pages, latex, figures included. Talk presented at the 5th International Symposium on Heavy Flavour Physics, Montreal, Canada, July 6-10, 1993
null
null
Alberta Thy-39-93
hep-ph
null
Chiral symmetry can be applied to many-body nonleptonic decays of heavy hadrons. We establish the chiral effective Hamiltonian for some typical many-body nonleptonic decays of bottom hadrons. We discuss the lowest-order contributions coming from such a Hamiltonian and present, as an example, a calculation of decay distributions of $B^-\to D^+ D^-_s \pi^-$ and $B^-\to D^{\ast +} D^-_s \pi^-$. We emphasize that wide applications of this method are possible.
[ { "created": "Sat, 28 Aug 1993 19:44:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Xu", "Q. P.", "" ], [ "Kamal", "A. N.", "" ] ]
Chiral symmetry can be applied to many-body nonleptonic decays of heavy hadrons. We establish the chiral effective Hamiltonian for some typical many-body nonleptonic decays of bottom hadrons. We discuss the lowest-order contributions coming from such a Hamiltonian and present, as an example, a calculation of decay distributions of $B^-\to D^+ D^-_s \pi^-$ and $B^-\to D^{\ast +} D^-_s \pi^-$. We emphasize that wide applications of this method are possible.
2005.07737
Celso de Camargo Barros Jr.
Marcelo G. L. Nogueira-Santos, Celso C. Barros Jr
Low energy pion-$\Lambda_b$ interaction
8 pages, 7 figures
null
10.1140/epjc/s10052-020-8151-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the low energy pion-$\Lambda_b$ interaction considering effecective chiral Lagrangians that include pions, baryons and the corresponding resonances. Interactions mediated by a $\sigma$ meson exchange are also considered. The scattering amplitudes are calculated and then we determine the angular distributions and polarizations.
[ { "created": "Fri, 15 May 2020 18:44:28 GMT", "version": "v1" } ]
2020-07-15
[ [ "Nogueira-Santos", "Marcelo G. L.", "" ], [ "Barros", "Celso C.", "Jr" ] ]
In this work we study the low energy pion-$\Lambda_b$ interaction considering effecective chiral Lagrangians that include pions, baryons and the corresponding resonances. Interactions mediated by a $\sigma$ meson exchange are also considered. The scattering amplitudes are calculated and then we determine the angular distributions and polarizations.
hep-ph/0610351
Ivo de Medeiros Varzielas
I. de Medeiros Varzielas
Neutrino tri-bi-maximal mixing from Delta(27)
to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 2006
AIPConf.Proc.903:397-400,2007
10.1063/1.2735208
null
hep-ph
null
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal, putting leptonic mixing in contrast with the small mixing of the quark sector. We discuss a model in which Delta(27) (a subgroup of SU(3)) is the family symmetry, and tri-bi-maximal mixing directly follows from the vacuum structure enforced by the discrete symmetry. The model accounts for the observed quark and lepton masses and the CKM matrix, as well as being consistent with an underlying stage of Grand Unification.
[ { "created": "Thu, 26 Oct 2006 09:23:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Varzielas", "I. de Medeiros", "" ] ]
The observed neutrino mixing, having a near maximal atmospheric neutrino mixing angle and a large solar mixing angle, is close to tri-bi-maximal, putting leptonic mixing in contrast with the small mixing of the quark sector. We discuss a model in which Delta(27) (a subgroup of SU(3)) is the family symmetry, and tri-bi-maximal mixing directly follows from the vacuum structure enforced by the discrete symmetry. The model accounts for the observed quark and lepton masses and the CKM matrix, as well as being consistent with an underlying stage of Grand Unification.
1106.5927
Zhen-hua Zhao
Chun Liu, Jin-tao Tian, Zhen-hua Zhao
MINOS Anomaly as A Signal of Lorentz Violation
9 pages, 4 figures, references added, accepted for publication in PLB
Phys.Lett.B702:154-157,2011
10.1016/j.physletb.2011.06.084
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the MINOS collaboration reported an anomaly that the mass-squared difference and mixing angle of $\bar{\nu}_\mu$ $\leftrightarrow$ $\bar{\nu}_\tau$ are both different from that of $\nu_\mu$ $\leftrightarrow$ $\nu_\tau$. In this paper, based on the framework of neutrino oscillations, terms that break the Lorentz symmetry are used as perturbation to explain this anomaly and satisfactory results are got. Remarkably, some surprising conclusions, one of which is that in the high energy limit (hundreds of GeV) neutrino oscillation pattern will be independent of energy, are also arrived.
[ { "created": "Wed, 29 Jun 2011 12:56:16 GMT", "version": "v1" }, { "created": "Tue, 5 Jul 2011 14:56:29 GMT", "version": "v2" } ]
2011-07-25
[ [ "Liu", "Chun", "" ], [ "Tian", "Jin-tao", "" ], [ "Zhao", "Zhen-hua", "" ] ]
Recently, the MINOS collaboration reported an anomaly that the mass-squared difference and mixing angle of $\bar{\nu}_\mu$ $\leftrightarrow$ $\bar{\nu}_\tau$ are both different from that of $\nu_\mu$ $\leftrightarrow$ $\nu_\tau$. In this paper, based on the framework of neutrino oscillations, terms that break the Lorentz symmetry are used as perturbation to explain this anomaly and satisfactory results are got. Remarkably, some surprising conclusions, one of which is that in the high energy limit (hundreds of GeV) neutrino oscillation pattern will be independent of energy, are also arrived.
hep-ph/9307252
null
R. Alemany, J.J. Gomez-Cadenas, M.C. Gonzalez-Garcia and J.W.F. Valle
Searching for Exotic Tau Decays
CERN-PPE/93-49, MAD/PH/741, FTUV/92-588. 29 Pages in REVTeX. 13 Figures available upon request
null
null
null
hep-ph
null
We discuss the potential of $\tau$-charm and B factories for the search of new physics through the study of rare $\tau$ decays. We consider decays that involve the violation of lepton flavour conservation. Such decays bear a close relationship to the physics of neutrino mass and the properties of the lepton sector of the electroweak theory.
[ { "created": "Mon, 12 Jul 1993 15:55:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Alemany", "R.", "" ], [ "Gomez-Cadenas", "J. J.", "" ], [ "Gonzalez-Garcia", "M. C.", "" ], [ "Valle", "J. W. F.", "" ] ]
We discuss the potential of $\tau$-charm and B factories for the search of new physics through the study of rare $\tau$ decays. We consider decays that involve the violation of lepton flavour conservation. Such decays bear a close relationship to the physics of neutrino mass and the properties of the lepton sector of the electroweak theory.
1202.5592
Lei Guo
Li Xiao-Peng, Guo Lei, Ma Wen-Gan, Han Liang, Zhang Ren-You, and Wang Shao-Ming
Single slepton production associated with a top quark at LHC in NLO QCD
33 pages, 18 figures, published version of EPJC
Eur. Phys. J. C (2012) 72:1918
10.1140/epjc/s10052-012-1918-0
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Single slepton production in association with a top quark at the CERN Large Hadron Collider (LHC) is one of the important processes in probing the R-parity violation couplings. We calculate the QCD next-to-leading order (NLO) corrections to the $pp \to t\slep^{-}(\bar{t}\slep^{+})+X$ process at the LHC and discuss the impacts of the QCD corrections on kinematic distributions. We investigate the dependence of the leading order (LO) and the NLO QCD corrected integrated cross section on the factorization/renormalization energy scale, slepton, stop-quark and gluino masses. We find that the uncertainty of the LO cross section due to the energy scale is obviously improved by the NLO QCD corrections, and the exclusive jet event selection scheme keeps the convergence of the perturbative series better than the inclusive scheme. The results show that the polarization asymmetry of the top-quark will be reduced by the NLO QCD corrections, and the QCD corrections generally increase with the increment of the $\tilde{t}_1$ or $\tilde{g}$ mass value.
[ { "created": "Sat, 25 Feb 2012 00:44:12 GMT", "version": "v1" }, { "created": "Fri, 9 Mar 2012 06:40:23 GMT", "version": "v2" } ]
2012-03-29
[ [ "Xiao-Peng", "Li", "" ], [ "Lei", "Guo", "" ], [ "Wen-Gan", "Ma", "" ], [ "Liang", "Han", "" ], [ "Ren-You", "Zhang", "" ], [ "Shao-Ming", "Wang", "" ] ]
Single slepton production in association with a top quark at the CERN Large Hadron Collider (LHC) is one of the important processes in probing the R-parity violation couplings. We calculate the QCD next-to-leading order (NLO) corrections to the $pp \to t\slep^{-}(\bar{t}\slep^{+})+X$ process at the LHC and discuss the impacts of the QCD corrections on kinematic distributions. We investigate the dependence of the leading order (LO) and the NLO QCD corrected integrated cross section on the factorization/renormalization energy scale, slepton, stop-quark and gluino masses. We find that the uncertainty of the LO cross section due to the energy scale is obviously improved by the NLO QCD corrections, and the exclusive jet event selection scheme keeps the convergence of the perturbative series better than the inclusive scheme. The results show that the polarization asymmetry of the top-quark will be reduced by the NLO QCD corrections, and the QCD corrections generally increase with the increment of the $\tilde{t}_1$ or $\tilde{g}$ mass value.
1102.2340
Encieh Erfani
Manuel Drees and Encieh Erfani
Running-Mass Inflation Model and Primordial Black Holes
22 pages, 6 figures, Refs. added, Published in JCAP
JCAP 1104:005,2011
10.1088/1475-7516/2011/04/005
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the question whether the running-mass inflation model allows the formation of Primordial Black Holes (PBHs) that are sufficiently long-lived to serve as candidates for Dark Matter. We incorporate recent cosmological data, including the WMAP 7-year results. Moreover, we include "the running of the running" of the spectral index of the power spectrum, as well as the renormalization group "running of the running" of the inflaton mass term. Our analysis indicates that formation of sufficiently heavy, and hence long-lived, PBHs still remains possible in this scenario. As a by-product, we show that the additional term in the inflaton potential still does not allow significant negative running of the spectral index.
[ { "created": "Fri, 11 Feb 2011 12:57:44 GMT", "version": "v1" }, { "created": "Mon, 4 Apr 2011 08:12:43 GMT", "version": "v2" }, { "created": "Fri, 8 Apr 2011 08:04:25 GMT", "version": "v3" } ]
2015-03-18
[ [ "Drees", "Manuel", "" ], [ "Erfani", "Encieh", "" ] ]
We revisit the question whether the running-mass inflation model allows the formation of Primordial Black Holes (PBHs) that are sufficiently long-lived to serve as candidates for Dark Matter. We incorporate recent cosmological data, including the WMAP 7-year results. Moreover, we include "the running of the running" of the spectral index of the power spectrum, as well as the renormalization group "running of the running" of the inflaton mass term. Our analysis indicates that formation of sufficiently heavy, and hence long-lived, PBHs still remains possible in this scenario. As a by-product, we show that the additional term in the inflaton potential still does not allow significant negative running of the spectral index.
hep-ph/9801348
Gomez Mario
M.E. Gomez and K. Tamvakis
A Note On R-Parity Violation and Fermion Masses
8 pages, uses LaTeX2e
Phys. Rev. D 58, 057701 (1998)
10.1103/PhysRevD.58.057701
null
hep-ph
null
We consider a class of supersymmetric SU(3)\times SU(2)\times U(1) multihiggs models in which R-parity is violated through bilinear Higgs-lepton interactions. The required, due to R-parity violation, higgs-lepton rotations introduce an alternative way to generate the phenomenologically desirable fermion mass matrix structures independently of the equality of Yukawas, possibly imposed by superstring or other unification.
[ { "created": "Mon, 19 Jan 1998 18:08:32 GMT", "version": "v1" } ]
2016-08-25
[ [ "Gomez", "M. E.", "" ], [ "Tamvakis", "K.", "" ] ]
We consider a class of supersymmetric SU(3)\times SU(2)\times U(1) multihiggs models in which R-parity is violated through bilinear Higgs-lepton interactions. The required, due to R-parity violation, higgs-lepton rotations introduce an alternative way to generate the phenomenologically desirable fermion mass matrix structures independently of the equality of Yukawas, possibly imposed by superstring or other unification.
hep-ph/0504258
Torleif E. O. Ericson
T. E. O. Ericson (CERN)
Isospin Violation in Pion-Nucleon Scattering at Threshold
10 pages, 1 eps figure. Invited talk to appear in Proceedings of EXA05, Vienna, Feb. 21-25 2005, Verlag der oesterreichischen Akademie des Wissenschaften
null
null
CERN-PH-TH/2005-075
hep-ph
null
We discuss the electromagnetic corrections to the pion-nucleon scattering lengths generated by minimal e. m. coupling from a knowledge of the low energy expansion of the pion-nucleon elastic scattering amplitude as well as from the nucleon and delta pole terms, all a consequence of purely strong interactions. We assume the heavy baryon limit; the e.m. and axial form factors and the masses are used with their empirical values, such that there is no free parameter. The different terms have a clear physical and intuitive origin. In particular, a large isospin breaking contribution to the isoscalar term appears for the elastic charged-pion scattering lengths. We attempt a comparison to the results from chiral effective field theory (EFT) with a physical interpretation of the empirical constants in that approach. The results are applied to the energy shift and width of pionic hydrogen.
[ { "created": "Wed, 27 Apr 2005 13:44:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ericson", "T. E. O.", "", "CERN" ] ]
We discuss the electromagnetic corrections to the pion-nucleon scattering lengths generated by minimal e. m. coupling from a knowledge of the low energy expansion of the pion-nucleon elastic scattering amplitude as well as from the nucleon and delta pole terms, all a consequence of purely strong interactions. We assume the heavy baryon limit; the e.m. and axial form factors and the masses are used with their empirical values, such that there is no free parameter. The different terms have a clear physical and intuitive origin. In particular, a large isospin breaking contribution to the isoscalar term appears for the elastic charged-pion scattering lengths. We attempt a comparison to the results from chiral effective field theory (EFT) with a physical interpretation of the empirical constants in that approach. The results are applied to the energy shift and width of pionic hydrogen.
hep-ph/0004160
Gabriela Barenboim
G. Barenboim and F. Scheck (Mainz)
Tau neutrinos from muon storage rings
11 pages, 5 postscript figures (eps)
Phys.Lett.B485:171-177,2000
10.1016/S0370-2693(00)00708-5
null
hep-ph
null
Charged tau leptons emerging in a long baseline experiment with a muon storage ring and a far-away detector will positively establish neutrino oscillations. We study the conversion of $\nu_\mu$ ($\bar{\nu}_\mu$) and of $\bar{\nu}_e$ ($\nu_e$) to $\nu_\tau$ or $\bar{\nu}_\tau$ for neutrinos from a 20 GeV muon storage ring, within the strong mixing scheme and on the basis of the squared mass differences which are compatible with all reported neutrino anomalies, including the LSND data. In contrast to other solutions which ignore the Los Alamos anomaly, we find charged tau production rates which should be measurable in a realistic set up. As a consequence, determining the complete mass spectrum of neutrinos as well as all three mixing angles seems within reach. Matter effects are discussed thoroughly but are found to be small in this situation.
[ { "created": "Mon, 17 Apr 2000 11:00:00 GMT", "version": "v1" } ]
2014-11-17
[ [ "Barenboim", "G.", "", "Mainz" ], [ "Scheck", "F.", "", "Mainz" ] ]
Charged tau leptons emerging in a long baseline experiment with a muon storage ring and a far-away detector will positively establish neutrino oscillations. We study the conversion of $\nu_\mu$ ($\bar{\nu}_\mu$) and of $\bar{\nu}_e$ ($\nu_e$) to $\nu_\tau$ or $\bar{\nu}_\tau$ for neutrinos from a 20 GeV muon storage ring, within the strong mixing scheme and on the basis of the squared mass differences which are compatible with all reported neutrino anomalies, including the LSND data. In contrast to other solutions which ignore the Los Alamos anomaly, we find charged tau production rates which should be measurable in a realistic set up. As a consequence, determining the complete mass spectrum of neutrinos as well as all three mixing angles seems within reach. Matter effects are discussed thoroughly but are found to be small in this situation.
0911.0734
Yu-Kuo Hsiao
Kingman Cheung, Cheng-Wei Chiang, Yu-Kuo Hsiao, and Tzu-Chiang Yuan
Longitudinal Weak Gauge Bosons Scattering in Hidden Z' Models
18 pages, 4 figures, and 2 tables, version to appear in PRD
Phys.Rev.D81:053001,2010
10.1103/PhysRevD.81.053001
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Longitudinal weak gauge boson scattering has been well known as a powerful method to probe the underlying mechanism of the electroweak symmetry breaking sector of the Standard Model. We point out that longitudinal weak gauge boson scattering is also sensitive to the gauge sector when the non-Abelian trilinear and quartic couplings of the Standard Model Z boson are modified due to the general mixings with another Z' boson in the hidden sector and possibly with the photon as well. In particular, these mixings can lead to a partially strong scattering effect in the channels of W^\pm_L W^\pm_L \to W^\pm_L W^\pm_L and W^\pm_L W^\mp_L \to W^\pm_L W^\mp_L which can be probed at the Large Hadron Collider. We study this effect in a simple U(1) extension of the Standard Model recently suggested in the literature that includes both the symmetry breaking Higgs mechanism as well as the gauge invariant Stueckelberg mass terms for the two Abelian groups. Other types of Z' models are also briefly discussed.
[ { "created": "Wed, 4 Nov 2009 05:49:42 GMT", "version": "v1" }, { "created": "Wed, 18 Nov 2009 06:51:28 GMT", "version": "v2" }, { "created": "Tue, 2 Mar 2010 09:07:37 GMT", "version": "v3" } ]
2010-04-06
[ [ "Cheung", "Kingman", "" ], [ "Chiang", "Cheng-Wei", "" ], [ "Hsiao", "Yu-Kuo", "" ], [ "Yuan", "Tzu-Chiang", "" ] ]
Longitudinal weak gauge boson scattering has been well known as a powerful method to probe the underlying mechanism of the electroweak symmetry breaking sector of the Standard Model. We point out that longitudinal weak gauge boson scattering is also sensitive to the gauge sector when the non-Abelian trilinear and quartic couplings of the Standard Model Z boson are modified due to the general mixings with another Z' boson in the hidden sector and possibly with the photon as well. In particular, these mixings can lead to a partially strong scattering effect in the channels of W^\pm_L W^\pm_L \to W^\pm_L W^\pm_L and W^\pm_L W^\mp_L \to W^\pm_L W^\mp_L which can be probed at the Large Hadron Collider. We study this effect in a simple U(1) extension of the Standard Model recently suggested in the literature that includes both the symmetry breaking Higgs mechanism as well as the gauge invariant Stueckelberg mass terms for the two Abelian groups. Other types of Z' models are also briefly discussed.
2009.05779
Andrew Akeroyd
A.G. Akeroyd, Stefano Moretti, Tetsuo Shindou, Muyuan Song
CP asymmetries of ${\overline B}\to X_s/X_d\gamma$ in models with three Higgs doublets
25 pages, 14 figures
Phys. Rev. D 103, 015035 (2021)
10.1103/PhysRevD.103.015035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Direct CP asymmetries (${\cal A}_{CP}$) in the inclusive decays of ${\overline B}\to X_s\gamma$ and ${\overline B}\to X_{s+d}\gamma$ of the order of $1\%$ will be probed at the BELLE II experiment. In this work, three such asymmetries are studied in the context of a three-Higgs-doublet model (3HDM), and it is shown that all three ${\cal A}_{CP}$ can be as large as the current experimental limits. Of particular interest is ${\cal A}_{CP}$ for ${\overline B}\to X_{s+d}\gamma$, which is predicted to be effectively zero in the Standard Model (SM). A measurement of $2.5\%$ or more for this observable with the full BELLE II data would give $5\sigma$ evidence for physics beyond the SM. We display parameter space in the 3HDM for which such a clear signal is possible.
[ { "created": "Sat, 12 Sep 2020 12:34:14 GMT", "version": "v1" } ]
2021-02-03
[ [ "Akeroyd", "A. G.", "" ], [ "Moretti", "Stefano", "" ], [ "Shindou", "Tetsuo", "" ], [ "Song", "Muyuan", "" ] ]
Direct CP asymmetries (${\cal A}_{CP}$) in the inclusive decays of ${\overline B}\to X_s\gamma$ and ${\overline B}\to X_{s+d}\gamma$ of the order of $1\%$ will be probed at the BELLE II experiment. In this work, three such asymmetries are studied in the context of a three-Higgs-doublet model (3HDM), and it is shown that all three ${\cal A}_{CP}$ can be as large as the current experimental limits. Of particular interest is ${\cal A}_{CP}$ for ${\overline B}\to X_{s+d}\gamma$, which is predicted to be effectively zero in the Standard Model (SM). A measurement of $2.5\%$ or more for this observable with the full BELLE II data would give $5\sigma$ evidence for physics beyond the SM. We display parameter space in the 3HDM for which such a clear signal is possible.
1404.7510
Howard Baer
Howard Baer, Vernon Barger, Dan Mickelson, Azar Mustafayev and Xerxes Tata
Physics at a Higgsino Factory
28 pages
null
10.1007/JHEP06(2014)172
UH-511-1234-14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Naturalness arguments applied to supersymmetric theories imply a spectrum containing four light higgsinos \tz_{1,2} and \tw_1^+- with masses ~ 100-300 GeV (the closer to M_Z the more natural). The compressed mass spectrum and associated low energy release from \tw_1 and \tz_2 three-body decay makes higgsinos difficult to detect at LHC14, while the other sparticles might be heavy, and possibly even beyond LHC14 reach. In contrast, the International Linear e^+e^- Collider (ILC) with \sqrt{s}>2m(higgsino) would be a {\it higgsino factory} in addition to a Higgs boson factory and would serve as a discovery machine for natural SUSY! In this case, both chargino and neutralino production %which give rise to distinct event topologies, occur at comparable rates, and lead to observable signals above SM backgrounds. We examine two benchmark cases, one just beyond the LHC8 reach with \tw_1(\tz_2)-\tz_1 mass gap of 15 (21) GeV, and a second more difficult case beyond even the LHC14 reach, where the mass gap is just 10 GeV, close to its minimum in models with no worse than 3% fine-tuning. The signal is characterized by low visible energy events together with MET in the one or two jets +1\ell channel from chargino production, and in the opposite sign, same-flavour, acoplanar dilepton channel from \tz_1\tz_2 production. For both cases, we find that the signal is observable above backgrounds from the usual 2-> 2 SM events and from \gamma\gamma collisions with just a few fb^{-1} of integrated luminosity. We also show that with an integrated luminosity of 100~fb^{-1}, it should be possible to extract \tw_1, \tz_2 and \tz_1 masses to percent level. These measurements would point to higgsinos as the origin of new physics and strongly suggest a link to a natural origin for W, Z and h masses.
[ { "created": "Tue, 29 Apr 2014 20:02:15 GMT", "version": "v1" } ]
2015-06-19
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Mickelson", "Dan", "" ], [ "Mustafayev", "Azar", "" ], [ "Tata", "Xerxes", "" ] ]
Naturalness arguments applied to supersymmetric theories imply a spectrum containing four light higgsinos \tz_{1,2} and \tw_1^+- with masses ~ 100-300 GeV (the closer to M_Z the more natural). The compressed mass spectrum and associated low energy release from \tw_1 and \tz_2 three-body decay makes higgsinos difficult to detect at LHC14, while the other sparticles might be heavy, and possibly even beyond LHC14 reach. In contrast, the International Linear e^+e^- Collider (ILC) with \sqrt{s}>2m(higgsino) would be a {\it higgsino factory} in addition to a Higgs boson factory and would serve as a discovery machine for natural SUSY! In this case, both chargino and neutralino production %which give rise to distinct event topologies, occur at comparable rates, and lead to observable signals above SM backgrounds. We examine two benchmark cases, one just beyond the LHC8 reach with \tw_1(\tz_2)-\tz_1 mass gap of 15 (21) GeV, and a second more difficult case beyond even the LHC14 reach, where the mass gap is just 10 GeV, close to its minimum in models with no worse than 3% fine-tuning. The signal is characterized by low visible energy events together with MET in the one or two jets +1\ell channel from chargino production, and in the opposite sign, same-flavour, acoplanar dilepton channel from \tz_1\tz_2 production. For both cases, we find that the signal is observable above backgrounds from the usual 2-> 2 SM events and from \gamma\gamma collisions with just a few fb^{-1} of integrated luminosity. We also show that with an integrated luminosity of 100~fb^{-1}, it should be possible to extract \tw_1, \tz_2 and \tz_1 masses to percent level. These measurements would point to higgsinos as the origin of new physics and strongly suggest a link to a natural origin for W, Z and h masses.
hep-ph/9805414
David Miller
D. J. Miller (RAL) and Michael H. Seymour (RAL)
Secondary Heavy Quark Pair Production in e+e- Annihilation
11 pages, 4 postscript figures
Phys.Lett.B435:213-220,1998
10.1016/S0370-2693(98)00773-4
RAL-TR-98-042
hep-ph
null
The multiplicity of heavy quarks from gluon splitting in e+e- annihilation has now been theoretically calculated and experimentally measured at LEP. However, the experimental measurement requires theoretical input for the shape of the multiplicity with respect to an event shape. In this paper we calculate the multiplicity of heavy quarks from gluon splitting in e+e- annihilation as a function of the heavy jet mass of the event, to next-to-leading logarithmic accuracy. We compare our result with Monte Carlo predictions.
[ { "created": "Thu, 21 May 1998 16:41:59 GMT", "version": "v1" } ]
2009-04-13
[ [ "Miller", "D. J.", "", "RAL" ], [ "Seymour", "Michael H.", "", "RAL" ] ]
The multiplicity of heavy quarks from gluon splitting in e+e- annihilation has now been theoretically calculated and experimentally measured at LEP. However, the experimental measurement requires theoretical input for the shape of the multiplicity with respect to an event shape. In this paper we calculate the multiplicity of heavy quarks from gluon splitting in e+e- annihilation as a function of the heavy jet mass of the event, to next-to-leading logarithmic accuracy. We compare our result with Monte Carlo predictions.
2009.13547
Subhasis Samanta
Subhasis Samanta and Francesco Giacosa
QFT treatment of a bound state in a thermal gas
Accepted for publication in Physical Review D
Phys. Rev. D 102, 116023 (2020)
10.1103/PhysRevD.102.116023
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate how to include bound states in a thermal gas in the context of quantum field theory (QFT). To this end, we use for definiteness a scalar QFT with a $\varphi^{4}$ interaction, where the field $\varphi$ represents a particle with mass $m$. A bound state of the $\varphi$-$\varphi$ type is created when the coupling constant is negative and its modulus is larger than a certain critical value. We investigate the contribution of this bound state to the pressure of the thermal gas of the system by using the $S$-matrix formalism involving the derivative of the phase-shift scattering. Our analysis, which is based on an unitarized one-loop resumed approach which renders the theory finite and well-defined for each value of the coupling constant, leads to following main results: (i) We generalize the phase-shift formula in order to take into account within a unique formal approach the two-particle interaction as well as the bound state (if existent). (ii) \textit{On the one hand}, the number density of the bound state in the system at a certain temperature $T$ is obtained by the standard thermal integral; this is the case for any binding energy, even if it is much smaller than the temperature of the thermal gas. (iii) \textit{On the other hand}, the contribution of the bound state to the total pressure is partly -- but not completely -- canceled by the two-particle interaction contribution to the pressure. (iv) The pressure as function of the coupling constant is \textit{continuous} also at the critical coupling for the bound state formation: the jump in pressure due to the sudden appearance of the bound state is exactly canceled by an analogous jump (but with opposite sign) of the interaction contribution to the pressure.
[ { "created": "Mon, 28 Sep 2020 18:00:23 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 2020 13:49:39 GMT", "version": "v2" } ]
2021-01-01
[ [ "Samanta", "Subhasis", "" ], [ "Giacosa", "Francesco", "" ] ]
We investigate how to include bound states in a thermal gas in the context of quantum field theory (QFT). To this end, we use for definiteness a scalar QFT with a $\varphi^{4}$ interaction, where the field $\varphi$ represents a particle with mass $m$. A bound state of the $\varphi$-$\varphi$ type is created when the coupling constant is negative and its modulus is larger than a certain critical value. We investigate the contribution of this bound state to the pressure of the thermal gas of the system by using the $S$-matrix formalism involving the derivative of the phase-shift scattering. Our analysis, which is based on an unitarized one-loop resumed approach which renders the theory finite and well-defined for each value of the coupling constant, leads to following main results: (i) We generalize the phase-shift formula in order to take into account within a unique formal approach the two-particle interaction as well as the bound state (if existent). (ii) \textit{On the one hand}, the number density of the bound state in the system at a certain temperature $T$ is obtained by the standard thermal integral; this is the case for any binding energy, even if it is much smaller than the temperature of the thermal gas. (iii) \textit{On the other hand}, the contribution of the bound state to the total pressure is partly -- but not completely -- canceled by the two-particle interaction contribution to the pressure. (iv) The pressure as function of the coupling constant is \textit{continuous} also at the critical coupling for the bound state formation: the jump in pressure due to the sudden appearance of the bound state is exactly canceled by an analogous jump (but with opposite sign) of the interaction contribution to the pressure.
hep-ph/9209263
Jim Amundson
James F. Amundson and Jonathan L. Rosner
Heavy Quark Symmetry Violation in Semileptonic Decays of D Mesons
25 pages (LaTeX) + 7 pages of Postscript figures (included at end), EFI-92-36
Phys.Rev. D47 (1993) 1951-1963
10.1103/PhysRevD.47.1951
null
hep-ph
null
The decays of $D$ mesons to $K l \nu$ and $K^* l \nu$ final states exhibit significant deviations from the predictions of heavy-quark symmetry, as one might expect since the strange quark's mass is of the same order as the QCD scale. Nonetheless, in order to understand where the most significant effects might lie for heavier systems (such as $B \to D l\nu$ and $B \to D^* l\nu$), the pattern of these deviations is analyzed from the standpoint of perturbative QCD and ${\cal O}(1/m_s)$ corrections. Two main effects are noted. First, the perturbative QCD corrections lead to an overall decrease of predicted rates, which can be understood in terms of production of excited kaonic states. Second, ${\cal O}(1/m_s)$ effects tend to cancel the perturbative QCD corrections in the case of $Kl\nu$ decay, while they have minimal effect in $K^*l\nu$ decay.
[ { "created": "Tue, 22 Sep 1992 03:28:23 GMT", "version": "v1" } ]
2009-10-22
[ [ "Amundson", "James F.", "" ], [ "Rosner", "Jonathan L.", "" ] ]
The decays of $D$ mesons to $K l \nu$ and $K^* l \nu$ final states exhibit significant deviations from the predictions of heavy-quark symmetry, as one might expect since the strange quark's mass is of the same order as the QCD scale. Nonetheless, in order to understand where the most significant effects might lie for heavier systems (such as $B \to D l\nu$ and $B \to D^* l\nu$), the pattern of these deviations is analyzed from the standpoint of perturbative QCD and ${\cal O}(1/m_s)$ corrections. Two main effects are noted. First, the perturbative QCD corrections lead to an overall decrease of predicted rates, which can be understood in terms of production of excited kaonic states. Second, ${\cal O}(1/m_s)$ effects tend to cancel the perturbative QCD corrections in the case of $Kl\nu$ decay, while they have minimal effect in $K^*l\nu$ decay.
1109.6293
Bowen Xiao
Fabio Dominguez, Jian-Wei Qiu, Bo-Wen Xiao, Feng Yuan
On the linearly polarized gluon distributions in the color dipole model
10 pages,v2 with minor revision
null
10.1103/PhysRevD.85.045003
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the linearly polarized gluon distributions appear in the color dipole model as we derive the full cross sections of the DIS dijet production and the Drell-Yan dijet ($\gamma^*$ jet correlation) process. Together with the normal Weizs\"acker-Williams gluon distribution, the linearly polarized one will contribute to the DIS dijet production cross section as the coefficient of the $\cos(2 \Delta \phi) $ term in the correlation limit. We also derive the exact results for the cross section of the Drell-Yan dijet process, and find that the linearly polarized dipole gluon distribution which is identical to the normal dipole gluon distribution involves in the cross section. The results obtained in this paper agree with the previous transverse momentum dependent factorization study. We further derive the small-$x$ evolution of these linearly polarized gluon distributions and find that they rise as $x$ gets small at high energy.
[ { "created": "Wed, 28 Sep 2011 18:48:07 GMT", "version": "v1" }, { "created": "Tue, 31 Jan 2012 01:36:45 GMT", "version": "v2" } ]
2015-05-30
[ [ "Dominguez", "Fabio", "" ], [ "Qiu", "Jian-Wei", "" ], [ "Xiao", "Bo-Wen", "" ], [ "Yuan", "Feng", "" ] ]
We show that the linearly polarized gluon distributions appear in the color dipole model as we derive the full cross sections of the DIS dijet production and the Drell-Yan dijet ($\gamma^*$ jet correlation) process. Together with the normal Weizs\"acker-Williams gluon distribution, the linearly polarized one will contribute to the DIS dijet production cross section as the coefficient of the $\cos(2 \Delta \phi) $ term in the correlation limit. We also derive the exact results for the cross section of the Drell-Yan dijet process, and find that the linearly polarized dipole gluon distribution which is identical to the normal dipole gluon distribution involves in the cross section. The results obtained in this paper agree with the previous transverse momentum dependent factorization study. We further derive the small-$x$ evolution of these linearly polarized gluon distributions and find that they rise as $x$ gets small at high energy.
hep-ph/9405370
Leonid Burakovsky
L. Burakovsky and L.P. Horwitz
Relativistic mass distribution in event-anti-event system and ``realistic'' equation of state for hot hadronic matter
19 pages, report TAUP-2161-94
Found.Phys. 25 (1995) 1127-1146
10.1007/BF02055255
null
hep-ph hep-th
null
We find the equation of state $p,\rho \propto T^6,$ which gives the value of the sound velocity $c^2=0.20,$ in agreement with the ``realistic'' equation of state for hot hadronic matter suggested by Shuryak, in the framework of a covariant relativistic statistical mechanics of an event--anti-event system with small chemical and mass potentials. The relativistic mass distribution for such a system is obtained and shown to be a good candidate for fitting hadronic resonances, in agreement with the phenomenological models of Hagedorn, Shuryak, {\it et al.} This distribution provides a correction to the value of specific heat 3/2, of the order of 5.5\%, at low temperatures.
[ { "created": "Tue, 24 May 1994 11:35:15 GMT", "version": "v1" } ]
2009-10-28
[ [ "Burakovsky", "L.", "" ], [ "Horwitz", "L. P.", "" ] ]
We find the equation of state $p,\rho \propto T^6,$ which gives the value of the sound velocity $c^2=0.20,$ in agreement with the ``realistic'' equation of state for hot hadronic matter suggested by Shuryak, in the framework of a covariant relativistic statistical mechanics of an event--anti-event system with small chemical and mass potentials. The relativistic mass distribution for such a system is obtained and shown to be a good candidate for fitting hadronic resonances, in agreement with the phenomenological models of Hagedorn, Shuryak, {\it et al.} This distribution provides a correction to the value of specific heat 3/2, of the order of 5.5\%, at low temperatures.
1408.1811
Mustafa Amin
Kaloian D. Lozanov and Mustafa A. Amin
End of inflation, oscillons and matter-antimatter asymmetry
19 pages, 9 figures. v3: references added and minor changes in text. Published in Phys. Rev. D
Phys. Rev. D 90, 083528 (2014)
10.1103/PhysRevD.90.083528
null
hep-ph astro-ph.CO hep-th nlin.PS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dynamics at the end of inflation can generate an asymmetry between particles and anti-particles of the inflaton field. This asymmetry can be transferred to baryons via decays, generating a baryon asymmetry in our Universe. We explore this idea in detail for a complex inflaton governed by an observationally consistent -"flatter than quadratic"- potential with a weakly broken global U(1) symmetry. We find that most of the inflaton asymmetry is locked in non-topological soliton like configurations (oscillons) produced copiously at the end of inflation. These solitons eventually decay into baryons and generate the observed matter-antimatter asymmetry for a range of model parameters. Through a combination of three dimensional lattice simulations and a detailed linearized analysis, we show how the inflaton asymmetry depends on the fragmentation, the magnitude of the symmetry breaking term and initial conditions at the end of inflation. We discuss the final decay into baryons, but leave a detailed analysis of the inhomogeneous annihilation, reheating and thermalization to future work. As part of our work, we pay particular attention to generating multifield initial conditions for the field fluctuations (including metric perturbations) at the end of inflation for lattice simulations.
[ { "created": "Fri, 8 Aug 2014 10:40:53 GMT", "version": "v1" }, { "created": "Mon, 1 Sep 2014 18:56:44 GMT", "version": "v2" }, { "created": "Thu, 4 Dec 2014 14:20:04 GMT", "version": "v3" } ]
2014-12-05
[ [ "Lozanov", "Kaloian D.", "" ], [ "Amin", "Mustafa A.", "" ] ]
The dynamics at the end of inflation can generate an asymmetry between particles and anti-particles of the inflaton field. This asymmetry can be transferred to baryons via decays, generating a baryon asymmetry in our Universe. We explore this idea in detail for a complex inflaton governed by an observationally consistent -"flatter than quadratic"- potential with a weakly broken global U(1) symmetry. We find that most of the inflaton asymmetry is locked in non-topological soliton like configurations (oscillons) produced copiously at the end of inflation. These solitons eventually decay into baryons and generate the observed matter-antimatter asymmetry for a range of model parameters. Through a combination of three dimensional lattice simulations and a detailed linearized analysis, we show how the inflaton asymmetry depends on the fragmentation, the magnitude of the symmetry breaking term and initial conditions at the end of inflation. We discuss the final decay into baryons, but leave a detailed analysis of the inhomogeneous annihilation, reheating and thermalization to future work. As part of our work, we pay particular attention to generating multifield initial conditions for the field fluctuations (including metric perturbations) at the end of inflation for lattice simulations.
hep-ph/0607129
Shahida Dar
Shahida Dar, Qaisar Shafi, Arunansu Sil
Flux of Primordial Monopoles
17 pages, 4 figures, revtex4
Phys.Rev.D74:035013,2006
10.1103/PhysRevD.74.035013
BA-06-11
hep-ph
null
We discuss how in supersymmetric models with D and F-flat directions, a primordial monopole flux of order 10^{-16} - 10^{-18} cm^{-2} sec^{-1} sr^{-1} can coexist with the observed baryon asymmetry. A modified Affleck-Dine scenario yields the desired asymmetry if the monopoles are superheavy (~ 10^{13}-10^{18} GeV). For lighter monopoles with masses ~ 10^{9}-10^{12} GeV, the baryon asymmetry can arise via TeV scale leptogenesis.
[ { "created": "Tue, 11 Jul 2006 19:08:06 GMT", "version": "v1" } ]
2011-05-12
[ [ "Dar", "Shahida", "" ], [ "Shafi", "Qaisar", "" ], [ "Sil", "Arunansu", "" ] ]
We discuss how in supersymmetric models with D and F-flat directions, a primordial monopole flux of order 10^{-16} - 10^{-18} cm^{-2} sec^{-1} sr^{-1} can coexist with the observed baryon asymmetry. A modified Affleck-Dine scenario yields the desired asymmetry if the monopoles are superheavy (~ 10^{13}-10^{18} GeV). For lighter monopoles with masses ~ 10^{9}-10^{12} GeV, the baryon asymmetry can arise via TeV scale leptogenesis.
1611.05211
Guanghua Duan
Guang Hua Duan, Ken-ichi Hikasa, Lei Wu, Jin Min Yang, Mengchao Zhang
Leptonic mono-top from single stop production at LHC
15 pages, discussions added, version accepted by JHEP
null
10.1007/JHEP03(2017)091
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top squark (stop) can be produced via QCD interaction but also the electroweak interaction at the LHC. In this paper, we investigate the observability of the associated production of stop and chargino, $pp \to \tilde{t}_1\tilde{\chi}^-_1$, in compressed electroweakino scenario at the 14 TeV LHC. Due to the small mass-splitting between the lightest neutralino ($\tilde{\chi}^0_1$) and chargino ($\tilde{\chi}^-_1$), such a single stop production can give a mono-top signature through the stop decay $\tilde{t}_1 \to t \tilde{\chi}^0_1$. Focusing on the leptonic mono-top channel, we propose a lab-frame observable $\cos\theta_{b\ell}$ to reduce the SM backgrounds in virtue of a boosted top quark from the stop decay. We find that the single stop production can be probed at $2\sigma$ level at the HL-LHC for $m_{\tilde{t}_1}<760$ GeV and $m_{\tilde{\chi}^0_1}<150$ GeV.
[ { "created": "Wed, 16 Nov 2016 10:31:02 GMT", "version": "v1" }, { "created": "Mon, 13 Mar 2017 09:40:23 GMT", "version": "v2" } ]
2017-04-05
[ [ "Duan", "Guang Hua", "" ], [ "Hikasa", "Ken-ichi", "" ], [ "Wu", "Lei", "" ], [ "Yang", "Jin Min", "" ], [ "Zhang", "Mengchao", "" ] ]
Top squark (stop) can be produced via QCD interaction but also the electroweak interaction at the LHC. In this paper, we investigate the observability of the associated production of stop and chargino, $pp \to \tilde{t}_1\tilde{\chi}^-_1$, in compressed electroweakino scenario at the 14 TeV LHC. Due to the small mass-splitting between the lightest neutralino ($\tilde{\chi}^0_1$) and chargino ($\tilde{\chi}^-_1$), such a single stop production can give a mono-top signature through the stop decay $\tilde{t}_1 \to t \tilde{\chi}^0_1$. Focusing on the leptonic mono-top channel, we propose a lab-frame observable $\cos\theta_{b\ell}$ to reduce the SM backgrounds in virtue of a boosted top quark from the stop decay. We find that the single stop production can be probed at $2\sigma$ level at the HL-LHC for $m_{\tilde{t}_1}<760$ GeV and $m_{\tilde{\chi}^0_1}<150$ GeV.
1412.2724
Wan-Il Park
Gabriela Barenboim, Wan-Il Park
Spiral Inflation
5 pages, 7 figures, typos corrected, matched to journal version
null
10.1016/j.physletb.2014.12.042
FTUV-14-12-25, IFIC-14-79
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel scenario of primordial inflation in which the inflaton goes through a spiral motion starting from around the top of a symmetry breaking potential. We show that, even though inflation takes place for a field value much smaller than Planck scale, it is possible to obtain relatively large tensor to scalar ratio ($r \sim 0.1$) without fine tuning. The inflationary observables perfectly match Planck data.
[ { "created": "Mon, 8 Dec 2014 20:31:32 GMT", "version": "v1" }, { "created": "Tue, 16 Dec 2014 18:08:41 GMT", "version": "v2" }, { "created": "Wed, 21 Jan 2015 20:01:44 GMT", "version": "v3" } ]
2018-05-09
[ [ "Barenboim", "Gabriela", "" ], [ "Park", "Wan-Il", "" ] ]
We propose a novel scenario of primordial inflation in which the inflaton goes through a spiral motion starting from around the top of a symmetry breaking potential. We show that, even though inflation takes place for a field value much smaller than Planck scale, it is possible to obtain relatively large tensor to scalar ratio ($r \sim 0.1$) without fine tuning. The inflationary observables perfectly match Planck data.
hep-ph/0107139
Bojan Golli
Wojciech Broniowski, Bojan Golli, Georges Ripka
Solitons in nonlocal chiral quark models
42 pages, 8 figures, a new section presenting the results with the chiral-circle constraint
Nucl.Phys. A703 (2002) 667-701
10.1016/S0375-9474(01)01670-0
null
hep-ph nucl-th
null
Properties of hedgehog solitons in a chiral quark model with nonlocal regulators are described. We discuss the formation of the hedgehog soliton, the quantization of the baryon number, the energetic stability, the gauging and construction of Noether currents with help of path-ordered P-exponents, and the evaluation of observables. The issue of nonlocality is thoroughly discussed, with a focus on contributions to observables related to the Noether currents. It is shown that with typical model parameters the solitons are not far from the weak nonlocality limit. The methods developed are applicable to solitons in models with separable nonlocal four-fermion interactions.
[ { "created": "Thu, 12 Jul 2001 17:26:25 GMT", "version": "v1" }, { "created": "Wed, 7 Nov 2001 19:55:23 GMT", "version": "v2" } ]
2009-11-07
[ [ "Broniowski", "Wojciech", "" ], [ "Golli", "Bojan", "" ], [ "Ripka", "Georges", "" ] ]
Properties of hedgehog solitons in a chiral quark model with nonlocal regulators are described. We discuss the formation of the hedgehog soliton, the quantization of the baryon number, the energetic stability, the gauging and construction of Noether currents with help of path-ordered P-exponents, and the evaluation of observables. The issue of nonlocality is thoroughly discussed, with a focus on contributions to observables related to the Noether currents. It is shown that with typical model parameters the solitons are not far from the weak nonlocality limit. The methods developed are applicable to solitons in models with separable nonlocal four-fermion interactions.
hep-ph/0008293
Sharon Jensen
Prem P. Srivastava and Stanley J. Brodsky
Light-Front QCD in Light-Cone Gauge
Presented at VII Hadron Physics 2000, Caraguatatuba, Sao Paulo, Brazil, 10-15 April 2000
null
10.1142/9789812811653_0056
SLAC-PUB-8591
hep-ph
null
The light-front (LF) quantization of QCD in light-cone (l.c.) gauge is discussed. The Dirac method is employed to construct the LF Hamiltonian and theory quantized canonically. The Dyson-Wick perturbation theory expansion based on LF-time ordering is constructed. The framework incorporates in it simultaneously the Lorentz gauge condition as an operator equation as well. The propagator of the dynamical $\psi_+$ part of the free fermionic propagator is shown to be causal while the gauge field propagator is found to be transverse. The interaction Hamiltonian is re-expressed in the form closely resembling the one in covariant theory, except for additional instantaneous interactions, which can be treated systematically. Some explicit computations in QCD are given.
[ { "created": "Mon, 28 Aug 2000 22:28:55 GMT", "version": "v1" } ]
2017-08-23
[ [ "Srivastava", "Prem P.", "" ], [ "Brodsky", "Stanley J.", "" ] ]
The light-front (LF) quantization of QCD in light-cone (l.c.) gauge is discussed. The Dirac method is employed to construct the LF Hamiltonian and theory quantized canonically. The Dyson-Wick perturbation theory expansion based on LF-time ordering is constructed. The framework incorporates in it simultaneously the Lorentz gauge condition as an operator equation as well. The propagator of the dynamical $\psi_+$ part of the free fermionic propagator is shown to be causal while the gauge field propagator is found to be transverse. The interaction Hamiltonian is re-expressed in the form closely resembling the one in covariant theory, except for additional instantaneous interactions, which can be treated systematically. Some explicit computations in QCD are given.
1912.09843
Hee Sok Chung
Geoffrey T. Bodwin, Hee Sok Chung
New method for fitting coefficients in standard model effective theory
27 pages, 3 tables, minor clarifications, corrections, improvements in notation. Corresponds to published version
Phys. Rev. D 101, 115039 (2020)
10.1103/PhysRevD.101.115039
TUM-EFT 134/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an alternative method for carrying out a principal-component analysis of Wilson coefficients in standard model effective field theory (SMEFT). The method is based on singular-value decomposition (SVD). The SVD method provides information about the sensitivity of experimental observables to physics beyond the standard model that is not accessible in the Fisher-information method. In principle, the SVD method can also have computational advantages over diagonalization of the Fisher information matrix. We demonstrate the SVD method by applying it to the dimension-6 coefficients for the process of top-quark decay to a $b$ quark and a $W$ boson and use this example to illustrate some pitfalls in widely used fitting procedures. We also outline an iterative procedure for applying the SVD method to dimension-8 SMEFT coefficients.
[ { "created": "Fri, 20 Dec 2019 14:23:22 GMT", "version": "v1" }, { "created": "Fri, 24 Jan 2020 11:20:21 GMT", "version": "v2" }, { "created": "Sat, 18 Apr 2020 20:52:42 GMT", "version": "v3" }, { "created": "Fri, 5 Jun 2020 14:55:33 GMT", "version": "v4" }, { "created": "Thu, 2 Jul 2020 14:06:28 GMT", "version": "v5" } ]
2020-07-03
[ [ "Bodwin", "Geoffrey T.", "" ], [ "Chung", "Hee Sok", "" ] ]
We present an alternative method for carrying out a principal-component analysis of Wilson coefficients in standard model effective field theory (SMEFT). The method is based on singular-value decomposition (SVD). The SVD method provides information about the sensitivity of experimental observables to physics beyond the standard model that is not accessible in the Fisher-information method. In principle, the SVD method can also have computational advantages over diagonalization of the Fisher information matrix. We demonstrate the SVD method by applying it to the dimension-6 coefficients for the process of top-quark decay to a $b$ quark and a $W$ boson and use this example to illustrate some pitfalls in widely used fitting procedures. We also outline an iterative procedure for applying the SVD method to dimension-8 SMEFT coefficients.
hep-ph/0003252
Shinji Tsujikawa
S. Tsujikawa (Waseda University)
Particle production in the oscillating inflation model
18 pages, 14 figures
Phys.Rev.D61:083516,2000
10.1103/PhysRevD.61.083516
WU-AP/94/00
hep-ph astro-ph gr-qc hep-th
null
We investigate the particle production of a scalar field $\chi$ coupled to an inflaton field $\phi$ ($g^2\phi^2\chi^2/2$) in the {\it oscillating inflation} model, which was recently proposed by Damour and Mukhanov. Although the fluctuation of the $\phi$ field can be effectively enhanced during a stage of the oscillating inflation, the maximum fluctuation is suppressed as the critical value $\phi_c$ which indicates the scale of the core part of the inflaton potential decreases, in taking into account the back reaction effect of created particles. As for the $\chi$ particle production, we find that larger values of the coupling constant $g$ are required to lead to an efficient parametric resonance with the decrease of $\phi_c$, because an effective mass of inflaton around the minimum of its potential becomes larger. However, it is possible to generate the superheavy $\chi$ particle whose mass is greater than $10^{14}$ GeV, which would result in an important consequence for the GUT baryogenesis.
[ { "created": "Sun, 26 Mar 2000 05:18:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Tsujikawa", "S.", "", "Waseda University" ] ]
We investigate the particle production of a scalar field $\chi$ coupled to an inflaton field $\phi$ ($g^2\phi^2\chi^2/2$) in the {\it oscillating inflation} model, which was recently proposed by Damour and Mukhanov. Although the fluctuation of the $\phi$ field can be effectively enhanced during a stage of the oscillating inflation, the maximum fluctuation is suppressed as the critical value $\phi_c$ which indicates the scale of the core part of the inflaton potential decreases, in taking into account the back reaction effect of created particles. As for the $\chi$ particle production, we find that larger values of the coupling constant $g$ are required to lead to an efficient parametric resonance with the decrease of $\phi_c$, because an effective mass of inflaton around the minimum of its potential becomes larger. However, it is possible to generate the superheavy $\chi$ particle whose mass is greater than $10^{14}$ GeV, which would result in an important consequence for the GUT baryogenesis.
0710.4110
Javier Magnin
C. Avila, I. Monroy, J.C. Sanabria, J. Magnin
On the s-sbar asymmetry of the nucleon sea
6 pages, 2 figures
null
null
null
hep-ph
null
We study the $s-\bar s$ asymmetry in the nucleon sea using a model in which the proton wave function includes a Kaon-Hyperon Fock state. Parameters of the model are fixed by fitting the $s-\bar s$ asymmetry obtained from global fits to Deep Inelastic Scattering data. We discuss possible effects of the $s-\bar s$ asymmetry on the measurement of the Weinberg angle by the NuTeV Collaboration.
[ { "created": "Mon, 22 Oct 2007 17:18:37 GMT", "version": "v1" } ]
2007-10-23
[ [ "Avila", "C.", "" ], [ "Monroy", "I.", "" ], [ "Sanabria", "J. C.", "" ], [ "Magnin", "J.", "" ] ]
We study the $s-\bar s$ asymmetry in the nucleon sea using a model in which the proton wave function includes a Kaon-Hyperon Fock state. Parameters of the model are fixed by fitting the $s-\bar s$ asymmetry obtained from global fits to Deep Inelastic Scattering data. We discuss possible effects of the $s-\bar s$ asymmetry on the measurement of the Weinberg angle by the NuTeV Collaboration.
hep-ph/0209203
Ram Brustein
Irit Maor, Ram Brustein
Distinguishing among Scalar Field Models of Dark Energy
15 pages, 5 figures
Phys.Rev. D67 (2003) 103508
10.1103/PhysRevD.67.103508
null
hep-ph astro-ph
null
We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological constant (the value of the potential at its minimum) are degenerate with models with a positive or negative cosmological constant whose magnitude can be as large as the critical density. Adding information from CMB anisotropy measurements does reduce the degeneracy somewhat but not significantly. Our results indicate that a theoretical prior on the preferred form of the potential and the field's initial conditions may allow to quantitatively estimate model parameters from data. Without such a theoretical prior only limited qualitative information on the form and parameters of the potential can be extracted even from very accurate data.
[ { "created": "Wed, 18 Sep 2002 13:33:18 GMT", "version": "v1" } ]
2009-11-07
[ [ "Maor", "Irit", "" ], [ "Brustein", "Ram", "" ] ]
We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological constant (the value of the potential at its minimum) are degenerate with models with a positive or negative cosmological constant whose magnitude can be as large as the critical density. Adding information from CMB anisotropy measurements does reduce the degeneracy somewhat but not significantly. Our results indicate that a theoretical prior on the preferred form of the potential and the field's initial conditions may allow to quantitatively estimate model parameters from data. Without such a theoretical prior only limited qualitative information on the form and parameters of the potential can be extracted even from very accurate data.
0904.0921
Manuel Masip
Manuel Masip, Iacopo Mastromatteo
Cosmic-ray knee and flux of secondaries from interactions of cosmic rays with dark matter
Talk presented at 44th Rencontres de Moriond ("Very High Energy Phenomena in the Universe", La Thuile, Feb. 1-8 2009)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss possible implications of a large interaction cross section between cosmic rays and dark matter particles due to new physics at the TeV scale. In particular, in models with extra dimensions and a low fundamental scale of gravity the cross section grows very fast at transplanckian energies. We argue that the knee observed in the cosmic ray flux could be caused by such interactions. We show that this hypothesis implies a well defined flux of secondary gamma rays that seems consistent with MILAGRO observations.
[ { "created": "Mon, 6 Apr 2009 13:50:13 GMT", "version": "v1" } ]
2009-04-07
[ [ "Masip", "Manuel", "" ], [ "Mastromatteo", "Iacopo", "" ] ]
We discuss possible implications of a large interaction cross section between cosmic rays and dark matter particles due to new physics at the TeV scale. In particular, in models with extra dimensions and a low fundamental scale of gravity the cross section grows very fast at transplanckian energies. We argue that the knee observed in the cosmic ray flux could be caused by such interactions. We show that this hypothesis implies a well defined flux of secondary gamma rays that seems consistent with MILAGRO observations.
0710.1922
Bowen Xiao
Bo-Wen Xiao
On the anomalous dimensions of the multiple pomeron exchanges
26 pages, 7 figures. A few changes are made in Appendix F
Nucl.Phys.A798:132-164,2008
10.1016/j.nuclphysa.2007.10.013
null
hep-ph
null
High energy hard scattering in large $N_{c}$ limit can be described by the QCD dipole model. In this paper, single, double and triple BFKL pomeron exchange amplitudes are computed explicitly within the dipole model. Based on the calculation, the general formula $\gamma^{(k)*}_{0}=\chi^{-1}(k\chi({1/2}))$ which governs the anomalous dimension of $1\Rightarrow k$ amplitude is conjectured. As far as the unitarity problem is concerned, we find that the anomalous dimension $\gamma$ varies from graph to graph due to the DGLAP evolution. In the end, a comparison between this computation and reggeon field theory is provided.
[ { "created": "Wed, 10 Oct 2007 04:20:06 GMT", "version": "v1" }, { "created": "Fri, 12 Oct 2007 01:13:37 GMT", "version": "v2" }, { "created": "Tue, 20 Nov 2007 05:55:28 GMT", "version": "v3" } ]
2010-03-25
[ [ "Xiao", "Bo-Wen", "" ] ]
High energy hard scattering in large $N_{c}$ limit can be described by the QCD dipole model. In this paper, single, double and triple BFKL pomeron exchange amplitudes are computed explicitly within the dipole model. Based on the calculation, the general formula $\gamma^{(k)*}_{0}=\chi^{-1}(k\chi({1/2}))$ which governs the anomalous dimension of $1\Rightarrow k$ amplitude is conjectured. As far as the unitarity problem is concerned, we find that the anomalous dimension $\gamma$ varies from graph to graph due to the DGLAP evolution. In the end, a comparison between this computation and reggeon field theory is provided.
hep-ph/0307015
J. A. R. Cembranos
J.A.R. Cembranos, A. Dobado, A. L. Maroto
Living on a brane
4 pages, 1 figure. Proceedings of the 29th Spanish Physical Royal Society Biennial on the centennial of the society, Madrid, Spain, July 2003
RSEF Conf.Proc. M-30628 (2003) 808
null
null
hep-ph
null
We briefly review the distinctive signals of brane world models with low tension. We pay special attention to the brane fluctuations (branons), whose phenomenological consequences could be important both in high energy particle physics experiments and in astrophysical and cosmological observations.
[ { "created": "Tue, 1 Jul 2003 11:11:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cembranos", "J. A. R.", "" ], [ "Dobado", "A.", "" ], [ "Maroto", "A. L.", "" ] ]
We briefly review the distinctive signals of brane world models with low tension. We pay special attention to the brane fluctuations (branons), whose phenomenological consequences could be important both in high energy particle physics experiments and in astrophysical and cosmological observations.
2112.10618
Giovanni Barontini
G. Barontini, L. Blackburn, V. Boyer, F. Butuc-Mayer, X. Calmet, J. R. Crespo Lopez-Urrutia, E. A. Curtis, B. Darquie, J. Dunningham, N. J. Fitch, E. M. Forgan, K. Georgiou, P. Gill, R. M. Godun, J. Goldwin, V. Guarrera, A. C. Harwood, I. R. Hill, R. J. Hendricks, M. Jeong, M. Y. H. Johnson, M. Keller, L. P. Kozhiparambil Sajith, F. Kuipers, H. S. Margolis, C. Mayo, P. Newman, A. O. Parsons, L. Prokhorov, B. I. Robertson, J. Rodewald, M. S. Safronova, B. E. Sauer, M. Schioppo, N. Sherrill, Y. V. Stadnik, K. Szymaniec, M. R. Tarbutt, R. C. Thompson, A. Tofful, J. Tunesi, A. Vecchio, Y. Wang and S. Worm
Measuring the stability of fundamental constants with a network of clocks
null
EPJ Quantum Technology volume 9, Article number: 12 (2022)
10.1140/epjqt/s40507-022-00130-5
null
hep-ph astro-ph.CO gr-qc hep-ex physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The detection of variations of fundamental constants of the Standard Model would provide us with compelling evidence of new physics, and could lift the veil on the nature of dark matter and dark energy. In this work, we discuss how a network of atomic and molecular clocks can be used to look for such variations with unprecedented sensitivity over a wide range of time scales. This is precisely the goal of the recently launched QSNET project: A network of clocks for measuring the stability of fundamental constants. QSNET will include state-of-the-art atomic clocks, but will also develop next-generation molecular and highly charged ion clocks with enhanced sensitivity to variations of fundamental constants. We describe the technological and scientific aims of QSNET and evaluate its expected performance. We show that in the range of parameters probed by QSNET, either we will discover new physics, or we will impose new constraints on violations of fundamental symmetries and a range of theories beyond the Standard Model, including dark matter and dark energy models.
[ { "created": "Mon, 20 Dec 2021 15:31:35 GMT", "version": "v1" }, { "created": "Wed, 11 May 2022 11:12:17 GMT", "version": "v2" } ]
2022-05-12
[ [ "Barontini", "G.", "" ], [ "Blackburn", "L.", "" ], [ "Boyer", "V.", "" ], [ "Butuc-Mayer", "F.", "" ], [ "Calmet", "X.", "" ], [ "Lopez-Urrutia", "J. R. Crespo", "" ], [ "Curtis", "E. A.", "" ], [ "Darquie", "B.", "" ], [ "Dunningham", "J.", "" ], [ "Fitch", "N. J.", "" ], [ "Forgan", "E. M.", "" ], [ "Georgiou", "K.", "" ], [ "Gill", "P.", "" ], [ "Godun", "R. M.", "" ], [ "Goldwin", "J.", "" ], [ "Guarrera", "V.", "" ], [ "Harwood", "A. C.", "" ], [ "Hill", "I. R.", "" ], [ "Hendricks", "R. J.", "" ], [ "Jeong", "M.", "" ], [ "Johnson", "M. Y. H.", "" ], [ "Keller", "M.", "" ], [ "Sajith", "L. P. Kozhiparambil", "" ], [ "Kuipers", "F.", "" ], [ "Margolis", "H. S.", "" ], [ "Mayo", "C.", "" ], [ "Newman", "P.", "" ], [ "Parsons", "A. O.", "" ], [ "Prokhorov", "L.", "" ], [ "Robertson", "B. I.", "" ], [ "Rodewald", "J.", "" ], [ "Safronova", "M. S.", "" ], [ "Sauer", "B. E.", "" ], [ "Schioppo", "M.", "" ], [ "Sherrill", "N.", "" ], [ "Stadnik", "Y. V.", "" ], [ "Szymaniec", "K.", "" ], [ "Tarbutt", "M. R.", "" ], [ "Thompson", "R. C.", "" ], [ "Tofful", "A.", "" ], [ "Tunesi", "J.", "" ], [ "Vecchio", "A.", "" ], [ "Wang", "Y.", "" ], [ "Worm", "S.", "" ] ]
The detection of variations of fundamental constants of the Standard Model would provide us with compelling evidence of new physics, and could lift the veil on the nature of dark matter and dark energy. In this work, we discuss how a network of atomic and molecular clocks can be used to look for such variations with unprecedented sensitivity over a wide range of time scales. This is precisely the goal of the recently launched QSNET project: A network of clocks for measuring the stability of fundamental constants. QSNET will include state-of-the-art atomic clocks, but will also develop next-generation molecular and highly charged ion clocks with enhanced sensitivity to variations of fundamental constants. We describe the technological and scientific aims of QSNET and evaluate its expected performance. We show that in the range of parameters probed by QSNET, either we will discover new physics, or we will impose new constraints on violations of fundamental symmetries and a range of theories beyond the Standard Model, including dark matter and dark energy models.
1101.1832
Julien Baglio
J. Baglio, A. Djouadi, S. Ferrag and R.M. Godbole
The Tevatron Higgs exclusion limits and theoretical uncertainties: a critical appraisal
11 pages, 5 Figures. Version published in Physics Letter B, including an erratum
Phys.Lett.B699:368-371,2011; Erratum-ibid.B702:105-106,2011
10.1016/j.physletb.2011.04.039 10.1016/j.physletb.2011.06.074
CERN-PH-TH/2010-315, LPT-ORSAY-10-107
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the exclusion limits set by the CDF and D0 experiments on the Standard Model Higgs boson mass from their searches at the Tevatron in the light of large theoretical uncertainties on the signal and background cross sections. We show that when these uncertainties are consistently taken into account, the sensitivity of the experiments becomes significantly lower and the currently excluded mass range $M_H=158$-175 GeV would be entirely reopened. The necessary luminosity required to recover the current sensitivity is found to be a factor of two higher than the present one.
[ { "created": "Mon, 10 Jan 2011 14:40:53 GMT", "version": "v1" }, { "created": "Thu, 28 Apr 2011 17:24:13 GMT", "version": "v2" }, { "created": "Sat, 25 Jun 2011 07:39:25 GMT", "version": "v3" } ]
2011-07-26
[ [ "Baglio", "J.", "" ], [ "Djouadi", "A.", "" ], [ "Ferrag", "S.", "" ], [ "Godbole", "R. M.", "" ] ]
We examine the exclusion limits set by the CDF and D0 experiments on the Standard Model Higgs boson mass from their searches at the Tevatron in the light of large theoretical uncertainties on the signal and background cross sections. We show that when these uncertainties are consistently taken into account, the sensitivity of the experiments becomes significantly lower and the currently excluded mass range $M_H=158$-175 GeV would be entirely reopened. The necessary luminosity required to recover the current sensitivity is found to be a factor of two higher than the present one.
1705.08192
Ahmad Farzaneh Kord Dr
M. Haddadi Moghaddam, B. Azadegan, A. F. Kord and W. M. Alberico
Non-relativistic approximate numerical ideal-magneto hydrodynamics of (1+1) D transverse flow in Bjorken scenario
null
Eur.Phys.J. C78 (2018) no.3, 255
10.1140/epjc/s10052-018-5708-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, we investigate the impact of the magnetic field on the evolution of the transverse flow of QGP matter in the magneto-hydrodynamic (MHD) framework. We assume that the magnetic field is perpendicular to the reaction plane and then we solve the coupled Maxwell and conservation equations in (1+1D) transverse flow, within the Bjorken scenario. We consider a QGP with infinite electrical conductivity. First, the magnetic effects on the QGP medium at mid-rapidity are investigated at leading order; then the time and space dependence of the energy density, velocity and magnetic field in the transverse plane of the ideal magnetized hot plasma are obtained.
[ { "created": "Tue, 23 May 2017 11:39:06 GMT", "version": "v1" }, { "created": "Sun, 15 Oct 2017 09:38:21 GMT", "version": "v2" } ]
2019-12-03
[ [ "Moghaddam", "M. Haddadi", "" ], [ "Azadegan", "B.", "" ], [ "Kord", "A. F.", "" ], [ "Alberico", "W. M.", "" ] ]
In this study, we investigate the impact of the magnetic field on the evolution of the transverse flow of QGP matter in the magneto-hydrodynamic (MHD) framework. We assume that the magnetic field is perpendicular to the reaction plane and then we solve the coupled Maxwell and conservation equations in (1+1D) transverse flow, within the Bjorken scenario. We consider a QGP with infinite electrical conductivity. First, the magnetic effects on the QGP medium at mid-rapidity are investigated at leading order; then the time and space dependence of the energy density, velocity and magnetic field in the transverse plane of the ideal magnetized hot plasma are obtained.
2404.18667
Juliane Haug
Juliane Haug, Oliver Sch\"ule, and Fabian Wunder
A semi-analytical $x$-space solution for parton evolution -- Application to non-singlet and singlet DGLAP equation
29 pages, 11 figures, ancillary files with Mathematica and Python implementations of POMPOM, updated to match journal version
JHEP 07 (2024) 072
10.1007/JHEP07(2024)072
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a novel semi-analytical method for parton evolution. It is based on constructing a family of analytic functions spanning $x$-space which is closed under the considered evolution equation. Using these functions as a basis, the original integro-differential evolution equation transforms into a system of coupled ordinary differential equations, which can be solved numerically by restriction to a suitably chosen finite subsystem. The evolved distributions are obtained as analytic functions in $x$ with numerically obtained coefficients, providing insight into the analytic behavior of the evolved parton distributions. As a proof-of-principle, we apply our method to the leading order non-singlet and singlet DGLAP equation. Comparing our results to traditional Mellin-space methods, we find good agreement. The method is implemented in the code $\texttt{POMPOM}$ in $\texttt{Mathematica}$ as well as in $\texttt{Python}$.
[ { "created": "Mon, 29 Apr 2024 12:55:22 GMT", "version": "v1" }, { "created": "Tue, 30 Apr 2024 14:54:10 GMT", "version": "v2" }, { "created": "Mon, 10 Jun 2024 14:11:47 GMT", "version": "v3" }, { "created": "Fri, 2 Aug 2024 12:01:07 GMT", "version": "v4" } ]
2024-08-05
[ [ "Haug", "Juliane", "" ], [ "Schüle", "Oliver", "" ], [ "Wunder", "Fabian", "" ] ]
We present a novel semi-analytical method for parton evolution. It is based on constructing a family of analytic functions spanning $x$-space which is closed under the considered evolution equation. Using these functions as a basis, the original integro-differential evolution equation transforms into a system of coupled ordinary differential equations, which can be solved numerically by restriction to a suitably chosen finite subsystem. The evolved distributions are obtained as analytic functions in $x$ with numerically obtained coefficients, providing insight into the analytic behavior of the evolved parton distributions. As a proof-of-principle, we apply our method to the leading order non-singlet and singlet DGLAP equation. Comparing our results to traditional Mellin-space methods, we find good agreement. The method is implemented in the code $\texttt{POMPOM}$ in $\texttt{Mathematica}$ as well as in $\texttt{Python}$.
1605.03224
Fei Teng
Jason Kumar, Pearl Sandick, Fei Teng and Takahiro Yamamoto
Gamma-ray Signals from Dark Matter Annihilation Via Charged Mediators
34 pages, 27 figures. One reference added. Published version
Phys. Rev. D 94, 015022 (2016)
10.1103/PhysRevD.94.015022
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a simplified model in which Majorana fermion dark matter annihilates to charged fermions through exchange of charged mediators. We consider the gamma-ray signals arising from the processes $XX \rightarrow \bar f f \gamma$, $\gamma \gamma$, and $\gamma Z$ in the most general case, including non-trivial fermion mass and non-trivial left-right mixing and $CP$-violating phase for the charged mediators. In particular, we find the most general spectrum for internal bremsstrahlung, which interpolates between the regimes dominated by virtual internal bremsstrahlung and by final state radiation. We also examine the variation in the ratio $\sigma(\gamma \gamma) / \sigma (\gamma Z)$ and the helicity asymmetry in the $XX \rightarrow \gamma \gamma$ process, each as a function of mixing angle and $CP$-violating phase. As an application, we apply these results to searches for a class of MSSM models.
[ { "created": "Tue, 10 May 2016 21:53:39 GMT", "version": "v1" }, { "created": "Tue, 19 Jul 2016 06:12:29 GMT", "version": "v2" } ]
2016-07-27
[ [ "Kumar", "Jason", "" ], [ "Sandick", "Pearl", "" ], [ "Teng", "Fei", "" ], [ "Yamamoto", "Takahiro", "" ] ]
We consider a simplified model in which Majorana fermion dark matter annihilates to charged fermions through exchange of charged mediators. We consider the gamma-ray signals arising from the processes $XX \rightarrow \bar f f \gamma$, $\gamma \gamma$, and $\gamma Z$ in the most general case, including non-trivial fermion mass and non-trivial left-right mixing and $CP$-violating phase for the charged mediators. In particular, we find the most general spectrum for internal bremsstrahlung, which interpolates between the regimes dominated by virtual internal bremsstrahlung and by final state radiation. We also examine the variation in the ratio $\sigma(\gamma \gamma) / \sigma (\gamma Z)$ and the helicity asymmetry in the $XX \rightarrow \gamma \gamma$ process, each as a function of mixing angle and $CP$-violating phase. As an application, we apply these results to searches for a class of MSSM models.
hep-ph/0005097
W. Des Ramsay
Willem T.H. van Oers (University of Manitoba, Canada)
Constraints on a Parity-even/Time-Reversal-odd Interaction
7 Pages LaTeX, 2 PostScript figures, uses aipproc.sty. Written version of Invited Paper presented at the 3rd International Symposium on Symmetries in Subatomic Physics, Adelaide, SA, Australia, March 13-17, 2000
AIP Conf.Proc. 539 (2000) 66-72
10.1063/1.1330903
TRI-PP-00-18
hep-ph
null
Time-Reversal-Invariance non-conservation has for the first time been unequivocally demonstrated in a direct measurement, one of the results of the CPLEAR experiment. What is the situation then with regard to time-reversal-invariance non-conservation in systems other than the neutral kaon system? Two classes of tests of time-reversal-invariance need to be distinguished: the first one deals with parity violating (P-odd)/time-reversal-invariance non-conserving (T-odd) interactions, while the second one deals with P-even/T-odd interactions (assuming CPT conservation this implies C-conjugation non-conservation). Limits on a P-odd/T-odd interaction follow from measurements of the electric dipole moment of the neutron. This in turn provides a limit on a P-odd/T-odd pion-nucleon coupling constant which is 10^-4 times the weak interaction strength. Limits on a P-even/T-odd interaction are much less stringent. The better constraint stems also from the measurement of the electric dipole moment of the neutron. Of all the other tests, measurements of charge-symmetry breaking in neutron-proton elastic scattering provide the next better constraint. The latter experiments were performed at TRIUMF (at 477 and 347 MeV) and at IUCF (at 183 MeV). Weak decay experiments (the transverse polarization of the muon in K+ -> pi0 mu+ nu and the transverse polarization of the positrons in polarized muon decay) have the potential to provide comparable or possibly better constraints.
[ { "created": "Wed, 10 May 2000 22:37:16 GMT", "version": "v1" } ]
2009-10-31
[ [ "van Oers", "Willem T. H.", "", "University of Manitoba, Canada" ] ]
Time-Reversal-Invariance non-conservation has for the first time been unequivocally demonstrated in a direct measurement, one of the results of the CPLEAR experiment. What is the situation then with regard to time-reversal-invariance non-conservation in systems other than the neutral kaon system? Two classes of tests of time-reversal-invariance need to be distinguished: the first one deals with parity violating (P-odd)/time-reversal-invariance non-conserving (T-odd) interactions, while the second one deals with P-even/T-odd interactions (assuming CPT conservation this implies C-conjugation non-conservation). Limits on a P-odd/T-odd interaction follow from measurements of the electric dipole moment of the neutron. This in turn provides a limit on a P-odd/T-odd pion-nucleon coupling constant which is 10^-4 times the weak interaction strength. Limits on a P-even/T-odd interaction are much less stringent. The better constraint stems also from the measurement of the electric dipole moment of the neutron. Of all the other tests, measurements of charge-symmetry breaking in neutron-proton elastic scattering provide the next better constraint. The latter experiments were performed at TRIUMF (at 477 and 347 MeV) and at IUCF (at 183 MeV). Weak decay experiments (the transverse polarization of the muon in K+ -> pi0 mu+ nu and the transverse polarization of the positrons in polarized muon decay) have the potential to provide comparable or possibly better constraints.
hep-ph/9711431
Peter Minkowski
P. Minkowski
Note on the Mass Square of the Eta' Meson
8 pages
Phys.Lett. B423 (1998) 157-161
10.1016/S0370-2693(98)00130-0
BUTP-97/35
hep-ph
null
We propose to use as a mathematical tool to study the mass square of the etaprime meson an infinitely heavy supplementary quark flavor Q. This is understood in the framework of QCD with one light quark flavor (or n_fl light flavors) and the gauge group SU3 colour (or SUN colour). The full system thus consists of n_fl + 1 flavors, including the infinitely heavy one. The purpose of this note is to show how the heavy flavor can be made to represent the anomalies of the subtheory describing the remnant physical degrees of freedom. In the large N_c limit the mass square of etaprime tends to a finite limit. The essential deviations from (semi) perturbative derivations are related to simple properties of the 'heavy' flavor.
[ { "created": "Mon, 24 Nov 1997 08:05:52 GMT", "version": "v1" } ]
2009-10-30
[ [ "Minkowski", "P.", "" ] ]
We propose to use as a mathematical tool to study the mass square of the etaprime meson an infinitely heavy supplementary quark flavor Q. This is understood in the framework of QCD with one light quark flavor (or n_fl light flavors) and the gauge group SU3 colour (or SUN colour). The full system thus consists of n_fl + 1 flavors, including the infinitely heavy one. The purpose of this note is to show how the heavy flavor can be made to represent the anomalies of the subtheory describing the remnant physical degrees of freedom. In the large N_c limit the mass square of etaprime tends to a finite limit. The essential deviations from (semi) perturbative derivations are related to simple properties of the 'heavy' flavor.
1603.09152
Manjit Kaur Dr.
M. Kaur and Ruchi Gupta
Parton level study of high ET jets in hard QCD processes at LHC
5 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inclusive jet production will dominate the high $Q^{2}$ final states at the LHC.~In this work we try to estimate the up-to-date expectations, for high $E_{T}$ jets and their expected origin from the various parton-parton scattering processes. For these studies we have used a standard Parton Distribution Function (PDF) and simulated millions of events with the PYTHIA8 event genertor. The results are compared with simulations for center-of-mass energies of 0.9 TeV, 2.36 TeV, 7 TeV and 14 TeV corresponding to existing and future LHC runs. We present some expectations for the relative cross sections of different quark flavours which indicates that eventually we might be able to measure the cross section for b-flavoured jets with reasonable accuracy up to an $E_T$ of a few TeV.
[ { "created": "Wed, 30 Mar 2016 12:23:27 GMT", "version": "v1" } ]
2016-03-31
[ [ "Kaur", "M.", "" ], [ "Gupta", "Ruchi", "" ] ]
Inclusive jet production will dominate the high $Q^{2}$ final states at the LHC.~In this work we try to estimate the up-to-date expectations, for high $E_{T}$ jets and their expected origin from the various parton-parton scattering processes. For these studies we have used a standard Parton Distribution Function (PDF) and simulated millions of events with the PYTHIA8 event genertor. The results are compared with simulations for center-of-mass energies of 0.9 TeV, 2.36 TeV, 7 TeV and 14 TeV corresponding to existing and future LHC runs. We present some expectations for the relative cross sections of different quark flavours which indicates that eventually we might be able to measure the cross section for b-flavoured jets with reasonable accuracy up to an $E_T$ of a few TeV.
0804.1521
Stefano Morisi
M.Hirsch, S.Morisi and J.W.F.Valle
Tri-bimaximal neutrino mixing and neutrinoless double beta decay
4 pages and 3 figures
Phys.Rev.D78:093007,2008
10.1103/PhysRevD.78.093007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a tri-bimaximal lepton mixing scheme where the neutrinoless double beta decay rate (bb0v) has a lower bound which correlates with the ratio alpha = Dmsol/Dmatm well determined by current data, as well as with the unknown Majorana CP phase phi12 characterizing the solar neutrino sub-system. For the special value phi12 = pi/2 (opposite CP-sign neutrinos) the bb0v rate vanishes at tree level when Dmsol/Dmatm = 3/80, only allowed at 3 sigma. For all other cases the rate is nonzero, and lies within current and projected experimental sensitivities close to phi12=0. We suggest two model realizations of this scheme in terms of an A4xZ2 and A4xZ4 flavour symmetries.
[ { "created": "Wed, 9 Apr 2008 19:32:18 GMT", "version": "v1" } ]
2008-12-18
[ [ "Hirsch", "M.", "" ], [ "Morisi", "S.", "" ], [ "Valle", "J. W. F.", "" ] ]
We present a tri-bimaximal lepton mixing scheme where the neutrinoless double beta decay rate (bb0v) has a lower bound which correlates with the ratio alpha = Dmsol/Dmatm well determined by current data, as well as with the unknown Majorana CP phase phi12 characterizing the solar neutrino sub-system. For the special value phi12 = pi/2 (opposite CP-sign neutrinos) the bb0v rate vanishes at tree level when Dmsol/Dmatm = 3/80, only allowed at 3 sigma. For all other cases the rate is nonzero, and lies within current and projected experimental sensitivities close to phi12=0. We suggest two model realizations of this scheme in terms of an A4xZ2 and A4xZ4 flavour symmetries.
hep-ph/0001139
Lynne Orr
Lynne H. Orr (Rochester) and W.J. Stirling (Durham)
BFKL Monte Carlo for Dijet Production at Hadron Colliders
3 pages including 2 figures, Latex, uses fleqn,epsfig,run2col; contribution to the proceedings of the Fermilab Run II Workshop, QCD and Weak Boson Physics
null
null
UR-1599
hep-ph
null
The production of jet pairs at large rapidity difference at hadron colliders is potentially sensitive to BFKL physics. We present the results of a BFKL Monte Carlo calculation of dijets at the Tevatron. The Monte Carlo incorporates kinematic effects that are absent in analytic BFKL calculations; these effects significantly modify the behavior of dijet cross sections.
[ { "created": "Fri, 14 Jan 2000 21:35:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Orr", "Lynne H.", "", "Rochester" ], [ "Stirling", "W. J.", "", "Durham" ] ]
The production of jet pairs at large rapidity difference at hadron colliders is potentially sensitive to BFKL physics. We present the results of a BFKL Monte Carlo calculation of dijets at the Tevatron. The Monte Carlo incorporates kinematic effects that are absent in analytic BFKL calculations; these effects significantly modify the behavior of dijet cross sections.
1706.04598
Bhavesh Chauhan
Bhavesh Chauhan, Bharti Kindra, Ashish Narang
Discrepancies in simultaneous explanation of Flavor Anomalies and IceCube PeV Events using Leptoquarks
References updated; Conclusion Changed; Matches published version
Phys. Rev. D 97, 095007 (2018)
10.1103/PhysRevD.97.095007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we show that the scalar doublet Leptoquark with Hypercharge 7/6 can simultaneously explain the recent measurement of $R_{K}$, $R_{K^*}$, the excess in anomalous magnetic moment of muon, and the observed excess in IceCube HESE data. For appropriate choice of couplings, the flavor anomalies are generated at one-loop level and IceCube data is explained via resonant production of the Leptoquark. Several constraints from LHC searches are imposed on the model parameter space.
[ { "created": "Wed, 14 Jun 2017 17:32:11 GMT", "version": "v1" }, { "created": "Thu, 29 Jun 2017 07:40:16 GMT", "version": "v2" }, { "created": "Wed, 16 May 2018 08:10:55 GMT", "version": "v3" } ]
2018-05-23
[ [ "Chauhan", "Bhavesh", "" ], [ "Kindra", "Bharti", "" ], [ "Narang", "Ashish", "" ] ]
Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we show that the scalar doublet Leptoquark with Hypercharge 7/6 can simultaneously explain the recent measurement of $R_{K}$, $R_{K^*}$, the excess in anomalous magnetic moment of muon, and the observed excess in IceCube HESE data. For appropriate choice of couplings, the flavor anomalies are generated at one-loop level and IceCube data is explained via resonant production of the Leptoquark. Several constraints from LHC searches are imposed on the model parameter space.
1304.0202
Mikko Laine
M. Laine
Thermal 2-loop master spectral function at finite momentum
29 pages. v2: numerics improved; to appear in JHEP
null
10.1007/JHEP05(2013)083
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When considering NLO corrections to thermal particle production in the "relativistic" regime, in which the invariant mass squared of the produced particle is K^2 ~ (pi T)^2, then the production rate can be expressed as a sum of a few universal "master" spectral functions. Taking the most complicated 2-loop master as an example, a general strategy for obtaining a convergent 2-dimensional integral representation is suggested. The analysis applies both to bosonic and fermionic statistics, and shows that for this master the non-relativistic approximation is only accurate for K^2 > (8 pi T)^2, whereas the zero-momentum approximation works surprisingly well. Once the simpler masters have been similarly resolved, NLO results for quantities such as the right-handed neutrino production rate from a Standard Model plasma or the dilepton production rate from a QCD plasma can be assembled for K^2 ~ (pi T)^2.
[ { "created": "Sun, 31 Mar 2013 13:07:19 GMT", "version": "v1" }, { "created": "Thu, 2 May 2013 07:03:41 GMT", "version": "v2" } ]
2015-06-15
[ [ "Laine", "M.", "" ] ]
When considering NLO corrections to thermal particle production in the "relativistic" regime, in which the invariant mass squared of the produced particle is K^2 ~ (pi T)^2, then the production rate can be expressed as a sum of a few universal "master" spectral functions. Taking the most complicated 2-loop master as an example, a general strategy for obtaining a convergent 2-dimensional integral representation is suggested. The analysis applies both to bosonic and fermionic statistics, and shows that for this master the non-relativistic approximation is only accurate for K^2 > (8 pi T)^2, whereas the zero-momentum approximation works surprisingly well. Once the simpler masters have been similarly resolved, NLO results for quantities such as the right-handed neutrino production rate from a Standard Model plasma or the dilepton production rate from a QCD plasma can be assembled for K^2 ~ (pi T)^2.
1303.2740
Yutaka Ookouchi
Kohei Kamada, Tatsuo Kobayashi, Keisuke Ohashi and Yutaka Ookouchi
Cosmic R-string in thermal history
28 pages, 11 figures, v2: references added
null
10.1007/JHEP05(2013)091
KUNS-2437, DESY 13-033, OCU-PHYS-381
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study stabilization of an unstable cosmic string associated with spontaneously broken $U(1)_R$ symmetry, which otherwise causes a dangerous roll-over process. We demonstrate that in a gauge mediation model, messengers can receive enough corrections from the thermal plasma of the supersymmetric standard model particles to stabilize the unstable modes of the string.
[ { "created": "Tue, 12 Mar 2013 01:17:27 GMT", "version": "v1" }, { "created": "Thu, 2 May 2013 05:50:53 GMT", "version": "v2" } ]
2015-06-15
[ [ "Kamada", "Kohei", "" ], [ "Kobayashi", "Tatsuo", "" ], [ "Ohashi", "Keisuke", "" ], [ "Ookouchi", "Yutaka", "" ] ]
We study stabilization of an unstable cosmic string associated with spontaneously broken $U(1)_R$ symmetry, which otherwise causes a dangerous roll-over process. We demonstrate that in a gauge mediation model, messengers can receive enough corrections from the thermal plasma of the supersymmetric standard model particles to stabilize the unstable modes of the string.
1207.0331
German Rodrigo
German Rodrigo
The ttbar asymmetry in the Standard Model and beyond
8 pages. Contribution to the proceedings of the 47th Renc\^ontres de Moriond, EW 2012 session
null
null
LPN12-074; IFIC/12-47
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A sizable charge asymmetry in top quark pair production has been observed at the Tevatron. The experimental results seem to exceed systematically the Standard Model theory predictions by a significant amount and have triggered a large number of suggestions for 'new physics'. The effect is also visible at the LHC, and preliminary results have already been presented by the ATLAS and CMS collaborations. In this talk, we review the present status of the theoretical predictions, and their comparison with the experimental measurements.
[ { "created": "Mon, 2 Jul 2012 10:38:46 GMT", "version": "v1" } ]
2012-07-03
[ [ "Rodrigo", "German", "" ] ]
A sizable charge asymmetry in top quark pair production has been observed at the Tevatron. The experimental results seem to exceed systematically the Standard Model theory predictions by a significant amount and have triggered a large number of suggestions for 'new physics'. The effect is also visible at the LHC, and preliminary results have already been presented by the ATLAS and CMS collaborations. In this talk, we review the present status of the theoretical predictions, and their comparison with the experimental measurements.
hep-ph/0212325
Leutwyler
H. Leutwyler (University of Bern)
Strong Interactions at Low Energy
Lectures given at the school of physics "Understanding the structure of hadrons", Prague, July 2001, 20 pp
Czech.J.Phys. 52 (2002) B9-B27
10.1007/s10582-002-0077-1
null
hep-ph
null
The lectures review some of the basic concepts relevant for an understanding of the low energy properties of the strong interactions: chiral symmetry, spontaneous symmetry breakdown, Goldstone bosons, quark condensate. The effective field theory used to analyze the low energy structure is briefly sketched. As an illustration, I discuss the implications of the recent data on the decay $K\to \pi\pi e\nu$ for the magnitude of the quark condensate.
[ { "created": "Fri, 20 Dec 2002 23:55:10 GMT", "version": "v1" } ]
2015-06-25
[ [ "Leutwyler", "H.", "", "University of Bern" ] ]
The lectures review some of the basic concepts relevant for an understanding of the low energy properties of the strong interactions: chiral symmetry, spontaneous symmetry breakdown, Goldstone bosons, quark condensate. The effective field theory used to analyze the low energy structure is briefly sketched. As an illustration, I discuss the implications of the recent data on the decay $K\to \pi\pi e\nu$ for the magnitude of the quark condensate.
1012.1595
Mu-Chun Chen
Mu-Chun Chen, K.T. Mahanthappa
Models and Phenomenology of Neutrino Masses circa 2010
Plenary Talk presented at the XXIV International Conference on Neutrino Physics and Astrophysics (Neutrino 2010), Athens, Greece, June 14-19, 2010; v2: content expanded; 5 pages, no figure
null
null
COLO-HEP-560; UCI-TR-2010-32
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review recent developments in models of neutrino masses and mixing. Emphases are given to models based on finite group family symmetries from which the tri-bimaximal neutrino mixing can arise. In particular, we describe one recent model based on SUSY SU(5) combined with a family symmetry based on the double tetrahedral group, T'. All 22 observable fermion masses and mixing angles and CP violating measures are fitted with only 9 parameters. In this model, a near tri-bimaximal MNS matrix and a realistic CKM matrix are simultaneously generated; the MNS matrix gets slightly modified by virtue of having the Georgi-Jarlskog relations. Due to the presence of complex Clebsch-Gordan coefficients in T', CP violation in this model is entirely geometrical in origin. The prediction of the model for the leptonic Dirac CP phase is 227 degrees, which turns out to be very close to the current best fit value of 220 degrees from SuperK.
[ { "created": "Tue, 7 Dec 2010 21:00:00 GMT", "version": "v1" }, { "created": "Thu, 9 Dec 2010 18:56:30 GMT", "version": "v2" } ]
2015-03-17
[ [ "Chen", "Mu-Chun", "" ], [ "Mahanthappa", "K. T.", "" ] ]
We review recent developments in models of neutrino masses and mixing. Emphases are given to models based on finite group family symmetries from which the tri-bimaximal neutrino mixing can arise. In particular, we describe one recent model based on SUSY SU(5) combined with a family symmetry based on the double tetrahedral group, T'. All 22 observable fermion masses and mixing angles and CP violating measures are fitted with only 9 parameters. In this model, a near tri-bimaximal MNS matrix and a realistic CKM matrix are simultaneously generated; the MNS matrix gets slightly modified by virtue of having the Georgi-Jarlskog relations. Due to the presence of complex Clebsch-Gordan coefficients in T', CP violation in this model is entirely geometrical in origin. The prediction of the model for the leptonic Dirac CP phase is 227 degrees, which turns out to be very close to the current best fit value of 220 degrees from SuperK.
hep-ph/9509219
Jakub Rembielinski
J. Rembielinski
Quantization of the tachyonic field and the preferred frame
LaTeX2e or Latex 2.09, 24pp.; 2 references added, formulae (26), (27), (31) corrected
null
null
null
hep-ph gr-qc hep-th
null
A consistent quantization scheme for imaginary-mass field is proposed. It is related to an appropriate choice of the synchronization procedure (definition of time), which guarantee an absolute causality in agreement with Lorentz covariance. In that formulation a possible existence of field excitations (tachyons) distinguish an inertial frame (tachyon privileged frame of reference) {\em via} spontaneous breaking of the so called synchronization group. In this scheme relativity principle is broken but Lorentz symmetry is exactly preserved in agreement with local properties of the observed world.
[ { "created": "Mon, 4 Sep 1995 20:45:26 GMT", "version": "v1" }, { "created": "Fri, 15 Sep 1995 18:18:01 GMT", "version": "v2" } ]
2008-02-03
[ [ "Rembielinski", "J.", "" ] ]
A consistent quantization scheme for imaginary-mass field is proposed. It is related to an appropriate choice of the synchronization procedure (definition of time), which guarantee an absolute causality in agreement with Lorentz covariance. In that formulation a possible existence of field excitations (tachyons) distinguish an inertial frame (tachyon privileged frame of reference) {\em via} spontaneous breaking of the so called synchronization group. In this scheme relativity principle is broken but Lorentz symmetry is exactly preserved in agreement with local properties of the observed world.
hep-ph/0208114
Michael Luke
Aida X. El-Khadra and Michael Luke
The Mass of the b Quark
54 pages, 5 figures. With permission from the Annual Review of Nuclear & Particle Science. Final version of this material is scheduled to appear in the Annual Review of Nuclear & Particle Science, Vol. 52, to be published in December 2002 by Annual Reviews (http://AnnualReviews.org)
Ann.Rev.Nucl.Part.Sci.52:201-251,2002
10.1146/annurev.nucl.52.050102.090710
null
hep-ph
null
We review the current status of determinations of the b-quark mass, m_b. We describe the theoretical tools required for determining m_b, with particular emphasis on effective field theories both in the continuum and on the lattice. We present several definitions of m_b and highlight their advantages and disadvantages. Finally, we discuss the determinations of m_b from b-bar b systems, b-flavored hadrons, and high-energy processes, with careful attention to the corresponding theoretical uncertainties.
[ { "created": "Mon, 12 Aug 2002 19:22:29 GMT", "version": "v1" } ]
2008-11-26
[ [ "El-Khadra", "Aida X.", "" ], [ "Luke", "Michael", "" ] ]
We review the current status of determinations of the b-quark mass, m_b. We describe the theoretical tools required for determining m_b, with particular emphasis on effective field theories both in the continuum and on the lattice. We present several definitions of m_b and highlight their advantages and disadvantages. Finally, we discuss the determinations of m_b from b-bar b systems, b-flavored hadrons, and high-energy processes, with careful attention to the corresponding theoretical uncertainties.
hep-ph/0001212
Passarino Giampiero
G. Passarino (Turin Univ. and INFN Turin)
Single-W Production and Fermion-Loop Scheme: Numerical Results
27 pages(Latex), 7 figures
Nucl.Phys. B578 (2000) 3-26
10.1016/S0550-3213(00)00172-3
null
hep-ph hep-ex
null
The single-W production mechanism is synonymous to the electron-positron annihilation into electron, neutrino and a W boson with the outgoing electron lost in a small cone around the beam direction. It requires a Renormalization Scheme that preserves gauge invariance and fermion masses cannot be neglected in the calculation. A recently proposed generalization of the so-called Fermion-Loop scheme is applied to the evaluation of observables at LEP 2 energies. Single-W processes are dominated by a regime of low momentum transfer of the outgoing electron and any high-energy Renormalization Scheme fails to give the correct description of the scale. The Fermion-Loop scheme automatically converts all couplings of the theory into couplings that are running at the appropriate scale. Therefore, in addition to represent the only scheme fully justified on a field-theoretical basis, the Fermion-Loop is the best starting point to include radiative corrections into single-W production. Numerical results are presented, showing a decrease in the predictions that can be sizeable. There is no naive and overall rescaling of the e.m. coupling constant, in any pragmatic scheme, that can reproduce the Fermion-Loop results, at the requested accuracy, for all configurations and for all kinematical cuts.
[ { "created": "Thu, 20 Jan 2000 14:53:20 GMT", "version": "v1" } ]
2009-10-31
[ [ "Passarino", "G.", "", "Turin Univ. and INFN Turin" ] ]
The single-W production mechanism is synonymous to the electron-positron annihilation into electron, neutrino and a W boson with the outgoing electron lost in a small cone around the beam direction. It requires a Renormalization Scheme that preserves gauge invariance and fermion masses cannot be neglected in the calculation. A recently proposed generalization of the so-called Fermion-Loop scheme is applied to the evaluation of observables at LEP 2 energies. Single-W processes are dominated by a regime of low momentum transfer of the outgoing electron and any high-energy Renormalization Scheme fails to give the correct description of the scale. The Fermion-Loop scheme automatically converts all couplings of the theory into couplings that are running at the appropriate scale. Therefore, in addition to represent the only scheme fully justified on a field-theoretical basis, the Fermion-Loop is the best starting point to include radiative corrections into single-W production. Numerical results are presented, showing a decrease in the predictions that can be sizeable. There is no naive and overall rescaling of the e.m. coupling constant, in any pragmatic scheme, that can reproduce the Fermion-Loop results, at the requested accuracy, for all configurations and for all kinematical cuts.
1502.05409
Daniel Stolarski
Pedro Schwaller, Daniel Stolarski, and Andreas Weiler
Emerging Jets
45 pages, 22 figures. v2: Typos fixed. v3: Minor modifications, references added, version accepted in JHEP. Supplementary code can be found at github.com/pedroschwaller/EmergingJets
null
10.1007/JHEP05(2015)059
CERN-PH-TH-2015-031, DESY 15-026
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.
[ { "created": "Wed, 18 Feb 2015 21:00:15 GMT", "version": "v1" }, { "created": "Tue, 24 Feb 2015 14:04:15 GMT", "version": "v2" }, { "created": "Mon, 11 May 2015 08:02:07 GMT", "version": "v3" } ]
2015-05-19
[ [ "Schwaller", "Pedro", "" ], [ "Stolarski", "Daniel", "" ], [ "Weiler", "Andreas", "" ] ]
In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.
1605.09378
Antonio Racioppi
Kristjan Kannike, Antonio Racioppi and Martti Raidal
Super-Heavy Dark Matter - Towards Predictive Scenarios from Inflation
10 pages, 4 figures. Matches the published version on NPB
Nuclear Physics B 918 (2017) 162-177
10.1016/j.nuclphysb.2017.02.019
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A generic prediction of the Coleman-Weinberg inflation is the existence of a heavy particle sector whose interactions with the inflaton, the lightest state in this sector, generate the inflaton potential at loop level. For typical interactions the heavy sector may contain stable states whose relic abundance is generated at the end of inflation by the gravity alone. This general feature, and the absence of any particle physics signal of dark matter so far, motivates us to look for new directions in the dark sector physics, including scenarios in which dark matter is super-heavy. In this article we study the possibility that the dark matter is even heavier than the inflaton, its existence follows from the inflaton dynamics, and its abundance today is {\it naturally} determined by the weakness of gravitational interaction. This implies that the super-heavy dark matter scenarios can be tested via the measurements of inflationary parameters and/or the CMB isocurvature perturbations and non-Gaussianities. We explicitly work out details of three Coleman-Weinberg inflation scenarios, study the systematics of super-heavy dark matter production in those cases, and compute which parts of the parameter spaces can be probed by the future CMB measurements.
[ { "created": "Mon, 30 May 2016 20:00:01 GMT", "version": "v1" }, { "created": "Fri, 17 Mar 2017 15:24:53 GMT", "version": "v2" } ]
2017-03-20
[ [ "Kannike", "Kristjan", "" ], [ "Racioppi", "Antonio", "" ], [ "Raidal", "Martti", "" ] ]
A generic prediction of the Coleman-Weinberg inflation is the existence of a heavy particle sector whose interactions with the inflaton, the lightest state in this sector, generate the inflaton potential at loop level. For typical interactions the heavy sector may contain stable states whose relic abundance is generated at the end of inflation by the gravity alone. This general feature, and the absence of any particle physics signal of dark matter so far, motivates us to look for new directions in the dark sector physics, including scenarios in which dark matter is super-heavy. In this article we study the possibility that the dark matter is even heavier than the inflaton, its existence follows from the inflaton dynamics, and its abundance today is {\it naturally} determined by the weakness of gravitational interaction. This implies that the super-heavy dark matter scenarios can be tested via the measurements of inflationary parameters and/or the CMB isocurvature perturbations and non-Gaussianities. We explicitly work out details of three Coleman-Weinberg inflation scenarios, study the systematics of super-heavy dark matter production in those cases, and compute which parts of the parameter spaces can be probed by the future CMB measurements.
2206.05965
Zhan Sun
Xuan Luo, Ying-Zhao Jiang, Gui-Yuan Zhang, and Zhan Sun
Doubly-charmed baryon production in $Z$ boson decay
v1: 14pages, 2 figures, and 1 table; v2: references added
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we carry out a detailed study of doubly-charmed baryon production in $Z$ boson decay, on the basis of the nonrelativistic QCD factorization. With the inclusion of the di-quark states $(cc)[^3S_1]_{\bar{\textbf{3}}}$ and $(cc)[^1S_0]_{{\textbf{6}}}$, the branching ratio of $\mathcal{B}_{Z \to \Xi_{cc}+X}$ is predicted to be of the $10^{-5}$ order, indicating its experimental measurability. By comparing to the $\Lambda^{+}_{c}$ yield in $Z$ decay, we predict $\mathcal{R}_{\Xi_{cc}^{+}}(=\frac{\Gamma(Z \to \Xi^{+}_{cc}) \times \mathcal{B}(\Xi^{+}_{cc} \to \Lambda_c^{+}K^{-}\pi^{+})}{\Gamma(Z \to \Lambda_c^{+})})=(0.85^{+0.10}_{-0.07}) \times 10^{-4}$ and $\mathcal{R}_{\Xi_{cc}^{++}}(=\frac{\Gamma(Z \to \Xi^{++}_{cc}) \times \mathcal{B}(\Xi^{++}_{cc} \to \Lambda_c^{+}K^{-}\pi^{+}\pi^{+})}{\Gamma(Z \to \Lambda_c^{+})})=(1.70^{+0.20}_{-0.14}) \times 10^{-4}$, which are at clear variance with the SELEX measurements but comparable with the values given by the LHCb and Belle collaborations.
[ { "created": "Mon, 13 Jun 2022 08:25:38 GMT", "version": "v1" }, { "created": "Tue, 14 Jun 2022 12:16:35 GMT", "version": "v2" } ]
2022-06-15
[ [ "Luo", "Xuan", "" ], [ "Jiang", "Ying-Zhao", "" ], [ "Zhang", "Gui-Yuan", "" ], [ "Sun", "Zhan", "" ] ]
In this paper, we carry out a detailed study of doubly-charmed baryon production in $Z$ boson decay, on the basis of the nonrelativistic QCD factorization. With the inclusion of the di-quark states $(cc)[^3S_1]_{\bar{\textbf{3}}}$ and $(cc)[^1S_0]_{{\textbf{6}}}$, the branching ratio of $\mathcal{B}_{Z \to \Xi_{cc}+X}$ is predicted to be of the $10^{-5}$ order, indicating its experimental measurability. By comparing to the $\Lambda^{+}_{c}$ yield in $Z$ decay, we predict $\mathcal{R}_{\Xi_{cc}^{+}}(=\frac{\Gamma(Z \to \Xi^{+}_{cc}) \times \mathcal{B}(\Xi^{+}_{cc} \to \Lambda_c^{+}K^{-}\pi^{+})}{\Gamma(Z \to \Lambda_c^{+})})=(0.85^{+0.10}_{-0.07}) \times 10^{-4}$ and $\mathcal{R}_{\Xi_{cc}^{++}}(=\frac{\Gamma(Z \to \Xi^{++}_{cc}) \times \mathcal{B}(\Xi^{++}_{cc} \to \Lambda_c^{+}K^{-}\pi^{+}\pi^{+})}{\Gamma(Z \to \Lambda_c^{+})})=(1.70^{+0.20}_{-0.14}) \times 10^{-4}$, which are at clear variance with the SELEX measurements but comparable with the values given by the LHCb and Belle collaborations.
1911.03370
Babak Salehi Kasmaei
Babak Salehi Kasmaei and Michael Strickland
Photon production and elliptic flow from momentum-anisotropic quark-gluon plasma
19 pages, 10 figures
Phys. Rev. D 102, 014037 (2020)
10.1103/PhysRevD.102.014037
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The emission of real photons from a momentum-anisotropic quark-gluon plasma (QGP) is affected by both the collective flow of the radiating medium and the modification of local rest frame emission rate due to the anisotropic momentum distribution of partonic degrees of freedom. In this paper, we first calculate the photon production rate from an ellipsoidally momentum-anisotropic QGP including hard contributions from Compton scattering and quark pair annihilation and soft contribution calculated using the hard thermal loop (HTL) approximation. We introduce a parametrization of the nonequilibrium rate in order to facilitate its further application in yield and flow calculations. We convolve the anisotropic photon rate with the space-time evolution of QGP provided by 3+1d anisotropic hydrodynamics (aHydro) to obtain the yield and the elliptic flow coefficient $v_2$ of photons from QGP generated at Pb-Pb collisions at LHC at 2.76 TeV and Au-Au collisions at RHIC at 200 GeV. We investigate the effects of various parameters on the results. In particular we analyze the sensitivity of results to initial momentum anisotropy.
[ { "created": "Fri, 8 Nov 2019 16:51:05 GMT", "version": "v1" } ]
2020-07-29
[ [ "Kasmaei", "Babak Salehi", "" ], [ "Strickland", "Michael", "" ] ]
The emission of real photons from a momentum-anisotropic quark-gluon plasma (QGP) is affected by both the collective flow of the radiating medium and the modification of local rest frame emission rate due to the anisotropic momentum distribution of partonic degrees of freedom. In this paper, we first calculate the photon production rate from an ellipsoidally momentum-anisotropic QGP including hard contributions from Compton scattering and quark pair annihilation and soft contribution calculated using the hard thermal loop (HTL) approximation. We introduce a parametrization of the nonequilibrium rate in order to facilitate its further application in yield and flow calculations. We convolve the anisotropic photon rate with the space-time evolution of QGP provided by 3+1d anisotropic hydrodynamics (aHydro) to obtain the yield and the elliptic flow coefficient $v_2$ of photons from QGP generated at Pb-Pb collisions at LHC at 2.76 TeV and Au-Au collisions at RHIC at 200 GeV. We investigate the effects of various parameters on the results. In particular we analyze the sensitivity of results to initial momentum anisotropy.
1207.6390
Bhubanjyoti Bhattacharya
Bhubanjyoti Bhattacharya, Michael Gronau, Jonathan L. Rosner
Nonleptonic Charm Decays and CP Violation
16 pages, 5 figures, to appear in the proceedings of The 5th International Workshop on Charm Physics (Charm 2012), 14-17 May 2012, Honolulu, Hawai'i 96822
null
null
UdeM-GPP-TH-12-211; EFI 12-19; TECHNION-PH-12-11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we briefly present a flavor-SU(3) technique to study branching ratios and direct CP asymmetries $D$-meson decays. The first part of the talk is meant to set up a foundation, based on previous work, to deal with flavor-SU(3) amplitudes and relative strong phases. In addition, we present a model for dealing with SU(3)-breaking in branching ratio measurements of SCS $D^0$ decays. In the second part of the talk we make use of a proposal for an enhanced CP-violating penguin in the SM, to explain the recent LHCb and CDF observations of CP violation in SCS $D^0$ decays. Furthermore, we use our model to predict CP violation in $\pi^0\pi^0$ and $K^+\bar{K}^0$ final states. Large experimental bounds on individual CP asymmetries give rise to a large allowed range of $\delta$, the strong phase of the CP-violating penguin. We also briefly discuss future prospects.
[ { "created": "Thu, 26 Jul 2012 19:55:33 GMT", "version": "v1" }, { "created": "Sun, 5 Aug 2012 23:24:24 GMT", "version": "v2" } ]
2012-08-07
[ [ "Bhattacharya", "Bhubanjyoti", "" ], [ "Gronau", "Michael", "" ], [ "Rosner", "Jonathan L.", "" ] ]
In this talk we briefly present a flavor-SU(3) technique to study branching ratios and direct CP asymmetries $D$-meson decays. The first part of the talk is meant to set up a foundation, based on previous work, to deal with flavor-SU(3) amplitudes and relative strong phases. In addition, we present a model for dealing with SU(3)-breaking in branching ratio measurements of SCS $D^0$ decays. In the second part of the talk we make use of a proposal for an enhanced CP-violating penguin in the SM, to explain the recent LHCb and CDF observations of CP violation in SCS $D^0$ decays. Furthermore, we use our model to predict CP violation in $\pi^0\pi^0$ and $K^+\bar{K}^0$ final states. Large experimental bounds on individual CP asymmetries give rise to a large allowed range of $\delta$, the strong phase of the CP-violating penguin. We also briefly discuss future prospects.
hep-ph/9501257
Yong Yeon Keum
M. Gourdin, Y. Y. Keum and X. Y. Pham
Factorization and SU(2) Heavy Flavor Symmetry for B-Meson Decays Producing Charmonium
35 pages ( Latex ) with 10 figures (available by request)
Phys.Rev. D52 (1995) 1597-1613
10.1103/PhysRevD.52.1597
PAR/LPTHE/95-01
hep-ph
null
We show that the factorization assumption in color-suppressed $B$ meson decays is not ruled out by experimental data on $B \ra K(K^*) + J/\Psi(\Psi^{'})$. The problem previously pointed out might be due to an inadequate choice of hadronic form factors. Within the Isgur-Wise SU(2) heavy flavor symmetry framework, we search for possible $q^2$ dependence of form factors that are capable of explaining simultaneously the large longitudinal polarization $\rho_L$ observed in $B \ra K^* + J/\Psi$ and the relatively small ratio of rates $R_{J/\Psi} = \Gamma(B \ra K^* + J/\Psi)/\Gamma(B \ra K + J/\Psi)$. We find out that the puzzle could be essentially understood if the $A_1(q^2)$ form factor is frankly decreasing, instead of being almost constant or increasing as commonly assumed. Of course, the possibility of understanding experimental data is not necessarily a proof of factorization.
[ { "created": "Tue, 10 Jan 1995 16:32:44 GMT", "version": "v1" } ]
2016-09-01
[ [ "Gourdin", "M.", "" ], [ "Keum", "Y. Y.", "" ], [ "Pham", "X. Y.", "" ] ]
We show that the factorization assumption in color-suppressed $B$ meson decays is not ruled out by experimental data on $B \ra K(K^*) + J/\Psi(\Psi^{'})$. The problem previously pointed out might be due to an inadequate choice of hadronic form factors. Within the Isgur-Wise SU(2) heavy flavor symmetry framework, we search for possible $q^2$ dependence of form factors that are capable of explaining simultaneously the large longitudinal polarization $\rho_L$ observed in $B \ra K^* + J/\Psi$ and the relatively small ratio of rates $R_{J/\Psi} = \Gamma(B \ra K^* + J/\Psi)/\Gamma(B \ra K + J/\Psi)$. We find out that the puzzle could be essentially understood if the $A_1(q^2)$ form factor is frankly decreasing, instead of being almost constant or increasing as commonly assumed. Of course, the possibility of understanding experimental data is not necessarily a proof of factorization.
2204.04805
Lingfeng Li
JiJi Fan, Lingfeng Li, Tao Liu, Kun-Feng Lyu
$W$-Boson Mass, Electroweak Precision Tests and SMEFT
8 pages, 3 figures, version accepted by PRD for publication
null
10.1103/PhysRevD.106.073010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently the CDF collaboration at the Tevatron reported a significant discrepancy between the direct measurement of the $W$-boson mass and its Standard Model (SM) prediction based on electroweak precision tests (EWPTs). In this paper we explore the potential origin of this discrepancy from physics beyond the SM. Explicitly, we work on a set of six-dimensional operators in the SM effective field theory (SMEFT) which are relevant to the EWPTs. By fitting to the data, we demonstrate that an upward shift in $m_W$ is driven by the operator $\mathcal{O}_{T}=\frac{1}{2}(H^{\dagger}\overset{\text{$\leftrightarrow$}}{D}_{\mu}H)^2$ with a coefficient $c_T ({\rm TeV}/\Lambda)^2 \gtrsim 0.01$. This suggests that the new physics scale favored by the CDF data should be multiple TeV for tree-level effects and sub TeV for loop-level effects. One simple example is to introduce a hypercharge-free electroweak triplet scalar which can raise the $c_T$ value at tree level. We also study the potential to further test the relevant SMEFT by measuring Higgs-coupling, $m_W$ and other EWPTs at future circular $e^-e^+$ colliders.
[ { "created": "Mon, 11 Apr 2022 00:31:30 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2022 21:57:41 GMT", "version": "v2" } ]
2022-11-09
[ [ "Fan", "JiJi", "" ], [ "Li", "Lingfeng", "" ], [ "Liu", "Tao", "" ], [ "Lyu", "Kun-Feng", "" ] ]
Recently the CDF collaboration at the Tevatron reported a significant discrepancy between the direct measurement of the $W$-boson mass and its Standard Model (SM) prediction based on electroweak precision tests (EWPTs). In this paper we explore the potential origin of this discrepancy from physics beyond the SM. Explicitly, we work on a set of six-dimensional operators in the SM effective field theory (SMEFT) which are relevant to the EWPTs. By fitting to the data, we demonstrate that an upward shift in $m_W$ is driven by the operator $\mathcal{O}_{T}=\frac{1}{2}(H^{\dagger}\overset{\text{$\leftrightarrow$}}{D}_{\mu}H)^2$ with a coefficient $c_T ({\rm TeV}/\Lambda)^2 \gtrsim 0.01$. This suggests that the new physics scale favored by the CDF data should be multiple TeV for tree-level effects and sub TeV for loop-level effects. One simple example is to introduce a hypercharge-free electroweak triplet scalar which can raise the $c_T$ value at tree level. We also study the potential to further test the relevant SMEFT by measuring Higgs-coupling, $m_W$ and other EWPTs at future circular $e^-e^+$ colliders.
1710.02719
Dmitri Melikhov
Dmitri Melikhov, Anastasiia Kozachuk, Nikolai Nikitin
Rare FCNC radiative leptonic decays $B\to\gamma\ell^+\ell^-$
6 pages, talk given at "The European Physical Society Conference on High Energy Physics - EPS-HEP 2017" (5 - 12 July 2017, Venice, Italy)
PoS (EPS-HEP2017) 228
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present our recent results for long-distance QCD effects in the FCNC radiative leptonic decays $B\to\gamma\ell^+\ell^-$, $\ell=\{e,\mu\}$. One encounters here two distinct types of long-distance effects: those encoded in the $B\to\gamma$ transition form factors induced by the $b\to q$ quark currents, and those related to the charm-loop effects. We calculate the $B\to\gamma$ form factors in a broad range of the momentum transfers making use of the relativisitc dispersion approach based on the constituent quark picture which has proven to provide reliable predictions for many weak-transition form factors. Concerning the description of the charm-loop contributions, we point out two observations: First, the precise description of the charmonium resonances, in particular, the relative phases between $\psi$ and $\psi'$, has impact on the differential distributions and on the forward-backward asymmetry, $A_{\rm FB}$, in a broad range of $q^2\ge 5$ GeV$^2$. Second, the shape of $A_{\rm FB}$ in $B\to\gamma\ell^+\ell^-$ and in $B\to V\ell^+\ell^-$ ($V$ the vector meson) {\it in the $q^2$-region between $\psi$ and $\psi'$} provides an unambiguous probe of the relative phases between $\psi$ and $\psi'$. Fixing the latter will lead to a strong reduction of the theoretical uncertainties in $A_{\rm FB}$ at $q^2=5-9$ GeV$^2$ where it has the sensitivity to physics beyond the SM.
[ { "created": "Sat, 7 Oct 2017 18:46:59 GMT", "version": "v1" } ]
2017-10-10
[ [ "Melikhov", "Dmitri", "" ], [ "Kozachuk", "Anastasiia", "" ], [ "Nikitin", "Nikolai", "" ] ]
We present our recent results for long-distance QCD effects in the FCNC radiative leptonic decays $B\to\gamma\ell^+\ell^-$, $\ell=\{e,\mu\}$. One encounters here two distinct types of long-distance effects: those encoded in the $B\to\gamma$ transition form factors induced by the $b\to q$ quark currents, and those related to the charm-loop effects. We calculate the $B\to\gamma$ form factors in a broad range of the momentum transfers making use of the relativisitc dispersion approach based on the constituent quark picture which has proven to provide reliable predictions for many weak-transition form factors. Concerning the description of the charm-loop contributions, we point out two observations: First, the precise description of the charmonium resonances, in particular, the relative phases between $\psi$ and $\psi'$, has impact on the differential distributions and on the forward-backward asymmetry, $A_{\rm FB}$, in a broad range of $q^2\ge 5$ GeV$^2$. Second, the shape of $A_{\rm FB}$ in $B\to\gamma\ell^+\ell^-$ and in $B\to V\ell^+\ell^-$ ($V$ the vector meson) {\it in the $q^2$-region between $\psi$ and $\psi'$} provides an unambiguous probe of the relative phases between $\psi$ and $\psi'$. Fixing the latter will lead to a strong reduction of the theoretical uncertainties in $A_{\rm FB}$ at $q^2=5-9$ GeV$^2$ where it has the sensitivity to physics beyond the SM.
1511.06039
Simone Marzani
Simone Marzani
Combining $Q_T$ and small-$x$ resummations
Corrected a mistake in Eq.(40)
Phys. Rev. D 93, 054047 (2016)
10.1103/PhysRevD.93.054047
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze transverse momentum ($Q_T$) resummation of a colorless final state, e.g. Higgs production in gluon fusion or the production of a lepton pair via the Drell-Yan mechanism, in the limit where the invariant mass of the final state is much less then the center-of-mass energy, i.e. $Q^2\ll s$. We show how the traditional resummation of logarithms of $Q_T/Q$ can be supplemented with the resummation of the leading logarithmic contributions at small $x=Q^2/s$ and we compute the necessary ingredients to perform such joint resummation.
[ { "created": "Thu, 19 Nov 2015 01:28:05 GMT", "version": "v1" }, { "created": "Thu, 24 Mar 2016 16:37:13 GMT", "version": "v2" }, { "created": "Sat, 12 Nov 2016 15:42:23 GMT", "version": "v3" }, { "created": "Fri, 11 Dec 2020 09:56:27 GMT", "version": "v4" } ]
2020-12-14
[ [ "Marzani", "Simone", "" ] ]
We analyze transverse momentum ($Q_T$) resummation of a colorless final state, e.g. Higgs production in gluon fusion or the production of a lepton pair via the Drell-Yan mechanism, in the limit where the invariant mass of the final state is much less then the center-of-mass energy, i.e. $Q^2\ll s$. We show how the traditional resummation of logarithms of $Q_T/Q$ can be supplemented with the resummation of the leading logarithmic contributions at small $x=Q^2/s$ and we compute the necessary ingredients to perform such joint resummation.
hep-ph/9407232
Dietrich Lehner
D. Lehner
Initial State Radiation to Off-shell $\Z^0$ Pair Production in $e^+e^-$ Annihilation
6 pages (LaTeX), 2 figures (not included, a uuencoded file containing the LaTeX and all postscript files is available via anonymous ftp from convex.ifh.de as /pub/preprint/desy94-105.uu), DESY 94-105
Mod. Phys. Lett. A9 (1994) 2937
10.1142/S021773239400277X
null
hep-ph
null
A study of the Standard Model reaction $\e^+e^- \rightarrow (\Z^0\Z^0) \rightarrow f_1\bar{f_1}f_2\bar{f_2}$ including the effects of the finite $\Z^0$~width and initial state radiative corrections is presented. All angular phase space integrations are performed analytically. The remaining invariant masses are integrated numerically. Semi-analytical and numerical results in the energy range $\RS=200\;GeV$ to $1\;TeV$ are reported.
[ { "created": "Tue, 5 Jul 1994 19:26:21 GMT", "version": "v1" } ]
2015-06-25
[ [ "Lehner", "D.", "" ] ]
A study of the Standard Model reaction $\e^+e^- \rightarrow (\Z^0\Z^0) \rightarrow f_1\bar{f_1}f_2\bar{f_2}$ including the effects of the finite $\Z^0$~width and initial state radiative corrections is presented. All angular phase space integrations are performed analytically. The remaining invariant masses are integrated numerically. Semi-analytical and numerical results in the energy range $\RS=200\;GeV$ to $1\;TeV$ are reported.