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hep-ph/9608489
Jorge L. Lopez
D. Nanopoulos
Theoretical Summary
21 pages, LaTeX (uses sprocl.sty)
null
null
CTP-TAMU-43/96
hep-ph
null
After a quick tour through the present status of the Standard Model, an attempt is made to set up a framework to discuss some presently available exotica, including $R_b$ and the CDF $ee\gamma\gamma+E_T\hskip-13pt/\ $ ``event." Supersymmetry seems to be a key player in establishing a paradigm shift beyond the Standard Model. (XI Topical Workshop on Proton-antiproton Collider Physics, Abano Terme (Padua), Italy, 26 May-1 June, 1996.)
[ { "created": "Thu, 29 Aug 1996 15:58:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nanopoulos", "D.", "" ] ]
After a quick tour through the present status of the Standard Model, an attempt is made to set up a framework to discuss some presently available exotica, including $R_b$ and the CDF $ee\gamma\gamma+E_T\hskip-13pt/\ $ ``event." Supersymmetry seems to be a key player in establishing a paradigm shift beyond the Standard Model. (XI Topical Workshop on Proton-antiproton Collider Physics, Abano Terme (Padua), Italy, 26 May-1 June, 1996.)
2109.05678
Shi-Yuan Li
Yi Jin, Shi-Yuan Li, Yan-Rui Liu, Qin Qin, Zong-Guo Si, and Fu-Sheng Yu
Colour and baryon number fluctuation of preconfinement system in production process and T_cc structure
20 papges, 6 figs
null
10.1103/PhysRevD.104.114009
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We suggest to study the production mechanism and some details of the production properties to probe the structure of the DDpi resonance T_cc^+ recently observed by the LHCb Collaboration. If the resonance is produced as a four-quark state, one can find the corresponding finger prints via measurements on some production properties that are the same as those of Xi_cc. The reason is that a special colour connection on the interface between the perturbative and non perturbative QCD is required for these doubly-charm hadron production. On the other hand, if T_cc^+ is produced as a hadron molecule, the measurement on the momentum correlation of DD^* can be a smoking gun to make the judgement. The present data favour a compact four-quark state production via the cc diquark fragmentation.
[ { "created": "Mon, 13 Sep 2021 03:05:21 GMT", "version": "v1" } ]
2021-12-22
[ [ "Jin", "Yi", "" ], [ "Li", "Shi-Yuan", "" ], [ "Liu", "Yan-Rui", "" ], [ "Qin", "Qin", "" ], [ "Si", "Zong-Guo", "" ], [ "Yu", "Fu-Sheng", "" ] ]
We suggest to study the production mechanism and some details of the production properties to probe the structure of the DDpi resonance T_cc^+ recently observed by the LHCb Collaboration. If the resonance is produced as a four-quark state, one can find the corresponding finger prints via measurements on some production properties that are the same as those of Xi_cc. The reason is that a special colour connection on the interface between the perturbative and non perturbative QCD is required for these doubly-charm hadron production. On the other hand, if T_cc^+ is produced as a hadron molecule, the measurement on the momentum correlation of DD^* can be a smoking gun to make the judgement. The present data favour a compact four-quark state production via the cc diquark fragmentation.
1011.1759
Richard Corke
Richard Corke, Torbj\"orn Sj\"ostrand
Interleaved Parton Showers and Tuning Prospects
null
JHEP 1103:032,2011
10.1007/JHEP03(2011)032
LU TP 10-26, MCnet/10/20
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
General-purpose Monte Carlo event generators have become important tools in particle physics, allowing the simulation of exclusive hadronic final states. In this article we examine the Pythia 8 generator, in particular focusing on its parton-shower algorithms. Some relevant new additions to the code are introduced, that should allow for a better description of data. We also implement and compare with 2 to 3 real-emission QCD matrix elements, to check how well the shower algorithm fills the phase space away from the soft and collinear regions. A tuning of the generator to Tevatron data is performed for two PDF sets and the impact of first new LHC data is examined.
[ { "created": "Mon, 8 Nov 2010 10:36:43 GMT", "version": "v1" } ]
2011-03-18
[ [ "Corke", "Richard", "" ], [ "Sjöstrand", "Torbjörn", "" ] ]
General-purpose Monte Carlo event generators have become important tools in particle physics, allowing the simulation of exclusive hadronic final states. In this article we examine the Pythia 8 generator, in particular focusing on its parton-shower algorithms. Some relevant new additions to the code are introduced, that should allow for a better description of data. We also implement and compare with 2 to 3 real-emission QCD matrix elements, to check how well the shower algorithm fills the phase space away from the soft and collinear regions. A tuning of the generator to Tevatron data is performed for two PDF sets and the impact of first new LHC data is examined.
2209.08257
Yasutaka Takanishi
Kento Asai, Yuhei Sakai, Joe Sato, Yasutaka Takanishi, Masato Yamanaka
Asymmetric Mediator in Scotogenic Model
17 pages, 1 table, 5 figures
null
10.1016/j.physletb.2022.137627
STUPP-22-258
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scotogenic model is the Standard Model (SM) with Z_2 symmetry and the addition of Z_2 odd right-handed Majorana neutrinos and SU(2)_L doublet scalar fields. We have extended the original scotogenic model by an additional Z_2 odd singlet scalar field that plays a role in dark matter. In our model, the asymmetries of the lepton and Z_2 odd doublet scalar are simultaneously produced through CP-violating right-handed neutrino decays. While the former is converted into baryon asymmetry through the sphaleron process, the latter is relaid to the DM density through the decay of SU(2)_L doublet scalar that is named "asymmetric mediator". In this way, we provide an extended scotogenic model that predicts the energy densities of baryon and dark matter being in the same order of magnitude, and also explains the low-energy neutrino masses and mixing angles.
[ { "created": "Sat, 17 Sep 2022 05:30:14 GMT", "version": "v1" } ]
2022-12-21
[ [ "Asai", "Kento", "" ], [ "Sakai", "Yuhei", "" ], [ "Sato", "Joe", "" ], [ "Takanishi", "Yasutaka", "" ], [ "Yamanaka", "Masato", "" ] ]
The scotogenic model is the Standard Model (SM) with Z_2 symmetry and the addition of Z_2 odd right-handed Majorana neutrinos and SU(2)_L doublet scalar fields. We have extended the original scotogenic model by an additional Z_2 odd singlet scalar field that plays a role in dark matter. In our model, the asymmetries of the lepton and Z_2 odd doublet scalar are simultaneously produced through CP-violating right-handed neutrino decays. While the former is converted into baryon asymmetry through the sphaleron process, the latter is relaid to the DM density through the decay of SU(2)_L doublet scalar that is named "asymmetric mediator". In this way, we provide an extended scotogenic model that predicts the energy densities of baryon and dark matter being in the same order of magnitude, and also explains the low-energy neutrino masses and mixing angles.
1504.07263
Pedro Schwaller
Pedro Schwaller
Gravitational Waves From a Dark (Twin) Phase Transition
12 pages, 3 figures. v2: Added references, Fig. 3 improved
Phys. Rev. Lett. 115, 181101 (2015)
10.1103/PhysRevLett.115.181101
CERN-PH-TH-2015-093
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we show that a large class of models with a composite dark sector undergo a strong first order phase transition in the early universe, which could lead to a detectable gravitational wave signal. We summarise the basic conditions for a strong first order phase transition for SU(N) dark sectors with n_f flavours, calculate the gravitational wave spectrum and show that, depending on the dark confinement scale, it can be detected at eLISA or in pulsar timing array experiments. The gravitational wave signal provides a unique test of the gravitational interactions of a dark sector, and we discuss the complementarity with conventional searches for new dark sectors. The discussion includes Twin Higgs and SIMP models as well as symmetric and asymmetric composite dark matter scenarios.
[ { "created": "Mon, 27 Apr 2015 20:10:28 GMT", "version": "v1" }, { "created": "Mon, 18 May 2015 14:24:57 GMT", "version": "v2" } ]
2015-11-04
[ [ "Schwaller", "Pedro", "" ] ]
In this work, we show that a large class of models with a composite dark sector undergo a strong first order phase transition in the early universe, which could lead to a detectable gravitational wave signal. We summarise the basic conditions for a strong first order phase transition for SU(N) dark sectors with n_f flavours, calculate the gravitational wave spectrum and show that, depending on the dark confinement scale, it can be detected at eLISA or in pulsar timing array experiments. The gravitational wave signal provides a unique test of the gravitational interactions of a dark sector, and we discuss the complementarity with conventional searches for new dark sectors. The discussion includes Twin Higgs and SIMP models as well as symmetric and asymmetric composite dark matter scenarios.
2301.07728
Christopher Cappiello
Christopher Cappiello
An Analytic Approach to Light Dark Matter Propagation
5 pages, 4 figures. Text and figures updated to match the PRL version
null
10.1103/PhysRevLett.130.221001
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If dark matter interacts too strongly with nuclei, it could be slowed to undetectable speeds in Earth's crust or atmosphere before ever reaching a detector. For sub-GeV dark matter, analytic approximations appropriate for heavier dark matter fail, necessitating the use of computationally expensive simulations. We present a new method of modeling attenuation of light dark matter in the Earth, based on the approximation that the scattering is isotropic in the lab frame. We show that this approach agrees well with Monte Carlo results, and can be much faster when the number of scatterings becomes large, as the runtime for Monte Carlo methods increases exponentially with cross section. We use this method to model attenuation for sub-dominant dark matter--that is, particles that make up a small fraction of the dark matter density--and show that previous work on sub-dominant dark matter overestimates the sensitivity of direct detection experiments.
[ { "created": "Wed, 18 Jan 2023 19:00:13 GMT", "version": "v1" }, { "created": "Mon, 28 Aug 2023 22:07:12 GMT", "version": "v2" } ]
2023-08-30
[ [ "Cappiello", "Christopher", "" ] ]
If dark matter interacts too strongly with nuclei, it could be slowed to undetectable speeds in Earth's crust or atmosphere before ever reaching a detector. For sub-GeV dark matter, analytic approximations appropriate for heavier dark matter fail, necessitating the use of computationally expensive simulations. We present a new method of modeling attenuation of light dark matter in the Earth, based on the approximation that the scattering is isotropic in the lab frame. We show that this approach agrees well with Monte Carlo results, and can be much faster when the number of scatterings becomes large, as the runtime for Monte Carlo methods increases exponentially with cross section. We use this method to model attenuation for sub-dominant dark matter--that is, particles that make up a small fraction of the dark matter density--and show that previous work on sub-dominant dark matter overestimates the sensitivity of direct detection experiments.
1703.07642
Edward Hardy
Edward Hardy, James Unwin
Symmetric and Asymmetric Reheating
JHEP version
null
10.1007/JHEP09(2017)113
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study models in which the inflaton is coupled to two otherwise decoupled sectors, and the effect of preheating and related processes on their energy densities during the evolution of the universe. Over most of parameter space, preheating is not disrupted by the presence of extra sectors, and even comparatively weakly coupled sectors can get an order 1 fraction of the total energy at this time. If two sectors are both preheated, the high number densities could also lead to inflaton mediated thermalisation. If only one sector is preheated, Bose enhancement of the late time inflaton decays may cause significant deviations from the perturbative prediction for their relative reheat temperatures. Meanwhile, in Non-Oscillatory inflation models resonant effects can result in exponentially large final temperature differences between sectors that have similar couplings to the inflaton. Asymmetric reheating is potentially relevant for a range of beyond the Standard Model physics scenarios. We show that in dark matter freeze-in models, hidden sector temperatures a factor of 10 below that of the visible sector are typically needed for the relic abundance to be set solely by freeze-in dynamics.
[ { "created": "Wed, 22 Mar 2017 13:35:08 GMT", "version": "v1" }, { "created": "Wed, 29 Mar 2017 07:33:05 GMT", "version": "v2" }, { "created": "Sun, 1 Oct 2017 09:02:35 GMT", "version": "v3" } ]
2017-10-25
[ [ "Hardy", "Edward", "" ], [ "Unwin", "James", "" ] ]
We study models in which the inflaton is coupled to two otherwise decoupled sectors, and the effect of preheating and related processes on their energy densities during the evolution of the universe. Over most of parameter space, preheating is not disrupted by the presence of extra sectors, and even comparatively weakly coupled sectors can get an order 1 fraction of the total energy at this time. If two sectors are both preheated, the high number densities could also lead to inflaton mediated thermalisation. If only one sector is preheated, Bose enhancement of the late time inflaton decays may cause significant deviations from the perturbative prediction for their relative reheat temperatures. Meanwhile, in Non-Oscillatory inflation models resonant effects can result in exponentially large final temperature differences between sectors that have similar couplings to the inflaton. Asymmetric reheating is potentially relevant for a range of beyond the Standard Model physics scenarios. We show that in dark matter freeze-in models, hidden sector temperatures a factor of 10 below that of the visible sector are typically needed for the relic abundance to be set solely by freeze-in dynamics.
hep-ph/0009186
Werner Porod
W. Porod
Reconstruction of Supersymmetric Theories at High Energy Scales
LaTex, 3 pages, 3 Figures included, contribution to ICHEP2000, needs ws-p10x7.cls (included)
null
null
IFIC/00-55
hep-ph
null
We have studied the reconstruction of supersymmetric theories at high scales by evolving the fundamental parameters from the electroweak scale upwards. Universal minimal supergravity and gauge mediated supersymmetry breaking have been taken as representative alternatives. Pseudo-fixed point structures require the low-energy boundary values to be measured with high precision.
[ { "created": "Fri, 15 Sep 2000 09:37:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Porod", "W.", "" ] ]
We have studied the reconstruction of supersymmetric theories at high scales by evolving the fundamental parameters from the electroweak scale upwards. Universal minimal supergravity and gauge mediated supersymmetry breaking have been taken as representative alternatives. Pseudo-fixed point structures require the low-energy boundary values to be measured with high precision.
hep-ph/0309167
Jisuke Kubo
Jisuke Kubo
Majorana Phase in Minimal S_3 Invariant Extension of the Standard Model
11 pages, LaTeX, 4 figures, errors corrected
Phys.Lett. B578 (2004) 156-164; Erratum-ibid. B619 (2005) 387-388
10.1016/j.physletb.2005.06.013
MPP-2003-77
hep-ph
null
The leptonic sector in a recently proposed minimal extension of the standard model, in which the permutation symmetry S_3 is assumed to be an exact flavor symmetry at the weak scale, is revisited. We find that S_3 with an additional Z_{N} symmetry allows CP violating phases in the neutrino mixing. The leptonic sector contains six real parameters with two independent phases to describe charged lepton and neutrino masses and the neutrino mixing. The model predicts: an inverted spectrum of neutrino mass, tan theta_{23}=1+O(m_e^2/m_mu^2) and sin theta_{13}=m_e/sqrt{2}m_mu+O(m_em_mu/m_{tau}^2) simeq 0.0034. Neutrino mass as well as the effective Majorana mass <m_{ee}> in the neutrinoless double-beta decay can be expressed in a closed form as a function of phi_nu, Delta m^2_{21},Delta m^2_{23} and tantheta_{12}, where phi_nu is one of the independent phases. The model also predicts <m_{ee}> geq (0.036 - 0.066) eV.
[ { "created": "Mon, 15 Sep 2003 14:46:09 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 2003 12:07:56 GMT", "version": "v2" }, { "created": "Mon, 13 Jun 2005 02:34:04 GMT", "version": "v3" } ]
2015-06-25
[ [ "Kubo", "Jisuke", "" ] ]
The leptonic sector in a recently proposed minimal extension of the standard model, in which the permutation symmetry S_3 is assumed to be an exact flavor symmetry at the weak scale, is revisited. We find that S_3 with an additional Z_{N} symmetry allows CP violating phases in the neutrino mixing. The leptonic sector contains six real parameters with two independent phases to describe charged lepton and neutrino masses and the neutrino mixing. The model predicts: an inverted spectrum of neutrino mass, tan theta_{23}=1+O(m_e^2/m_mu^2) and sin theta_{13}=m_e/sqrt{2}m_mu+O(m_em_mu/m_{tau}^2) simeq 0.0034. Neutrino mass as well as the effective Majorana mass <m_{ee}> in the neutrinoless double-beta decay can be expressed in a closed form as a function of phi_nu, Delta m^2_{21},Delta m^2_{23} and tantheta_{12}, where phi_nu is one of the independent phases. The model also predicts <m_{ee}> geq (0.036 - 0.066) eV.
hep-ph/9811406
Marek Nowakowski
Albert Bramon and Marek Nowakowski
Bell-inequalities for Entangled Neutral Kaons
8 pages, Latex
Phys.Rev.Lett. 83 (1999) 1-5
10.1103/PhysRevLett.83.1
null
hep-ph quant-ph
null
We extend the use of Bell-inequalities to $\Phi \to K^0 \bar{K^0}$ decays by exploiting analogies and differences to the well-known and experimentally verified singlet-spin case. Contrasting with other analyses, our Bell-inequalities are violated by quantum mechanics and can strictly be derived from local realistic theories. In principle, quantum mechanics could then be tested using unstable, oscillating states governed by a CP-violating Hamiltonian.
[ { "created": "Thu, 19 Nov 1998 16:51:09 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bramon", "Albert", "" ], [ "Nowakowski", "Marek", "" ] ]
We extend the use of Bell-inequalities to $\Phi \to K^0 \bar{K^0}$ decays by exploiting analogies and differences to the well-known and experimentally verified singlet-spin case. Contrasting with other analyses, our Bell-inequalities are violated by quantum mechanics and can strictly be derived from local realistic theories. In principle, quantum mechanics could then be tested using unstable, oscillating states governed by a CP-violating Hamiltonian.
2201.12188
Matteo Becchetti
Simon Badger, Matteo Becchetti, Ekta Chaubey, Robin Marzucca, Francesco Sarandrea
One-loop QCD helicity amplitudes for $pp\to t\bar{t} j$ to $O(\epsilon^2)$
37 pages. ancillary files containing analytic amplitudes and integral evaluation routines. v2 references added. v3 fixing minor typos in the text and in the ancillary files
null
10.1007/JHEP06(2022)066
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute helicity amplitudes for the one-loop QCD corrections to top-quark pair production analytically in terms of a set of uniformly transcendental master integrals. We provide corrections up to $O(\epsilon^2)$ in the dimensional regulator for the first time which are relevant at NNLO. Four independent pentagon integral topologies appear in the complete description of the colour structure for which we provide numerical solutions using canonical form differential equations and the method of generalised power series expansions. Analytic forms of the boundary values are obtained in all cases except one where we find a one-dimensional integral representation.
[ { "created": "Fri, 28 Jan 2022 15:39:53 GMT", "version": "v1" }, { "created": "Fri, 11 Feb 2022 19:27:10 GMT", "version": "v2" }, { "created": "Mon, 25 Apr 2022 09:23:44 GMT", "version": "v3" } ]
2022-06-29
[ [ "Badger", "Simon", "" ], [ "Becchetti", "Matteo", "" ], [ "Chaubey", "Ekta", "" ], [ "Marzucca", "Robin", "" ], [ "Sarandrea", "Francesco", "" ] ]
We compute helicity amplitudes for the one-loop QCD corrections to top-quark pair production analytically in terms of a set of uniformly transcendental master integrals. We provide corrections up to $O(\epsilon^2)$ in the dimensional regulator for the first time which are relevant at NNLO. Four independent pentagon integral topologies appear in the complete description of the colour structure for which we provide numerical solutions using canonical form differential equations and the method of generalised power series expansions. Analytic forms of the boundary values are obtained in all cases except one where we find a one-dimensional integral representation.
1206.6949
Yong Tang
Yong Tang
Implications of LHC Searches for Massive Graviton
17 pages, 10 figures; References added; Accepted version by JHEP
JHEP 1208 (2012) 078
10.1007/JHEP08(2012)078
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the latest LHC available results, we consider the generic constraints on massive graviton. Both dijet and dilepton resonance searches are used. The limits on parameter space can be applied to many models. As an illustration, we show the constraints for Randall-Sundrum (RS) model. Implications on massive graviton and the coupling strength are discussed. For $k/M_{pl}=0.1$, $M_G<2.2$ TeV region is excluded at 95% confidence level. We also present some interesting implications on the RS radion with respect to the 125 GeV excess at the LHC. For $k/M_{pl}=0.1$, $\Lambda_\phi<13.8$ TeV is excluded where $\Lambda_\phi$ is the scale to charactarize the interaction strengh of radion.
[ { "created": "Fri, 29 Jun 2012 06:34:01 GMT", "version": "v1" }, { "created": "Tue, 31 Jul 2012 01:37:09 GMT", "version": "v2" } ]
2012-08-21
[ [ "Tang", "Yong", "" ] ]
With the latest LHC available results, we consider the generic constraints on massive graviton. Both dijet and dilepton resonance searches are used. The limits on parameter space can be applied to many models. As an illustration, we show the constraints for Randall-Sundrum (RS) model. Implications on massive graviton and the coupling strength are discussed. For $k/M_{pl}=0.1$, $M_G<2.2$ TeV region is excluded at 95% confidence level. We also present some interesting implications on the RS radion with respect to the 125 GeV excess at the LHC. For $k/M_{pl}=0.1$, $\Lambda_\phi<13.8$ TeV is excluded where $\Lambda_\phi$ is the scale to charactarize the interaction strengh of radion.
hep-ph/0101057
Anatoli Efremov
A.V. Efremov (JINR, Dubna)
Old and new parton distribution and fragmentation functions
9 pages, latex, czjphys2.sty, 4 eps figures. Submitted at 35-th Rancontre de Moriond, March 2000 and at Praha-SPIN-2000, July 2000. To be published in Czechoslovak J. Phys. (Suppl) 51 (2001)
Czech.J.Phys.51:A97-A105,2001
10.1007/s10582-001-0011-y
null
hep-ph
null
A short review of problems with parton distribution functions in nucleons, non-polarized and polarized, is given. The main part is devoted to the transversity distribution its possible measurement and its first experimental probe via spin asymmetry in semi-inclusive DIS. It is argued that the proton transversity distribution could be successfully measured in future DIS experiments with {\it longitudinally} polarized target.
[ { "created": "Sun, 7 Jan 2001 17:43:18 GMT", "version": "v1" } ]
2009-11-07
[ [ "Efremov", "A. V.", "", "JINR, Dubna" ] ]
A short review of problems with parton distribution functions in nucleons, non-polarized and polarized, is given. The main part is devoted to the transversity distribution its possible measurement and its first experimental probe via spin asymmetry in semi-inclusive DIS. It is argued that the proton transversity distribution could be successfully measured in future DIS experiments with {\it longitudinally} polarized target.
1903.11889
Ivica Picek
Ivica Picek
BSM Matter providing Neutrino Masses and Gauge Unification
Based on a lecture at the workshop "On a safe road to quantum gravity with matter", Hvar - Croatia, 11-14 September 2018
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present several scenarios developed in Zagreb, in which TeV-scale particles belonging to non-trivial weak-isospin multiplets give rise to neutrino-mass mechanisms different from conventional type I, II and III seesaw models. Two dim 9 tree-level mechanisms, presented first, provide an appealing testability of their exotic TeV-scale particles at the LHC. These models are not genuine, since their particles also provide competing dim 5 loop contributions. The loop-models presented next are genuine, without competing tree-level contributions. Among them, the three-loop model involves high-order weak multiplets leading to Landau poles. The one-loop model with scalar triplet as the largest multiplet, in addition to good UV properties, provides the particle set promising for gauge coupling unification. Therefore, it served us as a starting point for a study of SU(5) embedding of additional particles leading to viable unification scenarios. To distinguish among them begs for additional principle which reigns over particle completion and eventual dark matter considerations.
[ { "created": "Thu, 28 Mar 2019 10:47:15 GMT", "version": "v1" } ]
2019-03-29
[ [ "Picek", "Ivica", "" ] ]
I present several scenarios developed in Zagreb, in which TeV-scale particles belonging to non-trivial weak-isospin multiplets give rise to neutrino-mass mechanisms different from conventional type I, II and III seesaw models. Two dim 9 tree-level mechanisms, presented first, provide an appealing testability of their exotic TeV-scale particles at the LHC. These models are not genuine, since their particles also provide competing dim 5 loop contributions. The loop-models presented next are genuine, without competing tree-level contributions. Among them, the three-loop model involves high-order weak multiplets leading to Landau poles. The one-loop model with scalar triplet as the largest multiplet, in addition to good UV properties, provides the particle set promising for gauge coupling unification. Therefore, it served us as a starting point for a study of SU(5) embedding of additional particles leading to viable unification scenarios. To distinguish among them begs for additional principle which reigns over particle completion and eventual dark matter considerations.
1110.4848
Edward K. G. Sarkisyan
John Ellis, Hans-Thomas Janka, Nikolaos E. Mavromatos, Alexander S. Sakharov and Edward K. G. Sarkisyan
Probing Lorentz Violation in Neutrino Propagation from a Core-Collapse Supernova
29 pages, 9 figures. A subsection added. The version to appear in Phys. Rev. D
null
10.1103/PhysRevD.85.045032
KCL-PH-TH/2011-14, LCTS/2011-06, CERN-PH-TH/2011-131
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supernova explosions provide the most sensitive probes of neutrino propagation, such as the possibility that neutrino velocities might be affected by the foamy structure of space-time thought to be generated by quantum-gravitational (QG) effects. Recent two-dimensional simulations of the neutrino emissions from core-collapse supernovae suggest that they might exhibit variations in time on the scale of a few milliseconds. We analyze simulations of such neutrino emissions using a wavelet technique, and consider the limits that might be set on a linear or quadratic violation of Lorentz invariance in the group velocities of neutrinos of different energies, v/c = [1 \pm (E/M_{nuLV1})] or [1 \pm (E/M_{\nuLV2})^2], if variations on such short time scales were to be observed, where the mass scales M_{nuLVi} might appear in models of quantum gravity. We find prospective sensitivities to M_{nuLV1} ~ 2 X 10^{13} GeV and M_{nuLV2} ~ 10^6 GeV at the 95% confidence level, up to two orders of magnitude beyond estimates made using previous one-dimensional simulations of core-collapse supernovae. We also analyze the prospective sensitivities to scenarios in which the propagation times of neutrinos of fixed energies are subject to stochastic fluctuations.
[ { "created": "Fri, 21 Oct 2011 17:24:28 GMT", "version": "v1" }, { "created": "Thu, 2 Feb 2012 17:23:09 GMT", "version": "v2" } ]
2015-05-30
[ [ "Ellis", "John", "" ], [ "Janka", "Hans-Thomas", "" ], [ "Mavromatos", "Nikolaos E.", "" ], [ "Sakharov", "Alexander S.", "" ], [ "Sarkisyan", "Edward K. G.", "" ] ]
Supernova explosions provide the most sensitive probes of neutrino propagation, such as the possibility that neutrino velocities might be affected by the foamy structure of space-time thought to be generated by quantum-gravitational (QG) effects. Recent two-dimensional simulations of the neutrino emissions from core-collapse supernovae suggest that they might exhibit variations in time on the scale of a few milliseconds. We analyze simulations of such neutrino emissions using a wavelet technique, and consider the limits that might be set on a linear or quadratic violation of Lorentz invariance in the group velocities of neutrinos of different energies, v/c = [1 \pm (E/M_{nuLV1})] or [1 \pm (E/M_{\nuLV2})^2], if variations on such short time scales were to be observed, where the mass scales M_{nuLVi} might appear in models of quantum gravity. We find prospective sensitivities to M_{nuLV1} ~ 2 X 10^{13} GeV and M_{nuLV2} ~ 10^6 GeV at the 95% confidence level, up to two orders of magnitude beyond estimates made using previous one-dimensional simulations of core-collapse supernovae. We also analyze the prospective sensitivities to scenarios in which the propagation times of neutrinos of fixed energies are subject to stochastic fluctuations.
1112.2604
Mauro Anselmino
Mauro Anselmino, Vincenzo Barone and Aram Kotzinian
A leading-twist beam-spin asymmetry in double-hadron inclusive lepto-production
4 pages, 1 figure
null
10.1016/j.physletb.2012.06.003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that a new beam-spin asymmetry appears in deep inelastic inclusive lepto-production at low transverse momenta when a hadron in the target fragmentation region is observed in association with another hadron in the current fragmentation region. The beam leptons are longitudinally polarized while the target nucleons are unpolarized. This asymmetry is a leading-twist effect generated by the correlation between the transverse momentum of quarks and the transverse momentum of the hadron emitted by the target. Experimental signatures of this effect are discussed.
[ { "created": "Mon, 12 Dec 2011 16:18:12 GMT", "version": "v1" } ]
2015-06-03
[ [ "Anselmino", "Mauro", "" ], [ "Barone", "Vincenzo", "" ], [ "Kotzinian", "Aram", "" ] ]
We show that a new beam-spin asymmetry appears in deep inelastic inclusive lepto-production at low transverse momenta when a hadron in the target fragmentation region is observed in association with another hadron in the current fragmentation region. The beam leptons are longitudinally polarized while the target nucleons are unpolarized. This asymmetry is a leading-twist effect generated by the correlation between the transverse momentum of quarks and the transverse momentum of the hadron emitted by the target. Experimental signatures of this effect are discussed.
1006.1331
Alexander Sorin
Oleg Rogachevsky, Alexander Sorin, Oleg Teryaev
Chiral vortaic effect and neutron asymmetries at NICA
LaTeX, 10 pages, 3 figures (V2: new figure and comments added)
Phys.Rev.C82:054910,2010
10.1103/PhysRevC.82.054910
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility of testing experimentally signatures of P-odd effects related with the vorticity of the medium. The Chiral Vortaic Effect is generalized to the case of conserved charges different from the electric one. In the case of baryonic charge and chemical potential such effect should manifest itself in neutron asymmetries at the NICA accelerator complex measured by the MPD detector. The required accuracy may be achieved in a few months of accelerator running. We also discuss polarization of the hyperons and P-odd correlations of particle momenta (handedness) as probes of vorticity.
[ { "created": "Mon, 7 Jun 2010 19:01:44 GMT", "version": "v1" }, { "created": "Sat, 25 Sep 2010 09:53:33 GMT", "version": "v2" } ]
2010-12-23
[ [ "Rogachevsky", "Oleg", "" ], [ "Sorin", "Alexander", "" ], [ "Teryaev", "Oleg", "" ] ]
We study the possibility of testing experimentally signatures of P-odd effects related with the vorticity of the medium. The Chiral Vortaic Effect is generalized to the case of conserved charges different from the electric one. In the case of baryonic charge and chemical potential such effect should manifest itself in neutron asymmetries at the NICA accelerator complex measured by the MPD detector. The required accuracy may be achieved in a few months of accelerator running. We also discuss polarization of the hyperons and P-odd correlations of particle momenta (handedness) as probes of vorticity.
2209.12161
Dongyan Fu
Dongyan Fu, Bao-Dong Sun, Yubing Dong
Generalized parton distributions in spin-3/2 particles
14 pages, 2 figures
null
10.1103/PhysRevD.106.116012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Generalized parton distribution functions (GPDs) of spin-3/2 particles are defined for the first time in this paper. Eight unpolarized and eight polarized GPDs are found. In the forward limit of GPDs, the structure functions and parton distribution functions are obtained. Then, the sum rules that connect the GPDs with the electromagnetic and gravitational form factors are explicitly displayed. Finally, the relations between GPDs and the helicity amplitudes of the system are derived.
[ { "created": "Sun, 25 Sep 2022 06:22:11 GMT", "version": "v1" }, { "created": "Thu, 29 Sep 2022 09:12:27 GMT", "version": "v2" }, { "created": "Mon, 26 Dec 2022 02:43:51 GMT", "version": "v3" } ]
2023-01-04
[ [ "Fu", "Dongyan", "" ], [ "Sun", "Bao-Dong", "" ], [ "Dong", "Yubing", "" ] ]
Generalized parton distribution functions (GPDs) of spin-3/2 particles are defined for the first time in this paper. Eight unpolarized and eight polarized GPDs are found. In the forward limit of GPDs, the structure functions and parton distribution functions are obtained. Then, the sum rules that connect the GPDs with the electromagnetic and gravitational form factors are explicitly displayed. Finally, the relations between GPDs and the helicity amplitudes of the system are derived.
hep-ph/9604353
Wolfgang Schweiger
P. Kroll, M. Schuermann, K. Passek, and W. Schweiger
Exclusive Photoproduction of Large Momentum-Transfer K and K* Mesons
32 pages, 7 figures available as tared, compressed and uuencoded PS-files
Phys.Rev. D55 (1997) 4315-4328
10.1103/PhysRevD.55.4315
UNIGRAZ-UTP 15-04-96, WU B 96-13
hep-ph
null
The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes of proton and Lambda are taken from previous investigations of electromagnetic baryon form factors and Compton-scattering off protons. Unpolarized differential cross sections and polarization observables are computed for different choices of the K and K* distribution amplitudes. The asymptotic form of the K distribution amplitude (proportional to x1 x2) is found to provide a satisfactory description of the K photoproduction data.
[ { "created": "Thu, 18 Apr 1996 17:28:58 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kroll", "P.", "" ], [ "Schuermann", "M.", "" ], [ "Passek", "K.", "" ], [ "Schweiger", "W.", "" ] ]
The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes of proton and Lambda are taken from previous investigations of electromagnetic baryon form factors and Compton-scattering off protons. Unpolarized differential cross sections and polarization observables are computed for different choices of the K and K* distribution amplitudes. The asymptotic form of the K distribution amplitude (proportional to x1 x2) is found to provide a satisfactory description of the K photoproduction data.
1105.0734
Shunsuke Ohkoda
Yasuhiro Yamaguchi, Shunsuke Ohkoda, Shigehiro Yasui, and Atsushi Hosaka
Exotic baryons from a heavy meson and a nucleon -- Negative parity states --
23 pages, 12 figures
Phys.Rev.D84:014032,2011
10.1103/PhysRevD.84.014032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study heavy baryons with an exotic flavor quantum number formed by a heavy meson and a nucleon (Dbar-N and B-N) through a long range one pion exchange interaction. The bound state found previously in the (I,JP) =(0,1/2-) channel survives when short range interaction is included. In addition, we find a resonant state with (I,JP)=(0,3/2-) as a Feshbach resonance predominated by a heavy vector meson and a nucleon (Dbar*-N and B*-N). We find that these exotic states exist for the charm and heavier flavor region.
[ { "created": "Wed, 4 May 2011 05:39:56 GMT", "version": "v1" }, { "created": "Fri, 6 May 2011 08:51:09 GMT", "version": "v2" }, { "created": "Thu, 19 May 2011 09:24:52 GMT", "version": "v3" } ]
2011-08-11
[ [ "Yamaguchi", "Yasuhiro", "" ], [ "Ohkoda", "Shunsuke", "" ], [ "Yasui", "Shigehiro", "" ], [ "Hosaka", "Atsushi", "" ] ]
We study heavy baryons with an exotic flavor quantum number formed by a heavy meson and a nucleon (Dbar-N and B-N) through a long range one pion exchange interaction. The bound state found previously in the (I,JP) =(0,1/2-) channel survives when short range interaction is included. In addition, we find a resonant state with (I,JP)=(0,3/2-) as a Feshbach resonance predominated by a heavy vector meson and a nucleon (Dbar*-N and B*-N). We find that these exotic states exist for the charm and heavier flavor region.
hep-ph/0102223
Andrei Kataev
A.L. Kataev (Theor. Phys. Div. of CERN, Geneva, Switzerland and Institute for Nuclear Research of the Academy of Sciencies of Russia, Moscow, Russia)
Light-quark masses and renormalons
14 pages, Contributed to the Proceedings of Quarks-2000 International Seminar, May 2000, Pushkin, Russia; minor typos are removed, 2 referencies are added
null
null
CERN-TH/2001-030
hep-ph
null
A brief review of the problem of the determination of light-quark masses from QCD sum rules for the correlators of scalar and pseudoscalar currents is given. Special attention is paid to the description of the large-$N_f$ results, obtained in collaboration with Broadhurst and Maxwell, for the scalar correlator, and estimates of its higher-order perturbative uncertainties within the renormalon-inspired large-$\beta_0$ expansion in the $\overline{\rm MS}$ scheme are given. Brief discussion is presented of the results of calculations of higher-order perturbative QCD corrections to the relation between pole and $\overline{\rm MS}$-scheme running-quark masses. Their comparison with the different estimates is also given.
[ { "created": "Sun, 18 Feb 2001 12:22:05 GMT", "version": "v1" }, { "created": "Mon, 28 May 2001 08:13:12 GMT", "version": "v2" } ]
2007-05-23
[ [ "Kataev", "A. L.", "", "Theor. Phys. Div. of CERN, Geneva, Switzerland and\n Institute for Nuclear Research of the Academy of Sciencies of Russia, Moscow,\n Russia" ] ]
A brief review of the problem of the determination of light-quark masses from QCD sum rules for the correlators of scalar and pseudoscalar currents is given. Special attention is paid to the description of the large-$N_f$ results, obtained in collaboration with Broadhurst and Maxwell, for the scalar correlator, and estimates of its higher-order perturbative uncertainties within the renormalon-inspired large-$\beta_0$ expansion in the $\overline{\rm MS}$ scheme are given. Brief discussion is presented of the results of calculations of higher-order perturbative QCD corrections to the relation between pole and $\overline{\rm MS}$-scheme running-quark masses. Their comparison with the different estimates is also given.
0710.0123
Xiang Liu
Xiang Liu, Hua-Xing Chen, Yan-Rui Liu, Atsushi Hosaka and Shi-Lin Zhu
Bottom Baryons
8 pages, 5 figures, 3 tables. More discussions and references added
Phys.Rev.D77:014031,2008
10.1103/PhysRevD.77.014031
null
hep-ph hep-ex nucl-ex nucl-th
null
Recently CDF and D0 collaborations observed several bottom baryons. In this work we perform a systematic study of the masses of bottom baryons up to $1/m_Q$ in the framework of heavy quark effective field theory (HQET) using the QCD sum rule approach. The extracted chromo-magnetic splitting between the bottom baryon heavy doublet agrees well with the experimental data.
[ { "created": "Sun, 30 Sep 2007 10:49:34 GMT", "version": "v1" }, { "created": "Thu, 8 Nov 2007 02:06:07 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liu", "Xiang", "" ], [ "Chen", "Hua-Xing", "" ], [ "Liu", "Yan-Rui", "" ], [ "Hosaka", "Atsushi", "" ], [ "Zhu", "Shi-Lin", "" ] ]
Recently CDF and D0 collaborations observed several bottom baryons. In this work we perform a systematic study of the masses of bottom baryons up to $1/m_Q$ in the framework of heavy quark effective field theory (HQET) using the QCD sum rule approach. The extracted chromo-magnetic splitting between the bottom baryon heavy doublet agrees well with the experimental data.
hep-ph/9602269
Koichi Funakubo
K.Funakubo, A.Kakuto, S.Otsuki and F.Toyoda
Numerical Approach to CP-Violating Dirac Equation
14 pages, epsf.sty is needed, 3 figures appended
Prog.Theor.Phys. 95 (1996) 929-942
10.1143/PTP.95.929
SAGA-HE-99
hep-ph
null
We propose a new method to evaluate the chiral charge flux, which is converted into baryon number in the framework of the charge transport scenario of electroweak baryogenesis. By the new method, one can calculate the flux in the background of any type of bubble wall with any desired accuracy.
[ { "created": "Sat, 10 Feb 1996 13:31:01 GMT", "version": "v1" } ]
2009-10-28
[ [ "Funakubo", "K.", "" ], [ "Kakuto", "A.", "" ], [ "Otsuki", "S.", "" ], [ "Toyoda", "F.", "" ] ]
We propose a new method to evaluate the chiral charge flux, which is converted into baryon number in the framework of the charge transport scenario of electroweak baryogenesis. By the new method, one can calculate the flux in the background of any type of bubble wall with any desired accuracy.
1403.7490
James Ferrando
Nicolas Gutierrez Ortiz, James Ferrando, Deepak Kar, Michael Spannowsky
Reconstructing singly produced top partners in decays to $\mathbf{Wb}$
5 pages, 3 figures (v2 updated physics content to match version accepted by PRD)
Phys. Rev. D 90, 075009 (2014)
10.1103/PhysRevD.90.075009
IPPP/14/25, GLAS-PPE/2014-01, DCPT/14/50
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fermionic top partners are a feature of many models of physics beyond the Standard Model. We propose a search strategy for single production of top partners focussing specifically on the dominant decay to $Wb$. The enormous background can be reduced by requiring a forward jet and exploiting jet substructure to suppress top-pair production. This simple strategy is shown to produce a sensitive search for single top-partner production, in the context of composite Higgs models, that has competitive mass reach with existing experimental searches for top-partner-pair production at the 8TeV LHC.
[ { "created": "Fri, 28 Mar 2014 19:11:12 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 2014 10:51:39 GMT", "version": "v2" } ]
2014-10-16
[ [ "Ortiz", "Nicolas Gutierrez", "" ], [ "Ferrando", "James", "" ], [ "Kar", "Deepak", "" ], [ "Spannowsky", "Michael", "" ] ]
Fermionic top partners are a feature of many models of physics beyond the Standard Model. We propose a search strategy for single production of top partners focussing specifically on the dominant decay to $Wb$. The enormous background can be reduced by requiring a forward jet and exploiting jet substructure to suppress top-pair production. This simple strategy is shown to produce a sensitive search for single top-partner production, in the context of composite Higgs models, that has competitive mass reach with existing experimental searches for top-partner-pair production at the 8TeV LHC.
2111.08263
Mrinal Kumar Das
Lavina Sarma and Mrinal Kumar Das
Phenomenology of one zero texture Yukawa matrix in a flavor symmetric scotogenic model
31 pages, 12 figures, 2 tables. Accepted for publication in IJMPA
null
10.1142/S0217751X2250083X
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The scotogenic model is well known for accommodating small neutrino mass and dark matter. Here, we have realized the scotogenic model with the help of discrete flavor symmetry $A_{4}\otimes Z_{4}$. We have obtained three one zero textures of Yukawa coupling matrices from the model and have studied its impact on neutrino phenomenology and related aspects of cosmology. On the basis of $\mu-\tau$ symmetry, we have further discarded two structures of one zero texture Yukawa coupling matrix. We further analyze if the effective mass of active neutrinos obtained by the virtue of the Yukawa coupling matrix is consistent with the KamLAND-Zen limit for 0$\nu\beta\beta$. Also different lepton flavor violating(LFV) processes such as $l_{\alpha}\longrightarrow l_{\beta}\gamma$ and $l_{\alpha}\longrightarrow 3l_{\beta}$ are implemented and their influence on neutrino phenomenology is studied corresponding to the Yukawa coupling matrix. The entire work is carried out considering the dark matter mass($M_{DM}$) in the region $450-750$ GeV. We have also obtained some significant results for baryon asymmetry of the Universe in agreement with the one zero textures of the coupling matrices. Furthermore, interesting results for relic abundance on the basis of distinct mass splittings between the inert scalars.
[ { "created": "Tue, 16 Nov 2021 07:11:40 GMT", "version": "v1" }, { "created": "Mon, 23 May 2022 06:16:01 GMT", "version": "v2" } ]
2022-06-29
[ [ "Sarma", "Lavina", "" ], [ "Das", "Mrinal Kumar", "" ] ]
The scotogenic model is well known for accommodating small neutrino mass and dark matter. Here, we have realized the scotogenic model with the help of discrete flavor symmetry $A_{4}\otimes Z_{4}$. We have obtained three one zero textures of Yukawa coupling matrices from the model and have studied its impact on neutrino phenomenology and related aspects of cosmology. On the basis of $\mu-\tau$ symmetry, we have further discarded two structures of one zero texture Yukawa coupling matrix. We further analyze if the effective mass of active neutrinos obtained by the virtue of the Yukawa coupling matrix is consistent with the KamLAND-Zen limit for 0$\nu\beta\beta$. Also different lepton flavor violating(LFV) processes such as $l_{\alpha}\longrightarrow l_{\beta}\gamma$ and $l_{\alpha}\longrightarrow 3l_{\beta}$ are implemented and their influence on neutrino phenomenology is studied corresponding to the Yukawa coupling matrix. The entire work is carried out considering the dark matter mass($M_{DM}$) in the region $450-750$ GeV. We have also obtained some significant results for baryon asymmetry of the Universe in agreement with the one zero textures of the coupling matrices. Furthermore, interesting results for relic abundance on the basis of distinct mass splittings between the inert scalars.
hep-ph/0301075
Ralf Hofmann
Ralf Hofmann and Maxim Pospelov
Conformal matter in warped backgrounds
9 pages
Phys.Lett. B556 (2003) 203-208
10.1016/S0370-2693(03)00135-7
HD-THEP-02-45, UVIC-TH-02-06
hep-ph
null
Warped backgrounds in five dimensional models can provide solutions to various hierarchy problems in particle physics if the standard model matter is associated with the zero modes of bulk fields with nontrivial profiles along the extra dimension. We investigate the case of a {\sl conformally} coupled massless scalar. This field possesses a zero mode whose action density is exponentially enhanced along the transverse direction in a warped background, {\em i.e.} near the negative tension brane in the RS setting. At the zero mode level effective 5D composites of this scalar and its derivatives, which are suppressed by powers of the fundamental gravitational scale, yield 4D interactions of electroweak strength. This suggests a certain importance of conformally coupled scalar fields for extra-dimensional model building.
[ { "created": "Sat, 11 Jan 2003 15:43:43 GMT", "version": "v1" } ]
2009-11-10
[ [ "Hofmann", "Ralf", "" ], [ "Pospelov", "Maxim", "" ] ]
Warped backgrounds in five dimensional models can provide solutions to various hierarchy problems in particle physics if the standard model matter is associated with the zero modes of bulk fields with nontrivial profiles along the extra dimension. We investigate the case of a {\sl conformally} coupled massless scalar. This field possesses a zero mode whose action density is exponentially enhanced along the transverse direction in a warped background, {\em i.e.} near the negative tension brane in the RS setting. At the zero mode level effective 5D composites of this scalar and its derivatives, which are suppressed by powers of the fundamental gravitational scale, yield 4D interactions of electroweak strength. This suggests a certain importance of conformally coupled scalar fields for extra-dimensional model building.
1111.0949
Leonid Glozman
L. Ya. Glozman, V. K. Sazonov, R. F. Wagenbrunn
Chiral restoration phase transition within the quarkyonic matter
9 pp, Presented at "Three Days on Quarkyonic Island", 19-21 May, 2011, Wroclaw, Poland
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We overview a possible mechanism for confining but chirally symmetric matter at low temperatures and large densities. As a new development we employ a diffused quark Fermi surface and show that such diffusion does not destroy possible existence of a confining but chirally symmetric matter at low temperatures and large density.
[ { "created": "Thu, 3 Nov 2011 19:12:18 GMT", "version": "v1" } ]
2011-11-04
[ [ "Glozman", "L. Ya.", "" ], [ "Sazonov", "V. K.", "" ], [ "Wagenbrunn", "R. F.", "" ] ]
We overview a possible mechanism for confining but chirally symmetric matter at low temperatures and large densities. As a new development we employ a diffused quark Fermi surface and show that such diffusion does not destroy possible existence of a confining but chirally symmetric matter at low temperatures and large density.
1001.3730
Shigehiro Yasui
Shigehiro Yasui, Kazunori Itakura, Muneto Nitta
Fermion structure of non-Abelian vortices in high density QCD
10 pages, 3 figures, clarification added in Introduction, reference added
Phys.Rev.D81:105003,2010
10.1103/PhysRevD.81.105003
KEK-TH-1349
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the internal structure of a non-Abelian vortex in color superconductivity with respect to quark degrees of freedom. Stable non-Abelian vortices appear in the Color-Flavor-Locked phase whose symmetry SU(3)_{c+L+R} is further broken to SU(2)_{c+L+R} x U(1)_{c+L+R} at the vortex cores. Microscopic structure of vortices at scales shorter than the coherence length can be analyzed by the Bogoliubov-de Gennes (B-dG) equation (rather than the Ginzburg-Landau equation). We obtain quark spectra from the B-dG equation by treating the diquark gap having the vortex configuration as a background field. We find that there are massless modes (zero modes) well-localized around a vortex, in the triplet and singlet states of the unbroken symmetry SU(2)_{c+L+R} x U(1)_{c+L+R}. The velocities v_i of the massless modes (i=t,s for triplet and singlet) change at finite chemical potential \mu, and decrease as \mu becomes large. Therefore, low energy excitations in the vicinity of the vortices are effectively described by 1+1 dimensional massless fermions whose velocities are reduced v_i<1.
[ { "created": "Thu, 21 Jan 2010 06:23:15 GMT", "version": "v1" }, { "created": "Fri, 5 Feb 2010 12:24:04 GMT", "version": "v2" } ]
2010-11-15
[ [ "Yasui", "Shigehiro", "" ], [ "Itakura", "Kazunori", "" ], [ "Nitta", "Muneto", "" ] ]
We study the internal structure of a non-Abelian vortex in color superconductivity with respect to quark degrees of freedom. Stable non-Abelian vortices appear in the Color-Flavor-Locked phase whose symmetry SU(3)_{c+L+R} is further broken to SU(2)_{c+L+R} x U(1)_{c+L+R} at the vortex cores. Microscopic structure of vortices at scales shorter than the coherence length can be analyzed by the Bogoliubov-de Gennes (B-dG) equation (rather than the Ginzburg-Landau equation). We obtain quark spectra from the B-dG equation by treating the diquark gap having the vortex configuration as a background field. We find that there are massless modes (zero modes) well-localized around a vortex, in the triplet and singlet states of the unbroken symmetry SU(2)_{c+L+R} x U(1)_{c+L+R}. The velocities v_i of the massless modes (i=t,s for triplet and singlet) change at finite chemical potential \mu, and decrease as \mu becomes large. Therefore, low energy excitations in the vicinity of the vortices are effectively described by 1+1 dimensional massless fermions whose velocities are reduced v_i<1.
hep-ph/9704408
Brett van de Sande
S. Dalley, B. van de Sande
Colour-Dielectric Gauge Theory on a Transverse Lattice
48 pages, Latex, uses macro boxedeps.tex, minor errors corrected in revised version
Phys. Rev. D 56, 7917 (1997)
10.1103/PhysRevD.56.7917
DAMTP-97-16
hep-ph hep-lat hep-th
null
We investigate in some detail consequences of the effective colour-dielectric formulation of lattice gauge theory using the light-cone Hamiltonian formalism with a transverse lattice. As a quantitative test of this approach, we have performed extensive analytic and numerical calculations for 2+1-dimensional pure gauge theory in the large N limit. Because of Eguchi-Kawai reduction, one effectively studies a 1+1-dimensional gauge theory coupled to matter in the adjoint representation. We study the structure of coupling constant space for our effective potential by comparing with the physical results available from conventional Euclidean lattice Monte Carlo simulations of this system. In particular, we calculate and measure the scaling behaviour of the entire low-lying glueball spectrum, glueball wavefunctions, string tension, asymptotic density of states, and deconfining temperature. We employ a new hybrid DLCQ/wavefunction basis in our calculations of the light-cone Hamiltonian matrix elements, along with extrapolation in Tamm-Dancoff truncation, significantly reducing numerical errors. Finally we discuss, in light of our results, what further measurements and calculations could be made in order to systematically remove lattice spacing dependence from our effective potential a priori.
[ { "created": "Sat, 26 Apr 1997 17:07:01 GMT", "version": "v1" }, { "created": "Thu, 23 Oct 1997 10:07:04 GMT", "version": "v2" }, { "created": "Thu, 15 Oct 1998 13:57:36 GMT", "version": "v3" } ]
2016-08-25
[ [ "Dalley", "S.", "" ], [ "van de Sande", "B.", "" ] ]
We investigate in some detail consequences of the effective colour-dielectric formulation of lattice gauge theory using the light-cone Hamiltonian formalism with a transverse lattice. As a quantitative test of this approach, we have performed extensive analytic and numerical calculations for 2+1-dimensional pure gauge theory in the large N limit. Because of Eguchi-Kawai reduction, one effectively studies a 1+1-dimensional gauge theory coupled to matter in the adjoint representation. We study the structure of coupling constant space for our effective potential by comparing with the physical results available from conventional Euclidean lattice Monte Carlo simulations of this system. In particular, we calculate and measure the scaling behaviour of the entire low-lying glueball spectrum, glueball wavefunctions, string tension, asymptotic density of states, and deconfining temperature. We employ a new hybrid DLCQ/wavefunction basis in our calculations of the light-cone Hamiltonian matrix elements, along with extrapolation in Tamm-Dancoff truncation, significantly reducing numerical errors. Finally we discuss, in light of our results, what further measurements and calculations could be made in order to systematically remove lattice spacing dependence from our effective potential a priori.
1703.10600
Sylvain Fichet
Cristian Baldenegro, Sylvain Fichet, Gero von Gersdorff, Christophe Royon
Probing the anomalous $\gamma\gamma\gamma Z$ coupling at the LHC with proton tagging
16 pages, 6 figures. v2 matches journal version
JHEP 1706 (2017) 142
10.1007/JHEP06(2017)142
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The sensitivities to the anomalous quartic gauge boson coupling $\gamma\gamma\gamma Z$ are estimated via $\gamma Z$ production with intact protons in the forward region at the LHC. Proton tagging proves to be a powerful tool to suppress the background, which allows consideration of the hadronic decays of the $Z$ boson in addition to the leptonic ones. We discuss the discovery potential for an integrated luminosity of $300\,\mathrm{fb}^{-1}$ and $3000\,\mathrm{fb}^{-1}$. The sensitivity we obtain at $300\,\mathrm{fb}^{-1}$ goes beyond the one expected from LHC bounds on the $Z\rightarrow \gamma\gamma\gamma$ decay by about three orders of magnitude. The $\gamma Z$ channel provides important discriminatory information with respect to the exclusive $\gamma\gamma$ channel, as many particles beyond the Standard Model (such as a radion or Kaluza Klein gravitons) predict a signal in the latter but not the former.
[ { "created": "Thu, 30 Mar 2017 17:56:22 GMT", "version": "v1" }, { "created": "Thu, 24 Aug 2017 20:04:00 GMT", "version": "v2" } ]
2017-08-28
[ [ "Baldenegro", "Cristian", "" ], [ "Fichet", "Sylvain", "" ], [ "von Gersdorff", "Gero", "" ], [ "Royon", "Christophe", "" ] ]
The sensitivities to the anomalous quartic gauge boson coupling $\gamma\gamma\gamma Z$ are estimated via $\gamma Z$ production with intact protons in the forward region at the LHC. Proton tagging proves to be a powerful tool to suppress the background, which allows consideration of the hadronic decays of the $Z$ boson in addition to the leptonic ones. We discuss the discovery potential for an integrated luminosity of $300\,\mathrm{fb}^{-1}$ and $3000\,\mathrm{fb}^{-1}$. The sensitivity we obtain at $300\,\mathrm{fb}^{-1}$ goes beyond the one expected from LHC bounds on the $Z\rightarrow \gamma\gamma\gamma$ decay by about three orders of magnitude. The $\gamma Z$ channel provides important discriminatory information with respect to the exclusive $\gamma\gamma$ channel, as many particles beyond the Standard Model (such as a radion or Kaluza Klein gravitons) predict a signal in the latter but not the former.
2301.05407
T. Phong Nguyen
L.T. Hue, H. N. Long, V. H. Binh, H. L. T. Mai, T. Phong Nguyen
One-loop contributions to decays $e_b\to e_a \gamma$ and $(g-2)_{e_a}$ anomalies, and Ward identity
The version accepted to Nuclear Physics B
Nucl.Phys.B 992 (2023) 116244
10.1016/j.nuclphysb.2023.116244
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we will present analytic formulas to express one-loop contributions to lepton flavor violating decays $e_b\to e_a \gamma$, which are also relevant to the anomalous dipole magnetic moments of charged leptons $e_a$. These formulas were computed in the unitary gauge, using the well-known Passarino-Veltman notations. We also show that our results are consistent with those calculated previously in the 't Hooft-Veltman gauge, or in the limit of zero lepton masses. At the one-loop level, we show that the appearance of fermion-scalar-vector type diagrams in the unitary gauge will violate the Ward Identity relating to an external photon. As a result, the validation of the Ward Identity guarantees that the photon always couples with two identical particles in an arbitrary triple coupling vertex containing a photon.
[ { "created": "Fri, 13 Jan 2023 06:33:02 GMT", "version": "v1" }, { "created": "Thu, 25 May 2023 07:02:17 GMT", "version": "v2" } ]
2023-06-02
[ [ "Hue", "L. T.", "" ], [ "Long", "H. N.", "" ], [ "Binh", "V. H.", "" ], [ "Mai", "H. L. T.", "" ], [ "Nguyen", "T. Phong", "" ] ]
In this paper, we will present analytic formulas to express one-loop contributions to lepton flavor violating decays $e_b\to e_a \gamma$, which are also relevant to the anomalous dipole magnetic moments of charged leptons $e_a$. These formulas were computed in the unitary gauge, using the well-known Passarino-Veltman notations. We also show that our results are consistent with those calculated previously in the 't Hooft-Veltman gauge, or in the limit of zero lepton masses. At the one-loop level, we show that the appearance of fermion-scalar-vector type diagrams in the unitary gauge will violate the Ward Identity relating to an external photon. As a result, the validation of the Ward Identity guarantees that the photon always couples with two identical particles in an arbitrary triple coupling vertex containing a photon.
hep-ph/0111271
Ramona Vogt
R. Vogt (LBNL and UC Davis)
The A Dependence of Open Charm and Bottom Production
69 pages, 42 .eps figures, to appear in the Proceedings of the Hard Probe Collaboration
Int.J.Mod.Phys.E12:211-270,2003
10.1142/S0218301303001272
LBNL-45350
hep-ph
null
We study inclusive heavy quark and exclusive heavy quark pair production in pp, pA and AA interactions. Intrinsic transverse momentum is introduced in pp interactions. Nuclear effects, limited to $k_T$ broadening and nuclear shadowing, are introduced in pA and AA interactions. The nuclear dependence is studied over a range of energies, both in fixed target and collider setups.
[ { "created": "Thu, 22 Nov 2001 00:13:28 GMT", "version": "v1" } ]
2016-09-06
[ [ "Vogt", "R.", "", "LBNL and UC Davis" ] ]
We study inclusive heavy quark and exclusive heavy quark pair production in pp, pA and AA interactions. Intrinsic transverse momentum is introduced in pp interactions. Nuclear effects, limited to $k_T$ broadening and nuclear shadowing, are introduced in pA and AA interactions. The nuclear dependence is studied over a range of energies, both in fixed target and collider setups.
2308.14950
Terry Mart
M. Ridwan and T. Mart
Note on the electromagnetic radius of proton
25 pages, 9 figures, submitted to Modern Physics Letters A
Modern Physics Letters A 38 (2023) 2350157
10.1142/S0217732323501572
null
hep-ph nucl-ex nucl-th physics.pop-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have analyzed the proton form factor data by using a number of phenomenological parameterizations (models) and extracting the proton electric and magnetic radii. To this end we performed a global fit to all available form factor data, with the virtual photon momentum squared $Q^2$ from $0.0002$ to nearly 10 GeV$^2$ for electric form factor and from $0.015$ to 31 GeV$^2$ for magnetic one. Special attention was given to the small structure shown by the form factor data near $Q^2 = 0.2$ GeV$^2$. It was found that different models yield different structures with different numbers of minimum at this kinematics. Since the slope of form factor in the limit of $Q^2\to 0$ is influenced by this structure, the extracted proton radii are consequently different for different models. Our finding recommends that future experiments should focus on this kinematics instead of low $Q^2$. Experimental data with accuracies comparable to those of the latest data at low $Q^2$ would clearly help to clarify the effect of this structure on the proton charge radius. Interestingly, most of the extracted proton charge radii were found to be closer to the value obtained from the muonic hydrogen atom spectroscopy.
[ { "created": "Tue, 29 Aug 2023 00:40:29 GMT", "version": "v1" } ]
2024-01-12
[ [ "Ridwan", "M.", "" ], [ "Mart", "T.", "" ] ]
We have analyzed the proton form factor data by using a number of phenomenological parameterizations (models) and extracting the proton electric and magnetic radii. To this end we performed a global fit to all available form factor data, with the virtual photon momentum squared $Q^2$ from $0.0002$ to nearly 10 GeV$^2$ for electric form factor and from $0.015$ to 31 GeV$^2$ for magnetic one. Special attention was given to the small structure shown by the form factor data near $Q^2 = 0.2$ GeV$^2$. It was found that different models yield different structures with different numbers of minimum at this kinematics. Since the slope of form factor in the limit of $Q^2\to 0$ is influenced by this structure, the extracted proton radii are consequently different for different models. Our finding recommends that future experiments should focus on this kinematics instead of low $Q^2$. Experimental data with accuracies comparable to those of the latest data at low $Q^2$ would clearly help to clarify the effect of this structure on the proton charge radius. Interestingly, most of the extracted proton charge radii were found to be closer to the value obtained from the muonic hydrogen atom spectroscopy.
hep-ph/9803203
Pankaj Agrawal
Pankaj Agrawal
More Signatures of the Intermediate Mass Higgs Boson
10 pages, LaTeX file
Mod.Phys.Lett. A14 (1999) 1479-1486
10.1142/S0217732399001577
IP/BBSR/98-6
hep-ph
null
We examine the potential signatures of the Higgs boson when it decays into a tau-lepton pair. We show that with the proper identification of the tau-jet, this decay mode can lead to the identification of the Higgs boson over most of the intermediate mass range (\mW $<$ \mH $<$ 2 \mW).
[ { "created": "Sat, 28 Feb 1998 10:57:00 GMT", "version": "v1" } ]
2009-10-31
[ [ "Agrawal", "Pankaj", "" ] ]
We examine the potential signatures of the Higgs boson when it decays into a tau-lepton pair. We show that with the proper identification of the tau-jet, this decay mode can lead to the identification of the Higgs boson over most of the intermediate mass range (\mW $<$ \mH $<$ 2 \mW).
hep-ph/0502087
J. -Alexis Rodriguez L.
R. Martinez (1), D. A. Milanes (1,2) and J.-Alexis Rodriguez (1)
The lightest Higgs boson production at photon colliders in the 2HDM-III
1. Universidad Nacional de Colombia, Bogota, Colombia. (2) Universidad de Valencia, Valencia, Spain. 21 pages, 5 figures, RevTeX
Phys.Rev. D72 (2005) 035017
10.1103/PhysRevD.72.035017
null
hep-ph
null
The branching ratios of the lightest CP-even Higgs boson $h^0$, in the framework of the General Two Higgs Doublet Model are calculated. Different scenarios are presented taking into account constraints obtained in previous works on the flavor changing neutral currents factors. Plausible scenarios with flavour changing processes at tree level like $b \bar s$ and $t \bar c$ are analyzed for relevant region of parameters. The loop-induced Higgs couplings to photon pairs can be tested with a photon collider. The number of events of $h^0$ as a resonance in photon colliders are calculated taking into account its corresponding background signal in TESLA, CLIC and NLC.
[ { "created": "Wed, 9 Feb 2005 15:06:37 GMT", "version": "v1" } ]
2009-11-11
[ [ "Martinez", "R.", "" ], [ "Milanes", "D. A.", "" ], [ "Rodriguez", "J. -Alexis", "" ] ]
The branching ratios of the lightest CP-even Higgs boson $h^0$, in the framework of the General Two Higgs Doublet Model are calculated. Different scenarios are presented taking into account constraints obtained in previous works on the flavor changing neutral currents factors. Plausible scenarios with flavour changing processes at tree level like $b \bar s$ and $t \bar c$ are analyzed for relevant region of parameters. The loop-induced Higgs couplings to photon pairs can be tested with a photon collider. The number of events of $h^0$ as a resonance in photon colliders are calculated taking into account its corresponding background signal in TESLA, CLIC and NLC.
2111.06196
Prabal Adhikari
Prabal Adhikari
QCD $\theta$-vacuum in a Uniform Magnetic Field
18 pages, 5 figures
null
10.1016/j.nuclphysb.2021.115627
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $\theta$-vacuum of QCD using two-flavor chiral perturbation theory ($\chi$PT) in the presence of a uniform, background magnetic field calculating the magnetic field-dependent free energy density, the topological density, the topological susceptibility and the fourth cumulant at one-loop order. We find that the topological susceptibility is enhanced by the magnetic field while the fourth topological cumulant is diminished at weak fields and enhanced at larger fields when $\theta=0$. However, in the QCD vacuum with $\theta\neq 0$, the topological susceptibility can be either monotonically enhanced or diminished relative to their $\theta$-vacuum values. The fourth cumulant also exhibits monotonic enhancement or suppression except for regions of $\theta$ near $0$ and $2\pi$, where it is both diminished and enhanced. Finally, the topological density is enhanced for all magnetic fields with its relative shift being identical to the relative shift of the up and down quark condensates in the $\theta$-vacuum.
[ { "created": "Thu, 11 Nov 2021 13:30:09 GMT", "version": "v1" } ]
2022-01-26
[ [ "Adhikari", "Prabal", "" ] ]
We study the $\theta$-vacuum of QCD using two-flavor chiral perturbation theory ($\chi$PT) in the presence of a uniform, background magnetic field calculating the magnetic field-dependent free energy density, the topological density, the topological susceptibility and the fourth cumulant at one-loop order. We find that the topological susceptibility is enhanced by the magnetic field while the fourth topological cumulant is diminished at weak fields and enhanced at larger fields when $\theta=0$. However, in the QCD vacuum with $\theta\neq 0$, the topological susceptibility can be either monotonically enhanced or diminished relative to their $\theta$-vacuum values. The fourth cumulant also exhibits monotonic enhancement or suppression except for regions of $\theta$ near $0$ and $2\pi$, where it is both diminished and enhanced. Finally, the topological density is enhanced for all magnetic fields with its relative shift being identical to the relative shift of the up and down quark condensates in the $\theta$-vacuum.
1009.4643
Tomoi Koide
Tomoi Koide
Non-Newtonian Properties of Relativistic Fluids
16 pages, 10 figures, Invited Lecture at the Fourth Mexican Meeting on Mathematical and Experimental Physics, 19th to 23th July, 2010, El Colegio Nacional, M\'exico
AIP Conf.Proc.1312:27-38,2010
10.1063/1.3533203
null
hep-ph cond-mat.stat-mech nucl-th physics.flu-dyn
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that relativistic fluids behave as non-Newtonian fluids. First, we discuss the problem of acausal propagation in the diffusion equation and introduce the modified Maxwell-Cattaneo-Vernotte (MCV) equation. By using the modified MCV equation, we obtain the causal dissipative relativistic (CDR) fluid dynamics, where unphysical propagation with infinite velocity does not exist. We further show that the problems of the violation of causality and instability are intimately related, and the relativistic Navier-Stokes equation is inadequate as the theory of relativistic fluids. Finally, the new microscopic formula to calculate the transport coefficients of the CDR fluid dynamics is discussed. The result of the microscopic formula is consistent with that of the Boltzmann equation, i.e., Grad's moment method.
[ { "created": "Thu, 23 Sep 2010 16:01:42 GMT", "version": "v1" } ]
2015-05-20
[ [ "Koide", "Tomoi", "" ] ]
We show that relativistic fluids behave as non-Newtonian fluids. First, we discuss the problem of acausal propagation in the diffusion equation and introduce the modified Maxwell-Cattaneo-Vernotte (MCV) equation. By using the modified MCV equation, we obtain the causal dissipative relativistic (CDR) fluid dynamics, where unphysical propagation with infinite velocity does not exist. We further show that the problems of the violation of causality and instability are intimately related, and the relativistic Navier-Stokes equation is inadequate as the theory of relativistic fluids. Finally, the new microscopic formula to calculate the transport coefficients of the CDR fluid dynamics is discussed. The result of the microscopic formula is consistent with that of the Boltzmann equation, i.e., Grad's moment method.
2405.14773
Francesco Giovanni Celiberto
Francesco Giovanni Celiberto, Gabriele Gatto, Alessandro papa
Fully charmed tetraquarks from LHC to FCC: Natural stability from fragmentation
56 pages, 13 figures
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the inclusive production of fully charmed tetraquarks, $T_{4c}(0^{++})$ or $T_{4c}(2^{++})$ radial excitations, in high-energy proton collisions. We build our study upon the collinear fragmentation of a single parton in a variable-flavor number scheme, suited to describe the tetraquark formation mechanism from moderate to large transverse-momentum regimes. To this extent, we derive a novel set of DGLAP-evolving collinear fragmentation functions, named TQ4Q1.0 determinations. They encode initial-scale inputs corresponding to both gluon and heavy-quark fragmentation channels, defined within the context of quark-potential and spin-physics inspired models, respectively. We work within the NLL/NLO$^+$ hybrid factorization and make use of the JETHAD numeric interface along with the symJETHAD symbolic calculation plugin. With these tools, we provide predictions for high-energy observables sensitive to $T_{4c}$ plus jet emissions at center-of-mass energies ranging from 14 TeV at the LHC to the 100 TeV nominal energy of the FCC.
[ { "created": "Thu, 23 May 2024 16:42:34 GMT", "version": "v1" } ]
2024-05-24
[ [ "Celiberto", "Francesco Giovanni", "" ], [ "Gatto", "Gabriele", "" ], [ "papa", "Alessandro", "" ] ]
We investigate the inclusive production of fully charmed tetraquarks, $T_{4c}(0^{++})$ or $T_{4c}(2^{++})$ radial excitations, in high-energy proton collisions. We build our study upon the collinear fragmentation of a single parton in a variable-flavor number scheme, suited to describe the tetraquark formation mechanism from moderate to large transverse-momentum regimes. To this extent, we derive a novel set of DGLAP-evolving collinear fragmentation functions, named TQ4Q1.0 determinations. They encode initial-scale inputs corresponding to both gluon and heavy-quark fragmentation channels, defined within the context of quark-potential and spin-physics inspired models, respectively. We work within the NLL/NLO$^+$ hybrid factorization and make use of the JETHAD numeric interface along with the symJETHAD symbolic calculation plugin. With these tools, we provide predictions for high-energy observables sensitive to $T_{4c}$ plus jet emissions at center-of-mass energies ranging from 14 TeV at the LHC to the 100 TeV nominal energy of the FCC.
hep-ph/0409082
Yoshiharu Kawamura
Yoshiharu Kawamura
Equivalence Classes in Gauge Theory on the Orbifold $S^1/Z_2$
4 pages, Talk given at the 12th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2004) June 17-23, 2004, Tsukuba, Japan
null
null
null
hep-ph
null
After a brief review of orbifold grand unified theory, we discuss two topics related to the choice of boundary conditions on the orbifold $S^1/Z_2$: dynamical rearrangement of gauge symmetry and equivalence classes of boundary conditions.
[ { "created": "Wed, 8 Sep 2004 01:46:57 GMT", "version": "v1" } ]
2009-09-29
[ [ "Kawamura", "Yoshiharu", "" ] ]
After a brief review of orbifold grand unified theory, we discuss two topics related to the choice of boundary conditions on the orbifold $S^1/Z_2$: dynamical rearrangement of gauge symmetry and equivalence classes of boundary conditions.
2304.03504
Irinel Caprini
Irinel Caprini
Resurgent representation of the Adler function in the large-$\beta_0$ approximation of QCD
Accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.107.074035
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Using a full resummation of the Adler function in the large-$\beta_0$ approximation of QCD and a mathematical framework of resurgence suitable for the specific properties of the Borel transform in this particular case, we derive a compact resurgent representation of the QCD Adler function, valid in the whole complex momentum plane. The representation is expressed in terms of the inverse Mellin transform of the Borel function and is analytic in the complex momentum plane, except for cuts along the timelike axis and the Landau region of the spacelike axis. It contains a purely nonperturbative term singular at the origin of the coupling plane, depending on a single real arbitrary constant. We compare the resurgent Adler function derived in this work with a previous determination in a similar framework and use its values in the complex plane for a calculation of the hadronic width of the $\tau$ lepton in the Standard Model.
[ { "created": "Fri, 7 Apr 2023 06:50:29 GMT", "version": "v1" } ]
2023-05-10
[ [ "Caprini", "Irinel", "" ] ]
Using a full resummation of the Adler function in the large-$\beta_0$ approximation of QCD and a mathematical framework of resurgence suitable for the specific properties of the Borel transform in this particular case, we derive a compact resurgent representation of the QCD Adler function, valid in the whole complex momentum plane. The representation is expressed in terms of the inverse Mellin transform of the Borel function and is analytic in the complex momentum plane, except for cuts along the timelike axis and the Landau region of the spacelike axis. It contains a purely nonperturbative term singular at the origin of the coupling plane, depending on a single real arbitrary constant. We compare the resurgent Adler function derived in this work with a previous determination in a similar framework and use its values in the complex plane for a calculation of the hadronic width of the $\tau$ lepton in the Standard Model.
2312.02787
Uliana Voznaya
U.E. Voznaya, A.B.Arbuzov
Radiative corrections of the order $\mathcal{O}(\alpha^3L^3)$ to unpolarized muon decay spectrum
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Calculation of higher-order radiative corrections to unpolarized muon decay spectrum is discussed. Results for the orders $\mathcal{O}(\alpha^2 L)$, $\mathcal{O}(\alpha^3 L^3)$ and $\mathcal{O}(\alpha^3 L^2)$ are presented.
[ { "created": "Tue, 5 Dec 2023 14:18:08 GMT", "version": "v1" } ]
2023-12-06
[ [ "Voznaya", "U. E.", "" ], [ "Arbuzov", "A. B.", "" ] ]
Calculation of higher-order radiative corrections to unpolarized muon decay spectrum is discussed. Results for the orders $\mathcal{O}(\alpha^2 L)$, $\mathcal{O}(\alpha^3 L^3)$ and $\mathcal{O}(\alpha^3 L^2)$ are presented.
hep-ph/9401305
null
E. Pallante and R. Petronzio
Quark-Resonance model
41 pages, 11 figures, preprint ROM2F 93/37
Z.Phys. C65 (1995) 487-504
10.1007/BF01556137
null
hep-ph
null
We construct an effective Lagrangian for low energy hadronic interactions through an infinite expansion in inverse powers of the low energy cutoff $\Lambda_\chi$ of all possible chiral invariant non-renormalizable interactions between quarks and mesons degrees of freedom. We restrict our analysis to the leading terms in the $1/N_c$ expansion. The effective expansion is in $(\mu^2/\cutoff^2 )^P \ln (\cutoff^2/\mu^2 )^Q$. Concerning the next-to-leading order, we show that, while the pure $\mu^2/\cutoff^2 $ corrections cannot be traced back to a finite number of non renormalizable interactions, those of order $(\mu^2/\cutoff^2 ) \ln (\cutoff^2/\mu^2 )$ receive contributions from a finite set of $1/\cutoff^2$ terms. Their presence modifies the behaviour of observable quantities in the intermediate $Q^2$ region. We explicitely discuss their relevance for the two point vector currents Green's function.
[ { "created": "Fri, 21 Jan 1994 18:35:34 GMT", "version": "v1" }, { "created": "Thu, 3 Feb 1994 10:50:00 GMT", "version": "v2" } ]
2009-10-28
[ [ "Pallante", "E.", "" ], [ "Petronzio", "R.", "" ] ]
We construct an effective Lagrangian for low energy hadronic interactions through an infinite expansion in inverse powers of the low energy cutoff $\Lambda_\chi$ of all possible chiral invariant non-renormalizable interactions between quarks and mesons degrees of freedom. We restrict our analysis to the leading terms in the $1/N_c$ expansion. The effective expansion is in $(\mu^2/\cutoff^2 )^P \ln (\cutoff^2/\mu^2 )^Q$. Concerning the next-to-leading order, we show that, while the pure $\mu^2/\cutoff^2 $ corrections cannot be traced back to a finite number of non renormalizable interactions, those of order $(\mu^2/\cutoff^2 ) \ln (\cutoff^2/\mu^2 )$ receive contributions from a finite set of $1/\cutoff^2$ terms. Their presence modifies the behaviour of observable quantities in the intermediate $Q^2$ region. We explicitely discuss their relevance for the two point vector currents Green's function.
hep-ph/9207211
null
B.K. Jennings and G.A. Miller
Realistic Hadronic Matrix Element Approach to Color Transparency
12 pages, U.Wa. 40427-24-N92,TRIUMF TR-pp-92-48
Phys.Rev.Lett. 69 (1992) 3619-3622
10.1103/PhysRevLett.69.3619
null
hep-ph
null
Color transparency occurs if a small-sized wave packet, formed in a high momentum transfer process, escapes the nucleus before expanding. The time required for the expansion depends on the masses of the baryonic components of the wave packet. Measured proton diffractive dissociation and electron deep inelastic scattering cross sections are used to examine and severely constrain the relevant masses. These constraints allow significant color transparency effects to occur at experimentally accessible momentum transfers.
[ { "created": "Fri, 3 Jul 1992 15:32:30 GMT", "version": "v1" } ]
2009-10-22
[ [ "Jennings", "B. K.", "" ], [ "Miller", "G. A.", "" ] ]
Color transparency occurs if a small-sized wave packet, formed in a high momentum transfer process, escapes the nucleus before expanding. The time required for the expansion depends on the masses of the baryonic components of the wave packet. Measured proton diffractive dissociation and electron deep inelastic scattering cross sections are used to examine and severely constrain the relevant masses. These constraints allow significant color transparency effects to occur at experimentally accessible momentum transfers.
1403.4107
Hasan Sonmez
Alon E. Faraggi, John Rizos and Hasan Sonmez
Classification of Flipped SU(5) Heterotic-String Vacua
Minor changes (Version 2) - 51 pages - 3 figures - Added acknowledgements
Nucl.Phys.B886:202-242,2014
10.1016/j.nuclphysb.2014.06.025
LTH-999
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the classification of the free fermionic heterotic-string vacua to models in which the SO(10) GUT symmetry at the string scale is broken to the flipped SU(5) subgroup. In our classification method, the set of basis vectors defined by the boundary conditions which are assigned to the free fermions is fixed and the enumeration of the string vacua is obtained in terms of the Generalised GSO (GGSO) projection coefficients entering the one-loop partition function. We derive algebraic expressions for the GGSO projections for all the physical states appearing in the sectors generated by the set of basis vectors. This enables the analysis of the entire string spectrum to be programmed in to a computer code therefore, we performed a statistical sampling in the space of 2^{44} (approximately 10^{13}) flipped $SU(5)$ vacua and scanned up to 10^{12} GGSO configurations. For that purpose, two independent codes were developed based on JAVA and FORTRAN95. All the results presented here are confirmed by the two independent routines. Contrary to the corresponding Pati-Salam classification, we do not find exophobic flipped SU(5) vacua with an odd number of generations. We study the structure of exotic states appearing in the three generation models that additionally contain a viable Higgs spectrum. Moreover, we demonstrate the existence of models in which all the exotic states are confined by a hidden sector non-Abelian gauge symmetry as well as models that may admit the racetrack mechanism.
[ { "created": "Mon, 17 Mar 2014 14:21:15 GMT", "version": "v1" }, { "created": "Mon, 31 Mar 2014 01:57:59 GMT", "version": "v2" } ]
2014-10-01
[ [ "Faraggi", "Alon E.", "" ], [ "Rizos", "John", "" ], [ "Sonmez", "Hasan", "" ] ]
We extend the classification of the free fermionic heterotic-string vacua to models in which the SO(10) GUT symmetry at the string scale is broken to the flipped SU(5) subgroup. In our classification method, the set of basis vectors defined by the boundary conditions which are assigned to the free fermions is fixed and the enumeration of the string vacua is obtained in terms of the Generalised GSO (GGSO) projection coefficients entering the one-loop partition function. We derive algebraic expressions for the GGSO projections for all the physical states appearing in the sectors generated by the set of basis vectors. This enables the analysis of the entire string spectrum to be programmed in to a computer code therefore, we performed a statistical sampling in the space of 2^{44} (approximately 10^{13}) flipped $SU(5)$ vacua and scanned up to 10^{12} GGSO configurations. For that purpose, two independent codes were developed based on JAVA and FORTRAN95. All the results presented here are confirmed by the two independent routines. Contrary to the corresponding Pati-Salam classification, we do not find exophobic flipped SU(5) vacua with an odd number of generations. We study the structure of exotic states appearing in the three generation models that additionally contain a viable Higgs spectrum. Moreover, we demonstrate the existence of models in which all the exotic states are confined by a hidden sector non-Abelian gauge symmetry as well as models that may admit the racetrack mechanism.
1806.08699
A. N. Ivanov
A. N. Ivanov, R. H\"ollwieser, N. I. Troitskaya, M. Wellenzohn, and Ya. A. Berdnikov
Gauge and Infrared Properties of Hadronic Structure of Nucleon in Neutron Beta Decay to Order O(\alpha/\pi) in Standard V - A Effective Theory with QED and Linear Sigma Model of Strong Low--Energy Interactions
9 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:1806.04630 and arXiv:1805.09702
null
10.1142/S0217751X19500106
null
hep-ph gr-qc nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the standard V - A theory of weak interactions, Quantum Electrodynamics (QED) and the linear sigma-model (LsM) of strong low-energy hadronic interactions we analyse gauge and infrared properties of hadronic structure of the neutron and proton in the neutron beta decay to leading order in the large nucleon mass expansion. We show that the complete set of Feynman diagrams describing radiative corrections of order O(\alpha/\pi), induced by hadronic structure of the nucleon, to the rate of the neutron beta decay is gauge non-invariant and unrenormalisable. We show that a gauge non-invariant contribution does not depend on the electron energy in agreement with Sirlin's analysis of contributions of strong low-energy interactions (Phys. Rev. 164, 1767 (1967)). We show that infrared divergent and dependent on the electron energy contributions from the neutron radiative beta decay and neutron beta decay, caused by hadronic structure of the nucleon, are cancelled in the neutron lifetime. Nevertheless, we find that divergent contributions of virtual photon exchanges to the neutron lifetime, induced by hadronic structure of the nucleon, are unrenormalisable even formally. Such an unrenormalizability can be explained by the fact that the effective V - A vertex of hadron-lepton current-current interactions is not a vertex of the combined quantum field theory including QED and LsM, which are renormalizable theories.
[ { "created": "Thu, 21 Jun 2018 13:54:43 GMT", "version": "v1" } ]
2019-02-20
[ [ "Ivanov", "A. N.", "" ], [ "Höllwieser", "R.", "" ], [ "Troitskaya", "N. I.", "" ], [ "Wellenzohn", "M.", "" ], [ "Berdnikov", "Ya. A.", "" ] ]
Within the standard V - A theory of weak interactions, Quantum Electrodynamics (QED) and the linear sigma-model (LsM) of strong low-energy hadronic interactions we analyse gauge and infrared properties of hadronic structure of the neutron and proton in the neutron beta decay to leading order in the large nucleon mass expansion. We show that the complete set of Feynman diagrams describing radiative corrections of order O(\alpha/\pi), induced by hadronic structure of the nucleon, to the rate of the neutron beta decay is gauge non-invariant and unrenormalisable. We show that a gauge non-invariant contribution does not depend on the electron energy in agreement with Sirlin's analysis of contributions of strong low-energy interactions (Phys. Rev. 164, 1767 (1967)). We show that infrared divergent and dependent on the electron energy contributions from the neutron radiative beta decay and neutron beta decay, caused by hadronic structure of the nucleon, are cancelled in the neutron lifetime. Nevertheless, we find that divergent contributions of virtual photon exchanges to the neutron lifetime, induced by hadronic structure of the nucleon, are unrenormalisable even formally. Such an unrenormalizability can be explained by the fact that the effective V - A vertex of hadron-lepton current-current interactions is not a vertex of the combined quantum field theory including QED and LsM, which are renormalizable theories.
1810.05138
Matteo Becchetti
Matteo Becchetti, Roberto Bonciani, Valerio Casconi, Vittorio Del Duca, Francesco Moriello
Planar master integrals for the two-loop light-fermion electroweak corrections to Higgs plus jet production
21 pages, ancillary files
null
10.1007/JHEP12(2018)019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the analytic calculation of the planar master integrals which contribute to compute the two-loop light-fermion electroweak corrections to the production of a Higgs boson in association with a jet in gluon-gluon fusion. The complete dependence on the electroweak-boson mass is retained. The master integrals are evaluated by means of the differential equations method and the analytic results are expressed in terms of multiple polylogarithms up to weight four.
[ { "created": "Thu, 11 Oct 2018 17:38:25 GMT", "version": "v1" } ]
2018-12-26
[ [ "Becchetti", "Matteo", "" ], [ "Bonciani", "Roberto", "" ], [ "Casconi", "Valerio", "" ], [ "Del Duca", "Vittorio", "" ], [ "Moriello", "Francesco", "" ] ]
We present the analytic calculation of the planar master integrals which contribute to compute the two-loop light-fermion electroweak corrections to the production of a Higgs boson in association with a jet in gluon-gluon fusion. The complete dependence on the electroweak-boson mass is retained. The master integrals are evaluated by means of the differential equations method and the analytic results are expressed in terms of multiple polylogarithms up to weight four.
hep-ph/9606465
Laurent Favart
L. Favart, M. Gruw\'e, P. Marage, Z. Zhang
On the possibility of measuring $F_L(x,Q^2)$ at HERA using radiative events
12 pages (6 figures)
Z.Phys. C72 (1996) 425-428
10.1007/BF02909170
LAL 96-32, IIHE 96-01
hep-ph
null
It is shown that a significant measurement of the longitudinal structure function $F_L(x,Q^2)$ can be performed at HERA, for $Q^2 = 2 GeV^2$ and $Q^2 = 5 GeV^2$ and for x around $10^{-4}$, using radiative events with hard photon emission collinear to the incident lepton beam, under the present running conditions and with an integrated luminosity of 10 $pb^{-1}$. The influence of experimental conditions is discussed.
[ { "created": "Fri, 28 Jun 1996 04:28:32 GMT", "version": "v1" } ]
2009-10-28
[ [ "Favart", "L.", "" ], [ "Gruwé", "M.", "" ], [ "Marage", "P.", "" ], [ "Zhang", "Z.", "" ] ]
It is shown that a significant measurement of the longitudinal structure function $F_L(x,Q^2)$ can be performed at HERA, for $Q^2 = 2 GeV^2$ and $Q^2 = 5 GeV^2$ and for x around $10^{-4}$, using radiative events with hard photon emission collinear to the incident lepton beam, under the present running conditions and with an integrated luminosity of 10 $pb^{-1}$. The influence of experimental conditions is discussed.
hep-ph/0211410
Yu. A. Simonov
Yu.A. Simonov (ITEP, Moscow)
Nonperturbative mechanisms of strong decays in QCD
12 pages, latex2e
Phys.Atom.Nucl. 66 (2003) 2045-2050; Yad.Fiz. 66 (2003) 2095-2100
10.1134/1.1625747
null
hep-ph
null
Three decay mechanisms are derived systematically from the QCD Lagrangian using the field correlator method. Resulting operators contain no arbitrary parameters and depend only on characteristics of field correlators known from lattice and analytic calculations. When compared to existing phenomenological models, parameters are in good agreement with the corresponding fitted values.
[ { "created": "Tue, 26 Nov 2002 15:26:28 GMT", "version": "v1" } ]
2009-11-07
[ [ "Simonov", "Yu. A.", "", "ITEP, Moscow" ] ]
Three decay mechanisms are derived systematically from the QCD Lagrangian using the field correlator method. Resulting operators contain no arbitrary parameters and depend only on characteristics of field correlators known from lattice and analytic calculations. When compared to existing phenomenological models, parameters are in good agreement with the corresponding fitted values.
hep-ph/0209373
Heinrich Paes
H. P\"as (W\"urzburg), L. Song, T.J. Weiler (Vanderbilt)
The hidden sterile neutrino and the (2+2) sum rule
43 pages, 11 figures (same as v2, accidental replacement)
Phys.Rev. D67 (2003) 073019
10.1103/PhysRevD.67.073019
WUE-ITP-2002-026
hep-ph
null
We discuss oscillations of atmospheric and solar neutrinos into sterile neutrinos in the 2+2 scheme. A zeroth order sum rule requires equal probabilities for oscillation into nu_s and nu_tau in the solar+atmospheric data sample. Data does not favor this claim. Here we use scatter plots to assess corrections of the zeroth order sum rule when (i) the 4 x 4 neutrino mixing matrix assumes its full range of allowed values, and (ii) matter effects are included. We also introduce a related "product rule". We find that the sum rule is significantly relaxed, due to both the inclusion of the small mixing angles (which provide a short-baseline contribution) and to matter effects. The product rule is also dramatically altered. The observed relaxation of the sum rule weakens the case against the 2+2 model and the sterile neutrino. To invalidate the 2+2 model, a global fit to data with the small mixing angles included seems to be required.
[ { "created": "Mon, 30 Sep 2002 16:10:55 GMT", "version": "v1" }, { "created": "Mon, 25 Nov 2002 20:33:29 GMT", "version": "v2" }, { "created": "Wed, 23 Apr 2003 14:00:59 GMT", "version": "v3" } ]
2009-11-07
[ [ "Päs", "H.", "", "Würzburg" ], [ "Song", "L.", "", "Vanderbilt" ], [ "Weiler", "T. J.", "", "Vanderbilt" ] ]
We discuss oscillations of atmospheric and solar neutrinos into sterile neutrinos in the 2+2 scheme. A zeroth order sum rule requires equal probabilities for oscillation into nu_s and nu_tau in the solar+atmospheric data sample. Data does not favor this claim. Here we use scatter plots to assess corrections of the zeroth order sum rule when (i) the 4 x 4 neutrino mixing matrix assumes its full range of allowed values, and (ii) matter effects are included. We also introduce a related "product rule". We find that the sum rule is significantly relaxed, due to both the inclusion of the small mixing angles (which provide a short-baseline contribution) and to matter effects. The product rule is also dramatically altered. The observed relaxation of the sum rule weakens the case against the 2+2 model and the sterile neutrino. To invalidate the 2+2 model, a global fit to data with the small mixing angles included seems to be required.
hep-ph/0502124
Toshihiko Ota
Toshihiko Ota and Joe Sato
Signature of the Minimal Supersymmetric Standard Model with Right-Handed Neutrinos in Long Baseline Experiments
29 pages, 6 eps files
Phys.Rev. D71 (2005) 096004
10.1103/PhysRevD.71.096004
OU-HET-517, STUPP-05-179, TUM-HEP-574/05
hep-ph
null
The effective interactions which violate a lepton flavor accompanied with neutrinos (nLFV) are considered. Such a new physics effect is expected to be measured in future neutrino oscillation experiments with long baseline. They are induced by radiative correction in the framework of the minimal supersymmetric standard model with right-handed neutrinos. We numerically evaluate the size of the couplings for nLFV interactions in this framework. The slepton mixing is not only the origin of the lepton flavor violation in the charged lepton sector (cLFV) but also that of the nLFV. We find that the nLFV couplings are strongly correlated with the corresponding cLFV process, and they are constrained at $\mathcal{O}(10^{-5})$ times smaller than the standard four-Fermi couplings.
[ { "created": "Mon, 14 Feb 2005 10:54:26 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ota", "Toshihiko", "" ], [ "Sato", "Joe", "" ] ]
The effective interactions which violate a lepton flavor accompanied with neutrinos (nLFV) are considered. Such a new physics effect is expected to be measured in future neutrino oscillation experiments with long baseline. They are induced by radiative correction in the framework of the minimal supersymmetric standard model with right-handed neutrinos. We numerically evaluate the size of the couplings for nLFV interactions in this framework. The slepton mixing is not only the origin of the lepton flavor violation in the charged lepton sector (cLFV) but also that of the nLFV. We find that the nLFV couplings are strongly correlated with the corresponding cLFV process, and they are constrained at $\mathcal{O}(10^{-5})$ times smaller than the standard four-Fermi couplings.
hep-ph/9802440
Yuri V. Kovchegov
Yuri V. Kovchegov, A.H. Mueller (Columbia University)
Gluon production in current-nucleus and nucleon-nucleus collisions in a quasi-classical approximation
LaTeX, 29 pages, 19 figures
Nucl.Phys.B529:451-479,1998
10.1016/S0550-3213(98)00384-8
CU-TP-876
hep-ph
null
We calculate gluon production in deep inelastic scattering of the current j= - (1/4) F_{\mu\nu}^a F_{\mu\nu}^a off a large nucleus and in nucleon-nucleus collisions. In a covariant gauge calculation the transverse momentum spectrum of the gluon is determined by the final state interactions of the gluon with the nucleons in the nucleus. In a light-cone gauge calculation final state interactions are absent and these effects come from the light-cone wavefunction of the nucleus. We work in an approximation which neglects QCD evolution of gluons in the nucleon, that is in a quasi-classical approximation.
[ { "created": "Thu, 26 Feb 1998 19:17:47 GMT", "version": "v1" } ]
2011-08-11
[ [ "Kovchegov", "Yuri V.", "", "Columbia University" ], [ "Mueller", "A. H.", "", "Columbia University" ] ]
We calculate gluon production in deep inelastic scattering of the current j= - (1/4) F_{\mu\nu}^a F_{\mu\nu}^a off a large nucleus and in nucleon-nucleus collisions. In a covariant gauge calculation the transverse momentum spectrum of the gluon is determined by the final state interactions of the gluon with the nucleons in the nucleus. In a light-cone gauge calculation final state interactions are absent and these effects come from the light-cone wavefunction of the nucleus. We work in an approximation which neglects QCD evolution of gluons in the nucleon, that is in a quasi-classical approximation.
hep-ph/0201080
Gabriela Barenboim
G.Barenboim, L.Borissov and J.Lykken
Neutrinos that violate CPT, and the experiments that love them
17 pages, 3 eps figures
Phys.Lett.B534:106-113,2002
10.1016/S0370-2693(02)01597-6
null
hep-ph
null
Recently we proposed a framework for explaining the observed evidence for neutrino oscillations without enlarging the neutrino sector, by introducing CPT violating Dirac masses for the neutrinos. In this paper we continue the exploration of the phenomenology of CPT violation in the neutrino sector. We show that our CPT violating model fits the existing SuperKamiokande data at least as well as the standard atmospheric neutrino oscillation models. We discuss the challenge of measuring CP violation in a neutrino sector that also violates CPT. We point out that the proposed off-axis extension of MINOS looks especially promising in this regard. Finally, we describe a method to compute CPT violating neutrino effects by mocking them up with analog matter effects.
[ { "created": "Thu, 10 Jan 2002 19:52:33 GMT", "version": "v1" } ]
2015-06-25
[ [ "Barenboim", "G.", "" ], [ "Borissov", "L.", "" ], [ "Lykken", "J.", "" ] ]
Recently we proposed a framework for explaining the observed evidence for neutrino oscillations without enlarging the neutrino sector, by introducing CPT violating Dirac masses for the neutrinos. In this paper we continue the exploration of the phenomenology of CPT violation in the neutrino sector. We show that our CPT violating model fits the existing SuperKamiokande data at least as well as the standard atmospheric neutrino oscillation models. We discuss the challenge of measuring CP violation in a neutrino sector that also violates CPT. We point out that the proposed off-axis extension of MINOS looks especially promising in this regard. Finally, we describe a method to compute CPT violating neutrino effects by mocking them up with analog matter effects.
hep-ph/9602305
Martin Hirsch
M. Hirsch, H.V. Klapdor-Kleingrothaus and S.G. Kovalenko
New Low-energy Leptoquark Interactions
LaTeX, 9 pages, no figures
Phys.Lett. B378 (1996) 17-22
10.1016/0370-2693(96)00419-4
null
hep-ph
null
We discuss an extension of the standard model (SM) with vector and scalar leptoquarks. The renormalizable leptoquark Lagrangian consistent with the SM gauge symmetry is presented including the leptoquark-Higgs interactions previously not considered in the literature. We discuss the importance of these new interactions for leptoquark phenomenology. After the electro-weak symmetry breaking they generate non-trivial leptoquark mass matrices. These lead to mixing between different $SU(2)_L$-multiplets of the leptoquarks and induce at low energies new effective 4-fermion lepton-quark vertices. The latter affect the standard leptoquark phenomenology. We discuss constraints on these interactions from the helicity-suppressed $\pi\rightarrow \nu + e$ decay.
[ { "created": "Wed, 14 Feb 1996 12:04:41 GMT", "version": "v1" } ]
2009-10-28
[ [ "Hirsch", "M.", "" ], [ "Klapdor-Kleingrothaus", "H. V.", "" ], [ "Kovalenko", "S. G.", "" ] ]
We discuss an extension of the standard model (SM) with vector and scalar leptoquarks. The renormalizable leptoquark Lagrangian consistent with the SM gauge symmetry is presented including the leptoquark-Higgs interactions previously not considered in the literature. We discuss the importance of these new interactions for leptoquark phenomenology. After the electro-weak symmetry breaking they generate non-trivial leptoquark mass matrices. These lead to mixing between different $SU(2)_L$-multiplets of the leptoquarks and induce at low energies new effective 4-fermion lepton-quark vertices. The latter affect the standard leptoquark phenomenology. We discuss constraints on these interactions from the helicity-suppressed $\pi\rightarrow \nu + e$ decay.
2201.01151
Fabio Dogliotti
Aldo Deandrea, Fabio Dogliotti, Dimitrios Tsimpis
Gauge-Higgs models from Nilmanifolds
8 pages, 1 figure
null
10.1016/j.physletb.2022.137097
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the compactification of a Yang-Mills theory on a three-dimensional nilmanifold. The compactification generates a Yang-Mills theory in four space-time dimensions, coupled to a specific scalar sector. The compactification geometry gives rise to masses for the zero-modes, proportional to the twist parameter of the nilmanifold. We study the simple example of an SU (3) model broken by a non-trivial vacuum of the scalar potential which generates three mass scales, two being at tree level, and the third one at loop level. We point out the relevance of general twisted geometries for model building and in particular for gauge-Higgs type models, as the twist generates tree-level mass hierarchies useful for grand unification and for the Higgs sector in electroweak symmetry breaking.
[ { "created": "Tue, 4 Jan 2022 14:24:10 GMT", "version": "v1" }, { "created": "Mon, 11 Apr 2022 11:53:25 GMT", "version": "v2" } ]
2022-04-20
[ [ "Deandrea", "Aldo", "" ], [ "Dogliotti", "Fabio", "" ], [ "Tsimpis", "Dimitrios", "" ] ]
We consider the compactification of a Yang-Mills theory on a three-dimensional nilmanifold. The compactification generates a Yang-Mills theory in four space-time dimensions, coupled to a specific scalar sector. The compactification geometry gives rise to masses for the zero-modes, proportional to the twist parameter of the nilmanifold. We study the simple example of an SU (3) model broken by a non-trivial vacuum of the scalar potential which generates three mass scales, two being at tree level, and the third one at loop level. We point out the relevance of general twisted geometries for model building and in particular for gauge-Higgs type models, as the twist generates tree-level mass hierarchies useful for grand unification and for the Higgs sector in electroweak symmetry breaking.
1007.1972
Aleksey Cherman
Paulo F. Bedaque, Michael I. Buchoff, Aleksey Cherman
The phases of deuterium at extreme densities
9 pages, 6 figures; v2: fixed typos
JHEP 1104:094,2011
10.1007/JHEP04(2011)094
UMD-40762-482
hep-ph astro-ph.EP cond-mat.supr-con hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider deuterium compressed to higher than atomic, but lower than nuclear densities. At such densities deuterium is a superconducting quantum liquid. Generically, two superconducting phases compete, a "ferromagnetic" and a "nematic" one. We provide a power counting argument suggesting that the dominant interactions in the deuteron liquid are perturbative (but screened) Coulomb interactions. At very high densities the ground state is determined by very small nuclear interaction effects that probably favor the ferromagnetic phase. At lower densities the symmetry of the theory is effectively enhanced to SU(3), and the quantum liquid enters a novel phase, neither ferromagnetic nor nematic. Our results can serve as a starting point for investigations of the phase dynamics of deuteron liquids, as well as exploration of the stability and dynamics of the rich variety of topological objects that may occur in phases of the deuteron quantum liquid, which range from Alice strings to spin skyrmions to Z_2 vortices.
[ { "created": "Mon, 12 Jul 2010 20:00:15 GMT", "version": "v1" }, { "created": "Sun, 1 Aug 2010 16:45:23 GMT", "version": "v2" } ]
2011-05-09
[ [ "Bedaque", "Paulo F.", "" ], [ "Buchoff", "Michael I.", "" ], [ "Cherman", "Aleksey", "" ] ]
We consider deuterium compressed to higher than atomic, but lower than nuclear densities. At such densities deuterium is a superconducting quantum liquid. Generically, two superconducting phases compete, a "ferromagnetic" and a "nematic" one. We provide a power counting argument suggesting that the dominant interactions in the deuteron liquid are perturbative (but screened) Coulomb interactions. At very high densities the ground state is determined by very small nuclear interaction effects that probably favor the ferromagnetic phase. At lower densities the symmetry of the theory is effectively enhanced to SU(3), and the quantum liquid enters a novel phase, neither ferromagnetic nor nematic. Our results can serve as a starting point for investigations of the phase dynamics of deuteron liquids, as well as exploration of the stability and dynamics of the rich variety of topological objects that may occur in phases of the deuteron quantum liquid, which range from Alice strings to spin skyrmions to Z_2 vortices.
1408.0011
Daniel Whiteson
Ning Zhou, Zepyoor Khechadoorian, Daniel Whiteson, Tim Tait
Erratum: Bounds on Invisible Higgs boson Decays from $t\bar{t}H$ Production
Erratum, replacement of earlier paper
null
10.1103/PhysRevLett.113.151801
UCI-HEP-TR-2014-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bounds on invisible decays of the Higgs boson from $t\bar{t}H$ production were inferred from a CMS search for stop quarks decaying to $t\bar{t}$ and missing transverse momentum. Limits on the production of $t\bar{t}H$ relied on the efficiency of the CMS selection for $t\bar{t}H$, as measured in a simulated sample. An error in the generation of the simulated sample lead to a significant overestimate of the selection efficiency. Corrected results are presented.
[ { "created": "Thu, 31 Jul 2014 20:00:23 GMT", "version": "v1" }, { "created": "Fri, 17 Apr 2015 16:57:29 GMT", "version": "v2" } ]
2015-06-22
[ [ "Zhou", "Ning", "" ], [ "Khechadoorian", "Zepyoor", "" ], [ "Whiteson", "Daniel", "" ], [ "Tait", "Tim", "" ] ]
Bounds on invisible decays of the Higgs boson from $t\bar{t}H$ production were inferred from a CMS search for stop quarks decaying to $t\bar{t}$ and missing transverse momentum. Limits on the production of $t\bar{t}H$ relied on the efficiency of the CMS selection for $t\bar{t}H$, as measured in a simulated sample. An error in the generation of the simulated sample lead to a significant overestimate of the selection efficiency. Corrected results are presented.
hep-ph/0407147
Joan Rojo
Joan Rojo
A probability measure in the space of spectral functions and structure functions
4pp. Talk given at 11th International QCD Conference (QCD 04), Montpellier, France, 5-9 Jul 2004
null
null
UB-ECM-PF-04-17
hep-ph
null
We present a novel technique to parametrize experimental data, based on the construction of a probability measure in the space of functions, which retains the full experimental information on errors and correlations. This measure is constructed in a two step process: first, a Monte Carlo sample of replicas of the experimental data is generated, and then an ensemble of neural network is trained over them. This parametrization does not introduce any bias due to the choice of a fixed functional form. Two applications of this technique are presented. First a probability measure in the space of the spectral function $\rho_{V-A}(s)$ is generated, which incorporates theoretical constraints as chiral sum rules, and is used to evaluate the vacuum condensates. Then we construct a probability measure in the space of the proton structure function $F_2^p(x,Q^2)$, which updates previous work, incorporating HERA data.
[ { "created": "Tue, 13 Jul 2004 10:31:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rojo", "Joan", "" ] ]
We present a novel technique to parametrize experimental data, based on the construction of a probability measure in the space of functions, which retains the full experimental information on errors and correlations. This measure is constructed in a two step process: first, a Monte Carlo sample of replicas of the experimental data is generated, and then an ensemble of neural network is trained over them. This parametrization does not introduce any bias due to the choice of a fixed functional form. Two applications of this technique are presented. First a probability measure in the space of the spectral function $\rho_{V-A}(s)$ is generated, which incorporates theoretical constraints as chiral sum rules, and is used to evaluate the vacuum condensates. Then we construct a probability measure in the space of the proton structure function $F_2^p(x,Q^2)$, which updates previous work, incorporating HERA data.
1904.08172
Ralf-Arno Tripolt
Daniele Binosi, Ralf-Arno Tripolt
Spectral functions of confined particles
7 pages, 5 figures. Extended version which includes the analysis of lattice unquenched 2+1+1 Landau gauge data and quenched Rxi gauge data. Matches the published version in PLB
null
10.1016/j.physletb.2019.135171
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the gluon and ghost spectral functions along with the analytic structure of the associated propagators from numerical data describing gauge correlators at space-like momenta obtained by either solving the Dyson-Schwinger equations or through lattice simulations. Our novel reconstruction technique shows the expected branch cut for the gluon and the ghost propagator, which, in the gluon case, is supplemented with a pair of complex conjugate poles. Possible implications of the existence of these poles are briefly addressed.
[ { "created": "Wed, 17 Apr 2019 10:35:28 GMT", "version": "v1" }, { "created": "Fri, 10 Jan 2020 09:40:17 GMT", "version": "v2" }, { "created": "Fri, 28 Feb 2020 14:02:52 GMT", "version": "v3" } ]
2020-03-02
[ [ "Binosi", "Daniele", "" ], [ "Tripolt", "Ralf-Arno", "" ] ]
We determine the gluon and ghost spectral functions along with the analytic structure of the associated propagators from numerical data describing gauge correlators at space-like momenta obtained by either solving the Dyson-Schwinger equations or through lattice simulations. Our novel reconstruction technique shows the expected branch cut for the gluon and the ghost propagator, which, in the gluon case, is supplemented with a pair of complex conjugate poles. Possible implications of the existence of these poles are briefly addressed.
hep-ph/9909520
York Schroeder
Y. Schroder
The Two-Loop Static Potential
4 pages, LaTeX, 1 figure. Invited talk given at at QCD Euroconference 99, Montpellier, 7-13 July 1999
Nucl.Phys.Proc.Suppl. 86 (2000) 525-528
10.1016/S0920-5632(00)00616-2
DESY 99-147
hep-ph
null
In quantum chromodynamics (QCD), the binding energy of an infinitely heavy quark--antiquark pair in a color singlet state can be calculated as a function of the distance. We investigate this static potential of QCD perturbatively and calculate the full two-loop coefficient, correcting an earlier result. Beyond this order, the perturbative expansion breaks down.
[ { "created": "Mon, 27 Sep 1999 12:41:30 GMT", "version": "v1" } ]
2009-10-31
[ [ "Schroder", "Y.", "" ] ]
In quantum chromodynamics (QCD), the binding energy of an infinitely heavy quark--antiquark pair in a color singlet state can be calculated as a function of the distance. We investigate this static potential of QCD perturbatively and calculate the full two-loop coefficient, correcting an earlier result. Beyond this order, the perturbative expansion breaks down.
1904.10432
Diptimoy Ghosh
Debjyoti Bardhan, Diptimoy Ghosh
B-meson charged current anomalies: the post-Moriond status
Version to be published in Phys. Rev. D, Rapid Communications
Phys. Rev. D 100, 011701 (2019)
10.1103/PhysRevD.100.011701
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note, we discuss the impact of the recent Belle result on the various theoretical explanations of the $R_D$ and $R_{D^*}$ anomalies. The pure tensor explanation, which was strongly disfavoured by the measurements of $F_L^{D^*}$ and high-$p_T$ $p \, p \to \tau \, \nu$ searches before Moriond, is now completely allowed because of reduction of the experimental world-average. Moreover, the pure right-chiral vector solution (involving right-chiral neutrinos) has now moved into the $2\sigma$ allowed range of the LHC $p \, p \to \tau \, \nu$ searches. We also critically re-examine the bound on $\mathcal{B}(B_c^- \to \tau^- \bar{\nu}_\tau)$ from LEP data and show that the bound is considerably weaker than the number $10\%$ often used in the recent literature.
[ { "created": "Tue, 23 Apr 2019 17:27:00 GMT", "version": "v1" }, { "created": "Mon, 6 May 2019 16:12:54 GMT", "version": "v2" }, { "created": "Mon, 17 Jun 2019 07:57:57 GMT", "version": "v3" } ]
2019-07-17
[ [ "Bardhan", "Debjyoti", "" ], [ "Ghosh", "Diptimoy", "" ] ]
In this note, we discuss the impact of the recent Belle result on the various theoretical explanations of the $R_D$ and $R_{D^*}$ anomalies. The pure tensor explanation, which was strongly disfavoured by the measurements of $F_L^{D^*}$ and high-$p_T$ $p \, p \to \tau \, \nu$ searches before Moriond, is now completely allowed because of reduction of the experimental world-average. Moreover, the pure right-chiral vector solution (involving right-chiral neutrinos) has now moved into the $2\sigma$ allowed range of the LHC $p \, p \to \tau \, \nu$ searches. We also critically re-examine the bound on $\mathcal{B}(B_c^- \to \tau^- \bar{\nu}_\tau)$ from LEP data and show that the bound is considerably weaker than the number $10\%$ often used in the recent literature.
2306.07446
Luciano Abreu
A. L. M. Britto, L. M. Abreu and F. S. Navarra
Interactions of the $\chi_{c1}(4274)$ state with light mesons
9 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the interactions of the $\chi_{c1}(4274)$ state with light mesons in the hot hadron gas formed in heavy ion collisions. The vacuum and thermally-averaged cross sections of production of $\chi_{c1}(4274)$ accompanied by light pseudoscalar and light vector mesons as well as the corresponding inverse processes are estimated within the context of an effective Lagrangian approach. The results suggest non-negligible thermal cross-sections, with larger magnitudes for most of the suppression reactions than those for production. This might be a relevant feature to be considered in the analysis of future data collected in heavy ion collisions.
[ { "created": "Mon, 12 Jun 2023 22:26:32 GMT", "version": "v1" } ]
2023-06-14
[ [ "Britto", "A. L. M.", "" ], [ "Abreu", "L. M.", "" ], [ "Navarra", "F. S.", "" ] ]
We investigate the interactions of the $\chi_{c1}(4274)$ state with light mesons in the hot hadron gas formed in heavy ion collisions. The vacuum and thermally-averaged cross sections of production of $\chi_{c1}(4274)$ accompanied by light pseudoscalar and light vector mesons as well as the corresponding inverse processes are estimated within the context of an effective Lagrangian approach. The results suggest non-negligible thermal cross-sections, with larger magnitudes for most of the suppression reactions than those for production. This might be a relevant feature to be considered in the analysis of future data collected in heavy ion collisions.
1507.08614
Martina Gerbino
Martina Gerbino, Massimiliano Lattanzi, Alessandro Melchiorri
The $\nu$ generation: present and future constraints on neutrino masses from cosmology and laboratory experiments
v2: 6 pages, 3 figures, 1 table; added definition of parameter minimal value from oscillation measurements; corrected confidence interval, that in v1 were reported at 90% C.L. and misidentified as 95% C.L.; accepted for publication
Phys. Rev. D 93, 033001 (2016)
10.1103/PhysRevD.93.033001
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a joint analysis of current data from cosmology and laboratory experiments to constrain the neutrino mass parameters in the framework of bayesian statistics, also accounting for uncertainties in nuclear modeling, relevant for neutrinoless double $\beta$ decay ($0\nu2\beta$) searches. We find that a combination of current oscillation, cosmological and $0\nu2\beta$ data constrains $m_{\beta\beta}~<~0.045\,\mathrm{eV}$ ($0.014 \, \mathrm{eV} < m_{\beta\beta} < 0.066 \,\mathrm{eV}$) at 95\% C.L. for normal (inverted) hierarchy. This result is in practice dominated by the cosmological and oscillation data, so it is not affected by uncertainties related to the interpretation of $0\nu2\beta$ data, like nuclear modeling, or the exact particle physics mechanism underlying the process. We then perform forecasts for forthcoming and next-generation experiments, and find that in the case of normal hierarchy, given a total mass of $0.1\,$ eV, and assuming a factor-of-two uncertainty in the modeling of the relevant nuclear matrix elements, it will be possible to measure the total mass itself, the effective Majorana mass and the effective electron mass with an accuracy (at 95\% C.L.) of $0.05$, $0.015$, $0.02\,\mathrm{eV}$ respectively, as well as to be sensitive to one of the Majorana phases. This assumes that neutrinos are Majorana particles and that the mass mechanism gives the dominant contribution to $0\nu2\beta$ decay. We argue that more precise nuclear modeling will be crucial to improve these sensitivities.
[ { "created": "Thu, 30 Jul 2015 18:25:09 GMT", "version": "v1" }, { "created": "Fri, 22 Jan 2016 16:36:33 GMT", "version": "v2" } ]
2016-02-10
[ [ "Gerbino", "Martina", "" ], [ "Lattanzi", "Massimiliano", "" ], [ "Melchiorri", "Alessandro", "" ] ]
We perform a joint analysis of current data from cosmology and laboratory experiments to constrain the neutrino mass parameters in the framework of bayesian statistics, also accounting for uncertainties in nuclear modeling, relevant for neutrinoless double $\beta$ decay ($0\nu2\beta$) searches. We find that a combination of current oscillation, cosmological and $0\nu2\beta$ data constrains $m_{\beta\beta}~<~0.045\,\mathrm{eV}$ ($0.014 \, \mathrm{eV} < m_{\beta\beta} < 0.066 \,\mathrm{eV}$) at 95\% C.L. for normal (inverted) hierarchy. This result is in practice dominated by the cosmological and oscillation data, so it is not affected by uncertainties related to the interpretation of $0\nu2\beta$ data, like nuclear modeling, or the exact particle physics mechanism underlying the process. We then perform forecasts for forthcoming and next-generation experiments, and find that in the case of normal hierarchy, given a total mass of $0.1\,$ eV, and assuming a factor-of-two uncertainty in the modeling of the relevant nuclear matrix elements, it will be possible to measure the total mass itself, the effective Majorana mass and the effective electron mass with an accuracy (at 95\% C.L.) of $0.05$, $0.015$, $0.02\,\mathrm{eV}$ respectively, as well as to be sensitive to one of the Majorana phases. This assumes that neutrinos are Majorana particles and that the mass mechanism gives the dominant contribution to $0\nu2\beta$ decay. We argue that more precise nuclear modeling will be crucial to improve these sensitivities.
1511.03437
Zenro Hioki
Zenro Hioki (U. Tokushima) and Kazumasa Ohkuma (Okayama U. Science)
Full analysis of general non-standard tbW couplings
One comment and two related references added. Final version to appear in Phys.Lett.B
Physics Letters B752 (2016) 128
10.1016/j.physletb.2015.11.029
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Possible non-standard couplings which could contribute to the t -> b W process are studied based on the effective-Lagrangian approach. The corresponding effective Lagrangian consists of four kinds of dimension-6 effective operators, each of which has an independent coupling constant. In this analysis, all those couplings are treated as complex numbers and constraints on them are estimated by using recent experimental data from the LHC. We point out that the resultant constraints on those couplings are still not that strong because contributions from some couplings can work oppositely with each other.
[ { "created": "Wed, 11 Nov 2015 10:08:34 GMT", "version": "v1" }, { "created": "Tue, 17 Nov 2015 03:09:02 GMT", "version": "v2" } ]
2015-11-24
[ [ "Hioki", "Zenro", "", "U. Tokushima" ], [ "Ohkuma", "Kazumasa", "", "Okayama U. Science" ] ]
Possible non-standard couplings which could contribute to the t -> b W process are studied based on the effective-Lagrangian approach. The corresponding effective Lagrangian consists of four kinds of dimension-6 effective operators, each of which has an independent coupling constant. In this analysis, all those couplings are treated as complex numbers and constraints on them are estimated by using recent experimental data from the LHC. We point out that the resultant constraints on those couplings are still not that strong because contributions from some couplings can work oppositely with each other.
hep-ph/0310368
Damien A. Easson
K.R.S. Balaji (McGill U.), Robert H. Brandenberger (Brown U.) and Damien A. Easson (Syracuse U.)
Spectral Dependence of CMB Polarization and Parity
6 pages; Uses REVTeX 4; reference added; version to appear in JCAP
JCAP 0312 (2003) 008
10.1088/1475-7516/2003/12/008
BROWN-HET-1380, MCGILL-22-03, SU-GP-03/10-2
hep-ph astro-ph gr-qc hep-th
null
The polarization of the cosmic microwave background radiation (CMBR) can serve as a probe for nonstandard parity violating interactions. Many such interactions are predicted in particle physics models arising from theories with extra dimensions such as superstring theory. These interactions produce an optical activity that depends on the space-time nature of the parity violating field. In particular, it is possible to obtain a frequency-dependent differential rotation of the polarization axis. The form of the frequency dependence is sensitive to the time evolution of the parity odd background field. Thus, one may be able to study a broad class of parity violating operators through polarization measurements of the CMBR.
[ { "created": "Fri, 31 Oct 2003 20:00:11 GMT", "version": "v1" }, { "created": "Fri, 21 Nov 2003 21:36:01 GMT", "version": "v2" } ]
2007-05-23
[ [ "Balaji", "K. R. S.", "", "McGill U." ], [ "Brandenberger", "Robert H.", "", "Brown U." ], [ "Easson", "Damien A.", "", "Syracuse U." ] ]
The polarization of the cosmic microwave background radiation (CMBR) can serve as a probe for nonstandard parity violating interactions. Many such interactions are predicted in particle physics models arising from theories with extra dimensions such as superstring theory. These interactions produce an optical activity that depends on the space-time nature of the parity violating field. In particular, it is possible to obtain a frequency-dependent differential rotation of the polarization axis. The form of the frequency dependence is sensitive to the time evolution of the parity odd background field. Thus, one may be able to study a broad class of parity violating operators through polarization measurements of the CMBR.
hep-ph/0206225
Ibigi
I.I. Bigi
The Vietri Codices
23 pages, no figures, LATEX, final version of Summary Talk given at {\em HQ&L 2002}, International Workshop on Heavy Quarks and Leptons, Vietri sul Mare, Salerno, Italy, May 27 - June 1, 2002. Typos corrected, numbers updated and more praise of hadronization added
Frascati Phys.Ser. 28 (2002) 499-520
null
null
hep-ph
null
Studying heavy flavour physics is driven by multiple motivations: to probe our theoretical control over QCD; enhance our information on gluon and sea quark structure functions; use heavy flavour production as signal for the onset of the quark-gluon plasma; revisit light flavour spectroscopy through the final states in heavy flavour decays; extract fundamental quantities like CKM and MNS parameters; search for new Physics. The last two years have witnessed tremendous amplification in our knowledge of heavy flavour dynamics. We know the elements of the CKM matrix with significantly improved reliability; a new door has been opened by the observation of K^+ --> pi^+ nu nu-bar; with direct CP violation being established in K_L decays and the expected huge CP asymmetry been observed in B_d(t) --> psi K_S the CKM description has attained the level of a tested theory of CP violation. Yet more than ever the Standard Model is viewed as incomplete: apart from the peculiar pattern in mass related parameters of the fundamental fermions there is more direct evidence in the signals for neutrino oscillations, the strong CP problem and the baryon number of the universe. A worldwide, interrelated and comprehensive program has been developed for heavy quark and lepton physics that will provide essential impetus towards a deeper understanding of nature's grand design.
[ { "created": "Sun, 23 Jun 2002 19:05:25 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2002 20:21:58 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bigi", "I. I.", "" ] ]
Studying heavy flavour physics is driven by multiple motivations: to probe our theoretical control over QCD; enhance our information on gluon and sea quark structure functions; use heavy flavour production as signal for the onset of the quark-gluon plasma; revisit light flavour spectroscopy through the final states in heavy flavour decays; extract fundamental quantities like CKM and MNS parameters; search for new Physics. The last two years have witnessed tremendous amplification in our knowledge of heavy flavour dynamics. We know the elements of the CKM matrix with significantly improved reliability; a new door has been opened by the observation of K^+ --> pi^+ nu nu-bar; with direct CP violation being established in K_L decays and the expected huge CP asymmetry been observed in B_d(t) --> psi K_S the CKM description has attained the level of a tested theory of CP violation. Yet more than ever the Standard Model is viewed as incomplete: apart from the peculiar pattern in mass related parameters of the fundamental fermions there is more direct evidence in the signals for neutrino oscillations, the strong CP problem and the baryon number of the universe. A worldwide, interrelated and comprehensive program has been developed for heavy quark and lepton physics that will provide essential impetus towards a deeper understanding of nature's grand design.
2209.03968
Andrzej Buras
Andrzej J. Buras
Standard Model Predictions for Rare K and B Decays without New Physics Infection
V5: Modifications due to BELLE II result given in magenta color on pages 9, 16 and 18. New references added
null
10.1140/epjc/s10052-023-11222-6
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model (SM) does not contain by definition any new physics (NP) contributions to any observable but contains four CKM parameters which are not predicted by this model. We point out that if these four parameters are determined in a global fit that includes processes which are infected by NP, the resulting SM contributions to rare decay branching ratios cannot be considered as true SM contributions to the latter. On the other hand true SM predictions, that are free from the CKM dependence, can be obtained for suitable ratios of the $K$ and $B$ rare decay branching ratios to $\Delta M_s$, $\Delta M_d$ and $|\varepsilon_K|$, all calculated within the SM. These three observables contain by now only small hadronic uncertainties and are already well measured so that rather precise true SM predictions for the ratios in question can be obtained. In this context the rapid test of NP infection in the $\Delta F=2$ sector is provided by a $|V_{cb}|-\gamma$ plot that involves $\Delta M_s$, $\Delta M_d$, $|\varepsilon_K|$, and the mixing induced CP-asymmetry $S_{\psi K_S}$. As with the present hadronic matrix elements this test turns out to be negative, assuming negligible NP infection in the $\Delta F=2$ sector and setting the values of these four observables to the experimental ones, allows to obtain SM predictions for all $K$ and $B$ rare decay branching ratios that are most accurate to date and as a byproduct to obtain the full CKM matrix on the basis of $\Delta F=2$ transitions alone. Using this strategy we obtain SM predictions for 26 branching ratios for rare semileptonic and leptonic $K$ and $B$ decays with the $\mu^+\mu^-$ pair or the $\nu\bar\nu$ pair in the final state. Most interesting turn out to be the anomalies in the low $q^2$ bin in $B^+\to K^+\mu^+\mu^-$ ($4.4\sigma$) and $B_s\to \phi\mu^+\mu^-$ ($4.8\sigma$).
[ { "created": "Thu, 8 Sep 2022 18:00:02 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2022 14:37:09 GMT", "version": "v2" }, { "created": "Sun, 5 Feb 2023 21:23:46 GMT", "version": "v3" }, { "created": "Mon, 31 Jul 2023 13:43:05 GMT", "version": "v4" }, { "created": "Thu, 4 Jan 2024 16:53:01 GMT", "version": "v5" } ]
2024-01-05
[ [ "Buras", "Andrzej J.", "" ] ]
The Standard Model (SM) does not contain by definition any new physics (NP) contributions to any observable but contains four CKM parameters which are not predicted by this model. We point out that if these four parameters are determined in a global fit that includes processes which are infected by NP, the resulting SM contributions to rare decay branching ratios cannot be considered as true SM contributions to the latter. On the other hand true SM predictions, that are free from the CKM dependence, can be obtained for suitable ratios of the $K$ and $B$ rare decay branching ratios to $\Delta M_s$, $\Delta M_d$ and $|\varepsilon_K|$, all calculated within the SM. These three observables contain by now only small hadronic uncertainties and are already well measured so that rather precise true SM predictions for the ratios in question can be obtained. In this context the rapid test of NP infection in the $\Delta F=2$ sector is provided by a $|V_{cb}|-\gamma$ plot that involves $\Delta M_s$, $\Delta M_d$, $|\varepsilon_K|$, and the mixing induced CP-asymmetry $S_{\psi K_S}$. As with the present hadronic matrix elements this test turns out to be negative, assuming negligible NP infection in the $\Delta F=2$ sector and setting the values of these four observables to the experimental ones, allows to obtain SM predictions for all $K$ and $B$ rare decay branching ratios that are most accurate to date and as a byproduct to obtain the full CKM matrix on the basis of $\Delta F=2$ transitions alone. Using this strategy we obtain SM predictions for 26 branching ratios for rare semileptonic and leptonic $K$ and $B$ decays with the $\mu^+\mu^-$ pair or the $\nu\bar\nu$ pair in the final state. Most interesting turn out to be the anomalies in the low $q^2$ bin in $B^+\to K^+\mu^+\mu^-$ ($4.4\sigma$) and $B_s\to \phi\mu^+\mu^-$ ($4.8\sigma$).
1708.06961
Qiang Zhao
Si-Run Xue, Hao-Jie Jing, Feng-Kun Guo, and Qiang Zhao
Disentangling the role of the $Y(4260)$ in $e^+e^-\to D^*\bar{D}^*$ and $D_s^*\bar{D}_s^*$ via line shape studies
Revtex, 17 pages, 5 eps figures; Revised version to appear in Phys. Lett. B
null
10.1016/j.physletb.2018.02.027
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Whether the $Y(4260)$ can couple to open charm channels has been a crucial issue for understanding its nature. The available experimental data suggest that the cross section line shapes of exclusive processes in $e^+e^-$ annihilations have nontrivial structures around the mass region of the $Y(4260)$. As part of a series of studies of the $Y(4260)$ as mainly a $\bar{D}D_1(2420)+c.c.$ molecular state, we show that the partial widths of the $Y(4260)$ to the two-body open charm channels of $e^+e^-\to D^*\bar{D}^*$ and $D_s^*\bar{D}_s^*$ are much smaller than that to $\bar{D}D^*\pi+c.c.$. The line shapes measured by the Belle Collaboration for these two channels can be well described by the vector charmonium states $\psi(4040)$, $\psi(4160)$ and $\psi(4415)$ together with the $Y(4260)$. It turns out that the interference of the $Y(4260)$ with the other charmonia produces a dip around 4.22~GeV in the $e^+e^-\to D^*\bar{D}^*$ cross section line shape. The data also show an evidence for the strong coupling of the $Y(4260)$ to the $D\bar D_1(2420)$, in line with the expectation in the hadronic molecular scenario for the $Y(4260)$.
[ { "created": "Wed, 23 Aug 2017 11:34:47 GMT", "version": "v1" }, { "created": "Tue, 13 Feb 2018 08:05:47 GMT", "version": "v2" } ]
2018-04-04
[ [ "Xue", "Si-Run", "" ], [ "Jing", "Hao-Jie", "" ], [ "Guo", "Feng-Kun", "" ], [ "Zhao", "Qiang", "" ] ]
Whether the $Y(4260)$ can couple to open charm channels has been a crucial issue for understanding its nature. The available experimental data suggest that the cross section line shapes of exclusive processes in $e^+e^-$ annihilations have nontrivial structures around the mass region of the $Y(4260)$. As part of a series of studies of the $Y(4260)$ as mainly a $\bar{D}D_1(2420)+c.c.$ molecular state, we show that the partial widths of the $Y(4260)$ to the two-body open charm channels of $e^+e^-\to D^*\bar{D}^*$ and $D_s^*\bar{D}_s^*$ are much smaller than that to $\bar{D}D^*\pi+c.c.$. The line shapes measured by the Belle Collaboration for these two channels can be well described by the vector charmonium states $\psi(4040)$, $\psi(4160)$ and $\psi(4415)$ together with the $Y(4260)$. It turns out that the interference of the $Y(4260)$ with the other charmonia produces a dip around 4.22~GeV in the $e^+e^-\to D^*\bar{D}^*$ cross section line shape. The data also show an evidence for the strong coupling of the $Y(4260)$ to the $D\bar D_1(2420)$, in line with the expectation in the hadronic molecular scenario for the $Y(4260)$.
2105.09020
Sabine Kraml
Sabine Kraml, Andre Lessa, Wolfgang Waltenberger
Artificial proto-modelling with simplified-model results from the LHC
6 pages; contribution to the 2021 QCD session of the 55th Rencontres de Moriond
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a novel approach to identify potential dispersed signals of new physics in the slew of published LHC results. It employs a random walk algorithm to introduce sets of new particles, dubbed "proto-models", which are tested against simplified-model results from ATLAS and CMS searches for new physics by exploiting the SModelS software framework. A combinatorial algorithm identifies the set of analyses and/or signal regions that maximally violates the Standard Model hypothesis, while remaining compatible with the entirety of LHC constraints in our database. Crucial to the method is the ability to construct a reliable likelihood in proto-model space; we explain the various approximations which are needed depending on the information available from the experiments, and how they impact the whole procedure.
[ { "created": "Wed, 19 May 2021 09:36:28 GMT", "version": "v1" } ]
2021-05-20
[ [ "Kraml", "Sabine", "" ], [ "Lessa", "Andre", "" ], [ "Waltenberger", "Wolfgang", "" ] ]
We present a novel approach to identify potential dispersed signals of new physics in the slew of published LHC results. It employs a random walk algorithm to introduce sets of new particles, dubbed "proto-models", which are tested against simplified-model results from ATLAS and CMS searches for new physics by exploiting the SModelS software framework. A combinatorial algorithm identifies the set of analyses and/or signal regions that maximally violates the Standard Model hypothesis, while remaining compatible with the entirety of LHC constraints in our database. Crucial to the method is the ability to construct a reliable likelihood in proto-model space; we explain the various approximations which are needed depending on the information available from the experiments, and how they impact the whole procedure.
hep-ph/0212113
Werner Rodejohann
S. Pascoli, S.T. Petcov, W. Rodejohann
On the Neutrino Mass Spectrum and Neutrinoless Double-Beta Decay
18 pages, 2 figures; the text includes 3 tables; results and conclusions unchanged, the KamLAND data taken into account, correspondingly references changed, text shortened; version submitted for publication
Phys.Lett. B558 (2003) 141-156
10.1016/S0370-2693(03)00275-2
SISSA 89/2002/EP, UCLA/02/TEP/38
hep-ph
null
Assuming 3-nu mixing, neutrino oscillation explanation of the solar and atmospheric neutrino data and of the first KamLAND results, massive Majorana neutrinos and neutrinoless double-beta decay generated only by the (V-A) charged current weak interaction via the exchange of the three Majorana neutrinos, we analyze in detail the possibility of determining the type of the neutrino mass spectrum by measuring of the effective Majorana mass |<m>| in neutrinoless double-beta decay. The three possible types of neutrino mass spectrum are considered: i) normal hierarchical (NH), m1 << m2 << m3, ii) inverted hierarchical (IH), m1 << m2 \simeq m3, and iii) quasi-degenerate (QD), m1 \simeq m2 \simeq m3 \geq 0.20 eV. The uncertainty in the measured value of |<m>| due to the imprecise knowledge of the relevant nuclear matrix elements is taken into account in the analysis. We derive the ranges of values of tan^2 theta_\odot, theta_\odot being the mixing angle which controls the solar neutrino oscillations, and of the nuclear matrix element uncertainty factor, for which the measurement of |<m>| would allow one to discriminate between the NH and IH, NH and QD and IH and QD spectra.
[ { "created": "Sun, 8 Dec 2002 13:37:18 GMT", "version": "v1" }, { "created": "Sat, 28 Dec 2002 17:27:47 GMT", "version": "v2" } ]
2010-04-05
[ [ "Pascoli", "S.", "" ], [ "Petcov", "S. T.", "" ], [ "Rodejohann", "W.", "" ] ]
Assuming 3-nu mixing, neutrino oscillation explanation of the solar and atmospheric neutrino data and of the first KamLAND results, massive Majorana neutrinos and neutrinoless double-beta decay generated only by the (V-A) charged current weak interaction via the exchange of the three Majorana neutrinos, we analyze in detail the possibility of determining the type of the neutrino mass spectrum by measuring of the effective Majorana mass |<m>| in neutrinoless double-beta decay. The three possible types of neutrino mass spectrum are considered: i) normal hierarchical (NH), m1 << m2 << m3, ii) inverted hierarchical (IH), m1 << m2 \simeq m3, and iii) quasi-degenerate (QD), m1 \simeq m2 \simeq m3 \geq 0.20 eV. The uncertainty in the measured value of |<m>| due to the imprecise knowledge of the relevant nuclear matrix elements is taken into account in the analysis. We derive the ranges of values of tan^2 theta_\odot, theta_\odot being the mixing angle which controls the solar neutrino oscillations, and of the nuclear matrix element uncertainty factor, for which the measurement of |<m>| would allow one to discriminate between the NH and IH, NH and QD and IH and QD spectra.
1508.04814
Sylvain Fichet
Sylvain Fichet, Gero von Gersdorff
Effective theory for neutral resonances and a statistical dissection of the ATLAS diboson excess
31 pages
null
10.1007/JHEP12(2015)089
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We classify the complete set of dimension-5 operators relevant for the resonant production of a singlet of spin 0 or 2 linearly coupled to the Standard Model (SM). We compute the decay width of such states as a function of the effective couplings, and provide the matching to various well-motivated New Physics scenarios. We then investigate the possibility that one of these neutral resonances be at the origin of the excess in diboson production recently reported by the ATLAS collaboration. We perform a shape analysis of the excess under full consideration of the systematic uncertainties to extract the width $\Gamma_{\rm tot}$ of the hypothetical resonance, finding it to be in the range 26 GeV $<\Gamma_{\rm tot}<$ 144 GeV at 95\% C.L. We then point out that the three overlapping selections $WW$, $WZ$, $ZZ$ reported by ATLAS follow a joint trivariate Poisson distribution, which opens the possibility of a thorough likelihood analysis of the event rates. The background systematic uncertainties are also included in our analysis. We show that the data do not require $W\!Z$ production and could thus in principle be explained by neutral resonances. We then use both the information on the width and the cross section, which prove to be highly complementary, to test the effective Lagrangians of singlet resonances. Regarding specific models, we find that neither scalars coupled via the Higgs-portal nor the Randall-Sundrum (RS) radion can explain the ATLAS anomaly. The RS graviton with all matter on the infrared (IR) brane can in principle fit the observed excess, while the RS model with matter propagating in the bulk requires the presence of IR brane kinetic terms for the gauge fields.
[ { "created": "Wed, 19 Aug 2015 22:16:52 GMT", "version": "v1" } ]
2016-01-27
[ [ "Fichet", "Sylvain", "" ], [ "von Gersdorff", "Gero", "" ] ]
We classify the complete set of dimension-5 operators relevant for the resonant production of a singlet of spin 0 or 2 linearly coupled to the Standard Model (SM). We compute the decay width of such states as a function of the effective couplings, and provide the matching to various well-motivated New Physics scenarios. We then investigate the possibility that one of these neutral resonances be at the origin of the excess in diboson production recently reported by the ATLAS collaboration. We perform a shape analysis of the excess under full consideration of the systematic uncertainties to extract the width $\Gamma_{\rm tot}$ of the hypothetical resonance, finding it to be in the range 26 GeV $<\Gamma_{\rm tot}<$ 144 GeV at 95\% C.L. We then point out that the three overlapping selections $WW$, $WZ$, $ZZ$ reported by ATLAS follow a joint trivariate Poisson distribution, which opens the possibility of a thorough likelihood analysis of the event rates. The background systematic uncertainties are also included in our analysis. We show that the data do not require $W\!Z$ production and could thus in principle be explained by neutral resonances. We then use both the information on the width and the cross section, which prove to be highly complementary, to test the effective Lagrangians of singlet resonances. Regarding specific models, we find that neither scalars coupled via the Higgs-portal nor the Randall-Sundrum (RS) radion can explain the ATLAS anomaly. The RS graviton with all matter on the infrared (IR) brane can in principle fit the observed excess, while the RS model with matter propagating in the bulk requires the presence of IR brane kinetic terms for the gauge fields.
1910.06308
Hajime Fukuda
Hajime Fukuda and Kazunori Nakayama
Aspects of Nonlinear Effect on Black Hole Superradiance
27 pages, 5 figures
null
10.1007/JHEP01(2020)128
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Under some conditions, light boson fields grow exponentially around a rotating black hole, called the superradiance instability. We discuss effects of nonlinear interactions of the boson on the instability. In particular, we focus on the effect of the particle production and show that the growth of the boson cloud may be saturated much before the black hole spin is extracted by the boson cloud, while the nonlinear interactions also induce the boson emission. For application, we revisit the superradiant instability of the standard model photon, axion and hidden photon.
[ { "created": "Mon, 14 Oct 2019 17:46:07 GMT", "version": "v1" } ]
2020-02-19
[ [ "Fukuda", "Hajime", "" ], [ "Nakayama", "Kazunori", "" ] ]
Under some conditions, light boson fields grow exponentially around a rotating black hole, called the superradiance instability. We discuss effects of nonlinear interactions of the boson on the instability. In particular, we focus on the effect of the particle production and show that the growth of the boson cloud may be saturated much before the black hole spin is extracted by the boson cloud, while the nonlinear interactions also induce the boson emission. For application, we revisit the superradiant instability of the standard model photon, axion and hidden photon.
1812.03860
Jin-Lei Yang
Jin-Lei Yang, Tai-Fu Feng, Yu-Li Yan, Wei Li, Shu-Min Zhao, Hai-Bin Zhang
Lepton-flavor violation and two loop electroweak corrections to $(g-2)_\mu$ in the B-L symmetry SSM
27 pages,9 figures, Published in PRD. arXiv admin note: text overlap with arXiv:1803.09904, arXiv:1806.01476
Phys. Rev. D 99, 015002 (2019)
10.1103/PhysRevD.99.015002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged lepton flavor violating processes are forbidden in the standard model (SM), hence the observation of charged lepton flavor transitions would represent a clear signal of new physics beyond the standard Model. In this work, we investigate some lepton flavor violating processes in the minimal supersymmetric extension of the SM with local $B-L$ gauge symmetry (B-LSSM). And including the corrections from some two loop diagrams to the anomalous dipole moments (MDM) of muon, we discuss the corresponding constraint on the relevant parameter space of the model. Considering the constraints from updated experimental data, the numerical results show that, new contributions in the B-LSSM enhance the MSSM predictions on the rates of $l_j-l_i$ transitions about one order of magnitude, and also enhance the MSSM prediction on the muon MDM. In addition, two loop electroweak corrections can make important contributions to the muon MDM in the B-LSSM.
[ { "created": "Fri, 7 Dec 2018 05:43:26 GMT", "version": "v1" }, { "created": "Fri, 4 Jan 2019 06:06:54 GMT", "version": "v2" } ]
2019-01-07
[ [ "Yang", "Jin-Lei", "" ], [ "Feng", "Tai-Fu", "" ], [ "Yan", "Yu-Li", "" ], [ "Li", "Wei", "" ], [ "Zhao", "Shu-Min", "" ], [ "Zhang", "Hai-Bin", "" ] ]
Charged lepton flavor violating processes are forbidden in the standard model (SM), hence the observation of charged lepton flavor transitions would represent a clear signal of new physics beyond the standard Model. In this work, we investigate some lepton flavor violating processes in the minimal supersymmetric extension of the SM with local $B-L$ gauge symmetry (B-LSSM). And including the corrections from some two loop diagrams to the anomalous dipole moments (MDM) of muon, we discuss the corresponding constraint on the relevant parameter space of the model. Considering the constraints from updated experimental data, the numerical results show that, new contributions in the B-LSSM enhance the MSSM predictions on the rates of $l_j-l_i$ transitions about one order of magnitude, and also enhance the MSSM prediction on the muon MDM. In addition, two loop electroweak corrections can make important contributions to the muon MDM in the B-LSSM.
hep-ph/0312254
Daniel Zwanziger
Daniel Zwanziger
Analytic calculation of color-Coulomb potential and color confinement
12 pages
Phys.Rev. D70 (2004) 094034
10.1103/PhysRevD.70.094034
null
hep-ph
null
We develop a calculational scheme in Coulomb and temporal gauge that respects gauge invariance and is most easily applied to the infrared asymptotic region of QCD. It resembles the Dyson-Schwinger equations of Euclidean quantum field theory in Landau gauge, but is 3-dimensional. A simple calculation yields a color-Coulomb potential that behaves at large $R$ approximately like $V_{\rm coul}(R) \sim R^{[1-0.2(d-1)]}$ for spatial dimension $1 \leq d \leq 3$. This is a linearly rising potential plus a rather weak dependence on $d$.
[ { "created": "Thu, 18 Dec 2003 13:01:04 GMT", "version": "v1" } ]
2009-11-10
[ [ "Zwanziger", "Daniel", "" ] ]
We develop a calculational scheme in Coulomb and temporal gauge that respects gauge invariance and is most easily applied to the infrared asymptotic region of QCD. It resembles the Dyson-Schwinger equations of Euclidean quantum field theory in Landau gauge, but is 3-dimensional. A simple calculation yields a color-Coulomb potential that behaves at large $R$ approximately like $V_{\rm coul}(R) \sim R^{[1-0.2(d-1)]}$ for spatial dimension $1 \leq d \leq 3$. This is a linearly rising potential plus a rather weak dependence on $d$.
1707.07858
Wei Chao
Wei Chao
Phenomenology of the gauge symmetry for right-handed fermions
17 pages, 6 figures, more references added
null
10.1140/epjc/s10052-018-5547-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate the phenomenology of the U(1) gauge symmetry for right-handed fermions, where three right-handed neutrinos are introduced for anomalies cancellation. Constraints on the new gauge boson $Z_{\mathbf{R}}$ arising from $Z-Z^\prime$ mixing as well as the upper bound of $Z^\prime$ production cross section in di-lepton channel at the LHC are presented. We further study the neutrino mass generation and the phenomenology of $Z_{\mathbf{R}}$-portal dark matter in this model. The lightest right-handed neutrino can be the cold dark matter candidate stabilized by a $Z_2$ flavor symmetry. Our results show that active neutrino masses can be generated via the modified type-II seesaw mechanism; right-handed neutrino dark matter is available only for its mass at near the resonant regime of the SM Higgs and/or the new bosons; constraint from the dilepton search at the LHC is stronger than that from the $Z-Z^\prime$ mixing only for $g_\mathbf{R}<0.121$, where $g_\mathbf{R}$ is the new gauge coupling.
[ { "created": "Tue, 25 Jul 2017 09:04:40 GMT", "version": "v1" }, { "created": "Tue, 1 Aug 2017 10:10:20 GMT", "version": "v2" } ]
2018-03-14
[ [ "Chao", "Wei", "" ] ]
In this paper we investigate the phenomenology of the U(1) gauge symmetry for right-handed fermions, where three right-handed neutrinos are introduced for anomalies cancellation. Constraints on the new gauge boson $Z_{\mathbf{R}}$ arising from $Z-Z^\prime$ mixing as well as the upper bound of $Z^\prime$ production cross section in di-lepton channel at the LHC are presented. We further study the neutrino mass generation and the phenomenology of $Z_{\mathbf{R}}$-portal dark matter in this model. The lightest right-handed neutrino can be the cold dark matter candidate stabilized by a $Z_2$ flavor symmetry. Our results show that active neutrino masses can be generated via the modified type-II seesaw mechanism; right-handed neutrino dark matter is available only for its mass at near the resonant regime of the SM Higgs and/or the new bosons; constraint from the dilepton search at the LHC is stronger than that from the $Z-Z^\prime$ mixing only for $g_\mathbf{R}<0.121$, where $g_\mathbf{R}$ is the new gauge coupling.
hep-ph/9608262
He Xiao-Gang
Xiao-Gang He and A. Soni
Color-Octet Contribution and Direct CP Violation in $B\to \psi (\psi') X$
12 pages, Revtex, Three figures
Phys.Lett.B391:456-460,1997
10.1016/S0370-2693(96)01466-9
BNL-. UM-P-96/68
hep-ph
null
We study $c \bar c$ color-octet contribution to $B\to \psi (\psi') X$. When this contribution is included, the theoretical predictions for the branching ratios become in much better agreement with the experiment. This mechanism also enhances the partial rate asymmetries by about a factor of five. The inclusive $\psi(\psi')$ resulting from $b\to d+{}$gluon can have asymmetry around a few percent whereas those from $b\to s+{}$gluon has it around $4\times 10^{-4}$. The asymmetry in the former modes should be observable, to a significance of $3\sigma$, with about $(1-10)\times 10^8B$ mesons.
[ { "created": "Thu, 8 Aug 1996 02:01:59 GMT", "version": "v1" }, { "created": "Fri, 9 Aug 1996 04:04:57 GMT", "version": "v2" } ]
2014-11-17
[ [ "He", "Xiao-Gang", "" ], [ "Soni", "A.", "" ] ]
We study $c \bar c$ color-octet contribution to $B\to \psi (\psi') X$. When this contribution is included, the theoretical predictions for the branching ratios become in much better agreement with the experiment. This mechanism also enhances the partial rate asymmetries by about a factor of five. The inclusive $\psi(\psi')$ resulting from $b\to d+{}$gluon can have asymmetry around a few percent whereas those from $b\to s+{}$gluon has it around $4\times 10^{-4}$. The asymmetry in the former modes should be observable, to a significance of $3\sigma$, with about $(1-10)\times 10^8B$ mesons.
hep-ph/0101222
Sandipan Mohanty
B. Andersson, F. Soderberg, S. Mohanty
Alternative Scenarios for the Fragmentation of a Gluonic Lund String
7 pages, 3 figures, to appear in the Proceedings of the XXX'th International Symposium on Multiparticle Dynamics (Oct 9-15, 2000), Lake Balaton, Hungary
null
null
null
hep-ph
null
The assumptions in the Lund model suffice to prescribe a unique stochastic process for the fragmentation of a string into a set of hadrons, so long as the string is "flat", ie as long as the state described by the string consists only of a quark and an antiquark stretching a constant force field between them. Emission of gluons causes the string to trace more complicated surfaces in Minkowski space, and some form of generalization of the 1+1 dimensional model is required. One such generalizaiotn has been developed and implemented as a Monte Carlo routine "JETSET" by Torbj\"orn Sj\"ostrand, which has been hightly successful in describing experimental data. But there are theoretical reasons to believe that the fragmentation scheme employed in JETSET is not entirely satisfactory; most notably, non-adherance to the Lund Area law, and certain problems in handling transverse momenta. A few alternative scenarios, which we have examined in detail and implemented in separate computer programs, will be presented here, with comparisons to JETSET in certain simple cases. Our effort has been to preserve the area law for the fragmentation of a gluonic string, while we explored the possibility of allowing the fragmentation process to reshape the string surface slightly.
[ { "created": "Fri, 19 Jan 2001 19:40:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Andersson", "B.", "" ], [ "Soderberg", "F.", "" ], [ "Mohanty", "S.", "" ] ]
The assumptions in the Lund model suffice to prescribe a unique stochastic process for the fragmentation of a string into a set of hadrons, so long as the string is "flat", ie as long as the state described by the string consists only of a quark and an antiquark stretching a constant force field between them. Emission of gluons causes the string to trace more complicated surfaces in Minkowski space, and some form of generalization of the 1+1 dimensional model is required. One such generalizaiotn has been developed and implemented as a Monte Carlo routine "JETSET" by Torbj\"orn Sj\"ostrand, which has been hightly successful in describing experimental data. But there are theoretical reasons to believe that the fragmentation scheme employed in JETSET is not entirely satisfactory; most notably, non-adherance to the Lund Area law, and certain problems in handling transverse momenta. A few alternative scenarios, which we have examined in detail and implemented in separate computer programs, will be presented here, with comparisons to JETSET in certain simple cases. Our effort has been to preserve the area law for the fragmentation of a gluonic string, while we explored the possibility of allowing the fragmentation process to reshape the string surface slightly.
hep-ph/9802239
Jacques C. R. Bloch
D. Atkinson and J.C.R. Bloch
QCD in the Infrared with Exact Angular Integrations
7 pages, latex
Mod.Phys.Lett.A13:1055-1062,1998
10.1142/S0217732398001121
RUGTh-980204
hep-ph hep-th nucl-th
null
In a previous paper we have shown that in quantum chromodynamics the gluon propagator vanishes in the infrared limit, while the ghost propagator is more singular than a simple pole. These results were obtained after angular averaging, but in the current paper we go beyond this approximation and perform an exact calculation of the angular integrals. The powers of the infrared behaviour of the propagators are changed substantially. We find the very intriguing result that the gluon propagator vanishes in the infrared exactly like p^2, whilst the ghost propagator is exactly as singular as 1/p^4. We also find that the value of the infrared fixed point of the QCD coupling is much decreased from the y-max estimate: it is now equal to 4\pi/3.
[ { "created": "Wed, 4 Feb 1998 08:00:51 GMT", "version": "v1" } ]
2009-01-14
[ [ "Atkinson", "D.", "" ], [ "Bloch", "J. C. R.", "" ] ]
In a previous paper we have shown that in quantum chromodynamics the gluon propagator vanishes in the infrared limit, while the ghost propagator is more singular than a simple pole. These results were obtained after angular averaging, but in the current paper we go beyond this approximation and perform an exact calculation of the angular integrals. The powers of the infrared behaviour of the propagators are changed substantially. We find the very intriguing result that the gluon propagator vanishes in the infrared exactly like p^2, whilst the ghost propagator is exactly as singular as 1/p^4. We also find that the value of the infrared fixed point of the QCD coupling is much decreased from the y-max estimate: it is now equal to 4\pi/3.
2111.12101
Niko Jokela
Niko Jokela, Matti J\"arvinen, Jere Remes
Holographic QCD in the NICER era
22 pages, 8 figures; v2: refs. added
null
10.1103/PhysRevD.105.086005
HIP-2021-40/TH,APCTP Pre2021-033
hep-ph astro-ph.HE hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze families of hybrid equations of state of cold QCD matter, which combine input from gauge/gravity duality and from various ab initio methods for nuclear matter at low density, and predict that all neutron stars are fully hadronic without quark matter cores. We focus on constraints from recent measurements by the NICER telescope on the radius and mass of the millisecond pulsar PSR J0740+6620. These results are found to be consistent with our approach: they set only mild constraints on the hybrid equations of state, and favor the most natural models which are relatively stiff at low density. Adding an upper bound on the maximal mass of neutron stars, as suggested by the analysis of the GW170817 neutron star merger event, tightens the constraints considerably. We discuss updated predictions on observables such as the transition density and latent heat of the nuclear to quark matter transition as well as the masses, radii, and tidal deformabilities of neutron stars.
[ { "created": "Tue, 23 Nov 2021 19:00:02 GMT", "version": "v1" }, { "created": "Fri, 24 Dec 2021 10:49:16 GMT", "version": "v2" } ]
2022-04-20
[ [ "Jokela", "Niko", "" ], [ "Järvinen", "Matti", "" ], [ "Remes", "Jere", "" ] ]
We analyze families of hybrid equations of state of cold QCD matter, which combine input from gauge/gravity duality and from various ab initio methods for nuclear matter at low density, and predict that all neutron stars are fully hadronic without quark matter cores. We focus on constraints from recent measurements by the NICER telescope on the radius and mass of the millisecond pulsar PSR J0740+6620. These results are found to be consistent with our approach: they set only mild constraints on the hybrid equations of state, and favor the most natural models which are relatively stiff at low density. Adding an upper bound on the maximal mass of neutron stars, as suggested by the analysis of the GW170817 neutron star merger event, tightens the constraints considerably. We discuss updated predictions on observables such as the transition density and latent heat of the nuclear to quark matter transition as well as the masses, radii, and tidal deformabilities of neutron stars.
1512.06458
Ankit Beniwal
Ankit Beniwal, Filip Rajec, Christopher Savage, Pat Scott, Christoph Weniger, Martin White and Anthony G. Williams
Combined analysis of effective Higgs portal dark matter models
53 pages, 16 figures, REVTeX-4.1 processed with BibTeX and pdfLaTeX. v2: added references; submitted to Phys. Rev. D. v3: added references and corrected few typos; matches the version accepted for publication in Phys. Rev. D. v4: matches the version published in Phys. Rev. D
Phys. Rev. D 93, 115016 (2016)
10.1103/PhysRevD.93.115016
ADP-15-52/T954
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We combine and extend the analyses of effective scalar, vector, Majorana and Dirac fermion Higgs portal models of dark matter (DM), in which DM couples to the Standard Model (SM) Higgs boson via an operator of the form $\mathcal{O}_{\textrm{DM}}\, H^\dagger H$. For the fermion models, we take an admixture of scalar $\overline{\psi} \psi$ and pseudoscalar $\overline{\psi} i\gamma_5 \psi$ interaction terms. For each model, we apply constraints on the parameter space based on the Planck measured DM relic density and the LHC limits on the Higgs invisible branching ratio. For the first time, we perform a consistent study of the indirect detection prospects for these models based on the WMAP7/Planck observations of the cosmic microwave background, a combined analysis of 15 dwarf spheroidal galaxies by Fermi-LAT and the upcoming Cherenkov Telescope Array (CTA). We also perform a correct treatment of the momentum-dependent direct search cross section that arises from the pseudoscalar interaction term in the fermionic DM theories. We find, in line with previous studies, that current and future direct search experiments such as LUX and XENON1T can exclude much of the parameter space, and we demonstrate that a joint observation in both indirect and direct searches is possible for high mass weakly interacting massive particles. In the case of a pure pseudoscalar interaction of a fermionic DM candidate, future gamma-ray searches are the only class of experiment capable of probing the high mass range of the theory.
[ { "created": "Sun, 20 Dec 2015 23:58:14 GMT", "version": "v1" }, { "created": "Thu, 28 Jan 2016 04:59:56 GMT", "version": "v2" }, { "created": "Thu, 26 May 2016 17:08:29 GMT", "version": "v3" }, { "created": "Tue, 14 Jun 2016 07:14:19 GMT", "version": "v4" } ]
2016-06-15
[ [ "Beniwal", "Ankit", "" ], [ "Rajec", "Filip", "" ], [ "Savage", "Christopher", "" ], [ "Scott", "Pat", "" ], [ "Weniger", "Christoph", "" ], [ "White", "Martin", "" ], [ "Williams", "Anthony G.", "" ] ]
We combine and extend the analyses of effective scalar, vector, Majorana and Dirac fermion Higgs portal models of dark matter (DM), in which DM couples to the Standard Model (SM) Higgs boson via an operator of the form $\mathcal{O}_{\textrm{DM}}\, H^\dagger H$. For the fermion models, we take an admixture of scalar $\overline{\psi} \psi$ and pseudoscalar $\overline{\psi} i\gamma_5 \psi$ interaction terms. For each model, we apply constraints on the parameter space based on the Planck measured DM relic density and the LHC limits on the Higgs invisible branching ratio. For the first time, we perform a consistent study of the indirect detection prospects for these models based on the WMAP7/Planck observations of the cosmic microwave background, a combined analysis of 15 dwarf spheroidal galaxies by Fermi-LAT and the upcoming Cherenkov Telescope Array (CTA). We also perform a correct treatment of the momentum-dependent direct search cross section that arises from the pseudoscalar interaction term in the fermionic DM theories. We find, in line with previous studies, that current and future direct search experiments such as LUX and XENON1T can exclude much of the parameter space, and we demonstrate that a joint observation in both indirect and direct searches is possible for high mass weakly interacting massive particles. In the case of a pure pseudoscalar interaction of a fermionic DM candidate, future gamma-ray searches are the only class of experiment capable of probing the high mass range of the theory.
1509.01789
Vadim Baru
V. Baru, E. Epelbaum, A.A. Filin, J. Gegelia, A.V. Nefediev
Binding energy of the $X(3872)$ at unphysical pion masses
24 pages, 4 figures
Phys. Rev. D 92, 114016 (2015)
10.1103/PhysRevD.92.114016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chiral extrapolation of the $X(3872)$ binding energy is investigated using the modified Weinberg formulation of chiral effective field theory for the $D \bar{D}^*$ scattering. Given its explicit renormalisability, this approach is particularly useful to explore the interplay of the long- and short-range $D \bar{D}^*$ forces in the $X(3872)$ from studying the light-quark (pion) mass dependence of its binding energy. In particular, the parameter-free leading-order calculation shows that the $X$-pole disappears for unphysical large pion masses. On the other hand, without contradicting the naive dimensional analysis, the higher-order pion-mass-dependent contact interaction can change the slope of the binding energy at the physical point yielding the opposite scenario of a stronger bound $X$ at pion masses larger than its physical value. An important role of the pion dynamics and of the 3-body $D\bar{D}\pi$ effects for chiral extrapolations of the $X$-pole is emphasised. The results of the present study should be of practical value for the lattice simulations since they provide a non-trivial connection between lattice points at unphysical pion masses and the physical world.
[ { "created": "Sun, 6 Sep 2015 09:38:56 GMT", "version": "v1" } ]
2015-12-16
[ [ "Baru", "V.", "" ], [ "Epelbaum", "E.", "" ], [ "Filin", "A. A.", "" ], [ "Gegelia", "J.", "" ], [ "Nefediev", "A. V.", "" ] ]
Chiral extrapolation of the $X(3872)$ binding energy is investigated using the modified Weinberg formulation of chiral effective field theory for the $D \bar{D}^*$ scattering. Given its explicit renormalisability, this approach is particularly useful to explore the interplay of the long- and short-range $D \bar{D}^*$ forces in the $X(3872)$ from studying the light-quark (pion) mass dependence of its binding energy. In particular, the parameter-free leading-order calculation shows that the $X$-pole disappears for unphysical large pion masses. On the other hand, without contradicting the naive dimensional analysis, the higher-order pion-mass-dependent contact interaction can change the slope of the binding energy at the physical point yielding the opposite scenario of a stronger bound $X$ at pion masses larger than its physical value. An important role of the pion dynamics and of the 3-body $D\bar{D}\pi$ effects for chiral extrapolations of the $X$-pole is emphasised. The results of the present study should be of practical value for the lattice simulations since they provide a non-trivial connection between lattice points at unphysical pion masses and the physical world.
2005.05297
Jusak Tandean
Jhih-Ying Su, Jusak Tandean
Seeking massless dark photons in the decays of charmed hadrons
15 pages, no figure, minor errors corrected, matches publication
Phys. Rev. D 102, 115029 (2020)
10.1103/PhysRevD.102.115029
NCTS-PH/2006
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A massless dark photon could affect standard-model particles only via higher-dimensional operators and would therefore have eluded recent searches for its massive counterpart, which were based on the assumption that the latter had renormalizable interactions with known fermions due to gauge kinetic mixing. In this study we entertain the possibility that the massless dark photon has nonnegligible flavor-changing dipole-type couplings with the $u$ and $c$ quarks, giving rise to the decays of charmed hadrons into a lighter hadron plus missing energy carried away by the dark photon. We propose to investigate decays of this kind, especially those in which the parents are the charmed pseudoscalar-mesons $D^+$, $D^0$, and $D_s^+$ and singly charmed baryons $\Lambda_c^+$, $\Xi_c^+$, and $\Xi_c^0$. Employing a simplified new-physics model satisfying the relevant constraints, we find that the branching fractions of these processes could be as large as several times $10^{-5}$. This suggests that one or more of them might in the near future fall within reach of the ongoing Belle II and BESIII experiments. Since the same underlying operators are responsible for all of these transitions, detecting one of them automatically implies particular predictions for the others, allowing for additional experimental checks on the massless-dark-photon scenario.
[ { "created": "Mon, 11 May 2020 17:57:33 GMT", "version": "v1" }, { "created": "Mon, 18 May 2020 14:43:34 GMT", "version": "v2" }, { "created": "Thu, 24 Dec 2020 17:54:24 GMT", "version": "v3" } ]
2020-12-25
[ [ "Su", "Jhih-Ying", "" ], [ "Tandean", "Jusak", "" ] ]
A massless dark photon could affect standard-model particles only via higher-dimensional operators and would therefore have eluded recent searches for its massive counterpart, which were based on the assumption that the latter had renormalizable interactions with known fermions due to gauge kinetic mixing. In this study we entertain the possibility that the massless dark photon has nonnegligible flavor-changing dipole-type couplings with the $u$ and $c$ quarks, giving rise to the decays of charmed hadrons into a lighter hadron plus missing energy carried away by the dark photon. We propose to investigate decays of this kind, especially those in which the parents are the charmed pseudoscalar-mesons $D^+$, $D^0$, and $D_s^+$ and singly charmed baryons $\Lambda_c^+$, $\Xi_c^+$, and $\Xi_c^0$. Employing a simplified new-physics model satisfying the relevant constraints, we find that the branching fractions of these processes could be as large as several times $10^{-5}$. This suggests that one or more of them might in the near future fall within reach of the ongoing Belle II and BESIII experiments. Since the same underlying operators are responsible for all of these transitions, detecting one of them automatically implies particular predictions for the others, allowing for additional experimental checks on the massless-dark-photon scenario.
1411.6845
Lidia Kalinovskaya
D. Bardin, L. Kalinovskaya, E. Uglov and W. von Schlippe
$J$ functions for the process ud$\to$WA
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a description of the universal approach for analytic calculations for a certain class of $J$ functions for six topologies of the boxes for process $ud\rightarrow WA$. These functions $J$ arise at the reduction of infrared divergent box diagrams. The standard Passarino--Veltman reduction of four-point box diagram with an internal photon line connecting two external lines on the mass shell leads to infrared-divergent and mass-singular $D_0$ functions. In the system SANC a systematic procedure is adopted to separate both types of singularities into the simplest objects, namely $C_0$ functions. The functions $J$, in turn, are represented as certain linear combinations of the standard $D_0$ and $C_0$ functions. The subtracted $J$ functions are free of both types of singularities and are expressed as explicit and compact linear combinations of dilogarithm functions. We present extensive comparisons of numerical results of SANC with those obtained with the aid of the LoopTools package.
[ { "created": "Tue, 25 Nov 2014 12:55:40 GMT", "version": "v1" }, { "created": "Mon, 29 Dec 2014 10:06:55 GMT", "version": "v2" } ]
2014-12-30
[ [ "Bardin", "D.", "" ], [ "Kalinovskaya", "L.", "" ], [ "Uglov", "E.", "" ], [ "von Schlippe", "W.", "" ] ]
In this paper we present a description of the universal approach for analytic calculations for a certain class of $J$ functions for six topologies of the boxes for process $ud\rightarrow WA$. These functions $J$ arise at the reduction of infrared divergent box diagrams. The standard Passarino--Veltman reduction of four-point box diagram with an internal photon line connecting two external lines on the mass shell leads to infrared-divergent and mass-singular $D_0$ functions. In the system SANC a systematic procedure is adopted to separate both types of singularities into the simplest objects, namely $C_0$ functions. The functions $J$, in turn, are represented as certain linear combinations of the standard $D_0$ and $C_0$ functions. The subtracted $J$ functions are free of both types of singularities and are expressed as explicit and compact linear combinations of dilogarithm functions. We present extensive comparisons of numerical results of SANC with those obtained with the aid of the LoopTools package.
1511.06108
Marco van Leeuwen
Marco van Leeuwen
Jet Fragmentation and Jet Shapes in JEWEL and Q-PYTHIA
Proceedings of the 7th International Conference on Hard and Electromagnetic Probes of High Energy Nuclear Collisions (Hard Probes 2015), 4 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A study of several observables characterising fragment distributions of medium-modified parton showers using the JEWEL and Q-PYTHIA models is presented, with emphasis on the relation between the different observables.
[ { "created": "Thu, 19 Nov 2015 09:58:58 GMT", "version": "v1" } ]
2015-11-20
[ [ "van Leeuwen", "Marco", "" ] ]
A study of several observables characterising fragment distributions of medium-modified parton showers using the JEWEL and Q-PYTHIA models is presented, with emphasis on the relation between the different observables.
hep-ph/0503018
Silvano Simula
M. Osipenko, S. Simula, W. Melnitchouk, P. Bosted, V. Burkert, E. Christy, K. Griffioen, C. Keppel, S. Kuhn and G. Ricco
Global Analysis of Data on the Proton Structure Function g1 and Extraction of its Moments
18 pages, 13 figures, to appear in Phys. Rev. D
Phys.Rev.D71:054007,2005
10.1103/PhysRevD.71.054007
Preprint JLAB-PHY-05-9, RM3-TH/04-24
hep-ph nucl-th
null
Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)**2. We compute for the first time low-order moments of g1 and study their evolution from small to large values of Q2. The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = sigmaL / sigmaT from Jefferson Lab, as well as a new model for the transverse asymmetry A2 in the resonance region. The contributions of both leading and higher twists are extracted, taking into account effects from radiative corrections beyond the next-to-leading order by means of soft-gluon resummation techniques. The leading twist is determined with remarkably good accuracy and is compared with the predictions obtained using various polarized parton distribution sets available in the literature. The contribution of higher twists to the g1 moments is found to be significantly larger than in the case of the unpolarized structure function F2.
[ { "created": "Wed, 2 Mar 2005 08:57:10 GMT", "version": "v1" } ]
2008-11-26
[ [ "Osipenko", "M.", "" ], [ "Simula", "S.", "" ], [ "Melnitchouk", "W.", "" ], [ "Bosted", "P.", "" ], [ "Burkert", "V.", "" ], [ "Christy", "E.", "" ], [ "Griffioen", "K.", "" ], [ "Keppel", "C.", "" ], [ "Kuhn", "S.", "" ], [ "Ricco", "G.", "" ] ]
Inspired by recent measurements with the CLAS detector at Jefferson Lab, we perform a self-consistent analysis of world data on the proton structure function g1 in the range 0.17 < Q2 < 30 (GeV/c)**2. We compute for the first time low-order moments of g1 and study their evolution from small to large values of Q2. The analysis includes the latest data on both the unpolarized inclusive cross sections and the ratio R = sigmaL / sigmaT from Jefferson Lab, as well as a new model for the transverse asymmetry A2 in the resonance region. The contributions of both leading and higher twists are extracted, taking into account effects from radiative corrections beyond the next-to-leading order by means of soft-gluon resummation techniques. The leading twist is determined with remarkably good accuracy and is compared with the predictions obtained using various polarized parton distribution sets available in the literature. The contribution of higher twists to the g1 moments is found to be significantly larger than in the case of the unpolarized structure function F2.
1405.1054
Danny Marfatia
Vernon Barger, Atri Bhattacharya, Animesh Chatterjee, Raj Gandhi, Danny Marfatia and Mehedi Masud
Optimal configurations of the Deep Underground Neutrino Experiment
25 pages, 17 figures, 6 tables. Expanded version to appear in IJMPA
Int. J. Mod. Phys. A 31, 1650020 (2016)
10.1142/S0217751X16500202
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a comprehensive study of the ability of the Deep Underground Neutrino Experiment (DUNE) to answer outstanding questions in the neutrino sector. We consider the sensitivities to the mass hierarchy, the octant of \theta_{23} and to CP violation using data from beam and atmospheric neutrinos. We evaluate the dependencies on the precision with which \theta_{13} will be measured by reactor experiments, on the detector size, beam power and exposure time, on detector magnetization, and on the systematic uncertainties achievable with and without a near detector. We find that a 35 kt far detector in DUNE with a near detector will resolve the eight-fold degeneracy that is intrinsic to long baseline experiments and will meet the primary goals of oscillation physics that it is designed for.
[ { "created": "Mon, 5 May 2014 20:08:09 GMT", "version": "v1" }, { "created": "Mon, 28 Dec 2015 18:37:09 GMT", "version": "v2" } ]
2016-03-04
[ [ "Barger", "Vernon", "" ], [ "Bhattacharya", "Atri", "" ], [ "Chatterjee", "Animesh", "" ], [ "Gandhi", "Raj", "" ], [ "Marfatia", "Danny", "" ], [ "Masud", "Mehedi", "" ] ]
We perform a comprehensive study of the ability of the Deep Underground Neutrino Experiment (DUNE) to answer outstanding questions in the neutrino sector. We consider the sensitivities to the mass hierarchy, the octant of \theta_{23} and to CP violation using data from beam and atmospheric neutrinos. We evaluate the dependencies on the precision with which \theta_{13} will be measured by reactor experiments, on the detector size, beam power and exposure time, on detector magnetization, and on the systematic uncertainties achievable with and without a near detector. We find that a 35 kt far detector in DUNE with a near detector will resolve the eight-fold degeneracy that is intrinsic to long baseline experiments and will meet the primary goals of oscillation physics that it is designed for.
hep-ph/0507139
Alexei Sheplyakov A.
A. Bednyakov, D.I. Kazakov, A. Sheplyakov
On the two-loop O(\alpha_s^2) corrections to the pole mass of the t-quark in the MSSM
AMS-LaTeX, 12 pages, 7 PostScript figures
Phys.Atom.Nucl.71:343-350,2008
10.1007/s11450-008-2015-6
null
hep-ph
null
The paper is devoted to the calculation of additional two-loop O(\alpha_s^2) MSSM corrections to the relation between the pole mass of the t-quark and its running mass in the DR scheme. The value of the second order contribution from large mass expansion is studied. As a by-product we calcutated two-loop anomalous dimension of the running quark DR-mass in the supersymmetric QCD.
[ { "created": "Tue, 12 Jul 2005 08:14:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bednyakov", "A.", "" ], [ "Kazakov", "D. I.", "" ], [ "Sheplyakov", "A.", "" ] ]
The paper is devoted to the calculation of additional two-loop O(\alpha_s^2) MSSM corrections to the relation between the pole mass of the t-quark and its running mass in the DR scheme. The value of the second order contribution from large mass expansion is studied. As a by-product we calcutated two-loop anomalous dimension of the running quark DR-mass in the supersymmetric QCD.
2302.07593
Sven-Olaf Moch
G. Falcioni, F. Herzog (U. Edinburgh), S. Moch (U. Hamburg) and A. Vogt (Liverpool U.)
Four-loop splitting functions in QCD -- The quark-quark case
17 pages latex, 2 figures, 2 ancillary files (FORM file with results and FORTRAN subroutine)
null
10.1016/j.physletb.2023.137944
DESY 23--022, LTH 1333
hep-ph
http://creativecommons.org/licenses/by/4.0/
We have computed the even-$N$ moments $N\leq 20$ of the pure-singlet quark splitting function $P_{\,\rm ps}$ at the fourth order of perturbative QCD via the anomalous dimensions of off-shell flavour-singlet operator matrix elements. Our results, derived analytically for a general gauge group, agree with all results obtained for this function so far, in particular with the lowest six even moments obtained via physical cross sections. Using these results and all available endpoint constraints, we construct approximations for $P_{\rm ps}$ at four loops that should be sufficient for most collider-physics applications. Together with the known results for the non-singlet splitting function $P_{\rm ns}^{\,+}$ at this order, this effectively completes the quark-quark contribution for the evolution of parton distribution at N$^{\:\!3}$LO accuracy. Our new results thus provide a major step towards fully consistent N$^{\:\!3}$LO calculations at the LHC and the reduction of the residual uncertainty in the parton evolution to the percent level.
[ { "created": "Wed, 15 Feb 2023 11:19:01 GMT", "version": "v1" } ]
2023-06-14
[ [ "Falcioni", "G.", "", "U. Edinburgh" ], [ "Herzog", "F.", "", "U. Edinburgh" ], [ "Moch", "S.", "", "U. Hamburg" ], [ "Vogt", "A.", "", "Liverpool U." ] ]
We have computed the even-$N$ moments $N\leq 20$ of the pure-singlet quark splitting function $P_{\,\rm ps}$ at the fourth order of perturbative QCD via the anomalous dimensions of off-shell flavour-singlet operator matrix elements. Our results, derived analytically for a general gauge group, agree with all results obtained for this function so far, in particular with the lowest six even moments obtained via physical cross sections. Using these results and all available endpoint constraints, we construct approximations for $P_{\rm ps}$ at four loops that should be sufficient for most collider-physics applications. Together with the known results for the non-singlet splitting function $P_{\rm ns}^{\,+}$ at this order, this effectively completes the quark-quark contribution for the evolution of parton distribution at N$^{\:\!3}$LO accuracy. Our new results thus provide a major step towards fully consistent N$^{\:\!3}$LO calculations at the LHC and the reduction of the residual uncertainty in the parton evolution to the percent level.
hep-ph/0608105
Shunzo Kumano
S. Kumano (KEK, Graduate U. Adv. Studies)
Hadron Physics at J-PARC
8 pages, LaTeX, 3 eps files, Invited talk at the Fifth International Conference on Perspectives in Hadronic Physics: Particle-Nucleus and Nucleus-Nucleus Scattering at Relativistic Energies, May 22-26, 2006, Trieste, Italy, to be published in Nucl. Phys. A
Nucl.Phys.A782:442-449,2007
10.1016/j.nuclphysa.2006.09.022
KEK-TH-1097
hep-ph hep-ex nucl-ex nucl-th
null
An outline is explained for hadron-physics projects at J-PARC, which is considered to be one of the flagship facilities in hadron physics from 2008. The facility provides an intensity frontier with 50 GeV proton beam for nuclear and particle physics. It could cover a wide range of hadron physics from strongly interacting many-body systems with an extended hadronic degree of freedom, strangeness, to new forms of hadrons and hadronic matters. These studies lead not only to create innovative fields of hadron physics but also, possibly, to understand fundamental interactions because of recent progress on AdS/CFT correspondence. At the first stage of the J-PARC operation, hadron topics are mainly on strangeness nuclear physics such as hypernuclei, kaonic nuclei, and possible pentaquark hadrons. Then, the studies could be extended to exotic hadron searches, chiral dynamics in nuclear medium, structure functions, hard exclusive processes, hadron physics in neutrino scattering, and spin structure of the nucleon. With major upgrades of the facility, extensive studies could be done for the nucleon spin, heavy-ion physics, and hadron physics at a high-energy neutrino factory.
[ { "created": "Thu, 10 Aug 2006 04:08:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kumano", "S.", "", "KEK, Graduate U. Adv. Studies" ] ]
An outline is explained for hadron-physics projects at J-PARC, which is considered to be one of the flagship facilities in hadron physics from 2008. The facility provides an intensity frontier with 50 GeV proton beam for nuclear and particle physics. It could cover a wide range of hadron physics from strongly interacting many-body systems with an extended hadronic degree of freedom, strangeness, to new forms of hadrons and hadronic matters. These studies lead not only to create innovative fields of hadron physics but also, possibly, to understand fundamental interactions because of recent progress on AdS/CFT correspondence. At the first stage of the J-PARC operation, hadron topics are mainly on strangeness nuclear physics such as hypernuclei, kaonic nuclei, and possible pentaquark hadrons. Then, the studies could be extended to exotic hadron searches, chiral dynamics in nuclear medium, structure functions, hard exclusive processes, hadron physics in neutrino scattering, and spin structure of the nucleon. With major upgrades of the facility, extensive studies could be done for the nucleon spin, heavy-ion physics, and hadron physics at a high-energy neutrino factory.
1301.5856
Florian Goertz
Adrian Carmona and Florian Goertz
Custodial Leptons and Higgs Decays
33 pages, 12 figures; v2: typos corrected, references added, minor clarifying comments and discussion of new Moriond results added, version published in JHEP
JHEP 1304:163,2013
10.1007/JHEP04(2013)163
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-sa/3.0/
We study the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\tau_R\tau_R decays allows for potentially interesting signals in Higgs physics, while maintaining the good agreement of the Standard Model with precision tests, without significant fine-tuning. Although being viable setups on their own, the models we study can particularly be motivated as the low energy effective theories of the composite Higgs models MCHM_5 and MCHM_10 or the corresponding gauge-Higgs unification models. The spectra can be identified with the light custodians present in these theories. These have the potential to describe the relevant physics in their fermion sectors in a simplified and transparent way. In contrast to previous studies of composite models, we consider the impact of a realistic lepton sector on the Higgs decays. We find significant modifications in the decays to \tau leptons and photons due to the new leptonic resonances. While from a pure low energy perspective an enhancement of the channel pp->h->\gamma\gamma turns out to be possible, if one considers constraints on the parameters from the full structure of the composite models, the decay mode into photons is always reduced. We also demonstrate that taking into account the non-linearity of the Higgs sector does not change the qualitative picture for the decays into \tau-leptons or photons in the case of the dominant Higgs production mechanism.
[ { "created": "Thu, 24 Jan 2013 18:27:28 GMT", "version": "v1" }, { "created": "Thu, 19 Sep 2013 10:56:19 GMT", "version": "v2" } ]
2013-09-20
[ [ "Carmona", "Adrian", "" ], [ "Goertz", "Florian", "" ] ]
We study the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\tau_R\tau_R decays allows for potentially interesting signals in Higgs physics, while maintaining the good agreement of the Standard Model with precision tests, without significant fine-tuning. Although being viable setups on their own, the models we study can particularly be motivated as the low energy effective theories of the composite Higgs models MCHM_5 and MCHM_10 or the corresponding gauge-Higgs unification models. The spectra can be identified with the light custodians present in these theories. These have the potential to describe the relevant physics in their fermion sectors in a simplified and transparent way. In contrast to previous studies of composite models, we consider the impact of a realistic lepton sector on the Higgs decays. We find significant modifications in the decays to \tau leptons and photons due to the new leptonic resonances. While from a pure low energy perspective an enhancement of the channel pp->h->\gamma\gamma turns out to be possible, if one considers constraints on the parameters from the full structure of the composite models, the decay mode into photons is always reduced. We also demonstrate that taking into account the non-linearity of the Higgs sector does not change the qualitative picture for the decays into \tau-leptons or photons in the case of the dominant Higgs production mechanism.
2212.07794
Hakan Akdag
Hakan Akdag, Bastian Kubis, Andreas Wirzba
$C$ and $CP$ violation in effective field theories
76 pages, 1 figure, 12 tables; v2: discussion extended, references added, version published in JHEP
JHEP 06 (2023) 154
10.1007/JHEP06(2023)154
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quest for new sources of the simultaneous violation of $C$ and $CP$ symmetry was popular in the 1960s and has since been mostly neglected for more than half a century. In this work we revisit fundamental quark-level operators that break $C$ and $CP$ up to and including mass dimension 8 for flavor-conserving transitions, relying on the complete operator sets of the so-called Standard Model effective field theory and the low-energy effective field theory. With the formalism of chiral perturbation theory, we match these quark operators to light-meson physics, derive $C$- and $CP$-odd Lagrangians for several processes in the $\eta$, $\eta'$, and pion sectors, and furthermore, as a proof of principle, give estimates for the respective observables in explicit dependence of the underlying high-energy scale for new physics.
[ { "created": "Thu, 15 Dec 2022 13:12:06 GMT", "version": "v1" }, { "created": "Thu, 29 Jun 2023 13:21:25 GMT", "version": "v2" } ]
2023-06-30
[ [ "Akdag", "Hakan", "" ], [ "Kubis", "Bastian", "" ], [ "Wirzba", "Andreas", "" ] ]
The quest for new sources of the simultaneous violation of $C$ and $CP$ symmetry was popular in the 1960s and has since been mostly neglected for more than half a century. In this work we revisit fundamental quark-level operators that break $C$ and $CP$ up to and including mass dimension 8 for flavor-conserving transitions, relying on the complete operator sets of the so-called Standard Model effective field theory and the low-energy effective field theory. With the formalism of chiral perturbation theory, we match these quark operators to light-meson physics, derive $C$- and $CP$-odd Lagrangians for several processes in the $\eta$, $\eta'$, and pion sectors, and furthermore, as a proof of principle, give estimates for the respective observables in explicit dependence of the underlying high-energy scale for new physics.
1204.1000
Pradipta Ghosh
Joydeep Chakrabortty, Pradipta Ghosh, Werner Rodejohann
Lower Limits on $\mu \to e \gamma$ from new Measurements on $U_{e3}$
9 pages, 4 .eps figures; Discussions, 2 new figures and references added, Abstract and text modified, matches with the published version in Physical Review D
Phys. Rev. D 86, 075020 (2012)
10.1103/PhysRevD.86.075020
FTUAM-12-88; IFT-UAM/CSIC-12-29
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New data on the lepton mixing angle $\theta_{13}$ imply that the $e\mu$ element of the matrix $m_\nu m_\nu^\dagger$, where $m_\nu$ is the neutrino Majorana mass matrix, cannot vanish. This implies a lower limit on lepton flavor violating processes in the $e\mu$ sector in a variety of frameworks, including Higgs triplet models or the concept of minimal flavor violation in the lepton sector. We illustrate this for the branching ratio of $\mu \to e \gamma$ in the type II seesaw mechanism, in which a Higgs triplet is responsible for neutrino mass and also mediates lepton flavor violation. We also discuss processes like $\mu\to e\bar{e}e$ and $\mu\to e$ conversion in nuclei. Since these processes have sensitivity on the individual entries of $m_\nu$, their rates can still be vanishingly small.
[ { "created": "Wed, 4 Apr 2012 17:05:07 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2012 13:33:49 GMT", "version": "v2" } ]
2012-10-22
[ [ "Chakrabortty", "Joydeep", "" ], [ "Ghosh", "Pradipta", "" ], [ "Rodejohann", "Werner", "" ] ]
New data on the lepton mixing angle $\theta_{13}$ imply that the $e\mu$ element of the matrix $m_\nu m_\nu^\dagger$, where $m_\nu$ is the neutrino Majorana mass matrix, cannot vanish. This implies a lower limit on lepton flavor violating processes in the $e\mu$ sector in a variety of frameworks, including Higgs triplet models or the concept of minimal flavor violation in the lepton sector. We illustrate this for the branching ratio of $\mu \to e \gamma$ in the type II seesaw mechanism, in which a Higgs triplet is responsible for neutrino mass and also mediates lepton flavor violation. We also discuss processes like $\mu\to e\bar{e}e$ and $\mu\to e$ conversion in nuclei. Since these processes have sensitivity on the individual entries of $m_\nu$, their rates can still be vanishingly small.
1812.00820
Venus Keus
A. Cordero-Cid, J. Hern\'andez-S\'anchez, V. Keus, S. Moretti, D. Rojas, D. Soko{\l}owska
Lepton collider signatures of dark CP violation
19 pages, 4 figures, published version
Eur.\ Phys.\ J.\ C \textbf{80}, no.2, 135 (2020)
10.1140/epjc/s10052-020-7689-0
DMIIP-2018
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an extension of the Standard Model (SM) in which two copies of the SM Higgs doublet are added to the scalar sector. These extra doublets do not develop a vacuum expectation value, hence, they are \textit{inert}. This essentially leads to a 3-Higgs Doublet Model (3HDM) with 2 inert and 1 active scalar doublets, which we denote as I(2+1)HDM. We allow for CP-violation in the \textit{inert} sector, where the lightest \textit{inert} state is protected from decaying to SM particles through the conservation of a $Z_2$ symmetry, so that it is a Dark Matter (DM) candidate. For this scenario, we identify a smoking gun signature of dark CP-violation in the form of production thresholds of pairs of \textit{inert} neutral Higgs bosons at an $e^+e^-$ collider.
[ { "created": "Mon, 3 Dec 2018 15:08:21 GMT", "version": "v1" }, { "created": "Tue, 7 Apr 2020 07:33:16 GMT", "version": "v2" } ]
2020-04-08
[ [ "Cordero-Cid", "A.", "" ], [ "Hernández-Sánchez", "J.", "" ], [ "Keus", "V.", "" ], [ "Moretti", "S.", "" ], [ "Rojas", "D.", "" ], [ "Sokołowska", "D.", "" ] ]
We study an extension of the Standard Model (SM) in which two copies of the SM Higgs doublet are added to the scalar sector. These extra doublets do not develop a vacuum expectation value, hence, they are \textit{inert}. This essentially leads to a 3-Higgs Doublet Model (3HDM) with 2 inert and 1 active scalar doublets, which we denote as I(2+1)HDM. We allow for CP-violation in the \textit{inert} sector, where the lightest \textit{inert} state is protected from decaying to SM particles through the conservation of a $Z_2$ symmetry, so that it is a Dark Matter (DM) candidate. For this scenario, we identify a smoking gun signature of dark CP-violation in the form of production thresholds of pairs of \textit{inert} neutral Higgs bosons at an $e^+e^-$ collider.
hep-ph/0701179
Anatoly D. Erlykin
A.D.Erlykin
The neutron 'thunder' accompanying the extensive air shower
12 pages, 4 figures, accepted by J.Phys.G: Nucl.Part.Phys
J.Phys.G33:565-576,2007
10.1088/0954-3899/34/3/014
null
hep-ph
null
Simulations show that neutrons are the most abundant component among extensive air shower hadrons. However, multiple neutrons which appear with long delays in neutron monitors nearby the EAS core ('neutron thunder') are mostly not the neutrons of the shower, but have a secondary origin. The bulk of them is produced by high energy EAS hadrons hitting the monitors. The delays are due to the termalization and diffusion of neutrons in the moderator and reflector of the monitor accompanied by the production of secondary gamma-quanta. This conclusion raises the important problem of the interaction of EAS with the ground, the stuff of the detectors and their environment since they have often hydrogen containing materials like polyethilene in neutron monitors. Such interaction can give an additional contribution to the signal in the EAS detectors. It can be particularly important for the signals from scintillator or water tank detectors at km-long distances from the EAS core where neutrons of the shower become the dominant component after a few mcsec behind the EAS front.
[ { "created": "Mon, 22 Jan 2007 11:15:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Erlykin", "A. D.", "" ] ]
Simulations show that neutrons are the most abundant component among extensive air shower hadrons. However, multiple neutrons which appear with long delays in neutron monitors nearby the EAS core ('neutron thunder') are mostly not the neutrons of the shower, but have a secondary origin. The bulk of them is produced by high energy EAS hadrons hitting the monitors. The delays are due to the termalization and diffusion of neutrons in the moderator and reflector of the monitor accompanied by the production of secondary gamma-quanta. This conclusion raises the important problem of the interaction of EAS with the ground, the stuff of the detectors and their environment since they have often hydrogen containing materials like polyethilene in neutron monitors. Such interaction can give an additional contribution to the signal in the EAS detectors. It can be particularly important for the signals from scintillator or water tank detectors at km-long distances from the EAS core where neutrons of the shower become the dominant component after a few mcsec behind the EAS front.
hep-ph/0407108
Barbara Mele
Giancarlo Ferrera, Barbara Mele
Higgs-boson coupling to charginos in the MSSM at linear colliders
9 pages, 6 figures, Proceedings, IFAE Conference, Torino, April 14-16,2004
null
null
null
hep-ph
null
We discuss the associated production of a light Higgs boson and a light chargino pair in the process e+e- -> h chi+ chi- in the Minimal Supersymmetric Standard Model (MSSM) at linear colliders (LC) with \sqrt s=500 GeV. This process gives direct informations about the Higgs-boson coupling to light charginos, that cannot be analyzed in decay processes due to phase-space restrictions. We compute total cross sections in the regions of the MSSM parameter space where the process cannot proceed via on-shell production and subsequent decay of either heavier charginos or pseudoscalar Higgs bosons A. Cross sections up to a few 0.1 fb are allowed, making this process potentially detectable at high-luminosity linear colliders. We also compute analytically the final h momentum distributions in the limit of very heavy electron-sneutrino masses.
[ { "created": "Fri, 9 Jul 2004 09:12:30 GMT", "version": "v1" } ]
2016-09-06
[ [ "Ferrera", "Giancarlo", "" ], [ "Mele", "Barbara", "" ] ]
We discuss the associated production of a light Higgs boson and a light chargino pair in the process e+e- -> h chi+ chi- in the Minimal Supersymmetric Standard Model (MSSM) at linear colliders (LC) with \sqrt s=500 GeV. This process gives direct informations about the Higgs-boson coupling to light charginos, that cannot be analyzed in decay processes due to phase-space restrictions. We compute total cross sections in the regions of the MSSM parameter space where the process cannot proceed via on-shell production and subsequent decay of either heavier charginos or pseudoscalar Higgs bosons A. Cross sections up to a few 0.1 fb are allowed, making this process potentially detectable at high-luminosity linear colliders. We also compute analytically the final h momentum distributions in the limit of very heavy electron-sneutrino masses.
hep-ph/9606443
Thomas Teubner
E. M. Levin (LAFEX, Brazil), A. D. Martin (Centre for Particle Theory, Durham), M. G. Ryskin (Nucl. Phys. Inst., Petersburg) and T. Teubner (CPT, Durham)
Diffractive open charm production at HERA
34 pages, LaTeX, 15 Postscript figures included using epsf. The complete paper, including figures, is also available via anonymous ftp at ftp://cpt1.dur.ac.uk/pub/preprints/dtp96/dtp9650/
Z.Phys. C74 (1997) 671-685
null
DTP/96/50
hep-ph
null
We use perturbative QCD to calculate the cross sections $\sigma^{L,T}$ for the diffractive production of open charm $(c\overline{c})$ from longitudinally and transversely polarised photons (of virtuality $Q^2$) incident at high energy $(\sqrt{s})$ on a proton target. We study both the $Q^2$ and $M^2$ dependence of the cross sections, where $M$ is the invariant mass of the $c\overline{c}$ pair. Surprisingly, the result for $\sigma^T$, as well as for $\sigma^L$, is perturbatively stable. We estimate higher-order corrections and find a sizeable enhancement of the cross sections. The cross sections depend on the {\it square} of the gluon density $g (x, K^2)$, and we show that the observation of open charm at the HERA electron-proton collider can act as a sensitive probe of the gluon distribution for $x = (Q^2 + M^2)/s$ and scale $K^2 = (m_c^2 + \langle k_T^2 \rangle) (1 + Q^2/M^2)$ where the average quark transverse momentum squared $\langle k_T^2 \rangle \sim m_c^2$. As compared to diffractive $J/\psi$ production, open charm has the advantage that it is independent of the non-perturbative ambiguities arising from the $J/\psi$ wave function. We estimate the fraction of diffractive events that arise from $c\overline{c}$ production.
[ { "created": "Wed, 26 Jun 1996 14:15:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Levin", "E. M.", "", "LAFEX, Brazil" ], [ "Martin", "A. D.", "", "Centre for Particle Theory,\n Durham" ], [ "Ryskin", "M. G.", "", "Nucl. Phys. Inst., Petersburg" ], [ "Teubner", "T.", "", "CPT,\n Durham" ] ]
We use perturbative QCD to calculate the cross sections $\sigma^{L,T}$ for the diffractive production of open charm $(c\overline{c})$ from longitudinally and transversely polarised photons (of virtuality $Q^2$) incident at high energy $(\sqrt{s})$ on a proton target. We study both the $Q^2$ and $M^2$ dependence of the cross sections, where $M$ is the invariant mass of the $c\overline{c}$ pair. Surprisingly, the result for $\sigma^T$, as well as for $\sigma^L$, is perturbatively stable. We estimate higher-order corrections and find a sizeable enhancement of the cross sections. The cross sections depend on the {\it square} of the gluon density $g (x, K^2)$, and we show that the observation of open charm at the HERA electron-proton collider can act as a sensitive probe of the gluon distribution for $x = (Q^2 + M^2)/s$ and scale $K^2 = (m_c^2 + \langle k_T^2 \rangle) (1 + Q^2/M^2)$ where the average quark transverse momentum squared $\langle k_T^2 \rangle \sim m_c^2$. As compared to diffractive $J/\psi$ production, open charm has the advantage that it is independent of the non-perturbative ambiguities arising from the $J/\psi$ wave function. We estimate the fraction of diffractive events that arise from $c\overline{c}$ production.
2001.01736
Saul Ramos-Sanchez
Hans Peter Nilles, Saul Ramos-Sanchez and Patrick K.S. Vaudrevange
Eclectic Flavor Groups
23 pages, 2 tables; v2: interpretation of outer automorphisms clarified
null
10.1007/JHEP02(2020)045
TUM-HEP 1247/19
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The simultaneous study of top-down and bottom-up approaches to modular flavor symmetry leads necessarily to the concept of eclectic flavor groups. These are nontrivial products of modular and traditional flavor symmetries that exhibit the phenomenon of local flavor enhancement in moduli space. We develop methods to determine the eclectic flavor groups that can be consistently associated with a given traditional flavor symmetry. Applying these methods to a large family of prominent traditional flavor symmetries, we try to identify potential candidates for realistic eclectic flavor groups and show that they are relatively rare. Model building with finite modular flavor symmetries thus appears to be much more restrictive than previously thought.
[ { "created": "Mon, 6 Jan 2020 19:00:36 GMT", "version": "v1" }, { "created": "Tue, 14 Jan 2020 15:26:50 GMT", "version": "v2" } ]
2020-03-18
[ [ "Nilles", "Hans Peter", "" ], [ "Ramos-Sanchez", "Saul", "" ], [ "Vaudrevange", "Patrick K. S.", "" ] ]
The simultaneous study of top-down and bottom-up approaches to modular flavor symmetry leads necessarily to the concept of eclectic flavor groups. These are nontrivial products of modular and traditional flavor symmetries that exhibit the phenomenon of local flavor enhancement in moduli space. We develop methods to determine the eclectic flavor groups that can be consistently associated with a given traditional flavor symmetry. Applying these methods to a large family of prominent traditional flavor symmetries, we try to identify potential candidates for realistic eclectic flavor groups and show that they are relatively rare. Model building with finite modular flavor symmetries thus appears to be much more restrictive than previously thought.
1906.11297
Junichiro Kawamura
Junichiro Kawamura, Stuart Raby and Andreas Trautner
Complete Vector-like Fourth Family and new $\mathrm{U(1)^\prime}$ for Muon Anomalies
40 pages, 2 figures and 14 tables; Figure 2 replaced, references added
Phys. Rev. D 100, 055030 (2019)
10.1103/PhysRevD.100.055030
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the Standard Model (SM) with the addition of a $\mathrm{U(1)^\prime}$ gauge symmetry and a complete fourth family of quarks and leptons which are vector-like with respect to the full $\mathrm{SU(3)_C}\times \mathrm{SU(2)_L} \times \mathrm{U(1)_Y}\times \mathrm{U(1)^\prime}$ gauge symmetry. The model provides a unified explanation of experimental anomalies in $(g - 2)_\mu$ as well as $b \rightarrow s \ell^+ \ell^-$ decays. We find good fits to the deviations from the SM, while at the same time fitting all other SM observables. The model includes a new $Z^\prime$ gauge boson, a $\mathrm{U(1)^\prime}$-breaking scalar, and vector-like leptons all with mass of order a few $100$ GeV. It is consistent with all currently released high energy experimental data, however, it appears imminently testable with well designed future searches. Also precision flavor experiments, especially more accurate direct determinations of CKM matrix elements, would allow to probe the best fit points.
[ { "created": "Wed, 26 Jun 2019 19:00:20 GMT", "version": "v1" }, { "created": "Sun, 7 Jul 2019 14:25:29 GMT", "version": "v2" } ]
2019-09-25
[ [ "Kawamura", "Junichiro", "" ], [ "Raby", "Stuart", "" ], [ "Trautner", "Andreas", "" ] ]
We consider the Standard Model (SM) with the addition of a $\mathrm{U(1)^\prime}$ gauge symmetry and a complete fourth family of quarks and leptons which are vector-like with respect to the full $\mathrm{SU(3)_C}\times \mathrm{SU(2)_L} \times \mathrm{U(1)_Y}\times \mathrm{U(1)^\prime}$ gauge symmetry. The model provides a unified explanation of experimental anomalies in $(g - 2)_\mu$ as well as $b \rightarrow s \ell^+ \ell^-$ decays. We find good fits to the deviations from the SM, while at the same time fitting all other SM observables. The model includes a new $Z^\prime$ gauge boson, a $\mathrm{U(1)^\prime}$-breaking scalar, and vector-like leptons all with mass of order a few $100$ GeV. It is consistent with all currently released high energy experimental data, however, it appears imminently testable with well designed future searches. Also precision flavor experiments, especially more accurate direct determinations of CKM matrix elements, would allow to probe the best fit points.
hep-ph/0209082
Alexandros Kehagias
George Triantaphyllou
Understanding the genesis of mass: a mystery pointing towards the mirror world
17 PDF pages
null
null
NTUA 04/02
hep-ph hep-ex physics.pop-ph
null
We give a pedagogical and concise presentation of dynamical mass generation involving strongly-interacting mirror fermions. As a paradigm which has been explicitly shown to predict correctly the weak scale and the weak angle and thus addressing successfully the essence of the hierarchy problem of energy scales (contrary to "supersymmetric" or "extra-dimension" models) and the unification of fundamental forces, it might have already manifested indirectly its validity experimentally, as first noted by the author in 1998, via the bottom-quark forward-backward asymmetry and the related coupling parameter A_b. After a decade during which the particle-physics community was frequently misled by a particularly obscurantist interpretation of the L.E.P./S.L.C. precision data, this approach emerges as a strong candidate for new physics beyond the standard model of elementary particles to be thoroughly tested in the forthcoming high-energy experiments.
[ { "created": "Sat, 7 Sep 2002 07:34:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Triantaphyllou", "George", "" ] ]
We give a pedagogical and concise presentation of dynamical mass generation involving strongly-interacting mirror fermions. As a paradigm which has been explicitly shown to predict correctly the weak scale and the weak angle and thus addressing successfully the essence of the hierarchy problem of energy scales (contrary to "supersymmetric" or "extra-dimension" models) and the unification of fundamental forces, it might have already manifested indirectly its validity experimentally, as first noted by the author in 1998, via the bottom-quark forward-backward asymmetry and the related coupling parameter A_b. After a decade during which the particle-physics community was frequently misled by a particularly obscurantist interpretation of the L.E.P./S.L.C. precision data, this approach emerges as a strong candidate for new physics beyond the standard model of elementary particles to be thoroughly tested in the forthcoming high-energy experiments.
2207.14809
Sven Heinemeyer
S. Heinemeyer
CDF Measurement of $M_W$: Theory implications
8 pages, 5 figures. Invited plenary talk at the 20th FPCP conference, Oxford, MS, 2022. Partially based on arXiv:2203.15710 and arXiv:2204.05975
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
The CDF collaboration recently reported a measurement of the $W$-bosos mass, $M_W$, showing a large positive deviation from the Standard Model (SM) prediction. The question arises whether extensions of the SM exist that can accommodate such large values, and what further phenomenological consequences arise from this. We give a brief review of the implications of the new CDF measurement on the SM, as well as on Higgs-sector extensions. In particular, we review the compatibility of the $M_W$ measurement of CDF with excesses observed in the light Higgs-boson searches at $\sim 95$ GeV, as well as with the Minimal Supersymmetric Standard Model in conjunction with the anomalous magnetic moment of the muon, $(g-2)_\mu$.
[ { "created": "Fri, 29 Jul 2022 17:56:32 GMT", "version": "v1" } ]
2022-08-01
[ [ "Heinemeyer", "S.", "" ] ]
The CDF collaboration recently reported a measurement of the $W$-bosos mass, $M_W$, showing a large positive deviation from the Standard Model (SM) prediction. The question arises whether extensions of the SM exist that can accommodate such large values, and what further phenomenological consequences arise from this. We give a brief review of the implications of the new CDF measurement on the SM, as well as on Higgs-sector extensions. In particular, we review the compatibility of the $M_W$ measurement of CDF with excesses observed in the light Higgs-boson searches at $\sim 95$ GeV, as well as with the Minimal Supersymmetric Standard Model in conjunction with the anomalous magnetic moment of the muon, $(g-2)_\mu$.
0910.5706
Steen Hannestad
Steen Hannestad, Jan Hamann, Alessandro Mirizzi, Georg G. Raffelt, Yvonne Y.Y. Wong
Cosmological axion bounds
4 pages, 2 figures, To appear in the proceedings of 5th Patras Workshop on Axions, WIMPs and WISPs, Durham 13-17 July 2009
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss current cosmological constraints on axions, as well as future sensitivities. Bounds on axion hot dark matter are discussed first, and subsequently we discuss both current and future sensitivity to models in which axions play the role as cold dark matter, but where the Peccei-Quinn symmetry is not restored during reheating.
[ { "created": "Thu, 29 Oct 2009 18:59:46 GMT", "version": "v1" } ]
2009-11-02
[ [ "Hannestad", "Steen", "" ], [ "Hamann", "Jan", "" ], [ "Mirizzi", "Alessandro", "" ], [ "Raffelt", "Georg G.", "" ], [ "Wong", "Yvonne Y. Y.", "" ] ]
We discuss current cosmological constraints on axions, as well as future sensitivities. Bounds on axion hot dark matter are discussed first, and subsequently we discuss both current and future sensitivity to models in which axions play the role as cold dark matter, but where the Peccei-Quinn symmetry is not restored during reheating.