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1111.5422
Jubin Park
Jubin Park and Sin Kyu Kang
Weak Mixing Angle and Higgs Mass in Gauge-Higgs Unification Models with Brane Kinetic Terms
22 pages, 4 figures
null
10.1007/JHEP04(2012)101
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the idea of Gauge-Higgs unification(GHU) can be rescued from the constraint of weak mixing angle by introducing localized brane kinetic terms in higher dimensional GHU models with bulk and simple gauge groups. We find that those terms lead to a ratio between Higgs and W boson masses, which is a little bit deviated from the one derived in the standard model. From numerical analysis, we find that the current lower bound on the Higgs mass tends to prefer to exceptional groups E(6), E(7), E(8) rather than other groups like SU(3l), SO(2n+1), G(2), and F(4) in 6-dimensional(D) GHU models irrespective of the compactification scales. For the compactification scale below 1 TeV, the Higgs masses in 6D GHU models with SU(3l), SO(2n+1), G(2), and F(4) groups are predicted to be less than the current lower bound unless a model parameter responsible for re-scaling SU(2) gauge coupling is taken to be unnaturally large enough. To see how the situation is changed in more higher dimensional GHU model, we take 7D S^{3}/ Z_{2} and 8D T^{4}/ Z_{2} models. It turns out from our numerical analysis that these higher dimensional GHU models with gauge groups except for E(6) can lead to the Higgs boson whose masses are predicted to be above the current lower bound only for the compatification scale above 1 TeV without taking unnaturally large value of the model parameter, whereas the Higgs masses in the GHU models with E(6) are compatible with the current lower bound even for the compatification scale below 1 TeV.
[ { "created": "Wed, 23 Nov 2011 07:34:16 GMT", "version": "v1" } ]
2015-06-03
[ [ "Park", "Jubin", "" ], [ "Kang", "Sin Kyu", "" ] ]
We show that the idea of Gauge-Higgs unification(GHU) can be rescued from the constraint of weak mixing angle by introducing localized brane kinetic terms in higher dimensional GHU models with bulk and simple gauge groups. We find that those terms lead to a ratio between Higgs and W boson masses, which is a little bit deviated from the one derived in the standard model. From numerical analysis, we find that the current lower bound on the Higgs mass tends to prefer to exceptional groups E(6), E(7), E(8) rather than other groups like SU(3l), SO(2n+1), G(2), and F(4) in 6-dimensional(D) GHU models irrespective of the compactification scales. For the compactification scale below 1 TeV, the Higgs masses in 6D GHU models with SU(3l), SO(2n+1), G(2), and F(4) groups are predicted to be less than the current lower bound unless a model parameter responsible for re-scaling SU(2) gauge coupling is taken to be unnaturally large enough. To see how the situation is changed in more higher dimensional GHU model, we take 7D S^{3}/ Z_{2} and 8D T^{4}/ Z_{2} models. It turns out from our numerical analysis that these higher dimensional GHU models with gauge groups except for E(6) can lead to the Higgs boson whose masses are predicted to be above the current lower bound only for the compatification scale above 1 TeV without taking unnaturally large value of the model parameter, whereas the Higgs masses in the GHU models with E(6) are compatible with the current lower bound even for the compatification scale below 1 TeV.
hep-ph/0605005
Boris Kayser
Boris Kayser
The Neutrino Future -- Comments Honoring Gustavo Branco
7 pages. Presented at Symposium in Honor of Gustavo Branco, Lisbon, Portugal, July 2005
null
null
null
hep-ph
null
We briefly report on a study intended to help shape the future of neutrino physics -- an area to which Professor Gustavo Branco has made distinguished contributions.
[ { "created": "Mon, 1 May 2006 16:14:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kayser", "Boris", "" ] ]
We briefly report on a study intended to help shape the future of neutrino physics -- an area to which Professor Gustavo Branco has made distinguished contributions.
2305.11855
Ipsita Ray
Ipsita Ray, Soumitra Nandi
Test of new physics effects in $\bar{B} \to (D^{(*)}, \pi) \ell^-\bar{\nu}_{\ell}$ decays with heavy and light leptons
Version accepted for publication in JHEP
null
null
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $\bar{B}\to D(D^*) \ell^-\bar{\nu}_{\ell}$ decays based on the up-to-date available inputs from experiments and the lattice. First, we review the standard model (SM) predictions of the different observables associated with these decay channels. In the analyses, we consider new physics (NP) effects in the channels with the heavy ($\tau$), as well as the light leptons ($\mu, e$). We have extracted $|V_{cb}|$ along with the new physics Wilson coefficients (WCs) from the available data on light leptons; the extracted value of $|V_{cb}|$ is $(40.3 \pm 0.5)\times 10^{-3}$. The extracted WCs are zero consistent, but some could be of order $10^{-2}$. Also, we have done the simultaneous analysis of the data in $\bar{B} \to D^{(*)}(\mu^-,e^-)\bar{\nu}$ alongside the inputs on $R(D^{(*)}) = \frac{\Gamma(\bar{B}\to D^{(*)}\tau^-\bar{\nu}_{\tau})}{\Gamma(\bar{B}\to D^{(*)}\ell^-\bar{\nu}_{\ell})}$ and the $D^*$ longitudinal polarisation fraction $F_L^{D^*}$ in different NP scenarios and extracted $|V_{cb}|$ which is consistent with the number mentioned above. Also, the simultaneous explanation of $R(D^{(*)})$ and $F_L^{D^*}$ is not possible in the one-operator scenarios. However, the two operator scenarios with $\mathcal{O}_{S_2}^{\tau} = (\bar{q}_R b_L)(\bar{\tau}_R\nu_{\tau L})$ as one of the operators could explain all these three measurements. Finally, we have given predictions of all the related observables in $\bar{B} \to D^{(*)}(\tau^-,\mu^-,e^-)\bar{\nu}$ decays in the NP scenarios, which could be tested in future experiments. We have repeated this exercise for $\bar{B} \to \pi\ell^-\bar{\nu}_{\ell}$ decays with the light lepton and extracted $|V_{ub}|$ and the new WCs. Finally, using all these available data for the light and heavy leptons, we have given bounds on the couplings of the relevant SM effective field theory (SMEFT) operators and the probable NP scale $\Lambda$.
[ { "created": "Fri, 19 May 2023 17:46:02 GMT", "version": "v1" }, { "created": "Thu, 22 Jun 2023 18:45:24 GMT", "version": "v2" }, { "created": "Thu, 21 Dec 2023 11:49:37 GMT", "version": "v3" } ]
2023-12-22
[ [ "Ray", "Ipsita", "" ], [ "Nandi", "Soumitra", "" ] ]
We study the $\bar{B}\to D(D^*) \ell^-\bar{\nu}_{\ell}$ decays based on the up-to-date available inputs from experiments and the lattice. First, we review the standard model (SM) predictions of the different observables associated with these decay channels. In the analyses, we consider new physics (NP) effects in the channels with the heavy ($\tau$), as well as the light leptons ($\mu, e$). We have extracted $|V_{cb}|$ along with the new physics Wilson coefficients (WCs) from the available data on light leptons; the extracted value of $|V_{cb}|$ is $(40.3 \pm 0.5)\times 10^{-3}$. The extracted WCs are zero consistent, but some could be of order $10^{-2}$. Also, we have done the simultaneous analysis of the data in $\bar{B} \to D^{(*)}(\mu^-,e^-)\bar{\nu}$ alongside the inputs on $R(D^{(*)}) = \frac{\Gamma(\bar{B}\to D^{(*)}\tau^-\bar{\nu}_{\tau})}{\Gamma(\bar{B}\to D^{(*)}\ell^-\bar{\nu}_{\ell})}$ and the $D^*$ longitudinal polarisation fraction $F_L^{D^*}$ in different NP scenarios and extracted $|V_{cb}|$ which is consistent with the number mentioned above. Also, the simultaneous explanation of $R(D^{(*)})$ and $F_L^{D^*}$ is not possible in the one-operator scenarios. However, the two operator scenarios with $\mathcal{O}_{S_2}^{\tau} = (\bar{q}_R b_L)(\bar{\tau}_R\nu_{\tau L})$ as one of the operators could explain all these three measurements. Finally, we have given predictions of all the related observables in $\bar{B} \to D^{(*)}(\tau^-,\mu^-,e^-)\bar{\nu}$ decays in the NP scenarios, which could be tested in future experiments. We have repeated this exercise for $\bar{B} \to \pi\ell^-\bar{\nu}_{\ell}$ decays with the light lepton and extracted $|V_{ub}|$ and the new WCs. Finally, using all these available data for the light and heavy leptons, we have given bounds on the couplings of the relevant SM effective field theory (SMEFT) operators and the probable NP scale $\Lambda$.
1412.1002
C. A. de S. Pires
C. A. de S. Pires
Neutrino mass mechanisms in 3-3-1 models: A short review
Final version with corrections on the tex and references updated. Published in the Physics International 2015. arXiv admin note: text overlap with arXiv:0903.0370
null
10.3844/pisp.2015.33.41
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we review some mechanisms that provide light neutrinos in the framework of 3-3-1 gauge models without exotic leptons. In regard to the minimal 3-3-1 model, we call the attention to the fact that the perturbative regime of the model goes until 5 TeV. This requires alternative mechanisms in order to generate light neutrinos. In this review we discuss two mechanisms capable of generating light neutrinos in the framework of the minimal 3-3-1 model. In regard to the 3-3-1 model with right-handed neutrinos, we call the attention to the fact that in it mechanisms that generate light left-handed neutrinos also generate light right-handed neutrinos. Finally, we call the attention to the fact that the 3-3-1 model with right-handed neutrinos accommodate naturally the inverse seesaw mechanism.
[ { "created": "Tue, 2 Dec 2014 18:16:26 GMT", "version": "v1" }, { "created": "Wed, 3 Dec 2014 18:17:55 GMT", "version": "v2" }, { "created": "Wed, 23 Sep 2015 14:23:51 GMT", "version": "v3" } ]
2015-09-24
[ [ "Pires", "C. A. de S.", "" ] ]
In this paper we review some mechanisms that provide light neutrinos in the framework of 3-3-1 gauge models without exotic leptons. In regard to the minimal 3-3-1 model, we call the attention to the fact that the perturbative regime of the model goes until 5 TeV. This requires alternative mechanisms in order to generate light neutrinos. In this review we discuss two mechanisms capable of generating light neutrinos in the framework of the minimal 3-3-1 model. In regard to the 3-3-1 model with right-handed neutrinos, we call the attention to the fact that in it mechanisms that generate light left-handed neutrinos also generate light right-handed neutrinos. Finally, we call the attention to the fact that the 3-3-1 model with right-handed neutrinos accommodate naturally the inverse seesaw mechanism.
0911.0806
Xu-Hao Yuan
Xu-Hao Yuan, Liang Tang
Fermion correction to the mass of the scalar glueball in QCD sum rule
5 pages, 2 figures
Commun. Theor. Phys. 54:495-498, 2010
10.1088/0253-6102/54/3/23
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Contributions of fermions to the mass of the scalar glueball $0^{++}$ are calculated at two-loop level in the framework of QCD sum rules. It obviously changes the coefficients in the operator product expansion (OPE) and shifts the mass of glueball.
[ { "created": "Wed, 4 Nov 2009 12:41:32 GMT", "version": "v1" } ]
2011-03-28
[ [ "Yuan", "Xu-Hao", "" ], [ "Tang", "Liang", "" ] ]
Contributions of fermions to the mass of the scalar glueball $0^{++}$ are calculated at two-loop level in the framework of QCD sum rules. It obviously changes the coefficients in the operator product expansion (OPE) and shifts the mass of glueball.
2106.00940
Vineet Kumar Dr.
Vineet Kumar, Kinkar Saha, Prashant Shukla, Abhijit Bhattacharyya
Bottomonia production in p+p collisions under NRQCD formalism
null
Nuclear Physics A 1013 (2021) 122226
10.1016/j.nuclphysa.2021.122226
null
hep-ph hep-ex hep-lat nucl-th
http://creativecommons.org/licenses/by/4.0/
In this work, we present the calculation of the production cross sections of bottomonia states using Non-Relativistic Quantum Chromodynamics (NRQCD) formalism. The direct production cross-section of a resonance can be factorised in terms of short distance Quantum Chromodynamics (QCD) cross sections and long distance matrix elements (LDMEs) under NRQCD. We use a large set of measured $\Upsilon$(nS) production data at Tevatron and LHC energies in both central and forward rapidity regions to extract the LDMEs with better precision. The feed down contributions from the higher states including the $\chi_{b}$(3P) state are taken into account for the LDME extraction. The formalism provides a good description of the bottomonia data in wide transverse momentum range at different collision energies.
[ { "created": "Wed, 2 Jun 2021 04:59:11 GMT", "version": "v1" } ]
2021-06-30
[ [ "Kumar", "Vineet", "" ], [ "Saha", "Kinkar", "" ], [ "Shukla", "Prashant", "" ], [ "Bhattacharyya", "Abhijit", "" ] ]
In this work, we present the calculation of the production cross sections of bottomonia states using Non-Relativistic Quantum Chromodynamics (NRQCD) formalism. The direct production cross-section of a resonance can be factorised in terms of short distance Quantum Chromodynamics (QCD) cross sections and long distance matrix elements (LDMEs) under NRQCD. We use a large set of measured $\Upsilon$(nS) production data at Tevatron and LHC energies in both central and forward rapidity regions to extract the LDMEs with better precision. The feed down contributions from the higher states including the $\chi_{b}$(3P) state are taken into account for the LDME extraction. The formalism provides a good description of the bottomonia data in wide transverse momentum range at different collision energies.
1911.10148
Tista Mukherjee
Tista Mukherjee, Madhurima Pandey, Debasish Majumdar and Ashadul Halder
Estimation of Baryon Asymmetry from Dark Matter Decaying into IceCube Neutrinos
25 pages, 7 figures
International Journal of Modern Physics A, Vol. 36, No. 13, 2150078 (2021)
10.1142/S0217751X21500780
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent results of IceCube Neutrino Observatory include an excess of PeV neutrino events which appear to follow a broken power law different from the other lower energy neutrinos detected by IceCube. The possible astrophysical source of these neutrinos is still unknown. One possible source of such neutrinos could be the decay of non-thermal, long-living heavy mass Dark Matter, whose mass should be $> 10^{6} \rm {GeV}$ and could have produced at the very early Universe. They can undergo cascading decay via both hadronic and leptonic channels to finally produce such high energy neutrinos. This possibility has been explored in this work by studying the decay flux of these Dark Matter candidates. The mass and lifetime of such Dark Matter particles have been obtained by performing a $\chi^2$ fit with the PeV neutrino data of IceCube. We finally estimate the baryon asymmetry produced in the Universe due to such Dark Matter decay.
[ { "created": "Fri, 22 Nov 2019 17:14:16 GMT", "version": "v1" }, { "created": "Mon, 25 Nov 2019 07:30:48 GMT", "version": "v2" }, { "created": "Wed, 4 Dec 2019 11:07:51 GMT", "version": "v3" }, { "created": "Thu, 27 May 2021 12:32:27 GMT", "version": "v4" } ]
2021-05-28
[ [ "Mukherjee", "Tista", "" ], [ "Pandey", "Madhurima", "" ], [ "Majumdar", "Debasish", "" ], [ "Halder", "Ashadul", "" ] ]
The recent results of IceCube Neutrino Observatory include an excess of PeV neutrino events which appear to follow a broken power law different from the other lower energy neutrinos detected by IceCube. The possible astrophysical source of these neutrinos is still unknown. One possible source of such neutrinos could be the decay of non-thermal, long-living heavy mass Dark Matter, whose mass should be $> 10^{6} \rm {GeV}$ and could have produced at the very early Universe. They can undergo cascading decay via both hadronic and leptonic channels to finally produce such high energy neutrinos. This possibility has been explored in this work by studying the decay flux of these Dark Matter candidates. The mass and lifetime of such Dark Matter particles have been obtained by performing a $\chi^2$ fit with the PeV neutrino data of IceCube. We finally estimate the baryon asymmetry produced in the Universe due to such Dark Matter decay.
hep-ph/9504376
92006
Yen-Chung Lin
Prediction of the anomalous magnetic moment of nucleon from the nucleon anomaly
7 pages,Latex, no figures
Phys.Lett. B354 (1995) 470-472
10.1016/0370-2693(95)00673-9
null
hep-ph
null
We construct the effective anomaly lagrangian involving nucleons and photons by using current-current coupling method. The contribution of this lagrangian to the anomalous magnetic moment of nucleon is purely isovector. The anomalous magnetic moment of proton, $\kappa_P$, can be calculated from the this lagrangian and it is found to be $\kappa_P^{Theor.} = 1.77$, which is in excellent agreement with the experimental value $\kappa_P^{Exp.} = 1.79$. While the case of neutron, $\kappa_N^{Theor.} = -2.58$ as compared to $\kappa_N^{Exp.} =-1.91$, is less satisfactory, but the sign is correct.
[ { "created": "Mon, 24 Apr 1995 14:28:59 GMT", "version": "v1" } ]
2015-06-25
[ [ "Lin", "Yen-Chung", "" ] ]
We construct the effective anomaly lagrangian involving nucleons and photons by using current-current coupling method. The contribution of this lagrangian to the anomalous magnetic moment of nucleon is purely isovector. The anomalous magnetic moment of proton, $\kappa_P$, can be calculated from the this lagrangian and it is found to be $\kappa_P^{Theor.} = 1.77$, which is in excellent agreement with the experimental value $\kappa_P^{Exp.} = 1.79$. While the case of neutron, $\kappa_N^{Theor.} = -2.58$ as compared to $\kappa_N^{Exp.} =-1.91$, is less satisfactory, but the sign is correct.
hep-ph/0605299
Chuan Hung Chen
Chuan-Hung Chen and Chao-Qiang Geng
Lepton flavor violation in $\tau$ decays
11 pages, 3 figures, typos corrected, references added, version to fit journal
Phys.Rev.D74:035010,2006
10.1103/PhysRevD.74.035010
null
hep-ph hep-ex
null
We study the lepton flavor violation (LFV) in tau decays in the framework of the supersymmetric seesaw mechanism with nonholomorphic terms for the lepton sector at a large $\tan\beta$. In particular, we analyze two new decay modes $\tau\to \ell f_0(980)$ and $\tau\to \ell K^{+} K^{-}$ arising from the scalar boson exchanges contrast to $\tau\to \ell\eta^{(\prime)}$ from the pseudoscalar ones. We find that the decay branching ratios of the two new modes could be not only as large as the current upper limits of $O(10^{-7})$, but also larger than those of $\tau\to \ell \eta^{(\prime)}$. Experimental searches for the two modes are important for the LFV induced by the scalar-mediated mechanism. In addition, we show that the decay branching ratios of $\tau\to \ell \mu^{+} \mu^{-}$ are related to those of $\tau\to \ell \eta$ and $\tau\to \ell f_0(980)$.
[ { "created": "Sat, 27 May 2006 10:37:36 GMT", "version": "v1" }, { "created": "Wed, 7 Jun 2006 06:53:51 GMT", "version": "v2" }, { "created": "Wed, 9 Aug 2006 15:55:22 GMT", "version": "v3" }, { "created": "Wed, 23 Aug 2006 15:11:03 GMT", "version": "v4" } ]
2008-11-26
[ [ "Chen", "Chuan-Hung", "" ], [ "Geng", "Chao-Qiang", "" ] ]
We study the lepton flavor violation (LFV) in tau decays in the framework of the supersymmetric seesaw mechanism with nonholomorphic terms for the lepton sector at a large $\tan\beta$. In particular, we analyze two new decay modes $\tau\to \ell f_0(980)$ and $\tau\to \ell K^{+} K^{-}$ arising from the scalar boson exchanges contrast to $\tau\to \ell\eta^{(\prime)}$ from the pseudoscalar ones. We find that the decay branching ratios of the two new modes could be not only as large as the current upper limits of $O(10^{-7})$, but also larger than those of $\tau\to \ell \eta^{(\prime)}$. Experimental searches for the two modes are important for the LFV induced by the scalar-mediated mechanism. In addition, we show that the decay branching ratios of $\tau\to \ell \mu^{+} \mu^{-}$ are related to those of $\tau\to \ell \eta$ and $\tau\to \ell f_0(980)$.
hep-ph/0302115
Reinosa
Urko Reinosa
Resummation in hot field theories
5 pages, 3 figures, contribution to the conference Strong and Electroweak Matter (SEWM2002), Heidelberg, Germany, October 2-5, 2002
null
10.1142/9789812704498_0060
T03/016
hep-ph
null
We consider a scalar theory at finite temperature in the 2PI resummation scheme, including phi^3 and phi^4 interactions. Already at the one loop level in this scheme, we have to deal with a non local approximation. We carry out the renormalization and obtain finite equations for the propagator. Within this model we can explore the effect of non local contributions to the self-energy in the evaluation of thermodynamic quantities.
[ { "created": "Fri, 14 Feb 2003 15:59:12 GMT", "version": "v1" } ]
2017-08-23
[ [ "Reinosa", "Urko", "" ] ]
We consider a scalar theory at finite temperature in the 2PI resummation scheme, including phi^3 and phi^4 interactions. Already at the one loop level in this scheme, we have to deal with a non local approximation. We carry out the renormalization and obtain finite equations for the propagator. Within this model we can explore the effect of non local contributions to the self-energy in the evaluation of thermodynamic quantities.
1311.4889
George T. Fleming
T. Appelquist (1), R. C. Brower (2), M. I. Buchoff (3), M. Cheng (4), G. T. Fleming (1), J. Kiskis (5), M. F. Lin (6), E. T. Neil (7 and 8), J. C. Osborn (9), C. Rebbi (2), D. Schaich (10), C. Schroeder (11), S. Syritsyn (8), G. Voronov (1), P. Vranas (11), O. Witzel (4) ((1) Yale University, (2) Boston University, (3) INT Seattle WA, (4) Center for Computational Science, Boston University, (5) UC Davis, (6) Computational Science Center, BNL, (7) UC Boulder, (8) RIKEN-BNL Research Center, BNL, (9) Argonne Leadership Computing Facility, ANL, (10) Syracuse University, (11) LLNL)
Two-Color Theory with Novel Infrared Behavior
six pages, 4 figures
Phys. Rev. Lett. 112, 111601 (2014)
10.1103/PhysRevLett.112.111601
null
hep-ph hep-lat
http://creativecommons.org/licenses/publicdomain/
Using lattice simulations, we study the infrared behavior of a particularly interesting SU(2) gauge theory, with six massless Dirac fermions in the fundamental representation. We compute the running gauge coupling derived non-perturbatively from the Schrodinger functional of the theory, finding no evidence for an infrared fixed point up through gauge couplings of order 20. This implies that the theory either is governed in the infrared by a fixed point of considerable strength, unseen so far in non-supersymmetric gauge theories, or breaks its global chiral symmetries producing a large number of composite Nambu-Goldstone bosons relative to the number of underlying degrees of freedom. Thus either of these phases exhibits novel behavior.
[ { "created": "Tue, 19 Nov 2013 21:00:24 GMT", "version": "v1" } ]
2014-03-26
[ [ "Appelquist", "T.", "", "7 and 8" ], [ "Brower", "R. C.", "", "7 and 8" ], [ "Buchoff", "M. I.", "", "7 and 8" ], [ "Cheng", "M.", "", "7 and 8" ], [ "Fleming", "G. T.", "", "7 and 8" ], [ "Kiskis", "J.", ...
Using lattice simulations, we study the infrared behavior of a particularly interesting SU(2) gauge theory, with six massless Dirac fermions in the fundamental representation. We compute the running gauge coupling derived non-perturbatively from the Schrodinger functional of the theory, finding no evidence for an infrared fixed point up through gauge couplings of order 20. This implies that the theory either is governed in the infrared by a fixed point of considerable strength, unseen so far in non-supersymmetric gauge theories, or breaks its global chiral symmetries producing a large number of composite Nambu-Goldstone bosons relative to the number of underlying degrees of freedom. Thus either of these phases exhibits novel behavior.
hep-ph/0207218
Sergio Scopetta
S. Scopetta and V. Vento
Generalized parton distributions and constituent quarks
4 pages, 4 eps figures; Contribution to the European Workshop on the QCD Structure of the Nucleon (QCD-N'02), Ferrara, Italy, 3-6 Apr 2002
Nucl.Phys. A711 (2002) 190-193
10.1016/S0375-9474(02)01214-9
null
hep-ph
null
An approach is described to calculate Generalized Parton Distributions (GPDs) in Constituent Quark Models (CQM). The GPDs are obtained from wave functions to be evaluated in a given CQM. The general relations linking the twist-two GPDs to the form factors and to the leading twist quark densities are recovered. Results for the leading twist, unpolarized GPD in the Isgur and Karl model are presented.
[ { "created": "Thu, 18 Jul 2002 09:34:12 GMT", "version": "v1" } ]
2009-11-07
[ [ "Scopetta", "S.", "" ], [ "Vento", "V.", "" ] ]
An approach is described to calculate Generalized Parton Distributions (GPDs) in Constituent Quark Models (CQM). The GPDs are obtained from wave functions to be evaluated in a given CQM. The general relations linking the twist-two GPDs to the form factors and to the leading twist quark densities are recovered. Results for the leading twist, unpolarized GPD in the Isgur and Karl model are presented.
2304.03704
V\'ictor Mart\'inez-Fern\'andez
K. Deja, V. Martinez-Fernandez, B. Pire, P. Sznajder and J. Wagner
Prospects for GPDs extraction with Double DVCS
5 pages, 4 figures, proceedings for the XXIX Cracow Epiphany Conference
null
null
CPHT-PC013.032023
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Double deeply virtual Compton scattering (DDVCS) is the process where an electron scatters off a nucleon and produces a lepton pair. The main advantage of this process in contrast with deeply virtual and timelike Compton scatterings (DVCS and TCS) is the possibility of directly measuring GPDs for $x\neq\pm\xi$ at leading order in $\alpha_s$ (LO). We present a new calculation of the DDVCS amplitude based on the methods developed by R. Kleiss and W. J. Stirling in the 1980s. These techniques produce expressions for amplitudes that are perfectly suited for implementation in numerical simulations. Via the PARTONS software, the correctness of this new formulation has been tested by comparing the DVCS and TCS limits of DDVCS with independent calculations of DVCS and TCS.
[ { "created": "Fri, 7 Apr 2023 15:40:32 GMT", "version": "v1" } ]
2023-04-11
[ [ "Deja", "K.", "" ], [ "Martinez-Fernandez", "V.", "" ], [ "Pire", "B.", "" ], [ "Sznajder", "P.", "" ], [ "Wagner", "J.", "" ] ]
Double deeply virtual Compton scattering (DDVCS) is the process where an electron scatters off a nucleon and produces a lepton pair. The main advantage of this process in contrast with deeply virtual and timelike Compton scatterings (DVCS and TCS) is the possibility of directly measuring GPDs for $x\neq\pm\xi$ at leading order in $\alpha_s$ (LO). We present a new calculation of the DDVCS amplitude based on the methods developed by R. Kleiss and W. J. Stirling in the 1980s. These techniques produce expressions for amplitudes that are perfectly suited for implementation in numerical simulations. Via the PARTONS software, the correctness of this new formulation has been tested by comparing the DVCS and TCS limits of DDVCS with independent calculations of DVCS and TCS.
2112.03355
Daniel Sadasivan
Daniel Sadasivan, Andrei Alexandru, Hakan Akdag, Felipe Amorim, Ruair\'i Brett, Chris Culver, Michael D\"oring, Frank X. Lee, and Maxim Mai
Pole position of the $a_1(1260)$ resonance in a three-body unitary framework
17 pages, 13 figures
null
10.1103/PhysRevD.105.054020
null
hep-ph nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Masses, widths, and branching ratios of hadronic resonances are quantified by their pole positions and residues with respect to transition amplitudes on the Riemann sheets of the complex energy-plane. In this study we discuss the analytic structure in the physical energy region of three-body scattering amplitudes on such manifolds. As an application, we determine the pole position of the $a_1(1260)$ meson from the ALEPH experiment by allowing for $\pi\rho$ coupled channels in S- and D-wave. We find it to be $\sqrt{s_0}=(1232^{+15+9}_{-0-11}-i266^{+0+15}_{-22-27})~\text{MeV}$.
[ { "created": "Mon, 6 Dec 2021 21:01:36 GMT", "version": "v1" }, { "created": "Mon, 28 Feb 2022 21:47:07 GMT", "version": "v2" } ]
2022-04-06
[ [ "Sadasivan", "Daniel", "" ], [ "Alexandru", "Andrei", "" ], [ "Akdag", "Hakan", "" ], [ "Amorim", "Felipe", "" ], [ "Brett", "Ruairí", "" ], [ "Culver", "Chris", "" ], [ "Döring", "Michael", "" ], [ ...
Masses, widths, and branching ratios of hadronic resonances are quantified by their pole positions and residues with respect to transition amplitudes on the Riemann sheets of the complex energy-plane. In this study we discuss the analytic structure in the physical energy region of three-body scattering amplitudes on such manifolds. As an application, we determine the pole position of the $a_1(1260)$ meson from the ALEPH experiment by allowing for $\pi\rho$ coupled channels in S- and D-wave. We find it to be $\sqrt{s_0}=(1232^{+15+9}_{-0-11}-i266^{+0+15}_{-22-27})~\text{MeV}$.
hep-ph/0411012
Seung Woo Ham
S.W. Ham, S.K. OH, D. Son
Electroweak phase transition in the MSSM with four generations
12 pages, 2 tables, 2 figures
Phys.Rev. D71 (2005) 015001
10.1103/PhysRevD.71.015001
null
hep-ph
null
By assuming the existence of the sequential fourth generation to the minimal supersymmetric standard model (MSSM), we study the possibility of a strongly first-order electroweak phase transition. We find that there is a parameter region of the MSSM where the electroweak phase transition is strongly first order. In that parameter region, the mass of the lighter scalar Higgs boson is calculated to be above the experimental lower bound, and the scalar quarks of the third and the fourth generations are heavier than the corresponding quarks.
[ { "created": "Sun, 31 Oct 2004 21:15:43 GMT", "version": "v1" }, { "created": "Mon, 20 Dec 2004 01:08:17 GMT", "version": "v2" } ]
2009-11-10
[ [ "Ham", "S. W.", "" ], [ "OH", "S. K.", "" ], [ "Son", "D.", "" ] ]
By assuming the existence of the sequential fourth generation to the minimal supersymmetric standard model (MSSM), we study the possibility of a strongly first-order electroweak phase transition. We find that there is a parameter region of the MSSM where the electroweak phase transition is strongly first order. In that parameter region, the mass of the lighter scalar Higgs boson is calculated to be above the experimental lower bound, and the scalar quarks of the third and the fourth generations are heavier than the corresponding quarks.
hep-ph/9907274
null
H. Kleinert, B. Van den Bossche
No Spontaneous Breakdown of Chiral Symmetry in Nambu-Jona-Lasinio Model
Contains a number of improvements. Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of paper also at http://www.physik.fu-berlin.de/~kleinert/291
Phys.Lett. B474 (2000) 336-346
10.1016/S0370-2693(00)00056-3
null
hep-ph hep-th nucl-th
null
We argue that the spontaneous breakdown of symmetry in the chirally symmetric Nambu--Jona-Lasinio model which was supposed to illustrate the origin of the low mass of pions in hadron physics does not occur due to strong fluctuations in the sigma - pi field space. Although quarks acquire a constituent mass, sigma and pi turn out to have equal heavy masses of the order of the constituent quark mass.
[ { "created": "Thu, 8 Jul 1999 03:54:41 GMT", "version": "v1" }, { "created": "Fri, 11 Feb 2000 11:45:48 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kleinert", "H.", "" ], [ "Bossche", "B. Van den", "" ] ]
We argue that the spontaneous breakdown of symmetry in the chirally symmetric Nambu--Jona-Lasinio model which was supposed to illustrate the origin of the low mass of pions in hadron physics does not occur due to strong fluctuations in the sigma - pi field space. Although quarks acquire a constituent mass, sigma and pi turn out to have equal heavy masses of the order of the constituent quark mass.
1208.0917
Eduardo Souza Fraga
Eduardo S. Fraga
Thermal chiral and deconfining transitions in the presence of a magnetic background
22 pages, 8 figures, to appear in Lect. Notes Phys. "Strongly interacting matter in magnetic fields" (Springer), edited by D. Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Yee
null
10.1007/978-3-642-37305-3_5
null
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the influence of a magnetic background on the phase diagram of strong interactions and how the chiral and deconfining transitions can be affected. First we summarize results for both transitions obtained in the framework of the linear sigma model coupled to quarks and to the Polyakov loop, and how they compare to other effective model approaches and to lattice QCD. Then we discuss the outcome of the magnetic MIT bag model that yields a behavior for the critical deconfining temperature which is compatible with recent lattice results and magnetic catalysis. The qualitative success of the magnetic MIT bag model hints to $T_{c}$ being a confinement-driven quantity, and leads us to the discussion of its behavior as predicted within the large-$N_{c}$ limit of QCD, which is also in line with the most recent lattice QCD results provided that quarks behave paramagnetically.
[ { "created": "Sat, 4 Aug 2012 12:27:22 GMT", "version": "v1" } ]
2015-06-11
[ [ "Fraga", "Eduardo S.", "" ] ]
We review the influence of a magnetic background on the phase diagram of strong interactions and how the chiral and deconfining transitions can be affected. First we summarize results for both transitions obtained in the framework of the linear sigma model coupled to quarks and to the Polyakov loop, and how they compare to other effective model approaches and to lattice QCD. Then we discuss the outcome of the magnetic MIT bag model that yields a behavior for the critical deconfining temperature which is compatible with recent lattice results and magnetic catalysis. The qualitative success of the magnetic MIT bag model hints to $T_{c}$ being a confinement-driven quantity, and leads us to the discussion of its behavior as predicted within the large-$N_{c}$ limit of QCD, which is also in line with the most recent lattice QCD results provided that quarks behave paramagnetically.
1603.06692
Inna Aznauryan
I. G. Aznauryan and V. D. Burkert
Configuration mixings and light-front relativistic quark model predictions for the electroexcitation of the Delta(1232)3/2+, N(1440)1/2+, and Delta(1600)3/2+
4 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the impact of the configurations mixings that follow from QCD-inspired interquark forces on our results for the electroexcitation of the Delta(1232)3/2+, N(1440)1/2+, and Delta(1600)3/2+ obtained earlier in the light-front relativistic quark model. We have shown that the configurations mixings increase the 3q contribution to the gamma* N -> Delta(1232)3/2+ magnetic-dipole form factor at Q2=0 from 42% to 63% and significantly improve the agreement with experiment for the gamma* p -> N(1440)1/2+ transverse helicity amplitude at Q2 > 1.5GeV2. For the gamma* N -> Delta(1600)3/2+ transition, configuration mixings change strongly the results obtained earlier for the N and Delta(1600)3/2+ taken as pure states in the multiplets [56,0+] and [56',0+].
[ { "created": "Tue, 22 Mar 2016 07:28:06 GMT", "version": "v1" } ]
2016-03-23
[ [ "Aznauryan", "I. G.", "" ], [ "Burkert", "V. D.", "" ] ]
We investigate the impact of the configurations mixings that follow from QCD-inspired interquark forces on our results for the electroexcitation of the Delta(1232)3/2+, N(1440)1/2+, and Delta(1600)3/2+ obtained earlier in the light-front relativistic quark model. We have shown that the configurations mixings increase the 3q contribution to the gamma* N -> Delta(1232)3/2+ magnetic-dipole form factor at Q2=0 from 42% to 63% and significantly improve the agreement with experiment for the gamma* p -> N(1440)1/2+ transverse helicity amplitude at Q2 > 1.5GeV2. For the gamma* N -> Delta(1600)3/2+ transition, configuration mixings change strongly the results obtained earlier for the N and Delta(1600)3/2+ taken as pure states in the multiplets [56,0+] and [56',0+].
hep-ph/9509365
Rachel Jeannerot
Rachel Jeannerot
A Supersymmetric SO(10) Model with Inflation and Cosmic Strings
32 pages, uses RevTex. Misprint in a reference
Phys.Rev. D53 (1996) 5426-5436
10.1103/PhysRevD.53.5426
DAMTP-95-35
hep-ph astro-ph
null
We have built a supersymmetric SO(10) model consistent with cosmological observations. The model gives rise to a false vacuum hybrid inflationary scenario which solves the monopole problem. We argue that this type of inflationary scenario is generic in supersymmetric SO(10) model, and arises naturally from the theory. Neither any external field nor any external symmetry has to be added. It can just be a consequence of the theory. In our specific model, at the end of inflation, cosmic strings form. The properties of the strings are presented. The cosmic background radiation anisotropies induced by the inflationary perturbations and the cosmic strings are estimated. The model produces a stable lightest superparticle and a very light left-handed neutrino which may serve as the cold and hot dark matter. The properties of a mixed cosmic string-inflationary large scale structure formation scenario are discussed.
[ { "created": "Fri, 22 Sep 1995 13:13:00 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 1995 19:12:20 GMT", "version": "v2" } ]
2009-10-28
[ [ "Jeannerot", "Rachel", "" ] ]
We have built a supersymmetric SO(10) model consistent with cosmological observations. The model gives rise to a false vacuum hybrid inflationary scenario which solves the monopole problem. We argue that this type of inflationary scenario is generic in supersymmetric SO(10) model, and arises naturally from the theory. Neither any external field nor any external symmetry has to be added. It can just be a consequence of the theory. In our specific model, at the end of inflation, cosmic strings form. The properties of the strings are presented. The cosmic background radiation anisotropies induced by the inflationary perturbations and the cosmic strings are estimated. The model produces a stable lightest superparticle and a very light left-handed neutrino which may serve as the cold and hot dark matter. The properties of a mixed cosmic string-inflationary large scale structure formation scenario are discussed.
hep-ph/9507228
Kiselev
V.V.Kiselev
Hard-soft factorization in B_c--> psi pi decay
8 pages, LATEX file
Phys.Lett.B372:326-330,1996
10.1016/0370-2693(96)00073-1
IHEP 95-80, Protvino, Russia
hep-ph
null
The width of $B_c^+\to \psi \pi^+$ decay is calculated in the framework of factorization of a hard gluon exchange and a soft binding of quarks in the heavy quarkonium, so that ${\rm BR}(B_c^+\to \psi \pi^+) = 2.0\pm 0.5$ \%.
[ { "created": "Wed, 5 Jul 1995 16:03:25 GMT", "version": "v1" }, { "created": "Thu, 6 Jul 1995 14:45:23 GMT", "version": "v2" } ]
2014-11-17
[ [ "Kiselev", "V. V.", "" ] ]
The width of $B_c^+\to \psi \pi^+$ decay is calculated in the framework of factorization of a hard gluon exchange and a soft binding of quarks in the heavy quarkonium, so that ${\rm BR}(B_c^+\to \psi \pi^+) = 2.0\pm 0.5$ \%.
1605.05749
Marco Chianese Mr
Marco Chianese
IceCube PeV Neutrinos and Leptophilic Dark Matter
5 pages, 1 figure. Prepared for the proceedings of the conference TAUP 2015
null
10.1088/1742-6596/718/4/042014
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the scenario where the IceCube high energy neutrino events are explained in terms of an extraterrestrial flux due to two different components: a contribution coming from know astrophysical sources for energies up to few hundreds TeV and a top-down contribution originated by the decay of heavy dark matter particles with a mass of few PeV. Contrary to previous approaches, we consider a leptophilic three-body decay that dominates at PeV energies due to the absence of quarks in the final state. We find that the theoretical predictions of such a scenario are in a slightly better agreement with the IceCube data if the astrophysical component has a cut-off at about 100 TeV. This interpretation of IceCube data can be easily tested in the near future since the decaying dark matter scenario predicts a sharp cut-off at PeV energy scale and the observation of an anisotropy towards Galactic Center of our Galaxy in contrast with the isotropic astrophysical flux.
[ { "created": "Wed, 18 May 2016 20:19:44 GMT", "version": "v1" } ]
2016-06-22
[ [ "Chianese", "Marco", "" ] ]
We analyze the scenario where the IceCube high energy neutrino events are explained in terms of an extraterrestrial flux due to two different components: a contribution coming from know astrophysical sources for energies up to few hundreds TeV and a top-down contribution originated by the decay of heavy dark matter particles with a mass of few PeV. Contrary to previous approaches, we consider a leptophilic three-body decay that dominates at PeV energies due to the absence of quarks in the final state. We find that the theoretical predictions of such a scenario are in a slightly better agreement with the IceCube data if the astrophysical component has a cut-off at about 100 TeV. This interpretation of IceCube data can be easily tested in the near future since the decaying dark matter scenario predicts a sharp cut-off at PeV energy scale and the observation of an anisotropy towards Galactic Center of our Galaxy in contrast with the isotropic astrophysical flux.
hep-ph/9410295
Laurence Yaffe
Laurence Yaffe
The Electroweak Phase Transition, Part 2: $\epsilon$-Expansion Results
9 pages, 2 figures
null
null
null
hep-ph
null
Talk presented at the conference Quarks `94: Vladimir, Russia. I summarize the application of $\epsilon$-expansion methods to the electroweak phase transition. Results from both leading and next-to-leading order calculations are discussed.
[ { "created": "Fri, 14 Oct 1994 23:51:56 GMT", "version": "v1" } ]
2009-09-25
[ [ "Yaffe", "Laurence", "" ] ]
Talk presented at the conference Quarks `94: Vladimir, Russia. I summarize the application of $\epsilon$-expansion methods to the electroweak phase transition. Results from both leading and next-to-leading order calculations are discussed.
1503.02586
Andrey Shkerin
Andrey Shkerin and Sergey Sibiryakov
On stability of electroweak vacuum during inflation
9 pages, 2 figures, dependence of the grav. corrections to the bounce action on non-minimal coupling updated, corresponding references added
Phys. Lett. B 746 (2015) 257-260
10.1016/j.physletb.2015.05.012
CERN-PH-TH-2015-043, INR-TH/2015-008
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study Coleman-De Luccia tunneling of the Standard Model Higgs field during inflation in the case when the electroweak vacuum is metastable. We verify that the tunneling rate is exponentially suppressed. The main contribution to the suppression is the same as in flat space-time. We analytically estimate the corrections due to the expansion of the universe and an effective mass term in the Higgs potential that can be present at inflation.
[ { "created": "Fri, 6 Mar 2015 18:08:34 GMT", "version": "v1" }, { "created": "Fri, 29 May 2015 12:45:08 GMT", "version": "v2" }, { "created": "Thu, 1 Dec 2016 08:53:08 GMT", "version": "v3" } ]
2016-12-02
[ [ "Shkerin", "Andrey", "" ], [ "Sibiryakov", "Sergey", "" ] ]
We study Coleman-De Luccia tunneling of the Standard Model Higgs field during inflation in the case when the electroweak vacuum is metastable. We verify that the tunneling rate is exponentially suppressed. The main contribution to the suppression is the same as in flat space-time. We analytically estimate the corrections due to the expansion of the universe and an effective mass term in the Higgs potential that can be present at inflation.
hep-ph/0608070
Carlo Giunti
Carlo Giunti
Neutrino Flavor States and the Quantum Theory of Neutrino Oscillations
20 pages; final version, to be published as a Topical Review in Journal of Physics G: Nuclear and Particle Physics
J.Phys. G34 (2007) R93-R109
10.1088/0954-3899/34/2/R02
null
hep-ph astro-ph hep-ex hep-th
null
The definition and derivation of flavor neutrino states in the framework of standard Quantum Field Theory is reviewed, clarifying some subtle points. It is shown that a flavor neutrino state that describes a neutrino produced or detected in a charged-current weak interaction process depends on the process under consideration and is appropriate for the description of neutrino oscillations as well as for the calculation of neutrino production or detection rates. Hence, we have a consistent framework for the description of neutrino oscillations and interactions in neutrino oscillation experiments. The standard flavor neutrino states are obtained as approximations which describe neutrinos in experiments that are not sensitive to the dependence of neutrino interactions on the neutrino mass differences. It is also shown that the oscillation probability can be derived either through the usual light-ray time = distance approximation or through an average of the space-time dependent oscillation probability over the unobserved propagation time.
[ { "created": "Mon, 7 Aug 2006 14:53:32 GMT", "version": "v1" }, { "created": "Thu, 23 Nov 2006 13:29:07 GMT", "version": "v2" } ]
2009-11-11
[ [ "Giunti", "Carlo", "" ] ]
The definition and derivation of flavor neutrino states in the framework of standard Quantum Field Theory is reviewed, clarifying some subtle points. It is shown that a flavor neutrino state that describes a neutrino produced or detected in a charged-current weak interaction process depends on the process under consideration and is appropriate for the description of neutrino oscillations as well as for the calculation of neutrino production or detection rates. Hence, we have a consistent framework for the description of neutrino oscillations and interactions in neutrino oscillation experiments. The standard flavor neutrino states are obtained as approximations which describe neutrinos in experiments that are not sensitive to the dependence of neutrino interactions on the neutrino mass differences. It is also shown that the oscillation probability can be derived either through the usual light-ray time = distance approximation or through an average of the space-time dependent oscillation probability over the unobserved propagation time.
0712.2693
Gautam Bhattacharyya
Gautam Bhattacharyya, Gustavo C. Branco, S. Nandi
Universal Doublet-Singlet Higgs Couplings and phenomenology at the CERN Large Hadron Collider
5 pages, no figures; v2: normalisations settled, results unchanged, References added; v3: a new section 'Deviation from universality' added, version to appear in Phys Rev D (Brief Reports section)
Phys.Rev.D77:117701,2008
10.1103/PhysRevD.77.117701
CERN-PH-TH/2007-264, OSU/HEP/07-07, SINP/TNP/07-33
hep-ph
null
We consider a minimal extension of the standard model where a real, gauge singlet scalar field is added to the standard spectrum. Introducing the Ansatz of universality of scalar couplings, we are led to a scenario which has a set of very distinctive and testable predictions: (i) the mixing between the standard model Higgs and the new state is near maximal, (ii) the ratio of the two Higgs mass eigenstates is fixed ($\sim \sqrt{3}$), (iii) the decay modes of each of the two eigenstates are standard model like. We also study how electroweak precision tests constrain this scenario. We predict the lighter Higgs to lie in the range of 114 and 145 GeV, and hence the heavier one between 198 and 250 GeV. The predictions of the model can be tested at the upcoming LHC.
[ { "created": "Mon, 17 Dec 2007 13:34:44 GMT", "version": "v1" }, { "created": "Mon, 21 Jan 2008 06:30:25 GMT", "version": "v2" }, { "created": "Tue, 3 Jun 2008 13:42:26 GMT", "version": "v3" } ]
2008-11-26
[ [ "Bhattacharyya", "Gautam", "" ], [ "Branco", "Gustavo C.", "" ], [ "Nandi", "S.", "" ] ]
We consider a minimal extension of the standard model where a real, gauge singlet scalar field is added to the standard spectrum. Introducing the Ansatz of universality of scalar couplings, we are led to a scenario which has a set of very distinctive and testable predictions: (i) the mixing between the standard model Higgs and the new state is near maximal, (ii) the ratio of the two Higgs mass eigenstates is fixed ($\sim \sqrt{3}$), (iii) the decay modes of each of the two eigenstates are standard model like. We also study how electroweak precision tests constrain this scenario. We predict the lighter Higgs to lie in the range of 114 and 145 GeV, and hence the heavier one between 198 and 250 GeV. The predictions of the model can be tested at the upcoming LHC.
1112.3702
Ning Liu
Ning Liu
QCD corrections to the production of $t\bar{t}\gamma$ at the ILC
12 pages, 5 figures, version acceptd by Phys. Lett. B
null
10.1016/j.physletb.2011.12.032
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A precise calculation of the top quark pair production associated with a hard photon is essential for testing the electroweak property of the top quark in the Standard Model (SM). We investigate the one-loop QCD corrections to the process $e^{+}e^{-} \to t\bar{t}\gamma$ at the International Linear Collider (ILC), and find that the $K$-factor can be as large as 1.238 (1.105, 1.060) for a center-of-mass energy $\sqrt{s}=500 (800, 1500)$ GeV. The transverse momentum distributions of the top quark and photon are respectively shown at leading order (LO) and next-to-leading order(NLO). Due to the asymmetric rapidity distribution of the top (anti-top) quark, we also study the top quark forward-backward asymmetry ($A^{t}_{FB}$) in $t\bar{t}\gamma$ production at NLO, which is found to be 45.82 (55.25, 55.89)% for $\sqrt{s}=500 (800, 1500)$ GeV.
[ { "created": "Fri, 16 Dec 2011 02:06:28 GMT", "version": "v1" } ]
2015-06-03
[ [ "Liu", "Ning", "" ] ]
A precise calculation of the top quark pair production associated with a hard photon is essential for testing the electroweak property of the top quark in the Standard Model (SM). We investigate the one-loop QCD corrections to the process $e^{+}e^{-} \to t\bar{t}\gamma$ at the International Linear Collider (ILC), and find that the $K$-factor can be as large as 1.238 (1.105, 1.060) for a center-of-mass energy $\sqrt{s}=500 (800, 1500)$ GeV. The transverse momentum distributions of the top quark and photon are respectively shown at leading order (LO) and next-to-leading order(NLO). Due to the asymmetric rapidity distribution of the top (anti-top) quark, we also study the top quark forward-backward asymmetry ($A^{t}_{FB}$) in $t\bar{t}\gamma$ production at NLO, which is found to be 45.82 (55.25, 55.89)% for $\sqrt{s}=500 (800, 1500)$ GeV.
hep-ph/0411239
Koji Tsumura
S. Kanemura, K. Matsuda, H. Nakano, T. Ota, T. Shindou, E. Takasugi and K. Tsumura
Bi-maximal mixing at GUT, the low energy data and the leptogenesis
Talk given by E. Takasugi at NuFact04, Osaka, Japan, July 26 - August 1,2004 - 3 pages, 4 figures
null
10.1016/j.nuclphysbps.2005.05.067
null
hep-ph
null
In the framework of the minimum supersymmetric model with right-handed neutrinos, we consider the Bi-maximal mixing which is realized at the GUT scale and discuss a question that this model can reproduce the low energy phenomena and the leptogenesis.
[ { "created": "Thu, 18 Nov 2004 09:13:20 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kanemura", "S.", "" ], [ "Matsuda", "K.", "" ], [ "Nakano", "H.", "" ], [ "Ota", "T.", "" ], [ "Shindou", "T.", "" ], [ "Takasugi", "E.", "" ], [ "Tsumura", "K.", "" ] ]
In the framework of the minimum supersymmetric model with right-handed neutrinos, we consider the Bi-maximal mixing which is realized at the GUT scale and discuss a question that this model can reproduce the low energy phenomena and the leptogenesis.
hep-ph/9411418
Robert Harlander
J.H. K\"uhn and E. Mirkes
Semileptonic tau decays, structure functions, kinematics and polarisation
12 pages, LaTeX (uses epsf.sty, 3 ps-figures appended as extra uuencoded file) The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ttp94-27/ttp94-27.ps, or via www at http://ttpux2.physik.uni-karlsruhe.de/preprints.html
Nucl.Phys.Proc.Suppl.40:181-189,1995
10.1016/0920-5632(95)00143-W
TTP94-27
hep-ph
null
The most general angular distribution of two or three meson final states from semileptonic decays $\tau\rightarrow \pi\pi\nu$, $K\pi\nu$, $\pi\pi\pi\nu$, $K\pi\pi\nu$, $K\pi\nu$, $KKK\nu$, $\eta\pi\pi\nu,\,\ldots{}$ of polarized $\tau$ leptons can be characterized by 16 structure functions. Predictions for hadronic matrix elements, based on CVC and chiral Lagrangians and their relations to the structure functions are discussed. Most of them can be determined in currently ongoing high statistics experiments. Emphasis of the kinematical analysis is firstly put on $\tau$ decays in $e^{+}e^{-}$ experiments where the neutrino escapes detection and the $\tau$ rest frame cannot be reconstructed. Subsequently it is shown, how the determination of hadron tracks in double semileptonic events allows to fully reconstruct the $\tau$ kinematics. The implications for the spin analysis are indicated.
[ { "created": "Tue, 29 Nov 1994 09:03:52 GMT", "version": "v1" } ]
2011-07-19
[ [ "Kühn", "J. H.", "" ], [ "Mirkes", "E.", "" ] ]
The most general angular distribution of two or three meson final states from semileptonic decays $\tau\rightarrow \pi\pi\nu$, $K\pi\nu$, $\pi\pi\pi\nu$, $K\pi\pi\nu$, $K\pi\nu$, $KKK\nu$, $\eta\pi\pi\nu,\,\ldots{}$ of polarized $\tau$ leptons can be characterized by 16 structure functions. Predictions for hadronic matrix elements, based on CVC and chiral Lagrangians and their relations to the structure functions are discussed. Most of them can be determined in currently ongoing high statistics experiments. Emphasis of the kinematical analysis is firstly put on $\tau$ decays in $e^{+}e^{-}$ experiments where the neutrino escapes detection and the $\tau$ rest frame cannot be reconstructed. Subsequently it is shown, how the determination of hadron tracks in double semileptonic events allows to fully reconstruct the $\tau$ kinematics. The implications for the spin analysis are indicated.
hep-ph/0203213
Yuri V. Kovchegov
Yuri V. Kovchegov, Kirill L. Tuchin (University of Washington)
Elliptic Flow from Minijet Production in Heavy Ion Collisions
21 pages, 4 figures, LaTeX, v1-3: some discussion and references added; v4: journal version
Nucl.Phys. A708 (2002) 413-434
10.1016/S0375-9474(02)01023-0
NT@UW-02-005, INT-PUB-02-32
hep-ph hep-ex nucl-ex nucl-th
null
We calculate the contribution to the elliptic flow observable v2 from two-particle correlations in minijet production in ultrarelativistic heavy ion collisions. We use a minijet production cross section derived in a model inspired by saturation approach to high energy scattering. Resulting differential elliptic flow v2(pT) is an increasing function of pT for transverse momenta below the saturation scale Qs. At higher transverse momenta (pT > Qs) differential flow stops growing and becomes approximately constant, reproducing the elliptic flow saturation data reported by STAR. The centrality dependence of the minijet contribution to v2 is also in good agreement with the data.
[ { "created": "Fri, 22 Mar 2002 03:52:47 GMT", "version": "v1" }, { "created": "Tue, 2 Apr 2002 20:47:28 GMT", "version": "v2" }, { "created": "Thu, 16 May 2002 22:10:38 GMT", "version": "v3" }, { "created": "Fri, 7 Jun 2002 20:07:35 GMT", "version": "v4" } ]
2015-06-25
[ [ "Kovchegov", "Yuri V.", "", "University of Washington" ], [ "Tuchin", "Kirill L.", "", "University of Washington" ] ]
We calculate the contribution to the elliptic flow observable v2 from two-particle correlations in minijet production in ultrarelativistic heavy ion collisions. We use a minijet production cross section derived in a model inspired by saturation approach to high energy scattering. Resulting differential elliptic flow v2(pT) is an increasing function of pT for transverse momenta below the saturation scale Qs. At higher transverse momenta (pT > Qs) differential flow stops growing and becomes approximately constant, reproducing the elliptic flow saturation data reported by STAR. The centrality dependence of the minijet contribution to v2 is also in good agreement with the data.
2210.01132
Sudhakantha Girmohanta
Sudhakantha Girmohanta and Robert Shrock
Fitting a Self-Interacting Dark Matter Model to Data Ranging From Satellite Galaxies to Galaxy Clusters
9 pages, 8 figures, matches the publication in Phys. Rev. D
Phys. Rev. D 107, 063006 (2023)
10.1103/PhysRevD.107.063006
Stony Brook preprint YITP-SB-2022-32
hep-ph astro-ph.CO astro-ph.GA hep-ex hep-th
http://creativecommons.org/licenses/by/4.0/
We present a fit to observational data in an asymmetric self-interacting dark matter model using our recently calculated cross sections that incorporate both $t$-channel and $u$-channel exchanges in the scattering of identical particles. We find good fits to the data ranging from dwarf galaxies to galaxy clusters, and equivalent relative velocities from $\sim 20$ km/sec to $\gtrsim 10^3$ km/s. We compare our results with previous fits that used only $t$-channel exchange contributions to the scattering.
[ { "created": "Mon, 3 Oct 2022 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 14 Feb 2023 15:22:48 GMT", "version": "v2" } ]
2023-03-09
[ [ "Girmohanta", "Sudhakantha", "" ], [ "Shrock", "Robert", "" ] ]
We present a fit to observational data in an asymmetric self-interacting dark matter model using our recently calculated cross sections that incorporate both $t$-channel and $u$-channel exchanges in the scattering of identical particles. We find good fits to the data ranging from dwarf galaxies to galaxy clusters, and equivalent relative velocities from $\sim 20$ km/sec to $\gtrsim 10^3$ km/s. We compare our results with previous fits that used only $t$-channel exchange contributions to the scattering.
1502.04043
Jue Zhang
Jue Zhang
Confronting Four Zero Neutrino Yukawa Textures with $N_2^{}$-dominated Leptogenesis
28 pages, 5 figures; v2: references added, minor changes, the version to appear in Phys. Rev. D; v3: references added and updated
Phys. Rev. D 91, 073012 (2015)
10.1103/PhysRevD.91.073012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a restricted Type-I seesaw scenario with four texture zeros in the neutrino Yukawa matrix, in the weak basis where both the charged-lepton Yukawa matrix and the Majorana mass matrix for right-handed neutrinos are diagonal and real. Inspired by grand unified theories, we further require the neutrino Yukawa matrix to exhibit a similar hierarchical pattern to that in the up-type quark Yukawa matrix. With such a hierarchy requirement, we find that leptogenesis, which would operate in a $N_2^{}$-dominated scenario with the asymmetry generated by the next-to-lightest right-handed neutrino $N_2^{}$, can greatly reduce the number of allowed textures, and disfavors the scenario that three light neutrinos are quasi-degenerate. Such a quasi-degenerate scenario of light neutrinos may soon be tested in upcoming neutrino experiments.
[ { "created": "Fri, 13 Feb 2015 16:10:34 GMT", "version": "v1" }, { "created": "Fri, 10 Apr 2015 11:14:46 GMT", "version": "v2" }, { "created": "Thu, 17 Sep 2015 02:20:48 GMT", "version": "v3" } ]
2015-09-18
[ [ "Zhang", "Jue", "" ] ]
We consider a restricted Type-I seesaw scenario with four texture zeros in the neutrino Yukawa matrix, in the weak basis where both the charged-lepton Yukawa matrix and the Majorana mass matrix for right-handed neutrinos are diagonal and real. Inspired by grand unified theories, we further require the neutrino Yukawa matrix to exhibit a similar hierarchical pattern to that in the up-type quark Yukawa matrix. With such a hierarchy requirement, we find that leptogenesis, which would operate in a $N_2^{}$-dominated scenario with the asymmetry generated by the next-to-lightest right-handed neutrino $N_2^{}$, can greatly reduce the number of allowed textures, and disfavors the scenario that three light neutrinos are quasi-degenerate. Such a quasi-degenerate scenario of light neutrinos may soon be tested in upcoming neutrino experiments.
hep-ph/9708464
Jon Pumplin
Jon Pumplin
Hard underlying event correction to inclusive jet cross sections
19 pages, revtex, 8 PostScript figures
Phys. Rev. D 57, 5787 (1998)
10.1103/PhysRevD.57.5787
MSU-HEP-70826
hep-ph
null
Jets observed in hadron-hadron scattering contain a contribution from the underlying event that is produced by spectator interactions taking place incoherently with the major parton-parton collision, due to the extended composite structure of the colliding hadrons. Using a recent measurement of the double parton interaction rate, we calculate that the underlying event may be 2 - 3 times stronger than generally assumed, as a result of semi-hard perturbative multiple-parton interactions. This can have an important influence on the inclusive jet cross section at moderate values of E_T, persisting at the 5 - 10% level to the largest observable E_T. We show how the underlying event can be measured accurately using a generalization of the method first proposed by Marchesini and Webber.
[ { "created": "Tue, 26 Aug 1997 16:25:16 GMT", "version": "v1" } ]
2016-08-25
[ [ "Pumplin", "Jon", "" ] ]
Jets observed in hadron-hadron scattering contain a contribution from the underlying event that is produced by spectator interactions taking place incoherently with the major parton-parton collision, due to the extended composite structure of the colliding hadrons. Using a recent measurement of the double parton interaction rate, we calculate that the underlying event may be 2 - 3 times stronger than generally assumed, as a result of semi-hard perturbative multiple-parton interactions. This can have an important influence on the inclusive jet cross section at moderate values of E_T, persisting at the 5 - 10% level to the largest observable E_T. We show how the underlying event can be measured accurately using a generalization of the method first proposed by Marchesini and Webber.
1108.2266
Jan Pribis
Boris Kostenko and Jan Pribi\v{s}
On possibility to observe chiral phase transition in separate fragments of dense baryon matter
null
null
10.1134/S1063778812070046
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Density fluctuations of intranuclear matter suffering collisions with projectile particles are capable to turn into multiquark clusters with chiral symmetry restored. Theoretical analysis of these processes requires an additional taking account of finite size effects in the region of the chiral phase transition. From the experimental point of view, this method of observation of the chiral phase transition has its inherent advantages due to a relatively moderate number of secondary particles to be registered.
[ { "created": "Wed, 10 Aug 2011 19:56:04 GMT", "version": "v1" } ]
2015-05-30
[ [ "Kostenko", "Boris", "" ], [ "Pribiš", "Jan", "" ] ]
Density fluctuations of intranuclear matter suffering collisions with projectile particles are capable to turn into multiquark clusters with chiral symmetry restored. Theoretical analysis of these processes requires an additional taking account of finite size effects in the region of the chiral phase transition. From the experimental point of view, this method of observation of the chiral phase transition has its inherent advantages due to a relatively moderate number of secondary particles to be registered.
hep-ph/0601194
M\'arcio Jos\'e Menon
R.F. Avila and M.J. Menon
Extended Derivative Dispersion Relations
7 pages, 1 figure, contribution to "Sense of Beauty in Physics", Miniconference in Honor of Adriano Di Giacomo on his 70th Birthday, Pisa, Italy, Jan. 26-27, 2006
null
10.1590/S0103-97332007000400035
null
hep-ph
null
It is shown that, for a wide class of functions with physical interest as forward scattering amplitudes, integral dispersion relations can be replaced by derivative forms without any high-energy approximation. The applicability of these extended derivative relations, in the investigation of forward proton-proton and antiproton-proton elastic scattering, is exemplified by means of a Pomeron-Reggeon model with totally nondegenerate trajectories.
[ { "created": "Tue, 24 Jan 2006 11:13:16 GMT", "version": "v1" } ]
2015-06-25
[ [ "Avila", "R. F.", "" ], [ "Menon", "M. J.", "" ] ]
It is shown that, for a wide class of functions with physical interest as forward scattering amplitudes, integral dispersion relations can be replaced by derivative forms without any high-energy approximation. The applicability of these extended derivative relations, in the investigation of forward proton-proton and antiproton-proton elastic scattering, is exemplified by means of a Pomeron-Reggeon model with totally nondegenerate trajectories.
1703.04958
Shan Cheng
Shan Cheng, Ya-lan Zhang, Jun Hua, Hsiang-nan Li, and Zhen-jun Xiao
Revisiting the factorization theorem for $\rho \gamma^{*} \to \pi(\rho)$ at twist 3
7 pages, 2 figures, Accepted for publication in Physical Review D
Phys. Rev. D 95, 076005 (2017)
10.1103/PhysRevD.95.076005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the proof of the perturbative QCD factorization for the exclusive processes $\rho \gamma^{\star} \to \pi(\rho)$ at the two-parton twist-3 level. It is pointed out that the residual collinear divergences observed in the literature, which break the factorization of the above processes at the considered accuracy, are attributed to the improper insertion of the Fierz identity for factorizing the fermion flow. We show that the factorization theorem indeed holds at the two-parton twist-3 level after the mishandling is corrected.
[ { "created": "Wed, 15 Mar 2017 06:38:58 GMT", "version": "v1" }, { "created": "Thu, 16 Mar 2017 07:35:24 GMT", "version": "v2" }, { "created": "Fri, 31 Mar 2017 12:51:40 GMT", "version": "v3" } ]
2017-04-12
[ [ "Cheng", "Shan", "" ], [ "Zhang", "Ya-lan", "" ], [ "Hua", "Jun", "" ], [ "Li", "Hsiang-nan", "" ], [ "Xiao", "Zhen-jun", "" ] ]
We revisit the proof of the perturbative QCD factorization for the exclusive processes $\rho \gamma^{\star} \to \pi(\rho)$ at the two-parton twist-3 level. It is pointed out that the residual collinear divergences observed in the literature, which break the factorization of the above processes at the considered accuracy, are attributed to the improper insertion of the Fierz identity for factorizing the fermion flow. We show that the factorization theorem indeed holds at the two-parton twist-3 level after the mishandling is corrected.
1407.1725
Pratishruti Saha
Pratishruti Saha, Ken Kiers, David London and Alejandro Szynkman
Detecting New Physics in Rare Top Decays at the LHC
Published version
Phys. Rev. D 90, 094016 (2014)
10.1103/PhysRevD.90.094016
UdeM-GPP-TH-14-234
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the companion paper it was shown that there are six observables in $gg\to t \bar t \to (b \bar b c) (\bar b \ell \bar \nu)$ that can be used to reveal the presence of new physics (NP) in $t \to b \bar b c$. In the present paper we examine the prospects for detecting and identifying such NP at the LHC, in both the short term and long term. To this end, we develop an algorithm for extracting the NP parameters from measurements of the observables. In the short term, depending on what measurements have been made, there are several different ways of detecting the presence of NP. It may even be possible to approximately determine the values of certain NP parameters. In the long term, it is expected that all six observables will be measured. The values of the NP parameters can then be determined reasonably precisely from a fit to these measurements, which will provide good information about the type of NP present in $t \to b \bar b c$.
[ { "created": "Mon, 7 Jul 2014 14:23:43 GMT", "version": "v1" }, { "created": "Thu, 1 Oct 2015 12:41:28 GMT", "version": "v2" } ]
2015-10-02
[ [ "Saha", "Pratishruti", "" ], [ "Kiers", "Ken", "" ], [ "London", "David", "" ], [ "Szynkman", "Alejandro", "" ] ]
In the companion paper it was shown that there are six observables in $gg\to t \bar t \to (b \bar b c) (\bar b \ell \bar \nu)$ that can be used to reveal the presence of new physics (NP) in $t \to b \bar b c$. In the present paper we examine the prospects for detecting and identifying such NP at the LHC, in both the short term and long term. To this end, we develop an algorithm for extracting the NP parameters from measurements of the observables. In the short term, depending on what measurements have been made, there are several different ways of detecting the presence of NP. It may even be possible to approximately determine the values of certain NP parameters. In the long term, it is expected that all six observables will be measured. The values of the NP parameters can then be determined reasonably precisely from a fit to these measurements, which will provide good information about the type of NP present in $t \to b \bar b c$.
hep-ph/0008019
Ed Stoeffhaas
V. Barger, B. Kayser, J. Learned, T. Weiler, and K. Whisnant
Fate of the Sterile Neutrino
11 pages, Latex2.09, no figures
Phys.Lett.B489:345-352,2000
10.1016/S0370-2693(00)00950-3
MADPH-00-1187, VAND-TH-00-7, AMES-HET 00-011
hep-ph
null
In light of recent Super-Kamiokande data and global fits that seem to exclude both pure \nu_\mu \to \nu_s oscillations of atmospheric neutrinos and pure \nu_e \to \nu_s oscillations of solar neutrinos (where \nu_s is a sterile neutrino), we reconsider four-neutrino models to explain the LSND, atmospheric, and solar neutrino oscillation indications. We argue that the solar data, with the exception of the ^{37}Cl results, are suggestive of \nu_e \to \nu_s oscillations that average to a probability of approximately 1/2. In this interpretation, with two pairs of nearly degenerate mass eigenstates separated by order 1 eV, the day-night asymmetry, seasonal dependence, and energy dependence for ^8B neutrinos should be small. Alternatively, we find that four-neutrino models with one mass eigenstate widely separated from the others (and with small sterile mixings to active neutrinos) may now be acceptable in light of recently updated LSND results; the ^{37}Cl data can be accommodated in this model. For each scenario, we present simple four-neutrino mixing matrices that fit the stated criterion and discuss future tests.
[ { "created": "Wed, 2 Aug 2000 16:44:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Barger", "V.", "" ], [ "Kayser", "B.", "" ], [ "Learned", "J.", "" ], [ "Weiler", "T.", "" ], [ "Whisnant", "K.", "" ] ]
In light of recent Super-Kamiokande data and global fits that seem to exclude both pure \nu_\mu \to \nu_s oscillations of atmospheric neutrinos and pure \nu_e \to \nu_s oscillations of solar neutrinos (where \nu_s is a sterile neutrino), we reconsider four-neutrino models to explain the LSND, atmospheric, and solar neutrino oscillation indications. We argue that the solar data, with the exception of the ^{37}Cl results, are suggestive of \nu_e \to \nu_s oscillations that average to a probability of approximately 1/2. In this interpretation, with two pairs of nearly degenerate mass eigenstates separated by order 1 eV, the day-night asymmetry, seasonal dependence, and energy dependence for ^8B neutrinos should be small. Alternatively, we find that four-neutrino models with one mass eigenstate widely separated from the others (and with small sterile mixings to active neutrinos) may now be acceptable in light of recently updated LSND results; the ^{37}Cl data can be accommodated in this model. For each scenario, we present simple four-neutrino mixing matrices that fit the stated criterion and discuss future tests.
1012.0147
Alexander Rudenko S.
I.B. Khriplovich, A.S. Rudenko
$K^+_{l3\gamma}$ decays revisited: branching ratios and T-odd momenta correlations
13 pages, 11 figures; references added
Phys. Atom. Nucl. 74: 1214-1222,2011
10.1134/S1063778811080102
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the branching ratios of the $K^+ \to \pi^0 l^+ \nu_l\gamma (l = e, \mu)$ decays, and the T-odd triple momenta correlations $\xi=\vec{q}\cdot[\vec{p}_l \times \vec{p}_\pi]/M^3_K$, due to the electromagnetic final state interaction, in these processes. The contributions on the order of $\omega^{-1}$ and $\omega^0$ to the corresponding amplitudes are treated exactly. For the branching ratios, the corrections on the order of $\omega$ are estimated and demonstrated to be small. We compare the results with those of other authors. In some cases our results differ considerably from the previous ones.
[ { "created": "Wed, 1 Dec 2010 10:21:12 GMT", "version": "v1" }, { "created": "Fri, 3 Dec 2010 09:59:29 GMT", "version": "v2" } ]
2015-05-20
[ [ "Khriplovich", "I. B.", "" ], [ "Rudenko", "A. S.", "" ] ]
We calculate the branching ratios of the $K^+ \to \pi^0 l^+ \nu_l\gamma (l = e, \mu)$ decays, and the T-odd triple momenta correlations $\xi=\vec{q}\cdot[\vec{p}_l \times \vec{p}_\pi]/M^3_K$, due to the electromagnetic final state interaction, in these processes. The contributions on the order of $\omega^{-1}$ and $\omega^0$ to the corresponding amplitudes are treated exactly. For the branching ratios, the corrections on the order of $\omega$ are estimated and demonstrated to be small. We compare the results with those of other authors. In some cases our results differ considerably from the previous ones.
hep-ph/9608380
Matthias Burkardt
Matthias Burkardt (NMSU)
Confinement in Light-Front QCD
Contributed to PANIC96, LATEX (sprocl), 2 pages, 1 figure
null
null
null
hep-ph
null
Numerical results for the calculation of the (rest-frame) $Q\bar{Q}$ potential, for light-front quantized $QCD_{2+1}$ on a $\perp$ lattice are presented. Both in the longitudinal as well as the $\perp$ spatial directions one obtains linear confinement. The resulting potential is almost rotational symmetric.
[ { "created": "Tue, 20 Aug 1996 17:59:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Burkardt", "Matthias", "", "NMSU" ] ]
Numerical results for the calculation of the (rest-frame) $Q\bar{Q}$ potential, for light-front quantized $QCD_{2+1}$ on a $\perp$ lattice are presented. Both in the longitudinal as well as the $\perp$ spatial directions one obtains linear confinement. The resulting potential is almost rotational symmetric.
1601.05777
Satoshi Shirai
Xiaochuan Lu, Satoshi Shirai and Takahiro Terada
Testing ATLAS Z+MET Excess with LHC Run 2
18 pages, 2 tables, 8 figures. Version accepted for publication in JHEP
JHEP 05 (2016) 108
10.1007/JHEP05(2016)108
DESY 16-005, UT-16-02, APCTP Pre2016-003
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ATLAS collaboration reported a 3sigma excess in the search of events containing on-Z dilepton, jets, and large missing momentum (MET) in the 8 TeV LHC run. Motivated by this excess, many models of new physics have been proposed. Recently, the ATLAS and CMS collaborations reported new results for similar Z+MET channels in the 13 TeV run. In this paper, we comprehensively discuss the consistency between the proposed models and the LHC results of Run 1 and Run 2. We find that in models with heavy gluino production, there is generically some tension between the 8 TeV and 13 TeV results. On the other hand, models with light squark production provide relatively better fitting to both results.
[ { "created": "Thu, 21 Jan 2016 20:45:46 GMT", "version": "v1" }, { "created": "Wed, 11 May 2016 11:57:27 GMT", "version": "v2" } ]
2016-05-23
[ [ "Lu", "Xiaochuan", "" ], [ "Shirai", "Satoshi", "" ], [ "Terada", "Takahiro", "" ] ]
The ATLAS collaboration reported a 3sigma excess in the search of events containing on-Z dilepton, jets, and large missing momentum (MET) in the 8 TeV LHC run. Motivated by this excess, many models of new physics have been proposed. Recently, the ATLAS and CMS collaborations reported new results for similar Z+MET channels in the 13 TeV run. In this paper, we comprehensively discuss the consistency between the proposed models and the LHC results of Run 1 and Run 2. We find that in models with heavy gluino production, there is generically some tension between the 8 TeV and 13 TeV results. On the other hand, models with light squark production provide relatively better fitting to both results.
1908.06061
Bogdan Damski
Bogdan Damski
Electromagnetic angular momentum of the electron: One-loop studies
14 pages, published version
Nucl. Phys. B 949, 114828 (2019)
10.1016/j.nuclphysb.2019.114828
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study angular momentum of the electron stored in its electric and magnetic fields. We use for this purpose quantum electrodynamics in the covariant gauge. We show that a finite one-loop result for such angular momentum can be obtained without invoking any renormalization procedure. We compare it to the classical estimation relying on a short-distance cutoff.
[ { "created": "Fri, 16 Aug 2019 17:17:25 GMT", "version": "v1" }, { "created": "Wed, 20 Nov 2019 15:07:25 GMT", "version": "v2" } ]
2019-11-21
[ [ "Damski", "Bogdan", "" ] ]
We study angular momentum of the electron stored in its electric and magnetic fields. We use for this purpose quantum electrodynamics in the covariant gauge. We show that a finite one-loop result for such angular momentum can be obtained without invoking any renormalization procedure. We compare it to the classical estimation relying on a short-distance cutoff.
hep-ph/0501082
Cheng Jian-Feng
Jian-Feng Cheng, Dong-Sheng Du and Cai-Dian Lu
Prediction of $B_c\to D\pi$ in the pQCD approach
The numerical results have been updated and some errors have been corrected. (10 pages, 16 figures, revtex4)
Eur.Phys.J.C45:711-720,2006
10.1140/epjc/s2005-02453-0
null
hep-ph hep-ex
null
We investigate the branching ratios and direct CP asymmetries of $B_c^+\to D^0\pi^+$ and $B_c^+\to D^+\pi^0$ decays in the PQCD approach. All the diagrams with emission topology or annihilation topology are calculated strictly. A branching ratio of $10^{-6}$ and $10^{-7}$ for $B_c^+\to D^0\pi^+$ and $B_c^+\to D^+\pi^0$ decay is predicted, respectively. Because of the different weak phase and strong phase from penguin operator and two kinds of tree operator contributions, we predict a possible large direct CP violation: $A^{\rm dir}_{cp} (B_c^\pm \to D^0 \pi^\pm)\approx -50%$ and $A^{\rm dir}_{cp} (B_c^\pm \to D^\pm \pi^0)\approx 25%$ when $\gamma=55^\circ$, which can be tested in the coming LHC.
[ { "created": "Tue, 11 Jan 2005 02:23:55 GMT", "version": "v1" }, { "created": "Thu, 22 Sep 2005 09:49:55 GMT", "version": "v2" } ]
2009-01-07
[ [ "Cheng", "Jian-Feng", "" ], [ "Du", "Dong-Sheng", "" ], [ "Lu", "Cai-Dian", "" ] ]
We investigate the branching ratios and direct CP asymmetries of $B_c^+\to D^0\pi^+$ and $B_c^+\to D^+\pi^0$ decays in the PQCD approach. All the diagrams with emission topology or annihilation topology are calculated strictly. A branching ratio of $10^{-6}$ and $10^{-7}$ for $B_c^+\to D^0\pi^+$ and $B_c^+\to D^+\pi^0$ decay is predicted, respectively. Because of the different weak phase and strong phase from penguin operator and two kinds of tree operator contributions, we predict a possible large direct CP violation: $A^{\rm dir}_{cp} (B_c^\pm \to D^0 \pi^\pm)\approx -50%$ and $A^{\rm dir}_{cp} (B_c^\pm \to D^\pm \pi^0)\approx 25%$ when $\gamma=55^\circ$, which can be tested in the coming LHC.
2112.03755
Nicola Rossi Dr.
Aldo Ianni, Massimo Mannarelli and Nicola Rossi
A new approach to dark matter from the mass-radius diagram of the Universe
20 pages, 5 figures
null
null
null
hep-ph astro-ph.GA hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern cosmology successfully deals with the origin and the evolution of the Universe at large scales, but it is unable to completely answer the question about the nature of the fundamental objects that it is describing. As a matter of fact, about 95\% of the constituents of the Universe is indeed completely unknown: it cannot be described in terms of known particles. Despite intense efforts to shed light on this literal darkness by dark matter and dark energy direct and indirect searches, not much progress has been made so far. In this work, we take a different perspective by reviewing and elaborating an old idea of studying the mass-radius distribution of structures in the Universe in relationship with the fundamental forces acting on them. As we will describe in detail, the distribution of the observed structures in the Universe is not completely random, but it reflects the intimate features of the involved particles and the nature of the fundamental interactions at play. The observed structures cluster in restricted regions of the mass-radius diagram linked to known particles, with the remarkable exception of very large structures that seem to be linked to an unknown particle in the sub-eV mass range. We conjecture that this new particle is a self-interacting dark matter candidate.
[ { "created": "Tue, 7 Dec 2021 15:10:59 GMT", "version": "v1" } ]
2021-12-08
[ [ "Ianni", "Aldo", "" ], [ "Mannarelli", "Massimo", "" ], [ "Rossi", "Nicola", "" ] ]
Modern cosmology successfully deals with the origin and the evolution of the Universe at large scales, but it is unable to completely answer the question about the nature of the fundamental objects that it is describing. As a matter of fact, about 95\% of the constituents of the Universe is indeed completely unknown: it cannot be described in terms of known particles. Despite intense efforts to shed light on this literal darkness by dark matter and dark energy direct and indirect searches, not much progress has been made so far. In this work, we take a different perspective by reviewing and elaborating an old idea of studying the mass-radius distribution of structures in the Universe in relationship with the fundamental forces acting on them. As we will describe in detail, the distribution of the observed structures in the Universe is not completely random, but it reflects the intimate features of the involved particles and the nature of the fundamental interactions at play. The observed structures cluster in restricted regions of the mass-radius diagram linked to known particles, with the remarkable exception of very large structures that seem to be linked to an unknown particle in the sub-eV mass range. We conjecture that this new particle is a self-interacting dark matter candidate.
1101.4456
Lei Wu
Junjie Cao, Lin Wang, Lei Wu, Jin Min Yang
Top quark forward-backward asymmetry, FCNC decays and like-sign pair production as a joint probe of new physics
discussions added, revised version accepted by PRD
null
10.1103/PhysRevD.84.074001
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The anomaly of the top quark forward-backward asymmetry $A^t_{FB}$ observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z') which has sizable flavor changing coupling for top and up quarks. This gauge boson can also induce the top quark flavor-changing neutral-current (FCNC) decays and the like-sign top pair production at the LHC. In this work we focus on two models which predict such a Z', namely the left-right model and the U(1)_X model, to investigate the correlated effects on $A^t_{FB}$, the FCNC decays $t -> u V$ ($V=g,Z,\gamma$) and the like-sign top pair production at the LHC. We also pay special attention to the most recently measured $A^t_{FB}$ in the large top pair invariant mass region. We find that under the current experimental constraints both models can alleviate the deviation of $A^t_{FB}$ and, meanwhile, enhance the like-sign top pair production to the detectable level of the LHC. We also find that the two models give different predictions for the observables and their correlations, and thus they may even be distinguished by jointly studying these top quark observables.
[ { "created": "Mon, 24 Jan 2011 07:22:53 GMT", "version": "v1" }, { "created": "Sun, 20 Feb 2011 04:21:06 GMT", "version": "v2" }, { "created": "Fri, 16 Sep 2011 01:27:21 GMT", "version": "v3" } ]
2013-05-29
[ [ "Cao", "Junjie", "" ], [ "Wang", "Lin", "" ], [ "Wu", "Lei", "" ], [ "Yang", "Jin Min", "" ] ]
The anomaly of the top quark forward-backward asymmetry $A^t_{FB}$ observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z') which has sizable flavor changing coupling for top and up quarks. This gauge boson can also induce the top quark flavor-changing neutral-current (FCNC) decays and the like-sign top pair production at the LHC. In this work we focus on two models which predict such a Z', namely the left-right model and the U(1)_X model, to investigate the correlated effects on $A^t_{FB}$, the FCNC decays $t -> u V$ ($V=g,Z,\gamma$) and the like-sign top pair production at the LHC. We also pay special attention to the most recently measured $A^t_{FB}$ in the large top pair invariant mass region. We find that under the current experimental constraints both models can alleviate the deviation of $A^t_{FB}$ and, meanwhile, enhance the like-sign top pair production to the detectable level of the LHC. We also find that the two models give different predictions for the observables and their correlations, and thus they may even be distinguished by jointly studying these top quark observables.
2110.15211
Frank Siegert
Katharina Danziger, Stefan H\"oche, Frank Siegert
Reducing negative weights in Monte Carlo event generation with Sherpa
20 pages, 8 figures
null
null
MCNET-21-30, FERMILAB-PUB-21-536-T
hep-ph hep-ex
http://creativecommons.org/licenses/by-sa/4.0/
An increase in theoretical precision of Monte Carlo event generators is typically accompanied by an increased need for computational resources. One major obstacle are negative weighted events, which appear in Monte Carlo simulations with higher perturbative accuracy. While they can be handled somewhat easily in fixed-order calculations, they are a major concern for particle level event simulations. In this article, the origin of negative weights in the S-MC@NLO method is reviewed and mechanisms to reduce the negative weight fraction in simulations with the Sherpa event generator are presented, with a focus on V+jets and tt+jets simulations.
[ { "created": "Thu, 28 Oct 2021 15:29:33 GMT", "version": "v1" } ]
2021-10-29
[ [ "Danziger", "Katharina", "" ], [ "Höche", "Stefan", "" ], [ "Siegert", "Frank", "" ] ]
An increase in theoretical precision of Monte Carlo event generators is typically accompanied by an increased need for computational resources. One major obstacle are negative weighted events, which appear in Monte Carlo simulations with higher perturbative accuracy. While they can be handled somewhat easily in fixed-order calculations, they are a major concern for particle level event simulations. In this article, the origin of negative weights in the S-MC@NLO method is reviewed and mechanisms to reduce the negative weight fraction in simulations with the Sherpa event generator are presented, with a focus on V+jets and tt+jets simulations.
hep-ph/0304069
Eung Jin Chun
Eung Jin Chun, Kang Young Lee and Seong Chan Park
Testing Higgs Triplet Model and Neutrino Mass Patterns
13 pages, revtex
Phys.Lett. B566 (2003) 142-151
10.1016/S0370-2693(03)00770-6
KIAS-P03023
hep-ph
null
The observed neutrino oscillation data might be explained by new physics at a TeV scale, which is testable in the future experiments. Among various possibilities, the low-energy Higgs triplet model is a prime candidate of such new physics since it predicts clean signatures of lepton flavor violating processes directly related to the neutrino masses and mixing. It is discussed how various neutrino mass patterns can be discriminated by examining the lepton flavor violating decays of charged leptons as well as the collider signatures of a doubly charged Higgs boson in the model.
[ { "created": "Mon, 7 Apr 2003 12:17:21 GMT", "version": "v1" } ]
2010-04-05
[ [ "Chun", "Eung Jin", "" ], [ "Lee", "Kang Young", "" ], [ "Park", "Seong Chan", "" ] ]
The observed neutrino oscillation data might be explained by new physics at a TeV scale, which is testable in the future experiments. Among various possibilities, the low-energy Higgs triplet model is a prime candidate of such new physics since it predicts clean signatures of lepton flavor violating processes directly related to the neutrino masses and mixing. It is discussed how various neutrino mass patterns can be discriminated by examining the lepton flavor violating decays of charged leptons as well as the collider signatures of a doubly charged Higgs boson in the model.
hep-ph/0308195
David Rainwater
John Campbell (Argonne), R.K. Ellis (FNAL), D. Rainwater (DESY)
Next-to-leading order QCD predictions for W+2j and Z+2j production at the CERN LHC
24p, PRD version, ref's corrected, add. paragraph to explain pTmiss fig
Phys.Rev.D68:094021,2003
10.1103/PhysRevD.68.094021
ANL-HEP-PR-03-063, FERMILAB-Pub-03/234-T, DESY-03-036
hep-ph
null
We present cross sections and differential distributions for QCD radiative corrections to the QCD processes pp -> W+2j and pp -> Z+2j at the CERN LHC. Calculations are performed with the Monte Carlo program MCFM. Cross section dependence on the renormalization and factorization scales is greatly reduced, except for the heavy-flavor case of Wbb~, which has new features at next-to-leading order at the LHC. We also present cross sections for Wbb~ and Z+2j in kinematic configurations relevant for Higgs boson searches.
[ { "created": "Tue, 19 Aug 2003 13:59:31 GMT", "version": "v1" }, { "created": "Thu, 13 Nov 2003 15:43:07 GMT", "version": "v2" } ]
2008-11-26
[ [ "Campbell", "John", "", "Argonne" ], [ "Ellis", "R. K.", "", "FNAL" ], [ "Rainwater", "D.", "", "DESY" ] ]
We present cross sections and differential distributions for QCD radiative corrections to the QCD processes pp -> W+2j and pp -> Z+2j at the CERN LHC. Calculations are performed with the Monte Carlo program MCFM. Cross section dependence on the renormalization and factorization scales is greatly reduced, except for the heavy-flavor case of Wbb~, which has new features at next-to-leading order at the LHC. We also present cross sections for Wbb~ and Z+2j in kinematic configurations relevant for Higgs boson searches.
0808.0196
Spencer Chang
Spencer Chang, Aaron Pierce, and Neal Weiner
Using the Energy Spectrum at DAMA/LIBRA to Probe Light Dark Matter
5 pages, 5 figures
Phys.Rev.D79:115011,2009
10.1103/PhysRevD.79.115011
MCTP-08-5
hep-ph astro-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A weakly interacting massive particle (WIMP) weighing only a few GeV has been invoked as an explanation for the signal from the DAMA/LIBRA experiment. We show that the data from DAMA/LIBRA are now powerful enough to strongly constrain the properties of any putative WIMP. Accounting for the detailed recoil spectrum, a light WIMP with a Maxwellian velocity distribution and a spin-independent (SI) interaction cannot account for the data. Even neglecting the spectrum, much of the parameter space is excluded by limits from the DAMA unmodulated signal at low energies. Significant modifications to the astrophysics or particle physics can open light mass windows.
[ { "created": "Fri, 1 Aug 2008 22:39:24 GMT", "version": "v1" } ]
2009-06-30
[ [ "Chang", "Spencer", "" ], [ "Pierce", "Aaron", "" ], [ "Weiner", "Neal", "" ] ]
A weakly interacting massive particle (WIMP) weighing only a few GeV has been invoked as an explanation for the signal from the DAMA/LIBRA experiment. We show that the data from DAMA/LIBRA are now powerful enough to strongly constrain the properties of any putative WIMP. Accounting for the detailed recoil spectrum, a light WIMP with a Maxwellian velocity distribution and a spin-independent (SI) interaction cannot account for the data. Even neglecting the spectrum, much of the parameter space is excluded by limits from the DAMA unmodulated signal at low energies. Significant modifications to the astrophysics or particle physics can open light mass windows.
1610.09090
Newton Nath
Newton Nath, Monojit Ghosh, Srubabati Goswami, Shivani Gupta
Phenomenological study of extended seesaw model for light sterile neutrino
29 pages, 6 figures and 7 tables, Version accepted for publication in JHEP
null
10.1007/JHEP03(2017)075
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the zero textures of the Yukawa matrices in the minimal extended type-I seesaw (MES) model which can give rise to $\sim$ eV scale sterile neutrinos. In this model, three right handed neutrinos and one extra singlet $S$ are added to generate a light sterile neutrino. The light neutrino mass matrix for the active neutrinos, $ m_{\nu}$, depends on the Dirac neutrino mass matrix ($ M_{D} $), Majorana neutrino mass matrix ($ M_{R} $) and the mass matrix ($ M_{S} $) coupling the right handed neutrinos and the singlet. The model predicts one of the light neutrino masses to vanish. We systematically investigate the zero textures in $ M_{D} $ and observe that maximum five zeros in $ M_{D} $ can lead to viable zero textures in $ m_{\nu} $. For this study we consider four different forms for $ M_R $ (one diagonal and three off diagonal) and two different forms of $(M_{S})$ containing one zero. Remarkably we obtain only two allowed forms of $ m_{\nu} $ ($m_{e\tau} = 0 $ and $m_{\tau\tau}=0$) having inverted hierarchical mass spectrum. We re-analyze the phenomenological implications of these two allowed textures of $m_\nu$ in the light of recent neutrino oscillation data. In the context of the MES model, we also express the low energy mass matrix, the mass of the sterile neutrino and the active-sterile mixing in terms of the parameters of the allowed Yukawa matrices. The MES model leads to some extra correlations which disallow some of the Yukawa textures obtained earlier, even though they give allowed one-zero forms of $m_\nu$. We show that the allowed textures in our study can be realized in a simple way in a model based on MES mechanism with a discrete Abelian flavor symmetry group $Z_8 \times Z_2$.
[ { "created": "Fri, 28 Oct 2016 06:32:15 GMT", "version": "v1" }, { "created": "Tue, 7 Mar 2017 13:21:34 GMT", "version": "v2" } ]
2017-04-05
[ [ "Nath", "Newton", "" ], [ "Ghosh", "Monojit", "" ], [ "Goswami", "Srubabati", "" ], [ "Gupta", "Shivani", "" ] ]
We study the zero textures of the Yukawa matrices in the minimal extended type-I seesaw (MES) model which can give rise to $\sim$ eV scale sterile neutrinos. In this model, three right handed neutrinos and one extra singlet $S$ are added to generate a light sterile neutrino. The light neutrino mass matrix for the active neutrinos, $ m_{\nu}$, depends on the Dirac neutrino mass matrix ($ M_{D} $), Majorana neutrino mass matrix ($ M_{R} $) and the mass matrix ($ M_{S} $) coupling the right handed neutrinos and the singlet. The model predicts one of the light neutrino masses to vanish. We systematically investigate the zero textures in $ M_{D} $ and observe that maximum five zeros in $ M_{D} $ can lead to viable zero textures in $ m_{\nu} $. For this study we consider four different forms for $ M_R $ (one diagonal and three off diagonal) and two different forms of $(M_{S})$ containing one zero. Remarkably we obtain only two allowed forms of $ m_{\nu} $ ($m_{e\tau} = 0 $ and $m_{\tau\tau}=0$) having inverted hierarchical mass spectrum. We re-analyze the phenomenological implications of these two allowed textures of $m_\nu$ in the light of recent neutrino oscillation data. In the context of the MES model, we also express the low energy mass matrix, the mass of the sterile neutrino and the active-sterile mixing in terms of the parameters of the allowed Yukawa matrices. The MES model leads to some extra correlations which disallow some of the Yukawa textures obtained earlier, even though they give allowed one-zero forms of $m_\nu$. We show that the allowed textures in our study can be realized in a simple way in a model based on MES mechanism with a discrete Abelian flavor symmetry group $Z_8 \times Z_2$.
2204.12152
Rafiqul Rahaman
Rafiqul Rahaman
On two-body and three-body spin correlations in leptonic $t\bar{t}Z$ production and anomalous couplings at the LHC
31 pages, 12 figures and 4 tables
null
10.1007/JHEP02(2023)077
HRI-RECAPP-2022-006
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We study the anomalous $t\bar{t}Z$ couplings in the $t\bar{t}Z$ production in leptonic final state at the $13$ TeV LHC. We use the polarizations of top quarks and $Z$ boson, two-body and three-body spin correlations among the top quarks and $Z$ boson, and the cross section to probe the anomalous couplings. We estimate one parameter and simultaneous limits on the couplings of the effective vertex as well as the effective operators for a set of luminosities $150$ fb$^{-1}$, $300$ fb$^{-1}$, $1000$ fb$^{-1}$, and $3000$ fb$^{-1}$. The polarizations and the spin correlations are found to be helpful on top of the cross section to better constrain the anomalous couplings.
[ { "created": "Tue, 26 Apr 2022 08:41:17 GMT", "version": "v1" }, { "created": "Tue, 21 Mar 2023 09:39:31 GMT", "version": "v2" } ]
2023-03-22
[ [ "Rahaman", "Rafiqul", "" ] ]
We study the anomalous $t\bar{t}Z$ couplings in the $t\bar{t}Z$ production in leptonic final state at the $13$ TeV LHC. We use the polarizations of top quarks and $Z$ boson, two-body and three-body spin correlations among the top quarks and $Z$ boson, and the cross section to probe the anomalous couplings. We estimate one parameter and simultaneous limits on the couplings of the effective vertex as well as the effective operators for a set of luminosities $150$ fb$^{-1}$, $300$ fb$^{-1}$, $1000$ fb$^{-1}$, and $3000$ fb$^{-1}$. The polarizations and the spin correlations are found to be helpful on top of the cross section to better constrain the anomalous couplings.
1805.03862
Michal Praszalowicz
Michal Praszalowicz
Exotic interpretation of $\Omega_c$ excited states
Talk at the Moriond QCD 2018, 4 pages, 4 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We use the chiral quark-soliton model to interpret five excited $\Omega_c$ states recently reported by the LHCb collaboration and confirmed by Belle. We briefly recapitulate the model and its application to light baryons. We then show how the model can be extended to the case of baryons with one heavy quark. We test the model against ground state heavy baryons and then examine possible excitations. We argue that it is not possible to accommodate all five $\Omega_c$'s within five parity minus excitations predicetd by the model and propose to interpret two narrowest states split by 70 MeV as pentaquarks belonging to the SU(3) representation $\overline{15}$.
[ { "created": "Thu, 10 May 2018 07:32:55 GMT", "version": "v1" } ]
2018-05-11
[ [ "Praszalowicz", "Michal", "" ] ]
We use the chiral quark-soliton model to interpret five excited $\Omega_c$ states recently reported by the LHCb collaboration and confirmed by Belle. We briefly recapitulate the model and its application to light baryons. We then show how the model can be extended to the case of baryons with one heavy quark. We test the model against ground state heavy baryons and then examine possible excitations. We argue that it is not possible to accommodate all five $\Omega_c$'s within five parity minus excitations predicetd by the model and propose to interpret two narrowest states split by 70 MeV as pentaquarks belonging to the SU(3) representation $\overline{15}$.
1301.0933
Andrew Larkoski
Andrew J. Larkoski, Juan J. Lopez-Villarejo, Peter Skands
Helicity-Dependent Showers and Matching with VINCIA
Switched sections 2 and 3 for clarity
null
10.1103/PhysRevD.87.054033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an antenna-shower formalism that includes helicity dependence for massless partons. The formalism applies to both traditional (global) showers and to sector-based variants. We combine the shower with VINCIA's multiplicative approach to matrix-element matching, generalized to operate on each helicity configuration separately. The result is a substantial gain in computational speed for high parton multiplicities. We present an implementation of both sector and global showers, with min and max variations, and helicity-dependent tree-level matching applied for vector bosons or Higgs decay to q qbar plus up to 4 gluons and for Higgs decay to up to 5 gluons.
[ { "created": "Sat, 5 Jan 2013 19:31:31 GMT", "version": "v1" }, { "created": "Wed, 6 Mar 2013 15:43:49 GMT", "version": "v2" } ]
2013-04-03
[ [ "Larkoski", "Andrew J.", "" ], [ "Lopez-Villarejo", "Juan J.", "" ], [ "Skands", "Peter", "" ] ]
We present an antenna-shower formalism that includes helicity dependence for massless partons. The formalism applies to both traditional (global) showers and to sector-based variants. We combine the shower with VINCIA's multiplicative approach to matrix-element matching, generalized to operate on each helicity configuration separately. The result is a substantial gain in computational speed for high parton multiplicities. We present an implementation of both sector and global showers, with min and max variations, and helicity-dependent tree-level matching applied for vector bosons or Higgs decay to q qbar plus up to 4 gluons and for Higgs decay to up to 5 gluons.
2109.00216
Zhi-Peng Xing
Zhi-Peng Xing and Zhen-Xing Zhao
QCD sum rules analysis of weak decays of doubly heavy baryons: the $b\to c$ processes
13 pages, 5 figures
null
10.1140/epjc/s10052-021-09902-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A comprehensive study of $b\to c$ weak decays of doubly heavy baryons is presented in this paper. The transition form factors as well as the pole residues of the initial and final states are respectively obtained by investigating the three-point and two-point correlation functions in QCD sum rules. Contributions from up to dimension-6 operators are respectively considered for the two-point and three-point correlation functions. The obtained form factors are then applied to a phenomenological analysis of semi-leptonic decays.
[ { "created": "Wed, 1 Sep 2021 07:27:40 GMT", "version": "v1" }, { "created": "Mon, 6 Sep 2021 03:06:06 GMT", "version": "v2" }, { "created": "Mon, 20 Sep 2021 05:29:51 GMT", "version": "v3" }, { "created": "Fri, 19 Nov 2021 07:55:37 GMT", "version": "v4" } ]
2022-01-05
[ [ "Xing", "Zhi-Peng", "" ], [ "Zhao", "Zhen-Xing", "" ] ]
A comprehensive study of $b\to c$ weak decays of doubly heavy baryons is presented in this paper. The transition form factors as well as the pole residues of the initial and final states are respectively obtained by investigating the three-point and two-point correlation functions in QCD sum rules. Contributions from up to dimension-6 operators are respectively considered for the two-point and three-point correlation functions. The obtained form factors are then applied to a phenomenological analysis of semi-leptonic decays.
hep-ph/9702408
Bernd Kniehl
J. Binnewies (Hamburg), B.A. Kniehl (MPI Munich), G. Kramer (Hamburg)
Coherent Description of D^{*+-} Production in e^+e^- and Low-Q^2 ep Collisions
31 pages (Latex), 11 figures (Postscript). This version of the manuscript is identical with the journal publication
Z.Phys. C76 (1997) 677-688
null
DESY 97-012 and MPI/PhT/97-009
hep-ph
null
We present new sets of fragmentation functions for D^{*+-} mesons, both at leading and next-to-leading order. They are determined by fitting LEP1 data on inclusive D^{*+-} production in e^+e^- annihilation. In one of the sets, we take the charm-quark fragmentation function to be of the form proposed by Peterson et al. and thus obtain updated values of the epsilon_c parameter and the c -> D^{*+} branching ratio. The new fragmentation functions lead to an excellent description of other e^+e^- data with centre-of-mass energies between 10 and 35 GeV. They also nicely agree with recent HERA data on inclusive D^{*+-} photoproduction in ep collisions, which may be considered as a test of the universality of the fragmentation into D^{*+-} mesons.
[ { "created": "Mon, 24 Feb 1997 19:04:42 GMT", "version": "v1" }, { "created": "Fri, 5 Dec 1997 18:09:16 GMT", "version": "v2" } ]
2008-02-03
[ [ "Binnewies", "J.", "", "Hamburg" ], [ "Kniehl", "B. A.", "", "MPI Munich" ], [ "Kramer", "G.", "", "Hamburg" ] ]
We present new sets of fragmentation functions for D^{*+-} mesons, both at leading and next-to-leading order. They are determined by fitting LEP1 data on inclusive D^{*+-} production in e^+e^- annihilation. In one of the sets, we take the charm-quark fragmentation function to be of the form proposed by Peterson et al. and thus obtain updated values of the epsilon_c parameter and the c -> D^{*+} branching ratio. The new fragmentation functions lead to an excellent description of other e^+e^- data with centre-of-mass energies between 10 and 35 GeV. They also nicely agree with recent HERA data on inclusive D^{*+-} photoproduction in ep collisions, which may be considered as a test of the universality of the fragmentation into D^{*+-} mesons.
hep-ph/9305342
null
H. Baer, F. Paige, S. Protopopescu and X. Tata
Simulating Supersymmetry with ISAJET 7.0/ ISASUSY 1.0
17 pages, FSU-HEP-930329 UH-511-764-93
null
null
null
hep-ph
null
We review the physics assumptions and input used in ISAJET~7.0 / ISA\-SUSY~1.0 that are relevant for simulating fundamental processes within the framework of the Minimal Supersymmetric Standard Model (MSSM) at $p\bar p$ and $pp$ colliders. After a brief discussion of the underlying MSSM framework, we discuss event simulation and list the sparticle production processes and decay modes that have been incorporated into our calculations. We then describe how to set up and run an ISAJET / ISASUSY job and the user input and output formats. The ISAJET program is sufficiently flexible that some non-minimal supersymmetry scenarios may be simulated as well. Finally, plans for future upgrades which include the extension to $e^+ e^-$ collisions, are listed.
[ { "created": "Fri, 28 May 1993 01:36:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baer", "H.", "" ], [ "Paige", "F.", "" ], [ "Protopopescu", "S.", "" ], [ "Tata", "X.", "" ] ]
We review the physics assumptions and input used in ISAJET~7.0 / ISA\-SUSY~1.0 that are relevant for simulating fundamental processes within the framework of the Minimal Supersymmetric Standard Model (MSSM) at $p\bar p$ and $pp$ colliders. After a brief discussion of the underlying MSSM framework, we discuss event simulation and list the sparticle production processes and decay modes that have been incorporated into our calculations. We then describe how to set up and run an ISAJET / ISASUSY job and the user input and output formats. The ISAJET program is sufficiently flexible that some non-minimal supersymmetry scenarios may be simulated as well. Finally, plans for future upgrades which include the extension to $e^+ e^-$ collisions, are listed.
hep-ph/0102025
Johannes Bluemlein
J. Bl\"umlein, V. Ravindran, J. Ruan, and W. Zhu
Twist-4 Gluon Recombination Corrections for Deep Inelastic Structure Functions
10 pages LATEX, 2 style file, 3 eps-files
Phys.Lett. B504 (2001) 235-240
10.1016/S0370-2693(01)00305-7
DESY 01-007
hep-ph hep-ex
null
We calculate twist--4 coefficient functions for the deep inelastic structure function $F_2(x,Q^2)$ associated to 4--gluon operator matrix elements for general values of the Bjorken variable $x$ and study the numerical effect on the slope $\partial F_2(x,Q^2)/\partial \log Q^2$. It is shown that these contributions diminish the strongly rising twist--2 terms towards small values of $x$.
[ { "created": "Fri, 2 Feb 2001 18:41:34 GMT", "version": "v1" }, { "created": "Sun, 4 Feb 2001 11:16:43 GMT", "version": "v2" } ]
2009-11-07
[ [ "Blümlein", "J.", "" ], [ "Ravindran", "V.", "" ], [ "Ruan", "J.", "" ], [ "Zhu", "W.", "" ] ]
We calculate twist--4 coefficient functions for the deep inelastic structure function $F_2(x,Q^2)$ associated to 4--gluon operator matrix elements for general values of the Bjorken variable $x$ and study the numerical effect on the slope $\partial F_2(x,Q^2)/\partial \log Q^2$. It is shown that these contributions diminish the strongly rising twist--2 terms towards small values of $x$.
hep-ph/9910491
Misha Stephanov
D.T. Son, M.A. Stephanov
Inverse meson mass ordering in color-flavor-locking phase of high density QCD
18 pages, 3 figures
Phys.Rev. D61 (2000) 074012
10.1103/PhysRevD.61.074012
null
hep-ph nucl-th
null
We derive the effective Lagrangian for the low-energy massive meson excitations of the color-flavor-locking (CFL) phase of QCD with 3 flavors of light quarks. We compute the decay constants, the maximum velocities, and the masses of the mesons at large baryon chemical potential mu. The decay constants are linear in mu. The meson maximum velocities are close to that of sound. The meson masses in the CFL phase are significantly smaller than in the normal QCD vacuum and depend only on bare quark masses. The order of the meson masses is, to some extent, reversed compared to that in the QCD vacuum. In particular, the lightest particle is eta'.
[ { "created": "Tue, 26 Oct 1999 15:28:36 GMT", "version": "v1" }, { "created": "Mon, 6 Dec 1999 02:59:25 GMT", "version": "v2" } ]
2007-05-23
[ [ "Son", "D. T.", "" ], [ "Stephanov", "M. A.", "" ] ]
We derive the effective Lagrangian for the low-energy massive meson excitations of the color-flavor-locking (CFL) phase of QCD with 3 flavors of light quarks. We compute the decay constants, the maximum velocities, and the masses of the mesons at large baryon chemical potential mu. The decay constants are linear in mu. The meson maximum velocities are close to that of sound. The meson masses in the CFL phase are significantly smaller than in the normal QCD vacuum and depend only on bare quark masses. The order of the meson masses is, to some extent, reversed compared to that in the QCD vacuum. In particular, the lightest particle is eta'.
hep-ph/9904362
Martynenko Alexei Petrovich
R.N. Faustov, A.P. Martynenko
Proton polarizability and the Lamb shift in muonic hydrogen
8 pages, LaTeX2.09, 2 figures, uses linedraw.sty
Phys.Atom.Nucl. 63 (2000) 845-849; Yad.Fiz. 63 (2000) 915-919
10.1134/1.855715
SSU-HEP-99/04
hep-ph
null
The proton structure and proton polarizability corrections to the Lamb shift of electronic hydrogen and muonic hydrogen were evaluated on the basis of modern experimental data on deep inelastic structure functions. Numerical value of proton polarizability contribution to (2P-2S) Lamb shift is equal to 4.4 GHz.
[ { "created": "Fri, 16 Apr 1999 14:54:17 GMT", "version": "v1" }, { "created": "Mon, 19 Apr 1999 12:46:45 GMT", "version": "v2" } ]
2009-10-31
[ [ "Faustov", "R. N.", "" ], [ "Martynenko", "A. P.", "" ] ]
The proton structure and proton polarizability corrections to the Lamb shift of electronic hydrogen and muonic hydrogen were evaluated on the basis of modern experimental data on deep inelastic structure functions. Numerical value of proton polarizability contribution to (2P-2S) Lamb shift is equal to 4.4 GHz.
hep-ph/9406343
Mark Trodden
M. Trodden (Brown University)
Cosmic Strings and Electroweak Symmetry Restoration in the Two-Higgs Doublet Model
12 pages, 4 figures (available from the author), uses phyzzx, BROWN-HET-945
Mod.Phys.Lett. A9 (1994) 2649-2659
10.1142/S0217732394002495
null
hep-ph
null
We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their CP violating relative phase, does not qualitatively affect the results of Perkins and Davis[1] obtained for the standard electroweak theory. This result is neccessary to ensure the validity of some recently proposed string-mediated electroweak baryogenesis scenarios.
[ { "created": "Mon, 20 Jun 1994 17:32:59 GMT", "version": "v1" } ]
2015-06-25
[ [ "Trodden", "M.", "", "Brown University" ] ]
We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their CP violating relative phase, does not qualitatively affect the results of Perkins and Davis[1] obtained for the standard electroweak theory. This result is neccessary to ensure the validity of some recently proposed string-mediated electroweak baryogenesis scenarios.
1306.3242
Giacomo Cacciapaglia
Giacomo Cacciapaglia (IPN Lyon) and Mairi Sakellariadou (King's Coll. London)
Is F-term hybrid inflation natural within minimal supersymmetric SO(10)?
16 pages
Eur.Phys.J. C74 (2014) 2779
10.1140/epjc/s10052-014-2779-5
KCL-PH-TH/2013-17, LYCEN 2013-05
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine whether F-term supersymmetric hybrid inflation can be embedded within the minimal SO(10) model, in a natural way. We show that none of the singlets of the Standard Model symmetries in the minimal set of SO(10) representations can satisfy the conditions which are necessary for a scalar field to play the role of the inflaton. As a consequence, one has to introduce an extra scalar field, which however may spoil the naturalness of inflation within the context of SO(10). Nevertheless, if we add an extra scalar field, we are then able to construct a model that can accommodate flat directions while it preserves the stability of the inflationary valley.
[ { "created": "Thu, 13 Jun 2013 20:07:42 GMT", "version": "v1" } ]
2015-06-16
[ [ "Cacciapaglia", "Giacomo", "", "IPN Lyon" ], [ "Sakellariadou", "Mairi", "", "King's Coll.\n London" ] ]
We examine whether F-term supersymmetric hybrid inflation can be embedded within the minimal SO(10) model, in a natural way. We show that none of the singlets of the Standard Model symmetries in the minimal set of SO(10) representations can satisfy the conditions which are necessary for a scalar field to play the role of the inflaton. As a consequence, one has to introduce an extra scalar field, which however may spoil the naturalness of inflation within the context of SO(10). Nevertheless, if we add an extra scalar field, we are then able to construct a model that can accommodate flat directions while it preserves the stability of the inflationary valley.
hep-ph/9703375
Marco Fabbrichesi
Nicola Di Bartolomeo and Marco Fabbrichesi
Four-Fermion Effective Interactions and Recent Data at HERA
LaTeX2e (it requires JHEP.cls) 6 EPS figures, final version to be published in Physics Letters B
Phys.Lett. B406 (1997) 237-242
10.1016/S0370-2693(97)00678-3
SISSA 34/97/EP
hep-ph
null
We discuss the possibility of explaining the excess in the cross section at high-Q^2 recently found at HERA in terms of four-fermion effective interactions. To avoid the constraints from low-energy data, we select three special cases in which the contact interaction is a product of vector-vector, axial-axial and vector-axial currents. For these a satisfactory fit of HERA data is possible, while keeping agreement with LEPII and CDF data, for an interaction scale $\Lambda =3.5$ TeV. As the statistics of the experiments improves-and if the effect persists-it will be soon possible to discriminate between such contact terms and the alternative explanation in terms of leptoquark exchange.
[ { "created": "Thu, 20 Mar 1997 16:48:17 GMT", "version": "v1" }, { "created": "Tue, 13 May 1997 08:18:46 GMT", "version": "v2" } ]
2009-10-30
[ [ "Di Bartolomeo", "Nicola", "" ], [ "Fabbrichesi", "Marco", "" ] ]
We discuss the possibility of explaining the excess in the cross section at high-Q^2 recently found at HERA in terms of four-fermion effective interactions. To avoid the constraints from low-energy data, we select three special cases in which the contact interaction is a product of vector-vector, axial-axial and vector-axial currents. For these a satisfactory fit of HERA data is possible, while keeping agreement with LEPII and CDF data, for an interaction scale $\Lambda =3.5$ TeV. As the statistics of the experiments improves-and if the effect persists-it will be soon possible to discriminate between such contact terms and the alternative explanation in terms of leptoquark exchange.
1212.3071
Koichi Kanazawa
Koichi Kanazawa and Yuji Koike
Single transverse-spin asymmetry for direct-photon and single-jet productions at RHIC
9 pages, 5 figures; Phys. Lett. B in press
null
10.1016/j.physletb.2013.01.071
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the single transverse-spin asymmetry for the inclusive direct-photon and single-jet productions in the proton-proton collision based on the twist-3 mechanism in the collinear factorization. Taking into account all the effects from the twist-3 quark-gluon correlation functions inside a transversely polarized proton, we present a prediction for the asymmetries at the typical RHIC kinematics. In both processes we find sizable asymmetries in the forward region of the polarized proton while they are almost zero in the backward region. This implies that if one finds a nonzero asymmetries in the backward region in these processes, it should be ascribed wholely to the three-gluon correlations. We also find the soft-gluon pole contribution is dominant and the soft-fermion pole contribution is negligible in the whole Feynman-x region for these asymmetries.
[ { "created": "Thu, 13 Dec 2012 07:23:01 GMT", "version": "v1" }, { "created": "Thu, 7 Feb 2013 08:39:45 GMT", "version": "v2" } ]
2015-06-12
[ [ "Kanazawa", "Koichi", "" ], [ "Koike", "Yuji", "" ] ]
We study the single transverse-spin asymmetry for the inclusive direct-photon and single-jet productions in the proton-proton collision based on the twist-3 mechanism in the collinear factorization. Taking into account all the effects from the twist-3 quark-gluon correlation functions inside a transversely polarized proton, we present a prediction for the asymmetries at the typical RHIC kinematics. In both processes we find sizable asymmetries in the forward region of the polarized proton while they are almost zero in the backward region. This implies that if one finds a nonzero asymmetries in the backward region in these processes, it should be ascribed wholely to the three-gluon correlations. We also find the soft-gluon pole contribution is dominant and the soft-fermion pole contribution is negligible in the whole Feynman-x region for these asymmetries.
2105.04277
Durmus Demir
Durmus Demir
Naturally-Coupled Dark Sectors
17 pages, 6 figures, 1 table. A review to appear in MDPI Galaxies Topical Collection "A Trip Across the Universe: Our Present Knowledge and Future Perspectives"
null
null
null
hep-ph astro-ph.CO astro-ph.GA gr-qc
http://creativecommons.org/licenses/by/4.0/
The dark sector, composed of the fields neutral under the Standard Model (SM) gauge group, can couple to the SM through the Higgs, hypercharge and neutrino portals, and pull the SM towards its scale by loop corrections. This instability, not possible to prevent in the known SM completions like supersymmetry due to their sizable couplings to the SM, calls for alternative mechanisms which can neutralize sensitivities of the SM to the dark sector scale and to the ultraviolet cutoff above it. Here we review such a mechanism in which incorporation of gravity into the SM predicts the existence of a dark sector and allows it to be naturally-coupled to the SM. We discuss and illustrate salient processes which can probe the naturally-coupled dark sectors.
[ { "created": "Mon, 10 May 2021 11:35:59 GMT", "version": "v1" } ]
2021-05-11
[ [ "Demir", "Durmus", "" ] ]
The dark sector, composed of the fields neutral under the Standard Model (SM) gauge group, can couple to the SM through the Higgs, hypercharge and neutrino portals, and pull the SM towards its scale by loop corrections. This instability, not possible to prevent in the known SM completions like supersymmetry due to their sizable couplings to the SM, calls for alternative mechanisms which can neutralize sensitivities of the SM to the dark sector scale and to the ultraviolet cutoff above it. Here we review such a mechanism in which incorporation of gravity into the SM predicts the existence of a dark sector and allows it to be naturally-coupled to the SM. We discuss and illustrate salient processes which can probe the naturally-coupled dark sectors.
hep-ph/9608268
Gg190
Bernd Schwesinger (Siegen University)
Meson photoproduction at threshold in three flavor soliton models
8 pages, LaTeX, no figures
Phys.Lett. B392 (1997) 13-17
10.1016/S0370-2693(96)01518-3
SI-96-TP3S1
hep-ph nucl-th
null
In Skyrme-type models, the leading term of the low-energy photoproduction amplitude is identical to the standard expression and independent of the number of flavors considered, but subleading terms are not.
[ { "created": "Wed, 7 Aug 1996 09:29:22 GMT", "version": "v1" } ]
2009-10-28
[ [ "Schwesinger", "Bernd", "", "Siegen University" ] ]
In Skyrme-type models, the leading term of the low-energy photoproduction amplitude is identical to the standard expression and independent of the number of flavors considered, but subleading terms are not.
0910.2595
Gustavo Gil da Silveira
M.B. Gay Ducati, G.G. Silveira
Diffractive Higgs boson photoproduction in proton-proton collisions
2 pages, 3 figures, to be submitted in XXIX Physics in Collision, Proceedings of the International Symposium in Kobe, Japan, August 30 - September 2, 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new approach for the Higgs boson production by Double Pomeron Exchange (DPE) in the Deeply Virtual Compton Scattering, where a color dipole interacts diffractively with the proton by DPE. Applying it to Peripheral Collisions, we predict a cross section around 0.1 fb, which is similar to that obtained from the $\gamma\gamma$ subprocess. Although this result is lower than the prediction from the KMR approach, our results are competitive with the $\gamma\gamma$ and Pomeron-Pomeron subprocesses with a more precise proposal for the Gap Survival Probability.
[ { "created": "Wed, 14 Oct 2009 12:02:07 GMT", "version": "v1" } ]
2009-10-15
[ [ "Ducati", "M. B. Gay", "" ], [ "Silveira", "G. G.", "" ] ]
We propose a new approach for the Higgs boson production by Double Pomeron Exchange (DPE) in the Deeply Virtual Compton Scattering, where a color dipole interacts diffractively with the proton by DPE. Applying it to Peripheral Collisions, we predict a cross section around 0.1 fb, which is similar to that obtained from the $\gamma\gamma$ subprocess. Although this result is lower than the prediction from the KMR approach, our results are competitive with the $\gamma\gamma$ and Pomeron-Pomeron subprocesses with a more precise proposal for the Gap Survival Probability.
hep-ph/9702260
GLin
Wei-Shu Hou, Guey-Lin Lin, Chien-Yi Ma and C.-P. Yuan
Probing Flavor Changing Neutral Higgs Couplings at LHC
14 pages, REVTEX, 3 figures included
Phys.Lett. B409 (1997) 344-348
10.1016/S0370-2693(97)00921-0
NTUTH-97-01, NCTU-TH-97-01, MSUHEP-70122
hep-ph
null
Uniquely heavy with mass at the weak scale, the top quark may have large flavor changing couplings to Higgs bosons that are as yet unexplored. We show that such couplings can be directly probed at the LHC through the parton subprocess $c(\bar c)g \to t (\bar t)A^0$, where the pseudoscalar $A^0$ subsequently decays into $t \bar c$ or ${\bar t} c$, giving rise to the intriguing final state of like sign top quark pairs. After demanding $\ell^\pm\ell^\pm$, missing energy and two $b$-jets, the major background turns out to be $q\bar q' \to Wt \bar t$, which can be partially suppressed by jet counting. The signal can then manifest itself in the asymmetry of numbers of $\ell^+\ell^+$ and $\ell^-\ell^-$ events. To further improve the signal over background, efficient $t$ vs. $\bar t$ tagging methods should be developed.
[ { "created": "Wed, 5 Feb 1997 15:23:27 GMT", "version": "v1" } ]
2016-09-06
[ [ "Hou", "Wei-Shu", "" ], [ "Lin", "Guey-Lin", "" ], [ "Ma", "Chien-Yi", "" ], [ "Yuan", "C. -P.", "" ] ]
Uniquely heavy with mass at the weak scale, the top quark may have large flavor changing couplings to Higgs bosons that are as yet unexplored. We show that such couplings can be directly probed at the LHC through the parton subprocess $c(\bar c)g \to t (\bar t)A^0$, where the pseudoscalar $A^0$ subsequently decays into $t \bar c$ or ${\bar t} c$, giving rise to the intriguing final state of like sign top quark pairs. After demanding $\ell^\pm\ell^\pm$, missing energy and two $b$-jets, the major background turns out to be $q\bar q' \to Wt \bar t$, which can be partially suppressed by jet counting. The signal can then manifest itself in the asymmetry of numbers of $\ell^+\ell^+$ and $\ell^-\ell^-$ events. To further improve the signal over background, efficient $t$ vs. $\bar t$ tagging methods should be developed.
1106.3390
Hidekazu Tanaka
Hidekazu Tanaka
NLL Order Contributions for Exclusive Processes in Jet-Calculus Scheme
17 pages, 3 figures
Prog. Theor. Phys. 126 (2011), 885-901
10.1143/PTP.126.885
RUP 11-3
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the next-to-leading logarithmic (NLL) order contributions of the quantum chromodynamics (QCD) for exclusive processes evaluated by Monte Carlo methods. Ambiguities of the Monte Carlo calculation based on the leading-logarithmic (LL) order approximations are pointed out. To remove these ambiguities, we take into account the NLL order terms. In a model presented in this paper, interference contributions due to the NLL order terms are included for the generation of the transverse momenta in initial-state parton radiations. Furthermore, a kinematical constraint due to parton radiation, which is also a part of the NLL order contributions, is taken into account. This method guarantees a proper phase space boundary for hard scattering cross sections as well as parton radiations. As an example, cross sections for lepton pair productions mediated by a virtual photon in hadron-hadron collisions are calculated, using the jet-calculus scheme for flavor nonsinglet quarks.
[ { "created": "Fri, 17 Jun 2011 06:10:48 GMT", "version": "v1" }, { "created": "Mon, 5 Dec 2011 09:06:12 GMT", "version": "v2" } ]
2011-12-06
[ [ "Tanaka", "Hidekazu", "" ] ]
We investigate the next-to-leading logarithmic (NLL) order contributions of the quantum chromodynamics (QCD) for exclusive processes evaluated by Monte Carlo methods. Ambiguities of the Monte Carlo calculation based on the leading-logarithmic (LL) order approximations are pointed out. To remove these ambiguities, we take into account the NLL order terms. In a model presented in this paper, interference contributions due to the NLL order terms are included for the generation of the transverse momenta in initial-state parton radiations. Furthermore, a kinematical constraint due to parton radiation, which is also a part of the NLL order contributions, is taken into account. This method guarantees a proper phase space boundary for hard scattering cross sections as well as parton radiations. As an example, cross sections for lepton pair productions mediated by a virtual photon in hadron-hadron collisions are calculated, using the jet-calculus scheme for flavor nonsinglet quarks.
1802.00062
Mikl\'os Z\'et\'enyi
Mikl\'os Z\'et\'enyi, Enrico Speranza and Bengt Friman
Polarization and dilepton angular distribution in pion-nucleon collisions
Presented at the NSTAR2017 conference
null
10.1007/s00601-018-1461-0
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study hadronic polarization and the related anisotropy of the dilepton angular distribution for the reaction $\pi N \to Ne^+e^-$. We employ consistent effective interactions for baryon resonances up to spin-5/2 to compute their contribution to the anisotropy coefficient. We show that the spin and parity of the intermediate baryon resonance is reflected in the angular dependence of the anisotropy coefficient. We present results for the anisotropy coefficient including the $N(1520)$ and $N(1440)$ resonances, which are essential at the collision energy of the recent data obtained by the HADES collaboration on this reaction. We conclude that the anisotropy coefficient provides useful constraints for unraveling the resonance contributions to this process.
[ { "created": "Wed, 31 Jan 2018 20:52:42 GMT", "version": "v1" } ]
2018-11-14
[ [ "Zétényi", "Miklós", "" ], [ "Speranza", "Enrico", "" ], [ "Friman", "Bengt", "" ] ]
We study hadronic polarization and the related anisotropy of the dilepton angular distribution for the reaction $\pi N \to Ne^+e^-$. We employ consistent effective interactions for baryon resonances up to spin-5/2 to compute their contribution to the anisotropy coefficient. We show that the spin and parity of the intermediate baryon resonance is reflected in the angular dependence of the anisotropy coefficient. We present results for the anisotropy coefficient including the $N(1520)$ and $N(1440)$ resonances, which are essential at the collision energy of the recent data obtained by the HADES collaboration on this reaction. We conclude that the anisotropy coefficient provides useful constraints for unraveling the resonance contributions to this process.
hep-ph/0409299
Fuminobu Takahashi
A.D. Dolgov, Fuminobu Takahashi
Suppressed neutrino oscillations and large lepton asymmetries
4 pages, 1 figure, talk given by F. Takahashi at the 12th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2004), Tsukuba, Japan, June 17-23, 2004
null
null
null
hep-ph
null
It is shown that hypothetical neutrino-majoron coupling can suppress neutrino flavor oscillations in the early universe, in contrast to the usual weak interaction case. This reopens a window for a noticeable cosmological lepton asymmetry which is forbidden for the large mixing angle solution in the case of standard interactions of neutrinos.
[ { "created": "Mon, 27 Sep 2004 05:21:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dolgov", "A. D.", "" ], [ "Takahashi", "Fuminobu", "" ] ]
It is shown that hypothetical neutrino-majoron coupling can suppress neutrino flavor oscillations in the early universe, in contrast to the usual weak interaction case. This reopens a window for a noticeable cosmological lepton asymmetry which is forbidden for the large mixing angle solution in the case of standard interactions of neutrinos.
hep-ph/0610031
Boris Kerbikov
B.Kerbikov
Crossover, Fluctuations and Anderson Transition in Quark Matter Formation
Talk at ICHEP'06, Moscow, 26 July - 2 August 2006
null
null
null
hep-ph
null
We argue that there is a unique transition state of moderate density between the nuclear matter and superconducting quark matter alternatives. The distinguishing features of this state are discussed.
[ { "created": "Tue, 3 Oct 2006 12:10:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kerbikov", "B.", "" ] ]
We argue that there is a unique transition state of moderate density between the nuclear matter and superconducting quark matter alternatives. The distinguishing features of this state are discussed.
hep-ph/0101117
null
O.G. Tchikilev (IHEP, Protvino)
Koenigs function and branching processes
6 pages, LATEX, sprocl.sty, to be published in Proc. of the ISMD2000, Tihany, Hungary. Editor corrections are included
null
null
null
hep-ph
null
An explicit solution of time-homogeneous pure birth branching processes is described. It gives alternative extensions for the negative binomial distribution (branching processes with immigration) and for the Furry-Yule distribution (branching processes without immigration).
[ { "created": "Thu, 11 Jan 2001 17:13:22 GMT", "version": "v1" }, { "created": "Fri, 9 Feb 2001 07:06:09 GMT", "version": "v2" } ]
2007-05-23
[ [ "Tchikilev", "O. G.", "", "IHEP, Protvino" ] ]
An explicit solution of time-homogeneous pure birth branching processes is described. It gives alternative extensions for the negative binomial distribution (branching processes with immigration) and for the Furry-Yule distribution (branching processes without immigration).
hep-ph/9703385
Javier Magnin
G. Herrera and J. Magnin
Lambda_c/Lambda_c-bar production asymmetries in pp and pi^- p collisions
discussion considerably enlarged. Figs. added. Final version to appear in Eur. Phys. J. C
Eur.Phys.J.C2:477-482,1998
10.1007/s100520050154
CBPF-NF-023/97
hep-ph hep-ex
null
We study Lambda_c/Lambda}_c-bar production asymmetries in pp and pi- p collisions using a recently proposed two component model. The model includes heavy baryon production by the usual mechanism of parton fusion and fragmentation plus recombination of valence and sea quarks from the beam and target hadrons. We compare our results with experimental data on asymmetries measured recently.
[ { "created": "Fri, 21 Mar 1997 13:12:55 GMT", "version": "v1" }, { "created": "Mon, 12 Jan 1998 18:35:33 GMT", "version": "v2" } ]
2011-09-13
[ [ "Herrera", "G.", "" ], [ "Magnin", "J.", "" ] ]
We study Lambda_c/Lambda}_c-bar production asymmetries in pp and pi- p collisions using a recently proposed two component model. The model includes heavy baryon production by the usual mechanism of parton fusion and fragmentation plus recombination of valence and sea quarks from the beam and target hadrons. We compare our results with experimental data on asymmetries measured recently.
1001.2954
Fernando Febres Cordero
Fernando Febres Cordero
Jet and W/Z Production at Hadron Colliders
Invited talk at the XXth Hadron Collider Physics Symposium: HCP 2009, Evian, France, November 16-20 2009
PoS(HCP2009)008
null
SB/F/378-10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The start of the physics program at the LHC has added great impetus in the development of powerful theoretical tools to meet the many challenges that this collider brings. The production of jets and weak vector bosons is at the center of most analyses, from machine performance to new physics searches. In this talk we review some recent advances in the study of jets, in the computation of quantum corrections to processes with large jet multiplicity and their impact in W/Z+jets and W/Z+b-jets production at the Tevatron and the LHC.
[ { "created": "Mon, 18 Jan 2010 04:38:02 GMT", "version": "v1" } ]
2010-03-24
[ [ "Cordero", "Fernando Febres", "" ] ]
The start of the physics program at the LHC has added great impetus in the development of powerful theoretical tools to meet the many challenges that this collider brings. The production of jets and weak vector bosons is at the center of most analyses, from machine performance to new physics searches. In this talk we review some recent advances in the study of jets, in the computation of quantum corrections to processes with large jet multiplicity and their impact in W/Z+jets and W/Z+b-jets production at the Tevatron and the LHC.
1702.04526
Kunio Kaneta
Kenji Kadota and Kunio Kaneta
Sterile neutrino dark matter from right-handed neutrino oscillations
Version to appear in PRD
Phys. Rev. D 97, 115021 (2018)
10.1103/PhysRevD.97.115021
CTPU-17-04
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a scenario where sterile neutrino (either warm or cold) dark matter (DM) is produced through (nonresonant) oscillations among right-handed neutrinos (RHNs) and can constitute the whole DM in the Universe, in contrast to the conventional sterile neutrino production through its mixing with the left-handed neutrinos. The lightest RHN can be sterile neutrino DM whose mixing with left-handed neutrinos is sufficiently small while heavier RHNs can have non-negligible mixings with left-handed neutrinos to explain the neutrino masses by the seesaw mechanism. We also demonstrate that, in our scenario, the production of sterile RHN DM from the decay of a heavier RHN is subdominant compared with the RHN oscillation production due to the X-ray and small-scale structure constraints.
[ { "created": "Wed, 15 Feb 2017 10:04:02 GMT", "version": "v1" }, { "created": "Thu, 21 Jun 2018 17:02:43 GMT", "version": "v2" } ]
2018-06-22
[ [ "Kadota", "Kenji", "" ], [ "Kaneta", "Kunio", "" ] ]
We study a scenario where sterile neutrino (either warm or cold) dark matter (DM) is produced through (nonresonant) oscillations among right-handed neutrinos (RHNs) and can constitute the whole DM in the Universe, in contrast to the conventional sterile neutrino production through its mixing with the left-handed neutrinos. The lightest RHN can be sterile neutrino DM whose mixing with left-handed neutrinos is sufficiently small while heavier RHNs can have non-negligible mixings with left-handed neutrinos to explain the neutrino masses by the seesaw mechanism. We also demonstrate that, in our scenario, the production of sterile RHN DM from the decay of a heavier RHN is subdominant compared with the RHN oscillation production due to the X-ray and small-scale structure constraints.
hep-ph/0608306
Bernd Kniehl
Bernd A. Kniehl, Alberto Sirlin
Simple Approach to Renormalize the Cabibbo-Kobayashi-Maskawa Matrix
9 pages, 1 figure, minor changes in the text, new reference included, to appear in Phys. Rev. Lett
Phys.Rev.Lett.97:221801,2006
10.1103/PhysRevLett.97.221801
DESY 06-141, MPP-2006-108, NYU-TH/06/08/29
hep-ph hep-th
null
We present an on-shell scheme to renormalize the Cabibbo-Kobayashi-Maskawa (CKM) matrix. It is based on a novel procedure to separate the external-leg mixing corrections into gauge-independent self-mass and gauge-dependent wave-function renormalization contributions, and to implement the on-shell renormalization of the former with non-diagonal mass counterterm matrices. Diagonalization of the complete mass matrix leads to an explicit CKM counterterm matrix, which automatically satisfies all the following important properties: it is gauge independent, preserves unitarity, and leads to renormalized amplitudes that are non-singular in the limit in which any two fermions become mass degenerate.
[ { "created": "Tue, 29 Aug 2006 15:35:55 GMT", "version": "v1" }, { "created": "Fri, 20 Oct 2006 09:55:06 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kniehl", "Bernd A.", "" ], [ "Sirlin", "Alberto", "" ] ]
We present an on-shell scheme to renormalize the Cabibbo-Kobayashi-Maskawa (CKM) matrix. It is based on a novel procedure to separate the external-leg mixing corrections into gauge-independent self-mass and gauge-dependent wave-function renormalization contributions, and to implement the on-shell renormalization of the former with non-diagonal mass counterterm matrices. Diagonalization of the complete mass matrix leads to an explicit CKM counterterm matrix, which automatically satisfies all the following important properties: it is gauge independent, preserves unitarity, and leads to renormalized amplitudes that are non-singular in the limit in which any two fermions become mass degenerate.
2407.21179
Anish Ghoshal
Arpan Chatterjee, Marco Frasca, Anish Ghoshal and Stefan Groote
Dynamical generation of electroweak scale from the conformal sector: A strongly coupled Higgs via the Dyson--Schwinger approach
4 pages + Appedix + References, 1 Figure; comments are welcome
null
null
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel pathway to generate the electroweak (EW) scale via non-perturbative dynamics of a conformally invariant scalar sector at the classical level. We provide a method to estimate the non-perturbative EW scale generation using the exact solution of the background equations of motion in a scalar theory via the Dyson-Schwinger approach. Particularly, we find an analytical result for the Higgs mass in the strongly coupled regime in terms of its quartic self interaction term and the cut-off scale of the theory. We also show that the Higgs sector is an essential part of the Standard Model as, without it, a Yang--Mills gauge theory cannot acquire mass even if a self-interaction term is present. Our analysis lead to a more realistic model building with possible solutions to the gauge hierarchy problem and, in general, to the dynamical generation of any scales scales in nature, be it the visible sector or the dark sector.
[ { "created": "Tue, 30 Jul 2024 20:34:06 GMT", "version": "v1" } ]
2024-08-01
[ [ "Chatterjee", "Arpan", "" ], [ "Frasca", "Marco", "" ], [ "Ghoshal", "Anish", "" ], [ "Groote", "Stefan", "" ] ]
We propose a novel pathway to generate the electroweak (EW) scale via non-perturbative dynamics of a conformally invariant scalar sector at the classical level. We provide a method to estimate the non-perturbative EW scale generation using the exact solution of the background equations of motion in a scalar theory via the Dyson-Schwinger approach. Particularly, we find an analytical result for the Higgs mass in the strongly coupled regime in terms of its quartic self interaction term and the cut-off scale of the theory. We also show that the Higgs sector is an essential part of the Standard Model as, without it, a Yang--Mills gauge theory cannot acquire mass even if a self-interaction term is present. Our analysis lead to a more realistic model building with possible solutions to the gauge hierarchy problem and, in general, to the dynamical generation of any scales scales in nature, be it the visible sector or the dark sector.
2308.16224
Bibhushan Shakya
Bibhushan Shakya
Aspects of Particle Production from Bubble Dynamics at a First Order Phase Transition
20 pages, 2 figures
null
null
DESY 23-125
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First order phase transitions (FOPTs) constitute an active area of contemporary research as a promising cosmological source of observable gravitational waves. The spacetime dynamics of the background scalar field undergoing the phase transition can also directly produce quanta of particles that couple to the scalar, which has not been studied as extensively in the literature. This paper provides the first careful examination of various important aspects of this phenomenon. In particular, the contributions from various stages of FOPTs (bubble nucleation, expansion, collision) are disentangled. It is demonstrated that heavy particles primarily originate from the relative motion of bubble walls at distances comparable to the Compton wavelength of the particle rather than from the bubble collision itself. Subtleties related to non-universality of particle interactions and masses in different vacua are discussed, and a prescription to choose the correct vacuum for the calculation is provided. The suppression of non-perturbative effects such as tachyonic instability and parametric resonance due to the inhomegeneous nature of the process is examined.
[ { "created": "Wed, 30 Aug 2023 18:00:01 GMT", "version": "v1" } ]
2023-09-01
[ [ "Shakya", "Bibhushan", "" ] ]
First order phase transitions (FOPTs) constitute an active area of contemporary research as a promising cosmological source of observable gravitational waves. The spacetime dynamics of the background scalar field undergoing the phase transition can also directly produce quanta of particles that couple to the scalar, which has not been studied as extensively in the literature. This paper provides the first careful examination of various important aspects of this phenomenon. In particular, the contributions from various stages of FOPTs (bubble nucleation, expansion, collision) are disentangled. It is demonstrated that heavy particles primarily originate from the relative motion of bubble walls at distances comparable to the Compton wavelength of the particle rather than from the bubble collision itself. Subtleties related to non-universality of particle interactions and masses in different vacua are discussed, and a prescription to choose the correct vacuum for the calculation is provided. The suppression of non-perturbative effects such as tachyonic instability and parametric resonance due to the inhomegeneous nature of the process is examined.
hep-ph/9902279
Carlo Ewerz
V. N. Gribov
The theory of quark confinement
28 pages, Latex, 54 figures, uses epsfig, amsmath
Eur.Phys.J.C10:91-105,1999
10.1007/s100529900052
Bonn TK 98-09
hep-ph
null
This is the second of the two last papers by V. N. Gribov concluding his 20 year long study of the problem of quark confinement in QCD. In this paper the analytic structure of quark and gluon Green's functions is investigated in the framework of the theory of confinement based on the phenomenon of supercritical binding of light quarks. The problem of unitarity in a confining theory is discussed. The write-up remained unfinished and so it is presented here. The author was planning to considerably extend the paper. The text was prepared for publication by Yu. Dokshitzer, C. Ewerz, and J. Nyiri.
[ { "created": "Tue, 9 Feb 1999 15:15:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gribov", "V. N.", "" ] ]
This is the second of the two last papers by V. N. Gribov concluding his 20 year long study of the problem of quark confinement in QCD. In this paper the analytic structure of quark and gluon Green's functions is investigated in the framework of the theory of confinement based on the phenomenon of supercritical binding of light quarks. The problem of unitarity in a confining theory is discussed. The write-up remained unfinished and so it is presented here. The author was planning to considerably extend the paper. The text was prepared for publication by Yu. Dokshitzer, C. Ewerz, and J. Nyiri.
1010.3065
Takeshi Araki
Takeshi Araki, Jianwei Mei, Zhi-zhong Xing
Intrinsic Deviation from the Tri-bimaximal Neutrino Mixing in a Class of A_4 Flavor Models
11 pages, no figures; a reference added, accepted for publication in Phys. Lett. B
Phys.Lett.B695:165-168,2011
10.1016/j.physletb.2010.10.061
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that the tri-bimaximal neutrino mixing pattern V_0 can be derived from a class of flavor models with the non-Abelian A_4 symmetry. We point out that small corrections to V_0, which are inherent in the A_4 models and arise from both the charged-lepton and neutrino sectors, have been omitted in the previous works. We show that such corrections may lead the 3 \times 3 neutrino mixing matrix V to a non-unitary deviation from V_0, but they cannot result in a nonzero value of \theta_13 or any new CP-violating phases. Current experimental constraints on the unitarity of V allow us to constrain the model parameters to some extent.
[ { "created": "Fri, 15 Oct 2010 03:03:15 GMT", "version": "v1" }, { "created": "Mon, 1 Nov 2010 09:51:46 GMT", "version": "v2" } ]
2011-01-27
[ [ "Araki", "Takeshi", "" ], [ "Mei", "Jianwei", "" ], [ "Xing", "Zhi-zhong", "" ] ]
It is well known that the tri-bimaximal neutrino mixing pattern V_0 can be derived from a class of flavor models with the non-Abelian A_4 symmetry. We point out that small corrections to V_0, which are inherent in the A_4 models and arise from both the charged-lepton and neutrino sectors, have been omitted in the previous works. We show that such corrections may lead the 3 \times 3 neutrino mixing matrix V to a non-unitary deviation from V_0, but they cannot result in a nonzero value of \theta_13 or any new CP-violating phases. Current experimental constraints on the unitarity of V allow us to constrain the model parameters to some extent.
hep-ph/0511244
Andrew Coulthurst
Andrew Coulthurst
Generating the Baryon Asymmetry of the Universe in Split Fermion Models
17 pages, 3 figures; References added; Minor changes, Accepted for publication in Phys. Rev. D
Phys.Rev. D73 (2006) 103517
10.1103/PhysRevD.73.103517
null
hep-ph
null
The origin of the matter-antimatter asymmetry of the universe is one of the major unsolved problems in cosmology and particle physics. In this paper, we investigate the recently proposed possibility that split fermion models -- extra dimensional models where the standard model fermions are localized to different points around the extra dimension -- could provide a means to generate this asymmetry during the phase transition of the localizing scalars. After setting up the scenario that we consider, we use a single fermion toy model to estimate the reflection coefficients for scattering off the phase boundary using a more realistic scalar profile than previous work resulting in a different Kaluza Klein spectrum. The value we calculate for $n_B/s$ is consistent with the mechanism being the source of the baryon asymmetry of our universe provided the $B-L$ violating processes have an efficiency of order $10^{-5}$.
[ { "created": "Mon, 21 Nov 2005 03:35:31 GMT", "version": "v1" }, { "created": "Tue, 6 Dec 2005 01:06:04 GMT", "version": "v2" }, { "created": "Fri, 12 May 2006 02:05:36 GMT", "version": "v3" } ]
2009-11-11
[ [ "Coulthurst", "Andrew", "" ] ]
The origin of the matter-antimatter asymmetry of the universe is one of the major unsolved problems in cosmology and particle physics. In this paper, we investigate the recently proposed possibility that split fermion models -- extra dimensional models where the standard model fermions are localized to different points around the extra dimension -- could provide a means to generate this asymmetry during the phase transition of the localizing scalars. After setting up the scenario that we consider, we use a single fermion toy model to estimate the reflection coefficients for scattering off the phase boundary using a more realistic scalar profile than previous work resulting in a different Kaluza Klein spectrum. The value we calculate for $n_B/s$ is consistent with the mechanism being the source of the baryon asymmetry of our universe provided the $B-L$ violating processes have an efficiency of order $10^{-5}$.
0809.2892
Jens O. Andersen
Jens O. Andersen
Bose-Einstein condensation in dense quark matter
Talk given at Strong and Electroweak matter 2008, Amsterdam August 25-29 2008. Four pages and two figures. 2nd version: typos fixed and updated list of refs
null
10.1016/j.nuclphysa.2009.01.042
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of Bose condensation of charged pions in QCD at finite isospin chemical potential $\mu_I$ using the O(4)-symmetric linear sigma model as an effective field theory for two-flavor QCD. Using the 2PI $1/N$-expansion, we determine the quasiparticle masses as well as the pion and chiral condensates as a function of the temperature and isospin chemical potential in the chiral limit and at the physical point. At T=0, Bose condensation takes place for chemical potentials larger than $m_{\pi}$. In the chiral limit, the chiral condensate vanishes for any finite value of $\mu_I$.
[ { "created": "Wed, 17 Sep 2008 10:30:28 GMT", "version": "v1" }, { "created": "Thu, 23 Oct 2008 06:25:20 GMT", "version": "v2" } ]
2009-11-13
[ [ "Andersen", "Jens O.", "" ] ]
We consider the problem of Bose condensation of charged pions in QCD at finite isospin chemical potential $\mu_I$ using the O(4)-symmetric linear sigma model as an effective field theory for two-flavor QCD. Using the 2PI $1/N$-expansion, we determine the quasiparticle masses as well as the pion and chiral condensates as a function of the temperature and isospin chemical potential in the chiral limit and at the physical point. At T=0, Bose condensation takes place for chemical potentials larger than $m_{\pi}$. In the chiral limit, the chiral condensate vanishes for any finite value of $\mu_I$.
hep-ph/9905339
Bryan Webber
Yu.L. Dokshitzer, G. Marchesini and B.R. Webber
Non-perturbative effects in the energy-energy correlation
41 pages, LaTeX, 4 figures, uses JHEP.cls
JHEP 9907:012,1999
10.1088/1126-6708/1999/07/012
Bicocca-FT-99/01, Cavendish-HEP-99/01
hep-ph
null
The fully resummed next-to-leading-order perturbative calculation of the energy-energy correlation in $e^+e^-$ annihilation is extended to include the leading non-perturbative power-behaved contributions computed using the ``dispersive method'' applied earlier to event shape variables. The correlation between a leading (anti)quark and a gluon produces a non-perturbative 1/Q contribution, while non-perturbative effects in the quark-antiquark correlation give rise to a smaller contribution $\ln Q^2/Q^2$. In the back-to-back region, the power-suppressed contributions actually decrease much more slowly, as small non-integer powers of 1/Q, as a result of the interplay with perturbative effects. The hypothesis of a universal low-energy form for the strong coupling relates the coefficients of these contributions to those measured for other observables.
[ { "created": "Fri, 14 May 1999 09:03:42 GMT", "version": "v1" } ]
2014-11-17
[ [ "Dokshitzer", "Yu. L.", "" ], [ "Marchesini", "G.", "" ], [ "Webber", "B. R.", "" ] ]
The fully resummed next-to-leading-order perturbative calculation of the energy-energy correlation in $e^+e^-$ annihilation is extended to include the leading non-perturbative power-behaved contributions computed using the ``dispersive method'' applied earlier to event shape variables. The correlation between a leading (anti)quark and a gluon produces a non-perturbative 1/Q contribution, while non-perturbative effects in the quark-antiquark correlation give rise to a smaller contribution $\ln Q^2/Q^2$. In the back-to-back region, the power-suppressed contributions actually decrease much more slowly, as small non-integer powers of 1/Q, as a result of the interplay with perturbative effects. The hypothesis of a universal low-energy form for the strong coupling relates the coefficients of these contributions to those measured for other observables.
hep-ph/9308367
Dudas
E.A.Dudas
Dynamical Symmetry Breaking In A Nambu-Jona-Lasinio Model And The Vacuum Structure
7pages
Phys.Lett. B318 (1993) 476-480
10.1016/0370-2693(93)91542-U
null
hep-ph
null
The vacuum structure for a Nambu-Jona -Lasinio type model is studied using the effective potential approach. The relevant degrees of freedom are taken to be two different sets of static, auxiliary fields with different symmetry properties, related by Fierz transformations in the action. The results are compared with the analysis of the Dyson-Schwinger equations in the one-loop approximation.
[ { "created": "Tue, 31 Aug 1993 14:50:44 GMT", "version": "v1" } ]
2009-10-22
[ [ "Dudas", "E. A.", "" ] ]
The vacuum structure for a Nambu-Jona -Lasinio type model is studied using the effective potential approach. The relevant degrees of freedom are taken to be two different sets of static, auxiliary fields with different symmetry properties, related by Fierz transformations in the action. The results are compared with the analysis of the Dyson-Schwinger equations in the one-loop approximation.
0806.3266
Frank Daniel Steffen
Frank Daniel Steffen
Probing the Reheating Temperature at Colliders and with Primordial Nucleosynthesis
10 pages, 3 figures; revised version (references added, minor corrections)
Phys.Lett.B669:74-80,2008
10.1016/j.physletb.2008.09.036
MPP-2008-58
hep-ph astro-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considering gravitino dark matter scenarios with a long-lived charged slepton, we show that collider measurements of the slepton mass and its lifetime can probe not only the gravitino mass but also the post-inflationary reheating temperature TR. In a model independent way, we derive upper limits on TR and discuss them in light of the constraints from the primordial catalysis of lithium-6 through bound-state effects. In the collider-friendly region of slepton masses below 1 TeV, the obtained conservative estimate of the maximum reheating temperature is about TR=3\times 10^9 GeV for the limiting case of a small gluino-slepton mass splitting and about TR=10^8 GeV for the case that is typical for universal soft supersymmetry breaking parameters at the scale of grand unification. We find that a determination of the gluino-slepton mass ratio at the Large Hadron Collider will test the possibility of TR>10^9 GeV and thereby the viability of thermal leptogenesis with hierarchical heavy right-handed Majorana neutrinos.
[ { "created": "Thu, 19 Jun 2008 19:49:07 GMT", "version": "v1" }, { "created": "Wed, 9 Jul 2008 19:56:13 GMT", "version": "v2" } ]
2008-11-26
[ [ "Steffen", "Frank Daniel", "" ] ]
Considering gravitino dark matter scenarios with a long-lived charged slepton, we show that collider measurements of the slepton mass and its lifetime can probe not only the gravitino mass but also the post-inflationary reheating temperature TR. In a model independent way, we derive upper limits on TR and discuss them in light of the constraints from the primordial catalysis of lithium-6 through bound-state effects. In the collider-friendly region of slepton masses below 1 TeV, the obtained conservative estimate of the maximum reheating temperature is about TR=3\times 10^9 GeV for the limiting case of a small gluino-slepton mass splitting and about TR=10^8 GeV for the case that is typical for universal soft supersymmetry breaking parameters at the scale of grand unification. We find that a determination of the gluino-slepton mass ratio at the Large Hadron Collider will test the possibility of TR>10^9 GeV and thereby the viability of thermal leptogenesis with hierarchical heavy right-handed Majorana neutrinos.
hep-ph/9903324
Shinta Kasuya
S. Kasuya and M. Kawasaki
Remarks on Cosmic String Formation during Preheating on Lattice Simulations
7 pages, RevTex, 14 postscript figures included, to appear in Phys. Rev. D
Phys.Rev. D61 (2000) 083510
10.1103/PhysRevD.61.083510
null
hep-ph
null
We reconsider the formation of (global) cosmic strings during and after preheating by calculating the dynamics of a scalar field on both two- and three- dimensional lattices. We have found that there is little differences between the results in two and three dimensions about the dynamics of fluctuations, at least, during preheating. Practically, it is difficult to determine whether long cosmic strings which may affect the later evolution of the universe could ever be produced from the results of simulations on three-dimensional lattices with smaller box sizes than the horizon. Therefore, using two-dimensional lattices with large box size, we have found that cosmic strings with the breaking scale 0\eta \sim 10^{16} GeV are produced for broad range of parameter space in \eta, while for higher breaking scales (\eta \sim 3\times 10^{16} GeV), their production depends crucially on the value of the breaking scale \eta in our simulations.
[ { "created": "Thu, 11 Mar 1999 11:26:50 GMT", "version": "v1" }, { "created": "Wed, 28 Apr 1999 12:20:42 GMT", "version": "v2" }, { "created": "Fri, 28 May 1999 11:07:56 GMT", "version": "v3" }, { "created": "Thu, 4 Nov 1999 15:27:45 GMT", "version": "v4" }, { "cr...
2009-10-31
[ [ "Kasuya", "S.", "" ], [ "Kawasaki", "M.", "" ] ]
We reconsider the formation of (global) cosmic strings during and after preheating by calculating the dynamics of a scalar field on both two- and three- dimensional lattices. We have found that there is little differences between the results in two and three dimensions about the dynamics of fluctuations, at least, during preheating. Practically, it is difficult to determine whether long cosmic strings which may affect the later evolution of the universe could ever be produced from the results of simulations on three-dimensional lattices with smaller box sizes than the horizon. Therefore, using two-dimensional lattices with large box size, we have found that cosmic strings with the breaking scale 0\eta \sim 10^{16} GeV are produced for broad range of parameter space in \eta, while for higher breaking scales (\eta \sim 3\times 10^{16} GeV), their production depends crucially on the value of the breaking scale \eta in our simulations.
2403.15545
Tom Magorsch
Nora Brambilla, Tom Magorsch, Michael Strickland, Antonio Vairo, Peter Vander Griend
Bottomonium suppression from the three-loop QCD potential
15 pages, 3 figures, 1 table
null
null
TUM-EFT 186/23; FERMILAB-PUB-24-0029-V
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We compute the suppression of bottomonium in the quark-gluon plasma using the three-loop QCD static potential. The potential describes the spin-averaged bottomonium spectrum below threshold with a less than 1% error. Within potential nonrelativistic quantum chromodynamics and an open quantum systems framework, we compute the evolution of the bottomonium density matrix. The values of the quarkonium transport coefficients are obtained from lattice QCD measurements of the bottomonium in-medium width and thermal mass shift; we additionally include for the first time a vacuum contribution to the dispersive coefficient ${\gamma}$. Using the three-loop potential and the values of the heavy quarkonium transport coefficients, we find that the resulting bottomonium nuclear modification factor is consistent with experimental observations, while at the same time reproducing the lattice measurements of the in-medium width.
[ { "created": "Fri, 22 Mar 2024 18:00:36 GMT", "version": "v1" } ]
2024-03-26
[ [ "Brambilla", "Nora", "" ], [ "Magorsch", "Tom", "" ], [ "Strickland", "Michael", "" ], [ "Vairo", "Antonio", "" ], [ "Griend", "Peter Vander", "" ] ]
We compute the suppression of bottomonium in the quark-gluon plasma using the three-loop QCD static potential. The potential describes the spin-averaged bottomonium spectrum below threshold with a less than 1% error. Within potential nonrelativistic quantum chromodynamics and an open quantum systems framework, we compute the evolution of the bottomonium density matrix. The values of the quarkonium transport coefficients are obtained from lattice QCD measurements of the bottomonium in-medium width and thermal mass shift; we additionally include for the first time a vacuum contribution to the dispersive coefficient ${\gamma}$. Using the three-loop potential and the values of the heavy quarkonium transport coefficients, we find that the resulting bottomonium nuclear modification factor is consistent with experimental observations, while at the same time reproducing the lattice measurements of the in-medium width.
1109.2869
Sarah Andreas
S. Andreas, M. D. Goodsell and A. Ringwald
Dark Matter and Dark Forces from a supersymmetric hidden sector
40 pages, 11 figures comprising 21 plots. 4Mb total size. v2: figures and references updated; typos removed; some extra explanations added. Matches version published in PRD
Phys.Rev.D87:025007,2013
10.1103/PhysRevD.87.025007
DESY 11-159
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that supersymmetric "Dark Force" models with gravity mediation are viable. To this end, we analyse a simple string-inspired supersymmetric hidden sector model that interacts with the visible sector via kinetic mixing of a light Abelian gauge boson with the hypercharge. We include all induced interactions with the visible sector such as neutralino mass mixing and the Higgs portal term. We perform a detailed parameter space scan comparing the produced dark matter relic abundance and direct detection cross sections to current experiments.
[ { "created": "Tue, 13 Sep 2011 18:02:07 GMT", "version": "v1" }, { "created": "Sun, 20 Jan 2013 08:32:34 GMT", "version": "v2" } ]
2013-01-22
[ [ "Andreas", "S.", "" ], [ "Goodsell", "M. D.", "" ], [ "Ringwald", "A.", "" ] ]
We show that supersymmetric "Dark Force" models with gravity mediation are viable. To this end, we analyse a simple string-inspired supersymmetric hidden sector model that interacts with the visible sector via kinetic mixing of a light Abelian gauge boson with the hypercharge. We include all induced interactions with the visible sector such as neutralino mass mixing and the Higgs portal term. We perform a detailed parameter space scan comparing the produced dark matter relic abundance and direct detection cross sections to current experiments.
hep-ph/9911230
null
Y. S. Kim
Two-pearl Strings: Feynman's Oscillators
RevTex 21 pages, 5 psfigs, presented at the 22nd International Workshop on the Fundamental Problems of High Energy Physics and Field Theory (Protvino, Russia, June 1999), to be published in the proceedings
null
null
null
hep-ph hep-th nucl-th quant-ph
null
String models are designed to provide a covariant description of internal space-time structure of relativistic particles. The string is a limiting case of a series of massive beads like a pearl necklace. In the limit of infinite-number of zero-mass beads, it becomes a field-theoretic string. Another interesting limit is to keep only two pearls by eliminating all others, resulting in a harmonic oscillator. The basic strength of the oscillator model is its mathematical simplicity. This encourages us to construct two-pearl strings for a covariant picture of relativistic extended particles. We achieve this goal by transforming the oscillator model of Feynman {\it et al.} into a representation of the Poincar\'e group. We then construct representations of the O(3)-like little group for those oscillator states, which dictates their internal space-time symmetry of massive particles. This simple mathematical procedure allows us to explain what we observe in the world in terms of the fundamental space-time symmetries, and the built-in covariance of the model allows us to use the physics in the rest frame in order to explain what happens in the infinite-momentum frame. It is thus possible to calculate the parton distribution within the proton moving light-like speed in terms of the quark wave function in its rest frame.
[ { "created": "Thu, 4 Nov 1999 03:28:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kim", "Y. S.", "" ] ]
String models are designed to provide a covariant description of internal space-time structure of relativistic particles. The string is a limiting case of a series of massive beads like a pearl necklace. In the limit of infinite-number of zero-mass beads, it becomes a field-theoretic string. Another interesting limit is to keep only two pearls by eliminating all others, resulting in a harmonic oscillator. The basic strength of the oscillator model is its mathematical simplicity. This encourages us to construct two-pearl strings for a covariant picture of relativistic extended particles. We achieve this goal by transforming the oscillator model of Feynman {\it et al.} into a representation of the Poincar\'e group. We then construct representations of the O(3)-like little group for those oscillator states, which dictates their internal space-time symmetry of massive particles. This simple mathematical procedure allows us to explain what we observe in the world in terms of the fundamental space-time symmetries, and the built-in covariance of the model allows us to use the physics in the rest frame in order to explain what happens in the infinite-momentum frame. It is thus possible to calculate the parton distribution within the proton moving light-like speed in terms of the quark wave function in its rest frame.
1407.8549
T. Lappi
T. Lappi, A. Dumitru, Y. Nara
Structure of chromomagnetic fields in the glasma
4 pages, 3 figures, talk by TL at the Quark Matter 2014 conference, Darmstadt, Germany, May 19-24
null
10.1016/j.nuclphysa.2014.08.007
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The initial stage of a heavy ion collision is dominated by nonperturbatively strong chromoelectric and -magnetic fields. The spatial Wilson loop provides a gauge invariant observable to probe the dynamics of the longitudinal chromomagnetic field. We discuss recent results from a real time lattice calculation of the area-dependence of the expectation value of the spatial Wilson loop. We show that at relatively early times after the collision, a universal scaling as a function of the area emerges at large distances for very different initial conditions, with a nontrivial critical exponent. A similar behavior has earlier been seen in calculations of the gluon transverse momentum spectrum, which becomes independent of the initial spectrum of gauge fields. We also show the distribution of eigenvalues of the spatial Wilson loop and the fluctuations of its real and imaginary parts.
[ { "created": "Thu, 31 Jul 2014 19:59:59 GMT", "version": "v1" } ]
2014-08-20
[ [ "Lappi", "T.", "" ], [ "Dumitru", "A.", "" ], [ "Nara", "Y.", "" ] ]
The initial stage of a heavy ion collision is dominated by nonperturbatively strong chromoelectric and -magnetic fields. The spatial Wilson loop provides a gauge invariant observable to probe the dynamics of the longitudinal chromomagnetic field. We discuss recent results from a real time lattice calculation of the area-dependence of the expectation value of the spatial Wilson loop. We show that at relatively early times after the collision, a universal scaling as a function of the area emerges at large distances for very different initial conditions, with a nontrivial critical exponent. A similar behavior has earlier been seen in calculations of the gluon transverse momentum spectrum, which becomes independent of the initial spectrum of gauge fields. We also show the distribution of eigenvalues of the spatial Wilson loop and the fluctuations of its real and imaginary parts.
hep-ph/9506293
Morris
John M. Cornwall and Duncan A. Morris
Toy Models of Non-perturbative Asymptotic Freedom in $\phi^3_6$
30 pages (REVTeX), 9 figures in uuencoded compressed Postscript
Phys.Rev. D52 (1995) 6074-6086
10.1103/PhysRevD.52.6074
UCLA/95/TEP/20
hep-ph hep-th
null
We study idealizations of the full nonlinear Schwinger-Dyson equations for the asymptotically free theory of $\phi^3$ in six dimensions in its meta-stable vacuum. We begin with the cubic nonlinearity and go on to all-order nonlinearities which contain instanton effects. We show how our toy models of the cubic Schwinger-Dyson equations contain the usual diseases of perturbation theory in the massless limit (e.g., factorially divergent $\beta-$functions, singular Borel-transform kernels associated with infrared renormalons) and show how these models yield specific mechanisms for removing such singularities when there is a mass gap. In the all-order nonlinear equation we show how to recover the usual renormalization-group-improved instanton effects and associated factorial divergences.
[ { "created": "Sun, 11 Jun 1995 23:00:16 GMT", "version": "v1" } ]
2009-10-28
[ [ "Cornwall", "John M.", "" ], [ "Morris", "Duncan A.", "" ] ]
We study idealizations of the full nonlinear Schwinger-Dyson equations for the asymptotically free theory of $\phi^3$ in six dimensions in its meta-stable vacuum. We begin with the cubic nonlinearity and go on to all-order nonlinearities which contain instanton effects. We show how our toy models of the cubic Schwinger-Dyson equations contain the usual diseases of perturbation theory in the massless limit (e.g., factorially divergent $\beta-$functions, singular Borel-transform kernels associated with infrared renormalons) and show how these models yield specific mechanisms for removing such singularities when there is a mass gap. In the all-order nonlinear equation we show how to recover the usual renormalization-group-improved instanton effects and associated factorial divergences.
hep-ph/9312275
Makoto Oka
Ken-ichiro Ogawa, Sachiko Takeuchi and Makoto Oka
Short-range YN interactions in the Quark Cluster Model
talk presented by M. Oka at the JSPS-NSF Joint Seminar on ``Hyperon Nucleon Interactions'', Maui, HI, October, 1993. 9 pp. and 4 figures (Post script files uu-encoded are provided) preprint# TIT/HEP-243/NP
null
null
null
hep-ph nucl-th
null
A phenomenological model for the hyperon-nucleon interactions is constructed by using the quark cluster model approach to the short-distance baryon-baryon interactions. The model contains the SU(3) symmetric meson exchange interaction at large distances and the quark-exchange short-distance interaction. The main feature of the model is that strong channel dependences of the short range repulsions due to the quark model symmetry. It is pointed out that two channels, ($I$, $S$)= (1/2, 0) and (3/2, 1), of the S-wave sigma-nucleon interactions have extremely strong repulsions at short-distances.
[ { "created": "Tue, 14 Dec 1993 03:56:54 GMT", "version": "v1" } ]
2009-09-25
[ [ "Ogawa", "Ken-ichiro", "" ], [ "Takeuchi", "Sachiko", "" ], [ "Oka", "Makoto", "" ] ]
A phenomenological model for the hyperon-nucleon interactions is constructed by using the quark cluster model approach to the short-distance baryon-baryon interactions. The model contains the SU(3) symmetric meson exchange interaction at large distances and the quark-exchange short-distance interaction. The main feature of the model is that strong channel dependences of the short range repulsions due to the quark model symmetry. It is pointed out that two channels, ($I$, $S$)= (1/2, 0) and (3/2, 1), of the S-wave sigma-nucleon interactions have extremely strong repulsions at short-distances.
hep-ph/9906351
Bipin Desai
Bipin R. Desai and Alexander R. Vaucher (University of California, Riverside, CA)
Can the Higgs Boson Bootstrap itself?
24 pages, 5 figures
null
null
UCRHEP-T257
hep-ph
null
It is pointed out that Higgs bootstrap is inherent in the top-condensate models of Nambu and Bardeen et al in that the ladder sum of Higgs pole diagrams in one channel reproduces a Higgs pole in the crossed-channel. This result is exact whenever color flows simultaneously in both channel directions e.g. for N(sub c)=1. Bootstrap solutions for the Higgs boson mass are obtained that are compatible with the condensate models such as the top-color models which imply large top-Yukawa couplings at the top mass.
[ { "created": "Sun, 13 Jun 1999 02:07:59 GMT", "version": "v1" }, { "created": "Thu, 24 Jun 1999 00:07:13 GMT", "version": "v2" } ]
2007-05-23
[ [ "Desai", "Bipin R.", "", "University of California,\n Riverside, CA" ], [ "Vaucher", "Alexander R.", "", "University of California,\n Riverside, CA" ] ]
It is pointed out that Higgs bootstrap is inherent in the top-condensate models of Nambu and Bardeen et al in that the ladder sum of Higgs pole diagrams in one channel reproduces a Higgs pole in the crossed-channel. This result is exact whenever color flows simultaneously in both channel directions e.g. for N(sub c)=1. Bootstrap solutions for the Higgs boson mass are obtained that are compatible with the condensate models such as the top-color models which imply large top-Yukawa couplings at the top mass.
1310.2942
Shaouly Bar-Shalom
Shaouly Bar-Shalom
Dynamical Origin for the 125 GeV Higgs; a Hybrid setup
Talk given at the "European Physical Society Conference on High Energy Physics", EPS-HEP2013, 18-24 July 2013, Stockholm, Sweden. Co-authors: Michael Geller and Amarjit Soni
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a hybrid framework for electroweak symmetry breaking (EWSB), in which the Higgs mechanism is combined with a Nambu-Jona-Lasinio mechanism. The model introduces an unconstrained scalar (i.e., acts as "fundamental" but not the SM field) and a strongly coupled doublet of heavy quarks with a mass around 500 GeV, which forms a condensate at a compositeness scale \Lambda ~ O(1) TeV. This setup is matched at that scale to a tightly constrained hybrid two Higgs doublet model, where both the composite and unconstrained scalars participate in EWSB. This allows us to get a good candidate for the recently observed 125 GeV scalar which has properties very similar to the Standard Model Higgs. The heavier (mostly composite) CP-even scalar has a mass around 500 GeV, while the pseudoscalar and the charged Higgs particles have masses in the range 200 -300 GeV.
[ { "created": "Thu, 10 Oct 2013 20:00:03 GMT", "version": "v1" } ]
2013-10-14
[ [ "Bar-Shalom", "Shaouly", "" ] ]
We describe a hybrid framework for electroweak symmetry breaking (EWSB), in which the Higgs mechanism is combined with a Nambu-Jona-Lasinio mechanism. The model introduces an unconstrained scalar (i.e., acts as "fundamental" but not the SM field) and a strongly coupled doublet of heavy quarks with a mass around 500 GeV, which forms a condensate at a compositeness scale \Lambda ~ O(1) TeV. This setup is matched at that scale to a tightly constrained hybrid two Higgs doublet model, where both the composite and unconstrained scalars participate in EWSB. This allows us to get a good candidate for the recently observed 125 GeV scalar which has properties very similar to the Standard Model Higgs. The heavier (mostly composite) CP-even scalar has a mass around 500 GeV, while the pseudoscalar and the charged Higgs particles have masses in the range 200 -300 GeV.
1806.01659
Ye Xing
Ye Xing and Ruilin Zhu
Weak Decays of Stable Doubly Heavy Tetraquark States
41 pages, 9 figures. To be published in PRD
Phys. Rev. D 98, 053005 (2018)
10.1103/PhysRevD.98.053005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the light of the recent discovery of the $\Xi^{++}_{cc}$ by LHCb collaboration, we study the stable doubly heavy tetraquarks. These states are compact exotic hadrons which can be approximated as the diquark-anti-diquark correlations. In the flavor SU(3) symmetry, they form an SU(3) triplet or anti-sextet. The spectra of the stable doubly heavy tetraquark states are predicted by Sakharov-Zeldovich formula. We find that the $T^+_{cc\bar{u}\bar{d}}({\bf 3})$ is about 16MeV below the $DD^*$ threshold, while $T^{-}_{bb\bar{u}\bar{d}}({\bf 3})$ is about 73MeV below the $BB^*$ threshold. We then study the semileptonic and nonleptonic weak decays of the stable doubly heavy tetraquark states. The decay amplitudes are parametrized in terms of SU(3)-irreducible amplitudes. Ratios between decay widths of different channels are also derived. At the end, we collect the Cabibbo allowed two-body and three-body decay channels, which are most promising to search for the stable doubly heavy tetraquark states at LHCb and Belle II experiments.
[ { "created": "Mon, 4 Jun 2018 11:52:21 GMT", "version": "v1" }, { "created": "Thu, 7 Jun 2018 14:55:47 GMT", "version": "v2" }, { "created": "Mon, 11 Jun 2018 14:46:33 GMT", "version": "v3" }, { "created": "Sat, 22 Sep 2018 08:37:47 GMT", "version": "v4" } ]
2018-10-09
[ [ "Xing", "Ye", "" ], [ "Zhu", "Ruilin", "" ] ]
In the light of the recent discovery of the $\Xi^{++}_{cc}$ by LHCb collaboration, we study the stable doubly heavy tetraquarks. These states are compact exotic hadrons which can be approximated as the diquark-anti-diquark correlations. In the flavor SU(3) symmetry, they form an SU(3) triplet or anti-sextet. The spectra of the stable doubly heavy tetraquark states are predicted by Sakharov-Zeldovich formula. We find that the $T^+_{cc\bar{u}\bar{d}}({\bf 3})$ is about 16MeV below the $DD^*$ threshold, while $T^{-}_{bb\bar{u}\bar{d}}({\bf 3})$ is about 73MeV below the $BB^*$ threshold. We then study the semileptonic and nonleptonic weak decays of the stable doubly heavy tetraquark states. The decay amplitudes are parametrized in terms of SU(3)-irreducible amplitudes. Ratios between decay widths of different channels are also derived. At the end, we collect the Cabibbo allowed two-body and three-body decay channels, which are most promising to search for the stable doubly heavy tetraquark states at LHCb and Belle II experiments.
0907.0770
Genevieve Belanger
G. B\'elanger
Dark matter and the LHC
6 pages, 4 figures, Talk at Dark matter and dark energy, GGI, Florence, Italy, March 2009
Nucl.Phys.Proc.Suppl.194:5-10,2009
10.1016/j.nuclphysbps.2009.07.037
LAPTH-Conf-133/09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmological and astrophysical measurements indicate that the universe contains a large amount of dark matter. A number of weak scale dark matter candidates have been proposed in extensions of the standard model. The potential to discover the dark matter particle and determine its properties at the upcoming LHC is summarized.
[ { "created": "Sat, 4 Jul 2009 15:40:16 GMT", "version": "v1" } ]
2009-12-17
[ [ "Bélanger", "G.", "" ] ]
Cosmological and astrophysical measurements indicate that the universe contains a large amount of dark matter. A number of weak scale dark matter candidates have been proposed in extensions of the standard model. The potential to discover the dark matter particle and determine its properties at the upcoming LHC is summarized.
2402.14441
Yan Shao
Zhen-hua Zhao, Hong-Yu Shi, Yan Shao
Leptogenesis consequences of trimaximal mixing and $\mu$-$\tau$ reflection symmetry in the most minimal seesaw model
24 pages, 10 figures, version accepted for publication in PRD
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper we have studied the realizations of the popular TM1 neutrino mixing and neutrino $\mu$-$\tau$ reflection symmetry (which are well motivated from the neutrino oscillation data and lead to interesting phenomenological consequences) in the most minimal seesaw model with a pseudo-Dirac pair of right-handed neutrinos, and their consequences for leptogenesis. In order to realize the low-scale resonant leptogenesis scenario, we have considered two possible ways of generating the tiny mass splitting between the two right-handed neutrinos: one way is to modify their Majorana mass matrix to a form as shown in Eq. (25); the other way is to consider the renormalization-group corrections for their masses. For the $\mu$-$\tau$ reflection symmetry, in order for leptogenesis to work, we have further considered the flavor-dependent conversion efficiencies from the lepton asymmetry to the baryon asymmetry during the sphaleron processes, and its breaking via the renormalization-group corrections.
[ { "created": "Thu, 22 Feb 2024 10:42:29 GMT", "version": "v1" }, { "created": "Mon, 13 May 2024 08:51:10 GMT", "version": "v2" }, { "created": "Tue, 14 May 2024 06:54:13 GMT", "version": "v3" }, { "created": "Wed, 22 May 2024 10:36:40 GMT", "version": "v4" } ]
2024-05-24
[ [ "Zhao", "Zhen-hua", "" ], [ "Shi", "Hong-Yu", "" ], [ "Shao", "Yan", "" ] ]
In this paper we have studied the realizations of the popular TM1 neutrino mixing and neutrino $\mu$-$\tau$ reflection symmetry (which are well motivated from the neutrino oscillation data and lead to interesting phenomenological consequences) in the most minimal seesaw model with a pseudo-Dirac pair of right-handed neutrinos, and their consequences for leptogenesis. In order to realize the low-scale resonant leptogenesis scenario, we have considered two possible ways of generating the tiny mass splitting between the two right-handed neutrinos: one way is to modify their Majorana mass matrix to a form as shown in Eq. (25); the other way is to consider the renormalization-group corrections for their masses. For the $\mu$-$\tau$ reflection symmetry, in order for leptogenesis to work, we have further considered the flavor-dependent conversion efficiencies from the lepton asymmetry to the baryon asymmetry during the sphaleron processes, and its breaking via the renormalization-group corrections.
2404.12996
Stefan Evans
Stefan Evans, Ralf Sch\"utzhold
Axion-induced Casimir force between nuclei and dynamical axion pair creation
6 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the interaction between axions and nuclei by combining the Peccei-Quinn mechanism with results from quantum chromo-dynamics (QCD) which imply that the QCD condensates are reduced within nuclear matter. Thus, the effective axion mass is also reduced, yielding a finite axion-nucleon scattering cross section. Even in the absence of real axions, this interaction would manifest itself in a Casimir type attraction between two nuclei. Finally, accelerated nuclei can create entangled pairs of axions via the dynamical Casimir effect (or as signatures of the Unruh effect).
[ { "created": "Fri, 19 Apr 2024 16:49:48 GMT", "version": "v1" }, { "created": "Thu, 16 May 2024 14:14:28 GMT", "version": "v2" } ]
2024-05-17
[ [ "Evans", "Stefan", "" ], [ "Schützhold", "Ralf", "" ] ]
We study the interaction between axions and nuclei by combining the Peccei-Quinn mechanism with results from quantum chromo-dynamics (QCD) which imply that the QCD condensates are reduced within nuclear matter. Thus, the effective axion mass is also reduced, yielding a finite axion-nucleon scattering cross section. Even in the absence of real axions, this interaction would manifest itself in a Casimir type attraction between two nuclei. Finally, accelerated nuclei can create entangled pairs of axions via the dynamical Casimir effect (or as signatures of the Unruh effect).
1712.04940
Luca Di Luzio
Luca Di Luzio, Federico Mescia, Enrico Nardi, Paolo Panci, Robert Ziegler
Astrophobic Axions
6 pages, 1 figure. Major revisions and clarifications in the presentation, results unchanged. Title changed as suggested by Journal; references added; version to be published in Phys. Rev. Lett
Phys. Rev. Lett. 120, 261803 (2018)
10.1103/PhysRevLett.120.261803
IPPP/17/102, CERN-TH-2017-256
hep-ph astro-ph.CO astro-ph.SR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a class of axion models with generation dependent Peccei-Quinn charges for the known fermions that allow to suppress the axion couplings to nucleons and electrons. Astrophysical limits are thus relaxed, allowing for axion masses up to ${\cal O}(0.1)$ eV. The axion-photon coupling remains instead sizeable, so that next generation helioscopes will be able to probe this scenario. Astrophobia unavoidably implies flavor violating axion couplings, so that experimental limits on flavour-violating processes can provide complementary probes. The astrophobic axion can be a viable dark matter candidate in the heavy mass window, and can also account for anomalous energy loss in stars.
[ { "created": "Wed, 13 Dec 2017 19:00:00 GMT", "version": "v1" }, { "created": "Wed, 13 Jun 2018 11:31:21 GMT", "version": "v2" } ]
2018-07-04
[ [ "Di Luzio", "Luca", "" ], [ "Mescia", "Federico", "" ], [ "Nardi", "Enrico", "" ], [ "Panci", "Paolo", "" ], [ "Ziegler", "Robert", "" ] ]
We propose a class of axion models with generation dependent Peccei-Quinn charges for the known fermions that allow to suppress the axion couplings to nucleons and electrons. Astrophysical limits are thus relaxed, allowing for axion masses up to ${\cal O}(0.1)$ eV. The axion-photon coupling remains instead sizeable, so that next generation helioscopes will be able to probe this scenario. Astrophobia unavoidably implies flavor violating axion couplings, so that experimental limits on flavour-violating processes can provide complementary probes. The astrophobic axion can be a viable dark matter candidate in the heavy mass window, and can also account for anomalous energy loss in stars.
hep-ph/0007085
Luca Silvestrini
A.J. Buras, P. Gambino, M. Gorbahn, S. Jager and L. Silvestrini
Universal Unitarity Triangle and Physics Beyond the Standard Model
12 pages, 1 figure
Phys.Lett.B500:161-167,2001
10.1016/S0370-2693(01)00061-2
TUM-HEP-379/00
hep-ph
null
We make the simple observation that there exists a universal unitarity triangle for all models, like the SM, the Two Higgs Doublet Models I and II and the MSSM with minimal flavour violation, that do not have any new operators beyond those present in the SM and in which all flavour changing transitions are governed by the CKM matrix with no new phases beyond the CKM phase. This universal triangle can be determined in the near future from the ratio (Delta M)_d/(Delta M)_s and sin(2 beta) measured first through the CP asymmetry in B_d^0 to psi K_S and later in K to pi nu nubar decays. Also suitable ratios of the branching ratios for B to X_{d,s} nu nubar and B_{d,s} to mu^+ mu^- and the angle gamma measured by means of CP asymmetries in B decays can be used for this determination. Comparison of this universal triangle with the non-universal triangles extracted in each model using epsilon, (Delta M)_d and various branching ratios for rare decays will allow to find out in a transparent manner which of these models, if any, is singled out by experiment. A virtue of the universal triangle is that it allows to separate the determination of the CKM parameters from the determination of new parameters present in the extensions of the SM considered here.
[ { "created": "Mon, 10 Jul 2000 16:43:46 GMT", "version": "v1" } ]
2010-11-23
[ [ "Buras", "A. J.", "" ], [ "Gambino", "P.", "" ], [ "Gorbahn", "M.", "" ], [ "Jager", "S.", "" ], [ "Silvestrini", "L.", "" ] ]
We make the simple observation that there exists a universal unitarity triangle for all models, like the SM, the Two Higgs Doublet Models I and II and the MSSM with minimal flavour violation, that do not have any new operators beyond those present in the SM and in which all flavour changing transitions are governed by the CKM matrix with no new phases beyond the CKM phase. This universal triangle can be determined in the near future from the ratio (Delta M)_d/(Delta M)_s and sin(2 beta) measured first through the CP asymmetry in B_d^0 to psi K_S and later in K to pi nu nubar decays. Also suitable ratios of the branching ratios for B to X_{d,s} nu nubar and B_{d,s} to mu^+ mu^- and the angle gamma measured by means of CP asymmetries in B decays can be used for this determination. Comparison of this universal triangle with the non-universal triangles extracted in each model using epsilon, (Delta M)_d and various branching ratios for rare decays will allow to find out in a transparent manner which of these models, if any, is singled out by experiment. A virtue of the universal triangle is that it allows to separate the determination of the CKM parameters from the determination of new parameters present in the extensions of the SM considered here.
hep-ph/0505206
Eric S. Swanson
F.E. Close and E.S. Swanson
Dynamics and Decay of Heavy-Light Hadrons
19 pages, 7 figures, revtex. A numerical error is corrected. Some strong decay rates have changed
Phys.Rev.D72:094004,2005
10.1103/PhysRevD.72.094004
null
hep-ph
null
Recent signals for narrow hadrons containing heavy and light flavours are compared with quark model predictions for spectroscopy, strong decays, and radiative transitions. In particular, the production and identification of excited charmed and cs states are examined with emphasis on elucidating the nature of $0^+$ and $1^+$ states. Roughly 200 strong decay amplitudes of $D$ and $D_s$ states up to 3.3 GeV are presented. Applications include determining flavour content in $\eta$ mesons and the mixing angle in $P$ and $D$ wave states and probes of putative molecular states. We advocate searching for radially excited $D_s^*$ states in B decays.
[ { "created": "Tue, 24 May 2005 12:05:03 GMT", "version": "v1" }, { "created": "Sat, 8 Oct 2005 01:25:10 GMT", "version": "v2" } ]
2008-11-26
[ [ "Close", "F. E.", "" ], [ "Swanson", "E. S.", "" ] ]
Recent signals for narrow hadrons containing heavy and light flavours are compared with quark model predictions for spectroscopy, strong decays, and radiative transitions. In particular, the production and identification of excited charmed and cs states are examined with emphasis on elucidating the nature of $0^+$ and $1^+$ states. Roughly 200 strong decay amplitudes of $D$ and $D_s$ states up to 3.3 GeV are presented. Applications include determining flavour content in $\eta$ mesons and the mixing angle in $P$ and $D$ wave states and probes of putative molecular states. We advocate searching for radially excited $D_s^*$ states in B decays.