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1205.5648
Dong Phung Van
P. V. Dong, H. T. Hung, H. N. Long
Question of Peccei-Quinn symmetry and quark masses in the economical 3-3-1 model
25 pages, 4 figures, revised version, to appear in Physical Review D
Phys. Rev. D 86, 033002 (2012)
10.1103/PhysRevD.86.033002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that there is an infinite number of U(1) symmetries like Peccei-Quinn symmetry in the 3-3-1 model with minimal scalar sector---two scalar triplets. Moreover, all of them are completely broken due to the model's scalars by themselves (notice that these scalars as known have been often used to break the gauge symmetry and generating the masses for the model's particles). There is no any residual Peccei-Quinn symmetry. Because of the minimal scalar content there are some quarks that are massless at tree-level, but they can get consistent mass contributions at one-loop due to this fact. Interestingly, axions as associated with the mentioned U(1)s breaking (including Majoron due to lepton-charge breaking) are all gauged away because they are also the Goldstone bosons responsible for the gauge symmetry breaking as usual.
[ { "created": "Fri, 25 May 2012 09:36:28 GMT", "version": "v1" }, { "created": "Thu, 12 Jul 2012 11:16:24 GMT", "version": "v2" } ]
2012-08-06
[ [ "Dong", "P. V.", "" ], [ "Hung", "H. T.", "" ], [ "Long", "H. N.", "" ] ]
We show that there is an infinite number of U(1) symmetries like Peccei-Quinn symmetry in the 3-3-1 model with minimal scalar sector---two scalar triplets. Moreover, all of them are completely broken due to the model's scalars by themselves (notice that these scalars as known have been often used to break the gauge symmetry and generating the masses for the model's particles). There is no any residual Peccei-Quinn symmetry. Because of the minimal scalar content there are some quarks that are massless at tree-level, but they can get consistent mass contributions at one-loop due to this fact. Interestingly, axions as associated with the mentioned U(1)s breaking (including Majoron due to lepton-charge breaking) are all gauged away because they are also the Goldstone bosons responsible for the gauge symmetry breaking as usual.
2009.01262
Rishav Roshan
Amit Dutta Banik, Rishav Roshan, Arunansu Sil
Two Component Singlet-Triplet Scalar Dark Matter and Electroweak Vacuum Stability
38 pages, 13 figures, 4 tables (Accepted in PRD)
Phys. Rev. D 103, 075001 (2021)
10.1103/PhysRevD.103.075001
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose a two component dark matter set-up by extending the Standard Model with a singlet and a hypercharge-less triplet scalars, each of them being odd under different $Z_2$ symmetries. We observe that the inter-conversion between the two dark matter components allow a viable parameter space where masses of both the dark matter candidates can be below TeV, even though their individual contribution to single component dark matter rules out any such sub-TeV dark matter. We find that a lighter mass of the neutral component of the scalar triplet, playing the role of one dark matter component, compared to the scalar one is favored. In addition, the set-up is shown to make the electroweak vacuum absolutely stable till the Planck scale, thanks to Higgs portal coupling with the scalar dark matter components.
[ { "created": "Wed, 2 Sep 2020 18:01:04 GMT", "version": "v1" }, { "created": "Thu, 4 Mar 2021 06:25:34 GMT", "version": "v2" } ]
2021-04-07
[ [ "Banik", "Amit Dutta", "" ], [ "Roshan", "Rishav", "" ], [ "Sil", "Arunansu", "" ] ]
We propose a two component dark matter set-up by extending the Standard Model with a singlet and a hypercharge-less triplet scalars, each of them being odd under different $Z_2$ symmetries. We observe that the inter-conversion between the two dark matter components allow a viable parameter space where masses of both the dark matter candidates can be below TeV, even though their individual contribution to single component dark matter rules out any such sub-TeV dark matter. We find that a lighter mass of the neutral component of the scalar triplet, playing the role of one dark matter component, compared to the scalar one is favored. In addition, the set-up is shown to make the electroweak vacuum absolutely stable till the Planck scale, thanks to Higgs portal coupling with the scalar dark matter components.
hep-ph/0506129
Martin Lemoine
Karsten Jedamzik (LPTA), Martin Lemoine (IAP), Gilbert Moultaka (LPTA)
Gravitino dark matter in gauge mediated supersymmetry breaking
21 pages, 5 figures ; matches published version
Phys.Rev. D73 (2006) 043514
10.1103/PhysRevD.73.043514
null
hep-ph astro-ph hep-th
null
This paper investigates the parameter space of theories with gauge mediated supersymmetry breaking leading to gravitino (cold) dark matter with mass m_{3/2}= 1keV - 10MeV. We pay particular attention to the cosmological role of messenger fields. Cosmology requires that these messengers decay to the visible sector if the lightest messenger mass M_X > 30TeV. We then examine the various possible messenger number violating interactions allowed by the symmetries of the theory and by phenomenology. Late messenger decay generally results in entropy production hence in the dilution of pre-existing gravitinos. We find that in SU(5) grand unification only specific messenger-matter couplings allow to produce the required amount of gravitino dark matter particles. Gravitino dark matter with the correct abundance is however expected in larger gauge groups such as SO(10) for generic non-renormalizable messenger-matter interactions and for arbritrarily high post-inflationary reheating temperatures.
[ { "created": "Tue, 14 Jun 2005 07:42:46 GMT", "version": "v1" }, { "created": "Tue, 9 May 2006 14:44:55 GMT", "version": "v2" } ]
2009-11-11
[ [ "Jedamzik", "Karsten", "", "LPTA" ], [ "Lemoine", "Martin", "", "IAP" ], [ "Moultaka", "Gilbert", "", "LPTA" ] ]
This paper investigates the parameter space of theories with gauge mediated supersymmetry breaking leading to gravitino (cold) dark matter with mass m_{3/2}= 1keV - 10MeV. We pay particular attention to the cosmological role of messenger fields. Cosmology requires that these messengers decay to the visible sector if the lightest messenger mass M_X > 30TeV. We then examine the various possible messenger number violating interactions allowed by the symmetries of the theory and by phenomenology. Late messenger decay generally results in entropy production hence in the dilution of pre-existing gravitinos. We find that in SU(5) grand unification only specific messenger-matter couplings allow to produce the required amount of gravitino dark matter particles. Gravitino dark matter with the correct abundance is however expected in larger gauge groups such as SO(10) for generic non-renormalizable messenger-matter interactions and for arbritrarily high post-inflationary reheating temperatures.
hep-ph/9606255
null
B.Kerbikov, S.V.Bashinsky
$K\bar{K}$ Threshold Phenomena, $f_0-a_0$ Interference and Kaonium Production
2 pages; to appear in the proceedings of the XIV Int. Conf. on Particle and Nuclei, Williamsburg, May 22-28, 1996
null
null
null
hep-ph
null
We develop a new formalism to study $K\bar{K}$ threshold phenomena with resonances $f_0$, $a_0$ and $K^+K^-$ atom (kaonium) included. The approach provides two possible scenarios for $f_0-a_0$ mixing. Drastic interference patterns can be observed in $K^+K^-$electroproduction at CEBAF, $pd\to ~^3HeX$ reaction, and $N\bar N$ annihilation.
[ { "created": "Thu, 6 Jun 1996 14:28:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kerbikov", "B.", "" ], [ "Bashinsky", "S. V.", "" ] ]
We develop a new formalism to study $K\bar{K}$ threshold phenomena with resonances $f_0$, $a_0$ and $K^+K^-$ atom (kaonium) included. The approach provides two possible scenarios for $f_0-a_0$ mixing. Drastic interference patterns can be observed in $K^+K^-$electroproduction at CEBAF, $pd\to ~^3HeX$ reaction, and $N\bar N$ annihilation.
1505.04191
Sebastian Ellis
Sebastian A. R. Ellis and Gordon L. Kane
Lepton Flavour Violation via the K\"ahler Potential in Compactified M-Theory
32 pages, 7 figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use lepton-flavour violating (LFV) processes as a probe of higher-order corrections to the K\"ahler potential in compactified M-theory. We consider a generic K\"ahler potential with higher-order terms coupling visible sector fields to fields in the hidden sector of the compactified theory. Such terms generally give rise to potentially large flavour-violating effects. Unless there are suppressions, the size of the resulting off-diagonal terms in the K\"ahler potential may be at odds with experimental results. The rare decay $\mu \to e \gamma$ and $\mu \to e$ conversion in nuclei probe the size of the potential flavour non-diagonality of the higher-order terms for realistic spectra in the M-theory compactification. We consider a parameterisation of the higher-order corrections in terms of a small parameter $\epsilon$. By analysing various textures for the higher-order corrections, we find current bounds on $\epsilon$ from the LFV processes. The constraint from the neutral kaon mass difference $\Delta m_K$ is currently similar to that from $\mu \to e \gamma$. Measurement or new limits on the process $\mu \to e \gamma$ and, in the future, $\mu \to e$ conversion in Aluminium, will be an effective probe of the form of the higher-order K\"ahler potential terms. For the preferred range of gravitino masses, unless the K\"ahler potential is strikingly flavour-diagonal, improvement in experimental sensitivity of LFV processes should give a non-zero signal.
[ { "created": "Fri, 15 May 2015 20:00:30 GMT", "version": "v1" } ]
2015-05-19
[ [ "Ellis", "Sebastian A. R.", "" ], [ "Kane", "Gordon L.", "" ] ]
We use lepton-flavour violating (LFV) processes as a probe of higher-order corrections to the K\"ahler potential in compactified M-theory. We consider a generic K\"ahler potential with higher-order terms coupling visible sector fields to fields in the hidden sector of the compactified theory. Such terms generally give rise to potentially large flavour-violating effects. Unless there are suppressions, the size of the resulting off-diagonal terms in the K\"ahler potential may be at odds with experimental results. The rare decay $\mu \to e \gamma$ and $\mu \to e$ conversion in nuclei probe the size of the potential flavour non-diagonality of the higher-order terms for realistic spectra in the M-theory compactification. We consider a parameterisation of the higher-order corrections in terms of a small parameter $\epsilon$. By analysing various textures for the higher-order corrections, we find current bounds on $\epsilon$ from the LFV processes. The constraint from the neutral kaon mass difference $\Delta m_K$ is currently similar to that from $\mu \to e \gamma$. Measurement or new limits on the process $\mu \to e \gamma$ and, in the future, $\mu \to e$ conversion in Aluminium, will be an effective probe of the form of the higher-order K\"ahler potential terms. For the preferred range of gravitino masses, unless the K\"ahler potential is strikingly flavour-diagonal, improvement in experimental sensitivity of LFV processes should give a non-zero signal.
hep-ph/0212104
Alexei Nefediev
A.V.Nefediev (IST, Lisbon and ITEP, Moscow), J.E.F.T.Ribeiro (IST, Lisbon)
Quantum field theory approach to the vacuum replica in QCD
LaTeX2e, 2 EPS figures, uses ws-procs9x6 (included) and epsfig classes, Talk given at the conference "Quark Confinement and the Hadron Spectrum V", 10-14 September 2002, Gargnano, Italy, to appear in Proceedings
null
10.1142/9789812704269_0067
null
hep-ph
null
Quantum field theory is used to describe the contribution of possible new QCD vacuum replica to hadronic processes. This sigma-like new state has been recently shown to be likely to appear for any realistic four-quark interaction kernel as a consequence of chiral symmetry. The local operator creating the replica vacuum state is constructed explicitly. Applications to physical processes are outlined.
[ { "created": "Fri, 6 Dec 2002 17:15:13 GMT", "version": "v1" } ]
2017-08-23
[ [ "Nefediev", "A. V.", "", "IST, Lisbon and ITEP, Moscow" ], [ "Ribeiro", "J. E. F. T.", "", "IST,\n Lisbon" ] ]
Quantum field theory is used to describe the contribution of possible new QCD vacuum replica to hadronic processes. This sigma-like new state has been recently shown to be likely to appear for any realistic four-quark interaction kernel as a consequence of chiral symmetry. The local operator creating the replica vacuum state is constructed explicitly. Applications to physical processes are outlined.
hep-ph/9912390
James Wells
Riccardo Rattazzi, Alessandro Strumia, James D. Wells
Phenomenology of deflected anomaly-mediation
18 pages, latex, refs added
Nucl.Phys.B576:3-28,2000
10.1016/S0550-3213(00)00130-9
IFUP-TH/54-99 and SNS-PH/99-16 and UCD-99-25
hep-ph
null
We explore the phenomenology of a class of models with anomaly-mediated supersymmetry breaking. These models retain the successful flavor properties of the minimal scenario while avoiding the tachyons. The mass spectrum is predicted in terms of a few parameters. However various qualitatively different spectra are possible, often strongly different from the ones usually employed to explore capabilities of new accelerators. One stable feature is the limited spread of the spectrum, so that squarks and gluinos could be conceivably produced at TEVII. The lightest superpartner of standard particles is often a charged slepton or a neutral higgsino. It behaves as a stable particle in collider experiments but it decays at or before nucleosynthesis. We identify the experimental signatures at hadron colliders that can help distinguish this scenario from the usual ones.
[ { "created": "Fri, 17 Dec 1999 18:00:41 GMT", "version": "v1" }, { "created": "Thu, 23 Dec 1999 00:02:16 GMT", "version": "v2" } ]
2008-11-26
[ [ "Rattazzi", "Riccardo", "" ], [ "Strumia", "Alessandro", "" ], [ "Wells", "James D.", "" ] ]
We explore the phenomenology of a class of models with anomaly-mediated supersymmetry breaking. These models retain the successful flavor properties of the minimal scenario while avoiding the tachyons. The mass spectrum is predicted in terms of a few parameters. However various qualitatively different spectra are possible, often strongly different from the ones usually employed to explore capabilities of new accelerators. One stable feature is the limited spread of the spectrum, so that squarks and gluinos could be conceivably produced at TEVII. The lightest superpartner of standard particles is often a charged slepton or a neutral higgsino. It behaves as a stable particle in collider experiments but it decays at or before nucleosynthesis. We identify the experimental signatures at hadron colliders that can help distinguish this scenario from the usual ones.
1804.10378
Yong Tang
Takeo Moroi, Kazunori Nakayama and Yong Tang
Axion-Photon Conversion and Effects on 21cm Observation
1+12 pages, 3 figures
null
10.1016/j.physletb.2018.07.002
UT-18-09
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently the EDGES experiment reported an enhanced 21cm absorption signal in the radio wave observation, which may be interpreted as either anomalous cooling of baryons or heating of cosmic microwave background photons. In this paper, we pursue the latter possibility. We point out that dark radiation consisting of axion-like particles can resonantly convert into photons under the intergalactic magnetic field, which can effectively heat up the radiation in the frequency range relevant for the EDGES experiment. This may explain the EDGES anomaly.
[ { "created": "Fri, 27 Apr 2018 08:13:36 GMT", "version": "v1" }, { "created": "Sun, 8 Jul 2018 01:27:16 GMT", "version": "v2" } ]
2018-07-10
[ [ "Moroi", "Takeo", "" ], [ "Nakayama", "Kazunori", "" ], [ "Tang", "Yong", "" ] ]
Recently the EDGES experiment reported an enhanced 21cm absorption signal in the radio wave observation, which may be interpreted as either anomalous cooling of baryons or heating of cosmic microwave background photons. In this paper, we pursue the latter possibility. We point out that dark radiation consisting of axion-like particles can resonantly convert into photons under the intergalactic magnetic field, which can effectively heat up the radiation in the frequency range relevant for the EDGES experiment. This may explain the EDGES anomaly.
hep-ph/9904201
null
Tatsuo Kobayashi, Jisuke Kubo, Hitoshi Shimabukuro
Electroweak symmetry breaking and s-spectrum in M-theory
34 pages, 24 figures
Nucl.Phys. B580 (2000) 3-28
10.1016/S0550-3213(00)00138-3
HIP-1999-14/TH and KANAZAWA-99-05
hep-ph hep-th
null
We study soft SUSY breaking parameters in M-theory with and without 5-brane moduli fields. We investigate successful electroweak symmetry breaking and the positivity of stau mass squared. We study mass spectra in allowed regions.
[ { "created": "Thu, 1 Apr 1999 04:52:08 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kobayashi", "Tatsuo", "" ], [ "Kubo", "Jisuke", "" ], [ "Shimabukuro", "Hitoshi", "" ] ]
We study soft SUSY breaking parameters in M-theory with and without 5-brane moduli fields. We investigate successful electroweak symmetry breaking and the positivity of stau mass squared. We study mass spectra in allowed regions.
0811.2901
Kirill Semenov-Tian-Shansky
Maxim V. Polyakov and Kirill M. Semenov-Tian-Shansky
Dual parametrization of GPDs versus the double distribution Ansatz
18 pages, 5 figures. A version that appeared in Eur. Phys. J. A. Some of the statements were refined and misprints in the formulas were corrected
Eur.Phys.J.A40:181-198,2009
10.1140/epja/i2008-10759-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish a link between the dual parametrization of GPDs and a popular parametrization based on the double distribution Ansatz, which is in prevalent use in phenomenological applications. We compute several first forward-like functions that express the double distribution Ansatz for GPDs in the framework of the dual parametrization and show that these forward-like functions make the dominant contribution into the GPD quintessence function. We also argue that the forward-like functions $Q_{2 \nu}(x)$ with $\nu \ge 1$ contribute to the leading singular small-$x_{Bj}$ behavior of the imaginary part of DVCS amplitude. This makes the small-$x_{Bj}$ behavior of $\im A^{DVCS}$ independent of the asymptotic behavior of PDFs. Assuming analyticity of Mellin moments of GPDs in the Mellin space we are able to fix the value of the $D$-form factor in terms of the GPD quintessence function $N(x,t)$ and the forward-like function $Q_0(x,t)$.
[ { "created": "Tue, 18 Nov 2008 13:53:41 GMT", "version": "v1" }, { "created": "Sun, 31 May 2009 09:29:31 GMT", "version": "v2" } ]
2011-04-12
[ [ "Polyakov", "Maxim V.", "" ], [ "Semenov-Tian-Shansky", "Kirill M.", "" ] ]
We establish a link between the dual parametrization of GPDs and a popular parametrization based on the double distribution Ansatz, which is in prevalent use in phenomenological applications. We compute several first forward-like functions that express the double distribution Ansatz for GPDs in the framework of the dual parametrization and show that these forward-like functions make the dominant contribution into the GPD quintessence function. We also argue that the forward-like functions $Q_{2 \nu}(x)$ with $\nu \ge 1$ contribute to the leading singular small-$x_{Bj}$ behavior of the imaginary part of DVCS amplitude. This makes the small-$x_{Bj}$ behavior of $\im A^{DVCS}$ independent of the asymptotic behavior of PDFs. Assuming analyticity of Mellin moments of GPDs in the Mellin space we are able to fix the value of the $D$-form factor in terms of the GPD quintessence function $N(x,t)$ and the forward-like function $Q_0(x,t)$.
hep-ph/0107320
Yangmz
Dong-Sheng Du, Chao-Shang Huang, Zheng-Tao Wei, Mao-Zhi Yang
Sudakov effects in BBNS approach
16 pages, Latex, two figures, some typos corrected
Phys.Lett. B520 (2001) 50-58; Erratum-ibid. B530 (2002) 258
10.1016/S0370-2693(01)01118-2
null
hep-ph
null
The end-point singularity is an unsolved problem in BBNS approach. Incorporating the partonic transverse momentum and the Sudakov form factor, this problem can be solved model-independently. We discuss the Sudakov effects in BBNS approach. The BBNS approach is compared with the modified PQCD approach. The main idea of Sudakov form factor is briefly discussed. Our conclusion is that the twist-3 contribution for the hard spectator scattering is numerically not important in $B\to \pi\pi$ decays, compared with the twist-2 contribution.
[ { "created": "Tue, 31 Jul 2001 12:06:20 GMT", "version": "v1" }, { "created": "Mon, 4 Feb 2002 04:16:08 GMT", "version": "v2" } ]
2009-11-07
[ [ "Du", "Dong-Sheng", "" ], [ "Huang", "Chao-Shang", "" ], [ "Wei", "Zheng-Tao", "" ], [ "Yang", "Mao-Zhi", "" ] ]
The end-point singularity is an unsolved problem in BBNS approach. Incorporating the partonic transverse momentum and the Sudakov form factor, this problem can be solved model-independently. We discuss the Sudakov effects in BBNS approach. The BBNS approach is compared with the modified PQCD approach. The main idea of Sudakov form factor is briefly discussed. Our conclusion is that the twist-3 contribution for the hard spectator scattering is numerically not important in $B\to \pi\pi$ decays, compared with the twist-2 contribution.
1407.8544
Thomas W. Kephart
Paul H. Frampton and Thomas W. Kephart
Sum Rule Constraint on Models Beyond the Standard Model
11 pages, 1 figure; minor edits in version 2
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In most versions of beyond the standard model (BSM) physics, the Yukawa couplings of the quarks and charged leptons are not all to the same complex scalar doublet but to different ones. Comparison to the standard model (SM) with only one scalar doublet, using the known mass of the W boson, provides a sum rule constraint on the Yukawa couplings $Y_i,~~ i=t, b, \tau,.....$ of the form $\Sigma_i r_i^2 = 1$ where $r_i = Y_i^{(SM)}/Y_i^{(BSM)}$ and the sum is over distinct scalar doublets. The LHC data on the branching ratios $H \rightarrow \gamma\gamma, ~\bar{b}b, ~\tau^+\tau^-, ~etc.,$ allows detailed comparison to this sum rule constraint and, as accuracy improves, will constrain or exclude many BSM theories.
[ { "created": "Thu, 31 Jul 2014 19:47:04 GMT", "version": "v1" }, { "created": "Thu, 13 Aug 2015 15:44:00 GMT", "version": "v2" } ]
2015-08-14
[ [ "Frampton", "Paul H.", "" ], [ "Kephart", "Thomas W.", "" ] ]
In most versions of beyond the standard model (BSM) physics, the Yukawa couplings of the quarks and charged leptons are not all to the same complex scalar doublet but to different ones. Comparison to the standard model (SM) with only one scalar doublet, using the known mass of the W boson, provides a sum rule constraint on the Yukawa couplings $Y_i,~~ i=t, b, \tau,.....$ of the form $\Sigma_i r_i^2 = 1$ where $r_i = Y_i^{(SM)}/Y_i^{(BSM)}$ and the sum is over distinct scalar doublets. The LHC data on the branching ratios $H \rightarrow \gamma\gamma, ~\bar{b}b, ~\tau^+\tau^-, ~etc.,$ allows detailed comparison to this sum rule constraint and, as accuracy improves, will constrain or exclude many BSM theories.
1703.08329
Takumi Kuwahara
Junji Hisano, Takumi Kuwahara, Yuji Omura, and Takeki Sato
Two-loop Anomalous Dimensions for Four-Fermi Operators in Supersymmetric Theories
20 pages, Version accepted for publication in Nuclear Physics B
Nuclear Physics B 922C (2017) pp. 77-93
10.1016/j.nuclphysb.2017.06.021
IPMU17-0043
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive two-loop anomalous dimensions for four-Fermi operators in supersymmetric theories using the effective Kahler potential. We introduce the general forms in generic gauge theories and apply our results to the flavor-changing operators in (minimal) supersymmetric standard models.
[ { "created": "Fri, 24 Mar 2017 09:45:14 GMT", "version": "v1" }, { "created": "Wed, 12 Jul 2017 08:46:01 GMT", "version": "v2" } ]
2017-07-13
[ [ "Hisano", "Junji", "" ], [ "Kuwahara", "Takumi", "" ], [ "Omura", "Yuji", "" ], [ "Sato", "Takeki", "" ] ]
We derive two-loop anomalous dimensions for four-Fermi operators in supersymmetric theories using the effective Kahler potential. We introduce the general forms in generic gauge theories and apply our results to the flavor-changing operators in (minimal) supersymmetric standard models.
hep-ph/0404051
Takashi Inoue
T. Inoue, V. E. Lyubovitskij, Th. Gutsche and Amand Faessler
Ground-state baryon masses in the perturbative chiral quark model
24 pages, 3 figures
Int.J.Mod.Phys. E15 (2006) 121-142
10.1142/S0218301306003862
null
hep-ph nucl-th
null
Mass differences of the flavor octet and decuplet ground-state baryons are studied in the perturbative chiral quark model. We present a way to understand the nontrivial spin- and flavor dependent mass differences, where both pseudoscalar mesons and gluons play a significant role.
[ { "created": "Tue, 6 Apr 2004 09:36:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Inoue", "T.", "" ], [ "Lyubovitskij", "V. E.", "" ], [ "Gutsche", "Th.", "" ], [ "Faessler", "Amand", "" ] ]
Mass differences of the flavor octet and decuplet ground-state baryons are studied in the perturbative chiral quark model. We present a way to understand the nontrivial spin- and flavor dependent mass differences, where both pseudoscalar mesons and gluons play a significant role.
0901.1106
Pierre Sikivie
P. Sikivie and Q. Yang
Bose-Einstein Condensation of Dark Matter Axions
4 pages. Three typos are corrected. Version to be published by Physical Review Letters
Phys.Rev.Lett.103:111301,2009
10.1103/PhysRevLett.103.111301
UFIFT-HEP-09-1
hep-ph astro-ph.CO cond-mat.stat-mech
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.
[ { "created": "Thu, 8 Jan 2009 18:44:45 GMT", "version": "v1" }, { "created": "Mon, 19 Jan 2009 17:04:50 GMT", "version": "v2" }, { "created": "Wed, 29 Jul 2009 21:05:54 GMT", "version": "v3" }, { "created": "Wed, 2 Sep 2009 20:15:05 GMT", "version": "v4" } ]
2009-11-06
[ [ "Sikivie", "P.", "" ], [ "Yang", "Q.", "" ] ]
We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.
hep-ph/0606246
Danny Marfatia
S. Hussain, D. Marfatia, D. W. McKay, D. Seckel
Cross section dependence of event rates at neutrino telescopes
4 pages, 2 figures. Version to appear in PRL
Phys.Rev.Lett. 97 (2006) 161101
10.1103/PhysRevLett.97.161101
null
hep-ph astro-ph hep-ex
null
We examine the dependence of event rates at neutrino telescopes on the neutrino-nucleon cross section for neutrinos with energy above 1 PeV, and contrast the results with those for cosmic ray experiments. Simple scaling of the Standard Model cross sections leaves the rates of upward events essentially unchanged. Details, such as detector depth and cross section inelasticity, can influence rates. Numerical estimates of upward shower, muon and tau event rates in the IceCube detector confirm these results.
[ { "created": "Thu, 22 Jun 2006 20:00:05 GMT", "version": "v1" }, { "created": "Thu, 14 Sep 2006 03:46:56 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hussain", "S.", "" ], [ "Marfatia", "D.", "" ], [ "McKay", "D. W.", "" ], [ "Seckel", "D.", "" ] ]
We examine the dependence of event rates at neutrino telescopes on the neutrino-nucleon cross section for neutrinos with energy above 1 PeV, and contrast the results with those for cosmic ray experiments. Simple scaling of the Standard Model cross sections leaves the rates of upward events essentially unchanged. Details, such as detector depth and cross section inelasticity, can influence rates. Numerical estimates of upward shower, muon and tau event rates in the IceCube detector confirm these results.
1307.6840
Gilberto Ramalho
G. Ramalho and K. Tsushima
What is the role of the meson cloud in the $\Sigma^{*0} \to \gamma \Lambda$ and $\Sigma^\ast \to \gamma \Sigma$ decays?
Published in Phys.Rev.D. 14 pages, 1 figure, 6 tables. Minor corrections
Phys. Rev. D 88, 053002 (2013)
10.1103/PhysRevD.88.053002
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effect of the meson cloud dressing in the octet baryon to decuplet baryon electromagnetic transitions. Combining the valence quark contributions from the covariant spectator quark model with those of the meson cloud estimated based on the flavor SU(3) cloudy bag model, we calculate the transition magnetic form factors at $Q^2=0$ ($Q^2=-q^2$ and $q$ the four-momentum transfer), and also the decuplet baryon electromagnetic decay widths. The result for the $\gamma^\ast \Lambda \to \Sigma^{\ast 0}$ decay width is in complete agreement with the data, while that for the $\gamma^\ast \Sigma^+ \to \Sigma^{\ast +}$ is underestimated the data by 1.4 standard deviations. This achievement may be regarded as a significant advance in the present theoretical situation.
[ { "created": "Thu, 25 Jul 2013 18:53:57 GMT", "version": "v1" }, { "created": "Tue, 3 Sep 2013 16:02:15 GMT", "version": "v2" } ]
2013-09-09
[ [ "Ramalho", "G.", "" ], [ "Tsushima", "K.", "" ] ]
We study the effect of the meson cloud dressing in the octet baryon to decuplet baryon electromagnetic transitions. Combining the valence quark contributions from the covariant spectator quark model with those of the meson cloud estimated based on the flavor SU(3) cloudy bag model, we calculate the transition magnetic form factors at $Q^2=0$ ($Q^2=-q^2$ and $q$ the four-momentum transfer), and also the decuplet baryon electromagnetic decay widths. The result for the $\gamma^\ast \Lambda \to \Sigma^{\ast 0}$ decay width is in complete agreement with the data, while that for the $\gamma^\ast \Sigma^+ \to \Sigma^{\ast +}$ is underestimated the data by 1.4 standard deviations. This achievement may be regarded as a significant advance in the present theoretical situation.
1302.1496
Frans Klinkhamer
F.R. Klinkhamer
Standard Model Higgs field and energy scale of gravity
v5: published version
JETP Letters 97, 297 (2013)
10.1134/S002136401306009X
KA-TP-03-2013
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effective potential of the Higgs scalar field in the Standard Model may have a second degenerate minimum at an ultrahigh vacuum expectation value. This second minimum then determines, by radiative corrections, the values of the top-quark and Higgs-boson masses at the standard minimum corresponding to the electroweak energy scale. An argument is presented that this ultrahigh vacuum expectation value is proportional to the energy scale of gravity, E_{Planck} \equiv \sqrt{\hbar c^5/G_N}, considered to be characteristic of a spacetime foam. In the context of a simple model, the existence of kink-type wormhole solutions places a lower bound on the ultrahigh vacuum expectation value and this lower bound is of the order of E_{Planck}.
[ { "created": "Wed, 6 Feb 2013 20:10:44 GMT", "version": "v1" }, { "created": "Mon, 11 Feb 2013 19:58:37 GMT", "version": "v2" }, { "created": "Thu, 14 Feb 2013 20:11:24 GMT", "version": "v3" }, { "created": "Tue, 26 Feb 2013 16:30:01 GMT", "version": "v4" }, { "created": "Thu, 25 Apr 2013 14:26:51 GMT", "version": "v5" } ]
2015-06-12
[ [ "Klinkhamer", "F. R.", "" ] ]
The effective potential of the Higgs scalar field in the Standard Model may have a second degenerate minimum at an ultrahigh vacuum expectation value. This second minimum then determines, by radiative corrections, the values of the top-quark and Higgs-boson masses at the standard minimum corresponding to the electroweak energy scale. An argument is presented that this ultrahigh vacuum expectation value is proportional to the energy scale of gravity, E_{Planck} \equiv \sqrt{\hbar c^5/G_N}, considered to be characteristic of a spacetime foam. In the context of a simple model, the existence of kink-type wormhole solutions places a lower bound on the ultrahigh vacuum expectation value and this lower bound is of the order of E_{Planck}.
1511.06371
Vedran Brdar
Vedran Brdar, Matthias K\"onig, Joachim Kopp (Johannes Gutenberg University Mainz)
Neutrino Anarchy and Renormalization Group Evolution
23 pages, 12 figures. v2: References added, matches version to be published in PRD
Phys. Rev. D 93, 093010 (2016)
10.1103/PhysRevD.93.093010
MITP/15-104
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observed pattern of neutrino mixing angles is in good agreement with the hypothesis of neutrino anarchy, which posits that Nature has chosen the entries of the leptonic mixing matrix at random. In this paper we investigate how stable this conclusion is under renormalization group effects. Working in the simplest type-I seesaw model and two variants of the inverse seesaw model we study how the statistical distributions of the neutrino mixing parameters evolve between the Grand Unification scale and the electroweak scale. Especially in the inverse seesaw case we find significant distortions: mixing angles tend to be smaller after RG running, and the Dirac CP phase tends to be closer to zero. The p-value describing the compatibility between the observed mixing angles and the anarchy hypothesis increases by 10-20%. This illustrates that RG effects are highly relevant for quantitative studies of the anarchy scenario.
[ { "created": "Thu, 19 Nov 2015 21:00:02 GMT", "version": "v1" }, { "created": "Wed, 25 May 2016 22:44:47 GMT", "version": "v2" } ]
2016-05-27
[ [ "Brdar", "Vedran", "", "Johannes Gutenberg\n University Mainz" ], [ "König", "Matthias", "", "Johannes Gutenberg\n University Mainz" ], [ "Kopp", "Joachim", "", "Johannes Gutenberg\n University Mainz" ] ]
The observed pattern of neutrino mixing angles is in good agreement with the hypothesis of neutrino anarchy, which posits that Nature has chosen the entries of the leptonic mixing matrix at random. In this paper we investigate how stable this conclusion is under renormalization group effects. Working in the simplest type-I seesaw model and two variants of the inverse seesaw model we study how the statistical distributions of the neutrino mixing parameters evolve between the Grand Unification scale and the electroweak scale. Especially in the inverse seesaw case we find significant distortions: mixing angles tend to be smaller after RG running, and the Dirac CP phase tends to be closer to zero. The p-value describing the compatibility between the observed mixing angles and the anarchy hypothesis increases by 10-20%. This illustrates that RG effects are highly relevant for quantitative studies of the anarchy scenario.
2009.01781
Renan Pereira
Pedro Costa, Renan C\^amara Pereira, Constan\c{c}a Provid\^encia
Role of the conserved charges in the chiral symmetry restoration phase transition
8 pages, 4 figures
Phys. Rev. D 102, 054010 (2020)
10.1103/PhysRevD.102.054010
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effect of conserved baryon, isospin and strangeness charges on the behavior of phase transitions in dense matter is studied. Baryonic matter is described within the three-flavor Polyakov$-$Nambu$-$Jona-Lasinio model and several charge fractions $Y_Q$ are considered. The role of the vector interaction, which can be important to describe dense systems, is discussed. Special attention is given to the case with charge fraction $Y_Q=0.4$, due to its importance in heavy-ion collisions and core-collapse supernova matter. It is shown that the possible formation of chiral-symmetric quark matter in the laboratory will be favored in asymmetric matter. Besides, the inclusion of the vector interaction reinforces the formation of quark matter at lower densities.
[ { "created": "Thu, 3 Sep 2020 16:39:43 GMT", "version": "v1" } ]
2020-09-14
[ [ "Costa", "Pedro", "" ], [ "Pereira", "Renan Câmara", "" ], [ "Providência", "Constança", "" ] ]
The effect of conserved baryon, isospin and strangeness charges on the behavior of phase transitions in dense matter is studied. Baryonic matter is described within the three-flavor Polyakov$-$Nambu$-$Jona-Lasinio model and several charge fractions $Y_Q$ are considered. The role of the vector interaction, which can be important to describe dense systems, is discussed. Special attention is given to the case with charge fraction $Y_Q=0.4$, due to its importance in heavy-ion collisions and core-collapse supernova matter. It is shown that the possible formation of chiral-symmetric quark matter in the laboratory will be favored in asymmetric matter. Besides, the inclusion of the vector interaction reinforces the formation of quark matter at lower densities.
0907.0205
Florian Hahn-Woernle
F. Hahn-Woernle, M. Plumacher, Y.Y.Y. Wong
Full Boltzmann equations for leptogenesis including scattering
39 pages, 8 figures, typos corrected, replaced to match published version
JCAP 0908:028,2009
10.1088/1475-7516/2009/08/028
CERN-PH-TH/2009-107, MPP-2009-85, PITHA 09/15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evolution of a cosmological baryon asymmetry produced via leptogenesis by means of the full classical Boltzmann equations, without the assumption of kinetic equilibrium and including all quantum statistical factors. Beginning with the full mode equations we derive the usual equations of motion for the right-handed neutrino number density and integrated lepton asymmetry, and show explicitly the impact of each assumption on these quantities. For the first time, we investigate also the effects of scattering of the right-handed neutrino with the top quark to leading order in the Yukawa couplings by means of the full Boltzmann equations. We find that in our full Boltzmann treatment the final lepton asymmetry can be suppressed by as much as a factor of 1.5 in the weak wash-out regime (K<1), compared to the usual integrated approach which assumes kinetic equilibrium and neglects quantum statistics. This suppression is in contrast with the enhancement seen in some previous studies that considered only decay and inverse decay of the right-handed neutrino. However, this suppression quickly decreases as we increase K. In the strong wash-out regime (K>1), the full Boltzmann treatment and the integrated approach give nearly identical final lepton asymmetries (within 10 % of each other at K>3). Finally, we show that the opposing effects of quantum statistics on decays/inverse decays and the scattering processes tend to reduce the net importance of scattering on leptogenesis in the full treatment compared to the integrated approach.
[ { "created": "Wed, 1 Jul 2009 18:00:13 GMT", "version": "v1" }, { "created": "Tue, 25 Aug 2009 18:36:53 GMT", "version": "v2" } ]
2009-09-28
[ [ "Hahn-Woernle", "F.", "" ], [ "Plumacher", "M.", "" ], [ "Wong", "Y. Y. Y.", "" ] ]
We study the evolution of a cosmological baryon asymmetry produced via leptogenesis by means of the full classical Boltzmann equations, without the assumption of kinetic equilibrium and including all quantum statistical factors. Beginning with the full mode equations we derive the usual equations of motion for the right-handed neutrino number density and integrated lepton asymmetry, and show explicitly the impact of each assumption on these quantities. For the first time, we investigate also the effects of scattering of the right-handed neutrino with the top quark to leading order in the Yukawa couplings by means of the full Boltzmann equations. We find that in our full Boltzmann treatment the final lepton asymmetry can be suppressed by as much as a factor of 1.5 in the weak wash-out regime (K<1), compared to the usual integrated approach which assumes kinetic equilibrium and neglects quantum statistics. This suppression is in contrast with the enhancement seen in some previous studies that considered only decay and inverse decay of the right-handed neutrino. However, this suppression quickly decreases as we increase K. In the strong wash-out regime (K>1), the full Boltzmann treatment and the integrated approach give nearly identical final lepton asymmetries (within 10 % of each other at K>3). Finally, we show that the opposing effects of quantum statistics on decays/inverse decays and the scattering processes tend to reduce the net importance of scattering on leptogenesis in the full treatment compared to the integrated approach.
hep-ph/0511243
Roberto Pittau
R. Pittau (U. of Torino), F. del Aguila (U. of Granada) and Ll. Ametller (U. Politecnica de Catalunya)
QCD corrections to forward-backward charge asymmetries in l- l+ j production at hadron colliders
5 pages, 1 figure, talk presentad by R. Pittau at the International Europhysics Conference on High Energy Physics, July 21st - 27th 2005, Lisbon, Portugal
null
null
null
hep-ph
null
The large cross sections for gauge boson production at the Fermilab Tevatron and the CERN Large Hadron Collider (LHC) might give a chance to determine the electroweak parameters with high precision. We calculated two different forward-backward charge asymmetries (A^CS_FB and A^j_FB) of lepton pairs in events with a large transverse momentum jet p p (pbar) -> Z, gamma* + j -> e- e+ j at next-to-leading order (NLO), O(alpha_s) corrections, making use of the Monte Carlo programs MCFM and ALPGEN. These observables could provide a new determination of the weak mixing angle sin^2 theta^lept_eff (M_Z^2) with a statistical precision for each lepton flavour of 10^{-3} (7 x 10^{-3}) at LHC (Tevatron). If b jets are identified, a new asymmetry with respect to the b quark (A^b_FB) can also be measured with a statistical precision of 2 x 10^{-3} (4 x 10^{-2}) at LHC (Tevatron). Finally, we comment on the dependence of our results on various sources of uncertainties and compare, in the case of A^b_FB, the exact result with an approximation that might be more suitable when performing a realistic experimental analysis.
[ { "created": "Mon, 21 Nov 2005 16:56:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pittau", "R.", "", "U. of Torino" ], [ "del Aguila", "F.", "", "U. of Granada" ], [ "Ametller", "Ll.", "", "U. Politecnica de Catalunya" ] ]
The large cross sections for gauge boson production at the Fermilab Tevatron and the CERN Large Hadron Collider (LHC) might give a chance to determine the electroweak parameters with high precision. We calculated two different forward-backward charge asymmetries (A^CS_FB and A^j_FB) of lepton pairs in events with a large transverse momentum jet p p (pbar) -> Z, gamma* + j -> e- e+ j at next-to-leading order (NLO), O(alpha_s) corrections, making use of the Monte Carlo programs MCFM and ALPGEN. These observables could provide a new determination of the weak mixing angle sin^2 theta^lept_eff (M_Z^2) with a statistical precision for each lepton flavour of 10^{-3} (7 x 10^{-3}) at LHC (Tevatron). If b jets are identified, a new asymmetry with respect to the b quark (A^b_FB) can also be measured with a statistical precision of 2 x 10^{-3} (4 x 10^{-2}) at LHC (Tevatron). Finally, we comment on the dependence of our results on various sources of uncertainties and compare, in the case of A^b_FB, the exact result with an approximation that might be more suitable when performing a realistic experimental analysis.
hep-ph/0611003
Heather E. Logan
Heather E. Logan (Carleton U.)
QCD corrections to neutralino annihilation
4 pages, to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 2006
AIPConf.Proc.903:571-574,2007
10.1063/1.2735249
null
hep-ph
null
We report on two recent calculations of QCD corrections to neutralino annihilation cross sections: (1) the next-to-leading order corrections to chi chi -> g g, and (2) the contribution to the cross section for chi chi -> q qbar g arising from interference between the tree-level and loop-induced processes.
[ { "created": "Wed, 1 Nov 2006 01:34:38 GMT", "version": "v1" } ]
2008-11-26
[ [ "Logan", "Heather E.", "", "Carleton U." ] ]
We report on two recent calculations of QCD corrections to neutralino annihilation cross sections: (1) the next-to-leading order corrections to chi chi -> g g, and (2) the contribution to the cross section for chi chi -> q qbar g arising from interference between the tree-level and loop-induced processes.
1208.1017
Gaber Faisel Dr
Yan-Min Dai, Gaber Faisel, Dong-Won Jung, Otto C. W. Kong
Majorana versus Dirac mass from holomorphic supersymmetric Nambu-Jona-Lasinio Model
15 pages, 1 figure. Revised version matches the accepted one for publication in Phy.Rev.D Journal
Phys. Rev. D 87 (2013) 085033
10.1103/PhysRevD.87.085033
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the theoretical features in relation to dynamical mass generation and symmetry breaking for the recently proposed holomorphic supersymmetric Nambu--Jona-Lasinio model. The basic model has two different chiral superfields (multiplets) with a strongly coupled dimension five four-superfield interaction. In addition to the possibility of generation of Dirac mass between the pair established earlier, we show here the new option of generation of Majorana masses for each chiral superfield. We also give a first look at what condition may prefer Dirac over Majorana mass, illustrating that a split in the soft supersymmetry breaking masses is crucial. In particular, in the limit where one of the soft masses vanish, we show that generation of the Majorana mass is no longer an option, while the Dirac mass generation survives well. The latter is sensitive mostly to the average of the two soft masses. The result has positive implication on the application of the model framework towards dynamical electroweak symmetry breaking with Higgs superfields as composites.
[ { "created": "Sun, 5 Aug 2012 14:45:00 GMT", "version": "v1" }, { "created": "Thu, 16 Aug 2012 08:51:32 GMT", "version": "v2" }, { "created": "Fri, 29 Mar 2013 10:30:09 GMT", "version": "v3" } ]
2013-11-08
[ [ "Dai", "Yan-Min", "" ], [ "Faisel", "Gaber", "" ], [ "Jung", "Dong-Won", "" ], [ "Kong", "Otto C. W.", "" ] ]
We study the theoretical features in relation to dynamical mass generation and symmetry breaking for the recently proposed holomorphic supersymmetric Nambu--Jona-Lasinio model. The basic model has two different chiral superfields (multiplets) with a strongly coupled dimension five four-superfield interaction. In addition to the possibility of generation of Dirac mass between the pair established earlier, we show here the new option of generation of Majorana masses for each chiral superfield. We also give a first look at what condition may prefer Dirac over Majorana mass, illustrating that a split in the soft supersymmetry breaking masses is crucial. In particular, in the limit where one of the soft masses vanish, we show that generation of the Majorana mass is no longer an option, while the Dirac mass generation survives well. The latter is sensitive mostly to the average of the two soft masses. The result has positive implication on the application of the model framework towards dynamical electroweak symmetry breaking with Higgs superfields as composites.
2112.11468
Matheus Martines De Azevedo Da Silva
Oscar J.P. Eboli, M.C. Gonzalez-Garcia, and Matheus Martines
Electroweak HEFT after LHC run 2
19 pages, 7 figures
null
null
YITP-SB-2021-25
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the electroweak interactions in the framework of the Higgs effective field theory using the available Higgs and electroweak diboson production results from LHC run 2 as well as the electroweak precision data. Assuming universality of the weak current, our study considers 25 possible anomalous couplings. To unveil the nature of the Higgs boson, i.e. isosinglet versus part of SU(2)L doublet, we explore the correlation effects between observables that are predicted to exist in the linear realization of the electroweak gauge symmetry but not in its non-linear counterpart. This improves previous studies aimed at investigating the Higgs nature and the origin of the electroweak symmetry breaking.
[ { "created": "Tue, 21 Dec 2021 19:00:01 GMT", "version": "v1" } ]
2021-12-23
[ [ "Eboli", "Oscar J. P.", "" ], [ "Gonzalez-Garcia", "M. C.", "" ], [ "Martines", "Matheus", "" ] ]
We analyze the electroweak interactions in the framework of the Higgs effective field theory using the available Higgs and electroweak diboson production results from LHC run 2 as well as the electroweak precision data. Assuming universality of the weak current, our study considers 25 possible anomalous couplings. To unveil the nature of the Higgs boson, i.e. isosinglet versus part of SU(2)L doublet, we explore the correlation effects between observables that are predicted to exist in the linear realization of the electroweak gauge symmetry but not in its non-linear counterpart. This improves previous studies aimed at investigating the Higgs nature and the origin of the electroweak symmetry breaking.
hep-ph/0204076
D. Toublan
K. Splittorff, D. Toublan and J.J.M. Verbaarschot
Thermodynamics of chiral symmetry at low densities
29 pages, Latex, typos corrected, 1 Ref added. Version to appear in Nucl. Phys. B
Nucl.Phys. B639 (2002) 524-548
10.1016/S0550-3213(02)00440-6
SUNY-NTG-02/15
hep-ph cond-mat hep-lat hep-th
null
The phase diagram of two-color QCD as a function of temperature and baryon chemical potential is considered. Using a low-energy chiral Lagrangian based on the symmetries of the microscopic theory, we determine, at the one-loop level, the temperature dependence of the critical chemical potential for diquark condensation and the temperature dependence of the diquark condensate and baryon density. The prediction for the temperature dependence of the critical chemical potential is consistent with the one obtained for a dilute Bose gas. The associated phase transition is shown to be of second order for low temperatures and first order at higher temperatures. The tricritical point at which the second order phase transition ends is determined. The results are carried over to QCD with quarks in the adjoint representation and to ordinary QCD at a non-zero chemical potential for isospin.
[ { "created": "Fri, 5 Apr 2002 21:23:43 GMT", "version": "v1" }, { "created": "Fri, 28 Jun 2002 08:26:45 GMT", "version": "v2" } ]
2015-06-25
[ [ "Splittorff", "K.", "" ], [ "Toublan", "D.", "" ], [ "Verbaarschot", "J. J. M.", "" ] ]
The phase diagram of two-color QCD as a function of temperature and baryon chemical potential is considered. Using a low-energy chiral Lagrangian based on the symmetries of the microscopic theory, we determine, at the one-loop level, the temperature dependence of the critical chemical potential for diquark condensation and the temperature dependence of the diquark condensate and baryon density. The prediction for the temperature dependence of the critical chemical potential is consistent with the one obtained for a dilute Bose gas. The associated phase transition is shown to be of second order for low temperatures and first order at higher temperatures. The tricritical point at which the second order phase transition ends is determined. The results are carried over to QCD with quarks in the adjoint representation and to ordinary QCD at a non-zero chemical potential for isospin.
2311.14306
Hiroaki Kouno
Riki Oshima, Hiroaki Kouno, Kouji Kashiwa
Roberge-Weiss periodicity and singularity in hadron resonance gas model with excluded volume effects
11page, 17figures. (In the revised version, four references and some sentences have been added. )
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum chromodynamics (QCD) with pure imaginary baryon number chemical potential mu =i theta T, where T is temperature and theta is a real number, has the Roberge-Weiss periodicity. We study the theta-dependence of the baryon number density and the pressure in the hadron resonance gas model with excluded volume effects of baryons. It is shown that the baryon number density and the pressure are smooth periodic functions of theta at low or high temperature. However, they have singular behavior at theta =(2k+1)pi where k is an integer, when T sim 211MeV. This temperature is consistent with the Roberge-Weiss transition temperature TRW obtained by lattice QCD simulations. This singularity can be explained by the dual excluded volume effects in which the roles of point-like and non point-like particles are exchanged each other in the ordinary excluded volume effects. It is also indicated that the excluded volume effect is visible just below TRW and is directly detectable by the lattice QCD simulation at finite theta. We compare the results with the one obtained by the Polyakov-loop extended Nambu-Jona-Lasinio model.
[ { "created": "Fri, 24 Nov 2023 06:32:10 GMT", "version": "v1" }, { "created": "Wed, 31 Jan 2024 03:52:09 GMT", "version": "v2" } ]
2024-02-01
[ [ "Oshima", "Riki", "" ], [ "Kouno", "Hiroaki", "" ], [ "Kashiwa", "Kouji", "" ] ]
Quantum chromodynamics (QCD) with pure imaginary baryon number chemical potential mu =i theta T, where T is temperature and theta is a real number, has the Roberge-Weiss periodicity. We study the theta-dependence of the baryon number density and the pressure in the hadron resonance gas model with excluded volume effects of baryons. It is shown that the baryon number density and the pressure are smooth periodic functions of theta at low or high temperature. However, they have singular behavior at theta =(2k+1)pi where k is an integer, when T sim 211MeV. This temperature is consistent with the Roberge-Weiss transition temperature TRW obtained by lattice QCD simulations. This singularity can be explained by the dual excluded volume effects in which the roles of point-like and non point-like particles are exchanged each other in the ordinary excluded volume effects. It is also indicated that the excluded volume effect is visible just below TRW and is directly detectable by the lattice QCD simulation at finite theta. We compare the results with the one obtained by the Polyakov-loop extended Nambu-Jona-Lasinio model.
hep-ph/9611246
Gordon Ramsey
Gordon P. Ramsey (Loyola U Chicago and ANL)
Polarized Parton Distributions: Theory and Experiments
15 pages, 3 figures, LaTeX. To appear in the proceedings of the Circum-Pan-Pacific Workshop on High Energy Spin Physics 96, Kobe, Japan, 2-4 October, 1996
null
null
null
hep-ph
null
I review the constituent contributions to the spin of the proton extracted from recent data at CERN, SLAC and DESY. The valence, sea quark and antiquark spin-weighted distributions are determined separately. The data appear to imply a small to moderate polarized gluon distribution, so that the anomaly term is not significant in determining these contributions. We have analyzed the consistency of the results obtained from various sets of data and the Bjorken Sum Rule. All data are consistent with the sum rule, but they differ in the contribution of the strange sea to proton spin. This and the remaining uncertainty in the polarized gluon distribution pose unanswered questions about hadronic spin. Further experiments are suggested which can extract information about the polarized gluon and sea to address these questions.
[ { "created": "Tue, 5 Nov 1996 22:36:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ramsey", "Gordon P.", "", "Loyola U Chicago and ANL" ] ]
I review the constituent contributions to the spin of the proton extracted from recent data at CERN, SLAC and DESY. The valence, sea quark and antiquark spin-weighted distributions are determined separately. The data appear to imply a small to moderate polarized gluon distribution, so that the anomaly term is not significant in determining these contributions. We have analyzed the consistency of the results obtained from various sets of data and the Bjorken Sum Rule. All data are consistent with the sum rule, but they differ in the contribution of the strange sea to proton spin. This and the remaining uncertainty in the polarized gluon distribution pose unanswered questions about hadronic spin. Further experiments are suggested which can extract information about the polarized gluon and sea to address these questions.
hep-ph/0406030
Roberto Casalbuoni
R. Casalbuoni and G. Nardulli
Skyrmions and pentaquarks in the quark-hadron continuity perspective
12 pages, LaTex. 2 figures. Final version for Physics Letters B
Phys.Lett. B602 (2004) 205-211
10.1016/j.physletb.2004.10.010
BARI-TH 490/04, DFF-418/06/04
hep-ph
null
We argue that in the color-flavor-locking (CFL) superconducting phase classical soliton solutions can exist, whose excitations should be interpreted as states formed by a quark (or an antiquark) and condensed diquarks. This finding extends the picture of quark-hadron-continuity showing the existence of a region, intermediate between the CFL and the hypernuclear phase, where chiral solitons and Nambu Goldstone bosons can exist. We derive an expression of the soliton mass in terms of the QCD coupling, $g_s$, and the Nambu Goldstone boson parameters. From the quark-hadron continuity we can draw an argument in favor of the interpretation of the $\Theta^+(1540)$ particle in terms of a strange antiquark and two highly correlated $ud$ pairs (diquarks).
[ { "created": "Wed, 2 Jun 2004 18:04:13 GMT", "version": "v1" }, { "created": "Thu, 14 Oct 2004 09:38:28 GMT", "version": "v2" } ]
2009-11-10
[ [ "Casalbuoni", "R.", "" ], [ "Nardulli", "G.", "" ] ]
We argue that in the color-flavor-locking (CFL) superconducting phase classical soliton solutions can exist, whose excitations should be interpreted as states formed by a quark (or an antiquark) and condensed diquarks. This finding extends the picture of quark-hadron-continuity showing the existence of a region, intermediate between the CFL and the hypernuclear phase, where chiral solitons and Nambu Goldstone bosons can exist. We derive an expression of the soliton mass in terms of the QCD coupling, $g_s$, and the Nambu Goldstone boson parameters. From the quark-hadron continuity we can draw an argument in favor of the interpretation of the $\Theta^+(1540)$ particle in terms of a strange antiquark and two highly correlated $ud$ pairs (diquarks).
1707.05644
Konstantinos Dimopoulos
Konstantinos Dimopoulos
Ultra slow-roll inflation demystified
10 pages, published version
null
10.1016/j.physletb.2017.10.066
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultra-slow-roll (USR) inflation is a new mode of inflation which corresponds to the occasions when the inflaton field must traverse an extremely flat part of the scalar potential, when the usual slow-roll (SR) fails. We investigate USR and obtain an estimate for how long it lasts, given the initial kinetic density of the inflaton. We also find that, if the initial kinetic density is small enough, USR can be avoided and the usual SR treatment is valid. This has important implications for inflection-point inflation.
[ { "created": "Tue, 18 Jul 2017 14:33:18 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 2017 10:47:46 GMT", "version": "v2" }, { "created": "Wed, 15 Nov 2017 15:54:02 GMT", "version": "v3" } ]
2017-12-06
[ [ "Dimopoulos", "Konstantinos", "" ] ]
Ultra-slow-roll (USR) inflation is a new mode of inflation which corresponds to the occasions when the inflaton field must traverse an extremely flat part of the scalar potential, when the usual slow-roll (SR) fails. We investigate USR and obtain an estimate for how long it lasts, given the initial kinetic density of the inflaton. We also find that, if the initial kinetic density is small enough, USR can be avoided and the usual SR treatment is valid. This has important implications for inflection-point inflation.
hep-ph/9904382
Marek Jezabek
M. Jezabek and Y. Sumino
Neutrino Masses and Bimaximal Mixing
Latex, 13 p., no figures
Phys.Lett. B457 (1999) 139-146
10.1016/S0370-2693(99)00517-1
TP-USl/99/03 and TU-563
hep-ph
null
Solar and atmospheric neutrino anomalies are described by bimaximal mixing of three neutrinos. Neutrino oscillations in appearance nu_e <--> nu_mu,nu_tau and in disappearance nu_e long baseline and atmospheric experiments are sensitive to deviations from the ideal bimaximal mixing. It is suggested that these deviations may be dominated by a rotation in the electron--muon plane of the generation space. Simple seesaw models are described supporting this idea. The rotation angle is estimated from Fritzsch's relation. Predictions are presented for oscillations in long baseline experiments, for solar neutrinos, and for the rates of neutrinoless double beta decays.
[ { "created": "Mon, 19 Apr 1999 15:53:29 GMT", "version": "v1" } ]
2009-10-31
[ [ "Jezabek", "M.", "" ], [ "Sumino", "Y.", "" ] ]
Solar and atmospheric neutrino anomalies are described by bimaximal mixing of three neutrinos. Neutrino oscillations in appearance nu_e <--> nu_mu,nu_tau and in disappearance nu_e long baseline and atmospheric experiments are sensitive to deviations from the ideal bimaximal mixing. It is suggested that these deviations may be dominated by a rotation in the electron--muon plane of the generation space. Simple seesaw models are described supporting this idea. The rotation angle is estimated from Fritzsch's relation. Predictions are presented for oscillations in long baseline experiments, for solar neutrinos, and for the rates of neutrinoless double beta decays.
0804.3008
Roman Nikolaevich Lee
R.N. Lee
Group structure of the integration-by-part identities and its application to the reduction of multiloop integrals
6 pages, RevTeX. Version, published in JHEP, references corrected
JHEP0807:031,2008
10.1088/1126-6708/2008/07/031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The excessiveness of integration-by-part (IBP) identities is discussed. The Lie-algebraic structure of the IBP identities is used to reduce the number of the IBP equations to be considered. It is shown that Lorentz-invariance (LI) identities do not bring any information additional to that contained in the IBP identities, and therefore, can be discarded.
[ { "created": "Fri, 18 Apr 2008 12:54:19 GMT", "version": "v1" }, { "created": "Fri, 8 Aug 2008 13:14:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lee", "R. N.", "" ] ]
The excessiveness of integration-by-part (IBP) identities is discussed. The Lie-algebraic structure of the IBP identities is used to reduce the number of the IBP equations to be considered. It is shown that Lorentz-invariance (LI) identities do not bring any information additional to that contained in the IBP identities, and therefore, can be discarded.
1105.0756
Bingfang Yang
Bingfang Yang, Jinzhong Han, Lin Wang and Xuelei Wang
Top quark pair production via $e^{+}e^{-}$ collision in the littlest Higgs model with T-parity at the ILC
null
Phys.Rev.D83:094020,2011
10.1103/PhysRevD.83.094020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the littlest Higgs model with T-parity, we studied the contributions of the new particles to the top-quark pair production via $e^{+}e^{-}$ collision at the International Linear Collider. We calculated the top-quark pair production cross section and found this process can generate significantly relative correction. The result may be a sensitive probe of the littlest Higgs model with T-parity.
[ { "created": "Wed, 4 May 2011 08:25:28 GMT", "version": "v1" }, { "created": "Sun, 11 Sep 2011 08:09:41 GMT", "version": "v2" }, { "created": "Sat, 26 May 2012 09:37:35 GMT", "version": "v3" }, { "created": "Tue, 29 May 2012 02:44:18 GMT", "version": "v4" } ]
2012-05-30
[ [ "Yang", "Bingfang", "" ], [ "Han", "Jinzhong", "" ], [ "Wang", "Lin", "" ], [ "Wang", "Xuelei", "" ] ]
In the littlest Higgs model with T-parity, we studied the contributions of the new particles to the top-quark pair production via $e^{+}e^{-}$ collision at the International Linear Collider. We calculated the top-quark pair production cross section and found this process can generate significantly relative correction. The result may be a sensitive probe of the littlest Higgs model with T-parity.
hep-ph/0406266
Pavlos Pasipoularides
K. Farakos and P. Pasipoularides
Effective potential analysis for 5D SU(2) gauge theories at finite temperature and radius
18 pages, 7 figures ; typos corrected
Nucl.Phys. B705 (2005) 92-110
10.1016/j.nuclphysb.2004.11.044
null
hep-ph hep-lat hep-th
null
We calculate the one loop effective potential for a 5D SU(2) gauge field theory at finite temperature $T=1/\beta$ and radius R=1/M. This calculation is performed, for the first time, in the case of background fields with two constant components $A^{3}_{y}$ (directed towards the compact extra dimension with radius R) and $A^{3}_{\tau}$ (directed towards the compact Euclidean time with radius $\beta$). This model possesses two discrete symmetries known as Z_{M}(2) and Z_{T}(2). The corresponding phase diagram is presented in Ref. 4. However the arguments which lead to this diagram are mainly qualitative. We present a detailed analysis, from our point of view, for this phase diagram, and we support our arguments performing lattice simulations for a simple phenomenological model with two scalar fields interacting through the previously calculated potential.
[ { "created": "Thu, 24 Jun 2004 00:24:50 GMT", "version": "v1" }, { "created": "Sat, 3 Jul 2004 06:31:16 GMT", "version": "v2" } ]
2009-11-10
[ [ "Farakos", "K.", "" ], [ "Pasipoularides", "P.", "" ] ]
We calculate the one loop effective potential for a 5D SU(2) gauge field theory at finite temperature $T=1/\beta$ and radius R=1/M. This calculation is performed, for the first time, in the case of background fields with two constant components $A^{3}_{y}$ (directed towards the compact extra dimension with radius R) and $A^{3}_{\tau}$ (directed towards the compact Euclidean time with radius $\beta$). This model possesses two discrete symmetries known as Z_{M}(2) and Z_{T}(2). The corresponding phase diagram is presented in Ref. 4. However the arguments which lead to this diagram are mainly qualitative. We present a detailed analysis, from our point of view, for this phase diagram, and we support our arguments performing lattice simulations for a simple phenomenological model with two scalar fields interacting through the previously calculated potential.
2107.08206
Guoxing Wang
Guoxing Wang, Xiaofeng Xu, Yongqi Xu, Li Lin Yang
Next-to-leading order corrections for $gg \to ZH$ with top quark mass dependence
null
null
10.1016/j.physletb.2022.137087
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Letter, we present for the first time a calculation of the complete next-to-leading order corrections to the $gg \to ZH$ process. We use the method of small mass expansion to tackle the most challenging two-loop virtual amplitude, in which the top quark mass dependence is retained throughout the calculations. We show that our method provides reliable numeric results in all kinematic regions, and present phenomenological predictions for the total and differential cross sections at the Large Hadron Collider and its future upgrades. Our results are necessary ingredients towards reducing the theoretical uncertainties of the $pp \to ZH$ cross sections down to the percent-level, and provide important theoretical inputs for future precision experimental collider programs.
[ { "created": "Sat, 17 Jul 2021 08:52:59 GMT", "version": "v1" }, { "created": "Mon, 19 Sep 2022 06:23:09 GMT", "version": "v2" } ]
2022-09-20
[ [ "Wang", "Guoxing", "" ], [ "Xu", "Xiaofeng", "" ], [ "Xu", "Yongqi", "" ], [ "Yang", "Li Lin", "" ] ]
In this Letter, we present for the first time a calculation of the complete next-to-leading order corrections to the $gg \to ZH$ process. We use the method of small mass expansion to tackle the most challenging two-loop virtual amplitude, in which the top quark mass dependence is retained throughout the calculations. We show that our method provides reliable numeric results in all kinematic regions, and present phenomenological predictions for the total and differential cross sections at the Large Hadron Collider and its future upgrades. Our results are necessary ingredients towards reducing the theoretical uncertainties of the $pp \to ZH$ cross sections down to the percent-level, and provide important theoretical inputs for future precision experimental collider programs.
0705.3082
Xiang Liu
Bo Zhang, Xiang Liu and Shi-Lin Zhu
The dispersive contribution of $\rho(1450,1700)$ decays and X(1576)
4 pages, 4 figures
Chin.Phys.Lett.24:2537-2539,2007
10.1088/0256-307X/24/9/020
null
hep-ph
null
We study whether the broad enhancement X(1576) arises from the final state interaction (FSI) of $\rho(1450,1700)\to \rho^+\rho^-\to K^{+}K^{-}$ decays. We consider both the absorptive and dispersive contribution of the above amplitudes since the intermediate states are very close to $\rho(1450,1700)$. The same mechanism leads to a similar enhancement around 1580 MeV in the $\pi^{+}\pi^-$ spectrum in the $J/\psi\to \pi^{0}\pi^{+}\pi^{-}$ channel, which can be used to test whether X(1576) can be ascribed to the FSI effect of $\rho(1450,1700)\to \rho^+\rho^-$.
[ { "created": "Tue, 22 May 2007 05:41:28 GMT", "version": "v1" }, { "created": "Sun, 24 Jun 2007 01:48:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Zhang", "Bo", "" ], [ "Liu", "Xiang", "" ], [ "Zhu", "Shi-Lin", "" ] ]
We study whether the broad enhancement X(1576) arises from the final state interaction (FSI) of $\rho(1450,1700)\to \rho^+\rho^-\to K^{+}K^{-}$ decays. We consider both the absorptive and dispersive contribution of the above amplitudes since the intermediate states are very close to $\rho(1450,1700)$. The same mechanism leads to a similar enhancement around 1580 MeV in the $\pi^{+}\pi^-$ spectrum in the $J/\psi\to \pi^{0}\pi^{+}\pi^{-}$ channel, which can be used to test whether X(1576) can be ascribed to the FSI effect of $\rho(1450,1700)\to \rho^+\rho^-$.
1510.04694
Volodymyr Takhistov
Mu-Chun Chen, Jinrui Huang and Volodymyr Takhistov
Beyond Minimal Lepton Flavored Dark Matter
30 pages, 12 figures; minor corrections, added references and discussion on decaying dark matter, matches published version
JHEP 1602 (2016) 60
10.1007/JHEP02(2016)060
UCI-TR-2015-17, LA-UR-15-27938
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a class of flavored dark matter (DM) theories where dark matter interacts with the Standard Model lepton fields at the renormalizable level. We allow for a general coupling matrix between the dark matter and leptons whose structure is beyond the one permitted by the minimal flavor violation (MFV) assumption. It is assumed that this is the only new source of flavor violation in addition to the Standard Model (SM) Yukawa interactions. The setup can be described by augmenting the SM flavor symmetry by an additional $\mathrm{SU}(3)_{\chi}$, under which the dark matter $\chi$ transforms. This framework is especially phenomenologically rich, due to possible novel flavor-changing interactions which are not present within the more restrictive MFV framework. As a representative case study of this setting, which we call "beyond MFV" (BMFV), we consider Dirac fermion dark matter which transforms as a singlet under the SM gauge group and a triplet under $\mathrm{SU}(3)_{\chi}$. The DM fermion couples to the SM lepton sector through a scalar mediator $\phi$. Unlike the case of quark-flavored DM, we show that there is no $\mathbb{Z}_3$ symmetry within either the MFV or BMFV settings which automatically stabilizes the lepton-flavored DM. We discuss constraints on this setup from flavor-changing processes, DM relic abundance as well as direct and indirect detections. We find that relatively large flavor-changing couplings are possible, while the dark matter mass is still within the phenomenologically interesting region below the TeV scale. Collider signatures which can be potentially searched for at the lepton and hadron colliders are discussed. Finally, we discuss the implications for decaying dark matter, which can appear if an additional stabilizing symmetry is not imposed.
[ { "created": "Thu, 15 Oct 2015 20:03:19 GMT", "version": "v1" }, { "created": "Tue, 16 Feb 2016 09:42:29 GMT", "version": "v2" } ]
2016-02-17
[ [ "Chen", "Mu-Chun", "" ], [ "Huang", "Jinrui", "" ], [ "Takhistov", "Volodymyr", "" ] ]
We consider a class of flavored dark matter (DM) theories where dark matter interacts with the Standard Model lepton fields at the renormalizable level. We allow for a general coupling matrix between the dark matter and leptons whose structure is beyond the one permitted by the minimal flavor violation (MFV) assumption. It is assumed that this is the only new source of flavor violation in addition to the Standard Model (SM) Yukawa interactions. The setup can be described by augmenting the SM flavor symmetry by an additional $\mathrm{SU}(3)_{\chi}$, under which the dark matter $\chi$ transforms. This framework is especially phenomenologically rich, due to possible novel flavor-changing interactions which are not present within the more restrictive MFV framework. As a representative case study of this setting, which we call "beyond MFV" (BMFV), we consider Dirac fermion dark matter which transforms as a singlet under the SM gauge group and a triplet under $\mathrm{SU}(3)_{\chi}$. The DM fermion couples to the SM lepton sector through a scalar mediator $\phi$. Unlike the case of quark-flavored DM, we show that there is no $\mathbb{Z}_3$ symmetry within either the MFV or BMFV settings which automatically stabilizes the lepton-flavored DM. We discuss constraints on this setup from flavor-changing processes, DM relic abundance as well as direct and indirect detections. We find that relatively large flavor-changing couplings are possible, while the dark matter mass is still within the phenomenologically interesting region below the TeV scale. Collider signatures which can be potentially searched for at the lepton and hadron colliders are discussed. Finally, we discuss the implications for decaying dark matter, which can appear if an additional stabilizing symmetry is not imposed.
2105.00915
Ziyue Wang
Ziyue Wang and Pengfei Zhuang
Damping and polarization rates in near equilibrium state
14 pages, 1 figure
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
The collision terms in spin transport theory are analyzed in Kadanoff-Baym formalism for systems close to equilibrium. The non-equilibrium fluctuations in spin distribution include both damping and polarization, with the latter arising from the exchange between orbital and spin angular momenta. The damping and polarization rates or the relaxation times are expressed in terms of various Dirac components of the self-energy. Unlike the usually used Anderson-Witting relaxation time approximation assuming a single time scale for different degrees of freedom, the polarization effect is induced by the thermal vorticity and its time scale of thermalization is different from the damping. The numerical calculation in the Nambu--Jona-Lasinio model shows that, charge is thermalized earlier and spin is thermalized later.
[ { "created": "Mon, 3 May 2021 14:50:26 GMT", "version": "v1" } ]
2021-05-04
[ [ "Wang", "Ziyue", "" ], [ "Zhuang", "Pengfei", "" ] ]
The collision terms in spin transport theory are analyzed in Kadanoff-Baym formalism for systems close to equilibrium. The non-equilibrium fluctuations in spin distribution include both damping and polarization, with the latter arising from the exchange between orbital and spin angular momenta. The damping and polarization rates or the relaxation times are expressed in terms of various Dirac components of the self-energy. Unlike the usually used Anderson-Witting relaxation time approximation assuming a single time scale for different degrees of freedom, the polarization effect is induced by the thermal vorticity and its time scale of thermalization is different from the damping. The numerical calculation in the Nambu--Jona-Lasinio model shows that, charge is thermalized earlier and spin is thermalized later.
hep-ph/9711366
Erwin Mirkes
E. Mirkes, S. Willfahrt and D. Zeppenfeld
Jet Production in DIS at NLO Including Z and W Exchange
Talk given by E. Mirkes at the International Europhysics Conference on High-Energy Physics (HEP 97), Jerusalem, Israel, 19-26 Aug 1997. Latex, 2 pages, 1 figure. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
null
null
TTP97-47
hep-ph
null
Next-to-leading order QCD predictions for 1-jet and 2-jet cross sections in deep inelastic scattering with complete neutral current ($\gamma^*$ and $Z$) and charged current ($W^\pm$) exchange are presented.
[ { "created": "Tue, 18 Nov 1997 10:22:33 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mirkes", "E.", "" ], [ "Willfahrt", "S.", "" ], [ "Zeppenfeld", "D.", "" ] ]
Next-to-leading order QCD predictions for 1-jet and 2-jet cross sections in deep inelastic scattering with complete neutral current ($\gamma^*$ and $Z$) and charged current ($W^\pm$) exchange are presented.
1902.03602
Vadim Egorov
Vadim O. Egorov, Igor P. Volobuev
Coherence length of neutrino oscillations in quantum field-theoretical approach
LaTex, 18 pages, 15 figures. Multiple adjustments
Phys. Rev. D 100, 033004 (2019)
10.1103/PhysRevD.100.033004
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a novel quantum field-theoretical approach to the description of processes passing at finite space-time intervals based on the Feynman diagram technique in the coordinate representation. The most known processes of this type are neutrino and neutral kaon oscillations. The experimental setting of these processes requires one to adjust the rules of passing to the momentum representation in the Feynman diagram technique in accordance with it, which leads to a modification of the Feynman propagator in the momentum representation. The approach does not make use of wave packets, both initial and final particle states are described by plane waves, which simplifies the calculations considerably. We consider neutrino oscillation processes, where the neutrinos are produced in three-particle weak decays of nuclei and detected in the charged-current interaction with nuclei or in the charged- and neutral-current interactions with electrons. Particular examples are considered and it is shown that the momentum spread of the produced neutrinos and the energy dependence of the differential cross section of the detection process result in the suppression of neutrino oscillation, which is characterized by a coherence length specific for a pair of production and detection processes. This coherence length turns out to be much less than the coherence length in the standard quantum-mechanical approach defined by the quantum uncertainty of neutrino momentum.
[ { "created": "Sun, 10 Feb 2019 13:56:06 GMT", "version": "v1" }, { "created": "Mon, 18 Feb 2019 13:44:57 GMT", "version": "v2" }, { "created": "Sun, 24 Mar 2019 18:22:02 GMT", "version": "v3" } ]
2019-08-28
[ [ "Egorov", "Vadim O.", "" ], [ "Volobuev", "Igor P.", "" ] ]
We consider a novel quantum field-theoretical approach to the description of processes passing at finite space-time intervals based on the Feynman diagram technique in the coordinate representation. The most known processes of this type are neutrino and neutral kaon oscillations. The experimental setting of these processes requires one to adjust the rules of passing to the momentum representation in the Feynman diagram technique in accordance with it, which leads to a modification of the Feynman propagator in the momentum representation. The approach does not make use of wave packets, both initial and final particle states are described by plane waves, which simplifies the calculations considerably. We consider neutrino oscillation processes, where the neutrinos are produced in three-particle weak decays of nuclei and detected in the charged-current interaction with nuclei or in the charged- and neutral-current interactions with electrons. Particular examples are considered and it is shown that the momentum spread of the produced neutrinos and the energy dependence of the differential cross section of the detection process result in the suppression of neutrino oscillation, which is characterized by a coherence length specific for a pair of production and detection processes. This coherence length turns out to be much less than the coherence length in the standard quantum-mechanical approach defined by the quantum uncertainty of neutrino momentum.
hep-ph/9505357
Michael Goodband
M.Goodband and M.Hindmarsh
Instabilities of Electroweak Strings
Latex, 11 pages, 1 uuencoded figure
Phys.Lett. B363 (1995) 58-64
10.1016/0370-2693(95)01198-Y
SUSX-TH-95/72
hep-ph hep-th
null
We investigate the instabilities of low winding number electroweak strings using standard numerical techniques of linear algebra. For strings of unit winding we are able to confirm and extend existing calculations of the unstable region in the ($m_H/m_W,\sin^2\theta_W$) plane. For strings of higher winding number we map the unstable regions for the various decay modes.
[ { "created": "Mon, 22 May 1995 16:49:35 GMT", "version": "v1" } ]
2009-10-28
[ [ "Goodband", "M.", "" ], [ "Hindmarsh", "M.", "" ] ]
We investigate the instabilities of low winding number electroweak strings using standard numerical techniques of linear algebra. For strings of unit winding we are able to confirm and extend existing calculations of the unstable region in the ($m_H/m_W,\sin^2\theta_W$) plane. For strings of higher winding number we map the unstable regions for the various decay modes.
1109.1565
Abhishek Kumar
Abhishek Kumar, David E. Morrissey, and Andrew Spray
Kinetically-Enhanced Anomaly Mediation
29 pages, 10 figures; Added references, corrected ctau plot in Fig. 4, same general conclusions
null
10.1007/JHEP12(2011)013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a modification of anomaly-mediated supersymmetry breaking (AMSB) with an exotic U(1)_x gauge sector that can solve the tachyonic slepton problem of minimal AMSB scenarios. The new U(1)_x multiplet is assumed to couple directly to the source of supersymmetry breaking, but only indirectly to the minimal supersymmetric Standard Model (MSSM) through kinetic mixing with hypercharge. If the MSSM sector is also sequestered from the source of supersymmetry breaking, the contributions to the MSSM soft terms come from both AMSB and the U(1)_x kinetic coupling. We find that this arrangement can give rise to a flavour-universal, phenomenologically viable, and distinctive spectrum of MSSM superpartners. We also investigate the prospects for discovery and the most likely signatures of this scenario at the Large Hadron Collider (LHC).
[ { "created": "Wed, 7 Sep 2011 20:03:43 GMT", "version": "v1" }, { "created": "Sat, 24 Sep 2011 03:39:08 GMT", "version": "v2" } ]
2015-05-30
[ [ "Kumar", "Abhishek", "" ], [ "Morrissey", "David E.", "" ], [ "Spray", "Andrew", "" ] ]
We investigate a modification of anomaly-mediated supersymmetry breaking (AMSB) with an exotic U(1)_x gauge sector that can solve the tachyonic slepton problem of minimal AMSB scenarios. The new U(1)_x multiplet is assumed to couple directly to the source of supersymmetry breaking, but only indirectly to the minimal supersymmetric Standard Model (MSSM) through kinetic mixing with hypercharge. If the MSSM sector is also sequestered from the source of supersymmetry breaking, the contributions to the MSSM soft terms come from both AMSB and the U(1)_x kinetic coupling. We find that this arrangement can give rise to a flavour-universal, phenomenologically viable, and distinctive spectrum of MSSM superpartners. We also investigate the prospects for discovery and the most likely signatures of this scenario at the Large Hadron Collider (LHC).
2303.01530
Xiaohui Liu
Haotian Cao, Xiaohui Liu, Hua Xing Zhu
Towards the Precision Nucleon Energy-Energy Correlator in Lepton-Ion Collisions
17 pages, 3 figures
null
null
null
hep-ph hep-ex nucl-ex
http://creativecommons.org/licenses/by/4.0/
The nucleon energy-energy correlator (NEEC) was proposed in 2209.02080 as a new way of studying nucleon intrinsic dynamics. In this work, we present a detailed derivation of the factorization theorem that enables the measurement of the unpolarized NEEC in lepton-ion collisions. As a first step towards a precise measurement of this quantity, we obtained the next-to-leading-logarithmic (NLL, $\sim{\cal O}(\alpha_s^n L^{n-1})$) resummation in a concise analytic form, and predicted the analytic $\theta$-angle distribution at ${\cal O}(\alpha^2_s)$. Extending our analytic resummation formula to higher logarithmic accuracy and the factorization theorem to hadron-hadron collisions is straightforward.
[ { "created": "Thu, 2 Mar 2023 19:00:15 GMT", "version": "v1" } ]
2023-03-06
[ [ "Cao", "Haotian", "" ], [ "Liu", "Xiaohui", "" ], [ "Zhu", "Hua Xing", "" ] ]
The nucleon energy-energy correlator (NEEC) was proposed in 2209.02080 as a new way of studying nucleon intrinsic dynamics. In this work, we present a detailed derivation of the factorization theorem that enables the measurement of the unpolarized NEEC in lepton-ion collisions. As a first step towards a precise measurement of this quantity, we obtained the next-to-leading-logarithmic (NLL, $\sim{\cal O}(\alpha_s^n L^{n-1})$) resummation in a concise analytic form, and predicted the analytic $\theta$-angle distribution at ${\cal O}(\alpha^2_s)$. Extending our analytic resummation formula to higher logarithmic accuracy and the factorization theorem to hadron-hadron collisions is straightforward.
hep-ph/0110227
Ben Allanach
B.C. Allanach
Theoretical Uncertainties in Sparticle Mass Predictions
revTex4 style. Softsusy homepage is at http://allanach.home.cern.ch/allanach/softsusy.html Written for Snowmass 2001. Replaced version has updated reference. 3 pages, 3 figures
eConf C010630 (2001) P319
null
CERN-TH/2001-255
hep-ph
null
We contrast the sparticle spectra obtained from three modern publicly available codes along model lines in minimal supersymmetric standard model (MSSM) parameter space. From this we gain an idea of the uncertainties involved with sparticle spectra calculations. The differences in predicted sparticle masses are typically at the several percent-level. In the focus-point scenario, there are differences of 30% in the weak gaugino masses. These uncertainties need to be reduced in order to obtain accurate information about fundamental models of supersymmetry breaking.
[ { "created": "Wed, 17 Oct 2001 09:58:47 GMT", "version": "v1" }, { "created": "Sun, 11 Nov 2001 12:38:46 GMT", "version": "v2" } ]
2007-05-23
[ [ "Allanach", "B. C.", "" ] ]
We contrast the sparticle spectra obtained from three modern publicly available codes along model lines in minimal supersymmetric standard model (MSSM) parameter space. From this we gain an idea of the uncertainties involved with sparticle spectra calculations. The differences in predicted sparticle masses are typically at the several percent-level. In the focus-point scenario, there are differences of 30% in the weak gaugino masses. These uncertainties need to be reduced in order to obtain accurate information about fundamental models of supersymmetry breaking.
1205.2943
Xianhui Zhong
Lei-Hua Liu, Li-Ye Xiao and Xian-Hui Zhong
Charm-strange baryon strong decays in a chiral quark model
15 pages, 9 figures
null
10.1103/PhysRevD.86.034024
null
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/3.0/
The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, $\Xi_c^*(2645)$, $\Xi_c(2790)$ and $\Xi_c(2815)$, are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$. Our predictions are given as follows. (i) $\Xi_c(2930)$ might be the first $P$-wave excitation of $\Xi_c'$ with $J^P=1/2^-$, favors the $|\Xi_c'\ ^2P_\lambda 1/2^->$ or $|\Xi_c'\ ^4P_\lambda 1/2^->$ state. (ii) $\Xi_c(2980)$ might correspond to two overlapping $P$-wave states $|\Xi_c'\ ^2P_\rho 1/2^->$ and $|\Xi_c'\ ^2P_\rho 3/2^->$, respectively. The $\Xi_c(2980)$ observed in the $\Lambda_c^+\bar{K}\pi$ final state is most likely to be the $|\Xi_c'\ ^2P_\rho 1/2^->$ state, while the narrower resonance with a mass $m\simeq 2.97$ GeV observed in the $\Xi_c^*(2645)\pi$ channel favors to be assigned to the $|\Xi_c'\ ^2P_\rho 3/2^->$ state. (iii) $\Xi_c(3080)$ favors to be classified as the $|\Xi_c\ S_{\rho\rho} 1/2^+>$ state, i.e., the first radial excitation (2S) of $\Xi_c$. (iv) $\Xi_c(3055)$ is most likely to be the first $D$-wave excitation of $\Xi_c$ with $J^P=3/2^+$, favors the $|\Xi_c\ ^2D_{\lambda\lambda} 3/2^+>$ state. (v) $\Xi_c(3123)$ might be assigned to the $|\Xi_c'\ ^4D_{\lambda\lambda} 3/2^+>$, $|\Xi_c'\ ^4D_{\lambda\lambda} 5/2^+>$, or $|\Xi_c\ ^2D_{\rho\rho} 5/2^+>$ state. As a by-product, we calculate the strong decays of the bottom baryons $\Sigma_b^{\pm}$, $\Sigma_b^{*\pm}$ and $\Xi_b^*$, which are in good agreement with the recent observations as well.
[ { "created": "Mon, 14 May 2012 06:01:17 GMT", "version": "v1" } ]
2013-05-30
[ [ "Liu", "Lei-Hua", "" ], [ "Xiao", "Li-Ye", "" ], [ "Zhong", "Xian-Hui", "" ] ]
The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, $\Xi_c^*(2645)$, $\Xi_c(2790)$ and $\Xi_c(2815)$, are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$. Our predictions are given as follows. (i) $\Xi_c(2930)$ might be the first $P$-wave excitation of $\Xi_c'$ with $J^P=1/2^-$, favors the $|\Xi_c'\ ^2P_\lambda 1/2^->$ or $|\Xi_c'\ ^4P_\lambda 1/2^->$ state. (ii) $\Xi_c(2980)$ might correspond to two overlapping $P$-wave states $|\Xi_c'\ ^2P_\rho 1/2^->$ and $|\Xi_c'\ ^2P_\rho 3/2^->$, respectively. The $\Xi_c(2980)$ observed in the $\Lambda_c^+\bar{K}\pi$ final state is most likely to be the $|\Xi_c'\ ^2P_\rho 1/2^->$ state, while the narrower resonance with a mass $m\simeq 2.97$ GeV observed in the $\Xi_c^*(2645)\pi$ channel favors to be assigned to the $|\Xi_c'\ ^2P_\rho 3/2^->$ state. (iii) $\Xi_c(3080)$ favors to be classified as the $|\Xi_c\ S_{\rho\rho} 1/2^+>$ state, i.e., the first radial excitation (2S) of $\Xi_c$. (iv) $\Xi_c(3055)$ is most likely to be the first $D$-wave excitation of $\Xi_c$ with $J^P=3/2^+$, favors the $|\Xi_c\ ^2D_{\lambda\lambda} 3/2^+>$ state. (v) $\Xi_c(3123)$ might be assigned to the $|\Xi_c'\ ^4D_{\lambda\lambda} 3/2^+>$, $|\Xi_c'\ ^4D_{\lambda\lambda} 5/2^+>$, or $|\Xi_c\ ^2D_{\rho\rho} 5/2^+>$ state. As a by-product, we calculate the strong decays of the bottom baryons $\Sigma_b^{\pm}$, $\Sigma_b^{*\pm}$ and $\Xi_b^*$, which are in good agreement with the recent observations as well.
0911.3761
Paramita Dey
Paramita Dey, Biswarup Mukhopadhyaya, Soumitra SenGupta
Bulk Higgs field in a Randall-Sundrum model with nonvanishing brane cosmological constant
7 pages, 2 tables, version accepted for publication
Phys.Rev.D81:036011,2010
10.1103/PhysRevD.81.036011
PITHA 09/32, RECAPP-HRI-2009-021
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the possibility of Higgs mechanism in the bulk in a generalised Randall-Sundrum model, where a nonvanishing cosmological constant is induced on the visible brane. This scenario has the advantage of accommodating positive tension of the visible brane and thus ensures stability of the model. It is shown that several problems usually associated with this mechanism are avoided if some dimensionful parameters in the bulk are allowed to lie a little below the Planck mass. The most important of these is keeping the lowest massive mode in the scale of the standard electroweak model, and at the same time reducing the gauge coupling of the next excited state, thus ameliorating otherwise stringent phenomenological constraints.
[ { "created": "Thu, 19 Nov 2009 11:19:05 GMT", "version": "v1" }, { "created": "Tue, 16 Feb 2010 13:21:50 GMT", "version": "v2" } ]
2010-04-06
[ [ "Dey", "Paramita", "" ], [ "Mukhopadhyaya", "Biswarup", "" ], [ "SenGupta", "Soumitra", "" ] ]
We consider the possibility of Higgs mechanism in the bulk in a generalised Randall-Sundrum model, where a nonvanishing cosmological constant is induced on the visible brane. This scenario has the advantage of accommodating positive tension of the visible brane and thus ensures stability of the model. It is shown that several problems usually associated with this mechanism are avoided if some dimensionful parameters in the bulk are allowed to lie a little below the Planck mass. The most important of these is keeping the lowest massive mode in the scale of the standard electroweak model, and at the same time reducing the gauge coupling of the next excited state, thus ameliorating otherwise stringent phenomenological constraints.
hep-ph/9604207
Bernd Berg
Bernd A. Berg
New Algorithm to Investigate Neural Networks
16 pages and 8 figures. Typos in eqn.(1) and various misleading formulations eliminated
Comput.Phys.Commun. 98 (1996) 35-44
10.1016/0010-4655(96)00086-0
null
hep-ph hep-lat
null
Random cost simulations were introduced as a method to investigate optimization problems in systems with conflicting constraints. Here I study the approach in connection with the training of a feed-forward multilayer perceptron, as used in high energy physics applications. It is suggested to use random cost simulations for generating a set of selected configurations. On each of those final minimization may then be performed by a standard algorithm. For the training example at hand many almost degenerate local minima are thus found. Some effort is spend to discuss whether they lead to equivalent classifications of the data.
[ { "created": "Mon, 1 Apr 1996 19:13:05 GMT", "version": "v1" }, { "created": "Thu, 5 Sep 1996 17:57:55 GMT", "version": "v2" } ]
2009-10-28
[ [ "Berg", "Bernd A.", "" ] ]
Random cost simulations were introduced as a method to investigate optimization problems in systems with conflicting constraints. Here I study the approach in connection with the training of a feed-forward multilayer perceptron, as used in high energy physics applications. It is suggested to use random cost simulations for generating a set of selected configurations. On each of those final minimization may then be performed by a standard algorithm. For the training example at hand many almost degenerate local minima are thus found. Some effort is spend to discuss whether they lead to equivalent classifications of the data.
1604.03017
Stefano Frixione
Rikkert Frederix, Stefano Frixione, Eleni Vryonidou, Marius Wiesemann
Heavy-quark mass effects in Higgs plus jets production
22 pages, 7 figures; 4 references and some clarifications added to the text
null
10.1007/JHEP08(2016)006
CP3-16-11, MCNET-16-10, TUM-HEP-1040/16, ZU-TH-10/16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production of a Standard Model Higgs boson in the gluon-fusion channel at the 13 TeV LHC. Our results are accurate to the next-to-leading order in QCD, bar for the lack of some two-loop amplitudes, for up to two extra jets and are matched to the PYTHIA8 Monte Carlo. We address the impact, at the level of inclusive rates and of differential distributions, of the merging of samples characterised by different final-state multiplicities, and of the effects induced by top and bottom masses through heavy-quark loop diagrams. We find that both the merging and the heavy-quark masses must be included in the calculation in order to realistically predict observables of experimental interest.
[ { "created": "Mon, 11 Apr 2016 16:14:19 GMT", "version": "v1" }, { "created": "Mon, 1 Aug 2016 09:49:17 GMT", "version": "v2" } ]
2016-08-24
[ [ "Frederix", "Rikkert", "" ], [ "Frixione", "Stefano", "" ], [ "Vryonidou", "Eleni", "" ], [ "Wiesemann", "Marius", "" ] ]
We study the production of a Standard Model Higgs boson in the gluon-fusion channel at the 13 TeV LHC. Our results are accurate to the next-to-leading order in QCD, bar for the lack of some two-loop amplitudes, for up to two extra jets and are matched to the PYTHIA8 Monte Carlo. We address the impact, at the level of inclusive rates and of differential distributions, of the merging of samples characterised by different final-state multiplicities, and of the effects induced by top and bottom masses through heavy-quark loop diagrams. We find that both the merging and the heavy-quark masses must be included in the calculation in order to realistically predict observables of experimental interest.
hep-ph/9708430
Fernando Monti Steffens
F.M.Steffens (Uni. of Sao Paulo)
Heavy Quarks in Polarized Structure Functions
Revised version which appeared in Nucl. Phys. B523 (1998) 487
Nucl.Phys.B523:487-500,1998
10.1016/S0550-3213(98)00114-X
null
hep-ph
null
Quark mass effects are included in the calculation of polarized structure functions. In particular, the validity of fixed order perturbation theory and of massless evolution is studied in the framework of heavy quarks structure functions. The polarized version of the ACOT and MRRS interpolating schemes for the evolution of massive quarks distributions is also developed and studied. The different behaviours of the various approaches in $x$ and $Q^2$ are shown.
[ { "created": "Thu, 21 Aug 1997 20:33:11 GMT", "version": "v1" }, { "created": "Tue, 6 Oct 1998 16:04:14 GMT", "version": "v2" } ]
2014-11-17
[ [ "Steffens", "F. M.", "", "Uni. of Sao Paulo" ] ]
Quark mass effects are included in the calculation of polarized structure functions. In particular, the validity of fixed order perturbation theory and of massless evolution is studied in the framework of heavy quarks structure functions. The polarized version of the ACOT and MRRS interpolating schemes for the evolution of massive quarks distributions is also developed and studied. The different behaviours of the various approaches in $x$ and $Q^2$ are shown.
1605.09028
Anton Rebhan
A. Rebhan
Scalar and tensor glueball decay rates from the Witten-Sakai-Sugimoto model
5 pages, to appear in the proceedings of the 51st Rencontres de Moriond - QCD and High Energy Interactions
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The holographic Witten-Sakai-Sugimoto model is an almost parameter-free approximation to large-N QCD with chiral quarks that in a number of cases gives surprisingly good quantitative results for light meson physics. It also allows for predictions of the decay rates of glueballs into pseudoscalar and vector mesons through the coupling of modes on the flavor branes to the massive gravitational modes in the bulk. Including effects from finite quark masses leads to an enhancement of the decay of scalar glueballs into heavier pseudoscalars in good agreement with the decay pattern observed for the scalar glueball candidate f0(1710). Tensor glueballs are found to have a large width when their masses are above the 2 rho and 2 K* thresholds. With a mass as suggested by lattice gauge theory the lowest tensor glueball appears to be too broad to be observable, in contrast to the pseudoscalar glueball which may be a rather narrow state.
[ { "created": "Sun, 29 May 2016 16:53:56 GMT", "version": "v1" } ]
2016-05-31
[ [ "Rebhan", "A.", "" ] ]
The holographic Witten-Sakai-Sugimoto model is an almost parameter-free approximation to large-N QCD with chiral quarks that in a number of cases gives surprisingly good quantitative results for light meson physics. It also allows for predictions of the decay rates of glueballs into pseudoscalar and vector mesons through the coupling of modes on the flavor branes to the massive gravitational modes in the bulk. Including effects from finite quark masses leads to an enhancement of the decay of scalar glueballs into heavier pseudoscalars in good agreement with the decay pattern observed for the scalar glueball candidate f0(1710). Tensor glueballs are found to have a large width when their masses are above the 2 rho and 2 K* thresholds. With a mass as suggested by lattice gauge theory the lowest tensor glueball appears to be too broad to be observable, in contrast to the pseudoscalar glueball which may be a rather narrow state.
0804.2676
Michael Rauch
W. Hollik, T. Plehn, M. Rauch, H. Rzehak
Supersymmetric Higgs Bosons in Weak Boson Fusion
5 pages, 2 figures
Phys.Rev.Lett.102:091802,2009
10.1103/PhysRevLett.102.091802
Edinburgh 2008/16, PSI-PR-08-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the complete supersymmetric next-to-leading order corrections to the production of a light Higgs boson in weak boson fusion. The size of the electroweak corrections is of similar order as the next-to-leading order corrections in the Standard Model. The supersymmetric QCD corrections turn out to be significantly smaller than their electroweak counterparts. These higher--order corrections are an important ingredient to a precision analysis of the (supersymmetric) Higgs sector at the LHC, either as a known correction factor or as a contribution to the theory error.
[ { "created": "Thu, 17 Apr 2008 18:04:54 GMT", "version": "v1" } ]
2009-04-08
[ [ "Hollik", "W.", "" ], [ "Plehn", "T.", "" ], [ "Rauch", "M.", "" ], [ "Rzehak", "H.", "" ] ]
We compute the complete supersymmetric next-to-leading order corrections to the production of a light Higgs boson in weak boson fusion. The size of the electroweak corrections is of similar order as the next-to-leading order corrections in the Standard Model. The supersymmetric QCD corrections turn out to be significantly smaller than their electroweak counterparts. These higher--order corrections are an important ingredient to a precision analysis of the (supersymmetric) Higgs sector at the LHC, either as a known correction factor or as a contribution to the theory error.
1908.10105
Siamak Sadat Gousheh
S. Abbaslu, S. Rostam Zadeh and S. S. Gousheh
Contribution of the chiral vortical effect to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the early Universe
28 pages, 2 figures
Phys. Rev. D 100, 116022 (2019)
10.1103/PhysRevD.100.116022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the contribution of the chiral vortical effect, in addition to that of the chiral magnetic effect, to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the symmetric phase of the early Universe in the temperature range 100GeV < T < 10TeV. We choose a fully helical Chern-Simons wave configuration for the velocity and the hypermagnetic vector potential fields. The latter makes the plasma force-free in the absence of viscosity. We show that the most pronounced effect of the chiral vorticity is the production and initial growth of the hypermagnetic field. In particular, we show that in the presence of a non-zero matter asymmetry, the hypermagnetic field can grow from zero initial value only in the presence of a non-zero vorticity field. Moreover, we show that larger initial growths not only result in larger maximum values of the hypermagnetic field, but also cause the saturation of the hypermagnetic field and the conversion of the lepton-baryon asymmetry to occur more quickly, i.e., at a higher temperature. We show that the damping of the vorticity due to the presence of viscosity, which typically occurs extremely rapidly, does not significantly affect the evolution.
[ { "created": "Tue, 27 Aug 2019 09:39:33 GMT", "version": "v1" }, { "created": "Fri, 10 Jan 2020 15:43:54 GMT", "version": "v2" } ]
2020-01-13
[ [ "Abbaslu", "S.", "" ], [ "Zadeh", "S. Rostam", "" ], [ "Gousheh", "S. S.", "" ] ]
In this paper, we study the contribution of the chiral vortical effect, in addition to that of the chiral magnetic effect, to the evolution of the hypermagnetic field and the matter-antimatter asymmetry in the symmetric phase of the early Universe in the temperature range 100GeV < T < 10TeV. We choose a fully helical Chern-Simons wave configuration for the velocity and the hypermagnetic vector potential fields. The latter makes the plasma force-free in the absence of viscosity. We show that the most pronounced effect of the chiral vorticity is the production and initial growth of the hypermagnetic field. In particular, we show that in the presence of a non-zero matter asymmetry, the hypermagnetic field can grow from zero initial value only in the presence of a non-zero vorticity field. Moreover, we show that larger initial growths not only result in larger maximum values of the hypermagnetic field, but also cause the saturation of the hypermagnetic field and the conversion of the lepton-baryon asymmetry to occur more quickly, i.e., at a higher temperature. We show that the damping of the vorticity due to the presence of viscosity, which typically occurs extremely rapidly, does not significantly affect the evolution.
1503.05923
Zhen Liu
Zhen Liu, Brock Tweedie
The Fate of Long-Lived Superparticles with Hadronic Decays after LHC Run 1
36 pages, 10 figures, plus appendix and references
JHEP06(2015)042
10.1007/JHEP06(2015)042
PITT PACC 1503, FERMILAB-PUB-15-087-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation, and mini-split SUSY. We explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final-state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMS's tracker-based displaced dijet search and heavy stable charged particle searches. Adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.
[ { "created": "Thu, 19 Mar 2015 20:00:24 GMT", "version": "v1" } ]
2015-06-15
[ [ "Liu", "Zhen", "" ], [ "Tweedie", "Brock", "" ] ]
Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation, and mini-split SUSY. We explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final-state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMS's tracker-based displaced dijet search and heavy stable charged particle searches. Adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.
2108.04955
Nikita Larin
Sergei P. Roshchupkin, Nikita R. Larin and Victor V. Dubov
Resonant photoproduction of ultrarelativistic electron-positron pairs on a nucleus in strong monochromatic light field
null
null
10.1103/PhysRevD.104.116011
null
hep-ph physics.atom-ph
http://creativecommons.org/licenses/by/4.0/
For complete development of quantum electrodynamics in the presence of a strong external field, the proper understanding of resonant processes and all their peculiarities is essential. We present our attempt to analytically investigate the resonant case of laser-assisted electron-positron pair photoproduction on a nucleus. Due to the presence of external field, the intermediate virtual particle may become real, herewith the second order process in the fine structure constant effectively reduces into the two successive first order processes. All inherent kinematics features were discussed in details and the resonant differential cross section was obtained. We established that the resonant energies of produced particles ambiguously depend on the positron (channel A) or electron (channel B) outgoing angle, and the certain minimal amount of absorbed wave photons are required for resonance to happen. Furthermore, the resonant cross section significantly exceeds the corresponding one in the absence of the external field within the particular kinematic regions and consequently, the considered process can be used qua a marker for probing theoretical predictions of quantum electrodynamics with strong background field.
[ { "created": "Tue, 10 Aug 2021 22:45:41 GMT", "version": "v1" } ]
2022-01-05
[ [ "Roshchupkin", "Sergei P.", "" ], [ "Larin", "Nikita R.", "" ], [ "Dubov", "Victor V.", "" ] ]
For complete development of quantum electrodynamics in the presence of a strong external field, the proper understanding of resonant processes and all their peculiarities is essential. We present our attempt to analytically investigate the resonant case of laser-assisted electron-positron pair photoproduction on a nucleus. Due to the presence of external field, the intermediate virtual particle may become real, herewith the second order process in the fine structure constant effectively reduces into the two successive first order processes. All inherent kinematics features were discussed in details and the resonant differential cross section was obtained. We established that the resonant energies of produced particles ambiguously depend on the positron (channel A) or electron (channel B) outgoing angle, and the certain minimal amount of absorbed wave photons are required for resonance to happen. Furthermore, the resonant cross section significantly exceeds the corresponding one in the absence of the external field within the particular kinematic regions and consequently, the considered process can be used qua a marker for probing theoretical predictions of quantum electrodynamics with strong background field.
hep-ph/9410336
null
W. Grimus and H. Neufeld
Neutrinos interacting with Polarizable Media
9 pages, UWThPh-1994-41
null
null
null
hep-ph
null
We study Cherenkov and transition radiation of neutral spin 1/2 particles which carry magnetic moments or electric dipole moments. In particular, we estimate the radiation caused by the solar neutrino flux in dielectric media.
[ { "created": "Thu, 20 Oct 1994 17:58:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grimus", "W.", "" ], [ "Neufeld", "H.", "" ] ]
We study Cherenkov and transition radiation of neutral spin 1/2 particles which carry magnetic moments or electric dipole moments. In particular, we estimate the radiation caused by the solar neutrino flux in dielectric media.
1307.5458
Julien Billard
J. Billard (1), L. Strigari (2), E. Figueroa-Feliciano (1) ((1) MIT, (2) KIPAC/Stanford)
Implication of neutrino backgrounds on the reach of next generation dark matter direct detection experiments
15 pages, 12 figures, 7Be fluxes revised, conclusions unchanged
Phys. Rev. D 89, 023524 (2014)
10.1103/PhysRevD.89.023524
null
hep-ph astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As direct dark matter experiments continue to increase in size, they will become sensitive to neutrinos from astrophysical sources. For experiments that do not have directional sensitivity, coherent neutrino scattering (CNS) from several sources represents an important background to understand, as it can almost perfectly mimic an authentic WIMP signal. Here we explore in detail the effect of neutrino backgrounds on the discovery potential of WIMPs over the entire mass range of 500 MeV to 10 TeV. We show that, given the theoretical and measured uncertainties on the neutrino backgrounds, direct detection experiments lose sensitivity to light (~10 GeV) and heavy (~100 GeV) WIMPs with a spin-independent cross section below 10^{-45} cm^2 and 10^{-49} cm^2, respectively.
[ { "created": "Sat, 20 Jul 2013 20:16:11 GMT", "version": "v1" }, { "created": "Sun, 11 Aug 2013 15:59:55 GMT", "version": "v2" }, { "created": "Sun, 19 Jan 2014 18:10:55 GMT", "version": "v3" } ]
2015-06-16
[ [ "Billard", "J.", "" ], [ "Strigari", "L.", "" ], [ "Figueroa-Feliciano", "E.", "" ] ]
As direct dark matter experiments continue to increase in size, they will become sensitive to neutrinos from astrophysical sources. For experiments that do not have directional sensitivity, coherent neutrino scattering (CNS) from several sources represents an important background to understand, as it can almost perfectly mimic an authentic WIMP signal. Here we explore in detail the effect of neutrino backgrounds on the discovery potential of WIMPs over the entire mass range of 500 MeV to 10 TeV. We show that, given the theoretical and measured uncertainties on the neutrino backgrounds, direct detection experiments lose sensitivity to light (~10 GeV) and heavy (~100 GeV) WIMPs with a spin-independent cross section below 10^{-45} cm^2 and 10^{-49} cm^2, respectively.
hep-ph/9905202
Zurab Tavartkiladze
Qaisar Shafi and Zurab Tavartkiladze
Proton Decay, Neutrino Oscillations And Other Consequences From Supersymmetric SU(6) With Pseudo-Goldstone Higgs
20 pp. LATEX. Version with minor corrections accepted for Nucl. Phys. B
Nucl.Phys.B573:40-56,2000
10.1016/S0550-3213(99)00606-9
BA-99-39
hep-ph
null
We suggest a new mechanism for naturally suppressing dimension five baryon number violating in supersymmetric SU(5+N) (N=0, 1,...) GUTs. The mechanism is realized through suppression of qqT type couplings, and is implemented by introducing new `matter' multiplets belonging to symmetric representations of SU(5+N). Together with the suppression of nucleon decay, these multiplets also enable one to avoid the unwanted asymptotic mass relations $m_s=m_{\mu}$, $\frac{m_d}{m_s}=\frac{m_e}{m_{\mu}}$. As an example, we consider a SU(6) model with pseudo-Goldstone Higgs. By supplementing the model with an anomalous ${\cal U}(1)$ flavor symmetry, we also obtain a simple `all-order' solution of the gauge hierarchy problem and natural explanation of charged fermion mass hierarchies and values of the CKM matrix elements. The proton life time $\tau_p\sim 10^{2}\tau_p^{SU(5)}$~yr. is compatible with experiments, with the dominant decay being $p\to K\nu_{\mu, \tau}$. Thanks to the SU(6) symmetry, successful unification of the gauge couplings can be retained, and the value of the strong coupling $\alpha_s(M_Z)$ can be reduced to $\simeq 0.12$. Finally, we show how to accommodate the solar and atmospheric neutrino data through the bi-maximal neutrino mixing scenario, with maximal vacuum $\nu_e-\nu_{\mu, \tau}$ and large angle $\nu_{\mu}-\nu_{\tau}$ oscillations.
[ { "created": "Sat, 1 May 1999 18:42:15 GMT", "version": "v1" }, { "created": "Sat, 18 Sep 1999 09:09:06 GMT", "version": "v2" } ]
2011-05-12
[ [ "Shafi", "Qaisar", "" ], [ "Tavartkiladze", "Zurab", "" ] ]
We suggest a new mechanism for naturally suppressing dimension five baryon number violating in supersymmetric SU(5+N) (N=0, 1,...) GUTs. The mechanism is realized through suppression of qqT type couplings, and is implemented by introducing new `matter' multiplets belonging to symmetric representations of SU(5+N). Together with the suppression of nucleon decay, these multiplets also enable one to avoid the unwanted asymptotic mass relations $m_s=m_{\mu}$, $\frac{m_d}{m_s}=\frac{m_e}{m_{\mu}}$. As an example, we consider a SU(6) model with pseudo-Goldstone Higgs. By supplementing the model with an anomalous ${\cal U}(1)$ flavor symmetry, we also obtain a simple `all-order' solution of the gauge hierarchy problem and natural explanation of charged fermion mass hierarchies and values of the CKM matrix elements. The proton life time $\tau_p\sim 10^{2}\tau_p^{SU(5)}$~yr. is compatible with experiments, with the dominant decay being $p\to K\nu_{\mu, \tau}$. Thanks to the SU(6) symmetry, successful unification of the gauge couplings can be retained, and the value of the strong coupling $\alpha_s(M_Z)$ can be reduced to $\simeq 0.12$. Finally, we show how to accommodate the solar and atmospheric neutrino data through the bi-maximal neutrino mixing scenario, with maximal vacuum $\nu_e-\nu_{\mu, \tau}$ and large angle $\nu_{\mu}-\nu_{\tau}$ oscillations.
1712.02659
Georg Wolschin
Georg Wolschin
Equilibration in finite Bose systems
26 pages, 7 figures
Physica A 499, 1 (2018)
10.1016/j.physa.2018.01.035
null
hep-ph math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The equilibration of a finite Bose system is modelled using a gradient expansion of the collision integral that leads to a nonlinear transport equation. For constant transport coefficients, it is solved in closed form through a nonlinear transformation. Using schematic initial conditions, the exact solution and the equilibration time are derived and compared to the corresponding case for fermions. Applications to the equilibration of the gluon system created initially in relativistic heavy-ion collisions, and to cold quantum gases are envisaged.
[ { "created": "Thu, 7 Dec 2017 15:00:54 GMT", "version": "v1" }, { "created": "Thu, 8 Feb 2018 08:09:15 GMT", "version": "v2" } ]
2018-02-12
[ [ "Wolschin", "Georg", "" ] ]
The equilibration of a finite Bose system is modelled using a gradient expansion of the collision integral that leads to a nonlinear transport equation. For constant transport coefficients, it is solved in closed form through a nonlinear transformation. Using schematic initial conditions, the exact solution and the equilibration time are derived and compared to the corresponding case for fermions. Applications to the equilibration of the gluon system created initially in relativistic heavy-ion collisions, and to cold quantum gases are envisaged.
1701.04953
Kouji Kashiwa
Kouji Kashiwa, Akira Ohnishi
Topological deconfinement transition in QCD at finite isospin density
7 pages, 5 figures
Phys.Lett.B772:669-674,2017
10.1016/j.physletb.2017.07.033
YITP-17-04
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The confinement-deconfinement transition is discussed from topological viewpoints. The topological change of the system is achieved by introducing the dimensionless imaginary chemical potential ($\theta$). Then, the non-trivial free-energy degeneracy becomes the signal of the deconfinement transition and it can be visualized by using the map of the thermodynamic quantities to the circle $S^1$ along $\theta$. To understand this "topological" deconfinement transition at finite real quark chemical potential ($\mu_\mathrm{R}$), we consider the isospin chemical potential ($\mu_\mathrm{iso}$) in the effective model of QCD. The phase diagram at finite $\mu_\mathrm{iso}$ is identical with that at finite $\mu_\mathrm{R}$ outside of the pion-condensed phase at least in the large-$N_\mathrm{c}$ limit via the well-known orbifold equivalence. In the present effective model, the topological deconfinement transition does not show a significant dependence on $\mu_\mathrm{iso}$ and then we can expect that this tendency also appears at small $\mu_\mathrm{R}$. Also, the chiral transition and the topological deconfinement transition seems to be weakly correlated. If we will access lattice QCD data for the temperature dependence of the quark number density at finite $\mu_\mathrm{iso}$ with $\theta=\pi/3$, our surmise can be judged.
[ { "created": "Wed, 18 Jan 2017 05:41:36 GMT", "version": "v1" }, { "created": "Thu, 11 May 2017 01:54:27 GMT", "version": "v2" }, { "created": "Wed, 16 Aug 2017 08:35:09 GMT", "version": "v3" } ]
2017-08-17
[ [ "Kashiwa", "Kouji", "" ], [ "Ohnishi", "Akira", "" ] ]
The confinement-deconfinement transition is discussed from topological viewpoints. The topological change of the system is achieved by introducing the dimensionless imaginary chemical potential ($\theta$). Then, the non-trivial free-energy degeneracy becomes the signal of the deconfinement transition and it can be visualized by using the map of the thermodynamic quantities to the circle $S^1$ along $\theta$. To understand this "topological" deconfinement transition at finite real quark chemical potential ($\mu_\mathrm{R}$), we consider the isospin chemical potential ($\mu_\mathrm{iso}$) in the effective model of QCD. The phase diagram at finite $\mu_\mathrm{iso}$ is identical with that at finite $\mu_\mathrm{R}$ outside of the pion-condensed phase at least in the large-$N_\mathrm{c}$ limit via the well-known orbifold equivalence. In the present effective model, the topological deconfinement transition does not show a significant dependence on $\mu_\mathrm{iso}$ and then we can expect that this tendency also appears at small $\mu_\mathrm{R}$. Also, the chiral transition and the topological deconfinement transition seems to be weakly correlated. If we will access lattice QCD data for the temperature dependence of the quark number density at finite $\mu_\mathrm{iso}$ with $\theta=\pi/3$, our surmise can be judged.
1604.07896
Masaki J.S. Yang
Masaki J. S. Yang
Hierarchical majorana neutrinos from democratic mass matrices
14 pages, 1 table, substantially revised version
Phys.Lett.B 760 (2016) 747-752
10.1016/j.physletb.2016.06.079
STUPP-16-227
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we obtain the light neutrino masses and mixings consistent with the experiments, in the democratic texture approach. The essential ansatz is that $\nu_{Ri}$ are assumed to transform as "right-handed fields" $\bf 2_{R} + 1_{R}$ under the $S_{3L} \times S_{3R}$ symmetry. The symmetry breaking terms are assumed to be diagonal and hierarchical. This setup only allows the normal hierarchy of the neutrino mass, and excludes both of inverted hierarchical and degenerated neutrinos. Although the neutrino sector has nine free parameters, several predictions are obtained at the leading order. When we neglect the smallest parameters $\zeta_{\nu}$ and $\zeta_{R}$, all components of the mixing matrix $U_{\rm PMNS}$ are expressed by the masses of light neutrinos and charged leptons. From the consistency between predicted and observed $U_{\rm PMNS}$, we obtain the lightest neutrino masses $m_{1}$ = (1.1 $\to$ 1.4) meV, and the effective mass for the double beta decay $\vev{m_{ee}} \simeq$ 4.5 meV.
[ { "created": "Wed, 27 Apr 2016 00:51:18 GMT", "version": "v1" }, { "created": "Wed, 29 Jun 2016 01:18:33 GMT", "version": "v2" } ]
2020-05-28
[ [ "Yang", "Masaki J. S.", "" ] ]
In this paper, we obtain the light neutrino masses and mixings consistent with the experiments, in the democratic texture approach. The essential ansatz is that $\nu_{Ri}$ are assumed to transform as "right-handed fields" $\bf 2_{R} + 1_{R}$ under the $S_{3L} \times S_{3R}$ symmetry. The symmetry breaking terms are assumed to be diagonal and hierarchical. This setup only allows the normal hierarchy of the neutrino mass, and excludes both of inverted hierarchical and degenerated neutrinos. Although the neutrino sector has nine free parameters, several predictions are obtained at the leading order. When we neglect the smallest parameters $\zeta_{\nu}$ and $\zeta_{R}$, all components of the mixing matrix $U_{\rm PMNS}$ are expressed by the masses of light neutrinos and charged leptons. From the consistency between predicted and observed $U_{\rm PMNS}$, we obtain the lightest neutrino masses $m_{1}$ = (1.1 $\to$ 1.4) meV, and the effective mass for the double beta decay $\vev{m_{ee}} \simeq$ 4.5 meV.
2004.00631
Joel Doss
Timothy Cohen, Joel Doss, Marat Freytsis
Jet Substructure from Dark Sector Showers
30 pages + appendix, 11 figures; v3: minor clarifications added
null
10.1007/JHEP09(2020)118
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the robustness of collider phenomenology predictions for a dark sector scenario with QCD-like properties. Pair production of dark quarks at the LHC can result in a wide variety of signatures, depending on the details of the new physics model. A particularly challenging signal results when prompt production induces a parton shower that yields a high multiplicity of collimated dark hadrons with subsequent decays to Standard Model hadrons. The final states contain jets whose substructure encodes their non-QCD origin. This is a relatively subtle signature of strongly coupled beyond the Standard Model dynamics, and thus it is crucial that analyses incorporate systematic errors to account for the approximations that are being made when modeling the signal. We estimate theoretical uncertainties for a canonical substructure observable designed to be sensitive to the gauge structure of the underlying object, the two-point energy correlator $e_2^{(\beta)}$, by computing envelopes between resummed analytic distributions and numerical results from Pythia. We explore the separability against the QCD background as the confinement scale, number of colors, number of flavors, and dark quark masses are varied. Additionally, we investigate the uncertainties inherent to modeling dark sector hadronization. Simple estimates are provided that quantify one's ability to distinguish these dark sector jets from the overwhelming QCD background. Such a search would benefit from theory advances to improve the predictions, and the increase in statistics using the data to be collected at the high luminosity LHC.
[ { "created": "Wed, 1 Apr 2020 18:00:01 GMT", "version": "v1" }, { "created": "Mon, 21 Dec 2020 15:56:05 GMT", "version": "v2" }, { "created": "Mon, 6 Jun 2022 18:46:13 GMT", "version": "v3" } ]
2022-06-08
[ [ "Cohen", "Timothy", "" ], [ "Doss", "Joel", "" ], [ "Freytsis", "Marat", "" ] ]
We examine the robustness of collider phenomenology predictions for a dark sector scenario with QCD-like properties. Pair production of dark quarks at the LHC can result in a wide variety of signatures, depending on the details of the new physics model. A particularly challenging signal results when prompt production induces a parton shower that yields a high multiplicity of collimated dark hadrons with subsequent decays to Standard Model hadrons. The final states contain jets whose substructure encodes their non-QCD origin. This is a relatively subtle signature of strongly coupled beyond the Standard Model dynamics, and thus it is crucial that analyses incorporate systematic errors to account for the approximations that are being made when modeling the signal. We estimate theoretical uncertainties for a canonical substructure observable designed to be sensitive to the gauge structure of the underlying object, the two-point energy correlator $e_2^{(\beta)}$, by computing envelopes between resummed analytic distributions and numerical results from Pythia. We explore the separability against the QCD background as the confinement scale, number of colors, number of flavors, and dark quark masses are varied. Additionally, we investigate the uncertainties inherent to modeling dark sector hadronization. Simple estimates are provided that quantify one's ability to distinguish these dark sector jets from the overwhelming QCD background. Such a search would benefit from theory advances to improve the predictions, and the increase in statistics using the data to be collected at the high luminosity LHC.
1008.4641
Ken-iti Izawa
K.-I. Izawa, T. Kugo, T.T. Yanagida
Gravitational Supersymmetry Breaking
6 pages
Prog.Theor.Phys.125:261-264,2011
10.1143/PTP.125.261
YITP-10-73, IPMU 10-0143
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider supersymmetry breaking models with a purely constant superpotential in supergravity. The supersymmetry breaking is induced for the vanishing cosmological constant. As a hidden mediation sector of supersymmetry breaking, it naturally leads to a split spectrum in supersymmetric standard model. We also point out possible utility of our setup to construct nonlinear sigma model and/or Fayet-Iliopoulos-like term in broken supergravity.
[ { "created": "Fri, 27 Aug 2010 04:57:43 GMT", "version": "v1" } ]
2011-05-09
[ [ "Izawa", "K. -I.", "" ], [ "Kugo", "T.", "" ], [ "Yanagida", "T. T.", "" ] ]
We consider supersymmetry breaking models with a purely constant superpotential in supergravity. The supersymmetry breaking is induced for the vanishing cosmological constant. As a hidden mediation sector of supersymmetry breaking, it naturally leads to a split spectrum in supersymmetric standard model. We also point out possible utility of our setup to construct nonlinear sigma model and/or Fayet-Iliopoulos-like term in broken supergravity.
1311.3714
Xiao-Gang He
Dong Xu, Guan-Nan Li, Xiao-Gang He
U-spin analysis of CP violation in $B^- $ decays into three charged light pseudoscalar mesons
RevTex 12 pages wit no figure
null
10.1016/j.physletb.2013.12.040
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We carry out a $U$-spin symmetry analysis for CP violation in $B^- $ decays into three light $\pi^-\pi^-\pi^+$, $\pi^- K^-K^+$, $K^-K^-K^+$ and $K^- \pi^-\pi^+$ mesons. We clarify some subtle points in constructing decay amplitudes with $U=0$ formed by the two negatively charged light mesons in the final states. $U$-spin conserving momentum independent and momentum dependent decay amplitudes, and $U$-spin violating decay amplitudes due to quark mass difference are constructed.
[ { "created": "Fri, 15 Nov 2013 03:29:59 GMT", "version": "v1" } ]
2015-06-17
[ [ "Xu", "Dong", "" ], [ "Li", "Guan-Nan", "" ], [ "He", "Xiao-Gang", "" ] ]
We carry out a $U$-spin symmetry analysis for CP violation in $B^- $ decays into three light $\pi^-\pi^-\pi^+$, $\pi^- K^-K^+$, $K^-K^-K^+$ and $K^- \pi^-\pi^+$ mesons. We clarify some subtle points in constructing decay amplitudes with $U=0$ formed by the two negatively charged light mesons in the final states. $U$-spin conserving momentum independent and momentum dependent decay amplitudes, and $U$-spin violating decay amplitudes due to quark mass difference are constructed.
hep-ph/9902362
Emidio Gabrielli
E. Gabrielli, V.A. Ilyin and B. Mele
Looking for anomalous gamma-gamma-H and Z-gamma-H couplings at future linear collider
LaTeX, 33 pages, 16 eps figures, extended section 5
Phys.Rev.D60:113005,1999
10.1103/PhysRevD.60.113005
ROME1-1235/99
hep-ph
null
We consider the possibility of studying anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices through the process e-gamma--> e-H at future e-gamma linear colliders, with Sqrt(S)=500-1500 GeV. We make a model independent analysis based on SU(2)xU(1) invariant effective operators of dim=6 added to the standard model lagrangian. We consider a light Higgs boson (mostly decaying in bar(b)-b pairs), and include all the relevant backgrounds. Initial e-beam polarization effects are also analyzed. We find that the process e-gamma--> e-H provides an excellent opportunity to strongly constrain both the CP-even and the CP-odd anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices.
[ { "created": "Tue, 16 Feb 1999 15:06:00 GMT", "version": "v1" }, { "created": "Wed, 1 Dec 1999 12:35:47 GMT", "version": "v2" } ]
2011-07-19
[ [ "Gabrielli", "E.", "" ], [ "Ilyin", "V. A.", "" ], [ "Mele", "B.", "" ] ]
We consider the possibility of studying anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices through the process e-gamma--> e-H at future e-gamma linear colliders, with Sqrt(S)=500-1500 GeV. We make a model independent analysis based on SU(2)xU(1) invariant effective operators of dim=6 added to the standard model lagrangian. We consider a light Higgs boson (mostly decaying in bar(b)-b pairs), and include all the relevant backgrounds. Initial e-beam polarization effects are also analyzed. We find that the process e-gamma--> e-H provides an excellent opportunity to strongly constrain both the CP-even and the CP-odd anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices.
1507.01409
Ajay Kumar Rai
Ajay Kumar Rai and D. P. Rathaud
The mass spectra and decay properties of dimesonic states, using the Hellmann potential
11 pages, 4 tables
Eur. Phys. J. C 75 (2015) 9, 462
10.1140/epjc/s10052-015-3695-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mass spectra of the dimesonic (meson-antimeson) molecular states are computed using the Hellmann potential in variational approach, which consists of relativistic correction to kinetic energy term as well as to the potential energy term. For the study of molecular bound state system, the Hellmann potential of the form $V(r)=-\frac{\alpha_{s}}{r} + \frac{B e^{-Cr}}{r}$ is being used. The one pion exchange potential (OPEP) is also incorporated in the mass calculation. The digamma decay width and decay width of the dimesonic system are evaluated using the wave function. The experimental states such as $f_{0}(980)$, $b_{1}(1235)$, $h_{1}(1380)$, $a_{0}(1450)$, $f_{0}(1500)$, $f_{2}'(1525)$,$f_{2}(1565)$, $h_{1}(1595)$, $a_{2}(1700)$, $f_{0}(1710)$, $f_{2}(1810)$ are compared with dimesonic states. Many of these states (masses and their decay properties) are close to our theoretical predictions.
[ { "created": "Mon, 6 Jul 2015 12:13:57 GMT", "version": "v1" }, { "created": "Tue, 22 Sep 2015 09:52:19 GMT", "version": "v2" } ]
2015-10-14
[ [ "Rai", "Ajay Kumar", "" ], [ "Rathaud", "D. P.", "" ] ]
Mass spectra of the dimesonic (meson-antimeson) molecular states are computed using the Hellmann potential in variational approach, which consists of relativistic correction to kinetic energy term as well as to the potential energy term. For the study of molecular bound state system, the Hellmann potential of the form $V(r)=-\frac{\alpha_{s}}{r} + \frac{B e^{-Cr}}{r}$ is being used. The one pion exchange potential (OPEP) is also incorporated in the mass calculation. The digamma decay width and decay width of the dimesonic system are evaluated using the wave function. The experimental states such as $f_{0}(980)$, $b_{1}(1235)$, $h_{1}(1380)$, $a_{0}(1450)$, $f_{0}(1500)$, $f_{2}'(1525)$,$f_{2}(1565)$, $h_{1}(1595)$, $a_{2}(1700)$, $f_{0}(1710)$, $f_{2}(1810)$ are compared with dimesonic states. Many of these states (masses and their decay properties) are close to our theoretical predictions.
0909.2199
Enrico Scomparin
R.Arnaldi, P.Cortese and E. Scomparin
Role of parton shadowing in the comparison of p-A and A-A results on jpsi suppression at energies available at the CERN Super Proton Synchrotron
6 pages, 6 figures, final version published in Phys. Rev. C 81 (2010) 014903
Phys.Rev.C81:014903,2010
10.1103/PhysRevC.81.014903
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observation of an anomalous jpsi suppression in nucleus-nucleus collisions is one of the most important results of the SPS heavy-ion program. An essential ingredient in this result is the determination, obtained by studying p-A collisions, of effects not related with the formation of a deconfined medium. These effects are extrapolated to A-A collisions, determining a reference jpsi yield that is then compared with the measurements. In this article we investigate the role of parton shadowing on the determination of such a reference, and we calculate its effect for In-In and Pb-Pb collisions as a function of rapidity and centrality.
[ { "created": "Fri, 11 Sep 2009 15:42:16 GMT", "version": "v1" }, { "created": "Tue, 22 Sep 2009 10:03:34 GMT", "version": "v2" }, { "created": "Thu, 14 Jan 2010 09:51:24 GMT", "version": "v3" } ]
2010-04-06
[ [ "Arnaldi", "R.", "" ], [ "Cortese", "P.", "" ], [ "Scomparin", "E.", "" ] ]
The observation of an anomalous jpsi suppression in nucleus-nucleus collisions is one of the most important results of the SPS heavy-ion program. An essential ingredient in this result is the determination, obtained by studying p-A collisions, of effects not related with the formation of a deconfined medium. These effects are extrapolated to A-A collisions, determining a reference jpsi yield that is then compared with the measurements. In this article we investigate the role of parton shadowing on the determination of such a reference, and we calculate its effect for In-In and Pb-Pb collisions as a function of rapidity and centrality.
1411.2786
Farvah Mahmoudi
T. Hurth, F. Mahmoudi
Signs for new physics in the recent LHCb data?
6 pages, 6 figures. Based on talks given at the Fifth Workshop on Theory, Phenomenology and Experiments in Flavour Physics, Capri, 23-25 May 2014 and at the FPCP 2014 conference on Flavor Physics and CP Violation, Marseille, 25-30 May 2014
null
null
CERN-PH-TH/2014-212, MITP/14-087
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We comment on some tensions with the Standard Model predictions in the recent LHCb data.
[ { "created": "Tue, 11 Nov 2014 12:54:08 GMT", "version": "v1" } ]
2014-11-12
[ [ "Hurth", "T.", "" ], [ "Mahmoudi", "F.", "" ] ]
We comment on some tensions with the Standard Model predictions in the recent LHCb data.
2211.14792
Qi Zhou
Qi Zhou and Ben-Wei Zhang
Holographic energy loss near critical temperature in an anisotropic background
10 pages,5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the energy loss of a quark moving in a strongly coupled QGP under the influence of anisotropy. The heavy quark drag force, diffusion coefficient, and jet quenching parameter are calculated using the Einstein-Maxwell-dilaton model, where the anisotropic background is characterized by an arbitrary dynamical parameter $A$.Our findings indicate that as the anisotropic factor $A$ increases, the drag force and jet quenching parameter both increase, while the diffusion coefficient decreases. Additionally, we observe that the energy loss becomes more significant when the quark moves perpendicular to the anisotropy direction in the transverse plane.The enhancement of the rescaled jet quenching parameters near critical temperature $T_c$, as well as drag forces for a fast-moving heavy quark is observed, which presents one of the typical features of QCD phase transition.
[ { "created": "Sun, 27 Nov 2022 11:14:34 GMT", "version": "v1" }, { "created": "Sun, 1 Jan 2023 03:34:59 GMT", "version": "v2" }, { "created": "Tue, 25 Jul 2023 07:54:10 GMT", "version": "v3" } ]
2023-07-26
[ [ "Zhou", "Qi", "" ], [ "Zhang", "Ben-Wei", "" ] ]
We study the energy loss of a quark moving in a strongly coupled QGP under the influence of anisotropy. The heavy quark drag force, diffusion coefficient, and jet quenching parameter are calculated using the Einstein-Maxwell-dilaton model, where the anisotropic background is characterized by an arbitrary dynamical parameter $A$.Our findings indicate that as the anisotropic factor $A$ increases, the drag force and jet quenching parameter both increase, while the diffusion coefficient decreases. Additionally, we observe that the energy loss becomes more significant when the quark moves perpendicular to the anisotropy direction in the transverse plane.The enhancement of the rescaled jet quenching parameters near critical temperature $T_c$, as well as drag forces for a fast-moving heavy quark is observed, which presents one of the typical features of QCD phase transition.
hep-ph/9903342
Josephine Bolosan
S. F. Tuan (University of Hawaii)
Implications of a $\chi(3.86)$ State for Theoretical Models
7 pages, LATEX format, no figures, no tables
Phys.Lett. B473 (2000) 136-140
10.1016/S0370-2693(99)01428-8
UH511-909-98
hep-ph
null
Recent preliminary evidence for a $D \bar{D}$ state $\chi(3.86)$ raises extremely interesting implications for theoretical models, particularly those currently in vogue, e.g. the flux tube model and a molecular charmonium picture. We examine the experimental consequences as well as the possible unveiling of a strata of C-exotic states in heavy quarkonia systems by future facilities like BES Upgrade/Tau-Charm Factory and CLEO III/B-Factories.
[ { "created": "Fri, 12 Mar 1999 21:03:22 GMT", "version": "v1" } ]
2009-10-31
[ [ "Tuan", "S. F.", "", "University of Hawaii" ] ]
Recent preliminary evidence for a $D \bar{D}$ state $\chi(3.86)$ raises extremely interesting implications for theoretical models, particularly those currently in vogue, e.g. the flux tube model and a molecular charmonium picture. We examine the experimental consequences as well as the possible unveiling of a strata of C-exotic states in heavy quarkonia systems by future facilities like BES Upgrade/Tau-Charm Factory and CLEO III/B-Factories.
hep-ph/9511261
null
A.I. Davydychev and J.B. Tausk
Tensor reduction of two-loop vacuum diagrams and projectors for expanding three-point functions
13 pages, plain latex, no figures
Nucl.Phys. B465 (1996) 507-520
10.1016/0550-3213(96)00033-8
BERGEN-1995-14, MZ-TH-95-26
hep-ph hep-th
null
Explicit general formulae for the tensor reduction of two-loop massive vacuum diagrams are presented. The problem of calculating the corresponding coefficients is shown to be equivalent to the problem of constructing differential operators (projectors) extracting the coefficients of the momentum expansion of massive scalar three-point functions (with any number of loops), so the solution to the latter problem is also given.
[ { "created": "Tue, 7 Nov 1995 19:37:56 GMT", "version": "v1" } ]
2009-10-28
[ [ "Davydychev", "A. I.", "" ], [ "Tausk", "J. B.", "" ] ]
Explicit general formulae for the tensor reduction of two-loop massive vacuum diagrams are presented. The problem of calculating the corresponding coefficients is shown to be equivalent to the problem of constructing differential operators (projectors) extracting the coefficients of the momentum expansion of massive scalar three-point functions (with any number of loops), so the solution to the latter problem is also given.
hep-ph/0511064
Ulrich Baur
U. Baur
Electroweak Physics at the Tevatron and LHC: Theoretical Status and Perspectives
6 pages, 6 figures, to appear in the Proceedings of the HCP2005 Conference, Les Diablerets, Switzerland, 4-9 July 2005
null
null
null
hep-ph
null
I review the status of theoretical calculations relevant for electroweak physics at the Tevatron and LHC and discuss future directions. I also give a brief overview of current electroweak data and discuss future expectations.
[ { "created": "Mon, 7 Nov 2005 01:30:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baur", "U.", "" ] ]
I review the status of theoretical calculations relevant for electroweak physics at the Tevatron and LHC and discuss future directions. I also give a brief overview of current electroweak data and discuss future expectations.
hep-ph/0202067
Manfred Dillig
M. Dillig (Erlangen University)
Systematics of the Exclusive Meson Production in the Proton-Proton System in Relativistic Quark-Models
13 pages, 11 figures
null
null
FAU-TP3-02-02
hep-ph
null
We investigate the exclusive production of the pseudoscalar mesons pi0, eta, eta', K+ and of the vector mesons omega, phi in a microscopic gluon-exchange or instanton model. We describe the baryons as covariant quark - scalar diquark systems with harmonic confinement, thus taking into account center-of-mass corrections and Lorentz contraction in different frames. The excitation of intermediate baryon resonances is accounted by colorless 2-gluon (soft Pomeron) exchange. We find that our model accounts for the systematics of the high precision data on exclusive meson production from various modern proton factories.
[ { "created": "Thu, 7 Feb 2002 14:45:23 GMT", "version": "v1" }, { "created": "Thu, 21 Feb 2002 17:55:10 GMT", "version": "v2" }, { "created": "Fri, 22 Feb 2002 14:15:02 GMT", "version": "v3" } ]
2009-09-29
[ [ "Dillig", "M.", "", "Erlangen University" ] ]
We investigate the exclusive production of the pseudoscalar mesons pi0, eta, eta', K+ and of the vector mesons omega, phi in a microscopic gluon-exchange or instanton model. We describe the baryons as covariant quark - scalar diquark systems with harmonic confinement, thus taking into account center-of-mass corrections and Lorentz contraction in different frames. The excitation of intermediate baryon resonances is accounted by colorless 2-gluon (soft Pomeron) exchange. We find that our model accounts for the systematics of the high precision data on exclusive meson production from various modern proton factories.
0811.3849
Vitaly Okorokov A
V.A. Okorokov
Slope analysis for elastic proton-proton and proton-antiproton scattering
The XIX International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and Quantum Chromodynamics", JINR, Dubna, Russia, September 29 to October 4, 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at intermediate square of momentum transfer in the main. Energy dependence of the elastic diffraction slope is approximated by various analytic functions in a model-independent fashion. The expanded standard logarithmic approximations allow to describe experimental slopes in all available energy range at qualitative level reasonably. Various fitting functions differ from each other both in low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering at NICA, RHIC and LHC energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions at intermediate square of momentum transfer. Difference of nuclear slopes for proton-antiproton and proton-proton scattering is investigated in wide momentum transfer range also.
[ { "created": "Mon, 24 Nov 2008 11:43:57 GMT", "version": "v1" }, { "created": "Wed, 3 Dec 2008 11:05:25 GMT", "version": "v2" } ]
2008-12-03
[ [ "Okorokov", "V. A.", "" ] ]
The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at intermediate square of momentum transfer in the main. Energy dependence of the elastic diffraction slope is approximated by various analytic functions in a model-independent fashion. The expanded standard logarithmic approximations allow to describe experimental slopes in all available energy range at qualitative level reasonably. Various fitting functions differ from each other both in low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering at NICA, RHIC and LHC energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions at intermediate square of momentum transfer. Difference of nuclear slopes for proton-antiproton and proton-proton scattering is investigated in wide momentum transfer range also.
hep-ph/9409403
null
Dean Lee
Mesons with a Light Quark-Antiquark Pair and the Bethe-Salpeter Equation
9 pages uuencoded, unix compressed Postscript, HUTP-94/A030
null
null
null
hep-ph
null
The light quark-antiquark scattering Green's function is considered near a meson resonance peak. The Bethe-Salpeter equation is used to write formal expressions for the resonance width/mass ratio. Arguments are made concerning to what extent this ratio can be calculated perturbatively, and an upper bound is placed on the growth of this ratio as a function of radial excitation. Certain mesons and their radial excitations are considered, as well as the more general issue of classifying mesons in the quark model.
[ { "created": "Sat, 24 Sep 1994 04:16:00 GMT", "version": "v1" }, { "created": "Sat, 24 Sep 1994 04:36:38 GMT", "version": "v2" } ]
2008-02-03
[ [ "Lee", "Dean", "" ] ]
The light quark-antiquark scattering Green's function is considered near a meson resonance peak. The Bethe-Salpeter equation is used to write formal expressions for the resonance width/mass ratio. Arguments are made concerning to what extent this ratio can be calculated perturbatively, and an upper bound is placed on the growth of this ratio as a function of radial excitation. Certain mesons and their radial excitations are considered, as well as the more general issue of classifying mesons in the quark model.
hep-ph/9810252
Tonguc Rador
Tonguc Rador
Lepton Number Violation in Top-Color Assisted Technicolor
10 pages, 2 figures, uses revtex
Phys. Rev. D 59, 095012 (1999)
10.1103/PhysRevD.59.095012
null
hep-ph
null
We calculate the rates for lepton number violating processes via the exchange of the Z' boson occuring in top-color assisted technicolor. The current experimental limits on muon electron conversion in Ti nuclei allow for a mass of the new gauge boson around 1 TeV and the magnitudes of the mixing angles turn out to lie roughly between the analogous elements of the CKM matrix and its square root.
[ { "created": "Mon, 5 Oct 1998 18:42:29 GMT", "version": "v1" } ]
2016-08-25
[ [ "Rador", "Tonguc", "" ] ]
We calculate the rates for lepton number violating processes via the exchange of the Z' boson occuring in top-color assisted technicolor. The current experimental limits on muon electron conversion in Ti nuclei allow for a mass of the new gauge boson around 1 TeV and the magnitudes of the mixing angles turn out to lie roughly between the analogous elements of the CKM matrix and its square root.
1102.4011
Benjamin Grinstein
Benjamin Grinstein
What if? On the interplay between Serendipity, Intuition and Conjecture
Talk give at the conference on Flavor Physics and CP Violation - FPCP 2010, May 25-29, 2010, Turin, Italy
PoS FPCP2010:060,2010
null
UCSD/PTH 10-15
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While the Standard Model is in good shape, there are many reasons to believe it is incomplete. There are high expectations that the LHC will shed light on some well studied possibilities, like technicolor and supersymmetry. Emboldened by this optimism, we consider some non-mainstream ideas that if established would change dramatically the way we view the world.
[ { "created": "Sat, 19 Feb 2011 18:23:36 GMT", "version": "v1" } ]
2011-11-10
[ [ "Grinstein", "Benjamin", "" ] ]
While the Standard Model is in good shape, there are many reasons to believe it is incomplete. There are high expectations that the LHC will shed light on some well studied possibilities, like technicolor and supersymmetry. Emboldened by this optimism, we consider some non-mainstream ideas that if established would change dramatically the way we view the world.
hep-ph/0301142
Arnd Brandenburg
A. Brandenburg, M. Maniatis
SUSY QCD corrections to the polarization and spin correlations of top quarks produced in e+e- collisions
15 pages, 10 ps figures
Phys.Lett. B558 (2003) 79-91
10.1016/S0370-2693(03)00210-7
DESY 03-004
hep-ph
null
We compute the supersymmetric QCD corrections to the polarization and the spin correlations of top quarks produced above threshold in e+e- collisions, taking into account arbitrary longitudinal polarization of the initial beams.
[ { "created": "Fri, 17 Jan 2003 18:17:38 GMT", "version": "v1" } ]
2010-04-05
[ [ "Brandenburg", "A.", "" ], [ "Maniatis", "M.", "" ] ]
We compute the supersymmetric QCD corrections to the polarization and the spin correlations of top quarks produced above threshold in e+e- collisions, taking into account arbitrary longitudinal polarization of the initial beams.
1006.1113
Eligio Lisi
G.L. Fogli, E. Lisi, A. Palazzo, A.M. Rotunno
Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior
12 pages, including 6 figures
Phys.Rev.D82:093006,2010
10.1103/PhysRevD.82.093006
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The KamLAND and Borexino experiments have detected electron antineutrinos produced in the decay chains of natural thorium and uranium (Th and U geoneutrinos). We analyze the energy spectra of current geoneutrino data in combination with solar and long-baseline reactor neutrino data, with marginalized three-neutrino oscillation parameters. We consider the case with unconstrained Th and U event rates in KamLAND and Borexino, as well as cases with fewer degrees of freedom, as obtained by successively assuming for both experiments a common Th/U ratio, a common scaling of Th+U event rates, and a chondritic Th/U value. In combination, KamLAND and Borexino can reject the null hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in broad agreement with typical Earth model expectations. Conversely, the results disfavor the hypothesis of a georeactor in the Earth's core, if its power exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is highlighted.
[ { "created": "Sun, 6 Jun 2010 16:30:58 GMT", "version": "v1" } ]
2010-12-13
[ [ "Fogli", "G. L.", "" ], [ "Lisi", "E.", "" ], [ "Palazzo", "A.", "" ], [ "Rotunno", "A. M.", "" ] ]
The KamLAND and Borexino experiments have detected electron antineutrinos produced in the decay chains of natural thorium and uranium (Th and U geoneutrinos). We analyze the energy spectra of current geoneutrino data in combination with solar and long-baseline reactor neutrino data, with marginalized three-neutrino oscillation parameters. We consider the case with unconstrained Th and U event rates in KamLAND and Borexino, as well as cases with fewer degrees of freedom, as obtained by successively assuming for both experiments a common Th/U ratio, a common scaling of Th+U event rates, and a chondritic Th/U value. In combination, KamLAND and Borexino can reject the null hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in broad agreement with typical Earth model expectations. Conversely, the results disfavor the hypothesis of a georeactor in the Earth's core, if its power exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is highlighted.
hep-ph/0402208
Stefano Profumo
S. Profumo, C. E. Yaguna
Gluino Annihilations and Neutralino Dark Matter
13 pages, 6 figures; v4: one figure added, discussion enlarged; final version to appear in Phys. Rev. D
Phys.Rev. D69 (2004) 115009
10.1103/PhysRevD.69.115009
SISSA 15/2004/EP
hep-ph
null
We consider supersymmetric scenarios, compatible with all cosmological and phenomenological requirements, where the lightest SUSY particles (LSPs) are the neutralino and a quasi degenerate gluino. We study the neutralino relic abundance, focusing on gluino (co-)annihilation effects. In case the neutralino is bino-like, in a wide mass window the relic abundance is naturally driven in the correct range for the LSP to be the main cold dark matter constituent. We show that the gluino is the strongest possible coannihilating partner of a bino-like neutralino in the general MSSM. Moreover, contrary to other coannihilation scenarios, gluino pair annihilations always dominate over coannihilation processes, even at relatively large gluino-neutralino mass splittings. Finally, we present prospects for neutralino dark matter detection in the outlined framework.
[ { "created": "Thu, 19 Feb 2004 11:50:45 GMT", "version": "v1" }, { "created": "Mon, 23 Feb 2004 15:26:16 GMT", "version": "v2" }, { "created": "Wed, 3 Mar 2004 14:11:58 GMT", "version": "v3" }, { "created": "Thu, 15 Apr 2004 14:57:26 GMT", "version": "v4" } ]
2007-05-23
[ [ "Profumo", "S.", "" ], [ "Yaguna", "C. E.", "" ] ]
We consider supersymmetric scenarios, compatible with all cosmological and phenomenological requirements, where the lightest SUSY particles (LSPs) are the neutralino and a quasi degenerate gluino. We study the neutralino relic abundance, focusing on gluino (co-)annihilation effects. In case the neutralino is bino-like, in a wide mass window the relic abundance is naturally driven in the correct range for the LSP to be the main cold dark matter constituent. We show that the gluino is the strongest possible coannihilating partner of a bino-like neutralino in the general MSSM. Moreover, contrary to other coannihilation scenarios, gluino pair annihilations always dominate over coannihilation processes, even at relatively large gluino-neutralino mass splittings. Finally, we present prospects for neutralino dark matter detection in the outlined framework.
hep-ph/0205035
John F. Beacom
Matthew K. Sharp, John F. Beacom, Joseph A. Formaggio
Potential for Supernova Neutrino Detection in MiniBooNE
Added references, version to appear in PRD
Phys.Rev. D66 (2002) 013012
10.1103/PhysRevD.66.013012
FERMILAB-Pub-02/073-A
hep-ph astro-ph hep-ex nucl-ex
null
The MiniBooNE detector at Fermilab is designed to search for $\nu_\mu \to \nu_e$ oscillation appearance at $E_\nu \sim 1 {\rm GeV}$ and to make a decisive test of the LSND signal. The main detector (inside a veto shield) is a spherical volume containing 0.680 ktons of mineral oil. This inner volume, viewed by 1280 phototubes, is primarily a \v{C}erenkov medium, as the scintillation yield is low. The entire detector is under a 3 m earth overburden. Though the detector is not optimized for low-energy (tens of MeV) events, and the cosmic-ray muon rate is high (10 kHz), we show that MiniBooNE can function as a useful supernova neutrino detector. Simple trigger-level cuts can greatly reduce the backgrounds due to cosmic-ray muons. For a canonical Galactic supernova at 10 kpc, about 190 supernova $\bar{\nu}_e + p \to e^+ + n$ events would be detected. By adding MiniBooNE to the international network of supernova detectors, the possibility of a supernova being missed would be reduced. Additionally, the paths of the supernova neutrinos through Earth will be different for MiniBooNE and other detectors, thus allowing tests of matter-affected mixing effects on the neutrino signal.
[ { "created": "Fri, 3 May 2002 19:44:18 GMT", "version": "v1" }, { "created": "Fri, 12 Jul 2002 17:11:21 GMT", "version": "v2" } ]
2009-11-07
[ [ "Sharp", "Matthew K.", "" ], [ "Beacom", "John F.", "" ], [ "Formaggio", "Joseph A.", "" ] ]
The MiniBooNE detector at Fermilab is designed to search for $\nu_\mu \to \nu_e$ oscillation appearance at $E_\nu \sim 1 {\rm GeV}$ and to make a decisive test of the LSND signal. The main detector (inside a veto shield) is a spherical volume containing 0.680 ktons of mineral oil. This inner volume, viewed by 1280 phototubes, is primarily a \v{C}erenkov medium, as the scintillation yield is low. The entire detector is under a 3 m earth overburden. Though the detector is not optimized for low-energy (tens of MeV) events, and the cosmic-ray muon rate is high (10 kHz), we show that MiniBooNE can function as a useful supernova neutrino detector. Simple trigger-level cuts can greatly reduce the backgrounds due to cosmic-ray muons. For a canonical Galactic supernova at 10 kpc, about 190 supernova $\bar{\nu}_e + p \to e^+ + n$ events would be detected. By adding MiniBooNE to the international network of supernova detectors, the possibility of a supernova being missed would be reduced. Additionally, the paths of the supernova neutrinos through Earth will be different for MiniBooNE and other detectors, thus allowing tests of matter-affected mixing effects on the neutrino signal.
2002.03981
H\'ector Novales-S\'anchez
E. Mart\'inez-Pascual, G. N\'apoles-Ca\~nedo, H. Novales-S\'anchez, A. Sierra-Mart\'inez, J. J. Toscano
Implications of extra dimensions on the effective charge and the beta function in quantum electrodynamics
Accepted for publication in Physical Review D, 24 pages, 6 figures
Phys.Rev. D101 (2020) no.3, 035034
10.1103/PhysRevD.101.035034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A comprehensive analysis on the photon self-energy, the fermion self-energy, and the fermion vertex function is presented at one loop in the context of quantum electrodynamics (QED) with 1 extra dimension. In 5-dimensional theories, characterized by an infinite number of Kaluza-Klein fields, one-loop amplitudes involve discrete as well as continuous sums, $\sum^\infty_{n=1}\int d^4k$, that could diverge. Using dimensional regularization, we express such sums as products of gamma and Epstein functions, both defined on the complex plane, with divergences arising from poles of these functions in the limit as $ D \to 4$. Using the analytical properties of the Epstein function, we show that the ultraviolet divergences generated by the Kaluza-Klein sums can be consistently renormalized, which means that the corresponding renormalized quantities reduce to the usual ones of QED at the limit of a very large compactification scale $R^{-1}$. The main features of QED at the one-loop level were studied. We use the mass-dependent $\mu$-scheme to calculate, in QED with an arbitrary number $n$ of extra dimensions, a beta function fulfilling all desirable physical requirements. We argue that in this type of theories, with a large mass spectrum covering a wide energy range, beta functions should not be calculated by using mass-independent renormalization schemes. We show that the beta function is finite for any energy $\mu$. In particular, it reduces to the usual QED result $e^3/12\pi^2$ for $m\ll \mu \ll R^{-1}$ and vanishes for $m\gg \mu$, with $m$ the usual fermion mass. Throughout the work, the decoupling nature of all our results obtained from the analytical properties of the Epstein function is stressed.
[ { "created": "Mon, 10 Feb 2020 17:50:01 GMT", "version": "v1" } ]
2020-02-26
[ [ "Martínez-Pascual", "E.", "" ], [ "Nápoles-Cañedo", "G.", "" ], [ "Novales-Sánchez", "H.", "" ], [ "Sierra-Martínez", "A.", "" ], [ "Toscano", "J. J.", "" ] ]
A comprehensive analysis on the photon self-energy, the fermion self-energy, and the fermion vertex function is presented at one loop in the context of quantum electrodynamics (QED) with 1 extra dimension. In 5-dimensional theories, characterized by an infinite number of Kaluza-Klein fields, one-loop amplitudes involve discrete as well as continuous sums, $\sum^\infty_{n=1}\int d^4k$, that could diverge. Using dimensional regularization, we express such sums as products of gamma and Epstein functions, both defined on the complex plane, with divergences arising from poles of these functions in the limit as $ D \to 4$. Using the analytical properties of the Epstein function, we show that the ultraviolet divergences generated by the Kaluza-Klein sums can be consistently renormalized, which means that the corresponding renormalized quantities reduce to the usual ones of QED at the limit of a very large compactification scale $R^{-1}$. The main features of QED at the one-loop level were studied. We use the mass-dependent $\mu$-scheme to calculate, in QED with an arbitrary number $n$ of extra dimensions, a beta function fulfilling all desirable physical requirements. We argue that in this type of theories, with a large mass spectrum covering a wide energy range, beta functions should not be calculated by using mass-independent renormalization schemes. We show that the beta function is finite for any energy $\mu$. In particular, it reduces to the usual QED result $e^3/12\pi^2$ for $m\ll \mu \ll R^{-1}$ and vanishes for $m\gg \mu$, with $m$ the usual fermion mass. Throughout the work, the decoupling nature of all our results obtained from the analytical properties of the Epstein function is stressed.
hep-ph/9708217
Suren Bagdasarov
K. Goulianos
Factorization and Scaling in Hard Diffraction
6pp, LaTex file, uses psfig, 1 PS figure, presented at DIS97
null
10.1063/1.53630
Rockefeller University RU 97/E-29
hep-ph
null
We compare results on diffractive W-boson production at the Tevatron with predictions based on the diffractive structure function measured in deep inelastic scattering at HERA assuming (a) conventional factorization or (b) hard factorization combined with a rapidity gap distribution scaled to the total gap probability. We find that conventional factorization fails, while the scaling prediction agrees with the data.
[ { "created": "Sat, 2 Aug 1997 00:01:56 GMT", "version": "v1" } ]
2009-10-30
[ [ "Goulianos", "K.", "" ] ]
We compare results on diffractive W-boson production at the Tevatron with predictions based on the diffractive structure function measured in deep inelastic scattering at HERA assuming (a) conventional factorization or (b) hard factorization combined with a rapidity gap distribution scaled to the total gap probability. We find that conventional factorization fails, while the scaling prediction agrees with the data.
hep-ph/0211027
Oleg Teryaev
O.V. Teryaev
Spin-dependent, interference and $T-$odd fragmentation and fracture functions
6 Pages, Presented at DIS2002, Krak\'ow, 30.4.--4.5.2002
Acta Phys.Polon. B33 (2002) 3749
null
null
hep-ph
null
Fracture functions, originally suggested to describe the production of diffractive and leading hadrons in semi-inclusive DIS, may be also applied at fixed target energies. They may also include interference and final state interaction, providing a source for azimuthal asymmetries at HERMES and (especially) $\Lambda$ polarization at NOMAD. The recent papers by Brodsky, Hwang and Schmidt, and by Gluck and Reya, may be understood in terms of fracture functions.
[ { "created": "Sun, 3 Nov 2002 16:02:37 GMT", "version": "v1" }, { "created": "Mon, 11 Nov 2002 17:11:47 GMT", "version": "v2" } ]
2007-05-23
[ [ "Teryaev", "O. V.", "" ] ]
Fracture functions, originally suggested to describe the production of diffractive and leading hadrons in semi-inclusive DIS, may be also applied at fixed target energies. They may also include interference and final state interaction, providing a source for azimuthal asymmetries at HERMES and (especially) $\Lambda$ polarization at NOMAD. The recent papers by Brodsky, Hwang and Schmidt, and by Gluck and Reya, may be understood in terms of fracture functions.
0908.1149
Vadim Guzey
V. Guzey (Jefferson Lab), M. Strikman (Penn State U.)
Color fluctuation approximation for multiple interactions in leading twist theory of nuclear shadowing
16 pages, 4 figures. Revised to address the Referee's comments. Matches the published version, PLB 687 (2010) 167.
Phys.Lett.B687:167-173,2010
10.1016/j.physletb.2010.03.008
JLAB-THY-09-1048
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The leading twist theory of nuclear shadowing predicts the shadowing correction to nuclear parton distributions at small $x$ by connecting it to the leading twist hard diffraction in electron-nucleon scattering. The uncertainties of the predictions are related to the shadowing effects resulting from the interaction of the hard probe with $N \ge 3$ nucleons. We argue that the pattern of hard diffraction observed at HERA allows one to reduce these uncertainties. We develop a new approach to the treatment of these multiple interactions, which is based on the concept of the color fluctuations and accounts for the presence of both point-like and hadron-like configurations in the virtual photon wave function. Using the developed framework, we update our predictions for the leading twist nuclear shadowing in nuclear parton distributions of heavy nuclei at small $x$.
[ { "created": "Sat, 8 Aug 2009 05:18:17 GMT", "version": "v1" }, { "created": "Wed, 31 Mar 2010 18:23:45 GMT", "version": "v2" } ]
2015-03-13
[ [ "Guzey", "V.", "", "Jefferson Lab" ], [ "Strikman", "M.", "", "Penn State U." ] ]
The leading twist theory of nuclear shadowing predicts the shadowing correction to nuclear parton distributions at small $x$ by connecting it to the leading twist hard diffraction in electron-nucleon scattering. The uncertainties of the predictions are related to the shadowing effects resulting from the interaction of the hard probe with $N \ge 3$ nucleons. We argue that the pattern of hard diffraction observed at HERA allows one to reduce these uncertainties. We develop a new approach to the treatment of these multiple interactions, which is based on the concept of the color fluctuations and accounts for the presence of both point-like and hadron-like configurations in the virtual photon wave function. Using the developed framework, we update our predictions for the leading twist nuclear shadowing in nuclear parton distributions of heavy nuclei at small $x$.
1006.5356
Tillmann Heidsieck
Andrzej J. Buras, Bj\"orn Duling, Thorsten Feldmann, Tillmann Heidsieck, Christoph Promberger
Lepton Flavour Violation in the Presence of a Fourth Generation of Quarks and Leptons
28 pages, 9 figures, v3: References added, Version to be published in JHEP
JHEP 1009:104,2010
10.1007/JHEP09(2010)104
TUM-HEP-764/10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the rates for the charged lepton flavour violating (LFV) decays l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, the six three-body leptonic decays tau^- -> l_i^- l_j^+ l_k^- and the rate for mu-e conversion in nuclei in the Standard Model (SM3) extended by a fourth generation of quarks and leptons (SM4), assuming that neutrinos are Dirac particles. We also calculate branching ratios for K_L -> mu e, K_L -> pi^0 mu e, B_{d,s} -> mu e, B_{d,s} -> tau e and B_{d,s} -> tau mu. We find that the pattern of the LFV branching ratios in the SM4 differs significantly from the one encountered in the MSSM, allowing to distinguish these two models with the help of LFV processes in a transparent manner. Also differences with respect to the Littlest Higgs model with T-parity are found. Most importantly the branching ratios for l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, tau^- -> e^-e^+e^-, tau^- -> mu^- mu^+ mu^-, tau^- -> e^- mu^+ mu^- and tau^- -> mu^- e^+ e^- can all still be as large as the present experimental upper bounds but not necessarily simultaneously. Also the rate for mu-e conversion in nuclei can reach the corresponding upper bound.
[ { "created": "Mon, 28 Jun 2010 14:07:05 GMT", "version": "v1" }, { "created": "Mon, 26 Jul 2010 11:39:20 GMT", "version": "v2" }, { "created": "Mon, 16 Aug 2010 07:15:45 GMT", "version": "v3" } ]
2014-11-21
[ [ "Buras", "Andrzej J.", "" ], [ "Duling", "Björn", "" ], [ "Feldmann", "Thorsten", "" ], [ "Heidsieck", "Tillmann", "" ], [ "Promberger", "Christoph", "" ] ]
We calculate the rates for the charged lepton flavour violating (LFV) decays l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, the six three-body leptonic decays tau^- -> l_i^- l_j^+ l_k^- and the rate for mu-e conversion in nuclei in the Standard Model (SM3) extended by a fourth generation of quarks and leptons (SM4), assuming that neutrinos are Dirac particles. We also calculate branching ratios for K_L -> mu e, K_L -> pi^0 mu e, B_{d,s} -> mu e, B_{d,s} -> tau e and B_{d,s} -> tau mu. We find that the pattern of the LFV branching ratios in the SM4 differs significantly from the one encountered in the MSSM, allowing to distinguish these two models with the help of LFV processes in a transparent manner. Also differences with respect to the Littlest Higgs model with T-parity are found. Most importantly the branching ratios for l_i -> l_j gamma, tau -> l pi, tau -> l eta('), mu^- -> e^-e^+e^-, tau^- -> e^-e^+e^-, tau^- -> mu^- mu^+ mu^-, tau^- -> e^- mu^+ mu^- and tau^- -> mu^- e^+ e^- can all still be as large as the present experimental upper bounds but not necessarily simultaneously. Also the rate for mu-e conversion in nuclei can reach the corresponding upper bound.
hep-ph/9802356
Andrija Rasin
Andrija Rasin
Hierarchical Quark Mass Matrices
LaTeX, 19 pages. References added, minor changes in text. Version published in Phys. Rev. D
Phys.Rev.D58:096012,1998
10.1103/PhysRevD.58.096012
null
hep-ph
null
I define a set of conditions that the most general hierarchical Yukawa mass matrices have to satisfy so that the leading rotations in the diagonalization matrix are a pair of (2,3) and (1,2) rotations. In addition to Fritzsch structures, examples of such hierarchical structures include also matrices with (1,3) elements of the same order or even much larger than the (1,2) elements. Such matrices can be obtained in the framework of a flavor theory. To leading order, the values of the angle in the (2,3) plane (s_{23}) and the angle in the (1,2) plane (s_{12}) do not depend on the order in which they are taken when diagonalizing. We find that any of the Cabbibo-Kobayashi-Maskawa matrix parametrizations that consists of at least one (1,2) and one (2,3) rotation may be suitable. In the particular case when the s_{13} diagonalization angles are sufficiently small compared to the product s_{12}s_{23}, two special CKM parametrizations emerge: the R_{12}R_{23}R_{12} parametrization follows with s_{23} taken before the s_{12} rotation, and vice versa for the R_{23}R_{12}R_{23} parametrization.
[ { "created": "Wed, 18 Feb 1998 23:00:15 GMT", "version": "v1" }, { "created": "Fri, 9 Oct 1998 14:53:28 GMT", "version": "v2" } ]
2010-11-23
[ [ "Rasin", "Andrija", "" ] ]
I define a set of conditions that the most general hierarchical Yukawa mass matrices have to satisfy so that the leading rotations in the diagonalization matrix are a pair of (2,3) and (1,2) rotations. In addition to Fritzsch structures, examples of such hierarchical structures include also matrices with (1,3) elements of the same order or even much larger than the (1,2) elements. Such matrices can be obtained in the framework of a flavor theory. To leading order, the values of the angle in the (2,3) plane (s_{23}) and the angle in the (1,2) plane (s_{12}) do not depend on the order in which they are taken when diagonalizing. We find that any of the Cabbibo-Kobayashi-Maskawa matrix parametrizations that consists of at least one (1,2) and one (2,3) rotation may be suitable. In the particular case when the s_{13} diagonalization angles are sufficiently small compared to the product s_{12}s_{23}, two special CKM parametrizations emerge: the R_{12}R_{23}R_{12} parametrization follows with s_{23} taken before the s_{12} rotation, and vice versa for the R_{23}R_{12}R_{23} parametrization.
hep-ph/9611215
Agaev Shahin Sabir
Shahin S. Agaev
Resummation of infrared renormalons in the pion electromagnetic form factor calculations
9 pp., 2 fig
null
null
ICTP preprint IC/95/291
hep-ph
null
The pion electromagnetic form factor F_{\pi}(Q^{2}) is calculated at the leading order of pQCD using the running coupling constant (\alpha_{S}(Q^{2}(1-x)(1-y))) approach. The resummed expression for F_{\pi}(Q^{2}) is found. It is shown that the effect of the infrared renormalons can be taken into account by scale-setting procedure $\alpha_{S}(Q^{2}) \rightarrow \alpha_{S}(e^{f(Q^{2})}Q^{2})$ in the leading order expression
[ { "created": "Sat, 2 Nov 1996 16:20:52 GMT", "version": "v1" }, { "created": "Mon, 4 Nov 1996 14:59:44 GMT", "version": "v2" } ]
2008-02-03
[ [ "Agaev", "Shahin S.", "" ] ]
The pion electromagnetic form factor F_{\pi}(Q^{2}) is calculated at the leading order of pQCD using the running coupling constant (\alpha_{S}(Q^{2}(1-x)(1-y))) approach. The resummed expression for F_{\pi}(Q^{2}) is found. It is shown that the effect of the infrared renormalons can be taken into account by scale-setting procedure $\alpha_{S}(Q^{2}) \rightarrow \alpha_{S}(e^{f(Q^{2})}Q^{2})$ in the leading order expression
1901.02295
Jihn E. Kim
Junu Jeong, Jihn E. Kim, Soonkeon Nam
Leptonic CP violation in flipped SU(5) GUT from $Z_{12-I}$ Orbifold Compactification
12 pages, 5 figures
Physics Letters B791 (2019) 215
10.1016/j.physletb.2019.02.035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a phenomenologically acceptable PMNS matrix in a flipped SU(5) model inspired by the compactification of heterotic string $E_8\times E_8'$. To analyze the Jarlskog determinant efficiently, we include the simple Kim-Seo form for the Pontecorbo-Maki-Nakagawa-Sakata matrix. We also noted that $|\delta_{\rm PMNS}|\lesssim 64^{\rm o}$ for the normal hierarchy of neutrino masses with the PDG book parametrization.
[ { "created": "Tue, 8 Jan 2019 13:25:39 GMT", "version": "v1" }, { "created": "Thu, 10 Jan 2019 22:55:38 GMT", "version": "v2" } ]
2019-03-06
[ [ "Jeong", "Junu", "" ], [ "Kim", "Jihn E.", "" ], [ "Nam", "Soonkeon", "" ] ]
We obtain a phenomenologically acceptable PMNS matrix in a flipped SU(5) model inspired by the compactification of heterotic string $E_8\times E_8'$. To analyze the Jarlskog determinant efficiently, we include the simple Kim-Seo form for the Pontecorbo-Maki-Nakagawa-Sakata matrix. We also noted that $|\delta_{\rm PMNS}|\lesssim 64^{\rm o}$ for the normal hierarchy of neutrino masses with the PDG book parametrization.
hep-ph/9307351
Jean Cleymans
N. Bilic, J.Cleymans, K. Redlich and E. Suhonen
Transition from a quark-gluon plasma in the presence of a sharp front
10 pages, manuscript in TeX, 9 figures available as Postscript files, CERN-TH 6923/93
Z.Phys.C63:525-530,1994
10.1007/BF01580333
null
hep-ph
null
The effect of a sharp front separating the quark-gluon plasma phase from the hadronic phase is investigated. Energy-momentum conservation and baryon number conservation constrain the possible temperature jump across the front. If one assumes that the temperature in the hadronic phase is $T\simeq$ 200 MeV , as has been suggested by numerous results from relativistic ion collisions, one can determine the corresponding temperature in the quark phase with the help of continuity equations across the front. The calculations reveal that the quark phase must be in a strongly supercooled state. The stability of this solution with respect to minor modifications is investigated. In particular the effect of an admixture of hadronic matter in the quark phase (e.g. in the form of bubbles) is considered in detail. In the absence of admixture the transition proceeds via a detonation transition and is accompanied by a substantial super-cooling of the quark-gluon plasma phase. The detonation is accompanied by less supercooling if a small fraction of bubbles is allowed. By increasing the fraction of bubbles the supercooling becomes weaker and eventually the transition proceeds via a smoother deflagration wave.
[ { "created": "Wed, 28 Jul 1993 12:40:51 GMT", "version": "v1" } ]
2010-11-01
[ [ "Bilic", "N.", "" ], [ "Cleymans", "J.", "" ], [ "Redlich", "K.", "" ], [ "Suhonen", "E.", "" ] ]
The effect of a sharp front separating the quark-gluon plasma phase from the hadronic phase is investigated. Energy-momentum conservation and baryon number conservation constrain the possible temperature jump across the front. If one assumes that the temperature in the hadronic phase is $T\simeq$ 200 MeV , as has been suggested by numerous results from relativistic ion collisions, one can determine the corresponding temperature in the quark phase with the help of continuity equations across the front. The calculations reveal that the quark phase must be in a strongly supercooled state. The stability of this solution with respect to minor modifications is investigated. In particular the effect of an admixture of hadronic matter in the quark phase (e.g. in the form of bubbles) is considered in detail. In the absence of admixture the transition proceeds via a detonation transition and is accompanied by a substantial super-cooling of the quark-gluon plasma phase. The detonation is accompanied by less supercooling if a small fraction of bubbles is allowed. By increasing the fraction of bubbles the supercooling becomes weaker and eventually the transition proceeds via a smoother deflagration wave.
hep-ph/9508286
null
R. Ragazzon and D. Treleani
Multiparton interactions and production of minijets in high energy hadronic collisions
TeX file, 20 pages, 4 figures available on request
Phys.Rev. D53 (1996) 55-62
10.1103/PhysRevD.53.55
UTS-DFT-95-06
hep-ph
null
We discuss the inclusive cross section to produce two minijets with a large separation in rapidity in high energy hadronic collisions. The contribution to the inclusive cross section from the exchange of a BFKL Pomeron is compared with the contribution from the exchange of two BFKL Pomerons, which is induced by the unitarization of the semi-hard interaction. The effect of the multiple exchange is studied both as a function of the azimuthal correlation and as a function of the transverse momentum of the observed minijets.
[ { "created": "Fri, 11 Aug 1995 12:41:44 GMT", "version": "v1" } ]
2009-10-28
[ [ "Ragazzon", "R.", "" ], [ "Treleani", "D.", "" ] ]
We discuss the inclusive cross section to produce two minijets with a large separation in rapidity in high energy hadronic collisions. The contribution to the inclusive cross section from the exchange of a BFKL Pomeron is compared with the contribution from the exchange of two BFKL Pomerons, which is induced by the unitarization of the semi-hard interaction. The effect of the multiple exchange is studied both as a function of the azimuthal correlation and as a function of the transverse momentum of the observed minijets.
1504.00517
Ashutosh Alok
Ashutosh Kumar Alok, Subhashish Banerjee, Dinesh Kumar, S. Uma Sankar, David London
New-physics signals of a model with a vector-singlet up-type quark
30 pages, no figures. arXiv admin note: text overlap with arXiv:1402.1023
Phys. Rev. D 92, 013002 (2015)
10.1103/PhysRevD.92.013002
UdeM-GPP-TH-15-241
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The VuQ model involves the addition of a vector isosinglet up-type quark to the standard model. In this model the full CKM quark mixing matrix is 4 X 3. Using present flavor-physics data, we perform a fit to this full CKM matrix, looking for signals of new physics (NP). We find that the VuQ model is very strongly constrained. There are no hints of NP in the CKM matrix, and any VuQ contributions to loop-level flavor-changing b -> s, b -> d and s -> d transitions are very small. There can be significant enhancements of the branching ratios of the flavor-changing decays t -> u Z and t -> c Z, but these are still below present detection levels.
[ { "created": "Thu, 2 Apr 2015 11:49:19 GMT", "version": "v1" } ]
2016-03-10
[ [ "Alok", "Ashutosh Kumar", "" ], [ "Banerjee", "Subhashish", "" ], [ "Kumar", "Dinesh", "" ], [ "Sankar", "S. Uma", "" ], [ "London", "David", "" ] ]
The VuQ model involves the addition of a vector isosinglet up-type quark to the standard model. In this model the full CKM quark mixing matrix is 4 X 3. Using present flavor-physics data, we perform a fit to this full CKM matrix, looking for signals of new physics (NP). We find that the VuQ model is very strongly constrained. There are no hints of NP in the CKM matrix, and any VuQ contributions to loop-level flavor-changing b -> s, b -> d and s -> d transitions are very small. There can be significant enhancements of the branching ratios of the flavor-changing decays t -> u Z and t -> c Z, but these are still below present detection levels.
hep-ph/0012319
Gennaro Corcella
Gennaro Corcella (Rochester U.), Elinor K. Irish (Rochester U.), Michael H. Seymour (RAL)
HERWIG for Top Physics at the Linear Collider
5 pages, 3 figures. Talk given at Linear Collider Workshop 2000, Fermi National Accelerator Laboratory, Batavia, IL, U.S.A., 24-28 October 2000
null
10.1063/1.1394341
UR-1626 ER/40685/963
hep-ph
null
We discuss recent improvement in the treatment of gluon radiation in top production and decay in e+e- processes according to the HERWIG event generator and show studies on the top mass reconstruction at the future Linear Collider.
[ { "created": "Fri, 22 Dec 2000 23:06:08 GMT", "version": "v1" } ]
2009-10-31
[ [ "Corcella", "Gennaro", "", "Rochester U." ], [ "Irish", "Elinor K.", "", "Rochester U." ], [ "Seymour", "Michael H.", "", "RAL" ] ]
We discuss recent improvement in the treatment of gluon radiation in top production and decay in e+e- processes according to the HERWIG event generator and show studies on the top mass reconstruction at the future Linear Collider.
1710.11010
William Javier Torres Bobadilla Dr.
Jose Llanes Jurado, German Rodrigo and William J. Torres Bobadilla
From Jacobi off-shell currents to integral relations
22 pages, 3 figures
null
null
IFIC/17-17
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study off-shell currents built from the Jacobi identity of the kinematic numerators of $gg\to X$ with $X=ss,q\bar{q},gg$. We find that these currents can be schematically written in terms of three-point interaction Feynman rules. This representation allows for a straightforward understanding of the Colour-Kinematics duality as well as for the construction of the building blocks for the generation of higher-multiplicity tree-level and multi-loop numerators. We also provide one-loop integral relations through the Loop-Tree duality formalism with potential applications and advantages for the computation of relevant physical processes at the Large Hadron Collider. We illustrate these integral relations with the explicit examples of QCD one-loop numerators of $gg\to ss$.
[ { "created": "Mon, 30 Oct 2017 15:27:39 GMT", "version": "v1" } ]
2017-10-31
[ [ "Jurado", "Jose Llanes", "" ], [ "Rodrigo", "German", "" ], [ "Bobadilla", "William J. Torres", "" ] ]
In this paper, we study off-shell currents built from the Jacobi identity of the kinematic numerators of $gg\to X$ with $X=ss,q\bar{q},gg$. We find that these currents can be schematically written in terms of three-point interaction Feynman rules. This representation allows for a straightforward understanding of the Colour-Kinematics duality as well as for the construction of the building blocks for the generation of higher-multiplicity tree-level and multi-loop numerators. We also provide one-loop integral relations through the Loop-Tree duality formalism with potential applications and advantages for the computation of relevant physical processes at the Large Hadron Collider. We illustrate these integral relations with the explicit examples of QCD one-loop numerators of $gg\to ss$.
1305.0021
Lian-Tao Wang
Jing-Yuan Chen, Edward W. Kolb, Lian-Tao Wang
Dark matter coupling to electroweak gauge and Higgs bosons: an effective field theory approach
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If dark matter is a new species of particle produced in the early universe as a cold thermal relic (a weakly-interacting massive particle-WIMP), its present abundance, its scattering with matter in direct-detection experiments, its present-day annihilation signature in indirect-detection experiments, and its production and detection at colliders, depend crucially on the WIMP coupling to standard-model (SM) particles. It is usually assumed that the WIMP couples to the SM sector through its interactions with quarks and leptons. In this paper we explore the possibility that the WIMP coupling to the SM sector is via electroweak gauge and Higgs bosons. In the absence of an ultraviolet-complete particle-physics model, we employ effective field theory to describe the WIMP--SM coupling. We consider both scalars and Dirac fermions as possible dark-matter candidates. Starting with an exhaustive list of operators up to dimension 8, we present detailed calculation of dark-matter annihilations to all possible final states, including gamma gamma, gamma Z, gamma h, ZZ, Zh, W+ W-, hh, and f fbar, and demonstrate the correlations among them. We compute the mass scale of the effective field theory necessary to obtain the correct dark-matter mass density, and well as the resulting photon line signals.
[ { "created": "Tue, 30 Apr 2013 20:31:11 GMT", "version": "v1" } ]
2013-05-02
[ [ "Chen", "Jing-Yuan", "" ], [ "Kolb", "Edward W.", "" ], [ "Wang", "Lian-Tao", "" ] ]
If dark matter is a new species of particle produced in the early universe as a cold thermal relic (a weakly-interacting massive particle-WIMP), its present abundance, its scattering with matter in direct-detection experiments, its present-day annihilation signature in indirect-detection experiments, and its production and detection at colliders, depend crucially on the WIMP coupling to standard-model (SM) particles. It is usually assumed that the WIMP couples to the SM sector through its interactions with quarks and leptons. In this paper we explore the possibility that the WIMP coupling to the SM sector is via electroweak gauge and Higgs bosons. In the absence of an ultraviolet-complete particle-physics model, we employ effective field theory to describe the WIMP--SM coupling. We consider both scalars and Dirac fermions as possible dark-matter candidates. Starting with an exhaustive list of operators up to dimension 8, we present detailed calculation of dark-matter annihilations to all possible final states, including gamma gamma, gamma Z, gamma h, ZZ, Zh, W+ W-, hh, and f fbar, and demonstrate the correlations among them. We compute the mass scale of the effective field theory necessary to obtain the correct dark-matter mass density, and well as the resulting photon line signals.
2102.11145
Tuomas Tenkanen
Philipp M. Schicho, Tuomas V. I. Tenkanen and Juuso \"Osterman
Robust approach to thermal resummation: Standard Model meets a singlet
86 pages, 2 figures and 141 Feynman diagrams
null
10.1007/JHEP06(2021)130
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Perturbation theory alone fails to describe thermodynamics of the electroweak phase transition. We review a technique combining perturbative and non-perturbative methods to overcome this challenge. Accordingly, the principal theme is a tutorial of high-temperature dimensional reduction. We present an explicit derivation with a real singlet scalar and compute the thermal effective potential at two-loop order. In particular, we detail the dimensional reduction for a real-singlet extended Standard Model. The resulting effective theory will impact future non-perturbative studies based on lattice simulations as well as purely perturbative investigations.
[ { "created": "Mon, 22 Feb 2021 16:15:59 GMT", "version": "v1" } ]
2021-07-07
[ [ "Schicho", "Philipp M.", "" ], [ "Tenkanen", "Tuomas V. I.", "" ], [ "Österman", "Juuso", "" ] ]
Perturbation theory alone fails to describe thermodynamics of the electroweak phase transition. We review a technique combining perturbative and non-perturbative methods to overcome this challenge. Accordingly, the principal theme is a tutorial of high-temperature dimensional reduction. We present an explicit derivation with a real singlet scalar and compute the thermal effective potential at two-loop order. In particular, we detail the dimensional reduction for a real-singlet extended Standard Model. The resulting effective theory will impact future non-perturbative studies based on lattice simulations as well as purely perturbative investigations.
2010.14581
Maxim Khlopov
Maxim Yu. Khlopov
Multi-messenger cosmology of new physics
Plenary talk at ICPPA2020 conference
null
10.1088/1742-6596/1690/1/012182
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observational evidence for the inflationary cosmology with baryosynthesis and dark matter/energy can be viewed as the messenger for new physics, which governed the Universe origin, evolution and structure. To specify the physics beyond the Standard model (BSM), underlying the modern cosmological paradigm additional model dependent messengers are proposed, involving multi-component and composite dark matter, meta-stable particles, primordial black holes and antimatter domains in baryon asymmetrical Universe.
[ { "created": "Tue, 27 Oct 2020 19:44:34 GMT", "version": "v1" } ]
2021-02-03
[ [ "Khlopov", "Maxim Yu.", "" ] ]
The observational evidence for the inflationary cosmology with baryosynthesis and dark matter/energy can be viewed as the messenger for new physics, which governed the Universe origin, evolution and structure. To specify the physics beyond the Standard model (BSM), underlying the modern cosmological paradigm additional model dependent messengers are proposed, involving multi-component and composite dark matter, meta-stable particles, primordial black holes and antimatter domains in baryon asymmetrical Universe.
1012.4750
Pratishruti Saha
Debajyoti Choudhury, Rohini M. Godbole, Saurabh D. Rindani, Pratishruti Saha
Top polarization, forward-backward asymmetry and new physics
Version published in Physical Review D
Phys.Rev.D84:014023,2011
10.1103/PhysRevD.84.014023
CERN-PH-TH/2010-314
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider how the measurement of top polarization at the Tevatron can be used to characterise and discriminate among different new physics models that have been suggested to explain the anomalous top forward-backward asymmetry reported at the Tevatron. This has the advantage of catching the essence of the parity violating effect characteristic to the different suggested new physics models. Other observables constructed from these asymmetries are shown to be useful in discriminating between the models, even after taking into account the statistical errors. Finally, we discuss some signals at the 7 TeV LHC.
[ { "created": "Tue, 21 Dec 2010 18:05:25 GMT", "version": "v1" }, { "created": "Wed, 19 Jan 2011 16:14:47 GMT", "version": "v2" }, { "created": "Wed, 20 Jul 2011 04:34:56 GMT", "version": "v3" } ]
2015-03-17
[ [ "Choudhury", "Debajyoti", "" ], [ "Godbole", "Rohini M.", "" ], [ "Rindani", "Saurabh D.", "" ], [ "Saha", "Pratishruti", "" ] ]
We consider how the measurement of top polarization at the Tevatron can be used to characterise and discriminate among different new physics models that have been suggested to explain the anomalous top forward-backward asymmetry reported at the Tevatron. This has the advantage of catching the essence of the parity violating effect characteristic to the different suggested new physics models. Other observables constructed from these asymmetries are shown to be useful in discriminating between the models, even after taking into account the statistical errors. Finally, we discuss some signals at the 7 TeV LHC.
hep-ph/9405284
Felix Schlumpf
Felix Schlumpf
The Form Factors of the Nucleons
10 pages ReVTeX, 5 figures included, SLAC-PUB-6502
AIPConf.Proc.334:583-586,1995
null
null
hep-ph
null
We demonstrate that a relativistic constituent quark model can give nucleon form factors that agree well with recent, accurate measurements. The relativistic features of the model and the specific form of the wave function are essential for the result. (Talk given at 14th International Conference on Few-Body Problems in Physics, Williamsburg, Virginia, USA, May 26-31, 1994)
[ { "created": "Fri, 13 May 1994 17:11:56 GMT", "version": "v1" } ]
2009-09-25
[ [ "Schlumpf", "Felix", "" ] ]
We demonstrate that a relativistic constituent quark model can give nucleon form factors that agree well with recent, accurate measurements. The relativistic features of the model and the specific form of the wave function are essential for the result. (Talk given at 14th International Conference on Few-Body Problems in Physics, Williamsburg, Virginia, USA, May 26-31, 1994)
1611.01859
Chris Korthals Altes
Chris P. Korthals Altes
Raymond and instantons: some recollections and the use of ADHM
20 pages, two figures
null
10.1016/j.nuclphysb.2016.07.021
null
hep-ph physics.hist-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After the discovery of the BRST identities in 1974 Raymond spent some two years mostly on instantons. In those years we had a small group at the Centre Physique Th\'eorique in Marseille discussing the physics and mathematics of instantons. The upshot of our discussions can be found in a set of lectures given by Raymond in Erice in 1977 and a year later in a Physics Reports volume. I present some recollections of that period; mostly how we were influenced by the twistor approach. I discuss the Atiyah-Drinfeld-Hitchin-Manin (ADHM) method to obtain instantons ("calorons") in thermal QCD following earlier work. The building blocks are a prepotential and a gauge invariant propagator. Then I will give surprisingly simple results in terms of these building blocks for the one loop vacuum response to a change in caloron parameters and some physical consequences for the effective action, in particular screening properties.
[ { "created": "Sun, 6 Nov 2016 23:05:21 GMT", "version": "v1" } ]
2016-12-21
[ [ "Altes", "Chris P. Korthals", "" ] ]
After the discovery of the BRST identities in 1974 Raymond spent some two years mostly on instantons. In those years we had a small group at the Centre Physique Th\'eorique in Marseille discussing the physics and mathematics of instantons. The upshot of our discussions can be found in a set of lectures given by Raymond in Erice in 1977 and a year later in a Physics Reports volume. I present some recollections of that period; mostly how we were influenced by the twistor approach. I discuss the Atiyah-Drinfeld-Hitchin-Manin (ADHM) method to obtain instantons ("calorons") in thermal QCD following earlier work. The building blocks are a prepotential and a gauge invariant propagator. Then I will give surprisingly simple results in terms of these building blocks for the one loop vacuum response to a change in caloron parameters and some physical consequences for the effective action, in particular screening properties.
1712.07611
C\'edric Weiland
K. Moffat, S. Pascoli and C. Weiland
Equivalence between massless neutrinos and lepton number conservation in fermionic singlet extensions of the Standard Model
22+1 pages, 2 plots in 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the most general necessary and sufficient condition for three massless light neutrinos in variants of the type I seesaw mechanism in which we introduce an arbitrary number of fermionic gauge singlets. We find that having massless light neutrinos is equivalent to enforcing the conservation of lepton number. As a consequence, any symmetry that leads to massless light neutrinos will contain as an unbroken subgroup a conserved lepton number. This will be important for searches for heavy sterile neutrinos since in general the light neutrino masses will be proportional to small lepton number violating parameters that will also suppress lepton number violating signatures.
[ { "created": "Wed, 20 Dec 2017 17:57:32 GMT", "version": "v1" } ]
2017-12-21
[ [ "Moffat", "K.", "" ], [ "Pascoli", "S.", "" ], [ "Weiland", "C.", "" ] ]
We discuss the most general necessary and sufficient condition for three massless light neutrinos in variants of the type I seesaw mechanism in which we introduce an arbitrary number of fermionic gauge singlets. We find that having massless light neutrinos is equivalent to enforcing the conservation of lepton number. As a consequence, any symmetry that leads to massless light neutrinos will contain as an unbroken subgroup a conserved lepton number. This will be important for searches for heavy sterile neutrinos since in general the light neutrino masses will be proportional to small lepton number violating parameters that will also suppress lepton number violating signatures.