id
stringlengths
9
14
submitter
stringlengths
1
56
authors
stringlengths
5
7.68k
title
stringlengths
3
299
comments
stringlengths
1
1.15k
journal-ref
stringlengths
9
298
doi
stringlengths
12
97
report-no
stringlengths
3
341
categories
stringclasses
869 values
license
stringclasses
9 values
orig_abstract
stringlengths
16
2.44k
versions
listlengths
1
39
update_date
stringlengths
10
10
authors_parsed
listlengths
1
565
abstract
stringlengths
13
2.44k
hep-ph/0312291
Hiroyuki Abe
Hiroyuki Abe
Dynamical symmetry breaking on a brane with bulk gauge theory
3 pages, 6 figures, Talk given at Summer Institute '03, Yamanashi, Japan (12-19 August, 2003); typos corrected, references added
null
null
KAIST-TH 2003/16
hep-ph hep-th
null
We analyze a structure of dynamical chiral symmetry breaking in orbifold gauge theories with matter fields (fermions) on the fixed point. We find that the boundary chiral phase structure of QED and QCD on the orbifold is quite nontrivial depending on the bulk constitution, and we claim that particular attention should be given to the dynamically generated masses in various kinds of phenomenological orbifold models.
[ { "created": "Sat, 20 Dec 2003 06:45:38 GMT", "version": "v1" }, { "created": "Tue, 3 Aug 2004 10:19:09 GMT", "version": "v2" } ]
2007-05-23
[ [ "Abe", "Hiroyuki", "" ] ]
We analyze a structure of dynamical chiral symmetry breaking in orbifold gauge theories with matter fields (fermions) on the fixed point. We find that the boundary chiral phase structure of QED and QCD on the orbifold is quite nontrivial depending on the bulk constitution, and we claim that particular attention should be given to the dynamically generated masses in various kinds of phenomenological orbifold models.
hep-ph/0511258
Abdessamad Abada
A. Abada, N. Daira-Aifa and K. Bouakaz
Ultrasoft Quark Damping in Hot QCD
16 pages
Int.J.Mod.Phys.A21:5317-5332,2006
10.1142/S0217751X06033052
null
hep-ph
null
We determine the quark damping rates in the context of next-to-leading order hard-thermal-loop summed perturbation of high-temperature QCD where weak coupling is assumed. The quarks are ultrasoft. Three types of divergent behavior are encountered: infrared, light-cone and at specific points determined by the gluon energies. The infrared divergence persists and is logarithmic whereas the two others are circumvented.
[ { "created": "Tue, 22 Nov 2005 17:18:27 GMT", "version": "v1" } ]
2009-11-11
[ [ "Abada", "A.", "" ], [ "Daira-Aifa", "N.", "" ], [ "Bouakaz", "K.", "" ] ]
We determine the quark damping rates in the context of next-to-leading order hard-thermal-loop summed perturbation of high-temperature QCD where weak coupling is assumed. The quarks are ultrasoft. Three types of divergent behavior are encountered: infrared, light-cone and at specific points determined by the gluon energies. The infrared divergence persists and is logarithmic whereas the two others are circumvented.
1912.09369
Ruud Peeters
Dani\"el Boer and Ruud Peeters
Fine-tuning and the doublet-triplet splitting problem in the minimal $SU(5)$ GUT
14 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we analyse the doublet-triplet splitting problem in the minimal non-super-symmetric $SU(5)$ GUT. We take into account the full symmetry breaking pattern with both high scale $SU(5)$ breaking and electroweak symmetry breaking. Our analysis shows that the only phenomenologically acceptable model has three vevs, with a strong hierarchy determined by the minimization conditions. The amount of fine-tuning in the model is then numerically evaluated by looking at the effect of variation of input parameters on both the minimization conditions and the bosonic masses. Regarding the vevs as output parameters, a large amount of fine-tuning is required in this scenario, which is an expression of the doublet-triplet splitting problem. We show that this problem is more general, since a model with coupled scalar sectors will in general never realise a hierarchy in vevs. To avoid these problems we advocate imposing the desired hierarchy in vevs as part of the theory. We argue for this viewpoint because the $SU(5)$ breaking and electroweak symmetry breaking need to be adjusted to each other anyway and cannot be regarded as independent mechanisms. We suggest that not only the symmetry breaking pattern needs to be imposed, but also the scales at which the breakings happen. We show quantitatively that the generic theory with hierarchy imposed does not require any fine-tuning of the free parameters which can all be natural and perturbative as desired.
[ { "created": "Thu, 19 Dec 2019 16:53:02 GMT", "version": "v1" }, { "created": "Wed, 29 Apr 2020 12:53:26 GMT", "version": "v2" } ]
2020-04-30
[ [ "Boer", "Daniël", "" ], [ "Peeters", "Ruud", "" ] ]
In this paper we analyse the doublet-triplet splitting problem in the minimal non-super-symmetric $SU(5)$ GUT. We take into account the full symmetry breaking pattern with both high scale $SU(5)$ breaking and electroweak symmetry breaking. Our analysis shows that the only phenomenologically acceptable model has three vevs, with a strong hierarchy determined by the minimization conditions. The amount of fine-tuning in the model is then numerically evaluated by looking at the effect of variation of input parameters on both the minimization conditions and the bosonic masses. Regarding the vevs as output parameters, a large amount of fine-tuning is required in this scenario, which is an expression of the doublet-triplet splitting problem. We show that this problem is more general, since a model with coupled scalar sectors will in general never realise a hierarchy in vevs. To avoid these problems we advocate imposing the desired hierarchy in vevs as part of the theory. We argue for this viewpoint because the $SU(5)$ breaking and electroweak symmetry breaking need to be adjusted to each other anyway and cannot be regarded as independent mechanisms. We suggest that not only the symmetry breaking pattern needs to be imposed, but also the scales at which the breakings happen. We show quantitatively that the generic theory with hierarchy imposed does not require any fine-tuning of the free parameters which can all be natural and perturbative as desired.
2211.10512
Pedro Bicudo
Pedro Bicudo and Jos\'e Em\'ilio Ribeiro
QCD vacuum replicas are metastable
8 pages, 8 figures, contribution to the XVth Quark Confinement and the Hadron Spectrum Conference, Aug 2022 University of Stavanger
null
10.1051/epjconf/202227403009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the meson spectra in the excited QCD vacua, denominated replicas. We find all mesons have real masses, with no tachyons, thus showing the QCD replicas are indeed metastable.
[ { "created": "Fri, 18 Nov 2022 21:31:43 GMT", "version": "v1" } ]
2023-01-11
[ [ "Bicudo", "Pedro", "" ], [ "Ribeiro", "José Emílio", "" ] ]
We study the meson spectra in the excited QCD vacua, denominated replicas. We find all mesons have real masses, with no tachyons, thus showing the QCD replicas are indeed metastable.
hep-ph/9701321
Rod Crewther
R. J. Crewther (Universities of Berne and Adelaide)
Relating inclusive e+e- annihilation to electroproduction sum rules in Quantum Chromodynamics
10 pages, LaTeX 2e with packages cite, multicol, and curves, 2 figures in LaTeX
Phys.Lett. B397 (1997) 137-142
10.1016/S0370-2693(97)00157-3
BUTP-97/01, ADP-97-1/T242
hep-ph hep-th
null
The Broadhurst-Kataev conjecture, that the ``discrepancy'' in the connection with the $\pi^0 \to \gamma\gamma$ anomaly equals the beta function $\beta(\bar{\alpha})$ times a power series in the effective coupling $\bar{\alpha}$, is proven to all orders of perturbative quantum chromodynamics. The use of nested short-distance expansions is justified via Weinberg's power-counting theorem.
[ { "created": "Fri, 17 Jan 1997 14:58:58 GMT", "version": "v1" } ]
2009-10-30
[ [ "Crewther", "R. J.", "", "Universities of Berne and Adelaide" ] ]
The Broadhurst-Kataev conjecture, that the ``discrepancy'' in the connection with the $\pi^0 \to \gamma\gamma$ anomaly equals the beta function $\beta(\bar{\alpha})$ times a power series in the effective coupling $\bar{\alpha}$, is proven to all orders of perturbative quantum chromodynamics. The use of nested short-distance expansions is justified via Weinberg's power-counting theorem.
hep-ph/0109070
George Grispos
A.P. Contogouris (Athens U. & McGill U.), G. Grispos (Athens U.)
Approximate calculation of corrections at NLO and NNLO
4 pages, 3 figures, presented at "QCD 2000", Montpellier, France, 5-12 July 2000
Nucl.Phys.Proc.Suppl.96:94-97,2001
10.1016/S0920-5632(01)01115-X
null
hep-ph
null
For processes involving structure functions and/or fragmentation functions, arguments that there is a part that dominates the NLO corrections are briefly reviewed. The arguments are tested against more recent NLO and in particular NNLO calculations.
[ { "created": "Sun, 9 Sep 2001 15:40:24 GMT", "version": "v1" } ]
2010-01-18
[ [ "Contogouris", "A. P.", "", "Athens U. & McGill U." ], [ "Grispos", "G.", "", "Athens U." ] ]
For processes involving structure functions and/or fragmentation functions, arguments that there is a part that dominates the NLO corrections are briefly reviewed. The arguments are tested against more recent NLO and in particular NNLO calculations.
2405.08880
Manuel Szewc
David Marzocca, Manuel Szewc, Michele Tammaro
Direct CKM determination from W decays at future lepton colliders
15 figures, 3 figures
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We project the reach of future lepton colliders for measuring CKM elements from direct observations of $W$ decays. We focus our attention to $|V_{cs}|$ and $|V_{cb}|$ determinations, using FCC-ee as case study. We employ state-of-the-art jet flavor taggers to obtain the projected sensitivity, and scan over tagger performances to show their effect. We conclude that future lepton collider can sizeably improve the sensitivity on $|V_{cs}|$ and $|V_{cb}|$, albeit the achievable reach will strongly depend on the level of systematic uncertainties on tagger parameters.
[ { "created": "Tue, 14 May 2024 18:00:55 GMT", "version": "v1" } ]
2024-05-16
[ [ "Marzocca", "David", "" ], [ "Szewc", "Manuel", "" ], [ "Tammaro", "Michele", "" ] ]
We project the reach of future lepton colliders for measuring CKM elements from direct observations of $W$ decays. We focus our attention to $|V_{cs}|$ and $|V_{cb}|$ determinations, using FCC-ee as case study. We employ state-of-the-art jet flavor taggers to obtain the projected sensitivity, and scan over tagger performances to show their effect. We conclude that future lepton collider can sizeably improve the sensitivity on $|V_{cs}|$ and $|V_{cb}|$, albeit the achievable reach will strongly depend on the level of systematic uncertainties on tagger parameters.
2112.03944
Zhongbo Kang
Alexander M. Czajka, Zhong-Bo Kang, Henry Ma, Fanyi Zhao
Quantum Simulation of Chiral Phase Transitions
25 pages, 6 figures, published version
JHEP 08, 209 (2022)
10.1007/JHEP08(2022)209
null
hep-ph hep-ex hep-lat nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Nambu-Jona-Lasinio (NJL) model has been widely studied for investigating the chiral phase structure of strongly interacting matter. The study of the thermodynamics of field theories within the framework of Lattice Field Theory is limited by the sign problem, which prevents Monte Carlo evaluation of the functional integral at a finite chemical potential. Using the quantum imaginary time evolution (QITE) algorithm, we construct a quantum simulation for the $(1+1)$ dimensional NJL model at finite temperature and finite chemical potential. We observe consistency among digital quantum simulation, exact diagonalization, and analytical solution, indicating further applications of quantum computing in simulating QCD thermodynamics.
[ { "created": "Tue, 7 Dec 2021 19:04:20 GMT", "version": "v1" }, { "created": "Mon, 5 Dec 2022 17:40:59 GMT", "version": "v2" } ]
2022-12-06
[ [ "Czajka", "Alexander M.", "" ], [ "Kang", "Zhong-Bo", "" ], [ "Ma", "Henry", "" ], [ "Zhao", "Fanyi", "" ] ]
The Nambu-Jona-Lasinio (NJL) model has been widely studied for investigating the chiral phase structure of strongly interacting matter. The study of the thermodynamics of field theories within the framework of Lattice Field Theory is limited by the sign problem, which prevents Monte Carlo evaluation of the functional integral at a finite chemical potential. Using the quantum imaginary time evolution (QITE) algorithm, we construct a quantum simulation for the $(1+1)$ dimensional NJL model at finite temperature and finite chemical potential. We observe consistency among digital quantum simulation, exact diagonalization, and analytical solution, indicating further applications of quantum computing in simulating QCD thermodynamics.
hep-ph/0612229
Christopher McMullen
C.D. McMullen and S. Nandi
Collider Implications of a Non-Universal Higgs
16 pages, 5 figures, submitted as a PDF file (thus PostScript may be unavailable), updated references
Phys.Rev.D75:095001,2007
10.1103/PhysRevD.75.095001
OSU-HEP-06-12
hep-ph
null
We consider in detail the possibility that the Higgs is wholly or partially excluded from propagating into one otherwise universal extra dimension. This exclusion of the Higgs from propagating into an otherwise universal extra dimension violates tree-level Kaluza-Klein number conservation in the Yukawa interactions. As a consequence, there is inter-mode mixing between fermions. For example, zero-mode fermions mix with their associated Kaluza-Klein excitations. This is in contrast to the original universal extra dimensions scenario, in which conservation of Kaluza-Klein number prohibits such inter-mode mixing. Inter-mode mixing is especially significant for the top quark, since its mass (171.4 +/- 2.1 GeV) is approximately one-half the current Tevatron mass bound (~350-400 GeV) for Kaluza-Klein excitations of quarks propagating into universal extra dimensions. We compute the effects that mixing among the zero-modes and lowest-lying Kaluza-Klein excitations has on the lightest third-generation charge 2/3 quark mass eigenvalue in the non-universal Higgs model with one otherwise universal extra dimension. Another consequence of the inter-mode mixing is that the Kaluza-Klein excitations of the fermions can decay to a zero-mode Higgs and a corresponding zero-mode fermion. As a result, the pair production of Kaluza-Klein excitations of the top quark would lead to two zero-mode Higgs bosons plus a zero-mode top quark/anti-quark pair. We compute the cross section that the non-universal Higgs model contributes to Higgs production at the Large Hadron Collider. The effect is quite large: For example, the Kaluza-Klein contribution to Higgs production is comparable to or larger than the Standard Model contribution, depending on the Higgs mass, for compactification scales up to about 600 GeV.
[ { "created": "Tue, 19 Dec 2006 17:56:51 GMT", "version": "v1" }, { "created": "Tue, 20 Feb 2007 18:50:15 GMT", "version": "v2" } ]
2008-11-26
[ [ "McMullen", "C. D.", "" ], [ "Nandi", "S.", "" ] ]
We consider in detail the possibility that the Higgs is wholly or partially excluded from propagating into one otherwise universal extra dimension. This exclusion of the Higgs from propagating into an otherwise universal extra dimension violates tree-level Kaluza-Klein number conservation in the Yukawa interactions. As a consequence, there is inter-mode mixing between fermions. For example, zero-mode fermions mix with their associated Kaluza-Klein excitations. This is in contrast to the original universal extra dimensions scenario, in which conservation of Kaluza-Klein number prohibits such inter-mode mixing. Inter-mode mixing is especially significant for the top quark, since its mass (171.4 +/- 2.1 GeV) is approximately one-half the current Tevatron mass bound (~350-400 GeV) for Kaluza-Klein excitations of quarks propagating into universal extra dimensions. We compute the effects that mixing among the zero-modes and lowest-lying Kaluza-Klein excitations has on the lightest third-generation charge 2/3 quark mass eigenvalue in the non-universal Higgs model with one otherwise universal extra dimension. Another consequence of the inter-mode mixing is that the Kaluza-Klein excitations of the fermions can decay to a zero-mode Higgs and a corresponding zero-mode fermion. As a result, the pair production of Kaluza-Klein excitations of the top quark would lead to two zero-mode Higgs bosons plus a zero-mode top quark/anti-quark pair. We compute the cross section that the non-universal Higgs model contributes to Higgs production at the Large Hadron Collider. The effect is quite large: For example, the Kaluza-Klein contribution to Higgs production is comparable to or larger than the Standard Model contribution, depending on the Higgs mass, for compactification scales up to about 600 GeV.
1001.5401
Thomas Teubner
T. Teubner, K. Hagiwara, R. Liao, A. D. Martin, Daisuke Nomura
Update of g-2 of the muon and Delta alpha
6 pages, 10 figures, proceedings of the PhiPsi09 conference, 13-16 Oct. 2009, Beijing, China
null
10.1088/1674-1137/34/6/019
LTH 864
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update our Standard Model predictions for g-2 of the muon and for the hadronic contributions to the running of the QED coupling, Delta alpha^5_had(M_Z^2). Particular emphasis is put on recent changes in the hadronic contributions from new data in the 2pi channel and from the energy region just below 2 GeV.
[ { "created": "Fri, 29 Jan 2010 13:22:34 GMT", "version": "v1" } ]
2015-05-18
[ [ "Teubner", "T.", "" ], [ "Hagiwara", "K.", "" ], [ "Liao", "R.", "" ], [ "Martin", "A. D.", "" ], [ "Nomura", "Daisuke", "" ] ]
We update our Standard Model predictions for g-2 of the muon and for the hadronic contributions to the running of the QED coupling, Delta alpha^5_had(M_Z^2). Particular emphasis is put on recent changes in the hadronic contributions from new data in the 2pi channel and from the energy region just below 2 GeV.
hep-ph/0701261
Jens Erler
Jens Erler
SM Precision Constraints at the LHC/ILC
9 pages, 2 figures, talk presented at the VI Latin American Symposium on High Energy Physics (SILAFAE 2006), Hotel Krystal, Puerto Vallarta, Mexico, Nov. 1-8, 2006
AIPConf.Proc.917:244-251,2007
10.1063/1.2751963
null
hep-ph hep-ex
null
The prospects for electroweak precision physics at the LHC and the ILC are reviewed. This includes projections for measurements of the effective Z pole weak mixing angle, sin^2 theta_W (eff.), as well as top quark, W boson, and Higgs scalar properties. The upcoming years may also see very precise determinations of sin^2 theta_W (eff.) from lower energies.
[ { "created": "Tue, 30 Jan 2007 21:24:48 GMT", "version": "v1" } ]
2008-11-26
[ [ "Erler", "Jens", "" ] ]
The prospects for electroweak precision physics at the LHC and the ILC are reviewed. This includes projections for measurements of the effective Z pole weak mixing angle, sin^2 theta_W (eff.), as well as top quark, W boson, and Higgs scalar properties. The upcoming years may also see very precise determinations of sin^2 theta_W (eff.) from lower energies.
1702.08853
Fernand Renard M
Fernand M. Renard
CSM constraints on the $gg\to ZH$ process
22 pages, 13 figures; references added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study more deeply the sensitivity of the $ZH$ production process in gluon-gluon collisions to the details of a possible Higgs and top quark compositeness. We establish a relation between Higgs and top quark form factors which would keep the basic cancellation appearing in SM and satisfy the concept of CSM. We give illustrations showing the spectacular consequences of various choices preserving or violating this CSM constraint.
[ { "created": "Tue, 28 Feb 2017 16:36:47 GMT", "version": "v1" }, { "created": "Tue, 7 Mar 2017 15:35:00 GMT", "version": "v2" }, { "created": "Mon, 13 Mar 2017 12:19:20 GMT", "version": "v3" } ]
2017-03-14
[ [ "Renard", "Fernand M.", "" ] ]
We study more deeply the sensitivity of the $ZH$ production process in gluon-gluon collisions to the details of a possible Higgs and top quark compositeness. We establish a relation between Higgs and top quark form factors which would keep the basic cancellation appearing in SM and satisfy the concept of CSM. We give illustrations showing the spectacular consequences of various choices preserving or violating this CSM constraint.
hep-ph/0110233
Svjetlana Fajfer
S. Fajfer, P. Singer
Constraints on heavy Z' couplings from \Delta S = 2 B^- -> K^- K^- \pi^+ decay
6 pages
Phys.Rev. D65 (2002) 017301
10.1103/PhysRevD.65.017301
null
hep-ph
null
The heavy Z' boson with family nonuniversal couplings can introduce flavour changing effects. Constraints on nondiagonal Z' couplings coming from the \mu-e conversion in a muonic atom, K^0 - \bar{K^0} and B - \bar{B} mixing, epsilon and epsilon'/ \epsilon CP- violating coefficients have been already established. By using the OPAL upper bound of the branching ratio for the B^- -> K^- K^- \pi^+ decay, we indicate additional constraints on the Z' couplings. We comment also on the constraints of Z' couplings coming from the b->d d \bar{s} transition. The constraint obtained here from the upper bound of the B^- -> K^- K^- \pi^+ decay involves a different combination of couplings than those previously presented, but is much weaker.
[ { "created": "Wed, 17 Oct 2001 14:41:10 GMT", "version": "v1" } ]
2009-11-07
[ [ "Fajfer", "S.", "" ], [ "Singer", "P.", "" ] ]
The heavy Z' boson with family nonuniversal couplings can introduce flavour changing effects. Constraints on nondiagonal Z' couplings coming from the \mu-e conversion in a muonic atom, K^0 - \bar{K^0} and B - \bar{B} mixing, epsilon and epsilon'/ \epsilon CP- violating coefficients have been already established. By using the OPAL upper bound of the branching ratio for the B^- -> K^- K^- \pi^+ decay, we indicate additional constraints on the Z' couplings. We comment also on the constraints of Z' couplings coming from the b->d d \bar{s} transition. The constraint obtained here from the upper bound of the B^- -> K^- K^- \pi^+ decay involves a different combination of couplings than those previously presented, but is much weaker.
2301.07914
Bin Yan
Hai Tao Li, Bin Yan and C. -P. Yuan
Discriminating between Higgs Production Mechanisms via Jet Charge at the LHC
6 pages, 5 figures, version accepted by PRL
null
10.1103/PhysRevLett.131.041802
MSUHEP-23-001
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Discriminating the Higgs production mechanisms plays a crucial role in directly measuring the couplings of Higgs to gauge bosons for probing the nature of the electroweak symmetry breaking. We propose a novel method to distinguish the Higgs production mechanisms at the LHC by utilizing the jet charge asymmetry of the two leading forward jets in Higgs plus two jets production. This novel observable provides a way to disentangle the $W$-fusion from the $Z$-fusion and gluon fusion processes for the first time, due to the electric charge correlation of the two leading jets in the events. We show that the Higgs couplings to gauge bosons can be well constrained and its conclusion does not depend on the other possible new physics effects which modify the Higgs total or partial width. We also discuss the complementary roles between the proposed jet charge asymmetry measurement and the Higgs signal strength measurements at the HL-LHC in determining the Higgs couplings.
[ { "created": "Thu, 19 Jan 2023 06:52:37 GMT", "version": "v1" }, { "created": "Sat, 22 Jul 2023 01:03:58 GMT", "version": "v2" } ]
2023-08-02
[ [ "Li", "Hai Tao", "" ], [ "Yan", "Bin", "" ], [ "Yuan", "C. -P.", "" ] ]
Discriminating the Higgs production mechanisms plays a crucial role in directly measuring the couplings of Higgs to gauge bosons for probing the nature of the electroweak symmetry breaking. We propose a novel method to distinguish the Higgs production mechanisms at the LHC by utilizing the jet charge asymmetry of the two leading forward jets in Higgs plus two jets production. This novel observable provides a way to disentangle the $W$-fusion from the $Z$-fusion and gluon fusion processes for the first time, due to the electric charge correlation of the two leading jets in the events. We show that the Higgs couplings to gauge bosons can be well constrained and its conclusion does not depend on the other possible new physics effects which modify the Higgs total or partial width. We also discuss the complementary roles between the proposed jet charge asymmetry measurement and the Higgs signal strength measurements at the HL-LHC in determining the Higgs couplings.
hep-ph/9712524
Vladimir N. Baier
V. N. Baier and V. M. Katkov
The Landau-Pomeranchuk-Migdal effect in a thin target
LaTeX2.09, 20 pages, 4 eps figures included
null
null
BudkerINP 97-105
hep-ph
null
The Landau, Pomeranchuk, Migdal (LPM) effect (suppression of the bremsstrahlung from high energy electron due to a multiple scattering of an emitting electron in dense media) is considered for the case when thickness of a target is of the order or less than the formation length of radiation. The effects of the polarization of a medium and transition radiation are taken into account as well. Qualitative picture of the phenomenon is discussed in detail. Comparison with recent experimental data is carried out.
[ { "created": "Fri, 26 Dec 1997 08:55:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baier", "V. N.", "" ], [ "Katkov", "V. M.", "" ] ]
The Landau, Pomeranchuk, Migdal (LPM) effect (suppression of the bremsstrahlung from high energy electron due to a multiple scattering of an emitting electron in dense media) is considered for the case when thickness of a target is of the order or less than the formation length of radiation. The effects of the polarization of a medium and transition radiation are taken into account as well. Qualitative picture of the phenomenon is discussed in detail. Comparison with recent experimental data is carried out.
hep-ph/9505392
Sheldon Stone
Stephen Playfer and Sheldon Stone (Syracuse University)
Rare b Decays
To be published in International Journal of Modern Physics Letters A This is a 34 page review article, the file is uuencoded postscript
Int.J.Mod.Phys. A10 (1995) 4107-4138
10.1142/S0217751X9500190X
HEPSY 95-01
hep-ph
null
Rare b decays provide a unique opportunity to measure Standard Model parameters and probe beyond the Standard Model. We review here the experimentalprogress made in measuring these decays, and the importance of future measurements, including the possible observation of CP violation.
[ { "created": "Fri, 26 May 1995 20:20:33 GMT", "version": "v1" }, { "created": "Sat, 27 May 1995 14:08:14 GMT", "version": "v2" }, { "created": "Mon, 29 May 1995 00:13:32 GMT", "version": "v3" }, { "created": "Mon, 29 May 1995 17:53:03 GMT", "version": "v4" } ]
2009-10-28
[ [ "Playfer", "Stephen", "", "Syracuse University" ], [ "Stone", "Sheldon", "", "Syracuse University" ] ]
Rare b decays provide a unique opportunity to measure Standard Model parameters and probe beyond the Standard Model. We review here the experimentalprogress made in measuring these decays, and the importance of future measurements, including the possible observation of CP violation.
hep-ph/0310059
George Rupp
Michael D. Scadron, George Rupp, and Eef van Beveren
CP Violation and $\Delta I=1/2$ Enhancement for $K \to \pi\pi$, $K \to \pi\pi\gamma$ Weak Decays
Plain LaTeX, 12 pages, 4 EPS figures. PACS numbers: 11.30.Er, 12.15.Lk, 13.20.Eb, 13.40.Ks. Version 2: 14 pages, improved presentation, introductory and concluding remarks as well as references added; accepted for publication in Mod. Phys. Lett. A (2004)
Mod.Phys.Lett.A19:2267-2278,2004
10.1142/S0217732304015567
null
hep-ph
null
Data indicate that $\Delta I=1/2$ transitions account for 4.5-4.7% of both CP conserving and CP violating $K \to 2\pi$ decays, as well as CP conserving radiative $K \to \pi\pi\gamma$ processes. Observed $K \to \pi\pi\gamma/\pi\pi$ branching ratios are shown to scale near $\alpha/\pi$ or $\alpha/2\pi$. The $K_L$-$K_S$ mixing angle $\phi$ and the semileptonic weak-rate asymmetry $\delta$ are reviewed, and theory is shown to be consistent with data. Also, $K \to 2\pi$ $\Delta I=1/2$ dominance is studied in the context of the chiral constituent quark model, displaying again excellent agreement with data. Finally, indirect and direct kaon CP violation are successfully described in the framework of photon-mediated loop graphs. This suggests that kaon CPV can be understood via second-order weak transitions, radiatively corrected.
[ { "created": "Sat, 4 Oct 2003 13:44:34 GMT", "version": "v1" }, { "created": "Sat, 14 Aug 2004 16:47:10 GMT", "version": "v2" } ]
2008-11-26
[ [ "Scadron", "Michael D.", "" ], [ "Rupp", "George", "" ], [ "van Beveren", "Eef", "" ] ]
Data indicate that $\Delta I=1/2$ transitions account for 4.5-4.7% of both CP conserving and CP violating $K \to 2\pi$ decays, as well as CP conserving radiative $K \to \pi\pi\gamma$ processes. Observed $K \to \pi\pi\gamma/\pi\pi$ branching ratios are shown to scale near $\alpha/\pi$ or $\alpha/2\pi$. The $K_L$-$K_S$ mixing angle $\phi$ and the semileptonic weak-rate asymmetry $\delta$ are reviewed, and theory is shown to be consistent with data. Also, $K \to 2\pi$ $\Delta I=1/2$ dominance is studied in the context of the chiral constituent quark model, displaying again excellent agreement with data. Finally, indirect and direct kaon CP violation are successfully described in the framework of photon-mediated loop graphs. This suggests that kaon CPV can be understood via second-order weak transitions, radiatively corrected.
1104.2043
Matthew Baumgart
Matthew Baumgart and Brock Tweedie
Discriminating Top-Antitop Resonances using Azimuthal Decay Correlations
24 pages plus appendices, 6 figures. v2: added references, updated AFB model, expanded discussion of SM interference for spin-0 particle
JHEP 1109:049,2011
10.1007/JHEP09(2011)049
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top-antitop pairs produced in the decay of a new heavy resonance will exhibit spin correlations that contain valuable coupling information. When the tops decay, these correlations imprint themselves on the angular patterns of the final quarks and leptons. While many approaches to the measurement of top spin correlations are known, the most common ones require detailed kinematic reconstructions and are insensitive to some important spin interference effects. In particular, spin-1 resonances with mostly-vector or mostly-axial couplings to top cannot be easily discriminated from one another without appealing to mass-suppressed effects or to more model-dependent interference with continuum Standard Model production. Here, we propose to probe the structure of a resonance's couplings to tops by measuring the azimuthal angles of the tops' decay products about the production axis. These angles exhibit modulations which are typically O(0.1-1), and which by themselves allow for discrimination of spin-0 from higher spins, measurement of the CP-phase for spin-0, and measurement of the vector/axial composition for spins 1 and 2. For relativistic tops, the azimuthal decay angles can be well-approximated without detailed knowledge of the tops' velocities, and appear to be robust against imperfect energy measurements and neutrino reconstructions. We illustrate this point in the highly challenging dileptonic decay mode, which also exhibits the largest modulations. We comment on the relevance of these observables for testing axigluon-like models that explain the top quark A_FB anomaly at the Tevatron, through direct production at the LHC.
[ { "created": "Mon, 11 Apr 2011 20:00:11 GMT", "version": "v1" }, { "created": "Sat, 27 Aug 2011 01:18:27 GMT", "version": "v2" } ]
2015-03-19
[ [ "Baumgart", "Matthew", "" ], [ "Tweedie", "Brock", "" ] ]
Top-antitop pairs produced in the decay of a new heavy resonance will exhibit spin correlations that contain valuable coupling information. When the tops decay, these correlations imprint themselves on the angular patterns of the final quarks and leptons. While many approaches to the measurement of top spin correlations are known, the most common ones require detailed kinematic reconstructions and are insensitive to some important spin interference effects. In particular, spin-1 resonances with mostly-vector or mostly-axial couplings to top cannot be easily discriminated from one another without appealing to mass-suppressed effects or to more model-dependent interference with continuum Standard Model production. Here, we propose to probe the structure of a resonance's couplings to tops by measuring the azimuthal angles of the tops' decay products about the production axis. These angles exhibit modulations which are typically O(0.1-1), and which by themselves allow for discrimination of spin-0 from higher spins, measurement of the CP-phase for spin-0, and measurement of the vector/axial composition for spins 1 and 2. For relativistic tops, the azimuthal decay angles can be well-approximated without detailed knowledge of the tops' velocities, and appear to be robust against imperfect energy measurements and neutrino reconstructions. We illustrate this point in the highly challenging dileptonic decay mode, which also exhibits the largest modulations. We comment on the relevance of these observables for testing axigluon-like models that explain the top quark A_FB anomaly at the Tevatron, through direct production at the LHC.
1110.3363
Luis A. Sanchez
Alejandro Jaramillo and Luis A. Sanchez
FCNC, CP violation and implications for some rare decays in an SU(4)_L X U(1)_X extension of the standard model
23 pages, 11 figures. Renormalization group QCD effects on flavor changing observables corrected. References added. Version accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.84.115001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extensions of the standard model (SM) with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X (3-4-1 extensions) where anomaly cancellation takes place between the fermion families (three-family models) predict the existence of two new heavy neutral gauge bosons which transmit flavor changing neutral currents (FCNC) at tree-level. In this work, in the context of a three-family 3-4-1 extension which does not contain particles with exotic electric charges, we study the constraints coming from neutral meson mixing on the parameters of the extension associated to tree level FCNC effects. Taking into account experimental measurements of observables related to K and B meson mixing and including new CP-violating phases, we study the resulting bounds for angles and phases in the mixing matrix for the down-quark sector, as well as the implications of these bounds for the modifications in the amplitudes of the clean rare decays K^+ -> \pi^+ \bar\nu \nu, K_{L} -> \pi^0 \nu \bar\nu, K_L -> \pi^0 l^+ l^- (l=e,\mu) and B_{d/s} -> \mu^+ \mu^-.
[ { "created": "Fri, 14 Oct 2011 23:52:34 GMT", "version": "v1" }, { "created": "Fri, 11 Nov 2011 19:30:55 GMT", "version": "v2" } ]
2015-05-30
[ [ "Jaramillo", "Alejandro", "" ], [ "Sanchez", "Luis A.", "" ] ]
Extensions of the standard model (SM) with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X (3-4-1 extensions) where anomaly cancellation takes place between the fermion families (three-family models) predict the existence of two new heavy neutral gauge bosons which transmit flavor changing neutral currents (FCNC) at tree-level. In this work, in the context of a three-family 3-4-1 extension which does not contain particles with exotic electric charges, we study the constraints coming from neutral meson mixing on the parameters of the extension associated to tree level FCNC effects. Taking into account experimental measurements of observables related to K and B meson mixing and including new CP-violating phases, we study the resulting bounds for angles and phases in the mixing matrix for the down-quark sector, as well as the implications of these bounds for the modifications in the amplitudes of the clean rare decays K^+ -> \pi^+ \bar\nu \nu, K_{L} -> \pi^0 \nu \bar\nu, K_L -> \pi^0 l^+ l^- (l=e,\mu) and B_{d/s} -> \mu^+ \mu^-.
0808.1153
Kenji Morita
Young-Ho Song, Su Houng Lee, Kenji Morita
In-medium modification of P-wave charmonia from QCD sum rules
7 pages, 6 figures, to be published in Phys.Rev.C
Phys.Rev.C79:014907,2009
10.1103/PhysRevC.79.014907
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the changes of the masses and widths of $\chi_{c0}$ and $\chi_{c1}$ in hot gluonic matter near $T_c$ and in nuclear medium using QCD sum rules. As in the previous works for the $J/\psi$ and $\eta_c$, in-medium effects are incorporated through the changes of gluon condensates. Twist-2 terms for the $^3 P_0 (\chi_{c0})$ and $^3 P_1 (\chi_{c1})$ are also included for the first time. The results show that larger mass shifts and width broadenings take place as compared to the $S$-wave states. As the critical change take place near $T_c$, related measurements can reveal critical phenomenon in QCD.
[ { "created": "Fri, 8 Aug 2008 05:39:05 GMT", "version": "v1" }, { "created": "Sat, 10 Jan 2009 07:52:42 GMT", "version": "v2" } ]
2009-04-28
[ [ "Song", "Young-Ho", "" ], [ "Lee", "Su Houng", "" ], [ "Morita", "Kenji", "" ] ]
We investigate the changes of the masses and widths of $\chi_{c0}$ and $\chi_{c1}$ in hot gluonic matter near $T_c$ and in nuclear medium using QCD sum rules. As in the previous works for the $J/\psi$ and $\eta_c$, in-medium effects are incorporated through the changes of gluon condensates. Twist-2 terms for the $^3 P_0 (\chi_{c0})$ and $^3 P_1 (\chi_{c1})$ are also included for the first time. The results show that larger mass shifts and width broadenings take place as compared to the $S$-wave states. As the critical change take place near $T_c$, related measurements can reveal critical phenomenon in QCD.
2311.15981
Oleksandr Sobol Dr.
Anastasia V. Lysenko and Oleksandr O. Sobol
Quantum kinetic approach to the Schwinger production of scalar particles in an expanding universe
22 pages
General Relativity and Gravitation (2024) 56:39
10.1007/s10714-024-03226-8
MS-TP-23-50
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Schwinger pair creation of scalar charged particles by a homogeneous electric field in an expanding universe in the quantum kinetic approach. We introduce an adiabatic vacuum for the scalar field based on the Wentzel-Kramers-Brillouin solution to the mode equation in conformal time and apply the formalism of Bogolyubov coefficients to derive a system of quantum Vlasov equations for three real kinetic functions. Compared to the analogous system of equations previously reported in the literature, the new one has two advantages. First, its solutions exhibit a faster decrease at large momenta which makes it more suitable for numerical computations. Second, it predicts no particle creation in the case of conformally coupled massless scalar field in the vanishing electric field, i.e., it respects the conformal symmetry of the system. We identify the ultraviolet divergences in the electric current and energy-momentum tensor of produced particles and introduce the corresponding counterterms in order to cancel them.
[ { "created": "Mon, 27 Nov 2023 16:27:50 GMT", "version": "v1" }, { "created": "Mon, 11 Dec 2023 14:01:28 GMT", "version": "v2" }, { "created": "Tue, 2 Apr 2024 12:34:19 GMT", "version": "v3" } ]
2024-04-03
[ [ "Lysenko", "Anastasia V.", "" ], [ "Sobol", "Oleksandr O.", "" ] ]
We study the Schwinger pair creation of scalar charged particles by a homogeneous electric field in an expanding universe in the quantum kinetic approach. We introduce an adiabatic vacuum for the scalar field based on the Wentzel-Kramers-Brillouin solution to the mode equation in conformal time and apply the formalism of Bogolyubov coefficients to derive a system of quantum Vlasov equations for three real kinetic functions. Compared to the analogous system of equations previously reported in the literature, the new one has two advantages. First, its solutions exhibit a faster decrease at large momenta which makes it more suitable for numerical computations. Second, it predicts no particle creation in the case of conformally coupled massless scalar field in the vanishing electric field, i.e., it respects the conformal symmetry of the system. We identify the ultraviolet divergences in the electric current and energy-momentum tensor of produced particles and introduce the corresponding counterterms in order to cancel them.
hep-ph/9512238
null
X. Artru
Some aspects of transversity
4 pages, latex, no figures
null
null
null
hep-ph
null
The specificities of transverse polarization with respect to helicity of ultrarelativistic fermions are pointed out. For massless fermions, a covariant transversity four-vector is defined, up to a kind of gauge transformation. The tranversity distribution of quarks in a nucleon is defined. Its possible connection to the magnetic or electric dipole moment of the baryon is conjectured. Consequences of the approximate chiral invariance on transverse spin asymmetries in hard processes are enumerated. The "sheared jet effect" introduced by Collins for measuring the transverse polarization of a final quark is presented.
[ { "created": "Tue, 5 Dec 1995 14:29:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Artru", "X.", "" ] ]
The specificities of transverse polarization with respect to helicity of ultrarelativistic fermions are pointed out. For massless fermions, a covariant transversity four-vector is defined, up to a kind of gauge transformation. The tranversity distribution of quarks in a nucleon is defined. Its possible connection to the magnetic or electric dipole moment of the baryon is conjectured. Consequences of the approximate chiral invariance on transverse spin asymmetries in hard processes are enumerated. The "sheared jet effect" introduced by Collins for measuring the transverse polarization of a final quark is presented.
2212.04954
Luca Rottoli
Luca Buonocore, Simone Devoto, Stefan Kallweit, Javier Mazzitelli, Luca Rottoli, Chiara Savoini
Associated production of a $W$ boson and massive bottom quarks at next-to-next-to-leading order in QCD
8 pages, 2 figures, 2 tables. Final version published in PRD
null
10.1103/PhysRevD.107.074032
ZU-TH 60/22, TIF-UNIMI-2022-22, PSI-PR-22-35
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the first calculation for the hadroproduction of a $W$ boson in association with a massive bottom ($b$) quark-antiquark pair at next-to-next-to-leading order (NNLO) in QCD perturbation theory. We exploit the hierarchy between the $b$ quark mass and the characteristic energy scale of the process to obtain a reliable analytic expression for the two-loop virtual amplitude with three massive legs, starting from the corresponding result available for massless bottom quarks. The use of massive $b$ quarks avoids the ambiguities associated with the correct flavour assignment in massless calculations, paving the way to a more realistic comparison with experimental data. We present phenomenological results considering proton-proton collisions at centre-of-mass energy $\sqrt{s}=13.6$ TeV for inclusive $Wb \bar b$ production and within a fiducial region relevant for the associated production of a $W$ boson and a Higgs boson decaying into a $b \bar b$ pair, for which $Wb \bar b$ production represents one of the most relevant backgrounds. We find that the NNLO corrections are substantial and that their inclusion is mandatory to obtain reliable predictions.
[ { "created": "Fri, 9 Dec 2022 16:04:46 GMT", "version": "v1" }, { "created": "Thu, 11 Apr 2024 11:52:36 GMT", "version": "v2" } ]
2024-04-12
[ [ "Buonocore", "Luca", "" ], [ "Devoto", "Simone", "" ], [ "Kallweit", "Stefan", "" ], [ "Mazzitelli", "Javier", "" ], [ "Rottoli", "Luca", "" ], [ "Savoini", "Chiara", "" ] ]
We present the first calculation for the hadroproduction of a $W$ boson in association with a massive bottom ($b$) quark-antiquark pair at next-to-next-to-leading order (NNLO) in QCD perturbation theory. We exploit the hierarchy between the $b$ quark mass and the characteristic energy scale of the process to obtain a reliable analytic expression for the two-loop virtual amplitude with three massive legs, starting from the corresponding result available for massless bottom quarks. The use of massive $b$ quarks avoids the ambiguities associated with the correct flavour assignment in massless calculations, paving the way to a more realistic comparison with experimental data. We present phenomenological results considering proton-proton collisions at centre-of-mass energy $\sqrt{s}=13.6$ TeV for inclusive $Wb \bar b$ production and within a fiducial region relevant for the associated production of a $W$ boson and a Higgs boson decaying into a $b \bar b$ pair, for which $Wb \bar b$ production represents one of the most relevant backgrounds. We find that the NNLO corrections are substantial and that their inclusion is mandatory to obtain reliable predictions.
hep-ph/0007340
Robert S. Plant
Robert S. Plant, Michael C. Birse (University of Manchester)
Mesonic fluctuations in a nonlocal Nambu-Jona-Lasinio model
22 pages (RevTeX), 12 figures (using graphicx.sty), v3 has improved numerics
Nucl.Phys. A703 (2002) 717-744
10.1016/S0375-9474(01)01669-4
TH/00/05
hep-ph nucl-th
null
The effects of meson fluctuations are studied in a nonlocal generalization of the Nambu-Jona-Lasinio model, by including terms of next-to-leading order (NLO) in 1/N_c. In the model with only scalar and pseudoscalar interactions NLO contributions to the quark condensate are found to be very small. This is a result of cancellation between virtual mesons and Fock terms, which occurs for the parameter sets of most interest. In the quark self-energy, similar cancellations arise in the tadpole diagrams, although not in other NLO pieces which contribute at the \sim 25% level. The effects on pion properties are also found to be small. NLO contributions from real $\pi\pi$ intermediate states increase the sigma meson mass by $\sim 30%$. In an extended model with vector and axial interactions, there are indications that NLO effects could be larger.
[ { "created": "Fri, 28 Jul 2000 15:41:19 GMT", "version": "v1" }, { "created": "Tue, 27 Feb 2001 11:05:22 GMT", "version": "v2" }, { "created": "Tue, 13 Nov 2001 12:18:44 GMT", "version": "v3" } ]
2009-10-31
[ [ "Plant", "Robert S.", "", "University of Manchester" ], [ "Birse", "Michael C.", "", "University of Manchester" ] ]
The effects of meson fluctuations are studied in a nonlocal generalization of the Nambu-Jona-Lasinio model, by including terms of next-to-leading order (NLO) in 1/N_c. In the model with only scalar and pseudoscalar interactions NLO contributions to the quark condensate are found to be very small. This is a result of cancellation between virtual mesons and Fock terms, which occurs for the parameter sets of most interest. In the quark self-energy, similar cancellations arise in the tadpole diagrams, although not in other NLO pieces which contribute at the \sim 25% level. The effects on pion properties are also found to be small. NLO contributions from real $\pi\pi$ intermediate states increase the sigma meson mass by $\sim 30%$. In an extended model with vector and axial interactions, there are indications that NLO effects could be larger.
hep-ph/0503145
Carl Shakin
Hu Li, C. M. Shakin, Xiangdong Li
Relativistic Calculation of the Width of the Theta (1540) Pentaquark
11 pages, 5 figures
Phys.Rev.C71:068203,2005
10.1103/PhysRevC.71.068203
BCCNT: 05/314/333
hep-ph hep-lat nucl-th
null
We calculate the width of the Theta(1540) pentaquark in a relativistic model in which the pentaquark is considered to be composed of a scalar diquark and a spin 1/2 triquark. We consider both positive and negative parity for the pentaquark. There is a single parameter in our model which we vary and which describes the size of the pentaquark. If the pentaquark size is somewhat smaller than that of the nucleon, we find quite small widths for the pentaquark of about 1 MeV or less. Our model of confinement plays an important role in our analysis and makes it possible to use Feynman diagrams to describe the decay of the pentaquark.
[ { "created": "Tue, 15 Mar 2005 15:17:12 GMT", "version": "v1" } ]
2011-07-19
[ [ "Li", "Hu", "" ], [ "Shakin", "C. M.", "" ], [ "Li", "Xiangdong", "" ] ]
We calculate the width of the Theta(1540) pentaquark in a relativistic model in which the pentaquark is considered to be composed of a scalar diquark and a spin 1/2 triquark. We consider both positive and negative parity for the pentaquark. There is a single parameter in our model which we vary and which describes the size of the pentaquark. If the pentaquark size is somewhat smaller than that of the nucleon, we find quite small widths for the pentaquark of about 1 MeV or less. Our model of confinement plays an important role in our analysis and makes it possible to use Feynman diagrams to describe the decay of the pentaquark.
2112.08801
Alejandro Segarra
Thomas Schwetz and Alejandro Segarra
On T violation in non-standard neutrino oscillation scenarios
10 pages, 2 figures, 1 table
null
10.1103/PhysRevD.105.055001
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We discuss time reversal (T) violation in neutrino oscillations in generic new physics scenarios. A general parameterization is adopted to describe flavour evolution, which captures a wide range of new physics effects, including non-standard neutrino interactions, non-unitarity, and sterile neutrinos in a model-independent way. In this framework, we discuss general properties of time reversal in the context of long-baseline neutrino experiments. Special attention is given to fundamental versus environmental T violation in the presence of generic new physics. We point out that T violation in the disappearance channel requires new physics which modifies flavour mixing at neutrino production and detection. We use time-dependent perturbation theory to study the effect of non-constant matter density along the neutrino path, and quantify the effects for the well studied baselines of the DUNE, T2HK, and T2HKK projects. The material presented here provides the phenomenological background for the model-independent test of T violation proposed by us in Ref. [1].
[ { "created": "Thu, 16 Dec 2021 11:35:16 GMT", "version": "v1" } ]
2022-03-14
[ [ "Schwetz", "Thomas", "" ], [ "Segarra", "Alejandro", "" ] ]
We discuss time reversal (T) violation in neutrino oscillations in generic new physics scenarios. A general parameterization is adopted to describe flavour evolution, which captures a wide range of new physics effects, including non-standard neutrino interactions, non-unitarity, and sterile neutrinos in a model-independent way. In this framework, we discuss general properties of time reversal in the context of long-baseline neutrino experiments. Special attention is given to fundamental versus environmental T violation in the presence of generic new physics. We point out that T violation in the disappearance channel requires new physics which modifies flavour mixing at neutrino production and detection. We use time-dependent perturbation theory to study the effect of non-constant matter density along the neutrino path, and quantify the effects for the well studied baselines of the DUNE, T2HK, and T2HKK projects. The material presented here provides the phenomenological background for the model-independent test of T violation proposed by us in Ref. [1].
2404.03692
Jo\~ao Paulo Da Silva Melo
Jo\~ao Paulo S. Melo and Jos\'e A. Helay\"el-Neto
Re-assessing special aspects of Dirac fermions in presence of Lorentz-symmetry violation
14 pages, 2 figures
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
This paper focuses on additional inspections concerning the fermionic sector of the Standard Model Extension (SME). In this context, our main effort in this contribution is to investigate effects of Lorentz-symmetry violation (LSV) on the Klein Paradox, the Zitterbewegung and its phenomenology in connection to Condensed Matter Physics, Atomic Physics, and Astrophysics. Finally, we discuss a particular realization of LSV in the Dirac equation, considering an asymmetry between space and time due to a scale factor present in the linear momentum of the fermion, but which does not touch its time derivative. We go further and extend the implications of this asymmetry in the situation the scale factor becomes space-time dependent to compute its influence on the kinematics of the Compton effect with the extended dispersion relation for the fermion that scatters the photon.
[ { "created": "Wed, 3 Apr 2024 02:00:35 GMT", "version": "v1" } ]
2024-04-08
[ [ "Melo", "João Paulo S.", "" ], [ "Helayël-Neto", "José A.", "" ] ]
This paper focuses on additional inspections concerning the fermionic sector of the Standard Model Extension (SME). In this context, our main effort in this contribution is to investigate effects of Lorentz-symmetry violation (LSV) on the Klein Paradox, the Zitterbewegung and its phenomenology in connection to Condensed Matter Physics, Atomic Physics, and Astrophysics. Finally, we discuss a particular realization of LSV in the Dirac equation, considering an asymmetry between space and time due to a scale factor present in the linear momentum of the fermion, but which does not touch its time derivative. We go further and extend the implications of this asymmetry in the situation the scale factor becomes space-time dependent to compute its influence on the kinematics of the Compton effect with the extended dispersion relation for the fermion that scatters the photon.
hep-ph/0207153
Maxim V. Polyakov
M.V. Polyakov, A.G. Shuvaev
On "dual" parametrizations of generalized parton distributions
19 pages
null
null
RUB-TP2-12/02
hep-ph
null
We propose a parametrization for the generalized parton distributions (GPDs) which is based on representation of parton distributions as an infinite series of t-channel exchanges. The entire generalized parton distribution is given as an infinite sum over contributions of generalized light-cone distribution amplitudes in the t-channel. We also discuss the relations of the lowest Mellin moments of GPDs to basic mechanical characteristics of the nucleon as a compound system.
[ { "created": "Fri, 12 Jul 2002 18:16:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Polyakov", "M. V.", "" ], [ "Shuvaev", "A. G.", "" ] ]
We propose a parametrization for the generalized parton distributions (GPDs) which is based on representation of parton distributions as an infinite series of t-channel exchanges. The entire generalized parton distribution is given as an infinite sum over contributions of generalized light-cone distribution amplitudes in the t-channel. We also discuss the relations of the lowest Mellin moments of GPDs to basic mechanical characteristics of the nucleon as a compound system.
0906.2435
Jens Erler
Jens Erler, Paul Langacker, Shoaib Munir and Eduardo Rojas
Improved Constraints on Z' Bosons from Electroweak Precision Data
18 pages, 10 figures, final version as it will appear in Journal (JHEP)
JHEP 0908:017,2009
10.1088/1126-6708/2009/08/017
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze various models with an extra U(1) gauge symmetry in addition to the Standard Model (SM) gauge group at low energies, and impose limits on the mass of the neutral Z' boson, M_Z', predicted in all such models, and on the Z-Z' mixing angle, theta_ZZ'. The precision electroweak data strongly constrain theta_ZZ' to very small values and for most models we find lower limits on M_Z' of order 1 TeV. In one case we obtain a somewhat better fit than in the SM (although this is only marginally statistically significant) and here we find a weak upper limit at the 90% C.L.
[ { "created": "Fri, 12 Jun 2009 23:45:24 GMT", "version": "v1" }, { "created": "Fri, 19 Jun 2009 22:18:43 GMT", "version": "v2" }, { "created": "Thu, 2 Jul 2009 18:00:08 GMT", "version": "v3" } ]
2010-01-15
[ [ "Erler", "Jens", "" ], [ "Langacker", "Paul", "" ], [ "Munir", "Shoaib", "" ], [ "Rojas", "Eduardo", "" ] ]
We analyze various models with an extra U(1) gauge symmetry in addition to the Standard Model (SM) gauge group at low energies, and impose limits on the mass of the neutral Z' boson, M_Z', predicted in all such models, and on the Z-Z' mixing angle, theta_ZZ'. The precision electroweak data strongly constrain theta_ZZ' to very small values and for most models we find lower limits on M_Z' of order 1 TeV. In one case we obtain a somewhat better fit than in the SM (although this is only marginally statistically significant) and here we find a weak upper limit at the 90% C.L.
1807.10927
Renata Jora
Amir H. Fariborz and Renata Jora
Generalized linear sigma model with two glueballs
24 pages, version accepted for publication in Phys. Rev. D
Phys. Rev. D 98, 094032 (2018)
10.1103/PhysRevD.98.094032
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a generalized linear sigma model that includes both scalar and pseudoscalar glueballs in addition to a quark-antiquark as well as a four-quark chiral nonet. Utilizing the axial and trace anomalies of QCD (at the effective mesonic level), we aim to develope the most general structure of the Lagrangian which can be used to study the interaction of quarkonia with glueballs. We then study the effect of scalar glueball on the vacuum of the model by considering a decoupling limit in which the glueball fields are decoupled from quarkonia. This determines the properties of the pure scalar glueball and builds a practical foundation for determining the model parameters when the interactions are turned on.
[ { "created": "Sat, 28 Jul 2018 11:42:21 GMT", "version": "v1" }, { "created": "Thu, 25 Oct 2018 13:02:41 GMT", "version": "v2" }, { "created": "Thu, 25 Oct 2018 03:16:45 GMT", "version": "v3" } ]
2018-12-05
[ [ "Fariborz", "Amir H.", "" ], [ "Jora", "Renata", "" ] ]
We present a generalized linear sigma model that includes both scalar and pseudoscalar glueballs in addition to a quark-antiquark as well as a four-quark chiral nonet. Utilizing the axial and trace anomalies of QCD (at the effective mesonic level), we aim to develope the most general structure of the Lagrangian which can be used to study the interaction of quarkonia with glueballs. We then study the effect of scalar glueball on the vacuum of the model by considering a decoupling limit in which the glueball fields are decoupled from quarkonia. This determines the properties of the pure scalar glueball and builds a practical foundation for determining the model parameters when the interactions are turned on.
hep-ph/0208109
Jonathan R. Ellis
John Ellis (CERN)
Looking Back at the First Decade of 21st-Century High-Energy Physics
18 pages, 16 eps figures, uses ws-procs9x6.cls (included)
null
10.1142/9789812704917_0014
CERN-TH/2002-189
hep-ph
null
On the occasion of the Tenth Conference on String Phenomenology in 2011, I review the dramatic progress since 2002 in experimental tests of fundamental theoretical ideas. These include the discovery of (probably fermionic) extra dimensions at the LHC, the discovery of dark matter particles, observations of charged-lepton flavour violation, the debut of quantum gravity phenomenology and the emergence of space-time from the string soup.
[ { "created": "Mon, 12 Aug 2002 07:45:17 GMT", "version": "v1" } ]
2017-08-23
[ [ "Ellis", "John", "", "CERN" ] ]
On the occasion of the Tenth Conference on String Phenomenology in 2011, I review the dramatic progress since 2002 in experimental tests of fundamental theoretical ideas. These include the discovery of (probably fermionic) extra dimensions at the LHC, the discovery of dark matter particles, observations of charged-lepton flavour violation, the debut of quantum gravity phenomenology and the emergence of space-time from the string soup.
2404.05492
German Rodrigo
The LTD Collaboration, Selomit Ram\'irez-Uribe, Andr\'es E. Renter\'ia-Olivo, David F. Renter\'ia-Estrada, Jorge J. Mart\'inez de Lejarza, Prasanna K. Dhani, Leandro Cieri, Roger J. Hern\'andez-Pinto, German F. R. Sborlini, William J. Torres Bobadilla and Germ\'an Rodrigo
Vacuum amplitudes and time-like causal unitary in the loop-tree duality
11 pages, 6 figures
null
null
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the first proof-of-concept application to decay processes at higher perturbative orders of LTD causal unitary, a novel methodology that exploits the causal properties of vacuum amplitudes in the loop-tree duality (LTD) and is directly well-defined in the four physical dimensions of the space-time. The generation of loop- and tree-level contributions to the differential decay rates from a kernel multiloop vacuum amplitude is shown in detail, and explicit expressions are presented for selected processes that are suitable for a lightweight understanding of the method. Specifically, we provide a clear physical interpretation of the local cancellation of soft, collinear and unitary threshold singularities, and of the local renormalisation of ultraviolet singularities. The presentation is illustrated with numerical results that showcase the advantages of the method.
[ { "created": "Mon, 8 Apr 2024 13:12:38 GMT", "version": "v1" } ]
2024-04-09
[ [ "The LTD Collaboration", "", "" ], [ "Ramírez-Uribe", "Selomit", "" ], [ "Rentería-Olivo", "Andrés E.", "" ], [ "Rentería-Estrada", "David F.", "" ], [ "de Lejarza", "Jorge J. Martínez", "" ], [ "Dhani", "Prasanna K.", "" ], [ "Cieri", "Leandro", "" ], [ "Hernández-Pinto", "Roger J.", "" ], [ "Sborlini", "German F. R.", "" ], [ "Bobadilla", "William J. Torres", "" ], [ "Rodrigo", "Germán", "" ] ]
We present the first proof-of-concept application to decay processes at higher perturbative orders of LTD causal unitary, a novel methodology that exploits the causal properties of vacuum amplitudes in the loop-tree duality (LTD) and is directly well-defined in the four physical dimensions of the space-time. The generation of loop- and tree-level contributions to the differential decay rates from a kernel multiloop vacuum amplitude is shown in detail, and explicit expressions are presented for selected processes that are suitable for a lightweight understanding of the method. Specifically, we provide a clear physical interpretation of the local cancellation of soft, collinear and unitary threshold singularities, and of the local renormalisation of ultraviolet singularities. The presentation is illustrated with numerical results that showcase the advantages of the method.
1601.04291
Anish Ghoshal
Anish Ghoshal
On Electroweak Phase Transition and Di-photon Excess with a 750 GeV Scalar Resonance
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For successful electroweak baryogenesis to take place through the sphaleron process the universe needs to undergo a strong first order cosmological phase transition. While it does not occur in the Standard Model it becomes possible in the presence of extra scalars in BSM. One of these scalars can well be responsible for the recently observed diphoton excess in the CMS and ATLAS experiments in LHC. We study the Electroweak phase transition in a myriad of scalar models in this context.
[ { "created": "Sun, 17 Jan 2016 13:17:42 GMT", "version": "v1" } ]
2016-01-19
[ [ "Ghoshal", "Anish", "" ] ]
For successful electroweak baryogenesis to take place through the sphaleron process the universe needs to undergo a strong first order cosmological phase transition. While it does not occur in the Standard Model it becomes possible in the presence of extra scalars in BSM. One of these scalars can well be responsible for the recently observed diphoton excess in the CMS and ATLAS experiments in LHC. We study the Electroweak phase transition in a myriad of scalar models in this context.
2206.14790
Johann Usovitsch
Martijn Hidding, Johann Usovitsch
Feynman parameter integration through differential equations
null
null
null
UUITP-31/22,CERN-TH-2022-111
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We present a new method for numerically computing generic multi-loop Feynman integrals. The method relies on an iterative application of Feynman's trick for combining two propagators. Each application of Feynman's trick introduces a simplified Feynman integral topology which depends on a Feynman parameter that should be integrated over. For each integral family, we set up a system of differential equations which we solve in terms of a piecewise collection of generalized series expansions in the Feynman parameter. These generalized series expansions can be efficiently integrated term by term, and segment by segment. This approach leads to a fully algorithmic method for computing Feynman integrals from differential equations, which does not require the manual determination of boundary conditions. Furthermore, the most complicated topology that appears in the method often has less master integrals than the original one. We illustrate the strength of our method with a five-point two-loop integral family.
[ { "created": "Wed, 29 Jun 2022 17:45:57 GMT", "version": "v1" } ]
2022-06-30
[ [ "Hidding", "Martijn", "" ], [ "Usovitsch", "Johann", "" ] ]
We present a new method for numerically computing generic multi-loop Feynman integrals. The method relies on an iterative application of Feynman's trick for combining two propagators. Each application of Feynman's trick introduces a simplified Feynman integral topology which depends on a Feynman parameter that should be integrated over. For each integral family, we set up a system of differential equations which we solve in terms of a piecewise collection of generalized series expansions in the Feynman parameter. These generalized series expansions can be efficiently integrated term by term, and segment by segment. This approach leads to a fully algorithmic method for computing Feynman integrals from differential equations, which does not require the manual determination of boundary conditions. Furthermore, the most complicated topology that appears in the method often has less master integrals than the original one. We illustrate the strength of our method with a five-point two-loop integral family.
1911.06536
Ju-Jun Xie
He Zhou and Ju-Jun Xie
Role of the $\Lambda(1600)$ in the $K^-p \to \Lambda \pi^0\pi^0$ reaction
7 pages, 4 figures. Published version
Commun. Theor. Phys. 72 (2020) 045202
10.1088/1572-9494/ab6913
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Role of the $\Lambda(1600)$ is studied in the $K^- p \to \Lambda \pi^0 \pi^0$ reaction by using the effective Lagrangian approach near the threshold. We perform a calculation for the total and differential cross sections by considering the contributions from the $\Lambda(1600)$ and $\Lambda(1670)$ intermediate resonances decaying into $\pi^0 \Sigma^{*0}(1385)$ with $\Sigma^{*0}(1385)$ decaying into $\pi^0 \Lambda$. Besides, the non-resonance process from $u$-channel nucleon pole is also taken into account. With our model parameters, the current experimental data on the total cross sections of the $K^- p \to \Lambda \pi^0 \pi^0$ reaction can be well reproduced. It is shown that we really need the contribution from the $\Lambda(1600)$ with spin-parity $J^P = 1/2^+$, and that these measurements can be used to determine some of the properties of the $\Lambda(1600)$ resonance. Furthermore, we also plot the $\pi^0 \Lambda$ invariant mass distributions which could be tested by the future experimental measurements.
[ { "created": "Fri, 15 Nov 2019 09:43:22 GMT", "version": "v1" }, { "created": "Wed, 8 Apr 2020 08:20:58 GMT", "version": "v2" } ]
2020-04-09
[ [ "Zhou", "He", "" ], [ "Xie", "Ju-Jun", "" ] ]
Role of the $\Lambda(1600)$ is studied in the $K^- p \to \Lambda \pi^0 \pi^0$ reaction by using the effective Lagrangian approach near the threshold. We perform a calculation for the total and differential cross sections by considering the contributions from the $\Lambda(1600)$ and $\Lambda(1670)$ intermediate resonances decaying into $\pi^0 \Sigma^{*0}(1385)$ with $\Sigma^{*0}(1385)$ decaying into $\pi^0 \Lambda$. Besides, the non-resonance process from $u$-channel nucleon pole is also taken into account. With our model parameters, the current experimental data on the total cross sections of the $K^- p \to \Lambda \pi^0 \pi^0$ reaction can be well reproduced. It is shown that we really need the contribution from the $\Lambda(1600)$ with spin-parity $J^P = 1/2^+$, and that these measurements can be used to determine some of the properties of the $\Lambda(1600)$ resonance. Furthermore, we also plot the $\pi^0 \Lambda$ invariant mass distributions which could be tested by the future experimental measurements.
hep-ph/0203235
Jen-Chieh Peng
Jen-Chieh Peng
Status of Spin Physics - Experimental Summary
18 pages, 7 figures, Invited talk presented at the Third Circum-Pan-Pacific Symposium on High Energy Spin Physics held in Beijing, October, 2001
Int.J.Mod.Phys. A18 (2003) 1513-1530
10.1142/S0217751X03015015
null
hep-ph
null
The current status of spin physics experiments, based on talks presented at the Third Circum-Pan-Pacific Symposium on High Energy Spin Physics held in Beijing, 2001, is summarized in this article. Highlights of recent experimental results at SLAC, JLab, and DESY, as well as future plans at these facilities and at RHIC-spin are discussed.
[ { "created": "Mon, 25 Mar 2002 17:12:52 GMT", "version": "v1" } ]
2009-11-07
[ [ "Peng", "Jen-Chieh", "" ] ]
The current status of spin physics experiments, based on talks presented at the Third Circum-Pan-Pacific Symposium on High Energy Spin Physics held in Beijing, 2001, is summarized in this article. Highlights of recent experimental results at SLAC, JLab, and DESY, as well as future plans at these facilities and at RHIC-spin are discussed.
hep-ph/0002230
Christopher T. Hill
Christopher T. Hill
The Diffractive Quantum Limits of Particle Colliders
null
null
null
Fermilab-Pub-00/047-T; EFI-2000-6
hep-ph hep-ex physics.acc-ph
null
Quantum Mechanics places limits on achievable transverse beam spot sizes of particle accelerators. We estimate this limit for a linear collider to be \Delta x > \hbar c f/E\delta_0 where f is the final focal length, E the beam energy, and \delta_0 the intrinsic transverse Gaussian width of the electron wave-function. \delta_0 is determined in the phase space damping rings, and we find \delta_0 \approx \sqrt{\hbar c /eB} where B is the typical wiggler magnetic field strength in this system. For the NLC \delta_0 = 25 nm, and \Delta x = 0.06 nm, about two orders of magnitude smaller than the design goal. We can recover a crude estimate of the classical result when we include radiative relaxation effects. We also consider a synchrotron and obtain \Delta x > \sqrt{\hbar c f/E} = O(1.0) nm. We discuss formulation of quantum beam optics relevant to these issues.
[ { "created": "Tue, 22 Feb 2000 19:53:30 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2000 16:10:20 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hill", "Christopher T.", "" ] ]
Quantum Mechanics places limits on achievable transverse beam spot sizes of particle accelerators. We estimate this limit for a linear collider to be \Delta x > \hbar c f/E\delta_0 where f is the final focal length, E the beam energy, and \delta_0 the intrinsic transverse Gaussian width of the electron wave-function. \delta_0 is determined in the phase space damping rings, and we find \delta_0 \approx \sqrt{\hbar c /eB} where B is the typical wiggler magnetic field strength in this system. For the NLC \delta_0 = 25 nm, and \Delta x = 0.06 nm, about two orders of magnitude smaller than the design goal. We can recover a crude estimate of the classical result when we include radiative relaxation effects. We also consider a synchrotron and obtain \Delta x > \sqrt{\hbar c f/E} = O(1.0) nm. We discuss formulation of quantum beam optics relevant to these issues.
hep-ph/9601376
Alejandra Melfo
Gia Dvali, Alejandra Melfo and Goran Senjanovic
Nonrestoration of spontaneously broken P, CP and PQ at high temperature
22 pages, 3 figures, uses psfig. Replaced version with the Latex source
Phys.Rev. D54 (1996) 7857-7866
10.1103/PhysRevD.54.7857
SISSA Ref. 18/96/A
hep-ph astro-ph
null
The possibility of P and CP violation at high temperature in models where these symmetries are spontaneously broken is investigated. It is found that in minimal models that include singlet fields, high T nonrestoration is possible for a wide range of parameters of the theory, in particular in models of CP violation with a CP-odd Higgs field. The same holds true for the invisible axion version of the Peccei-Quinn mechanism. This can provide both a way out for the domain wall problem in these theories and the CP violation required for baryogenesis. In the case of spontaneous P violation it turns out that high T nonrestoration requires going beyond the minimal model.The results are shown to hold true when next-to-leading order effects are considered.
[ { "created": "Tue, 30 Jan 1996 19:39:48 GMT", "version": "v1" }, { "created": "Thu, 1 Feb 1996 13:18:11 GMT", "version": "v2" } ]
2009-10-28
[ [ "Dvali", "Gia", "" ], [ "Melfo", "Alejandra", "" ], [ "Senjanovic", "Goran", "" ] ]
The possibility of P and CP violation at high temperature in models where these symmetries are spontaneously broken is investigated. It is found that in minimal models that include singlet fields, high T nonrestoration is possible for a wide range of parameters of the theory, in particular in models of CP violation with a CP-odd Higgs field. The same holds true for the invisible axion version of the Peccei-Quinn mechanism. This can provide both a way out for the domain wall problem in these theories and the CP violation required for baryogenesis. In the case of spontaneous P violation it turns out that high T nonrestoration requires going beyond the minimal model.The results are shown to hold true when next-to-leading order effects are considered.
2106.10838
Sebasti\'an Urrutia Quiroga
Julia Harz, Michael J. Ramsey-Musolf, Tianyang Shen, Sebasti\'an Urrutia Quiroga
TeV-scale Lepton Number Violation: Connecting Leptogenesis, Neutrinoless Double Beta Decay, and Colliders
31 pages + appendix (5 pages), 16 figures, and 5 tables. v5: missing reference in TeX file
null
null
ACFI-T21-08, TUM-HEP-1346/21
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the context of TeV-scale lepton number violating (LNV) interactions, we illustrate the interplay between leptogenesis, neutrinoless double beta ($0\nu\beta\beta$) decay, and LNV searches at proton-proton colliders. Using a concrete model for illustration, we identify the parameter space where standard thermal leptogenesis is rendered unviable due to washout processes and show how $0\nu\beta\beta$ decay and $pp$ collisions provide complementary probes. We find that the new particle spectrum can have a decisive impact on the relative sensitivity of these two probes.
[ { "created": "Mon, 21 Jun 2021 03:58:38 GMT", "version": "v1" }, { "created": "Fri, 4 Feb 2022 19:00:01 GMT", "version": "v2" }, { "created": "Mon, 28 Feb 2022 16:52:39 GMT", "version": "v3" }, { "created": "Mon, 22 Jul 2024 16:12:47 GMT", "version": "v4" }, { "created": "Wed, 24 Jul 2024 17:22:56 GMT", "version": "v5" } ]
2024-07-25
[ [ "Harz", "Julia", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Shen", "Tianyang", "" ], [ "Quiroga", "Sebastián Urrutia", "" ] ]
In the context of TeV-scale lepton number violating (LNV) interactions, we illustrate the interplay between leptogenesis, neutrinoless double beta ($0\nu\beta\beta$) decay, and LNV searches at proton-proton colliders. Using a concrete model for illustration, we identify the parameter space where standard thermal leptogenesis is rendered unviable due to washout processes and show how $0\nu\beta\beta$ decay and $pp$ collisions provide complementary probes. We find that the new particle spectrum can have a decisive impact on the relative sensitivity of these two probes.
1903.06155
Johannes Bl\"umlein
J. Bl\"umlein, A. De Freitas, C.G. Raab and K. Sch\"onwald
The unpolarized two-loop massive pure singlet Wilson coefficients for deep-inelastic scattering
42, pages Latex, 8 Figures
null
10.1016/j.nuclphysb.2019.114659
DESY 19--038,DO--TH 18/25
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the massive two--loop pure singlet Wilson coefficients for heavy quark production in the unpolarized case analytically in the whole kinematic region and derive the threshold and asymptotic expansions. We also recalculate the corresponding massless two--loop Wilson coefficients. The complete expressions contain iterated integrals with elliptic letters. The contributing alphabets enlarge the Kummer-Poincar\'e letters by a series of square-root valued letters. A new class of iterated integrals, the Kummer-elliptic integrals, are introduced. For the structure functions $F_2$ and $F_L$ we also derive improved asymptotic representations adding power corrections. Numerical results are presented.
[ { "created": "Thu, 14 Mar 2019 17:54:20 GMT", "version": "v1" } ]
2019-06-12
[ [ "Blümlein", "J.", "" ], [ "De Freitas", "A.", "" ], [ "Raab", "C. G.", "" ], [ "Schönwald", "K.", "" ] ]
We calculate the massive two--loop pure singlet Wilson coefficients for heavy quark production in the unpolarized case analytically in the whole kinematic region and derive the threshold and asymptotic expansions. We also recalculate the corresponding massless two--loop Wilson coefficients. The complete expressions contain iterated integrals with elliptic letters. The contributing alphabets enlarge the Kummer-Poincar\'e letters by a series of square-root valued letters. A new class of iterated integrals, the Kummer-elliptic integrals, are introduced. For the structure functions $F_2$ and $F_L$ we also derive improved asymptotic representations adding power corrections. Numerical results are presented.
0801.1490
Vali Bashiry
V. Bashiry
CP-Conserving Unparticle Phase Effects on the Unpolarized and Polarized Direct CP Asymmetry in $b \to d \ell^+\ell^-$ Transition
10 figures, PRD Published version
Phys.Rev.D77:096005,2008
10.1103/PhysRevD.77.096005
null
hep-ph
null
We examine the unparticle CP-conserving phase effects on the direct CP asymmetry for both polarized and unpolarized lepton in the inclusive $b\to d \ell^+ \ell^-$ transition, where the flavor changing neutral currents are forbidden at tree level but are induced by one-loop penguin diagrams. The averaged polarized and unpolarized CP asymmetries depict strong dependency on the unparticle parameters. In particular, a sizable discrepancy corresponding to the standard model is achieved when the scale dimension value is $1<d_{\UP}< 2$. We see that the unparticle stuff significantly enhances, suppresses or changes the sign of the CP asymmetry depending on the definite value of the scaling dimension $d_{\UP}$. Especially, when $d_{\UP}\sim 1.1$ the CP asymmetries vanish.
[ { "created": "Wed, 9 Jan 2008 19:31:21 GMT", "version": "v1" }, { "created": "Wed, 14 May 2008 05:01:52 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bashiry", "V.", "" ] ]
We examine the unparticle CP-conserving phase effects on the direct CP asymmetry for both polarized and unpolarized lepton in the inclusive $b\to d \ell^+ \ell^-$ transition, where the flavor changing neutral currents are forbidden at tree level but are induced by one-loop penguin diagrams. The averaged polarized and unpolarized CP asymmetries depict strong dependency on the unparticle parameters. In particular, a sizable discrepancy corresponding to the standard model is achieved when the scale dimension value is $1<d_{\UP}< 2$. We see that the unparticle stuff significantly enhances, suppresses or changes the sign of the CP asymmetry depending on the definite value of the scaling dimension $d_{\UP}$. Especially, when $d_{\UP}\sim 1.1$ the CP asymmetries vanish.
0909.3521
A. Gynther
A. Gynther, A. Kurkela and A. Vuorinen
The N_f^3 g^6 term in the pressure of hot QCD
9 pages, 2 figures, revtex, v2: minor modifications and additional references
Phys.Rev.D80:096002,2009
10.1103/PhysRevD.80.096002
CERN-PH-TH-2009-172, TUW-09-14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the first independent part of the g^6 coefficient in the weak coupling expansion of the QCD pressure at high temperatures, the one proportional to the maximal power of the number of quark flavors N_f. In addition to introducing and developing computational methods that can be used in evaluating other parts of the expansion, our calculation provides a result that becomes dominant in the limit of large N_f and a fixed effective coupling g_{eff}^2 = g^2 N_f/2.
[ { "created": "Mon, 21 Sep 2009 09:37:17 GMT", "version": "v1" }, { "created": "Fri, 25 Sep 2009 09:59:15 GMT", "version": "v2" } ]
2010-06-22
[ [ "Gynther", "A.", "" ], [ "Kurkela", "A.", "" ], [ "Vuorinen", "A.", "" ] ]
We determine the first independent part of the g^6 coefficient in the weak coupling expansion of the QCD pressure at high temperatures, the one proportional to the maximal power of the number of quark flavors N_f. In addition to introducing and developing computational methods that can be used in evaluating other parts of the expansion, our calculation provides a result that becomes dominant in the limit of large N_f and a fixed effective coupling g_{eff}^2 = g^2 N_f/2.
hep-ph/0308266
Ira Z. Rothstein
Ira Z. Rothstein
TASI Lectures on Effective Field Theories
90 pages, typos fixed
null
null
null
hep-ph
null
These notes are a written version of a set of lectures given at TASI-02 on the topic of effective field theories. They are meant as an introduction to some of the latest techniques and applications in the field.
[ { "created": "Tue, 26 Aug 2003 23:34:06 GMT", "version": "v1" }, { "created": "Mon, 9 Feb 2004 22:39:08 GMT", "version": "v2" } ]
2007-05-23
[ [ "Rothstein", "Ira Z.", "" ] ]
These notes are a written version of a set of lectures given at TASI-02 on the topic of effective field theories. They are meant as an introduction to some of the latest techniques and applications in the field.
hep-ph/0208187
Stefan Kretzer
S. Kretzer (Michigan State University), M.H. Reno (University of Iowa)
Tau neutrino deep inelastic charged current interactions
28 pages, 10 figures
Phys.Rev. D66 (2002) 113007
10.1103/PhysRevD.66.113007
null
hep-ph
null
The nu_mu -> nu_tau oscillation hypothesis will be tested through nu_tau production of tau in underground neutrino telescopes as well as long-baseline experiments. We provide the full QCD framework for the evaluation of tau neutrino deep inelastic charged current (CC) cross sections, including next-leading-order (NLO) corrections, charm production, tau threshold, and target mass effects in the collinear approximation. We investigate the violation of the Albright-Jarlskog relations for the structure functions F_4,5 which occur only in heavy lepton (tau) scattering. Integrated CC cross sections are evaluated naively over the full phase space and with the inclusion of DIS kinematic cuts. Uncertainties in our evaluation based on scale dependence, PDF errors and the interplay between kinematic and dynamical power corrections are discussed and/or quantified.
[ { "created": "Wed, 21 Aug 2002 00:18:28 GMT", "version": "v1" } ]
2009-11-07
[ [ "Kretzer", "S.", "", "Michigan State University" ], [ "Reno", "M. H.", "", "University of Iowa" ] ]
The nu_mu -> nu_tau oscillation hypothesis will be tested through nu_tau production of tau in underground neutrino telescopes as well as long-baseline experiments. We provide the full QCD framework for the evaluation of tau neutrino deep inelastic charged current (CC) cross sections, including next-leading-order (NLO) corrections, charm production, tau threshold, and target mass effects in the collinear approximation. We investigate the violation of the Albright-Jarlskog relations for the structure functions F_4,5 which occur only in heavy lepton (tau) scattering. Integrated CC cross sections are evaluated naively over the full phase space and with the inclusion of DIS kinematic cuts. Uncertainties in our evaluation based on scale dependence, PDF errors and the interplay between kinematic and dynamical power corrections are discussed and/or quantified.
hep-ph/0111025
Jean-Rene Cudell
J.R. Cudell, K. Kang, V.V. Ezhela, Yu.V. Kuyanov, S.B. Lugovsky, N.P. Tkachenko, P. Gauron and B. Nicolescu
New measures of the quality and of the reliability of fits applied to forward hadronic data at t=0
7 pages, presented by J.R. Cudell on behalf of the COMPETE collaboration at the 6th workshop on non-perturbative QCD, American University of Paris, 5-9 June 2001
null
10.1142/9789812778352_0016
null
hep-ph
null
We develop five new statistical measures of the quality of fits, which we combine with the usual confidence level to determine the models which fit best all available data for total cross sections and for the real part of the forward hadronic amplitude.
[ { "created": "Fri, 2 Nov 2001 13:53:54 GMT", "version": "v1" } ]
2017-08-23
[ [ "Cudell", "J. R.", "" ], [ "Kang", "K.", "" ], [ "Ezhela", "V. V.", "" ], [ "Kuyanov", "Yu. V.", "" ], [ "Lugovsky", "S. B.", "" ], [ "Tkachenko", "N. P.", "" ], [ "Gauron", "P.", "" ], [ "Nicolescu", "B.", "" ] ]
We develop five new statistical measures of the quality of fits, which we combine with the usual confidence level to determine the models which fit best all available data for total cross sections and for the real part of the forward hadronic amplitude.
hep-ph/0103333
Xavier Calmet
Xavier Calmet and Harald Fritzsch (Munich U.)
Electroweak D-Waves
15 pages
Phys.Lett. B526 (2002) 90-96
10.1016/S0370-2693(01)01471-X
LMU 01/05
hep-ph
null
We consider phenomenological implications of a model recently proposed for the electroweak interactions based on a SU(2)_L confining theory. We concentrate on the production of excited states of the electroweak bosons at future colliders and we consider their contribution to the reaction W^+ + W^- \to W^+ + W^-. We expect large deviations from the standard model in the TeV region.
[ { "created": "Fri, 30 Mar 2001 11:29:51 GMT", "version": "v1" } ]
2009-11-07
[ [ "Calmet", "Xavier", "", "Munich U." ], [ "Fritzsch", "Harald", "", "Munich U." ] ]
We consider phenomenological implications of a model recently proposed for the electroweak interactions based on a SU(2)_L confining theory. We concentrate on the production of excited states of the electroweak bosons at future colliders and we consider their contribution to the reaction W^+ + W^- \to W^+ + W^-. We expect large deviations from the standard model in the TeV region.
hep-ph/0111292
Axel de la Macorra
A. de la Macorra
Quintessence Unification Models from Non-Abelian Gauge Dynamics
18 pages, LaTeX, 3 figures, minor changes, subsections added (for presentation purpose)
JHEP 0301:033,2003
10.1088/1126-6708/2003/01/033
null
hep-ph astro-ph hep-th
null
We show that the condensates of a non-abelian gauge group, unified with the standard model gauge groups, can parameterize the present day cosmological constant and play the role of quintessence. The models agree with SN1a and recent CMB analysis. These models have {\it no free} parameters. Even the initial energy density at the unification scale and at the condensation scale are fixed by the number of degrees of freedom of the gauge group (i.e. by $N_c, N_f$). The values of $N_c, N_f$ are determined by imposing gauge coupling unification and the number of models is quite limited. Using Affleck-Dine-Seiberg superpotential one obtains a scalar potential $V=\Lm_c^{4+n}\phi^{-n}$. Models with $2<n<4.27$ or equivalently $2\times 10^{-2} GeV < \Lm_c < 6 \times 10^3 GeV$ do not satisfy the unification constrain. In fact, there are only three models and they have an inverse power potential with $6/11 \leq n \leq 2/3$. Imposing primordial nucleosynthesis bounds the preferred model has $N_c=3, N_f=6$, with $n=2/3$, a condensation scale $\Lm_c=4.2\times 10^{-8} GeV$ and $\wpo=-0.90$ with an average value $\weff=-0.93$. Notice that the tracker solution is not a good approximation since it has $w_{tr}=-\fr{2}{n+2}=-0.75$ for $n=2/3$. We study the evolution of all fields from the unification scale and we calculate the relevant cosmological quantities. We also discuss the supersymmetry breaking mechanism which is relevant for these models.
[ { "created": "Thu, 22 Nov 2001 21:01:23 GMT", "version": "v1" }, { "created": "Wed, 15 May 2002 23:11:53 GMT", "version": "v2" }, { "created": "Tue, 22 Oct 2002 01:04:42 GMT", "version": "v3" } ]
2014-11-17
[ [ "de la Macorra", "A.", "" ] ]
We show that the condensates of a non-abelian gauge group, unified with the standard model gauge groups, can parameterize the present day cosmological constant and play the role of quintessence. The models agree with SN1a and recent CMB analysis. These models have {\it no free} parameters. Even the initial energy density at the unification scale and at the condensation scale are fixed by the number of degrees of freedom of the gauge group (i.e. by $N_c, N_f$). The values of $N_c, N_f$ are determined by imposing gauge coupling unification and the number of models is quite limited. Using Affleck-Dine-Seiberg superpotential one obtains a scalar potential $V=\Lm_c^{4+n}\phi^{-n}$. Models with $2<n<4.27$ or equivalently $2\times 10^{-2} GeV < \Lm_c < 6 \times 10^3 GeV$ do not satisfy the unification constrain. In fact, there are only three models and they have an inverse power potential with $6/11 \leq n \leq 2/3$. Imposing primordial nucleosynthesis bounds the preferred model has $N_c=3, N_f=6$, with $n=2/3$, a condensation scale $\Lm_c=4.2\times 10^{-8} GeV$ and $\wpo=-0.90$ with an average value $\weff=-0.93$. Notice that the tracker solution is not a good approximation since it has $w_{tr}=-\fr{2}{n+2}=-0.75$ for $n=2/3$. We study the evolution of all fields from the unification scale and we calculate the relevant cosmological quantities. We also discuss the supersymmetry breaking mechanism which is relevant for these models.
hep-ph/0601076
Thomas Heinzl
T. Heinzl, B. Liesfeld, K.-U. Amthor, H. Schwoerer, R. Sauerbrey and A. Wipf
On the Observation of Vacuum Birefringence
4 pages, 4 figures
Opt.Commun. 267 (2006) 318-321
10.1016/j.optcom.2006.06.053
null
hep-ph hep-ex
null
We suggest an experiment to observe vacuum birefringence induced by intense laser fields. A high-intensity laser pulse is focused to ultra-relativistic intensity and polarizes the vacuum which then acts like a birefringent medium. The latter is probed by a linearly polarized x-ray pulse. We calculate the resulting ellipticity signal within strong-field QED assuming Gaussian beams. The laser technology required for detecting the signal will be available within the next three years.
[ { "created": "Tue, 10 Jan 2006 15:46:36 GMT", "version": "v1" } ]
2009-11-11
[ [ "Heinzl", "T.", "" ], [ "Liesfeld", "B.", "" ], [ "Amthor", "K. -U.", "" ], [ "Schwoerer", "H.", "" ], [ "Sauerbrey", "R.", "" ], [ "Wipf", "A.", "" ] ]
We suggest an experiment to observe vacuum birefringence induced by intense laser fields. A high-intensity laser pulse is focused to ultra-relativistic intensity and polarizes the vacuum which then acts like a birefringent medium. The latter is probed by a linearly polarized x-ray pulse. We calculate the resulting ellipticity signal within strong-field QED assuming Gaussian beams. The laser technology required for detecting the signal will be available within the next three years.
1907.07728
Rahul Srivastava
Sanjoy Mandal, Nicol\'as Rojas, Rahul Srivastava, Jos\'e W. F. Valle
Dark matter as the origin of neutrino mass in the inverse seesaw mechanism
23 pages, 5 tables, 12 figures. Substantially expanded version, including detailed phenomenology discussion. Model and conclusions unchanged. New author added. Version matches the published version
Phys. Lett. B, 821, (2021), 136609
10.1016/j.physletb.2021.136609
IFIC/19-XXX
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose that neutrino masses are "seeded" by a dark sector within the inverse seesaw mechanism. This way we have a new, "hidden", variant of the scotogenic scenario for radiative neutrino masses. We discuss both explicit and dynamical lepton number violation. In addition to invisible Higgs decays with majoron emission, we discuss in detail the pheneomenolgy of dark matter, as well as the novel features associated to charged lepton flavour violation, and neutrino physics.
[ { "created": "Wed, 17 Jul 2019 19:16:38 GMT", "version": "v1" }, { "created": "Tue, 7 Sep 2021 11:50:00 GMT", "version": "v2" } ]
2021-09-08
[ [ "Mandal", "Sanjoy", "" ], [ "Rojas", "Nicolás", "" ], [ "Srivastava", "Rahul", "" ], [ "Valle", "José W. F.", "" ] ]
We propose that neutrino masses are "seeded" by a dark sector within the inverse seesaw mechanism. This way we have a new, "hidden", variant of the scotogenic scenario for radiative neutrino masses. We discuss both explicit and dynamical lepton number violation. In addition to invisible Higgs decays with majoron emission, we discuss in detail the pheneomenolgy of dark matter, as well as the novel features associated to charged lepton flavour violation, and neutrino physics.
hep-ph/0306081
Vladimir Sauli
Vladimir Sauli
Running coupling and fermion mass in strong coupling QED
23 pages, 4 figures, v4: revised and extended version, one introductory section added
J.Phys.G30:739-758,2004
10.1088/0954-3899/30/6/005
null
hep-ph
null
Simple toy model is used in order to exhibit the technique of extracting the non-perturbative information about Green's functions in Minkowski space. The effective charge and the dynamical electron mass are calculated in strong coupling 3+1 QED by solving the coupled Dyson-Schwinger equations for electron and photon propagators. The minimal Ball-Chiu vertex was used for simplicity and we impose the Landau gauge fixing on QED action. The solution obtained separately in Euclidean and Minkowski space were compared, the latter one was extracted with the help of spectral technique.
[ { "created": "Tue, 10 Jun 2003 13:04:36 GMT", "version": "v1" }, { "created": "Fri, 1 Aug 2003 15:12:31 GMT", "version": "v2" }, { "created": "Tue, 14 Oct 2003 16:49:54 GMT", "version": "v3" }, { "created": "Wed, 28 Jan 2004 12:32:05 GMT", "version": "v4" } ]
2008-11-26
[ [ "Sauli", "Vladimir", "" ] ]
Simple toy model is used in order to exhibit the technique of extracting the non-perturbative information about Green's functions in Minkowski space. The effective charge and the dynamical electron mass are calculated in strong coupling 3+1 QED by solving the coupled Dyson-Schwinger equations for electron and photon propagators. The minimal Ball-Chiu vertex was used for simplicity and we impose the Landau gauge fixing on QED action. The solution obtained separately in Euclidean and Minkowski space were compared, the latter one was extracted with the help of spectral technique.
1308.3158
Xiang Liu
Xiao Wang, Yuan Sun, Dian-Yong Chen, Xiang Liu and Takayuki Matsuki
Simulating the charged charmoniumlike structure $Z_c(4025)$
5 pages, 4 figures. Title changed and more discussed added. Accepted by Eur. Phys. J. C
Eur. Phys. J. C 74, 2761 (2014)
10.1140/epjc/s10052-014-2761-2
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by recent observation of charged charmoniumlike structure $Z_c(4025)$, we explore the $Y(4260)\to (D^*\bar{D}^*)^- \pi^+$ decay through the initial-single-pion-emission mechanism, where the $D^*\bar{D}^*\to D^*\bar{D}^*$ interaction is studied by the ladder approximation including a non-interacting case. Our calculation of the differential decay width for $Y(4260)\to (D^*\bar{D}^*)^- \pi^+$ indicates that a charged enhancement structure around $D^*\bar{D}^*$ appears in the $D^*\bar{D}^*$ invariant mass spectrum for this process, which can correspond to newly observed $Z_c(4025)$ structure.
[ { "created": "Wed, 14 Aug 2013 15:43:41 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2014 04:58:20 GMT", "version": "v2" } ]
2014-02-17
[ [ "Wang", "Xiao", "" ], [ "Sun", "Yuan", "" ], [ "Chen", "Dian-Yong", "" ], [ "Liu", "Xiang", "" ], [ "Matsuki", "Takayuki", "" ] ]
Inspired by recent observation of charged charmoniumlike structure $Z_c(4025)$, we explore the $Y(4260)\to (D^*\bar{D}^*)^- \pi^+$ decay through the initial-single-pion-emission mechanism, where the $D^*\bar{D}^*\to D^*\bar{D}^*$ interaction is studied by the ladder approximation including a non-interacting case. Our calculation of the differential decay width for $Y(4260)\to (D^*\bar{D}^*)^- \pi^+$ indicates that a charged enhancement structure around $D^*\bar{D}^*$ appears in the $D^*\bar{D}^*$ invariant mass spectrum for this process, which can correspond to newly observed $Z_c(4025)$ structure.
hep-ph/0103275
Dmitri Ivanov
V.M. Braun, D.Yu. Ivanov, A. Schaefer, L. Szymanowski
QCD factorization for the pion diffractive dissociation to two jets
Original version from 9 April restored
Phys.Lett. B509 (2001) 43-52
10.1016/S0370-2693(01)00554-8
null
hep-ph
null
We calculate the cross section of a pion diffraction dissociation in two jets with large transverse momenta originating from a hard gluon exchange between the pion constituents. To the leading logarithmic accuracy (in energy), the contribution coming from small transverse separations between the quark and the antiquark in the pion acquires the expected factorized form, the longitudinal momentum distribution of the jets being proportional to the pion distribution amplitude. The hard gluon exchange can in this case be considered as a part of the unintegrated gluon distribution. Beyond the leading logarithms (in energy) this proportionality does not hold. Moreover, the collinear factorization appears to be broken by the end-point singularities. Remarkably enough, the longitudinal momentum distribution of the jets for the non-factorizable contribution is calculable, and turns out to be the same as for the factorizable contribution with the asymptotic pion distribution amplitude.
[ { "created": "Mon, 26 Mar 2001 18:06:07 GMT", "version": "v1" }, { "created": "Mon, 9 Apr 2001 10:12:28 GMT", "version": "v2" }, { "created": "Thu, 24 May 2001 15:58:12 GMT", "version": "v3" }, { "created": "Thu, 9 Aug 2001 12:24:25 GMT", "version": "v4" } ]
2009-11-07
[ [ "Braun", "V. M.", "" ], [ "Ivanov", "D. Yu.", "" ], [ "Schaefer", "A.", "" ], [ "Szymanowski", "L.", "" ] ]
We calculate the cross section of a pion diffraction dissociation in two jets with large transverse momenta originating from a hard gluon exchange between the pion constituents. To the leading logarithmic accuracy (in energy), the contribution coming from small transverse separations between the quark and the antiquark in the pion acquires the expected factorized form, the longitudinal momentum distribution of the jets being proportional to the pion distribution amplitude. The hard gluon exchange can in this case be considered as a part of the unintegrated gluon distribution. Beyond the leading logarithms (in energy) this proportionality does not hold. Moreover, the collinear factorization appears to be broken by the end-point singularities. Remarkably enough, the longitudinal momentum distribution of the jets for the non-factorizable contribution is calculable, and turns out to be the same as for the factorizable contribution with the asymptotic pion distribution amplitude.
hep-ph/0401218
Vicente Vento
Vicente Vento
The scalar glueball spectrum
11 pages: New title, figure, table and a more detailed comparison with experiments
Phys.Rev.D73:054006,2006
10.1103/PhysRevD.73.054006
null
hep-ph
null
We discuss scenarios for scalar glueballs using arguments based on sum rules, spectral decomposition, the $\frac{1}{N_c}$ approximation, the scales of the strong interaction and the topology of the flux tubes. We analyze the phenomenological support of those scenarios and their observational implications. Our investigations hint a rich low lying glueball spectrum.
[ { "created": "Tue, 27 Jan 2004 17:30:04 GMT", "version": "v1" }, { "created": "Wed, 14 Apr 2004 16:12:57 GMT", "version": "v2" }, { "created": "Wed, 1 Jun 2005 09:45:44 GMT", "version": "v3" } ]
2008-11-26
[ [ "Vento", "Vicente", "" ] ]
We discuss scenarios for scalar glueballs using arguments based on sum rules, spectral decomposition, the $\frac{1}{N_c}$ approximation, the scales of the strong interaction and the topology of the flux tubes. We analyze the phenomenological support of those scenarios and their observational implications. Our investigations hint a rich low lying glueball spectrum.
hep-ph/0605315
Taizan Watari
Radu Tatar and Taizan Watari
A Stable Proton without R-Parity--Implications for the LSP--
13 pages, including 3 figures
Phys.Lett.B646:258-264,2007
10.1016/j.physletb.2007.01.020
LTH 705, UCB-PTH-06/08, LBNL-60200
hep-ph
null
The proton decays too rapidly in supersymmetric theories if a dimension-4 operator \bar{5}.10.\bar{5} exists in the superpotential. The conventional idea is to impose the R-parity to kill this operator with a stable lightest supersymmetry particle (LSP) as a direct consequence. However, the SUSY-zero mechanism is also able to kill the operator without an unbroken R-parity. In this article, we provide a firm theoretical justification for the absence of the dimension-4 proton decay operator under the SUSY-zero mechanism, by using some input from string theory. The LSP may be unstable without the R-parity and, indeed, some dimension-5 R-parity violating operators may be generated in effective theories. This suggests that the dark matter is an axion in this string theory inspired model. An insight on the SUSY-zero mechanism is also obtained.
[ { "created": "Mon, 29 May 2006 15:01:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Tatar", "Radu", "" ], [ "Watari", "Taizan", "" ] ]
The proton decays too rapidly in supersymmetric theories if a dimension-4 operator \bar{5}.10.\bar{5} exists in the superpotential. The conventional idea is to impose the R-parity to kill this operator with a stable lightest supersymmetry particle (LSP) as a direct consequence. However, the SUSY-zero mechanism is also able to kill the operator without an unbroken R-parity. In this article, we provide a firm theoretical justification for the absence of the dimension-4 proton decay operator under the SUSY-zero mechanism, by using some input from string theory. The LSP may be unstable without the R-parity and, indeed, some dimension-5 R-parity violating operators may be generated in effective theories. This suggests that the dark matter is an axion in this string theory inspired model. An insight on the SUSY-zero mechanism is also obtained.
2301.07089
Valery Telnov
K.I. Beloborodov (1 and 2), T.A. Kharlamova (1 and 2), V.I. Telnov (1 and 2) ((1) Budker Institute of Nuclear Physics, Novosibirsk, Russia, (2) Novosibirsk State University, Novosibirsk, Russia)
Problems of studying $\gamma \gamma \to \gamma\gamma$ scattering at $e^+e^-$ and $\gamma\gamma$ colliders
null
null
null
null
hep-ph hep-ex physics.acc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The process of elastic scattering of photons (light-by-light scattering) attracts a lot of attention in the last years. It goes via the loop and all charged particles contributes to its cross section. Theoretical prediction of the cross section have existed for more than half a century, there are various accelerators with real and virtual photons, but only recently this process was discovered at the LHC in ion-ion collisions. Hopes for further study of this process are associated with high-luminosity $e^+e^-$ colliders (SuperKEKb, FCC, ILC, CLIC) and gamma-gamma colliders based on the Compton scattering of laser photons on electrons. In this article, we show that there is very serious background processes when the final pair of photons is created in the annihilation of real and virtual $e^+$ and $e^-$, and the remaining products fly away from the detector at small angles.
[ { "created": "Tue, 17 Jan 2023 18:54:53 GMT", "version": "v1" } ]
2023-01-18
[ [ "Beloborodov", "K. I.", "", "1 and 2" ], [ "Kharlamova", "T. A.", "", "1 and 2" ], [ "Telnov", "V. I.", "", "1\n and 2" ] ]
The process of elastic scattering of photons (light-by-light scattering) attracts a lot of attention in the last years. It goes via the loop and all charged particles contributes to its cross section. Theoretical prediction of the cross section have existed for more than half a century, there are various accelerators with real and virtual photons, but only recently this process was discovered at the LHC in ion-ion collisions. Hopes for further study of this process are associated with high-luminosity $e^+e^-$ colliders (SuperKEKb, FCC, ILC, CLIC) and gamma-gamma colliders based on the Compton scattering of laser photons on electrons. In this article, we show that there is very serious background processes when the final pair of photons is created in the annihilation of real and virtual $e^+$ and $e^-$, and the remaining products fly away from the detector at small angles.
1005.4684
Min-Seok Seo
Jihn E. Kim and Min-Seok Seo
Quark and lepton mixing angles with a dodeca-symmetry
15 pages, 2 figures
JHEP 1102:097,2011
10.1007/JHEP02(2011)097
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discrete symmetry D_12 at the electroweak scale is used to fix the quark and lepton mixing angles. At the leading order, the Cabbibo angle theta_C is 15^o, and the PMNS matrix is of a bi-dodeca-mixing form giving the Solar-neutrino angle theta_sol=30^o. Thus, there results the relation theta_sol+theta_C ~ 45^o. Out of discrete vacua, a certain vacuum is chosen for this assignment to be consistent with the dodeca-symmetry. A shift of theta_C from 15^o to 13.14^o might arise from a small breaking of the dodeca-symmetry. The spontaneous breaking leading to the required electroweak vacuum is made possible by introducing an additional parity in an effective field approach or by realizing the electroweak dodeca-symmetry explicitly at a high energy scale. At the vacuum we chose Arg.Det.M_q is nonzero, and hence a solution of the strong CP problem invites a very light axion at a high energy scale. We also comment how the next level corrections can fit the mixing angles to the observed values.
[ { "created": "Tue, 25 May 2010 20:01:17 GMT", "version": "v1" }, { "created": "Sat, 26 Feb 2011 07:35:11 GMT", "version": "v2" } ]
2011-03-01
[ [ "Kim", "Jihn E.", "" ], [ "Seo", "Min-Seok", "" ] ]
The discrete symmetry D_12 at the electroweak scale is used to fix the quark and lepton mixing angles. At the leading order, the Cabbibo angle theta_C is 15^o, and the PMNS matrix is of a bi-dodeca-mixing form giving the Solar-neutrino angle theta_sol=30^o. Thus, there results the relation theta_sol+theta_C ~ 45^o. Out of discrete vacua, a certain vacuum is chosen for this assignment to be consistent with the dodeca-symmetry. A shift of theta_C from 15^o to 13.14^o might arise from a small breaking of the dodeca-symmetry. The spontaneous breaking leading to the required electroweak vacuum is made possible by introducing an additional parity in an effective field approach or by realizing the electroweak dodeca-symmetry explicitly at a high energy scale. At the vacuum we chose Arg.Det.M_q is nonzero, and hence a solution of the strong CP problem invites a very light axion at a high energy scale. We also comment how the next level corrections can fit the mixing angles to the observed values.
2012.12579
Andrea Gallo Rosso
A. Gallo Rosso
Supernova neutrino fluxes in HALO-1kT, Super-Kamiokande, and JUNO
Revised model 9.6 solar masses. Figures and tables updated, results unchanged
JCAP06(2021)046
10.1088/1475-7516/2021/06/046
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When the next galactic core-collapse supernova occurs, we must be ready to obtain as much information as possible. Although many present and future detectors are well equipped to detect $\overline{\nu}_{\mathrm{e}}$ and $\nu_x$ neutrinos, the detection of the $\nu_{\mathrm{e}}$ species presents the biggest challenges. We assess the impact that a 1 ktonne lead-based detector, such as HALO-1kT, can have in constraining electron neutrino time-integrated fluxes. The study involves the detector taken alone as well as when combined with massive $\overline{\nu}_{\mathrm{e}}$-sensitive detectors such as Super-Kamiokande and JUNO. We find that HALO-1kT alone is not able to strongly constrain the emission parameters. When combined with other detectors, however, the orthogonal information might be helpful in improving the $\nu_{\mathrm{e}}$ total emitted energy and mean energy accuracy, up to about $50\%$, if no other $\nu_{\mathrm{e}}$-sensitive channel is implemented. A discussion on the reconstruction of $\overline{\nu}_{\mathrm{e}}$ and $\nu_x$ species, as well as the total emitted energy, is also presented.
[ { "created": "Wed, 23 Dec 2020 10:09:57 GMT", "version": "v1" }, { "created": "Wed, 30 Jun 2021 12:42:27 GMT", "version": "v2" } ]
2021-07-01
[ [ "Rosso", "A. Gallo", "" ] ]
When the next galactic core-collapse supernova occurs, we must be ready to obtain as much information as possible. Although many present and future detectors are well equipped to detect $\overline{\nu}_{\mathrm{e}}$ and $\nu_x$ neutrinos, the detection of the $\nu_{\mathrm{e}}$ species presents the biggest challenges. We assess the impact that a 1 ktonne lead-based detector, such as HALO-1kT, can have in constraining electron neutrino time-integrated fluxes. The study involves the detector taken alone as well as when combined with massive $\overline{\nu}_{\mathrm{e}}$-sensitive detectors such as Super-Kamiokande and JUNO. We find that HALO-1kT alone is not able to strongly constrain the emission parameters. When combined with other detectors, however, the orthogonal information might be helpful in improving the $\nu_{\mathrm{e}}$ total emitted energy and mean energy accuracy, up to about $50\%$, if no other $\nu_{\mathrm{e}}$-sensitive channel is implemented. A discussion on the reconstruction of $\overline{\nu}_{\mathrm{e}}$ and $\nu_x$ species, as well as the total emitted energy, is also presented.
hep-ph/9410220
Kenzo Inoue
Kenzo Inoue
Generations of Quarks and Leptons from Noncompact Horizontal Symmetry
22 pages, e-mail: inoue@yukawa.kyoto-u.ac.jp , Plain Tex, YITP/K-1089
Prog.Theor.Phys. 93 (1995) 403-416
10.1143/PTP.93.403
null
hep-ph
null
The three chiral generations of quarks and leptons may be generated through a spontaneous breakdown of the noncompact horizontal gauge symmetry $G_{H}$ which governs, together with the standard gauge symmetry ${SU(3) \times SU(2) \times U(1)}$, the world in a vectorlike manner. In a framework of supersymmetric theory, the simplest choice ${G_{H}=SU(1,1)}$ works quite well for this scenario in which quarks, leptons and Higgses belong to infinite dimensional unitary representation of $SU(1,1)$. The relevance of the scenario to the hierarchical structure of their Yukawa coupling matrices are discussed.
[ { "created": "Wed, 5 Oct 1994 01:07:15 GMT", "version": "v1" }, { "created": "Wed, 12 Oct 1994 03:36:18 GMT", "version": "v2" } ]
2009-10-28
[ [ "Inoue", "Kenzo", "" ] ]
The three chiral generations of quarks and leptons may be generated through a spontaneous breakdown of the noncompact horizontal gauge symmetry $G_{H}$ which governs, together with the standard gauge symmetry ${SU(3) \times SU(2) \times U(1)}$, the world in a vectorlike manner. In a framework of supersymmetric theory, the simplest choice ${G_{H}=SU(1,1)}$ works quite well for this scenario in which quarks, leptons and Higgses belong to infinite dimensional unitary representation of $SU(1,1)$. The relevance of the scenario to the hierarchical structure of their Yukawa coupling matrices are discussed.
hep-ph/0406082
Volodymyr Magas
L.P. Csernai, V.K. Magas, E. Molnar, A. Nyiri and K. Tamosiunas
Freeze Out and the Boltzmann Transport Equation
More explanations about the Modified Boltzmann Transport Equation are added. 5 pages, 1 figure. Please note that there is a more detailed paper on the Modified Boltzmann Transport Equation published in the ArXiv: hep-ph/0502185
null
null
null
hep-ph
null
Recently several works have appeared in the literature that addressed the problem of Freeze Out in energetic heavy ion reaction and aimed for a description based on the Boltzmann Transport Equation (BTE). In this paper we develop a dynamical Freeze-Out description, starting from the BTE, pointing out the basic limitations of the BTE approach, and the points where the BTE approach should be modified.
[ { "created": "Mon, 7 Jun 2004 15:39:09 GMT", "version": "v1" }, { "created": "Sun, 20 Feb 2005 17:56:12 GMT", "version": "v2" } ]
2007-05-23
[ [ "Csernai", "L. P.", "" ], [ "Magas", "V. K.", "" ], [ "Molnar", "E.", "" ], [ "Nyiri", "A.", "" ], [ "Tamosiunas", "K.", "" ] ]
Recently several works have appeared in the literature that addressed the problem of Freeze Out in energetic heavy ion reaction and aimed for a description based on the Boltzmann Transport Equation (BTE). In this paper we develop a dynamical Freeze-Out description, starting from the BTE, pointing out the basic limitations of the BTE approach, and the points where the BTE approach should be modified.
2008.06364
Carlo Oleari
Paolo Nason, Carlo Oleari, Marco Rocco, Marco Zaro
An interface between the POWHEG BOX and MadGraph5_aMC@NLO
20 pages, 13 figures
null
10.1140/epjc/s10052-020-08559-7
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper we present a framework for developing POWHEG BOX generators using MadGraph5_aMC@NLO for the computation of the matrix elements. Within this framework, all the flexibility of MadGraph5_aMC@NLO for the generation of matrix elements for Standard Model processes and for several of its extensions can be exploited, as well as all features of the POWHEG BOX framework, including the possibility of multijet merging without a merging scale (using the so called MiNLO approach). As a proof of concept, we develop a generator for the production of a spin-0 Higgs-like boson in association with up to two jets, with CP-violating couplings.
[ { "created": "Fri, 14 Aug 2020 13:31:25 GMT", "version": "v1" } ]
2020-12-02
[ [ "Nason", "Paolo", "" ], [ "Oleari", "Carlo", "" ], [ "Rocco", "Marco", "" ], [ "Zaro", "Marco", "" ] ]
In this paper we present a framework for developing POWHEG BOX generators using MadGraph5_aMC@NLO for the computation of the matrix elements. Within this framework, all the flexibility of MadGraph5_aMC@NLO for the generation of matrix elements for Standard Model processes and for several of its extensions can be exploited, as well as all features of the POWHEG BOX framework, including the possibility of multijet merging without a merging scale (using the so called MiNLO approach). As a proof of concept, we develop a generator for the production of a spin-0 Higgs-like boson in association with up to two jets, with CP-violating couplings.
1107.2670
Florian Staub
Renato M. Fonseca, Michal Malinsky, Werner Porod, Florian Staub
Running soft parameters in SUSY models with multiple U(1) gauge factors
18 pages, 10 figures; v2: matches published version; v3: corrected eqs. (21) and (35), changed text in sec. 3.B accordingly
Nuclear Physics, Section B 854 (2012), pp. 28-53
10.1016/j.nuclphysb.2011.08.017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalize the two-loop renormalization group equations for the parameters of the softly broken SUSY gauge theories given in the literature to the most general case when the gauge group contains more than a single abelian gauge factor. The complete method is illustrated at two-loop within a specific example and compared to some of the previously proposed partial treatments.
[ { "created": "Wed, 13 Jul 2011 20:34:36 GMT", "version": "v1" }, { "created": "Mon, 26 Sep 2011 15:33:37 GMT", "version": "v2" }, { "created": "Wed, 19 Sep 2012 17:28:41 GMT", "version": "v3" } ]
2012-09-20
[ [ "Fonseca", "Renato M.", "" ], [ "Malinsky", "Michal", "" ], [ "Porod", "Werner", "" ], [ "Staub", "Florian", "" ] ]
We generalize the two-loop renormalization group equations for the parameters of the softly broken SUSY gauge theories given in the literature to the most general case when the gauge group contains more than a single abelian gauge factor. The complete method is illustrated at two-loop within a specific example and compared to some of the previously proposed partial treatments.
1106.3189
Guido Altarelli
G. Altarelli
The Early Days of QCD (as seen from Rome)
8 pages, 2 figures. Talk in honour of Mario Greco presented at the Rencontres de la Vallee d'Aoste 2011, La Thuile, Italy
null
10.1393/ncc/i2012-11159-y
RM3-TH/11-03, CERN-PH-TH/2011-140
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In honour of Mario Greco I present my recollections on the QCD studies in Rome in the '70's and early 80's and on our very friendly group of people involved.
[ { "created": "Thu, 16 Jun 2011 10:10:19 GMT", "version": "v1" } ]
2022-03-02
[ [ "Altarelli", "G.", "" ] ]
In honour of Mario Greco I present my recollections on the QCD studies in Rome in the '70's and early 80's and on our very friendly group of people involved.
1301.3339
Elena G. Ferreiro
A. Capella and E. G. Ferreiro
Proton-proton multiplicity distributions at LHC and the Pomeron intercept
6 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the proton-proton multiplicity distributions at LHC energies in the framework of a multiple scattering model assuming a Poisson distribution for each inelastic collision. Multiple scattering is essential to broaden the multiplicity distribution. We obtain approximate KNO scaling for small pseudo-rapidity intervals ($|\eta | < 0.5$) and sizable KNO scaling violations for larger ones, in agreement with experiment.
[ { "created": "Tue, 15 Jan 2013 13:22:34 GMT", "version": "v1" } ]
2013-01-16
[ [ "Capella", "A.", "" ], [ "Ferreiro", "E. G.", "" ] ]
We compute the proton-proton multiplicity distributions at LHC energies in the framework of a multiple scattering model assuming a Poisson distribution for each inelastic collision. Multiple scattering is essential to broaden the multiplicity distribution. We obtain approximate KNO scaling for small pseudo-rapidity intervals ($|\eta | < 0.5$) and sizable KNO scaling violations for larger ones, in agreement with experiment.
2001.01726
Haowu Duan
Haowu Duan, Candost Akkaya, Alex Kovner, and Vladimir V. Skokov
Entanglement, partial set of measurements, and diagonality of the density matrix in the parton model
11 pages, 1 figure; version accepted to Phys. Rev. D
Phys. Rev. D 101, 036017 (2020)
10.1103/PhysRevD.101.036017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We define the "entropy of ignorance" which quantifies the entropy associated with ability to perform only a partial set of measurement on a quantum system. For a parton model the entropy of ignorance is equal to a Boltzmann entropy of a classical system of partons. We analyze a calculable model used for describing low x gluons in Color Glass Condensate approach, which has similarities with the parton model of QCD. In this model we calculate the entropy of ignorance in the particle number basis as well as the entanglement entropy of the observable degrees of freedom. We find that the two are similar at high momenta, but differ by a factor of order unity at low momenta. This holds for the Renyi as well as von Neumann entropies. We conclude that the entanglement does not seem to play an important role in the context of the parton model.
[ { "created": "Mon, 6 Jan 2020 19:00:02 GMT", "version": "v1" }, { "created": "Tue, 3 Mar 2020 19:19:26 GMT", "version": "v2" } ]
2020-03-05
[ [ "Duan", "Haowu", "" ], [ "Akkaya", "Candost", "" ], [ "Kovner", "Alex", "" ], [ "Skokov", "Vladimir V.", "" ] ]
We define the "entropy of ignorance" which quantifies the entropy associated with ability to perform only a partial set of measurement on a quantum system. For a parton model the entropy of ignorance is equal to a Boltzmann entropy of a classical system of partons. We analyze a calculable model used for describing low x gluons in Color Glass Condensate approach, which has similarities with the parton model of QCD. In this model we calculate the entropy of ignorance in the particle number basis as well as the entanglement entropy of the observable degrees of freedom. We find that the two are similar at high momenta, but differ by a factor of order unity at low momenta. This holds for the Renyi as well as von Neumann entropies. We conclude that the entanglement does not seem to play an important role in the context of the parton model.
hep-ph/0008003
Alejandro Cabo Montes De Oca
Alejandro Cabo and Marcos Rigol
Constituent quark masses from a modified perturbative QCD
Revtex 4, 29 pages, 4 tables, 6 eps figures, extended version of a letter. Title changed, content and references added, two figures improved
Eur. Phys. J. C23, 289 (2002)
10.1007/s100520100879
null
hep-ph
null
A recently proposed modified perturbative expansion for QCD incorporating gluon condensation is employed to evaluate the quark and gluon self-energy corrections in the first approximations. The results predict mass values of 1/3 of the nucleon mass for the light quarks u, d, and s and a monotonously growing variation with the current mass. The only phenomenological input consists in that <G^2> is evaluated up to order g^2 as a function of the unique parameter C defining the modified propagator and then C is fixed to give a current estimate of <g^2 G^2>. The light quarks u and d result to be confined and the s, c, b and t ones show damped propagation modes, then suggesting a model for the large differences in stability between the nucleons and the higher resonances. The above properties of quark modes diverge from the fully confinement result following from the similar gluon propagator previously considered by Munczek and Nemirovski. On another hand, the condensate effects on the gluon self-energy furnish a tachionic mass shell as predicted by the Fukuda analysis of gluon condensation in QCD.
[ { "created": "Tue, 1 Aug 2000 09:33:27 GMT", "version": "v1" }, { "created": "Wed, 14 Feb 2001 18:03:55 GMT", "version": "v2" }, { "created": "Mon, 7 Jan 2002 10:51:09 GMT", "version": "v3" }, { "created": "Wed, 22 May 2002 07:58:31 GMT", "version": "v4" } ]
2009-10-31
[ [ "Cabo", "Alejandro", "" ], [ "Rigol", "Marcos", "" ] ]
A recently proposed modified perturbative expansion for QCD incorporating gluon condensation is employed to evaluate the quark and gluon self-energy corrections in the first approximations. The results predict mass values of 1/3 of the nucleon mass for the light quarks u, d, and s and a monotonously growing variation with the current mass. The only phenomenological input consists in that <G^2> is evaluated up to order g^2 as a function of the unique parameter C defining the modified propagator and then C is fixed to give a current estimate of <g^2 G^2>. The light quarks u and d result to be confined and the s, c, b and t ones show damped propagation modes, then suggesting a model for the large differences in stability between the nucleons and the higher resonances. The above properties of quark modes diverge from the fully confinement result following from the similar gluon propagator previously considered by Munczek and Nemirovski. On another hand, the condensate effects on the gluon self-energy furnish a tachionic mass shell as predicted by the Fukuda analysis of gluon condensation in QCD.
1610.08083
Sara Saa
M.B. Gavela, K. Kanshin, P.A.N. Machado, S. Saa
The linear-non-linear frontier for the Goldstone Higgs
23 pages, 1 figure and 3 tables
null
10.1140/epjc/s10052-016-4541-7
DFPD-2016/TH/17; FERMILAB-PUB-16-471-T; FTUAM-16-39; IFT-UAM/CSIC-16-107
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The minimal $SO(5)/SO(4)$ sigma model is used as a template for the ultraviolet completion of scenarios in which the Higgs particle is a low-energy remnant of some high-energy dynamics, enjoying a (pseudo) Nambu-Goldstone boson ancestry. Varying the $\sigma$ mass allows to sweep from the perturbative regime to the customary non-linear implementations. The low-energy benchmark effective non-linear Lagrangian for bosons and fermions is obtained, determining as well the operator coefficients including linear corrections. At first order in the latter, three effective bosonic operators emerge which are independent of the explicit soft breaking assumed. The Higgs couplings to vector bosons and fermions turn out to be quite universal: the linear corrections are proportional to the explicit symmetry breaking parameters. Furthermore, we define an effective Yukawa operator which allows a simple parametrization and comparison of different heavy fermion ultraviolet completions. In addition, one particular fermionic completion is explored in detail, obtaining the corresponding leading low-energy fermionic operators.
[ { "created": "Tue, 25 Oct 2016 20:28:19 GMT", "version": "v1" } ]
2017-02-01
[ [ "Gavela", "M. B.", "" ], [ "Kanshin", "K.", "" ], [ "Machado", "P. A. N.", "" ], [ "Saa", "S.", "" ] ]
The minimal $SO(5)/SO(4)$ sigma model is used as a template for the ultraviolet completion of scenarios in which the Higgs particle is a low-energy remnant of some high-energy dynamics, enjoying a (pseudo) Nambu-Goldstone boson ancestry. Varying the $\sigma$ mass allows to sweep from the perturbative regime to the customary non-linear implementations. The low-energy benchmark effective non-linear Lagrangian for bosons and fermions is obtained, determining as well the operator coefficients including linear corrections. At first order in the latter, three effective bosonic operators emerge which are independent of the explicit soft breaking assumed. The Higgs couplings to vector bosons and fermions turn out to be quite universal: the linear corrections are proportional to the explicit symmetry breaking parameters. Furthermore, we define an effective Yukawa operator which allows a simple parametrization and comparison of different heavy fermion ultraviolet completions. In addition, one particular fermionic completion is explored in detail, obtaining the corresponding leading low-energy fermionic operators.
1609.04688
Carlo Giunti Dr.
Carlo Giunti
Oscillations Beyond Three-Neutrino Mixing
8 pages; proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, UK
null
10.1088/1742-6596/888/1/012019
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The current status of the phenomenology of short-baseline neutrino oscillations induced by light sterile neutrinos in the framework of 3+1 mixing is reviewed.
[ { "created": "Thu, 15 Sep 2016 15:05:59 GMT", "version": "v1" }, { "created": "Mon, 3 Oct 2016 09:32:38 GMT", "version": "v2" } ]
2017-10-11
[ [ "Giunti", "Carlo", "" ] ]
The current status of the phenomenology of short-baseline neutrino oscillations induced by light sterile neutrinos in the framework of 3+1 mixing is reviewed.
hep-ph/0510060
A. V. Luchinsky
V. V. Braguta, A. K. Likhoded, A. V. Luchinsky
Inclusive decays \chi_{b0,2}->\psi D\bar D+X and the duality relation
8 pages, 3 figures; minor changes
Phys.Rev.D73:034021,2006; Phys.Atom.Nucl.70:901-907,2007; Yad.Fiz.70:934-940,2007
10.1103/PhysRevD.73.034021 10.1134/S1063778807050134
null
hep-ph
null
In this article we consider the three-particle decays $\chi_{b0,2}\to J/\psi c\bar c\to J/\psi D\bar D+X$. We present the analytical formulae for the differential widths of these decays, the numerical values of their integrated widths and check the duality relation that connects the decays $\chi_{b0,2}\to\psi c\bar c$ with the two-particle decays $\chi_{b0,2}\to J/\psi (c\bar c)$. We also study the possibility of observing the $\chi_{b0,2}\to J/\psi DD+X$ mode at Tevatron and LHC colliders.
[ { "created": "Wed, 5 Oct 2005 15:31:27 GMT", "version": "v1" }, { "created": "Sun, 25 Dec 2005 12:13:40 GMT", "version": "v2" } ]
2008-11-26
[ [ "Braguta", "V. V.", "" ], [ "Likhoded", "A. K.", "" ], [ "Luchinsky", "A. V.", "" ] ]
In this article we consider the three-particle decays $\chi_{b0,2}\to J/\psi c\bar c\to J/\psi D\bar D+X$. We present the analytical formulae for the differential widths of these decays, the numerical values of their integrated widths and check the duality relation that connects the decays $\chi_{b0,2}\to\psi c\bar c$ with the two-particle decays $\chi_{b0,2}\to J/\psi (c\bar c)$. We also study the possibility of observing the $\chi_{b0,2}\to J/\psi DD+X$ mode at Tevatron and LHC colliders.
hep-ph/0302064
Johan Bijnens
Olof Strandberg (Lund)
Determination of the Anomalous Chiral Coefficients of order $p^{6}$
45 pages, Master thesis with advisor Johan Bijnens
null
null
LU TP 03-02
hep-ph
null
Symmetries affected by the anomaly do not survive quantization and cannot be understood classically. They are of fundamental importance and offer an opportunity of expanding the theoretical framework. We examine the theory of the anomalous sector, starting from lowest order Chiral Perturbation Theory (ChPT), leading up to the construction of the recently developed Lagrangian of $\mathcal{O}(p^{6}) $ describing anomalous processes. This Lagrangian contains a set of chiral coefficients that must be determined phenomenologically. Using currently available experimental data, we fit as many of these coefficients as possible. The results of the ChPT treatment are then used to test the validity of the two main alternative models employed in the anomalous sector - Vector Meson Dominance (VMD) and the constituent Chiral Quark Model (CQM).
[ { "created": "Mon, 10 Feb 2003 12:59:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Strandberg", "Olof", "", "Lund" ] ]
Symmetries affected by the anomaly do not survive quantization and cannot be understood classically. They are of fundamental importance and offer an opportunity of expanding the theoretical framework. We examine the theory of the anomalous sector, starting from lowest order Chiral Perturbation Theory (ChPT), leading up to the construction of the recently developed Lagrangian of $\mathcal{O}(p^{6}) $ describing anomalous processes. This Lagrangian contains a set of chiral coefficients that must be determined phenomenologically. Using currently available experimental data, we fit as many of these coefficients as possible. The results of the ChPT treatment are then used to test the validity of the two main alternative models employed in the anomalous sector - Vector Meson Dominance (VMD) and the constituent Chiral Quark Model (CQM).
2303.08764
Anders Rehult
Robert Fleischer, Eleftheria Malami, Anders Rehult, K. Keri Vos
New Perspectives for Testing Electron-Muon Universality
18 pages, 6 figures
null
10.1007/JHEP06(2023)033
Nikhef-2023-002, SI-HEP-2023-05, P3H-23-014
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Intriguing results for tests of the universality of electrons and muons through measurements of rates of $B\to K \ell^+ \ell^-$ and similar decays have been in the spotlight for years. The LHCb collaboration has recently reported new results which are in agreement with Lepton Flavour Universality, while the individual decay rates are found below their Standard Model predictions. In view of this new situation, we explore how much space is left for a violation of electron-muon universality. Considering new sources of CP violation and taking the new LHCb measurements into account, we show that significant differences between the short-distance coefficients for electronic and muonic final states are actually allowed by the current data. These patterns can be revealed through CP asymmetries in neutral and charged $B\to K \ell^+ \ell^-$ decays. We obtain correlations between these observables and map them to the short-distance coefficients. This results in regions in New Physics parameter space with large differences between CP asymmetries of the decays with final-state electrons and muons, thereby leaving a lot of room for possible surprises in the future high-precision era.
[ { "created": "Wed, 15 Mar 2023 17:02:36 GMT", "version": "v1" } ]
2023-06-21
[ [ "Fleischer", "Robert", "" ], [ "Malami", "Eleftheria", "" ], [ "Rehult", "Anders", "" ], [ "Vos", "K. Keri", "" ] ]
Intriguing results for tests of the universality of electrons and muons through measurements of rates of $B\to K \ell^+ \ell^-$ and similar decays have been in the spotlight for years. The LHCb collaboration has recently reported new results which are in agreement with Lepton Flavour Universality, while the individual decay rates are found below their Standard Model predictions. In view of this new situation, we explore how much space is left for a violation of electron-muon universality. Considering new sources of CP violation and taking the new LHCb measurements into account, we show that significant differences between the short-distance coefficients for electronic and muonic final states are actually allowed by the current data. These patterns can be revealed through CP asymmetries in neutral and charged $B\to K \ell^+ \ell^-$ decays. We obtain correlations between these observables and map them to the short-distance coefficients. This results in regions in New Physics parameter space with large differences between CP asymmetries of the decays with final-state electrons and muons, thereby leaving a lot of room for possible surprises in the future high-precision era.
2005.08218
Jorge Segovia
J. Segovia, C. Albertus, D.R. Entem, F. Fern\'andez, E. Hern\'andez, M.A. P\'erez-Garc\'ia
Weak B Decays into Orbitally Excited Charmed Mesons
Contribution to the proceedings of the XIV International Conference on Hadron Spectroscopy (HADRON 2011); 13-17 June 2011, Munich, Germany
eConf C110613:622 (2011)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The BaBar Collaboration has recently reported branching fractions for semileptonic decays of the $B$ meson into final states with charged and neutral $D_{1}(2420)$ and $D_{2}^{\ast}(2460)$, two narrow orbitally excited charmed mesons. We evaluate these branching fractions within the framework of a constituent quark model in two steps, one which involves a semileptonic decay and the other one mediated by a strong process. Our results are in agreement with the experimental data.
[ { "created": "Sun, 17 May 2020 11:00:37 GMT", "version": "v1" } ]
2020-05-19
[ [ "Segovia", "J.", "" ], [ "Albertus", "C.", "" ], [ "Entem", "D. R.", "" ], [ "Fernández", "F.", "" ], [ "Hernández", "E.", "" ], [ "Pérez-García", "M. A.", "" ] ]
The BaBar Collaboration has recently reported branching fractions for semileptonic decays of the $B$ meson into final states with charged and neutral $D_{1}(2420)$ and $D_{2}^{\ast}(2460)$, two narrow orbitally excited charmed mesons. We evaluate these branching fractions within the framework of a constituent quark model in two steps, one which involves a semileptonic decay and the other one mediated by a strong process. Our results are in agreement with the experimental data.
hep-ph/0501112
Loiseau Benoit
B. Loiseau, S. Wycech
Antiproton-Proton Channels in J/psi Decays
6 pages, 5 figures. The antiproton-proton pair being in isospin one in the J/Psi decay into neutral pion-antiproton-proton, the antiproton-proton 1P1 and 3S1 waves have been replaced by the 31P1 and 33S1 ones and Figs. 1 and 2 have been replaced accordingly. Conclusions are unchanged. Most of the content of the paper is published in Phys. Rev. C72, 011001 (2005)
Phys.Rev.C72:011001,2005
10.1103/PhysRevC.72.011001
LPNHE 2005-01
hep-ph
null
The recent measurements by the BES Collaboration of J/psi decays into a photon and a proton-antiproton pair indicate a strong enhancement at the proton-antiproton threshold not observed in the decays into a neutral pion and a proton-antiproton pair. Is this enhancement due to a proton-antiproton quasi-bound state or a baryonium? A natural explanation follows from a traditional model of proton-antiproton interactions based on G-parity transformation. The observed proton-antiproton structure is due to a strong attraction in the 1S0 state, and possibly to a near-threshold quasi-bound state in the 11S0 wave.
[ { "created": "Thu, 13 Jan 2005 19:13:34 GMT", "version": "v1" }, { "created": "Fri, 16 Dec 2005 09:34:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Loiseau", "B.", "" ], [ "Wycech", "S.", "" ] ]
The recent measurements by the BES Collaboration of J/psi decays into a photon and a proton-antiproton pair indicate a strong enhancement at the proton-antiproton threshold not observed in the decays into a neutral pion and a proton-antiproton pair. Is this enhancement due to a proton-antiproton quasi-bound state or a baryonium? A natural explanation follows from a traditional model of proton-antiproton interactions based on G-parity transformation. The observed proton-antiproton structure is due to a strong attraction in the 1S0 state, and possibly to a near-threshold quasi-bound state in the 11S0 wave.
hep-ph/0512099
Matthias Steinhauser
D. Eiras, M. Steinhauser
Two-Loop ${\cal O}(\alpha\alpha_s)$ Corrections to the On-Shell Fermion Propagator in the Standard Model
34 pages
JHEP 0602:010,2006
10.1088/1126-6708/2006/02/010
SFB/CPP-05-78, TTP05-26
hep-ph
null
In this paper we consider mixed two-loop electroweak corrections to the top quark propagator in the Standard Model. In particular, we compute the on-shell renormalization constant for the mass and wave function, which constitute building blocks for many physical processes. The results are expressed in terms of master integrals. For the latter practical approximations are derived. In the case of the mass renormalization constant we find agreement with the results in the literature.
[ { "created": "Thu, 8 Dec 2005 12:05:38 GMT", "version": "v1" } ]
2011-01-13
[ [ "Eiras", "D.", "" ], [ "Steinhauser", "M.", "" ] ]
In this paper we consider mixed two-loop electroweak corrections to the top quark propagator in the Standard Model. In particular, we compute the on-shell renormalization constant for the mass and wave function, which constitute building blocks for many physical processes. The results are expressed in terms of master integrals. For the latter practical approximations are derived. In the case of the mass renormalization constant we find agreement with the results in the literature.
1406.7652
Christian Reuschle
Christian Reuschle, Stefan Weinzierl
Color decomposition of multi-quark one-loop QCD amplitudes
10 pages. Talk given at Loops and Legs 2014
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we discuss the color decomposition of tree-level and one-loop QCD amplitudes with arbitrary numbers of quarks and gluons. We present a method for the decomposition of partial amplitudes into primitive amplitudes, which is based on shuffle relations and is purely combinatorial. Closed formulae are derived, which do not require the inversion of a system of linear equations.
[ { "created": "Mon, 30 Jun 2014 10:13:00 GMT", "version": "v1" }, { "created": "Wed, 2 Jul 2014 16:04:48 GMT", "version": "v2" } ]
2014-07-03
[ [ "Reuschle", "Christian", "" ], [ "Weinzierl", "Stefan", "" ] ]
In this talk we discuss the color decomposition of tree-level and one-loop QCD amplitudes with arbitrary numbers of quarks and gluons. We present a method for the decomposition of partial amplitudes into primitive amplitudes, which is based on shuffle relations and is purely combinatorial. Closed formulae are derived, which do not require the inversion of a system of linear equations.
1510.08218
Renata Jora
Amir H. Fariborz, Renata Jora
Note on the standard model as an effective theory
8 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a criterion of consistency derived from the analogy between the partition function of a quantum field theory and that of a statistical system. Based on this we examine a new class of higher dimension operators that might act in the standard model.
[ { "created": "Wed, 28 Oct 2015 08:00:01 GMT", "version": "v1" } ]
2015-10-29
[ [ "Fariborz", "Amir H.", "" ], [ "Jora", "Renata", "" ] ]
We present a criterion of consistency derived from the analogy between the partition function of a quantum field theory and that of a statistical system. Based on this we examine a new class of higher dimension operators that might act in the standard model.
1503.06783
Mitsuru Kakizaki
Mitsuru Kakizaki, Eun-Kyung Park, Jae-hyeon Park and Akiteru Santa
Phenomenological constraints on light mixed sneutrino dark matter scenarios
14 pages, 1 figure
null
10.1016/j.physletb.2015.07.030
UT-HET-094, EPHOU-15-008, FTUV-15-8555, IFIC-15-15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In supersymmetric models with Dirac neutrinos, the lightest sneutrino can be an excellent thermal dark matter candidate when the soft sneutrino trilinear parameter is large. We focus on scenarios where the mass of the mixed sneutrino is of the order of GeV and sensitivity of dark matter direct detection is weak. We investigate phenomenological constraints on the model parameter space including the vacuum stability bound. We show that the allowed regions can be explored by measuring Higgs boson properties at future collider experiments.
[ { "created": "Mon, 23 Mar 2015 19:52:33 GMT", "version": "v1" }, { "created": "Fri, 11 Mar 2022 07:30:59 GMT", "version": "v2" } ]
2022-03-14
[ [ "Kakizaki", "Mitsuru", "" ], [ "Park", "Eun-Kyung", "" ], [ "Park", "Jae-hyeon", "" ], [ "Santa", "Akiteru", "" ] ]
In supersymmetric models with Dirac neutrinos, the lightest sneutrino can be an excellent thermal dark matter candidate when the soft sneutrino trilinear parameter is large. We focus on scenarios where the mass of the mixed sneutrino is of the order of GeV and sensitivity of dark matter direct detection is weak. We investigate phenomenological constraints on the model parameter space including the vacuum stability bound. We show that the allowed regions can be explored by measuring Higgs boson properties at future collider experiments.
hep-ph/9511209
ChengXing Zhai
Lowell Brown and Chengxing Zhai
Atomic effects in tritium beta decay
81 pages, 15 Postscript figures, uses a non-standard style file "table.sty" which is appended at the end of the latex file
Annals Phys. 249 (1996) 298-361
10.1006/aphy.1996.0072
UW/PT-95-16, PURD-TH-95-11
hep-ph nucl-th
null
The electron neutrino mass has been measured in several tritium beta decay experiments. These experiments are sensitive to a small neutrino mass because the energy release of the decay is small. But the very smallness of the energy release implies that the Coulomb interactions of the slowly moving emitted beta electron are relatively large. Using field theoretic techniques, we derive a systematic and controlled expansion which accounts for the Coulomb effects, including the mutual interaction of the beta ray electron and the electron in the final $^3{\rm He}^+$ ion. In our formulation, an effective potential which describes the long range Coulomb force experienced by the beta ray is introduced to ensure that our expansion is free of infrared divergences. Both the exclusive differential decay rate to a specific final $^3{\rm He}^+$ state and the inclusive differential decay rate are calculated to order $\eta^2$, where $\eta$ is the usual Coulomb parameter. We analyze the order $\eta^2$ correction to the beta ray spectrum and estimate how it may affect the neutrino mass squared parameter and the endpoint energy when this corrected spectrum is used to compare with the experiments. We find that the effect is small.
[ { "created": "Thu, 2 Nov 1995 06:37:51 GMT", "version": "v1" } ]
2009-10-28
[ [ "Brown", "Lowell", "" ], [ "Zhai", "Chengxing", "" ] ]
The electron neutrino mass has been measured in several tritium beta decay experiments. These experiments are sensitive to a small neutrino mass because the energy release of the decay is small. But the very smallness of the energy release implies that the Coulomb interactions of the slowly moving emitted beta electron are relatively large. Using field theoretic techniques, we derive a systematic and controlled expansion which accounts for the Coulomb effects, including the mutual interaction of the beta ray electron and the electron in the final $^3{\rm He}^+$ ion. In our formulation, an effective potential which describes the long range Coulomb force experienced by the beta ray is introduced to ensure that our expansion is free of infrared divergences. Both the exclusive differential decay rate to a specific final $^3{\rm He}^+$ state and the inclusive differential decay rate are calculated to order $\eta^2$, where $\eta$ is the usual Coulomb parameter. We analyze the order $\eta^2$ correction to the beta ray spectrum and estimate how it may affect the neutrino mass squared parameter and the endpoint energy when this corrected spectrum is used to compare with the experiments. We find that the effect is small.
hep-ph/9809417
Vittorio Lubicz
Vittorio Lubicz
Light quark masses and CKM matrix elements from lattice QCD
5 pages, 4 figures, uses espcrc2.sty (included). Based on invited talk given at the QCD 98 Euroconference, Montpellier, France, 2-8 July 1998
Nucl.Phys.Proc.Suppl. 74 (1999) 291-295
10.1016/S0920-5632(99)00180-2
null
hep-ph hep-lat
null
I give a brief overview of recent results from lattice QCD calculations which are relevant for the phenomenology of the Standard Model. I discuss, in particular, the lattice determination of light quark masses and the calculation of those hadronic quantities, such as semileptonic form factors, decay constants and B-parameters, which are of particular interest for the analysis of the CKM mixing matrix and the origin of CP violation.
[ { "created": "Wed, 16 Sep 1998 16:23:51 GMT", "version": "v1" } ]
2009-10-31
[ [ "Lubicz", "Vittorio", "" ] ]
I give a brief overview of recent results from lattice QCD calculations which are relevant for the phenomenology of the Standard Model. I discuss, in particular, the lattice determination of light quark masses and the calculation of those hadronic quantities, such as semileptonic form factors, decay constants and B-parameters, which are of particular interest for the analysis of the CKM mixing matrix and the origin of CP violation.
hep-ph/9802211
Frank Klingl
F. Klingl and W. Weise
Vector mesons in medium
13 pages in Latex, talk given at the XXXVI International Winter Meeting on Nuclear Physics
null
null
null
hep-ph nucl-th
null
Based on an effective Lagrangian which combines chiral SU(3) dynamics with vector meson dominance, we have developed a model for the forward vector meson-nucleon scattering amplitudes. We use this as an input to calculate the low energy part of the current-current correlation function in nuclear matter. For the isovector channel we find a significant enhancement of the in-medium spectral density below the $\rho$ resonance while the $\rho$ meson mass itself changes only slightly. The situation is different in the isoscalar channel, where the mass and peak position of the $\omega$ meson move downward while its width increases moderately. For the $\phi$ meson we find almost no mass shift, but the width of the peak increases significantly. We use these spectra as ``left hand side'' of in medium QCD sum rules and observe a remarkable degree of consistency with the operator product expansion ``right hand''side in all three channels. We point out, however, that these results cannot simply be interpreted, as commonly done, in terms of a universal rescaling of vector meson masses in matter. We also compare the resulting thermal dilepton rates of our model with CERES data. We find satisfactory agreement but we point out that the dilepton rates from completely uncorrelated quark-antiquark pairs also fit the data quite well. Considering the strongly attractive potential for the $\omega$ together with its comparably small width, we discuss the possible formation of bound $\omega$ states in nuclei. Using a Green's function approach we investigate the possibility of detecting these bound states in the $A(d, ^3He) $ pick-up reaction.
[ { "created": "Mon, 2 Feb 1998 17:07:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Klingl", "F.", "" ], [ "Weise", "W.", "" ] ]
Based on an effective Lagrangian which combines chiral SU(3) dynamics with vector meson dominance, we have developed a model for the forward vector meson-nucleon scattering amplitudes. We use this as an input to calculate the low energy part of the current-current correlation function in nuclear matter. For the isovector channel we find a significant enhancement of the in-medium spectral density below the $\rho$ resonance while the $\rho$ meson mass itself changes only slightly. The situation is different in the isoscalar channel, where the mass and peak position of the $\omega$ meson move downward while its width increases moderately. For the $\phi$ meson we find almost no mass shift, but the width of the peak increases significantly. We use these spectra as ``left hand side'' of in medium QCD sum rules and observe a remarkable degree of consistency with the operator product expansion ``right hand''side in all three channels. We point out, however, that these results cannot simply be interpreted, as commonly done, in terms of a universal rescaling of vector meson masses in matter. We also compare the resulting thermal dilepton rates of our model with CERES data. We find satisfactory agreement but we point out that the dilepton rates from completely uncorrelated quark-antiquark pairs also fit the data quite well. Considering the strongly attractive potential for the $\omega$ together with its comparably small width, we discuss the possible formation of bound $\omega$ states in nuclei. Using a Green's function approach we investigate the possibility of detecting these bound states in the $A(d, ^3He) $ pick-up reaction.
0910.0203
Joao Pulido
Joao Pulido, C R Das, Marco Picariello
Remaining inconsistencies with solar neutrinos: can spin flavour precession provide a clue?
3 pages, 2 figures, contribution to TAUP 2009 (Rome)
J.Phys.Conf.Ser.203:012086,2010
10.1088/1742-6596/203/1/012086
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A few inconsistencies remain after it has been ascertained that LMA is the dominant solution to the solar neutrino problem: why is the SuperKamiokande spectrum flat and why is the Chlorine rate prediction over two standard deviations above the data. There also remains the ananswered and important question of whether the active neutrino flux is constant or time varying. We propose a scenario involving spin flavour precession to sterile neutrinos with three active flavours that predicts a flat SuperK spectrum and a Chlorine rate prediction more consistent with data. We also argue that running the Borexino experiment during the next few years may provide a very important clue as to the possible variability of the solar neutrino flux.
[ { "created": "Thu, 1 Oct 2009 15:33:27 GMT", "version": "v1" } ]
2010-02-11
[ [ "Pulido", "Joao", "" ], [ "Das", "C R", "" ], [ "Picariello", "Marco", "" ] ]
A few inconsistencies remain after it has been ascertained that LMA is the dominant solution to the solar neutrino problem: why is the SuperKamiokande spectrum flat and why is the Chlorine rate prediction over two standard deviations above the data. There also remains the ananswered and important question of whether the active neutrino flux is constant or time varying. We propose a scenario involving spin flavour precession to sterile neutrinos with three active flavours that predicts a flat SuperK spectrum and a Chlorine rate prediction more consistent with data. We also argue that running the Borexino experiment during the next few years may provide a very important clue as to the possible variability of the solar neutrino flux.
2111.13099
Katsuya Hashino
Katsuya Hashino, Shinya Kanemura and Tomo Takahashi
Primordial black holes as a probe of strongly first-order electroweak phase transition
14 pages, 2 figures. Version accepted by Physics Letters B
null
10.1016/j.physletb.2022.137261
OU-HET-1123
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Primordial black holes can be produced by density fluctuations generated from delayed vacuum decays of first-order phase transition. The primordial black holes generated at the electroweak phase transition have masses of about $10^{-5}$ solar mass. Such primordial black holes in the mass range can be tested by current and future microlensing observations, such as Subaru HSC, OGLE, PRIME and Roman telescope. Therefore, we may be able to explore new physics models with strongly first-order electroweak phase transition via primordial black holes. We examine this possibility by using models with first-order electroweak phase transition in the standard model effective field theory with dimension 6 and 8 operators. We find that depending on parameters of the phase transition a sufficient number of primordial black holes can be produced to be observed by above mentioned experiments. Our results would suggest that primordial black holes can be used as a new probe of models with strongly first-order electroweak phase transition, which has complementarity with measurements of the triple Higgs boson coupling at future collider experiments and observations of gravitational waves at future space-based interferometers.
[ { "created": "Thu, 25 Nov 2021 14:27:21 GMT", "version": "v1" }, { "created": "Wed, 22 Jun 2022 07:03:03 GMT", "version": "v2" } ]
2022-07-27
[ [ "Hashino", "Katsuya", "" ], [ "Kanemura", "Shinya", "" ], [ "Takahashi", "Tomo", "" ] ]
Primordial black holes can be produced by density fluctuations generated from delayed vacuum decays of first-order phase transition. The primordial black holes generated at the electroweak phase transition have masses of about $10^{-5}$ solar mass. Such primordial black holes in the mass range can be tested by current and future microlensing observations, such as Subaru HSC, OGLE, PRIME and Roman telescope. Therefore, we may be able to explore new physics models with strongly first-order electroweak phase transition via primordial black holes. We examine this possibility by using models with first-order electroweak phase transition in the standard model effective field theory with dimension 6 and 8 operators. We find that depending on parameters of the phase transition a sufficient number of primordial black holes can be produced to be observed by above mentioned experiments. Our results would suggest that primordial black holes can be used as a new probe of models with strongly first-order electroweak phase transition, which has complementarity with measurements of the triple Higgs boson coupling at future collider experiments and observations of gravitational waves at future space-based interferometers.
2309.09581
Tanjona Radonirina Rabemananjara
Juan M. Cruz-Martinez, Max Fieg, Tommaso Giani, Peter Krack, Toni M\"akel\"a, Tanjona Rabemananjara, Juan Rojo
The LHC as a Neutrino-Ion Collider
42 pages, 22 figures. Added detailed studies on fluxes uncertainties
null
null
Nikhef-2023-009, CERN-TH-2023-165
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Proton-proton collisions at the LHC generate a high-intensity collimated beam of neutrinos in the forward (beam) direction, characterised by energies of up to several TeV. The recent observation of LHC neutrinos by FASER$\nu$ and SND@LHC signals that this hitherto ignored particle beam is now available for scientific inquiry. Here we quantify the impact that neutrino deep-inelastic scattering (DIS) measurements at the LHC would have on the parton distributions (PDFs) of protons and heavy nuclei. We generate projections for DIS structure functions for FASER$\nu$ and SND@LHC at Run III, as well as for the FASER$\nu$2, AdvSND, and FLArE experiments to be hosted at the proposed Forward Physics Facility (FPF) operating concurrently with the High-Luminosity LHC (HL-LHC). We determine that up to one million electron- and muon-neutrino DIS interactions within detector acceptance can be expected by the end of the HL-LHC, covering a kinematic region in $x$ and $Q^2$ overlapping with that of the Electron-Ion Collider. Including these DIS projections into global (n)PDF analyses, specifically PDF4LHC21, NNPDF4.0, and EPPS21, reveals a significant reduction of PDF uncertainties, in particular for strangeness and the up and down valence PDFs. We show that LHC neutrino data enables improved theoretical predictions for core processes at the HL-LHC, such as Higgs and weak gauge boson production. Our analysis demonstrates that exploiting the LHC neutrino beam effectively provides CERN with a "Neutrino-Ion Collider" without requiring modifications in its accelerator infrastructure.
[ { "created": "Mon, 18 Sep 2023 08:43:13 GMT", "version": "v1" }, { "created": "Mon, 1 Apr 2024 17:45:56 GMT", "version": "v2" } ]
2024-04-02
[ [ "Cruz-Martinez", "Juan M.", "" ], [ "Fieg", "Max", "" ], [ "Giani", "Tommaso", "" ], [ "Krack", "Peter", "" ], [ "Mäkelä", "Toni", "" ], [ "Rabemananjara", "Tanjona", "" ], [ "Rojo", "Juan", "" ] ]
Proton-proton collisions at the LHC generate a high-intensity collimated beam of neutrinos in the forward (beam) direction, characterised by energies of up to several TeV. The recent observation of LHC neutrinos by FASER$\nu$ and SND@LHC signals that this hitherto ignored particle beam is now available for scientific inquiry. Here we quantify the impact that neutrino deep-inelastic scattering (DIS) measurements at the LHC would have on the parton distributions (PDFs) of protons and heavy nuclei. We generate projections for DIS structure functions for FASER$\nu$ and SND@LHC at Run III, as well as for the FASER$\nu$2, AdvSND, and FLArE experiments to be hosted at the proposed Forward Physics Facility (FPF) operating concurrently with the High-Luminosity LHC (HL-LHC). We determine that up to one million electron- and muon-neutrino DIS interactions within detector acceptance can be expected by the end of the HL-LHC, covering a kinematic region in $x$ and $Q^2$ overlapping with that of the Electron-Ion Collider. Including these DIS projections into global (n)PDF analyses, specifically PDF4LHC21, NNPDF4.0, and EPPS21, reveals a significant reduction of PDF uncertainties, in particular for strangeness and the up and down valence PDFs. We show that LHC neutrino data enables improved theoretical predictions for core processes at the HL-LHC, such as Higgs and weak gauge boson production. Our analysis demonstrates that exploiting the LHC neutrino beam effectively provides CERN with a "Neutrino-Ion Collider" without requiring modifications in its accelerator infrastructure.
2105.03063
Muyang Chen
Muyang Chen
Scalar Mesons and Axial-vector Mesons Via Dyson-Schwinger Equation and Bethe-Salpeter Equation Approach
5 pages, 1 figure
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
In this work, I studied the spectrum of scalar mesons and axial-vector mesons via Dyson-Schwinger equation and Bethe-Salpeter equation approach in the rainbow-ladder approximation. An interaction model with a repulsive term added to the one used for the pseudoscalar and vector mesons is proposed. My results are consistent with the experiment data and other model results, which shows that this interaction model is effective for all the heavy, heavy-light, and light scalar and axial-vector mesons.
[ { "created": "Fri, 7 May 2021 04:25:20 GMT", "version": "v1" }, { "created": "Sat, 17 Jul 2021 23:21:39 GMT", "version": "v2" } ]
2021-07-20
[ [ "Chen", "Muyang", "" ] ]
In this work, I studied the spectrum of scalar mesons and axial-vector mesons via Dyson-Schwinger equation and Bethe-Salpeter equation approach in the rainbow-ladder approximation. An interaction model with a repulsive term added to the one used for the pseudoscalar and vector mesons is proposed. My results are consistent with the experiment data and other model results, which shows that this interaction model is effective for all the heavy, heavy-light, and light scalar and axial-vector mesons.
1502.03959
Motoi Endo
Motoi Endo, Takeo Moroi, Mihoko M. Nojiri
Footprints of Supersymmetry on Higgs Decay
24 pages, 8 figures, version accepted in JHEP
null
10.1007/JHEP04(2015)176
UT-15-02, IPMU-15-0018, KEK-TH-1795
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by future collider proposals that aim to measure the Higgs properties precisely, we study the partial decay widths of the lightest Higgs boson in the minimal supersymmetric standard model with an emphasis on the parameter region where all superparticles and heavy Higgs bosons are not accessible at the LHC. Taking account of phenomenological constraints such as the Higgs mass, flavor constraints, vacuum stability, and perturbativity of coupling constants up to the grand unification scale, we discuss how large the deviations of the partial decay widths from the standard model predictions can be. These constraints exclude large fraction of the parameter region where the Higgs widths show significant deviation from the standard model predictions. Nevertheless, even if superparticles and the heavy Higgses are out of the reach of 14TeV LHC, the deviation may be large enough to be observed at future $e^+e^-$ collider experiments.
[ { "created": "Fri, 13 Feb 2015 12:19:35 GMT", "version": "v1" }, { "created": "Thu, 30 Apr 2015 02:09:23 GMT", "version": "v2" } ]
2015-06-11
[ [ "Endo", "Motoi", "" ], [ "Moroi", "Takeo", "" ], [ "Nojiri", "Mihoko M.", "" ] ]
Motivated by future collider proposals that aim to measure the Higgs properties precisely, we study the partial decay widths of the lightest Higgs boson in the minimal supersymmetric standard model with an emphasis on the parameter region where all superparticles and heavy Higgs bosons are not accessible at the LHC. Taking account of phenomenological constraints such as the Higgs mass, flavor constraints, vacuum stability, and perturbativity of coupling constants up to the grand unification scale, we discuss how large the deviations of the partial decay widths from the standard model predictions can be. These constraints exclude large fraction of the parameter region where the Higgs widths show significant deviation from the standard model predictions. Nevertheless, even if superparticles and the heavy Higgses are out of the reach of 14TeV LHC, the deviation may be large enough to be observed at future $e^+e^-$ collider experiments.
1611.07980
Emanuele Roberto Nocera
Emanuele R. Nocera and Elena Santopinto
Can sea quark asymmetry shed light on the orbital angular momentum of the proton?
7 pages, 3 figures, 3 tables
null
null
OUTP-16-25P
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A striking prediction of several extensions of the constituent quark model, including the unquenched quark model, the pion cloud model and the chiral quark model, is a proportionality relationship between the quark sea asymmetry and the orbital angular momentum of the proton. We investigate to which extent a relationship of this kind is corroborated by the experiment, through a systematic comparison between expectations based on models and predictions obtained from a global analysis of hard-scattering data in perturbative Quantum Chromodynamics. We find that the data allows the angular momentum of the proton to be proportional to its sea asymmetry, though with a rather large range of the optimal values of the proportionality coefficient. Typical values do not enable us to discriminate among expectations based on different models. In order to make our comparison conclusive, the extrapolation uncertainties on the proportionality coefficient should be reduced, hopefully by means of accurate measurements in the region of small proton momentum fractions, where the data is currently lacking. Nevertheless, the unquenched quark model predicts that quarks account for a proton spin fraction much larger than that accepted by the conventional wisdom. We explicitly demonstrate that such a discrepancy can be reabsorbed in the unknown extrapolation region, without affecting the description of current data, by imposing the unquenched quark model expectation as a boundary condition in the analysis of the data itself. We delineate how the experimental programs at current and future facilities may shed light on the region of small momentum fractions.
[ { "created": "Wed, 23 Nov 2016 21:00:02 GMT", "version": "v1" } ]
2016-11-28
[ [ "Nocera", "Emanuele R.", "" ], [ "Santopinto", "Elena", "" ] ]
A striking prediction of several extensions of the constituent quark model, including the unquenched quark model, the pion cloud model and the chiral quark model, is a proportionality relationship between the quark sea asymmetry and the orbital angular momentum of the proton. We investigate to which extent a relationship of this kind is corroborated by the experiment, through a systematic comparison between expectations based on models and predictions obtained from a global analysis of hard-scattering data in perturbative Quantum Chromodynamics. We find that the data allows the angular momentum of the proton to be proportional to its sea asymmetry, though with a rather large range of the optimal values of the proportionality coefficient. Typical values do not enable us to discriminate among expectations based on different models. In order to make our comparison conclusive, the extrapolation uncertainties on the proportionality coefficient should be reduced, hopefully by means of accurate measurements in the region of small proton momentum fractions, where the data is currently lacking. Nevertheless, the unquenched quark model predicts that quarks account for a proton spin fraction much larger than that accepted by the conventional wisdom. We explicitly demonstrate that such a discrepancy can be reabsorbed in the unknown extrapolation region, without affecting the description of current data, by imposing the unquenched quark model expectation as a boundary condition in the analysis of the data itself. We delineate how the experimental programs at current and future facilities may shed light on the region of small momentum fractions.
1905.06965
Abhishek Mohapatra
Thomas Mehen and Abhishek Mohapatra
Perturbative Corrections to Heavy Quark-Diquark Symmetry Predictions for Doubly Heavy Baryon Hyperfine Splittings
15 pages, 6 figures, Added Section III and updated references and author name. Journal version
Phys. Rev. D 100, 076014 (2019)
10.1103/PhysRevD.100.076014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Doubly heavy baryons $\left(QQq\right)$ and singly heavy antimesons $\left(\bar{Q}q\right)$ are related by the heavy quark-diquark (HQDQ) symmetry because in the $m_Q \to \infty$ limit, the light degrees of freedom in both the hadrons are expected to be in identical configurations. Hyperfine splittings of the ground states in both systems are nonvanishing at $O(1/m_Q)$ in the heavy quark mass expansion and HQDQ symmetry relates the hyperfine splittings in the two sectors. In this paper, working within the framework of Non-Relativistic QCD (NRQCD), we point out the existence of an operator that couples four heavy quark fields to the chromomagnetic field with a coefficient that is enhanced by a factor from Coulomb exchange. This operator gives a correction to doubly heavy baryon hyperfine splittings that scales as $1/m_Q^2 \times \alpha_S/r$, where $r$ is the separation between the heavy quarks in the diquark. This correction can be calculated analytically in the extreme heavy quark limit in which the potential between the quarks in the diquark is Coulombic. In this limit, the correction is $O(\alpha_s^2/m_Q)$ and comes with a small coefficient. For values of $\alpha_s$ relevant to doubly charm and doubly bottom systems, the correction to the hyperfine splittings in doubly heavy baryons is only a few percent or smaller. We also argue that nonperturbative corrections to the prediction for the hyperfine splittings are suppressed by $\Lambda^2_{\rm QCD}/m_Q^2$ rather than $\Lambda_{\rm QCD}/m_Q$. Corrections should be $\approx 10\%$ in the charm sector and smaller in heavier systems.
[ { "created": "Thu, 16 May 2019 18:00:13 GMT", "version": "v1" }, { "created": "Wed, 29 May 2019 21:34:50 GMT", "version": "v2" }, { "created": "Mon, 21 Oct 2019 15:48:14 GMT", "version": "v3" } ]
2019-10-22
[ [ "Mehen", "Thomas", "" ], [ "Mohapatra", "Abhishek", "" ] ]
Doubly heavy baryons $\left(QQq\right)$ and singly heavy antimesons $\left(\bar{Q}q\right)$ are related by the heavy quark-diquark (HQDQ) symmetry because in the $m_Q \to \infty$ limit, the light degrees of freedom in both the hadrons are expected to be in identical configurations. Hyperfine splittings of the ground states in both systems are nonvanishing at $O(1/m_Q)$ in the heavy quark mass expansion and HQDQ symmetry relates the hyperfine splittings in the two sectors. In this paper, working within the framework of Non-Relativistic QCD (NRQCD), we point out the existence of an operator that couples four heavy quark fields to the chromomagnetic field with a coefficient that is enhanced by a factor from Coulomb exchange. This operator gives a correction to doubly heavy baryon hyperfine splittings that scales as $1/m_Q^2 \times \alpha_S/r$, where $r$ is the separation between the heavy quarks in the diquark. This correction can be calculated analytically in the extreme heavy quark limit in which the potential between the quarks in the diquark is Coulombic. In this limit, the correction is $O(\alpha_s^2/m_Q)$ and comes with a small coefficient. For values of $\alpha_s$ relevant to doubly charm and doubly bottom systems, the correction to the hyperfine splittings in doubly heavy baryons is only a few percent or smaller. We also argue that nonperturbative corrections to the prediction for the hyperfine splittings are suppressed by $\Lambda^2_{\rm QCD}/m_Q^2$ rather than $\Lambda_{\rm QCD}/m_Q$. Corrections should be $\approx 10\%$ in the charm sector and smaller in heavier systems.
1709.05082
Yueling Yang
Yueling Yang, Junfeng Sun, Jinshu Huang, Haiyan Li, Gongru Lu, Qin Chang
${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}D$ decays with perturbative QCD approach
18 pages, 3 figures, revtex
Int J Mod Phys A 31, 1650146 (2016)
10.1142/S0217751X16501463
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}D$ weak decays ($n$ $=$ $1$, $2$, $3$) are investigated with perturbative QCD approach. It is found that the CKM-favored ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}D_{s}$ decays have branching ratio of ${\cal O}(10^{-10})$, which might be potentially accessible to the future LHC and SuperKEKB experiments.
[ { "created": "Fri, 15 Sep 2017 07:25:56 GMT", "version": "v1" } ]
2017-09-19
[ [ "Yang", "Yueling", "" ], [ "Sun", "Junfeng", "" ], [ "Huang", "Jinshu", "" ], [ "Li", "Haiyan", "" ], [ "Lu", "Gongru", "" ], [ "Chang", "Qin", "" ] ]
The ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}D$ weak decays ($n$ $=$ $1$, $2$, $3$) are investigated with perturbative QCD approach. It is found that the CKM-favored ${\Upsilon}(nS)$ ${\to}$ $B_{c}^{\ast}D_{s}$ decays have branching ratio of ${\cal O}(10^{-10})$, which might be potentially accessible to the future LHC and SuperKEKB experiments.
1306.1631
Prashant Srivastava Kumar
P. K. Srivastava, S. K. Tiwari, C. P. Singh
Upsilon suppression at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider in a modified color screening scenario
7 pages, 7 figures, Revised version accepted for publication in Physical Review C. arXiv admin note: substantial text overlap with arXiv:1208.4796
Phys. Rev. C 88, 044902 (2013)
10.1103/PhysRevC.88.044902
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The suppression of heavy quarkonia e.g. $J/\psi$, $\Upsilon$ etc. is considered as a suitable probe to identify the nature of the matter created in heavy ion collisions. Recently we have presented a modified colour screening model for $J/\psi$ suppression in the quark gluon plasma (QGP) using quasiparticle model as the equation of state. In this paper, we extend our model to calculate the anomalous suppression of various states of $\Upsilon$ arising due to QGP medium alone. We obtain the suppression patterns of different bottomonia states with respect to centrality at various available collision energies and compare them with the available experimental data.
[ { "created": "Fri, 7 Jun 2013 06:47:49 GMT", "version": "v1" }, { "created": "Thu, 19 Sep 2013 05:04:27 GMT", "version": "v2" } ]
2013-10-04
[ [ "Srivastava", "P. K.", "" ], [ "Tiwari", "S. K.", "" ], [ "Singh", "C. P.", "" ] ]
The suppression of heavy quarkonia e.g. $J/\psi$, $\Upsilon$ etc. is considered as a suitable probe to identify the nature of the matter created in heavy ion collisions. Recently we have presented a modified colour screening model for $J/\psi$ suppression in the quark gluon plasma (QGP) using quasiparticle model as the equation of state. In this paper, we extend our model to calculate the anomalous suppression of various states of $\Upsilon$ arising due to QGP medium alone. We obtain the suppression patterns of different bottomonia states with respect to centrality at various available collision energies and compare them with the available experimental data.
1610.04096
Marcela Gonz\'alez
Carolina Arbel\'aez, Marcela Gonz\'alez, Martin Hirsch, Sergey Kovalenko
QCD Corrections and Long-Range Mechanisms of neutrinoless double beta decay
Updated after erratum
Phys. Rev. D 94, 096014 (2016)
10.1103/PhysRevD.94.096014
IFIC/16-70
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently it has been demonstrated that QCD corrections are numerically important for short-range mechanisms (SRM) of neutrinoless double beta decay ($0\nu\beta\beta$) mediated by heavy particle exchange. This is due to the effect of color mismatch for certain effective operators, which leads to mixing between different operators with vastly different nuclear matrix elements (NMEs). In this note we analyze the QCD corrections for long-range mechanisms (LRM), due to diagrams with light-neutrino exchange between a Standard Model (V-A)$\times$(V-A) and a beyond the SM lepton number violating vertex. We argue that in contrast to the SRM in the LRM case, there is no operator mixing from color-mismatched operators. This is due to a combined effect of the nuclear short-range correlations and color invariance. As a result, the QCD corrections to the LRM amount to an effect no more than 60%, depending on the operator in question. Although less crucial, taken into account QCD running makes theoretical predictions for $0\nu\beta\beta$-decay more robust also for LRM diagrams. We derive the current experimental constraints on the Wilson coefficients for all LRM effective operators.
[ { "created": "Thu, 13 Oct 2016 14:23:59 GMT", "version": "v1" }, { "created": "Wed, 23 Nov 2016 14:52:34 GMT", "version": "v2" }, { "created": "Fri, 20 Jul 2018 18:14:56 GMT", "version": "v3" } ]
2018-07-24
[ [ "Arbeláez", "Carolina", "" ], [ "González", "Marcela", "" ], [ "Hirsch", "Martin", "" ], [ "Kovalenko", "Sergey", "" ] ]
Recently it has been demonstrated that QCD corrections are numerically important for short-range mechanisms (SRM) of neutrinoless double beta decay ($0\nu\beta\beta$) mediated by heavy particle exchange. This is due to the effect of color mismatch for certain effective operators, which leads to mixing between different operators with vastly different nuclear matrix elements (NMEs). In this note we analyze the QCD corrections for long-range mechanisms (LRM), due to diagrams with light-neutrino exchange between a Standard Model (V-A)$\times$(V-A) and a beyond the SM lepton number violating vertex. We argue that in contrast to the SRM in the LRM case, there is no operator mixing from color-mismatched operators. This is due to a combined effect of the nuclear short-range correlations and color invariance. As a result, the QCD corrections to the LRM amount to an effect no more than 60%, depending on the operator in question. Although less crucial, taken into account QCD running makes theoretical predictions for $0\nu\beta\beta$-decay more robust also for LRM diagrams. We derive the current experimental constraints on the Wilson coefficients for all LRM effective operators.
hep-ph/9302261
null
N. Kaiser, R. A. Malaney, G.D. Starkman
Neutrino-Lasing in The Early Universe
7 pages, 3 figures included as uuencoded file, CITA/93/7
Phys.Rev.Lett. 71 (1993) 1128-1131
10.1103/PhysRevLett.71.1128
null
hep-ph astro-ph
null
Recently, Madsen has argued that relativistic decays of massive neutrinos into lighter fermions and bosons may lead, via thermalization, to the formation of a Bose condensate. If correct, this could generate mixed hot and cold dark matter, with important consequences for structure formation. From a detailed study of such decays, we arrive at substantially different conclusions; for a wide range of masses and decay times, we find that stimulated emission of bosons dominates the decay. This phenomenon can best be described as a neutrino laser, pumped by the QCD phase transition. We discuss the implications for structure formation and the dark-matter problem.
[ { "created": "Mon, 15 Feb 1993 16:15:43 GMT", "version": "v1" }, { "created": "Thu, 18 Feb 1993 18:10:27 GMT", "version": "v2" } ]
2009-10-22
[ [ "Kaiser", "N.", "" ], [ "Malaney", "R. A.", "" ], [ "Starkman", "G. D.", "" ] ]
Recently, Madsen has argued that relativistic decays of massive neutrinos into lighter fermions and bosons may lead, via thermalization, to the formation of a Bose condensate. If correct, this could generate mixed hot and cold dark matter, with important consequences for structure formation. From a detailed study of such decays, we arrive at substantially different conclusions; for a wide range of masses and decay times, we find that stimulated emission of bosons dominates the decay. This phenomenon can best be described as a neutrino laser, pumped by the QCD phase transition. We discuss the implications for structure formation and the dark-matter problem.
1812.04858
Zalak Shah
Zalak Shah, Keval Gandhi, Ajay Kumar Rai
Spectroscopy of light $N^{*}$ baryons
8 pages, 2 Figures, to be published in Chinese Physics C
Chinese Physics C 43(3):034102 2019
10.1088/1674-1137/43/3/034102
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the masses of N baryon upto 3300 MeV. The radial and orbital excited states are determined using hypercentral constituent quark model with first order correction. The obtained masses are compared with experimental results and other theoretical prediction. The Regge Trajectories are also determined in (n, $M^2$) and (J, $M^2$) planes. Moreover, the magnetic moments for $J^{P}= \frac{1}{2}^{+}, \frac{1}{2}^{-}$ are calculated. We also calculate the $N\pi$ decay width of excited nucleons.
[ { "created": "Wed, 12 Dec 2018 09:08:47 GMT", "version": "v1" } ]
2019-05-22
[ [ "Shah", "Zalak", "" ], [ "Gandhi", "Keval", "" ], [ "Rai", "Ajay Kumar", "" ] ]
We present the masses of N baryon upto 3300 MeV. The radial and orbital excited states are determined using hypercentral constituent quark model with first order correction. The obtained masses are compared with experimental results and other theoretical prediction. The Regge Trajectories are also determined in (n, $M^2$) and (J, $M^2$) planes. Moreover, the magnetic moments for $J^{P}= \frac{1}{2}^{+}, \frac{1}{2}^{-}$ are calculated. We also calculate the $N\pi$ decay width of excited nucleons.
hep-ph/9708233
Daniele Treleani
Giorgio Calucci and Daniele Treleani
Self-Similarity of the Negative Binomial Multiplicity Distributions
10 pages, plane tex, no figures
Phys.Rev. D57 (1998) 602-605
10.1103/PhysRevD.57.602
null
hep-ph
null
The negative binomial distribution is self similar: If the spectrum over the whole rapidity range gives rise to a negative binomial, in absence of correlation and if the source is unique, also a partial range in rapidity gives rise to the same distribution. The property is not seen in experimental data, which are rather consistent with the presence of a number of independent sources. When multiplicities are very large self similarity might be used to isolate individual sources is a complex production process.
[ { "created": "Mon, 4 Aug 1997 14:14:49 GMT", "version": "v1" } ]
2009-10-30
[ [ "Calucci", "Giorgio", "" ], [ "Treleani", "Daniele", "" ] ]
The negative binomial distribution is self similar: If the spectrum over the whole rapidity range gives rise to a negative binomial, in absence of correlation and if the source is unique, also a partial range in rapidity gives rise to the same distribution. The property is not seen in experimental data, which are rather consistent with the presence of a number of independent sources. When multiplicities are very large self similarity might be used to isolate individual sources is a complex production process.
1808.05613
Edoardo Vitagliano
Oleg E. Kalashev, Alexander Kusenko and Edoardo Vitagliano
Cosmic infrared background excess from axion-like particles and implications for multi-messenger observations of blazars
11 pages, 5 figures. Several changes to match published version
Phys. Rev. D 99, 023002 (2019)
10.1103/PhysRevD.99.023002
MPP-2018-213
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first measurement of the diffuse background spectrum at 0.8-1.7 $\mu \rm{m}$ from the CIBER experiment has revealed a significant excess of the cosmic infrared background (CIB) radiation compared to the theoretically expected spectrum. We revisit the hypothesis that decays of axionlike particle (ALP) can explain this excess, extending previous analyses to the case of a warm relic population. We show that such a scenario is not excluded by anisotropy measurements nor by stellar cooling arguments. Moreover, we find that the increased extragalactic background light (EBL) does not contradict observations of blazar spectra. Furthermore, the increased EBL attenuates the diffuse TeV gamma-ray flux and alleviates the tension between the detected neutrino and gamma ray fluxes.
[ { "created": "Thu, 16 Aug 2018 17:59:52 GMT", "version": "v1" }, { "created": "Thu, 3 Jan 2019 11:31:38 GMT", "version": "v2" } ]
2019-01-04
[ [ "Kalashev", "Oleg E.", "" ], [ "Kusenko", "Alexander", "" ], [ "Vitagliano", "Edoardo", "" ] ]
The first measurement of the diffuse background spectrum at 0.8-1.7 $\mu \rm{m}$ from the CIBER experiment has revealed a significant excess of the cosmic infrared background (CIB) radiation compared to the theoretically expected spectrum. We revisit the hypothesis that decays of axionlike particle (ALP) can explain this excess, extending previous analyses to the case of a warm relic population. We show that such a scenario is not excluded by anisotropy measurements nor by stellar cooling arguments. Moreover, we find that the increased extragalactic background light (EBL) does not contradict observations of blazar spectra. Furthermore, the increased EBL attenuates the diffuse TeV gamma-ray flux and alleviates the tension between the detected neutrino and gamma ray fluxes.
1509.04016
Mukesh Kumar
Mukesh Kumar, Xifeng Ruan, Rashidul Islam, Alan S. Cornell, Max Klein, Uta Klein and Bruce Mellado
Probing anomalous couplings using di-Higgs production in electron-proton collisions
null
Physics Letters B 764 (2017) 247-253
10.1016/j.physletb.2016.11.039
WITS-MITP 019
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A proposed high energy Future Circular Hadron-Electron Collider would provide sufficient energy in a clean environment to probe di-Higgs production. Using this channel we show that the azimuthal angle correlation between the missing transverse energy and the forward jet is a very good probe for the non-standard $hhh$ and $hhWW$ couplings. We give the exclusion limits on these couplings as a function of integrated luminosity at a $95$\% C.L. using the fiducial cross sections. With appropriate error fitting methodology we find that the Higgs boson self coupling could be measured to be $g^{(1)}_{hhh} = 1.00^{+0.24(0.14)}_{-0.17(0.12)}$ of its expected Standard Model value at $\sqrt s = 3.5(5.0)$ TeV for an ultimate 10 ab$^{-1}$ of integrated luminosity.
[ { "created": "Mon, 14 Sep 2015 10:15:06 GMT", "version": "v1" }, { "created": "Sat, 19 Nov 2016 09:09:42 GMT", "version": "v2" }, { "created": "Wed, 30 Nov 2016 21:05:16 GMT", "version": "v3" } ]
2016-12-02
[ [ "Kumar", "Mukesh", "" ], [ "Ruan", "Xifeng", "" ], [ "Islam", "Rashidul", "" ], [ "Cornell", "Alan S.", "" ], [ "Klein", "Max", "" ], [ "Klein", "Uta", "" ], [ "Mellado", "Bruce", "" ] ]
A proposed high energy Future Circular Hadron-Electron Collider would provide sufficient energy in a clean environment to probe di-Higgs production. Using this channel we show that the azimuthal angle correlation between the missing transverse energy and the forward jet is a very good probe for the non-standard $hhh$ and $hhWW$ couplings. We give the exclusion limits on these couplings as a function of integrated luminosity at a $95$\% C.L. using the fiducial cross sections. With appropriate error fitting methodology we find that the Higgs boson self coupling could be measured to be $g^{(1)}_{hhh} = 1.00^{+0.24(0.14)}_{-0.17(0.12)}$ of its expected Standard Model value at $\sqrt s = 3.5(5.0)$ TeV for an ultimate 10 ab$^{-1}$ of integrated luminosity.
hep-ph/0201268
Anupam Mazumdar
Anupam Mazumdar, Rouzbeh Allahverdi, Kari Enqvist, Abdel P\'erez-Lorenzana
Baryogenesis in models with large extra dimensions
11 pages, contribution to COSMO-01 conference
null
null
null
hep-ph
null
We describe how difficult it is to realise baryogenesis in models where the fundamental scale in nature is as low as TeV. The problem becomes even more challenging if we assume that there are only {\it two} extra compact spatial dimensions, because thermal history of such a Universe is strongly constrained by various cosmological and astrophysical bounds which translate the maximal temperature of the Universe which must not exceed $\sim {\cal O}(10)$MeV. This simply reiterates that the observed baryon asymmetry must be synthesised just above the nucleosynthesis scale. In this talk we address how to construct a simple model which can overcome this challenge.
[ { "created": "Tue, 29 Jan 2002 14:52:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mazumdar", "Anupam", "" ], [ "Allahverdi", "Rouzbeh", "" ], [ "Enqvist", "Kari", "" ], [ "Pérez-Lorenzana", "Abdel", "" ] ]
We describe how difficult it is to realise baryogenesis in models where the fundamental scale in nature is as low as TeV. The problem becomes even more challenging if we assume that there are only {\it two} extra compact spatial dimensions, because thermal history of such a Universe is strongly constrained by various cosmological and astrophysical bounds which translate the maximal temperature of the Universe which must not exceed $\sim {\cal O}(10)$MeV. This simply reiterates that the observed baryon asymmetry must be synthesised just above the nucleosynthesis scale. In this talk we address how to construct a simple model which can overcome this challenge.
hep-ph/0209014
Y. Y. Keum
Y.Y. Keum and A.I. Sanda
Possible Large Direct CP Violations in Charmless B-Decays
18 pages, latex, 8 figures and 8 tables, typos corrected and added more tables and references. Presented at the 3rd workshop on Higher Luminosity B Factory, 6-7 August 2002, Kanagawa, Japan; Submitted to Phys. Rev. D
Phys.Rev.D67:054009,2003
10.1103/PhysRevD.67.054009
DPNU-02-29
hep-ph
null
We discuss the perturbative QCD approach for the exclusive two body B-meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on factorization approach. We show numerical results which are compatible with present experimantal data for the charmless B-meson decays. Specailly we predict the possibility of large direct CP violation effects in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm7 %)$ and $B^0\to K^{+}\pi^{-}$ $(-17\pm5%)$. In the last section we investigate two methods to determine the weak phases $\phi_2$ and $\phi_3$ from $B \to \pi\pi,K\pi$ processes. We obtain bounds on $\phi_2$ and $\phi_3$ from present experimental measurements.
[ { "created": "Mon, 2 Sep 2002 10:47:46 GMT", "version": "v1" }, { "created": "Thu, 3 Oct 2002 10:46:01 GMT", "version": "v2" } ]
2014-11-17
[ [ "Keum", "Y. Y.", "" ], [ "Sanda", "A. I.", "" ] ]
We discuss the perturbative QCD approach for the exclusive two body B-meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on factorization approach. We show numerical results which are compatible with present experimantal data for the charmless B-meson decays. Specailly we predict the possibility of large direct CP violation effects in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm7 %)$ and $B^0\to K^{+}\pi^{-}$ $(-17\pm5%)$. In the last section we investigate two methods to determine the weak phases $\phi_2$ and $\phi_3$ from $B \to \pi\pi,K\pi$ processes. We obtain bounds on $\phi_2$ and $\phi_3$ from present experimental measurements.
2404.10066
Hailin Xu
Timon Emken, Rouven Essig, Hailin Xu
Solar reflection of dark matter with dark-photon mediators
40 pages, 23 figures including appendices and references
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the scattering of low-mass halo dark-matter particles in the hot plasma of the Sun, focusing on dark matter that interact with ordinary matter through a dark-photon mediator. The resulting ``solar-reflected'' dark matter (SRDM) component contains high-velocity particles, which significantly extend the sensitivity of terrestrial direct-detection experiments to sub-MeV dark-matter masses. We use a detailed Monte-Carlo simulation to model the propagation and scattering of dark-matter particles in the Sun, including thermal effects, with special emphasis on ultralight dark-photon mediators. We study the properties of the SRDM flux, obtain exclusion limits from various direct-detection experiments, and provide projections for future experiments, focusing especially on those with silicon and xenon targets. We find that proposed future experiments with xenon and silicon targets can probe the entire ``freeze-in benchmark,'' in which dark matter is coupled to an ultralight dark photon, including dark-matter masses as low as $\mathcal{O}$(keV). Our simulations and SRDM fluxes are publicly available.
[ { "created": "Mon, 15 Apr 2024 18:14:54 GMT", "version": "v1" } ]
2024-04-17
[ [ "Emken", "Timon", "" ], [ "Essig", "Rouven", "" ], [ "Xu", "Hailin", "" ] ]
We consider the scattering of low-mass halo dark-matter particles in the hot plasma of the Sun, focusing on dark matter that interact with ordinary matter through a dark-photon mediator. The resulting ``solar-reflected'' dark matter (SRDM) component contains high-velocity particles, which significantly extend the sensitivity of terrestrial direct-detection experiments to sub-MeV dark-matter masses. We use a detailed Monte-Carlo simulation to model the propagation and scattering of dark-matter particles in the Sun, including thermal effects, with special emphasis on ultralight dark-photon mediators. We study the properties of the SRDM flux, obtain exclusion limits from various direct-detection experiments, and provide projections for future experiments, focusing especially on those with silicon and xenon targets. We find that proposed future experiments with xenon and silicon targets can probe the entire ``freeze-in benchmark,'' in which dark matter is coupled to an ultralight dark photon, including dark-matter masses as low as $\mathcal{O}$(keV). Our simulations and SRDM fluxes are publicly available.
hep-ph/9811498
Otto Kong
M. Bisset, O.C.W. Kong, C. Macesanu, and L.H. Orr (Rochester U.)
Supersymmetry without R-parity : Constraints from Leptonic Phenomenology
56 pages Revtex with figures incorporated; typos (including transcription typo in Table II) and minor corrections; proof-read version, to appear in Phys. Rev. D
Phys.Rev. D62 (2000) 035001
10.1103/PhysRevD.62.035001
UR-1524,TUIMP-TH-98/101
hep-ph
null
R-parity conservation is an {\it ad hoc} assumption in the most popular version of the supersymmetric standard model. Most studies of models which do allow for R-parity violation have been restricted to various limiting scenarios. The single-VEV parametrization used in this paper provides a workable framework to analyze phenomenology of the most general theory of SUSY without R-parity. We perform a comprehensive study of leptonic phenomenology at tree-level. Experimental constraints on various processes are studied individually and then combined to yield regions of admissible parameter space. In particular, we show that large R-parity violating bilinear couplings are not ruled out, especially for large $\tan\beta$.
[ { "created": "Sat, 28 Nov 1998 00:30:21 GMT", "version": "v1" }, { "created": "Wed, 9 Dec 1998 22:06:06 GMT", "version": "v2" }, { "created": "Sat, 18 Mar 2000 06:16:31 GMT", "version": "v3" }, { "created": "Mon, 24 Apr 2000 06:51:55 GMT", "version": "v4" } ]
2009-10-31
[ [ "Bisset", "M.", "", "Rochester U." ], [ "Kong", "O. C. W.", "", "Rochester U." ], [ "Macesanu", "C.", "", "Rochester U." ], [ "Orr", "L. H.", "", "Rochester U." ] ]
R-parity conservation is an {\it ad hoc} assumption in the most popular version of the supersymmetric standard model. Most studies of models which do allow for R-parity violation have been restricted to various limiting scenarios. The single-VEV parametrization used in this paper provides a workable framework to analyze phenomenology of the most general theory of SUSY without R-parity. We perform a comprehensive study of leptonic phenomenology at tree-level. Experimental constraints on various processes are studied individually and then combined to yield regions of admissible parameter space. In particular, we show that large R-parity violating bilinear couplings are not ruled out, especially for large $\tan\beta$.
1412.8367
Micha{\AA} Szleper
Micha{\l} Szleper
The Higgs boson and the physics of $WW$ scattering before and after Higgs discovery
ISBN 978-83-934358-7-6, 166 pages, v2 - some references added/updated
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work presents a comprehensive overview of the physics of vector boson scattering (VBS) in the dawn of Run 2 of the Large Hadron Collider (LHC). Recalled here are some of its most basic physics principles, the historical relation between vector boson scattering and the Higgs boson, then discussed is the physics of VBS processes after Higgs discovery, and the prospects for future VBS measurements at the LHC and beyond. This monograph reviews the work of many people, including previously published theoretical work as well as experimental results, but also contains a portion of original simulation-based studies that have not been published before.
[ { "created": "Mon, 29 Dec 2014 15:14:02 GMT", "version": "v1" }, { "created": "Thu, 5 Mar 2015 16:08:18 GMT", "version": "v2" } ]
2016-08-08
[ [ "Szleper", "Michał", "" ] ]
This work presents a comprehensive overview of the physics of vector boson scattering (VBS) in the dawn of Run 2 of the Large Hadron Collider (LHC). Recalled here are some of its most basic physics principles, the historical relation between vector boson scattering and the Higgs boson, then discussed is the physics of VBS processes after Higgs discovery, and the prospects for future VBS measurements at the LHC and beyond. This monograph reviews the work of many people, including previously published theoretical work as well as experimental results, but also contains a portion of original simulation-based studies that have not been published before.
2201.09980
Aftab Ahmad A
Aftab Ahmad and Ali Murad
Color-flavor dependence of the Nambu-Jona-Lasinio model and QCD phase diagram
22 pages, 21 figures
null
10.1088/1674-1137/ac6cd8
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We study the dynamical chiral symmetry breaking/restoration for the various numbers of light quarks flavors $N_f$ and colors $N_c$, using the Nambu-Jona-Lasinio (NJL) model of quarks, dressed with a color-flavor dependence of effective coupling. Initially, we set $N_f = 2$, and varying the number of colors $N_c$, we find that the dynamical chiral symmetry is broken when $N_c$ exceeds to its critical value $N^{c}_{c}\approx2.2$. Secondly, we take $N_c = 3$, and varying $N_f$, we observed that the dynamical chiral symmetry is restored when $N_f$ reaches to its critical value $N^{c}_{f}\approx8$. The strong interplay observed between $N_c$ and $N_f$, i.e., $N_c$ anti-screens the strong interactions by strengthening the dynamical mass and quark-antiquark condensate, while $N_f$ screens the strong interaction by suppressing both the parameters. We further sketch the quantum chromodynamics (QCD) phase diagram at finite temperature $T$ and quark chemical potential $\mu$ for various $N_c$ and $N_f$. At finite $T$ and $\mu$, we observed that the critical number of colors $N^{c}_c$ enhances while the critical number of flavors $N^{c}_f$ suppresses as $T$ and $\mu$ increases. Of course, the parameters $T$ and $\mu$ produce the screening effect. Consequently, the critical temperature $T_c$, $\mu_c$ and co-ordinates of the critical endpoint $(T^{E}_c,\mu^{E}_c)$ in the QCD phase diagram enhances as $N_c$ increases while suppresses when $N_f$ increases. Our findings agree with the Lattice QCD and Schwinger-Dyson equations predictions.
[ { "created": "Mon, 24 Jan 2022 22:17:35 GMT", "version": "v1" } ]
2022-08-03
[ [ "Ahmad", "Aftab", "" ], [ "Murad", "Ali", "" ] ]
We study the dynamical chiral symmetry breaking/restoration for the various numbers of light quarks flavors $N_f$ and colors $N_c$, using the Nambu-Jona-Lasinio (NJL) model of quarks, dressed with a color-flavor dependence of effective coupling. Initially, we set $N_f = 2$, and varying the number of colors $N_c$, we find that the dynamical chiral symmetry is broken when $N_c$ exceeds to its critical value $N^{c}_{c}\approx2.2$. Secondly, we take $N_c = 3$, and varying $N_f$, we observed that the dynamical chiral symmetry is restored when $N_f$ reaches to its critical value $N^{c}_{f}\approx8$. The strong interplay observed between $N_c$ and $N_f$, i.e., $N_c$ anti-screens the strong interactions by strengthening the dynamical mass and quark-antiquark condensate, while $N_f$ screens the strong interaction by suppressing both the parameters. We further sketch the quantum chromodynamics (QCD) phase diagram at finite temperature $T$ and quark chemical potential $\mu$ for various $N_c$ and $N_f$. At finite $T$ and $\mu$, we observed that the critical number of colors $N^{c}_c$ enhances while the critical number of flavors $N^{c}_f$ suppresses as $T$ and $\mu$ increases. Of course, the parameters $T$ and $\mu$ produce the screening effect. Consequently, the critical temperature $T_c$, $\mu_c$ and co-ordinates of the critical endpoint $(T^{E}_c,\mu^{E}_c)$ in the QCD phase diagram enhances as $N_c$ increases while suppresses when $N_f$ increases. Our findings agree with the Lattice QCD and Schwinger-Dyson equations predictions.