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1911.12956
Jihn E. Kim
Jihn E. Kim
Gauge Hierarchy
5 LaTeX pages with 6 figures. Talk presented at 14th Asia-Pacific Physics Conference, Kuching, Borneo, Malaysia, 18-21 November 2019
null
10.1063/5.0036965
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The chirality is the key for our world. In this scheme, I present a solution of the long standing gauge hierarchy problem with a hidden sector SU(5)$'$ with representations $\overline{\bf 10}\oplus \overline{\bf 5}\oplus 2\cdot{\bf 5}$. Sideway remarks are on {\it NATURAL HILLTOP} inflation and a bound on the QCD angle $\bar\theta$.
[ { "created": "Fri, 29 Nov 2019 05:33:10 GMT", "version": "v1" }, { "created": "Fri, 6 Dec 2019 04:14:28 GMT", "version": "v2" } ]
2024-06-19
[ [ "Kim", "Jihn E.", "" ] ]
The chirality is the key for our world. In this scheme, I present a solution of the long standing gauge hierarchy problem with a hidden sector SU(5)$'$ with representations $\overline{\bf 10}\oplus \overline{\bf 5}\oplus 2\cdot{\bf 5}$. Sideway remarks are on {\it NATURAL HILLTOP} inflation and a bound on the QCD angle $\bar\theta$.
hep-ph/9506223
Shmuel Gurevitz
S. A. Gurvitz
The ratio $F_2^n/F_2^p$ from the analysis of data using a new scaling variable
8 pages, 4 figures
null
null
WIS-95/22/May-PH
hep-ph
null
We analyze the proton and deuteron structure functions at large $x$ using a recently introduced scaling variable $\bar x$. This variable includes power corrections to $x$-scaling, and thus allows us to reach the Bjorken limit at moderate $Q^2$. Using available data we extract the ratio $F_2^n(x)/F_2^p(x)$ for $x\leq 0.85$. Contrary to earlier expectations this ratio tends to the value $\sim$2/3 for $x\to 1$, which corresponds to the quark model prediction for equal distributions of valence quarks.
[ { "created": "Fri, 2 Jun 1995 11:46:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gurvitz", "S. A.", "" ] ]
We analyze the proton and deuteron structure functions at large $x$ using a recently introduced scaling variable $\bar x$. This variable includes power corrections to $x$-scaling, and thus allows us to reach the Bjorken limit at moderate $Q^2$. Using available data we extract the ratio $F_2^n(x)/F_2^p(x)$ for $x\leq 0.85$. Contrary to earlier expectations this ratio tends to the value $\sim$2/3 for $x\to 1$, which corresponds to the quark model prediction for equal distributions of valence quarks.
hep-ph/0007006
Howard E. Haber
Howard E. Haber, Maria J. Herrero, Heather E. Logan, Siannah Penaranda, Stefano Rigolin and David Temes
SUSY-QCD corrections to the MSSM $h^0 b \bar b$ vertex in the decoupling limit
27 pages, 7 figures and 1 table in LaTeX2e format; with a few minor changes and updated references
Phys.Rev.D63:055004,2001
10.1103/PhysRevD.63.055004
null
hep-ph
null
We analyze the supersymmetric (SUSY) QCD contribution to the $h^0 b \bar{b}$ coupling at one loop in the Minimal Supersymmetric Model (MSSM) in the decoupling limit. Analytic expressions in the large SUSY mass region are derived and the decoupling behavior of the corrections is examined in various limiting cases, where some or all of the SUSY mass parameters become large. We show that in the decoupling limit of large SUSY mass parameters and large CP-odd Higgs mass, the $h^0 b \bar b$ coupling approaches its Standard Model value at one loop. However, the onset of decoupling is delayed when $\tan\beta$ is large. In addition, the one-loop SUSY-QCD corrections decouple if the masses of either the bottom squarks or the gluino are separately taken large; although the approach to decoupling is significantly slower in the latter case.
[ { "created": "Mon, 3 Jul 2000 01:19:39 GMT", "version": "v1" }, { "created": "Wed, 12 Jul 2000 19:42:17 GMT", "version": "v2" } ]
2011-03-23
[ [ "Haber", "Howard E.", "" ], [ "Herrero", "Maria J.", "" ], [ "Logan", "Heather E.", "" ], [ "Penaranda", "Siannah", "" ], [ "Rigolin", "Stefano", "" ], [ "Temes", "David", "" ] ]
We analyze the supersymmetric (SUSY) QCD contribution to the $h^0 b \bar{b}$ coupling at one loop in the Minimal Supersymmetric Model (MSSM) in the decoupling limit. Analytic expressions in the large SUSY mass region are derived and the decoupling behavior of the corrections is examined in various limiting cases, where some or all of the SUSY mass parameters become large. We show that in the decoupling limit of large SUSY mass parameters and large CP-odd Higgs mass, the $h^0 b \bar b$ coupling approaches its Standard Model value at one loop. However, the onset of decoupling is delayed when $\tan\beta$ is large. In addition, the one-loop SUSY-QCD corrections decouple if the masses of either the bottom squarks or the gluino are separately taken large; although the approach to decoupling is significantly slower in the latter case.
1205.0506
Stephen King
S. F. King
Tri-bimaximal-Cabibbo Mixing
16 pages. References added, minor changes
null
10.1016/j.physletb.2012.10.028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent measurements of the lepton mixing angle $\theta_{13}$ by the Daya Bay and RENO reactor experiments are consistent with the relationship $\theta_{13}\approx \theta_C/\sqrt{2}$ where $ \theta_C$ is the Cabibbo angle. We propose Tri-bimaximal-Cabibbo (TBC) mixing, in which $\sin \theta_{13}= \sin \theta_C/\sqrt{2}$, $\sin \theta_{23}= 1/\sqrt{2}$ and $\sin \theta_{12}= 1/\sqrt{3}$. We show that TBC mixing may arise approximately from Tri-bimaximal, Bi-maximal or Golden Ratio neutrino mixing, together with Cabibbo-like charged lepton corrections arising from a Pati-Salam gauge group, leading to predictions for the CP-violating phase of $\delta \approx \pm 90^o, \pm 180^o, \pm 75^o$, respectively. Alternatively, we show that TBC neutrino mixing may realised accurately using the type I see-saw mechanism with partially constrained sequential right-handed neutrino dominance, assuming a family symmetry which is broken by a flavon common to quarks and neutrinos.
[ { "created": "Wed, 2 May 2012 17:55:11 GMT", "version": "v1" }, { "created": "Mon, 7 May 2012 08:21:46 GMT", "version": "v2" } ]
2015-06-05
[ [ "King", "S. F.", "" ] ]
Recent measurements of the lepton mixing angle $\theta_{13}$ by the Daya Bay and RENO reactor experiments are consistent with the relationship $\theta_{13}\approx \theta_C/\sqrt{2}$ where $ \theta_C$ is the Cabibbo angle. We propose Tri-bimaximal-Cabibbo (TBC) mixing, in which $\sin \theta_{13}= \sin \theta_C/\sqrt{2}$, $\sin \theta_{23}= 1/\sqrt{2}$ and $\sin \theta_{12}= 1/\sqrt{3}$. We show that TBC mixing may arise approximately from Tri-bimaximal, Bi-maximal or Golden Ratio neutrino mixing, together with Cabibbo-like charged lepton corrections arising from a Pati-Salam gauge group, leading to predictions for the CP-violating phase of $\delta \approx \pm 90^o, \pm 180^o, \pm 75^o$, respectively. Alternatively, we show that TBC neutrino mixing may realised accurately using the type I see-saw mechanism with partially constrained sequential right-handed neutrino dominance, assuming a family symmetry which is broken by a flavon common to quarks and neutrinos.
hep-ph/9309263
Fred Hawes
Frederick T. Hawes, Craig D. Roberts and Anthony G. Williams
Dynamical chiral symmetry breaking and confinement with an infrared-vanishing gluon propagator?
21 Pages including 4 PostScript figures uuencoded at the end of the file. Replacement: slight changes of wording and emphasis. ADP-93-215/T133, ANL-PHY-7599-TH-93, FSU-SCRI-93-108, REVTEX 3.0
Phys.Rev.D49:4683-4693,1994
10.1103/PhysRevD.49.4683
null
hep-ph nucl-th
null
We study a model Dyson-Schwinger equation for the quark propagator closed using an {\it Ansatz} for the gluon propagator of the form \mbox{$D(q) \sim q^2/[(q^2)^2 + b^4]$} and two {\it Ans\"{a}tze} for the quark-gluon vertex: the minimal Ball-Chiu and the modified form suggested by Curtis and Pennington. Using the quark condensate as an order parameter, we find that there is a critical value of $b=b_c$ such that the model does not support dynamical chiral symmetry breaking for $b>b_c$. We discuss and apply a confinement test which suggests that, for all values of $b$, the quark propagator in the model {\bf is not} confining. Together these results suggest that this Ansatz for the gluon propagator is inadequate as a model since it does not yield the expected behaviour of QCD.
[ { "created": "Tue, 14 Sep 1993 20:11:30 GMT", "version": "v1" }, { "created": "Tue, 18 Jan 1994 18:16:55 GMT", "version": "v2" } ]
2010-03-04
[ [ "Hawes", "Frederick T.", "" ], [ "Roberts", "Craig D.", "" ], [ "Williams", "Anthony G.", "" ] ]
We study a model Dyson-Schwinger equation for the quark propagator closed using an {\it Ansatz} for the gluon propagator of the form \mbox{$D(q) \sim q^2/[(q^2)^2 + b^4]$} and two {\it Ans\"{a}tze} for the quark-gluon vertex: the minimal Ball-Chiu and the modified form suggested by Curtis and Pennington. Using the quark condensate as an order parameter, we find that there is a critical value of $b=b_c$ such that the model does not support dynamical chiral symmetry breaking for $b>b_c$. We discuss and apply a confinement test which suggests that, for all values of $b$, the quark propagator in the model {\bf is not} confining. Together these results suggest that this Ansatz for the gluon propagator is inadequate as a model since it does not yield the expected behaviour of QCD.
hep-ph/9409271
Vladimir Braun
I.I. Balitsky and V.M. Braun
Instanton-induced production of jets with large transverse momentum in QCD
LATEX, requires espcrc2.sty file, appended at the end. (Invited talk presented by V. Braun at the conference ``QCD-94'', Montpellier, France, July 7 -13, 1994), MPI-PhT/94-59
Nucl.Phys.Proc.Suppl. 39BC (1995) 166-168
10.1016/0920-5632(95)00065-H
null
hep-ph
null
We consider the instanton-induced cross section for production of a gluon jet with large transverse momentum in QCD and point out that Mueller's corrections corresponding to the rescattering of hard quanta are likely to remove contributions of large instantons, making this cross section well defined. Some speculations about possible phenomenological signatures are presented.
[ { "created": "Fri, 9 Sep 1994 16:55:06 GMT", "version": "v1" } ]
2009-10-28
[ [ "Balitsky", "I. I.", "" ], [ "Braun", "V. M.", "" ] ]
We consider the instanton-induced cross section for production of a gluon jet with large transverse momentum in QCD and point out that Mueller's corrections corresponding to the rescattering of hard quanta are likely to remove contributions of large instantons, making this cross section well defined. Some speculations about possible phenomenological signatures are presented.
0911.4335
Yuichiro Kiyo
C. Anzai, Y. Kiyo and Y. Sumino
Static QCD potential at three-loop order
4 pages, 2 figures
Phys.Rev.Lett.104:112003,2010
10.1103/PhysRevLett.104.112003
TU-856, KEK-TH-1339
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the purely gluonic contribution to the static QCD potential at three--loop order. This completes the computation of the static potential at this order.
[ { "created": "Mon, 23 Nov 2009 10:14:43 GMT", "version": "v1" } ]
2010-04-06
[ [ "Anzai", "C.", "" ], [ "Kiyo", "Y.", "" ], [ "Sumino", "Y.", "" ] ]
We compute the purely gluonic contribution to the static QCD potential at three--loop order. This completes the computation of the static potential at this order.
1311.0052
Marcos Garcia Garcia
Jason L. Evans, Marcos A.G. Garcia, Keith A. Olive
The Moduli and Gravitino (non)-Problems in Models with Strongly Stabilized Moduli
29 pages, 2 figures
null
10.1088/1475-7516/2014/03/022
UMN--TH--3311/13, FTPI--MINN--13/39
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In gravity mediated models and in particular in models with strongly stabilized moduli, there is a natural hierarchy between gaugino masses, the gravitino mass and moduli masses: $m_{1/2} \ll m_{3/2} \ll m_{\phi}$. Given this hierarchy, we show that 1) moduli problems associated with excess entropy production from moduli decay and 2) problems associated with moduli/gravitino decays to neutralinos are non-existent. Placed in an inflationary context, we show that the amplitude of moduli oscillations are severely limited by strong stabilization. Moduli oscillations may then never come to dominate the energy density of the Universe. As a consequence, moduli decay to gravitinos and their subsequent decay to neutralinos need not overpopulate the cold dark matter density.
[ { "created": "Thu, 31 Oct 2013 22:31:54 GMT", "version": "v1" } ]
2015-06-17
[ [ "Evans", "Jason L.", "" ], [ "Garcia", "Marcos A. G.", "" ], [ "Olive", "Keith A.", "" ] ]
In gravity mediated models and in particular in models with strongly stabilized moduli, there is a natural hierarchy between gaugino masses, the gravitino mass and moduli masses: $m_{1/2} \ll m_{3/2} \ll m_{\phi}$. Given this hierarchy, we show that 1) moduli problems associated with excess entropy production from moduli decay and 2) problems associated with moduli/gravitino decays to neutralinos are non-existent. Placed in an inflationary context, we show that the amplitude of moduli oscillations are severely limited by strong stabilization. Moduli oscillations may then never come to dominate the energy density of the Universe. As a consequence, moduli decay to gravitinos and their subsequent decay to neutralinos need not overpopulate the cold dark matter density.
hep-ph/9908284
Hagen Kleinert
H. Kleinert, B. Van den Bossche
No Massless Pions in Nambu-Jona-Lasinio Model due to Chiral Fluctuations
Version 2 contains several improvements. Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of paper also at http://www.physik.fu-berlin.de/~kleinert/296
null
null
null
hep-ph
null
In contrast to common belief, the chirally symmetric Nambu--Jona-Lasinio model does not contain massless pions, due to strong chiral fluctuations. Although quarks acquire spontaneously a nonzero constituent mass $M$, pions have a nonzero mass equal to the mass of $ \s $-mesons, both being of the order of $M$. This result is found in several cutoff schemes. Our derivation is nonperturbative, but involves a simple approximation (London limit) which should, however, receive only quantitative, no qualitative corrections.
[ { "created": "Fri, 6 Aug 1999 14:41:49 GMT", "version": "v1" }, { "created": "Sun, 24 Oct 1999 08:28:17 GMT", "version": "v2" } ]
2007-05-23
[ [ "Kleinert", "H.", "" ], [ "Bossche", "B. Van den", "" ] ]
In contrast to common belief, the chirally symmetric Nambu--Jona-Lasinio model does not contain massless pions, due to strong chiral fluctuations. Although quarks acquire spontaneously a nonzero constituent mass $M$, pions have a nonzero mass equal to the mass of $ \s $-mesons, both being of the order of $M$. This result is found in several cutoff schemes. Our derivation is nonperturbative, but involves a simple approximation (London limit) which should, however, receive only quantitative, no qualitative corrections.
1111.7085
Kalpana Bora
Kalpana Bora
Parameter degeneracies in FNAL-Homestake LBNE setup
7 pages, 3 figures
JASS(Journal of Assam Science Society), Vol 52, No 2, p 84, 2011 (ISSN No - 0587-1921)
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
LBNE (Longbaseline Neutrino Oscillation Experiments) provide a powerful experimental setup to study sensitivities and exlcusion limits in neutrino oscillation parameter space. A longbaseline experiment is being planned, at USA, from FNAL (Fermilab National Accelerator Laboratory) to an underground laboratory at Homestake in South Dakota, at an angle of 5.84 degrees from FNAL (at a distance of 1289 km). The prospect of a new beamline towards this location from FNAL, and a 300 Kiloton water Cerenkov detector at the site is in planning stage, for the studies of the neutrino physics program. The long baseline provides sufficient matter effects for neutrino travel, and a large detrecor will help towards better statistics. In this work, we present, upto what extent, the parameter degeneracies, present in oscillation parameter space, can be resolved, using this FNAL-LBNE setup.
[ { "created": "Wed, 30 Nov 2011 09:01:13 GMT", "version": "v1" } ]
2014-06-24
[ [ "Bora", "Kalpana", "" ] ]
LBNE (Longbaseline Neutrino Oscillation Experiments) provide a powerful experimental setup to study sensitivities and exlcusion limits in neutrino oscillation parameter space. A longbaseline experiment is being planned, at USA, from FNAL (Fermilab National Accelerator Laboratory) to an underground laboratory at Homestake in South Dakota, at an angle of 5.84 degrees from FNAL (at a distance of 1289 km). The prospect of a new beamline towards this location from FNAL, and a 300 Kiloton water Cerenkov detector at the site is in planning stage, for the studies of the neutrino physics program. The long baseline provides sufficient matter effects for neutrino travel, and a large detrecor will help towards better statistics. In this work, we present, upto what extent, the parameter degeneracies, present in oscillation parameter space, can be resolved, using this FNAL-LBNE setup.
1611.01533
Roman Pasechnik
Roman Pasechnik and Michal \v{S}umbera
Phenomenological Review on Quark-Gluon Plasma: Concepts vs. Observations
64 pages, 29 figures; a new subsection 4.4.2 and a few references have been added; minor changes; published version
Universe 3 (2017) 7
10.3390/universe3010007
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this review, we present an up-to-date phenomenological summary of research developments in the physics of the Quark--Gluon Plasma (QGP). A short historical perspective and theoretical motivation for this rapidly developing field of contemporary particle physics is provided. In addition, we introduce and discuss the role of the quantum chromodynamics (QCD) ground state, non-perturbative and lattice QCD results on the QGP properties, as well as the transport models used to make a connection between theory and experiment. The experimental part presents the selected results on bulk observables, hard and penetrating probes obtained in the ultra-relativistic heavy-ion experiments carried out at the Brookhaven National Laboratory Relativistic Heavy Ion Collider (BNL RHIC) and CERN Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC) accelerators. We also give a brief overview of new developments related to the ongoing searches of the QCD critical point and to the collectivity in small ($p+p$ and $p+A$) systems.
[ { "created": "Fri, 4 Nov 2016 20:58:37 GMT", "version": "v1" }, { "created": "Tue, 22 Nov 2016 21:41:33 GMT", "version": "v2" }, { "created": "Thu, 26 Jan 2017 19:10:07 GMT", "version": "v3" } ]
2017-01-30
[ [ "Pasechnik", "Roman", "" ], [ "Šumbera", "Michal", "" ] ]
In this review, we present an up-to-date phenomenological summary of research developments in the physics of the Quark--Gluon Plasma (QGP). A short historical perspective and theoretical motivation for this rapidly developing field of contemporary particle physics is provided. In addition, we introduce and discuss the role of the quantum chromodynamics (QCD) ground state, non-perturbative and lattice QCD results on the QGP properties, as well as the transport models used to make a connection between theory and experiment. The experimental part presents the selected results on bulk observables, hard and penetrating probes obtained in the ultra-relativistic heavy-ion experiments carried out at the Brookhaven National Laboratory Relativistic Heavy Ion Collider (BNL RHIC) and CERN Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC) accelerators. We also give a brief overview of new developments related to the ongoing searches of the QCD critical point and to the collectivity in small ($p+p$ and $p+A$) systems.
hep-ph/0506037
Ikaros Bigi
I. I. Bigi and A.I. Sanda
A "Known" CP Asymmetry in $\tau$ Decays
5 pages, LATEX, no figures; dedicated to our late colleague and friend P. Kabir; Prodded by our colleagues J. Rosner and Y. Grossman we have clarified how the CPT constraint of equal lifetimes is implemented."
Phys.Lett. B625 (2005) 47-52
10.1016/j.physletb.2005.08.033
UND-HEP-05-BIG02
hep-ph
null
We point out that dynamics known from the observed CP violation in $K_L\to \pi^{\mp}l^{\pm}\nu$ generate a CP asymmetry of $3.3\cdot 10^{-3}$ in $\tau^{\pm} \to \nu K_L\pi^{\pm}$. CPT invariance requires the same asymmetry in the more approachable transitions $\tau^{\pm} \to \nu K_S\pi^{\pm}$. While little new can be learnt from this fact, it has to be accounted for, since CP asymmetries in $\tau \to \nu K\pi$ channels are prime candidates for revealing the intervention of New Physics. This `known' CP asymmetry provides a very useful calibration point in such searches. It also provides a test of CPT symmetry (as well as the $\Delta Q = \Delta S$ selection rule).
[ { "created": "Sat, 4 Jun 2005 15:17:03 GMT", "version": "v1" }, { "created": "Wed, 27 Jul 2005 20:32:40 GMT", "version": "v2" } ]
2010-04-05
[ [ "Bigi", "I. I.", "" ], [ "Sanda", "A. I.", "" ] ]
We point out that dynamics known from the observed CP violation in $K_L\to \pi^{\mp}l^{\pm}\nu$ generate a CP asymmetry of $3.3\cdot 10^{-3}$ in $\tau^{\pm} \to \nu K_L\pi^{\pm}$. CPT invariance requires the same asymmetry in the more approachable transitions $\tau^{\pm} \to \nu K_S\pi^{\pm}$. While little new can be learnt from this fact, it has to be accounted for, since CP asymmetries in $\tau \to \nu K\pi$ channels are prime candidates for revealing the intervention of New Physics. This `known' CP asymmetry provides a very useful calibration point in such searches. It also provides a test of CPT symmetry (as well as the $\Delta Q = \Delta S$ selection rule).
hep-ph/0612101
Ling-Lie Chau
Ling-Lie Chau
Phase Direct CP Violations and General Mixing Matrices
4 pages
Phys.Lett.B651:293-297,2007
10.1016/j.physletb.2007.04.016
null
hep-ph
null
I formulate expressions for amplitudes suitable for quantifying both modulus and phase direct CP violations. They result in M\"{o}bius transformation (MT) relations, which provide encouraging information for the search of direct CP violations in general. I apply the formulation to calculate the measurements of phase direct CP violations and strong amplitudes in $B^{\mp}\to K^{\mp}\pi^{\pm}\pi^{\mp}$ by the Belle collaboration. For the formulation, I show a versatile construction procedure for $N\times N$ Cabibbo-Kobayashi-Maskawa (CKM) matrices, Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrices, and general unitary matrices. It clarifies the $3\times3$ cases and is useful for the beyond.
[ { "created": "Sat, 9 Dec 2006 05:26:58 GMT", "version": "v1" }, { "created": "Mon, 16 Apr 2007 03:25:33 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chau", "Ling-Lie", "" ] ]
I formulate expressions for amplitudes suitable for quantifying both modulus and phase direct CP violations. They result in M\"{o}bius transformation (MT) relations, which provide encouraging information for the search of direct CP violations in general. I apply the formulation to calculate the measurements of phase direct CP violations and strong amplitudes in $B^{\mp}\to K^{\mp}\pi^{\pm}\pi^{\mp}$ by the Belle collaboration. For the formulation, I show a versatile construction procedure for $N\times N$ Cabibbo-Kobayashi-Maskawa (CKM) matrices, Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrices, and general unitary matrices. It clarifies the $3\times3$ cases and is useful for the beyond.
1108.6289
Anna Skachkova
A.N.Skachkova
On lepton pair production in proton-antiproton collisions at intermediate energies and the main backgrounds
2 pages. Proceeding of XIV International Conference on Hadron Spectroscopy (hadron2011), 13-17 June 2011, Munich, Germany
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The lepton pair production via the quark-antiquark annihilation subprocess in collisions of beam antiproton with the proton target at E_beam = 14 GeV (which corresponds to the center-of-mass energy of the p pbar system E_cm = 5.3 GeV) is studied on the basis of the event sample simulated by PYTHIA6 generator and PandaRoot package. Different kinematical variables which may be useful for design of the muon system and the electromagnetic calorimeter of the detector of PANDA experiment at FAIR, as well as for the study of proton structure functions in the available x-Q2 kinematical region, are considered. The problems due to the presence of fake leptons that appear from meson decays, as well as due to the contribution of background QCD processes and minimum bias events, are also discussed. The set of cuts which allows one to separate the events with the signal lepton pairs from different kind of background events are proposed.
[ { "created": "Wed, 31 Aug 2011 16:30:53 GMT", "version": "v1" } ]
2011-09-01
[ [ "Skachkova", "A. N.", "" ] ]
The lepton pair production via the quark-antiquark annihilation subprocess in collisions of beam antiproton with the proton target at E_beam = 14 GeV (which corresponds to the center-of-mass energy of the p pbar system E_cm = 5.3 GeV) is studied on the basis of the event sample simulated by PYTHIA6 generator and PandaRoot package. Different kinematical variables which may be useful for design of the muon system and the electromagnetic calorimeter of the detector of PANDA experiment at FAIR, as well as for the study of proton structure functions in the available x-Q2 kinematical region, are considered. The problems due to the presence of fake leptons that appear from meson decays, as well as due to the contribution of background QCD processes and minimum bias events, are also discussed. The set of cuts which allows one to separate the events with the signal lepton pairs from different kind of background events are proposed.
2402.10263
Raymond Co
Patrick Barnes, Raymond T. Co, Keisuke Harigaya, and Aaron Pierce
Lepto-axiogenesis with light right-handed neutrinos
59 pages, 6 figures
null
null
LCTP-24-02, UMN-TH-4307/23, FTPI-MINN-23-27
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study lepto-axiogenesis in theories where the right-handed neutrino is light enough that its dynamics affect the determination of the baryon asymmetry. When compared with theories of high-scale lepto-axiogenesis where the Majorana neutrino mass may be treated as an effective dimension-five operator, we find that the predicted saxion mass is lower. Two distinct scenarios emerge. In the first, processes that generate the baryon asymmetry are in equilibrium down to the mass of the right-handed neutrino. In the second, the relevant processes never reach equilibrium; the baryon number freezes in. We comment on implications for supersymmetric spectra and discuss constraints on late decays of supersymmetric relics and from dark radiation. In contrast to high-scale lepto-axiogenesis, which predicts superpartners with masses of 10-100 TeV or more, we find this scenario is consistent with a wider range of superpartner masses, all the way down to current direct search bounds.
[ { "created": "Thu, 15 Feb 2024 19:00:00 GMT", "version": "v1" } ]
2024-02-19
[ [ "Barnes", "Patrick", "" ], [ "Co", "Raymond T.", "" ], [ "Harigaya", "Keisuke", "" ], [ "Pierce", "Aaron", "" ] ]
We study lepto-axiogenesis in theories where the right-handed neutrino is light enough that its dynamics affect the determination of the baryon asymmetry. When compared with theories of high-scale lepto-axiogenesis where the Majorana neutrino mass may be treated as an effective dimension-five operator, we find that the predicted saxion mass is lower. Two distinct scenarios emerge. In the first, processes that generate the baryon asymmetry are in equilibrium down to the mass of the right-handed neutrino. In the second, the relevant processes never reach equilibrium; the baryon number freezes in. We comment on implications for supersymmetric spectra and discuss constraints on late decays of supersymmetric relics and from dark radiation. In contrast to high-scale lepto-axiogenesis, which predicts superpartners with masses of 10-100 TeV or more, we find this scenario is consistent with a wider range of superpartner masses, all the way down to current direct search bounds.
0801.4639
Carlo Giunti
Carlo Giunti
Comment on the Neutrino-Mixing Interpretation of the GSI Time Anomaly
5 pages. Revised Addendum 2: Quantum effects in GSI nuclear decay are possible
null
null
null
hep-ph astro-ph hep-ex nucl-ex nucl-th
null
It is shown that neutrino mixing cannot explain the GSI time anomaly, refuting recent claims in this direction. Addendum 1: Remarks on arXiv:0801.1465. Addendum 2: Quantum effects in GSI nuclear decay.
[ { "created": "Wed, 30 Jan 2008 15:04:36 GMT", "version": "v1" }, { "created": "Tue, 4 Mar 2008 14:13:41 GMT", "version": "v2" }, { "created": "Thu, 17 Apr 2008 21:34:04 GMT", "version": "v3" } ]
2008-04-18
[ [ "Giunti", "Carlo", "" ] ]
It is shown that neutrino mixing cannot explain the GSI time anomaly, refuting recent claims in this direction. Addendum 1: Remarks on arXiv:0801.1465. Addendum 2: Quantum effects in GSI nuclear decay.
0710.4767
Ludwik Turko
L. Turko
Relativistic hydrodynamics with strangeness production
v.2 with minor editorial corrections, 7 pages, talk given on the SQM2007 conference, Levoca, June 24-29, 2007. To appear in the proceceeding: Journal of Physics G
J.Phys.G35:044019,2008
10.1088/0954-3899/35/4/044019
null
hep-ph
null
The relativistic hydrodynamic approach is used to describe production of strangeness and/or heavy quarks in ultrarelativistic heavy ion reactions. Production processes are important ingredients of dissipative effects in the hadronic liquid. Beyond viscosity also chemo- and thermo-diffusion processes are considered. This also allows to specify chemical and thermal freeze-out conditions.
[ { "created": "Thu, 25 Oct 2007 10:01:15 GMT", "version": "v1" }, { "created": "Thu, 29 Nov 2007 09:30:57 GMT", "version": "v2" } ]
2008-11-26
[ [ "Turko", "L.", "" ] ]
The relativistic hydrodynamic approach is used to describe production of strangeness and/or heavy quarks in ultrarelativistic heavy ion reactions. Production processes are important ingredients of dissipative effects in the hadronic liquid. Beyond viscosity also chemo- and thermo-diffusion processes are considered. This also allows to specify chemical and thermal freeze-out conditions.
hep-ph/0012105
MuLin Yan
Mu-Lin Yan
$K^*(892)$ Electromagnetic Mass Anomaly
tex file, 4 pages, no figures
null
null
null
hep-ph
null
Electromagnetic masses of neutral $K^*(892)$ may be larger than one of charged $K^*(892)$. It is unusual and is called $K^*$-EM-mass anomaly. We review the studies on this issue, and point out that $K^*$-mass splitting can be measured in BES accurately.
[ { "created": "Sat, 9 Dec 2000 09:28:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yan", "Mu-Lin", "" ] ]
Electromagnetic masses of neutral $K^*(892)$ may be larger than one of charged $K^*(892)$. It is unusual and is called $K^*$-EM-mass anomaly. We review the studies on this issue, and point out that $K^*$-mass splitting can be measured in BES accurately.
1910.03533
Alan D. Martin
V.A. Khoze, A.D. Martin and M.G. Ryskin
Bethe phase including proton excitations
11 pages, 5 figures, version published in Phys.Rev. D
Phys. Rev. D 101, 016018 (2020)
10.1103/PhysRevD.101.016018
IPPP/19/79
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the contribution of inelastic intermediate states (such as $p\to N^*$ excitations) to the phase between the one-photon-exchange and the `nuclear' high energy $pp$ scattering amplitudes as $t\to 0$, caused by multiphoton diagrams. It turns out to be rather small - much smaller than to have any influence on the experimental accuracy of the measurements of $\rho$, defined to be the ratio of the real to imaginary parts of the forward `nuclear' amplitude.
[ { "created": "Tue, 8 Oct 2019 16:44:49 GMT", "version": "v1" }, { "created": "Mon, 3 Feb 2020 10:46:22 GMT", "version": "v2" } ]
2020-02-05
[ [ "Khoze", "V. A.", "" ], [ "Martin", "A. D.", "" ], [ "Ryskin", "M. G.", "" ] ]
We evaluate the contribution of inelastic intermediate states (such as $p\to N^*$ excitations) to the phase between the one-photon-exchange and the `nuclear' high energy $pp$ scattering amplitudes as $t\to 0$, caused by multiphoton diagrams. It turns out to be rather small - much smaller than to have any influence on the experimental accuracy of the measurements of $\rho$, defined to be the ratio of the real to imaginary parts of the forward `nuclear' amplitude.
hep-ph/0404211
Anna Rossi
Andrea Brignole and Anna Rossi
Anatomy and Phenomenology of mu-tau Lepton Flavour Violation in the MSSM
52 Latex pages; v2: refs. added, typos corrected [eqs. (42)-(46)]
Nucl.Phys.B701:3-53,2004
10.1016/j.nuclphysb.2004.08.037
DFPD-04/TH/06
hep-ph
null
We perform a detailed analysis of several mu-tau lepton flavour violating (LFV) processes, namely tau --> mu X (X = gamma, e+ e-, mu+ mu-, rho, pi, eta, eta'), Z --> mu tau and Higgs boson decays into mu tau. First we present a model independent operator analysis relevant to such decays, then we explicitly compute the LFV operator coefficients [and (g_\mu -2)] in a general unconstrained MSSM framework, allowing slepton mass matrices to have large mu-tau entries. We systematically study the role and the interplay of dipole and non-dipole operators, showing how the rates and the mutual correlations of those LFV decays change in different regions of the MSSM parameter space.Values of the LFV branching ratios in the experimentally interesting range 10^{-9}-10^{-7} can be achieved. For at least two MSSM Higgs bosons, the branching ratio of the LFV decay into mu tau can reach values of order 10^{-4}.
[ { "created": "Fri, 23 Apr 2004 18:09:16 GMT", "version": "v1" }, { "created": "Thu, 20 May 2004 14:07:20 GMT", "version": "v2" } ]
2010-04-06
[ [ "Brignole", "Andrea", "" ], [ "Rossi", "Anna", "" ] ]
We perform a detailed analysis of several mu-tau lepton flavour violating (LFV) processes, namely tau --> mu X (X = gamma, e+ e-, mu+ mu-, rho, pi, eta, eta'), Z --> mu tau and Higgs boson decays into mu tau. First we present a model independent operator analysis relevant to such decays, then we explicitly compute the LFV operator coefficients [and (g_\mu -2)] in a general unconstrained MSSM framework, allowing slepton mass matrices to have large mu-tau entries. We systematically study the role and the interplay of dipole and non-dipole operators, showing how the rates and the mutual correlations of those LFV decays change in different regions of the MSSM parameter space.Values of the LFV branching ratios in the experimentally interesting range 10^{-9}-10^{-7} can be achieved. For at least two MSSM Higgs bosons, the branching ratio of the LFV decay into mu tau can reach values of order 10^{-4}.
hep-ph/0309231
Gon\c{c}alo Marques
P. Bicudo, G. M. Marques
Chiral Symmetry Breaking and Scalar Confinement
null
null
null
null
hep-ph
null
We address the old difficulty in accommodating the scalar quark-antiquark confining potential together with chiral symmetry breaking. We develop a quark confining potential inspired in the QCD scalar flux tube. The coupling to quarks consists in a double vector vertex. We study the Dirac and spin structure of this potential. In the limit of massless quarks the quark vertex is vector. Nevertheless symmetry breaking generates a new scalar quark vertex. In the heavy quark limit the coupling is mostly scalar. We solve the mass gap equation and find that this potential produces spontaneous chiral symmetry breaking for light quarks. The quantitative results of this model are encouraging.
[ { "created": "Fri, 19 Sep 2003 13:47:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bicudo", "P.", "" ], [ "Marques", "G. M.", "" ] ]
We address the old difficulty in accommodating the scalar quark-antiquark confining potential together with chiral symmetry breaking. We develop a quark confining potential inspired in the QCD scalar flux tube. The coupling to quarks consists in a double vector vertex. We study the Dirac and spin structure of this potential. In the limit of massless quarks the quark vertex is vector. Nevertheless symmetry breaking generates a new scalar quark vertex. In the heavy quark limit the coupling is mostly scalar. We solve the mass gap equation and find that this potential produces spontaneous chiral symmetry breaking for light quarks. The quantitative results of this model are encouraging.
2305.03905
Teruyuki Kitabayashi
Teruyuki Kitabayashi
Generalized hybrid natural inflation
6 pages, 3 figures. Accepted for publication in Physical Review D
Phys. Rev. D 108, 043514 (2023)
10.1103/PhysRevD.108.043514
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Although the hybrid natural inflation is a successful inflation model, the symmetry breaking scale in the model should be large for a negative value of the running of the scalar spectral index. This study proposed a generalized hybrid natural inflation model that can realize a low-scale inflation with a negative value of the running of the scalar spectral index.
[ { "created": "Sat, 6 May 2023 02:48:42 GMT", "version": "v1" }, { "created": "Thu, 27 Jul 2023 23:33:37 GMT", "version": "v2" } ]
2024-07-08
[ [ "Kitabayashi", "Teruyuki", "" ] ]
Although the hybrid natural inflation is a successful inflation model, the symmetry breaking scale in the model should be large for a negative value of the running of the scalar spectral index. This study proposed a generalized hybrid natural inflation model that can realize a low-scale inflation with a negative value of the running of the scalar spectral index.
hep-ph/9911221
Bjoern Poetter
B. P\"otter
JetViP 2.1: the hbook version
16 pages, LaTeX, 3 eps figures
Comput.Phys.Commun.133:105-118,2000
10.1016/S0010-4655(00)00158-2
MPI-PhT 99-054
hep-ph
null
We present an update of the JetViP 1.1 program for performing fixed NLO calculations in jet production including direct and resolved components in a continuous range of photon virtuality Q^2. The new version allows to access the full event record on the parton level. The program is set up such that hbook can be used to fill histograms. The phase space generator has been optimized and the azimuthal dependence of the cross sections is taken into account in LO. We comment on recent comparisons between various NLO programs for jet production at HERA. We demonstrate that the \Sum E_T cut for dijet cross sections is not infrared safe.
[ { "created": "Wed, 3 Nov 1999 15:59:59 GMT", "version": "v1" } ]
2014-11-17
[ [ "Pötter", "B.", "" ] ]
We present an update of the JetViP 1.1 program for performing fixed NLO calculations in jet production including direct and resolved components in a continuous range of photon virtuality Q^2. The new version allows to access the full event record on the parton level. The program is set up such that hbook can be used to fill histograms. The phase space generator has been optimized and the azimuthal dependence of the cross sections is taken into account in LO. We comment on recent comparisons between various NLO programs for jet production at HERA. We demonstrate that the \Sum E_T cut for dijet cross sections is not infrared safe.
1602.07027
Na Wang doctoral candidate
Na Wang
Charmless $B_{c}$ $\to$ $PP$, $PV$ decays in the QCD factorization approach
25 pages, revtex4
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The charmless $B_{c}$ $\to$ $PP$, $PV$~(where $P$ and $V$ denote the light pseudoscalar and vector mesons, respectively) decays can occur only via the weak annihilation diagrams within the Standard Model and provide, therefore, an ideal place to probe the strength of annihilation contribution in hadronic $B_{u,d,s}$ decays. In this paper, we study these kinds of decays in the framework of QCD factorization, by adopting two different schemes: scheme I is similar to the method usually adopted in the QCD factorization approach, while scheme II is based on the infrared behavior of gluon propagator and running coupling. For comparison, in our calculation, we adopt three kinds of wave functions for $B_{c}$ meson. It is found that: (a) The predicted branching ratios in scheme I are, however, quite small and are almost impossible to be measured at the LHCb experiment. (b) In scheme II, by assigning a dynamical gluon mass to the gluon propagator, we can avoid enhancements of the contribution from soft endpoint region. The strength of annihilation contributions predicted in scheme II is enhanced compared to that obtained in scheme I. However, the predicted branching ratios are still smaller than the corresponding ones obtained in the perturbative QCD approach. The large discrepancies among these theoretical predictions indicate that more detailed studies of these decays are urgently needed and will be tested by the future measurements performed at the LHCb experiment.
[ { "created": "Tue, 23 Feb 2016 03:58:22 GMT", "version": "v1" } ]
2016-02-24
[ [ "Wang", "Na", "" ] ]
The charmless $B_{c}$ $\to$ $PP$, $PV$~(where $P$ and $V$ denote the light pseudoscalar and vector mesons, respectively) decays can occur only via the weak annihilation diagrams within the Standard Model and provide, therefore, an ideal place to probe the strength of annihilation contribution in hadronic $B_{u,d,s}$ decays. In this paper, we study these kinds of decays in the framework of QCD factorization, by adopting two different schemes: scheme I is similar to the method usually adopted in the QCD factorization approach, while scheme II is based on the infrared behavior of gluon propagator and running coupling. For comparison, in our calculation, we adopt three kinds of wave functions for $B_{c}$ meson. It is found that: (a) The predicted branching ratios in scheme I are, however, quite small and are almost impossible to be measured at the LHCb experiment. (b) In scheme II, by assigning a dynamical gluon mass to the gluon propagator, we can avoid enhancements of the contribution from soft endpoint region. The strength of annihilation contributions predicted in scheme II is enhanced compared to that obtained in scheme I. However, the predicted branching ratios are still smaller than the corresponding ones obtained in the perturbative QCD approach. The large discrepancies among these theoretical predictions indicate that more detailed studies of these decays are urgently needed and will be tested by the future measurements performed at the LHCb experiment.
1307.7520
Chong Sheng Li
Yan Wang, Chong Sheng Li, Ze Long Liu, Ding Yu Shao and Hai Tao Li
Transverse-Momentum Resummation for Gauge Boson Pair Production at the Hadron Collider
22 pages, 6 figures, re-version
Phys. Rev. D 88, 114017 (2013)
10.1103/PhysRevD.88.114017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the transverse-momentum resummation for $W^{+}W^{-}$, $ZZ$, and $W^{\pm}Z$ pair productions at the next-to-next-to-leading logarithmic accuracy using soft-collinear effective theory for $\sqrt{S}=8 \text{TeV}$ and $\sqrt{S}=14 \text{TeV}$ at the LHC, respectively. Especially, this is the first calculation of $W^{\pm}Z$ transverse-momentum resummation. We also include the non-perturbative effects and discussions on the PDF uncertainties. Comparing with the next-to-leading logarithmic results, the next-to-next-to-leading logarithmic resummation can reduce the dependence of the transverse-momentum distribution on the factorization scales significantly. Finally, we find that our numerical results are consistent with data measured by CMS collaboration for the $ZZ$ production, which have been only reported by the LHC experiments for the unfolded transverse-momentum distribution of the gauge boson pair production so far, within theoretical and experimental uncertainties.
[ { "created": "Mon, 29 Jul 2013 09:53:44 GMT", "version": "v1" }, { "created": "Wed, 31 Jul 2013 13:54:37 GMT", "version": "v2" } ]
2013-12-16
[ [ "Wang", "Yan", "" ], [ "Li", "Chong Sheng", "" ], [ "Liu", "Ze Long", "" ], [ "Shao", "Ding Yu", "" ], [ "Li", "Hai Tao", "" ] ]
We perform the transverse-momentum resummation for $W^{+}W^{-}$, $ZZ$, and $W^{\pm}Z$ pair productions at the next-to-next-to-leading logarithmic accuracy using soft-collinear effective theory for $\sqrt{S}=8 \text{TeV}$ and $\sqrt{S}=14 \text{TeV}$ at the LHC, respectively. Especially, this is the first calculation of $W^{\pm}Z$ transverse-momentum resummation. We also include the non-perturbative effects and discussions on the PDF uncertainties. Comparing with the next-to-leading logarithmic results, the next-to-next-to-leading logarithmic resummation can reduce the dependence of the transverse-momentum distribution on the factorization scales significantly. Finally, we find that our numerical results are consistent with data measured by CMS collaboration for the $ZZ$ production, which have been only reported by the LHC experiments for the unfolded transverse-momentum distribution of the gauge boson pair production so far, within theoretical and experimental uncertainties.
hep-ph/0112324
Ismd31
XU Guofa (Representing BES Collaboration)
Recent Results and Current Status of BES
6 pages, 6 figures (2 in eps, 4 in tif) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China. See http://ismd31.ccnu.edu.cn/
null
null
null
hep-ph
null
The current status of BESII is reported. Some published results based on the data collected by BESI and some new preliminary results based on the BESII data are reviewed in this paper.
[ { "created": "Tue, 25 Dec 2001 09:33:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Guofa", "XU", "", "Representing BES Collaboration" ] ]
The current status of BESII is reported. Some published results based on the data collected by BESI and some new preliminary results based on the BESII data are reviewed in this paper.
hep-ph/9907220
Emilio Torrente Lujan
E. Torrente-Lujan
The decay $b\to s\gamma$ and the charged Higgs boson mass without R-Parity
Based on work made in collaboration with M. A. D\'\i az and J. W. F. Valle and presented at: ``TMR Network on Physics beyond the SM''. Trieste, February 1999.}
null
null
IFIC-99-233,FTUV-99-23
hep-ph
null
The experimental measurement of $B(b \to s\gamma)$ imposes important constraints on the charged Higgs boson mass in the MSSM. We show that by adding bilinear R--Parity violation (BRpV) in the tau sector, these bounds are relaxed. The bound on $m_{H^{\pm}}$ in the MSSM--BRpV model is $\gsim 200-250$ GeV for the the heavy squark limit. For lighter squarks, light charged Higgs bosons can be reconciled with $B(b \to s\gamma)$ only if there is also a light chargino. In the BRpV model if we impose $m_{\chi^{\pm}_1}>90$ GeV $m_{H^{\pm}} \gsim 75$ GeV, around 30 GeV down from the MSSM. In this case the charged Higgs bosons would be observable at LEP II. The relaxation of the bounds is due mainly to the fact that charged Higgs bosons mix with staus and they contribute importantly to $B(b \to s\gamma)$.
[ { "created": "Sat, 3 Jul 1999 14:52:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Torrente-Lujan", "E.", "" ] ]
The experimental measurement of $B(b \to s\gamma)$ imposes important constraints on the charged Higgs boson mass in the MSSM. We show that by adding bilinear R--Parity violation (BRpV) in the tau sector, these bounds are relaxed. The bound on $m_{H^{\pm}}$ in the MSSM--BRpV model is $\gsim 200-250$ GeV for the the heavy squark limit. For lighter squarks, light charged Higgs bosons can be reconciled with $B(b \to s\gamma)$ only if there is also a light chargino. In the BRpV model if we impose $m_{\chi^{\pm}_1}>90$ GeV $m_{H^{\pm}} \gsim 75$ GeV, around 30 GeV down from the MSSM. In this case the charged Higgs bosons would be observable at LEP II. The relaxation of the bounds is due mainly to the fact that charged Higgs bosons mix with staus and they contribute importantly to $B(b \to s\gamma)$.
hep-ph/9301293
Mike Booth
Michael Booth
The Electric Dipole Moment of the W and Electron in the Standard Model
8 pages, LaTeX, 2 figures (eps or mf) included in separate file. This paper should also be available by anonymous ftp as ftp://rainbow.uchicago.edu:/pt-preprints/wedm.ps.Z Changes: Added refence to and brief discussion of similar previous work
null
null
EFI-93-01
hep-ph
null
I show that the electric dipole moment of the W-boson vanishes to two loop order in the Standard KM model. As a consequence, the electric dipole moment of the electron vanishes to three loop order. Including QCD corrections may give a non-vanishing result; I estimate d_W \approx 8 10^-31 ecm which induces an electron EDM \approx 8 10^-41 ecm, considerably smaller found in a previous calculation.
[ { "created": "Sat, 30 Jan 1993 01:32:06 GMT", "version": "v1" }, { "created": "Thu, 4 Feb 1993 02:18:07 GMT", "version": "v2" }, { "created": "Thu, 4 Feb 1993 02:09:05 GMT", "version": "v3" } ]
2009-09-25
[ [ "Booth", "Michael", "" ] ]
I show that the electric dipole moment of the W-boson vanishes to two loop order in the Standard KM model. As a consequence, the electric dipole moment of the electron vanishes to three loop order. Including QCD corrections may give a non-vanishing result; I estimate d_W \approx 8 10^-31 ecm which induces an electron EDM \approx 8 10^-41 ecm, considerably smaller found in a previous calculation.
hep-ph/0404073
Jonathan Rosner
Cheng-Wei Chiang, Michael Gronau, Jonathan L. Rosner, and Denis A. Suprun
Charmless $B \to PP$ decays using flavor SU(3) symmetry
26 pages, 1 figure. To be submitted to Phys. Rev. D. Reference updated
Phys.Rev.D70:034020,2004
10.1103/PhysRevD.70.034020
MADPH-04-1372; CLNS-04-1869
hep-ph
null
The decays of $B$ mesons to a pair of charmless pseudoscalar ($P$) mesons are analyzed within a framework of flavor SU(3). Symmetry breaking is taken into account in tree ($T$) amplitudes through ratios of decay constants; exact SU(3) is assumed elsewhere. Acceptable fits to $B \to \pi \pi$ and $B \to K \pi$ branching ratios and CP asymmetries are obtained with tree, color-suppressed ($C$), penguin ($P$), and electroweak penguin ($P_{EW}$) amplitudes. Crucial additional terms for describing processes involving $\eta$ and $\eta'$ include a large flavor-singlet penguin amplitude ($S$) as proposed earlier and a penguin amplitude $P_{tu}$ associated with intermediate $t$ and $u$ quarks. For the $B^+ \to \pi^+ \eta'$ mode a term $S_{tu}$ associated with intermediate $t$ and $u$ quarks also may be needed. Values of the weak phase $\gamma$ are obtained consistent with an earlier analysis of $B \to VP$ decays, where $V$ denotes a vector meson, and with other analyses of CKM parameters.
[ { "created": "Wed, 7 Apr 2004 17:35:22 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2004 20:12:22 GMT", "version": "v2" }, { "created": "Fri, 9 Apr 2004 15:07:54 GMT", "version": "v3" } ]
2014-11-17
[ [ "Chiang", "Cheng-Wei", "" ], [ "Gronau", "Michael", "" ], [ "Rosner", "Jonathan L.", "" ], [ "Suprun", "Denis A.", "" ] ]
The decays of $B$ mesons to a pair of charmless pseudoscalar ($P$) mesons are analyzed within a framework of flavor SU(3). Symmetry breaking is taken into account in tree ($T$) amplitudes through ratios of decay constants; exact SU(3) is assumed elsewhere. Acceptable fits to $B \to \pi \pi$ and $B \to K \pi$ branching ratios and CP asymmetries are obtained with tree, color-suppressed ($C$), penguin ($P$), and electroweak penguin ($P_{EW}$) amplitudes. Crucial additional terms for describing processes involving $\eta$ and $\eta'$ include a large flavor-singlet penguin amplitude ($S$) as proposed earlier and a penguin amplitude $P_{tu}$ associated with intermediate $t$ and $u$ quarks. For the $B^+ \to \pi^+ \eta'$ mode a term $S_{tu}$ associated with intermediate $t$ and $u$ quarks also may be needed. Values of the weak phase $\gamma$ are obtained consistent with an earlier analysis of $B \to VP$ decays, where $V$ denotes a vector meson, and with other analyses of CKM parameters.
hep-ph/9911251
Nobuchika Okada
Noriaki Kitazawa, Nobuhito Maru and Nobuchika Okada
Dynamical Supersymmetry Breaking with Gauged U(1)_R Symmetry
7 pages, revised manuscript to appear in Phys. Rev. D
Phys.Rev. D62 (2000) 077701
10.1103/PhysRevD.62.077701
TMUP-HEL-9912, TIT/HEP-435, KEK-TH-659
hep-ph
null
We propose a simple model of dynamical supersymmetry breaking in the context of minimal supergravity with gauged $U(1)_R$ symmetry. The model is based on the gauge group $SU(2) \times U(1)_R$ with three matters. Since the $U(1)_R$ symmetry is gauged, the Fayet-Iliopoulos D-term appears due to the symmetry of supergravity. On the other hand, the superpotential generated dynamically by the SU(2) gauge dynamics leads to run away potential. Since the supersymmetric vacuum condition required by the D-term potential contradicts the one required by the superpotential, supersymmetry is broken. The supersymmetry breaking scale is controlled by the dynamical scale of the SU(2) gauge interaction. We can choose the parameters in our model for vanishing cosmological constant. Our model is phenomenologically viable with the gravitino mass of order 1 TeV or 10 TeV.
[ { "created": "Fri, 5 Nov 1999 11:37:52 GMT", "version": "v1" }, { "created": "Thu, 8 Jun 2000 07:31:24 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kitazawa", "Noriaki", "" ], [ "Maru", "Nobuhito", "" ], [ "Okada", "Nobuchika", "" ] ]
We propose a simple model of dynamical supersymmetry breaking in the context of minimal supergravity with gauged $U(1)_R$ symmetry. The model is based on the gauge group $SU(2) \times U(1)_R$ with three matters. Since the $U(1)_R$ symmetry is gauged, the Fayet-Iliopoulos D-term appears due to the symmetry of supergravity. On the other hand, the superpotential generated dynamically by the SU(2) gauge dynamics leads to run away potential. Since the supersymmetric vacuum condition required by the D-term potential contradicts the one required by the superpotential, supersymmetry is broken. The supersymmetry breaking scale is controlled by the dynamical scale of the SU(2) gauge interaction. We can choose the parameters in our model for vanishing cosmological constant. Our model is phenomenologically viable with the gravitino mass of order 1 TeV or 10 TeV.
hep-ph/0304174
Fuming Liu
F.M. Liu, K. Werner, J. Aichelin
Comparison of Microcanonical and Canonical Hadronization
14 pages, 7 figures
Phys.Rev. C68 (2003) 024905
10.1103/PhysRevC.68.024905
null
hep-ph
null
Average multiplicities and transverse momenta of hadrons are calculated using a microcanonical hadronization description for a cluster of given total energy and volume. As a function of the total energy, we determine the critical volume above which the microcanonical description coincides with the canonical one, and compare the results with those obtained using one of standard canonical models. We show that the critical volume depends on the energy and the mass of the hadrons. For heavy particles, volumes above $50 fm^{3}$ are needed, even more than$100 fm^{3}$ if one considers transverse momenta. Thus the prediction of heavy hadron multiplicities in pp, Kp, and $e^{+}e^{-}$ reactions requires a microcanonical approach, whereas for heavy ion reactions a canonical calculation is valid. We conclude by showing the importance of the feeding for the observed hadron multiplicities.
[ { "created": "Thu, 17 Apr 2003 13:14:19 GMT", "version": "v1" } ]
2009-11-10
[ [ "Liu", "F. M.", "" ], [ "Werner", "K.", "" ], [ "Aichelin", "J.", "" ] ]
Average multiplicities and transverse momenta of hadrons are calculated using a microcanonical hadronization description for a cluster of given total energy and volume. As a function of the total energy, we determine the critical volume above which the microcanonical description coincides with the canonical one, and compare the results with those obtained using one of standard canonical models. We show that the critical volume depends on the energy and the mass of the hadrons. For heavy particles, volumes above $50 fm^{3}$ are needed, even more than$100 fm^{3}$ if one considers transverse momenta. Thus the prediction of heavy hadron multiplicities in pp, Kp, and $e^{+}e^{-}$ reactions requires a microcanonical approach, whereas for heavy ion reactions a canonical calculation is valid. We conclude by showing the importance of the feeding for the observed hadron multiplicities.
hep-ph/9509413
Salman Habib
Salman Habib, Yuval Kluger, Emil Mottola, and Juan Pablo Paz
Dissipation and Decoherence in Mean Field Theory
9 pages, LaTeX, figures included
Phys.Rev.Lett. 76 (1996) 4660-4663
10.1103/PhysRevLett.76.4660
LA-UR-95-3393, LBL-37786
hep-ph cond-mat gr-qc hep-th quant-ph
null
The time evolution of a closed system of mean fields and fluctuations is Hamiltonian, with the canonical variables parameterizing the general time-dependent Gaussian density matrix of the system. Yet, the evolution manifests both quantum decoherence and apparent irreversibility of energy flow from the coherent mean fields to fluctuating quantum modes. Using scalar QED as an example we show how this collisionless damping and decoherence may be understood as the result of {\em dephasing} of the rapidly varying fluctuations and particle production in the time varying mean field.
[ { "created": "Thu, 28 Sep 1995 23:15:07 GMT", "version": "v1" } ]
2009-10-28
[ [ "Habib", "Salman", "" ], [ "Kluger", "Yuval", "" ], [ "Mottola", "Emil", "" ], [ "Paz", "Juan Pablo", "" ] ]
The time evolution of a closed system of mean fields and fluctuations is Hamiltonian, with the canonical variables parameterizing the general time-dependent Gaussian density matrix of the system. Yet, the evolution manifests both quantum decoherence and apparent irreversibility of energy flow from the coherent mean fields to fluctuating quantum modes. Using scalar QED as an example we show how this collisionless damping and decoherence may be understood as the result of {\em dephasing} of the rapidly varying fluctuations and particle production in the time varying mean field.
hep-ph/0407265
Nikolaos Mavromatos
Jean Alexandre (King's Coll. Lon.), K. Farakos (NTUA) and N.E. Mavromatos (King's Coll. Lon.)
Anomalous magnetic moment in parity-conserving QED3
27 pages LATEX, three eps figures incorporated
New J.Phys. 7 (2005) 48
10.1088/1367-2630/7/1/048
null
hep-ph cond-mat.str-el hep-th
null
In this article we derive the anomalous magnetic moment of fermions in (2+1)-dimensional parity-conserving QED3, in the presence of an externally applied constant magnetic field. We use a spectral representation of the photon propagator to avoid infrared divergences. We also discuss the scaling with the magnetic field intensity in the case of strong external fields, where there is dynamical mass generation for fermions induced by the magnetic field itself (magnetic catalysis). The results of this paper may be of relevance to the physics of high-temperature superconductors.
[ { "created": "Thu, 22 Jul 2004 16:32:43 GMT", "version": "v1" } ]
2009-11-10
[ [ "Alexandre", "Jean", "", "King's Coll. Lon." ], [ "Farakos", "K.", "", "NTUA" ], [ "Mavromatos", "N. E.", "", "King's Coll. Lon." ] ]
In this article we derive the anomalous magnetic moment of fermions in (2+1)-dimensional parity-conserving QED3, in the presence of an externally applied constant magnetic field. We use a spectral representation of the photon propagator to avoid infrared divergences. We also discuss the scaling with the magnetic field intensity in the case of strong external fields, where there is dynamical mass generation for fermions induced by the magnetic field itself (magnetic catalysis). The results of this paper may be of relevance to the physics of high-temperature superconductors.
2004.04172
Felix Kling
Felix Kling, Shufang Su and Wei Su
2HDM Neutral Scalars under the LHC
Version published in JHEP
JHEP 06 (2020) 163
10.1007/JHEP06(2020)163
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two Higgs Doublet Models (2HDM) provide a simple framework for new physics models with an extended Higgs sector. The current LHC results, including both direct searches for additional non-Standard Model (SM) Higgs bosons, as well as precision measurements of the SM-like Higgs couplings, already provide strong constraints on the 2HDM parameter spaces. In this paper, we examine those constraints for the neutral scalars in the Type-I and Type-II 2HDM. In addition to the direct search channels with SM final states: $H/A \to f\bar f, VV, Vh, hh$, we study in particular the exotic decay channels of $H/A \to AZ/HZ$ once there is a mass hierarchy between the non-SM Higgses. We found that $H/A \to AZ/HZ$ channel has unique sensitivity to the alignment limit region which remains unconstrained by conventional searches and Higgs precision measurements. This mode also extends the reach at intermediate $\tan\beta$ for heavy $m_A$ that are not covered by the other direct searches.
[ { "created": "Wed, 8 Apr 2020 18:00:05 GMT", "version": "v1" }, { "created": "Thu, 23 Jul 2020 12:25:21 GMT", "version": "v2" }, { "created": "Wed, 2 Dec 2020 02:47:40 GMT", "version": "v3" } ]
2020-12-03
[ [ "Kling", "Felix", "" ], [ "Su", "Shufang", "" ], [ "Su", "Wei", "" ] ]
Two Higgs Doublet Models (2HDM) provide a simple framework for new physics models with an extended Higgs sector. The current LHC results, including both direct searches for additional non-Standard Model (SM) Higgs bosons, as well as precision measurements of the SM-like Higgs couplings, already provide strong constraints on the 2HDM parameter spaces. In this paper, we examine those constraints for the neutral scalars in the Type-I and Type-II 2HDM. In addition to the direct search channels with SM final states: $H/A \to f\bar f, VV, Vh, hh$, we study in particular the exotic decay channels of $H/A \to AZ/HZ$ once there is a mass hierarchy between the non-SM Higgses. We found that $H/A \to AZ/HZ$ channel has unique sensitivity to the alignment limit region which remains unconstrained by conventional searches and Higgs precision measurements. This mode also extends the reach at intermediate $\tan\beta$ for heavy $m_A$ that are not covered by the other direct searches.
1812.11925
Laura Reina
Steve Honeywell, Seth Quackenbush, Laura Reina, and Christian Reuschle
NLOX, a one-loop provider for Standard Model processes
39 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
NLOX is a computer program for calculations in high-energy particle physics. It provides fully renormalized scattering matrix elements in the Standard Model of particle physics, up to one-loop accuracy for all possible coupling-power combinations in the strong and electroweak couplings, and for processes with up to six external particles.
[ { "created": "Mon, 31 Dec 2018 18:08:23 GMT", "version": "v1" } ]
2019-01-01
[ [ "Honeywell", "Steve", "" ], [ "Quackenbush", "Seth", "" ], [ "Reina", "Laura", "" ], [ "Reuschle", "Christian", "" ] ]
NLOX is a computer program for calculations in high-energy particle physics. It provides fully renormalized scattering matrix elements in the Standard Model of particle physics, up to one-loop accuracy for all possible coupling-power combinations in the strong and electroweak couplings, and for processes with up to six external particles.
1509.06938
Florian Bernlochner
Florian U. Bernlochner
The B -> pi tau nu decay in the context of the 2HDM type II
6 pages
Phys. Rev. D 92, 115019 (2015)
10.1103/PhysRevD.92.115019
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this manuscript the B -> pi tau nu decay is investigated in the context of the 2HDM type II extension of the SM. In particular, predictions for the ratio of semileptonic branching fractions from l = tau and l = electron, muon are produced and an exclusion based on the MSSM parameters tan beta and mH+ from a preliminary Belle measurement are reported. An alternative variable to the ratio of branching fractions that could offer increased sensitivity is discussed that could result in increased sensitivity to rule out contributions from additional scalar mediators.
[ { "created": "Wed, 23 Sep 2015 12:14:17 GMT", "version": "v1" }, { "created": "Tue, 29 Sep 2015 12:59:15 GMT", "version": "v2" }, { "created": "Thu, 3 Dec 2015 16:56:16 GMT", "version": "v3" } ]
2015-12-30
[ [ "Bernlochner", "Florian U.", "" ] ]
In this manuscript the B -> pi tau nu decay is investigated in the context of the 2HDM type II extension of the SM. In particular, predictions for the ratio of semileptonic branching fractions from l = tau and l = electron, muon are produced and an exclusion based on the MSSM parameters tan beta and mH+ from a preliminary Belle measurement are reported. An alternative variable to the ratio of branching fractions that could offer increased sensitivity is discussed that could result in increased sensitivity to rule out contributions from additional scalar mediators.
2305.00392
ChuanLe Sun
Xu-Run Huang, Chuan-Le Sun, Lie-Wen Chen, Jun Gao
Bayesian Inference of Supernova Neutrino Spectra with Multiple Detectors
25 pages, 7 figures, 4 tables, published version
JCAP09(2023)040
null
null
hep-ph astro-ph.HE nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We implement the Bayesian inference to retrieve energy spectra of all neutrinos from a galactic core-collapse supernova (CCSN). To achieve high statistics and full sensitivity to all flavours of neutrinos, we adopt a combination of several reaction channels from different large-scale neutrino observatories, namely inverse beta decay on proton and elastic scattering on electron from Hyper-Kamiokande (Hyper-K), charged current absorption on Argon from Deep Underground Neutrino Experiment (DUNE) and coherent elastic scattering on Lead from RES-NOVA. Assuming no neutrino oscillation or specific oscillation models, we obtain mock data for each channel through Poisson processes with the predictions, for a typical source distance of 10 kpc in our Galaxy, and then evaluate the probability distributions for all spectral parameters of theoretical neutrino spectrum model with Bayes' theorem. Although the results for either the electron-neutrinos or electron-antineutrinos reserve relatively large uncertainties (according to the neutrino mass hierarchy), a precision of a few percent (i.e., $\pm 1 \% \sim \pm 4 \%$ at a credible interval of $2 \sigma$) is achieved for primary spectral parameters (e.g., mean energy and total emitted energy) of other neutrino species. Moreover, the correlation coefficients between different parameters are computed as well and interesting patterns are found. Especially, the mixing-induced correlations are sensitive to the neutrino mass hierarchy, which potentially makes it a brand new probe to determine the neutrino mass hierarchy in the detection of galactic supernova neutrinos. Finally, we discuss the origin of such correlation patterns and perspectives for further improvement on our results.
[ { "created": "Sun, 30 Apr 2023 05:26:21 GMT", "version": "v1" }, { "created": "Sun, 24 Sep 2023 05:49:32 GMT", "version": "v2" } ]
2023-09-26
[ [ "Huang", "Xu-Run", "" ], [ "Sun", "Chuan-Le", "" ], [ "Chen", "Lie-Wen", "" ], [ "Gao", "Jun", "" ] ]
We implement the Bayesian inference to retrieve energy spectra of all neutrinos from a galactic core-collapse supernova (CCSN). To achieve high statistics and full sensitivity to all flavours of neutrinos, we adopt a combination of several reaction channels from different large-scale neutrino observatories, namely inverse beta decay on proton and elastic scattering on electron from Hyper-Kamiokande (Hyper-K), charged current absorption on Argon from Deep Underground Neutrino Experiment (DUNE) and coherent elastic scattering on Lead from RES-NOVA. Assuming no neutrino oscillation or specific oscillation models, we obtain mock data for each channel through Poisson processes with the predictions, for a typical source distance of 10 kpc in our Galaxy, and then evaluate the probability distributions for all spectral parameters of theoretical neutrino spectrum model with Bayes' theorem. Although the results for either the electron-neutrinos or electron-antineutrinos reserve relatively large uncertainties (according to the neutrino mass hierarchy), a precision of a few percent (i.e., $\pm 1 \% \sim \pm 4 \%$ at a credible interval of $2 \sigma$) is achieved for primary spectral parameters (e.g., mean energy and total emitted energy) of other neutrino species. Moreover, the correlation coefficients between different parameters are computed as well and interesting patterns are found. Especially, the mixing-induced correlations are sensitive to the neutrino mass hierarchy, which potentially makes it a brand new probe to determine the neutrino mass hierarchy in the detection of galactic supernova neutrinos. Finally, we discuss the origin of such correlation patterns and perspectives for further improvement on our results.
1512.04921
Andrei Angelescu
Andrei Angelescu, Abdelhak Djouadi and Gr\'egory Moreau
Scenarii for interpretations of the LHC diphoton excess: two Higgs doublets and vector-like quarks and leptons
13 pages, 2 figures. v3: Discussion in section 3 extended and inconsistency in the pseudoscalar coupling corrected; conclusions unchanged
null
10.1016/j.physletb.2016.02.064
LPT-Orsay-15-99
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An evidence for a diphoton resonance at a mass of 750 GeV has been observed in the data collected at the LHC run at a center of mass energy of 13 TeV. We explore several interpretations of this signal in terms of Higgs-like resonances in a two-Higgs doublet model and its supersymmetric incarnation, in which the heavier CP-even and CP-odd states present in the model are produced in gluon fusion and decay into two photons through top quark loops. We show that one cannot accommodate the observed signal in the minimal versions of these models and that an additional particle content is necessary. We then consider the possibility that vector-like quarks or leptons strongly enhance the heavy Higgs couplings to photons and eventually gluons, without altering those of the already observed 125 GeV state.
[ { "created": "Tue, 15 Dec 2015 20:32:58 GMT", "version": "v1" }, { "created": "Wed, 23 Dec 2015 20:57:31 GMT", "version": "v2" }, { "created": "Tue, 19 Jan 2016 20:52:08 GMT", "version": "v3" } ]
2016-03-09
[ [ "Angelescu", "Andrei", "" ], [ "Djouadi", "Abdelhak", "" ], [ "Moreau", "Grégory", "" ] ]
An evidence for a diphoton resonance at a mass of 750 GeV has been observed in the data collected at the LHC run at a center of mass energy of 13 TeV. We explore several interpretations of this signal in terms of Higgs-like resonances in a two-Higgs doublet model and its supersymmetric incarnation, in which the heavier CP-even and CP-odd states present in the model are produced in gluon fusion and decay into two photons through top quark loops. We show that one cannot accommodate the observed signal in the minimal versions of these models and that an additional particle content is necessary. We then consider the possibility that vector-like quarks or leptons strongly enhance the heavy Higgs couplings to photons and eventually gluons, without altering those of the already observed 125 GeV state.
hep-ph/0506147
Bindu Anubha Bambah
C.Mukku, Bindu A. Bambah, K.V.S. Shiv Chaitanya
Pions emerging from an Arbitrarily Disoriented Chiral Condensate
5 pages, 3 figure. talk given by C. mukku at ICPAPGQP 2005. kolkatta .inia. To be Published in a special issue of Journal of Physics 'G'
null
null
null
hep-ph
null
We model the evolution of the disoriented chiral condensate formed through both a sudden quench and through a phase transition with a metastable state of arbitrary disorientation . We show that the total multiplicity distributions of charged and neutral pions functions are dramatic characteristic signals for the DCC and are related directly to the way in which the DCC forms.
[ { "created": "Wed, 15 Jun 2005 16:20:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mukku", "C.", "" ], [ "Bambah", "Bindu A.", "" ], [ "Chaitanya", "K. V. S. Shiv", "" ] ]
We model the evolution of the disoriented chiral condensate formed through both a sudden quench and through a phase transition with a metastable state of arbitrary disorientation . We show that the total multiplicity distributions of charged and neutral pions functions are dramatic characteristic signals for the DCC and are related directly to the way in which the DCC forms.
2108.00195
Elisa Maria Todarello
Ariel Arza, Elisa Todarello
The axion dark matter echo: a detailed analysis
Matches published version
null
10.1103/PhysRevD.105.023023
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/publicdomain/zero/1.0/
It was recently shown that a powerful beam of radio/microwave radiation sent out to space can produce detectable back-scattering via the stimulated decay of ambient axion dark matter. This echo is a faint and narrow signal centered at an angular frequency close to half the axion mass. In this article, we provide a detailed analytical and numerical analysis of this signal, considering the effects of the axion velocity distribution as well as the outgoing beam shape. In agreement with the original proposal, we find that the divergence of the outgoing beam does not affect the echo signal, which is only constrained by the axion velocity distribution. Moreover, our findings are relevant for the optimization of the experimental parameters in order to attain maximal signal to noise or minimal energy consumption.
[ { "created": "Sat, 31 Jul 2021 09:42:17 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2022 09:56:25 GMT", "version": "v2" } ]
2022-02-24
[ [ "Arza", "Ariel", "" ], [ "Todarello", "Elisa", "" ] ]
It was recently shown that a powerful beam of radio/microwave radiation sent out to space can produce detectable back-scattering via the stimulated decay of ambient axion dark matter. This echo is a faint and narrow signal centered at an angular frequency close to half the axion mass. In this article, we provide a detailed analytical and numerical analysis of this signal, considering the effects of the axion velocity distribution as well as the outgoing beam shape. In agreement with the original proposal, we find that the divergence of the outgoing beam does not affect the echo signal, which is only constrained by the axion velocity distribution. Moreover, our findings are relevant for the optimization of the experimental parameters in order to attain maximal signal to noise or minimal energy consumption.
2303.04818
Herschel A. Chawdhry
Herschel A. Chawdhry and Mathieu Pellen
Quantum simulation of colour in perturbative quantum chromodynamics
20 pages, 11 figures. v2: published version
SciPost Phys. 15, 205 (2023)
10.21468/SciPostPhys.15.5.205
FR-PHENO-2023-02, OUTP-23-02P
hep-ph hep-th quant-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
Quantum computers are expected to give major speed-ups for the simulation of quantum systems. In this work, we present quantum gates that simulate the colour part of the interactions of quarks and gluons in perturbative quantum chromodynamics (QCD). As a first application, we implement these circuits on a simulated noiseless quantum computer and use them to calculate colour factors for various examples of Feynman diagrams. This work constitutes a first key step towards a quantum simulation of generic scattering processes in perturbative QCD.
[ { "created": "Wed, 8 Mar 2023 19:00:01 GMT", "version": "v1" }, { "created": "Fri, 1 Dec 2023 04:25:54 GMT", "version": "v2" } ]
2023-12-04
[ [ "Chawdhry", "Herschel A.", "" ], [ "Pellen", "Mathieu", "" ] ]
Quantum computers are expected to give major speed-ups for the simulation of quantum systems. In this work, we present quantum gates that simulate the colour part of the interactions of quarks and gluons in perturbative quantum chromodynamics (QCD). As a first application, we implement these circuits on a simulated noiseless quantum computer and use them to calculate colour factors for various examples of Feynman diagrams. This work constitutes a first key step towards a quantum simulation of generic scattering processes in perturbative QCD.
1205.2054
Myeonghun Park
Lisa Edelh\"auser, Konstantin T. Matchev, Myeonghun Park
Spin effects in the antler event topology at hadron colliders
43 pages, 14 figures, Preprint typeset in JHEP style
null
10.1007/JHEP11(2012)006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate spin correlation effects in the "antler" event topology pp-> A-> B1, B2 -> l^{-}, C1, l^{+}, C2 at the LHC. We study the shapes of several kinematic variables, including the relative pseudorapidity, relative azimuthal angle and the energies of the two leptons, as well as several mass variables M_{ll}, Meff, \sqrt{s}_{min}, MT2, MCT and MCTx. We focus on the two kinematic extremes of \sqrt{s} - threshold and infinity - and derive analytical expressions for the differential distributions of several variables, most notably the cos{\theta_{ll}}^* variable proposed by Barr in hep-ph/0511115. For all possible spin assignments of particles A, B and C, we derive the cos{\theta_{ll}}^* differential distribution at threshold, including the effects of spin correlations. Our analytical results help identify the problematic cases for spin discrimination.
[ { "created": "Wed, 9 May 2012 18:13:01 GMT", "version": "v1" } ]
2015-06-05
[ [ "Edelhäuser", "Lisa", "" ], [ "Matchev", "Konstantin T.", "" ], [ "Park", "Myeonghun", "" ] ]
We investigate spin correlation effects in the "antler" event topology pp-> A-> B1, B2 -> l^{-}, C1, l^{+}, C2 at the LHC. We study the shapes of several kinematic variables, including the relative pseudorapidity, relative azimuthal angle and the energies of the two leptons, as well as several mass variables M_{ll}, Meff, \sqrt{s}_{min}, MT2, MCT and MCTx. We focus on the two kinematic extremes of \sqrt{s} - threshold and infinity - and derive analytical expressions for the differential distributions of several variables, most notably the cos{\theta_{ll}}^* variable proposed by Barr in hep-ph/0511115. For all possible spin assignments of particles A, B and C, we derive the cos{\theta_{ll}}^* differential distribution at threshold, including the effects of spin correlations. Our analytical results help identify the problematic cases for spin discrimination.
hep-ph/9405359
null
M.Baillargeon, G. Belanger and F. Boudjema
Electroweak Physics Issues at a High Energy Photon Collider
75 pages, 25 encaps. figures, ENSLAPP-A-473/94 LaTeX. no changes but now full .ps file available via anonymous ftp at LPSVSH.LPS.UMONTREAL.CA as [ANONYMOUS.THEORIE.BELANGER]PARISGG.PS (1 Mb compressed, 2 Mb, uncompressed)
null
null
null
hep-ph
null
The main attractions of studying the bosonic sector of the electroweak standard model and its extensions at a future high energy photon collider are reviewed. A presentation of the laser scheme for obtaining such a collider is given where we emphasize the importance of polarised \gag spectra. The need for {\em measuring} the differential luminosities is stressed. We show that, in a large variety of processes, the yield of weak vector bosons is much higher than at the \epm mode but unfortunately, the cross sections are dominated by the transverse modes. Investigation of the physics related to the symmetry breaking sector both in $W$ and $Z$ pair production is given and contrasted with what we expect to obtain in the \epm mode and at the LHC. We reassess the issue of whether an intermediate-mass Higgs can be observed as a resonance when we have a broad spectrum that allows the simultaneous study of a host of electroweak phenomena. This investigation includes the important background of the so-called ``resolved" photon. We analyse the important issues of the mass resolution, the $b$ tagging efficiencies, and the polarisation of the beams at two typical \epm energies: 300GeV and 500GeV. New efficient cuts are found to suppress the background. The importance of $WWH$ production at $\sim$1TeV is emphasized and contrasted with other Higgs production mechanisms at both \epm and $e\gamma$. Finally, we examine the interesting problem of the longitudinal $W$ ($W_L$) content of the photon. A new set of polarised structure functions for the $W_L$ inside the photon is proposed. We test the validity of the ensuing effective $W$ approximation in the \ggwwht process.
[ { "created": "Mon, 23 May 1994 18:57:44 GMT", "version": "v1" }, { "created": "Tue, 24 May 1994 10:43:25 GMT", "version": "v2" } ]
2008-02-03
[ [ "Baillargeon", "M.", "" ], [ "Belanger", "G.", "" ], [ "Boudjema", "F.", "" ] ]
The main attractions of studying the bosonic sector of the electroweak standard model and its extensions at a future high energy photon collider are reviewed. A presentation of the laser scheme for obtaining such a collider is given where we emphasize the importance of polarised \gag spectra. The need for {\em measuring} the differential luminosities is stressed. We show that, in a large variety of processes, the yield of weak vector bosons is much higher than at the \epm mode but unfortunately, the cross sections are dominated by the transverse modes. Investigation of the physics related to the symmetry breaking sector both in $W$ and $Z$ pair production is given and contrasted with what we expect to obtain in the \epm mode and at the LHC. We reassess the issue of whether an intermediate-mass Higgs can be observed as a resonance when we have a broad spectrum that allows the simultaneous study of a host of electroweak phenomena. This investigation includes the important background of the so-called ``resolved" photon. We analyse the important issues of the mass resolution, the $b$ tagging efficiencies, and the polarisation of the beams at two typical \epm energies: 300GeV and 500GeV. New efficient cuts are found to suppress the background. The importance of $WWH$ production at $\sim$1TeV is emphasized and contrasted with other Higgs production mechanisms at both \epm and $e\gamma$. Finally, we examine the interesting problem of the longitudinal $W$ ($W_L$) content of the photon. A new set of polarised structure functions for the $W_L$ inside the photon is proposed. We test the validity of the ensuing effective $W$ approximation in the \ggwwht process.
hep-ph/9709396
Zoltan Ligeti
Zoltan Ligeti
Semileptonic B decays to excited charm mesons
9 pages, Talk given at Seventh International Symposium On Heavy Flavor Physics, July 7-11, 1997, Santa Barbara
null
null
CALT-68-2135, UCSD/PTH 97-27
hep-ph
null
Exclusive semileptonic B decays to the lightest excited charmed mesons are investigated at order $\Lambda_{QCD}/m_Q$ in the heavy quark effective theory. At zero recoil, $\Lambda_{QCD}/m_Q$ corrections to the matrix elements of the weak currents can be written in terms of the leading Isgur-Wise functions for the corresponding transition and meson mass splittings. The differential decay rates are predicted, including $\Lambda_{QCD}/m_Q$ corrections with some model dependence away from zero recoil. Applications to B decay sum rules and factorization are presented.
[ { "created": "Thu, 18 Sep 1997 16:30:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ligeti", "Zoltan", "" ] ]
Exclusive semileptonic B decays to the lightest excited charmed mesons are investigated at order $\Lambda_{QCD}/m_Q$ in the heavy quark effective theory. At zero recoil, $\Lambda_{QCD}/m_Q$ corrections to the matrix elements of the weak currents can be written in terms of the leading Isgur-Wise functions for the corresponding transition and meson mass splittings. The differential decay rates are predicted, including $\Lambda_{QCD}/m_Q$ corrections with some model dependence away from zero recoil. Applications to B decay sum rules and factorization are presented.
1907.06693
Hasan Serce
Howard Baer, Vernon Barger, Hasan Serce
Lepton flavor violation from SUSY with non-universal scalars
18 pages, 9 figures
Phys. Rev. Research 1, 033022 (2019)
10.1103/PhysRevResearch.1.033022
OU-HEP-190715
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Right-handed neutrinos in supersymmetric models can act as the source of lepton flavor violation (LFV). We present experimental implications of lepton flavor-violating processes within a supersymmetric type-I seesaw framework in the three-extra-parameter non-universal Higgs model (NUHM3) for large (PMNS-like) and small (CKM-like) Yukawa mixing scenarios. We highlight LFV predictions for the natural (low $\Delta_{\rm EW}$) portion of parameter space. Our numerical analysis includes full 2-loop renormalization group running effects for the three neutrino masses and mass matrices. We show the projected discovery reach of various LFV experiments ($\textit{i.e.}$ Mu2e, Mu3e, MEG-II, Belle-II), and specify regions that have already been excluded by the LHC searches. Our results depend strongly on whether one has a normal sneutrino hierarchy (NSH) or an inverted sneutrino hierarchy (ISH). Natural SUSY with a NSH is already excluded by MEG-2013 results while large portions of ISH have been or will soon be tested. However, LFV processes from natural SUSY with small Yukawa mixing and an ISH seem below any projected sensitivities. A substantial amount of the remaining parameter space of models with large PMNS-like sneutrino mixing will be probed by Mu2e and MEG-II experiments whereas small, CKM-like Yukawa mixing predicts LFV decays which can hide from LFV experiments.
[ { "created": "Mon, 15 Jul 2019 18:55:01 GMT", "version": "v1" } ]
2019-10-23
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Serce", "Hasan", "" ] ]
Right-handed neutrinos in supersymmetric models can act as the source of lepton flavor violation (LFV). We present experimental implications of lepton flavor-violating processes within a supersymmetric type-I seesaw framework in the three-extra-parameter non-universal Higgs model (NUHM3) for large (PMNS-like) and small (CKM-like) Yukawa mixing scenarios. We highlight LFV predictions for the natural (low $\Delta_{\rm EW}$) portion of parameter space. Our numerical analysis includes full 2-loop renormalization group running effects for the three neutrino masses and mass matrices. We show the projected discovery reach of various LFV experiments ($\textit{i.e.}$ Mu2e, Mu3e, MEG-II, Belle-II), and specify regions that have already been excluded by the LHC searches. Our results depend strongly on whether one has a normal sneutrino hierarchy (NSH) or an inverted sneutrino hierarchy (ISH). Natural SUSY with a NSH is already excluded by MEG-2013 results while large portions of ISH have been or will soon be tested. However, LFV processes from natural SUSY with small Yukawa mixing and an ISH seem below any projected sensitivities. A substantial amount of the remaining parameter space of models with large PMNS-like sneutrino mixing will be probed by Mu2e and MEG-II experiments whereas small, CKM-like Yukawa mixing predicts LFV decays which can hide from LFV experiments.
1506.08841
Jessica Goodman
Linda M. Carpenter, Russell Colburn, and Jessica Goodman
Indirect Detection Constraints on the Model Space of Dark Matter Effective Theories
14 pages and 14 figures
Phys. Rev. D 92, 095011 (2015)
10.1103/PhysRevD.92.095011
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using limits on photon flux from Dwarf Spheroidal galaxies, we place bounds on the parameter space of models in which Dark Matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with Dark Matter couplings to third generation fermions and to pairs of Standard Model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.
[ { "created": "Mon, 29 Jun 2015 20:07:40 GMT", "version": "v1" } ]
2015-11-11
[ [ "Carpenter", "Linda M.", "" ], [ "Colburn", "Russell", "" ], [ "Goodman", "Jessica", "" ] ]
Using limits on photon flux from Dwarf Spheroidal galaxies, we place bounds on the parameter space of models in which Dark Matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with Dark Matter couplings to third generation fermions and to pairs of Standard Model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.
1003.1829
Deshan Yang
Deshan Yang
Recent Development of QCD Factorization for B-> M1 M2
4 pages. Invited plenary talk given at the 4th International Conference on Flavor Physics, Sep.24-Sep.28, 2007, Beijing.
Int.J.Mod.Phys.A23:3255-3258,2008
10.1142/S0217751X0804192X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After briefly introducing the framework of QCD factorization for B-> M1 M2 in the language of the Soft-Collinear Effective Theory, we firstly address the recent efforts on higher-order radiative corrections in QCD factorization. Then we discuss some phenomenologies in B-> V V within the framework of QCD factorization.
[ { "created": "Tue, 9 Mar 2010 08:26:26 GMT", "version": "v1" } ]
2014-11-20
[ [ "Yang", "Deshan", "" ] ]
After briefly introducing the framework of QCD factorization for B-> M1 M2 in the language of the Soft-Collinear Effective Theory, we firstly address the recent efforts on higher-order radiative corrections in QCD factorization. Then we discuss some phenomenologies in B-> V V within the framework of QCD factorization.
hep-ph/0011219
Klaus Werner
H.J. Drescher, F.M. Liu, S. Ostapchenko, T. Pierog, K. Werner
Initial Condition for QGP Evolution from NEXUS
17 pages, 24 figures
Phys.Rev. C65 (2002) 054902
10.1103/PhysRevC.65.054902
null
hep-ph nucl-th
null
We recently proposed a new approach to high energy nuclear scattering, which treats the initial stage of heavy ion collisions in a sophisticated way. We are able to calculate macroscopic quantities like energy density and velocity flow at the end of this initial stage, after the two nuclei having penetrated each other. In other words, we provide the initial conditions for a macroscopic treatment of the second stage of the collision. We address in particular the question of how to incorporate the soft component properly. We find almost perfect "Bjorken scaling": the rapidity coincides with the space-time rapidity, whereas the transverse flow is practically zero. The distribution of the energy density in the transverse plane shows typically a very "bumpy" structure.
[ { "created": "Fri, 17 Nov 2000 15:24:53 GMT", "version": "v1" }, { "created": "Fri, 1 Feb 2002 20:55:27 GMT", "version": "v2" } ]
2009-10-31
[ [ "Drescher", "H. J.", "" ], [ "Liu", "F. M.", "" ], [ "Ostapchenko", "S.", "" ], [ "Pierog", "T.", "" ], [ "Werner", "K.", "" ] ]
We recently proposed a new approach to high energy nuclear scattering, which treats the initial stage of heavy ion collisions in a sophisticated way. We are able to calculate macroscopic quantities like energy density and velocity flow at the end of this initial stage, after the two nuclei having penetrated each other. In other words, we provide the initial conditions for a macroscopic treatment of the second stage of the collision. We address in particular the question of how to incorporate the soft component properly. We find almost perfect "Bjorken scaling": the rapidity coincides with the space-time rapidity, whereas the transverse flow is practically zero. The distribution of the energy density in the transverse plane shows typically a very "bumpy" structure.
1903.10505
Kevin Kelly
Valentina De Romeri, Kevin J. Kelly, and Pedro A.N. Machado
Hunting On- and Off-Axis for Light Dark Matter with DUNE-PRISM
16 pages (including 5 appendices), 11 figures. Version 2 matches published version with significant rearrangement of results (results unchanged). Version 1 contains nuclear scattering results not present in v2
Phys. Rev. D 100, 095010 (2019)
10.1103/PhysRevD.100.095010
FERMILAB-PUB-19-116-T
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We explore the sensitivity of the Deep Underground Neutrino Experiment (DUNE) near detector and the proposed DUNE-PRISM movable near detector to sub-GeV dark matter, specifically scalar dark matter coupled to the Standard Model via a sub-GeV dark photon. We consider dark matter produced in the DUNE target that travels to the detector and scatters off electrons. By combining searches for dark matter at many off-axis positions with DUNE-PRISM, sensitivity to this scenario can be much stronger than when performing a measurement at one on-axis position.
[ { "created": "Mon, 25 Mar 2019 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 18 Nov 2019 14:58:12 GMT", "version": "v2" } ]
2019-11-19
[ [ "De Romeri", "Valentina", "" ], [ "Kelly", "Kevin J.", "" ], [ "Machado", "Pedro A. N.", "" ] ]
We explore the sensitivity of the Deep Underground Neutrino Experiment (DUNE) near detector and the proposed DUNE-PRISM movable near detector to sub-GeV dark matter, specifically scalar dark matter coupled to the Standard Model via a sub-GeV dark photon. We consider dark matter produced in the DUNE target that travels to the detector and scatters off electrons. By combining searches for dark matter at many off-axis positions with DUNE-PRISM, sensitivity to this scenario can be much stronger than when performing a measurement at one on-axis position.
hep-ph/0010118
Tatsu Takeuchi
Lay Nam Chang, Oleg Lebedev, Will Loinaz, and Tatsu Takeuchi
Constraints on Gauged B-3L_tau and Related Theories
15 pages REVTEX, 4 postscript figures, uses axodraw.sty
Phys.Rev. D63 (2001) 074013
10.1103/PhysRevD.63.074013
VPI-IPPAP-00-05
hep-ph
null
We consider extensions of the Standard Model with an extra U(1) gauge boson which couples to B-(alpha L_e + beta L_mu + gamma L_tau) with alpha + beta + gamma = 3. We show that the extra gauge boson necessarily mixes with the Z leading to potentially significant corrections to the Z-f-fbar vertex. The constraints on the size of this correction imposed by the Z-pole data from LEP and SLD are derived.
[ { "created": "Wed, 11 Oct 2000 23:45:17 GMT", "version": "v1" }, { "created": "Wed, 29 Nov 2000 17:22:53 GMT", "version": "v2" } ]
2007-05-23
[ [ "Chang", "Lay Nam", "" ], [ "Lebedev", "Oleg", "" ], [ "Loinaz", "Will", "" ], [ "Takeuchi", "Tatsu", "" ] ]
We consider extensions of the Standard Model with an extra U(1) gauge boson which couples to B-(alpha L_e + beta L_mu + gamma L_tau) with alpha + beta + gamma = 3. We show that the extra gauge boson necessarily mixes with the Z leading to potentially significant corrections to the Z-f-fbar vertex. The constraints on the size of this correction imposed by the Z-pole data from LEP and SLD are derived.
1612.05431
Kaori Fuyuto
Koichi Funakubo, Kaori Fuyuto and Eibun Senaha
Does a band structure affect sphaleron processes?
5 pages, 1 figure
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by a recent work of Tye and Wong, we examine an effect of a band structure on baryon number preservation criteria requisite for successful electroweak baryogenesis. Action of a reduced model is fully constructed including a time component of the gauge field that is missing in the original work. The band structure is estimated more precisely in wider energy range based on WKB framework with three connection formulas to find that the band structure has little effect on the criteria at around 100 GeV temperature. We also address an issue of suppression factors peculiar to the $(B+L)$-changing process in high-energy collisions at zero temperature.
[ { "created": "Fri, 16 Dec 2016 11:03:09 GMT", "version": "v1" } ]
2016-12-19
[ [ "Funakubo", "Koichi", "" ], [ "Fuyuto", "Kaori", "" ], [ "Senaha", "Eibun", "" ] ]
Inspired by a recent work of Tye and Wong, we examine an effect of a band structure on baryon number preservation criteria requisite for successful electroweak baryogenesis. Action of a reduced model is fully constructed including a time component of the gauge field that is missing in the original work. The band structure is estimated more precisely in wider energy range based on WKB framework with three connection formulas to find that the band structure has little effect on the criteria at around 100 GeV temperature. We also address an issue of suppression factors peculiar to the $(B+L)$-changing process in high-energy collisions at zero temperature.
hep-ph/9707389
Daniele Treleani
Giorgio Calucci and Daniele Treleani
Minijets and the Two-Body Parton Correlation
19 pages, plane tex, no figures
Phys.Rev. D57 (1998) 503-511
10.1103/PhysRevD.57.503
null
hep-ph
null
A large number of double parton scatterings have been recently measured by CDF. The double parton scattering process measures $\sigma_{eff}$, a non perturbative quantity related to the hadronic transverse size and with the dimensions of a cross section. The actual value measured by CDF is considerably smaller as compared with the naive expectation, namely the value of the inelastic non diffractive cross section. The small value of $\sigma_{eff}$ may be an effect of the hadron structure in transverse plane. We discuss the problem by taking into account, at all orders, the two-body parton correlations in the many-body parton distributions.
[ { "created": "Fri, 18 Jul 1997 08:15:57 GMT", "version": "v1" } ]
2009-10-30
[ [ "Calucci", "Giorgio", "" ], [ "Treleani", "Daniele", "" ] ]
A large number of double parton scatterings have been recently measured by CDF. The double parton scattering process measures $\sigma_{eff}$, a non perturbative quantity related to the hadronic transverse size and with the dimensions of a cross section. The actual value measured by CDF is considerably smaller as compared with the naive expectation, namely the value of the inelastic non diffractive cross section. The small value of $\sigma_{eff}$ may be an effect of the hadron structure in transverse plane. We discuss the problem by taking into account, at all orders, the two-body parton correlations in the many-body parton distributions.
hep-ph/0211186
Czyz Henryk
H. Czyz, J. H. Kuehn, G. Rodrigo
Radiative return at e+e- factories
5 pages, 7 figures, presented at RADCOR 2002, Kloster Banz, Sept. 8-13, 2002
Nucl.Phys.Proc.Suppl. 116 (2003) 249-253
10.1016/S0920-5632(03)80179-2
CERN-TH/2002-316, TTP02-35
hep-ph hep-ex
null
The energy dependence of the electron - positron hadronic cross section can be measured not only by a straightforward energy scan, but also by means of the radiative return method. To provide extensive comparisons between theory and experiment a Monte Carlo event generator is an indispensable tool. We have developed such a generator called PHOKHARA, which simulates e+e- -> mesons + photon(s) processes. In this paper we present its latest tests and upgrades.
[ { "created": "Tue, 12 Nov 2002 21:49:10 GMT", "version": "v1" } ]
2009-11-07
[ [ "Czyz", "H.", "" ], [ "Kuehn", "J. H.", "" ], [ "Rodrigo", "G.", "" ] ]
The energy dependence of the electron - positron hadronic cross section can be measured not only by a straightforward energy scan, but also by means of the radiative return method. To provide extensive comparisons between theory and experiment a Monte Carlo event generator is an indispensable tool. We have developed such a generator called PHOKHARA, which simulates e+e- -> mesons + photon(s) processes. In this paper we present its latest tests and upgrades.
hep-ph/0607069
Goran Duplancic
Goran Duplancic, Bene Nizic
NLO perturbative QCD predictions for gamma gamma -> M+ M- (M=pi,K)
4 pages, 4 figures; parts rewritten, references and comments added, version as accepted for publication
Phys.Rev.Lett. 97 (2006) 142003
10.1103/PhysRevLett.97.142003
IRB-TH-2/06
hep-ph hep-ex
null
We report the first complete leading-twist next-to-leading-order perturbative QCD predictions for the two-photon exclusive channels gamma gamma -> M+ M- (M=pi,K) at large momentum transfer. The asymptotic distribution amplitude is utilized as a candidate form for the nonperturbative dynamical input. Comparison of the obtained results with the existing experimental data does not provide sufficiently clear evidence to support the applicability of the hard-scattering approach at currently accessible energies.
[ { "created": "Thu, 6 Jul 2006 17:45:22 GMT", "version": "v1" }, { "created": "Wed, 6 Sep 2006 16:31:34 GMT", "version": "v2" } ]
2009-11-11
[ [ "Duplancic", "Goran", "" ], [ "Nizic", "Bene", "" ] ]
We report the first complete leading-twist next-to-leading-order perturbative QCD predictions for the two-photon exclusive channels gamma gamma -> M+ M- (M=pi,K) at large momentum transfer. The asymptotic distribution amplitude is utilized as a candidate form for the nonperturbative dynamical input. Comparison of the obtained results with the existing experimental data does not provide sufficiently clear evidence to support the applicability of the hard-scattering approach at currently accessible energies.
hep-ph/0302107
Maria Jose Herrero
Ana M. Curiel, Maria J. Herrero and David Temes
Non-decoupling effects of SUSY in the physics of Higgs bosons and their phenomenological implications
Invited talk given by M. J. Herrero at the X Mexican School of Particles and Fields, Playa del Carmen, Mexico, November 2002
AIP Conf.Proc. 670 (2003) 306-314
10.1063/1.1594348
null
hep-ph
null
We consider a plausible scenario in the Minimal Supersymmetric Standard Model (MSSM) where all the genuine supersymmetric (SUSY) particles are heavier than the electroweak scale. In this situation, indirect searches via their radiative corrections to low energy observables are complementary to direct searches, and they can be crucial if the SUSY masses are at the TeV energy range. We summarize the most relevant heavy SUSY radiative effects in Higgs boson physics and emphasize those that manifest a non-decoupling behaviour. We focus, in particular, on the SUSY-QCD non-decoupling effects in fermionic Higgs decays, flavour changing Higgs decays and Yukawa couplings. Some of their phenomenological implications at future colliders are also studied.
[ { "created": "Thu, 13 Feb 2003 20:05:24 GMT", "version": "v1" } ]
2009-11-10
[ [ "Curiel", "Ana M.", "" ], [ "Herrero", "Maria J.", "" ], [ "Temes", "David", "" ] ]
We consider a plausible scenario in the Minimal Supersymmetric Standard Model (MSSM) where all the genuine supersymmetric (SUSY) particles are heavier than the electroweak scale. In this situation, indirect searches via their radiative corrections to low energy observables are complementary to direct searches, and they can be crucial if the SUSY masses are at the TeV energy range. We summarize the most relevant heavy SUSY radiative effects in Higgs boson physics and emphasize those that manifest a non-decoupling behaviour. We focus, in particular, on the SUSY-QCD non-decoupling effects in fermionic Higgs decays, flavour changing Higgs decays and Yukawa couplings. Some of their phenomenological implications at future colliders are also studied.
1712.04481
Christoph Englert
Christoph Englert, Stefan Hild, Michael Spannowsky
Particle Physics with Gravitational Wave Detector Technology
6 pages, 5 figures, v2: references added, published version, v3: references added
null
10.1209/0295-5075/123/41001
IPPP/17/96
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational wave detector technology provides high-precision measurement apparatuses that, if combined with a modulated particle source, have the potential to measure and constrain particle interactions in a novel way, by measuring the pressure caused by scattering particle beams off the mirror material. Such a measurement does not rely on tagging a final state. This strategy has the potential to allow us to explore novel ways to constrain the presence of new interactions beyond the Standard Model of Particle Physics and provide additional constraints to poorly understood cross sections in the non-perturbative regime of QCD and Nuclear Physics, which are limiting factors of dark matter and neutrino physics searches. Beyond high-energy physics, if technically feasible, the proposed method to measure nucleon-nucleon interactions can lead to practical applications in material and medical sciences.
[ { "created": "Tue, 12 Dec 2017 19:38:49 GMT", "version": "v1" }, { "created": "Tue, 25 Sep 2018 09:57:50 GMT", "version": "v2" }, { "created": "Fri, 26 Oct 2018 12:59:09 GMT", "version": "v3" } ]
2018-10-29
[ [ "Englert", "Christoph", "" ], [ "Hild", "Stefan", "" ], [ "Spannowsky", "Michael", "" ] ]
Gravitational wave detector technology provides high-precision measurement apparatuses that, if combined with a modulated particle source, have the potential to measure and constrain particle interactions in a novel way, by measuring the pressure caused by scattering particle beams off the mirror material. Such a measurement does not rely on tagging a final state. This strategy has the potential to allow us to explore novel ways to constrain the presence of new interactions beyond the Standard Model of Particle Physics and provide additional constraints to poorly understood cross sections in the non-perturbative regime of QCD and Nuclear Physics, which are limiting factors of dark matter and neutrino physics searches. Beyond high-energy physics, if technically feasible, the proposed method to measure nucleon-nucleon interactions can lead to practical applications in material and medical sciences.
1105.4611
Yue Zhang
Alejandra Melfo, Miha Nemevsek, Fabrizio Nesti, Goran Senjanovic, Yue Zhang
Inert Doublet Dark Matter and Mirror/Extra Families after Xenon100
10 pages, 7 figures; reference added
Phys.Rev.D84:034009,2011
10.1103/PhysRevD.84.034009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was shown recently that mirror fermions, naturally present in a number of directions for new physics, seem to require an inert scalar doublet in order to pass the electroweak precision tests. This provides a further motivation for considering the inert doublet as a dark matter candidate. Moreover, the presence of extra families enhances the Standard Model Higgs-nucleon coupling, which has crucial impact on the Higgs and dark matter searches. We study the limits on the inert dark matter mass in view of recent Xenon100 data. We find that the mass of the inert dark matter must lie in a very narrow window 74-76 GeV while the Higgs must weigh more than 400 GeV. For the sake of completeness we discuss the cases with fewer extra families, where the possibility of a light Higgs boson opens up, enlarging the dark matter mass window to m_h/2-76 GeV. We find that Xenon100 constrains the DM-Higgs interaction, which in turn implies a lower bound on the monochromatic gamma-ray flux from DM annihilation in the galactic halo. For the mirror case, the predicted annihilation cross section lies a factor of 4-5 below the current limit set by Fermi LAT, thus providing a promising indirect detection signal.
[ { "created": "Mon, 23 May 2011 20:00:04 GMT", "version": "v1" }, { "created": "Fri, 27 May 2011 21:45:20 GMT", "version": "v2" } ]
2011-09-07
[ [ "Melfo", "Alejandra", "" ], [ "Nemevsek", "Miha", "" ], [ "Nesti", "Fabrizio", "" ], [ "Senjanovic", "Goran", "" ], [ "Zhang", "Yue", "" ] ]
It was shown recently that mirror fermions, naturally present in a number of directions for new physics, seem to require an inert scalar doublet in order to pass the electroweak precision tests. This provides a further motivation for considering the inert doublet as a dark matter candidate. Moreover, the presence of extra families enhances the Standard Model Higgs-nucleon coupling, which has crucial impact on the Higgs and dark matter searches. We study the limits on the inert dark matter mass in view of recent Xenon100 data. We find that the mass of the inert dark matter must lie in a very narrow window 74-76 GeV while the Higgs must weigh more than 400 GeV. For the sake of completeness we discuss the cases with fewer extra families, where the possibility of a light Higgs boson opens up, enlarging the dark matter mass window to m_h/2-76 GeV. We find that Xenon100 constrains the DM-Higgs interaction, which in turn implies a lower bound on the monochromatic gamma-ray flux from DM annihilation in the galactic halo. For the mirror case, the predicted annihilation cross section lies a factor of 4-5 below the current limit set by Fermi LAT, thus providing a promising indirect detection signal.
hep-ph/9409302
Rachel Jeannerot
Anne-Christine DAVIS and Rachel JEANNEROT
Scattering off an SO(10) cosmic string
20 pages
Phys.Rev. D52 (1995) 1944-1954
10.1103/PhysRevD.52.1944
DAMTP 94-52
hep-ph
null
The scattering of fermions from the abelian string arising during the phase transition $SO(10) \rightarrow SU(5) \times Z_2$ induced by the Higgs in the 126 representation is studied. Elastic cross-sections and baryon number violating cross-sections due to the coupling to gauge fields in the core of the string are computed by both a first quantised method and a perturbative second quantised method. The elastic cross-sections are found to be Aharonov-Bohm type. However, there is a marked asymmetry between the scattering cross-sections for left and right handed fields. The catalysis cross-sections are small, depending on the grand unified scale. If cosmic strings were observed our results could help tie down the underlying gauge group.
[ { "created": "Tue, 13 Sep 1994 18:26:56 GMT", "version": "v1" } ]
2009-10-28
[ [ "DAVIS", "Anne-Christine", "" ], [ "JEANNEROT", "Rachel", "" ] ]
The scattering of fermions from the abelian string arising during the phase transition $SO(10) \rightarrow SU(5) \times Z_2$ induced by the Higgs in the 126 representation is studied. Elastic cross-sections and baryon number violating cross-sections due to the coupling to gauge fields in the core of the string are computed by both a first quantised method and a perturbative second quantised method. The elastic cross-sections are found to be Aharonov-Bohm type. However, there is a marked asymmetry between the scattering cross-sections for left and right handed fields. The catalysis cross-sections are small, depending on the grand unified scale. If cosmic strings were observed our results could help tie down the underlying gauge group.
hep-ph/0502039
Philippe de Forcrand
Ph. de Forcrand (ETH Zurich and CERN) and O. Jahn (MIT)
The baryon static potential from lattice QCD
6 pages, 4 figures; talk presented at BARYONS'04, Paris, Oct. 2004
Nucl.Phys. A755 (2005) 475-480
10.1016/j.nuclphysa.2005.03.127
CERN-PH-TH/2005-020
hep-ph hep-lat nucl-th
null
Lattice QCD simulations offer the possibility of determining the potential between three static quarks from first principles. We review the status of such simulations, and the relative standing of the two theoretical proposals for the baryonic potential: the Delta law (sum of two-body terms) and the Y law (length of three flux strings joined together at a junction). We also present new results on the leading Luscher-like corrections to the asymptotic linear potential.
[ { "created": "Thu, 3 Feb 2005 17:38:08 GMT", "version": "v1" } ]
2015-06-25
[ [ "de Forcrand", "Ph.", "", "ETH Zurich and CERN" ], [ "Jahn", "O.", "", "MIT" ] ]
Lattice QCD simulations offer the possibility of determining the potential between three static quarks from first principles. We review the status of such simulations, and the relative standing of the two theoretical proposals for the baryonic potential: the Delta law (sum of two-body terms) and the Y law (length of three flux strings joined together at a junction). We also present new results on the leading Luscher-like corrections to the asymptotic linear potential.
hep-ph/9604359
Sergey Goloskokov
S.V.Goloskokov
Effects of Quark-Pomeron Coupling Structure in Diffractive Deep Inelastic Scattering
15 pages, latex, 5-Ps figures
null
null
null
hep-ph
null
We study the contribution of diffractive $Q \bar Q$ production to the $F_2^D$ proton structure function and the longitudinal double-spin asymmetry in polarized deep--inelastic $lp$ scattering. We show the strong dependence of the $F_2^D$ structure function and the $A_{ll}$ asymmetry on the quark--pomeron coupling structure.
[ { "created": "Fri, 19 Apr 1996 14:26:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Goloskokov", "S. V.", "" ] ]
We study the contribution of diffractive $Q \bar Q$ production to the $F_2^D$ proton structure function and the longitudinal double-spin asymmetry in polarized deep--inelastic $lp$ scattering. We show the strong dependence of the $F_2^D$ structure function and the $A_{ll}$ asymmetry on the quark--pomeron coupling structure.
1410.6620
Roman Nevzorov
C. D. Froggatt, R. Nevzorov, H. B. Nielsen, A. W. Thomas
On the smallness of the cosmological constant
Parallel talk at ICHEP 2014, Valencia, Spain, July 2014, 6 pages, 1 figure
null
null
ADP-14-31-T890
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In N=1 supergravity the scalar potential of the hidden sector may have degenerate supersymmetric (SUSY) and non-supersymmetric Minkowski vacua. In this case local SUSY in the second supersymmetric Minkowski phase can be broken dynamically. Assuming that such a second phase and the phase associated with the physical vacuum are exactly degenerate, we estimate the value of the cosmological constant. We argue that the observed value of the dark energy density can be reproduced if in the second vacuum local SUSY breaking is induced by gaugino condensation at a scale which is just slightly lower than \Lambda_{QCD} in the physical vacuum. The presence of a third degenerate vacuum, in which local SUSY and electroweak (EW) symmetry are broken near the Planck scale, may lead to small values of the quartic Higgs self--coupling and the corresponding beta function at the Planck scale in the phase in which we live.
[ { "created": "Fri, 24 Oct 2014 08:48:09 GMT", "version": "v1" } ]
2014-10-27
[ [ "Froggatt", "C. D.", "" ], [ "Nevzorov", "R.", "" ], [ "Nielsen", "H. B.", "" ], [ "Thomas", "A. W.", "" ] ]
In N=1 supergravity the scalar potential of the hidden sector may have degenerate supersymmetric (SUSY) and non-supersymmetric Minkowski vacua. In this case local SUSY in the second supersymmetric Minkowski phase can be broken dynamically. Assuming that such a second phase and the phase associated with the physical vacuum are exactly degenerate, we estimate the value of the cosmological constant. We argue that the observed value of the dark energy density can be reproduced if in the second vacuum local SUSY breaking is induced by gaugino condensation at a scale which is just slightly lower than \Lambda_{QCD} in the physical vacuum. The presence of a third degenerate vacuum, in which local SUSY and electroweak (EW) symmetry are broken near the Planck scale, may lead to small values of the quartic Higgs self--coupling and the corresponding beta function at the Planck scale in the phase in which we live.
1808.08979
Jennifer Thompson
Theo Heimel, Gregor Kasieczka, Tilman Plehn, Jennifer M Thompson
QCD or What?
11 figures, added references
SciPost Phys. 6, 030 (2019)
10.21468/SciPostPhys.6.3.030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Autoencoder networks, trained only on QCD jets, can be used to search for anomalies in jet-substructure. We show how, based either on images or on 4-vectors, they identify jets from decays of arbitrary heavy resonances. To control the backgrounds and the underlying systematics we can de-correlate the jet mass using an adversarial network. Such an adversarial autoencoder allows for a general and at the same time easily controllable search for new physics. Ideally, it can be trained and applied to data in the same phase space region, allowing us to efficiently search for new physics using un-supervised learning.
[ { "created": "Mon, 27 Aug 2018 18:09:36 GMT", "version": "v1" }, { "created": "Thu, 4 Oct 2018 15:28:36 GMT", "version": "v2" }, { "created": "Mon, 14 Jan 2019 16:49:52 GMT", "version": "v3" } ]
2019-03-13
[ [ "Heimel", "Theo", "" ], [ "Kasieczka", "Gregor", "" ], [ "Plehn", "Tilman", "" ], [ "Thompson", "Jennifer M", "" ] ]
Autoencoder networks, trained only on QCD jets, can be used to search for anomalies in jet-substructure. We show how, based either on images or on 4-vectors, they identify jets from decays of arbitrary heavy resonances. To control the backgrounds and the underlying systematics we can de-correlate the jet mass using an adversarial network. Such an adversarial autoencoder allows for a general and at the same time easily controllable search for new physics. Ideally, it can be trained and applied to data in the same phase space region, allowing us to efficiently search for new physics using un-supervised learning.
1511.06215
Hiren Patel
Manfred Lindner, Hiren H. Patel, Branimir Radov\v{c}i\'c
Electroweak Absolute, Meta-, and Thermal Stability in Neutrino Mass Models
7 pages, 4 figures, match published version
Phys. Rev. D 93, 073005 (2016)
10.1103/PhysRevD.93.073005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the stability of the electroweak vacuum in neutrino mass models containing right handed neutrinos or fermionic isotriplets. In addition to considering absolute stability, we place limits on the Yukawa couplings of new fermions based on metastability and thermal stability in the early Universe. Our results reveal that the upper limits on the neutrino Yukawa couplings can change significantly when the top quark mass is allowed to vary within the experimental range of uncertainty in its determination.
[ { "created": "Thu, 19 Nov 2015 15:45:51 GMT", "version": "v1" }, { "created": "Sat, 26 Mar 2016 12:31:59 GMT", "version": "v2" } ]
2016-04-20
[ [ "Lindner", "Manfred", "" ], [ "Patel", "Hiren H.", "" ], [ "Radovčić", "Branimir", "" ] ]
We analyze the stability of the electroweak vacuum in neutrino mass models containing right handed neutrinos or fermionic isotriplets. In addition to considering absolute stability, we place limits on the Yukawa couplings of new fermions based on metastability and thermal stability in the early Universe. Our results reveal that the upper limits on the neutrino Yukawa couplings can change significantly when the top quark mass is allowed to vary within the experimental range of uncertainty in its determination.
1506.04368
Hong-Shi Zong
Yi-Lun Du, Ya Lu, Shu-Sheng Xu, Zhu-Fang Cui, Chao Shi, and Hong-Shi Zong
Susceptibilities and critical exponents within the Nambu--Jona-Lasinio model
13 pages, 6 figures
null
10.1142/S0217751X15501997
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the mean field approximation of (2+1)-flavor Nambu--Jona-Lasinio model, we strictly derive several sets of coupled equations for the chiral susceptibility, the quark number susceptibility, etc. at finite temperature and quark chemical potential. The critical exponents of these susceptibilities in the vicinity of the QCD critical end point (CEP) are presented in SU(2) and SU(3) cases, respectively. It is found that these various susceptibilities share almost the same critical behavior near the CEP. The comparisons between the critical exponents for the order parameters and the theoretical predictions are also included.
[ { "created": "Sun, 14 Jun 2015 09:41:25 GMT", "version": "v1" }, { "created": "Sat, 28 Nov 2015 13:21:13 GMT", "version": "v2" } ]
2015-12-01
[ [ "Du", "Yi-Lun", "" ], [ "Lu", "Ya", "" ], [ "Xu", "Shu-Sheng", "" ], [ "Cui", "Zhu-Fang", "" ], [ "Shi", "Chao", "" ], [ "Zong", "Hong-Shi", "" ] ]
In the mean field approximation of (2+1)-flavor Nambu--Jona-Lasinio model, we strictly derive several sets of coupled equations for the chiral susceptibility, the quark number susceptibility, etc. at finite temperature and quark chemical potential. The critical exponents of these susceptibilities in the vicinity of the QCD critical end point (CEP) are presented in SU(2) and SU(3) cases, respectively. It is found that these various susceptibilities share almost the same critical behavior near the CEP. The comparisons between the critical exponents for the order parameters and the theoretical predictions are also included.
hep-ph/0003092
Amarjit Soni
Amarjit Soni
Hadronic matrix elements from the lattice
8 pages, Invited talk given at the Third International Conference on B Physics and CP Violation, Taipei, Dec. 3-7, 99
null
10.1142/9789812791870_0046
BNL-HET-00/3
hep-ph
null
Lattice matrix elements are briefly reviewed. In the quenched approximation $f_B$, $B_B$ and $B_K$ are now under good control. Experimental hints for $f^{\rm expt}_{D_S}> f^{\rm QQCD}_{D_S}$ are noted; precise determination of $f_{D_S}$ from experiment as well as from the lattice is strongly advocated. Lattice calculations of the form factor for $B\to\pi\ell\nu$ at relatively large value of $q^2$ have made good progress and should be useful in conjunction with precise measurement of the differential spectra expected from $B$-factories. Recent attempt at $K\to \pi\pi$ using staggered quarks is briefly discussed; use of non-perturbative renormalization, improved actions and operators with staggered quarks is emphasized. Due to the good chiral behavior of domain wall quarks it would be useful to study $K\to \pi\pi$ with this discretization.
[ { "created": "Fri, 10 Mar 2000 04:40:22 GMT", "version": "v1" } ]
2016-11-23
[ [ "Soni", "Amarjit", "" ] ]
Lattice matrix elements are briefly reviewed. In the quenched approximation $f_B$, $B_B$ and $B_K$ are now under good control. Experimental hints for $f^{\rm expt}_{D_S}> f^{\rm QQCD}_{D_S}$ are noted; precise determination of $f_{D_S}$ from experiment as well as from the lattice is strongly advocated. Lattice calculations of the form factor for $B\to\pi\ell\nu$ at relatively large value of $q^2$ have made good progress and should be useful in conjunction with precise measurement of the differential spectra expected from $B$-factories. Recent attempt at $K\to \pi\pi$ using staggered quarks is briefly discussed; use of non-perturbative renormalization, improved actions and operators with staggered quarks is emphasized. Due to the good chiral behavior of domain wall quarks it would be useful to study $K\to \pi\pi$ with this discretization.
1210.6890
Peinado Eduardo
E. Peinado
Discrete dark matter mechanism
Contribution to the Proceedings of PASCOS2012 conference, 6 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the Discrete Dark Matter mechanism (DDM) which consist on the stability of the dark matter from a spontaneous breaking of a flavor symmetry group into one of its subgroups. Here we present the inclusion of the quarks on this mechanism promoting the quarks to transform non-trivial under the flavor group.
[ { "created": "Thu, 25 Oct 2012 16:11:04 GMT", "version": "v1" } ]
2012-10-26
[ [ "Peinado", "E.", "" ] ]
We present the Discrete Dark Matter mechanism (DDM) which consist on the stability of the dark matter from a spontaneous breaking of a flavor symmetry group into one of its subgroups. Here we present the inclusion of the quarks on this mechanism promoting the quarks to transform non-trivial under the flavor group.
0806.0884
Boyang Liu
Boyang Liu
Gauge Invariance of the Muonium-Antimuonium Oscillation Time Scale and Limits on Right-Handed Neutrino Masses
17 pages, 6 figures, Latex
Mod.Phys.Lett.A24:335-348,2009
10.1142/S021773230903000X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gauge invariance of the muonium-antimuonium ($M\bar{M}$) oscillation time scale is explicitly demonstrated in the Standard Model modified only by the inclusion of singlet right-handed neutrinos and allowing for general renormalizable interactions. The see-saw mechanism is exploited resulting in three light Majorana neutrinos and three heavy Majorana neutrinos with mass scale $M_R\gg M_W$. The leading order matrix element contribution to the $M\bar{M}$ oscillation process is computed in $R_\xi$ gauge and shown to be $\xi$ independent thereby establishing the gauge invariance to this order. Present experimental limits resulting from the non-observation of the oscillation process sets a lower limit on $M_R$ roughly of order 600 GeV.
[ { "created": "Thu, 5 Jun 2008 01:37:16 GMT", "version": "v1" }, { "created": "Fri, 6 Jun 2008 21:08:17 GMT", "version": "v2" }, { "created": "Wed, 10 Dec 2008 00:46:55 GMT", "version": "v3" } ]
2009-03-12
[ [ "Liu", "Boyang", "" ] ]
The gauge invariance of the muonium-antimuonium ($M\bar{M}$) oscillation time scale is explicitly demonstrated in the Standard Model modified only by the inclusion of singlet right-handed neutrinos and allowing for general renormalizable interactions. The see-saw mechanism is exploited resulting in three light Majorana neutrinos and three heavy Majorana neutrinos with mass scale $M_R\gg M_W$. The leading order matrix element contribution to the $M\bar{M}$ oscillation process is computed in $R_\xi$ gauge and shown to be $\xi$ independent thereby establishing the gauge invariance to this order. Present experimental limits resulting from the non-observation of the oscillation process sets a lower limit on $M_R$ roughly of order 600 GeV.
1109.2052
Eugene Loginov
E.K. Loginov
Standard Model gauge coupling unification
17 page, LaTeX, no figures
Eur. Phys. J. C73 (2013) 2293
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the low energy evolution of coupling constants of the standard model and show that gauge coupling unification can be achieved at the electroweak scale with a suitable normalization. We choose the grand unification group to be the semidirect product of Spin(8) by S_3. In this case the three low energy gauge couplings and the two scalar self-couplings are determined in terms of two independent parameters. In particular, it gives a precise prediction for the mass of the Higgs boson.
[ { "created": "Fri, 9 Sep 2011 16:02:19 GMT", "version": "v1" }, { "created": "Tue, 15 May 2012 18:18:07 GMT", "version": "v2" }, { "created": "Tue, 29 Jan 2013 14:11:24 GMT", "version": "v3" } ]
2013-01-30
[ [ "Loginov", "E. K.", "" ] ]
We study the low energy evolution of coupling constants of the standard model and show that gauge coupling unification can be achieved at the electroweak scale with a suitable normalization. We choose the grand unification group to be the semidirect product of Spin(8) by S_3. In this case the three low energy gauge couplings and the two scalar self-couplings are determined in terms of two independent parameters. In particular, it gives a precise prediction for the mass of the Higgs boson.
1711.08437
Yevgeny Kats
Gian F. Giudice, Yevgeny Kats, Matthew McCullough, Riccardo Torre, Alfredo Urbano
Clockwork / Linear Dilaton: Structure and Phenomenology
39 pages + appendices, 27 figures; v2: minor improvements; published version
JHEP 1806 (2018) 009
10.1007/JHEP06(2018)009
CERN-TH-2017-219
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The linear dilaton geometry in five dimensions, rediscovered recently in the continuum limit of the clockwork model, may offer a solution to the hierarchy problem which is qualitatively different from other extra-dimensional scenarios and leads to distinctive signatures at the LHC. We discuss the structure of the theory, in particular aspects of naturalness and UV completion, and then explore its phenomenology, suggesting novel strategies for experimental searches. In particular, we propose to analyze the diphoton and dilepton invariant mass spectra in Fourier space in order to identify an approximately periodic structure of resonant peaks. Among other signals, we highlight displaced decays from resonantly-produced long-lived states and high-multiplicity final states from cascade decays of excited gravitons.
[ { "created": "Wed, 22 Nov 2017 18:34:36 GMT", "version": "v1" }, { "created": "Thu, 14 Jun 2018 14:07:07 GMT", "version": "v2" } ]
2018-06-15
[ [ "Giudice", "Gian F.", "" ], [ "Kats", "Yevgeny", "" ], [ "McCullough", "Matthew", "" ], [ "Torre", "Riccardo", "" ], [ "Urbano", "Alfredo", "" ] ]
The linear dilaton geometry in five dimensions, rediscovered recently in the continuum limit of the clockwork model, may offer a solution to the hierarchy problem which is qualitatively different from other extra-dimensional scenarios and leads to distinctive signatures at the LHC. We discuss the structure of the theory, in particular aspects of naturalness and UV completion, and then explore its phenomenology, suggesting novel strategies for experimental searches. In particular, we propose to analyze the diphoton and dilepton invariant mass spectra in Fourier space in order to identify an approximately periodic structure of resonant peaks. Among other signals, we highlight displaced decays from resonantly-produced long-lived states and high-multiplicity final states from cascade decays of excited gravitons.
hep-ph/0608163
Jennifer Kile
Rebecca J. Erwin, Jennifer Kile, Michael J. Ramsey-Musolf, Peng Wang
Constraints on Muon Decay Parameters from Neutrino Mass
4 pages, contribution to the proceedings of CIPANP 2006 (May 30-June 3, 2006), Rio Grande, Puerto Rico
null
10.1063/1.2220417
Caltech MAP-325, CALT-68-2608
hep-ph
null
We derive model-independent constraints on chirality-changing terms in the muon decay Lagrangian using limits on neutrino mass. We consider all dimension-six operators invariant under the gauge symmetry of the Standard Model which contribute to either a Dirac neutrino mass or muon decay. Taking an upper limit on neutrino mass of 1 eV, we derive limits on the contributions of chirality-changing operators to the Michel parameters four orders of magnitude tighter than the current experimental constraints. We also identify two operators which, due to their flavor structure, are not constrained by neutrino mass. If near-future experiments find contributions to muon decay from these operators, it could indicate interesting flavor structure in physics beyond the SM.
[ { "created": "Tue, 15 Aug 2006 00:21:38 GMT", "version": "v1" } ]
2009-11-11
[ [ "Erwin", "Rebecca J.", "" ], [ "Kile", "Jennifer", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Wang", "Peng", "" ] ]
We derive model-independent constraints on chirality-changing terms in the muon decay Lagrangian using limits on neutrino mass. We consider all dimension-six operators invariant under the gauge symmetry of the Standard Model which contribute to either a Dirac neutrino mass or muon decay. Taking an upper limit on neutrino mass of 1 eV, we derive limits on the contributions of chirality-changing operators to the Michel parameters four orders of magnitude tighter than the current experimental constraints. We also identify two operators which, due to their flavor structure, are not constrained by neutrino mass. If near-future experiments find contributions to muon decay from these operators, it could indicate interesting flavor structure in physics beyond the SM.
hep-ph/9410206
George Siopsis
George Siopsis
Particle Hamiltonian and Perturbative Gauge Theories
13 pages LaTeX, Univ. of Tennessee preprint UTHEP-94-0703
Phys.Lett.B342:224-232,1995
10.1016/0370-2693(94)01340-I
null
hep-ph hep-th
null
We discuss the Hamiltonian formulation of the Schwinger proper-time method of calculating Green functions in gauge theories. Instead of calculating Feynman diagrams, we solve the corresponding Dyson-Schwinger equations. We express the solutions in terms of vertex operators, which consist of the zero modes of the vertex operators appearing in string theories. We show how color decomposition arises in this formalism at tree level. At the one-loop level, we arrive at expressions similar to those obtained in the background gauge. In both cases, no special gauge-fixing procedure is needed.
[ { "created": "Mon, 3 Oct 1994 21:21:39 GMT", "version": "v1" } ]
2011-07-19
[ [ "Siopsis", "George", "" ] ]
We discuss the Hamiltonian formulation of the Schwinger proper-time method of calculating Green functions in gauge theories. Instead of calculating Feynman diagrams, we solve the corresponding Dyson-Schwinger equations. We express the solutions in terms of vertex operators, which consist of the zero modes of the vertex operators appearing in string theories. We show how color decomposition arises in this formalism at tree level. At the one-loop level, we arrive at expressions similar to those obtained in the background gauge. In both cases, no special gauge-fixing procedure is needed.
2109.09933
Zhou-Run Zhu
Zhou-Run Zhu, Jun Chen, and Defu Hou
Gravitational waves from holographic QCD phase transition with gluon condensate
16 pages, 2 figures
null
10.1140/epja/s10050-022-00754-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we discuss the holographic first order QCD phase transition with gluon condensate and the generation of gravitational waves (GWs) from the phase transition. The first order QCD phase transition is dual to the first order Hawking-Page phase transition from holography. We study the first order Hawking-Page phase transition from the thermal dilatonic phase to the dilatonic black hole phase and find the phase transition temperature is proportional to the gluon condensate. After substituting into the phenomenological value of gluon condensate from QCD sum rules, we find $T_c=155.38\ MeV$. In further research, we study the GWs generated from holographic cosmic first order QCD phase transition with gluon condensate and the produced GWs might be detected by the International Pulsar Timing Array, Square Kilometre Array and Big-Bang Observer. Moreover, the gluon condensate suppresses the energy density of total GWs and peak frequency.
[ { "created": "Tue, 21 Sep 2021 03:16:34 GMT", "version": "v1" }, { "created": "Mon, 15 Jan 2024 11:36:45 GMT", "version": "v2" } ]
2024-01-17
[ [ "Zhu", "Zhou-Run", "" ], [ "Chen", "Jun", "" ], [ "Hou", "Defu", "" ] ]
In this paper, we discuss the holographic first order QCD phase transition with gluon condensate and the generation of gravitational waves (GWs) from the phase transition. The first order QCD phase transition is dual to the first order Hawking-Page phase transition from holography. We study the first order Hawking-Page phase transition from the thermal dilatonic phase to the dilatonic black hole phase and find the phase transition temperature is proportional to the gluon condensate. After substituting into the phenomenological value of gluon condensate from QCD sum rules, we find $T_c=155.38\ MeV$. In further research, we study the GWs generated from holographic cosmic first order QCD phase transition with gluon condensate and the produced GWs might be detected by the International Pulsar Timing Array, Square Kilometre Array and Big-Bang Observer. Moreover, the gluon condensate suppresses the energy density of total GWs and peak frequency.
1003.4266
Julien Baglio
Julien Baglio, Abdelhak Djouadi
Predictions for Higgs production at the Tevatron and the associated uncertainties
40 pages, 12 figures. A few typos are corrected and some updated numbers are provided
JHEP 1010:064,2010
10.1007/JHEP10(2010)064
CERN-PH-TH/2010-051, LPT Orsay 10-15
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update the theoretical predictions for the production cross sections of the Standard Model Higgs boson at the Fermilab Tevatron collider, focusing on the two main search channels, the gluon-gluon fusion mechanism $gg \to H$ and the Higgs-strahlung processes $q \bar q \to VH$ with $V=W/Z$, including all relevant higher order QCD and electroweak corrections in perturbation theory. We then estimate the various uncertainties affecting these predictions: the scale uncertainties which are viewed as a measure of the unknown higher order effects, the uncertainties from the parton distribution functions and the related errors on the strong coupling constant, as well as the uncertainties due to the use of an effective theory approach in the determination of the radiative corrections in the $gg \to H$ process at next-to-next-to-leading order. We find that while the cross sections are well under control in the Higgs--strahlung processes, the theoretical uncertainties are rather large in the case of the gluon-gluon fusion channel, possibly shifting the central values of the next-to-next-to-leading order cross sections by more than $\approx 40%$. These uncertainties are thus significantly larger than the $\approx 10%$ error assumed by the CDF and D0 experiments in their recent analysis that has excluded the Higgs mass range $M_H=$162-166 GeV at the 95% confidence level. These exclusion limits should be, therefore, reconsidered in the light of these large theoretical uncertainties.
[ { "created": "Mon, 22 Mar 2010 20:11:53 GMT", "version": "v1" }, { "created": "Tue, 7 Sep 2010 18:59:04 GMT", "version": "v2" } ]
2015-03-13
[ [ "Baglio", "Julien", "" ], [ "Djouadi", "Abdelhak", "" ] ]
We update the theoretical predictions for the production cross sections of the Standard Model Higgs boson at the Fermilab Tevatron collider, focusing on the two main search channels, the gluon-gluon fusion mechanism $gg \to H$ and the Higgs-strahlung processes $q \bar q \to VH$ with $V=W/Z$, including all relevant higher order QCD and electroweak corrections in perturbation theory. We then estimate the various uncertainties affecting these predictions: the scale uncertainties which are viewed as a measure of the unknown higher order effects, the uncertainties from the parton distribution functions and the related errors on the strong coupling constant, as well as the uncertainties due to the use of an effective theory approach in the determination of the radiative corrections in the $gg \to H$ process at next-to-next-to-leading order. We find that while the cross sections are well under control in the Higgs--strahlung processes, the theoretical uncertainties are rather large in the case of the gluon-gluon fusion channel, possibly shifting the central values of the next-to-next-to-leading order cross sections by more than $\approx 40%$. These uncertainties are thus significantly larger than the $\approx 10%$ error assumed by the CDF and D0 experiments in their recent analysis that has excluded the Higgs mass range $M_H=$162-166 GeV at the 95% confidence level. These exclusion limits should be, therefore, reconsidered in the light of these large theoretical uncertainties.
1408.4411
Yevgen Kravets
Yevgen Kravets
Radiation reaction in strong fields from an alternative perspective
null
null
null
null
hep-ph physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Current classical theory of radiation reaction has several deficiencies such as "runaway solutions" and violation of causality. The Landau-Lifshitz approximation to the exact equation introduced by Lorentz, Abraham and Dirac is widely used, though questions remain regarding its domain of validity. This thesis explores an alternative treatment of the motion of a radiating electron, based on an equation first proposed by Ford and O'Connell. A general condition is found for solutions of this equation to deviate from those of Landau-Lifshitz. By exploring radiation reaction effects on a particle colliding with an ultra-intense laser pulse we show that the regime where there is a significant deviation of these two approaches can never be reached with existing or proposed laser facilities. The methods used to explore single particle interaction with an intense laser pulse are extended to describe the interaction of a particle bunch with various realistic laser pulses. We find that the interaction leads to a decrease in average momentum and relative momentum spread. However, the decrease appears to be independent of the length of the pulse and depends only on the energy in the pulse regardless of how it is distributed. Radiation reaction effects occuring during the scattering of an electron by a heavy, highly-charged nucleus are studied. Radiation reaction is seen to affect the particle's motion. We find noticeable differences between the predictions of the Ford-O'Connell and Landau-Lifshitz equations, albeit in regimes where quantum effects would be important.
[ { "created": "Tue, 19 Aug 2014 18:04:40 GMT", "version": "v1" } ]
2014-08-20
[ [ "Kravets", "Yevgen", "" ] ]
Current classical theory of radiation reaction has several deficiencies such as "runaway solutions" and violation of causality. The Landau-Lifshitz approximation to the exact equation introduced by Lorentz, Abraham and Dirac is widely used, though questions remain regarding its domain of validity. This thesis explores an alternative treatment of the motion of a radiating electron, based on an equation first proposed by Ford and O'Connell. A general condition is found for solutions of this equation to deviate from those of Landau-Lifshitz. By exploring radiation reaction effects on a particle colliding with an ultra-intense laser pulse we show that the regime where there is a significant deviation of these two approaches can never be reached with existing or proposed laser facilities. The methods used to explore single particle interaction with an intense laser pulse are extended to describe the interaction of a particle bunch with various realistic laser pulses. We find that the interaction leads to a decrease in average momentum and relative momentum spread. However, the decrease appears to be independent of the length of the pulse and depends only on the energy in the pulse regardless of how it is distributed. Radiation reaction effects occuring during the scattering of an electron by a heavy, highly-charged nucleus are studied. Radiation reaction is seen to affect the particle's motion. We find noticeable differences between the predictions of the Ford-O'Connell and Landau-Lifshitz equations, albeit in regimes where quantum effects would be important.
hep-ph/0011055
Mariano Quiros
M. Carena, J.M. Moreno, M. Quiros, M. Seco and C.E.M. Wagner
Supersymmetric CP-violating Currents and Electroweak Baryogenesis
27 pages, 4 figures, latex2e. Typo corrected and references added
Nucl.Phys.B599:158-184,2001
10.1016/S0550-3213(01)00032-3
LPTENS-00/20, IEM-FT-204/00, IFT-UAM/CSIC-00-31, FERMILAB-PUB-00/240-T, ANL-HEP-PR-00-101, EFI-2000-030
hep-ph
null
In this work we compute the CP-violating currents of the right-handed stops and Higgsinos, induced by the presence of non-trivial vacuum expectation values of the Higgs fields within the context of the minimal supersymmetric extension of the Standard Model (MSSM) with explicit CP-violating phases. Using the Keldysh formalism, we perform the computation of the currents at finite temperature, in an expansion of derivatives of the Higgs fields. Contrary to previous works, we implement a resummation of the Higgs mass insertion effects to all orders in perturbation theory. While the components of the right-handed stop current j^\mu_{\widetilde t_R} become proportional to the difference H_2 \partial^{\mu}H_1-H_1 \partial^{\mu} H_2 (suppressed by \Delta\beta), the Higgsino currents, j^\mu_{\widetilde{H}_i}, present contributions proportional to both H_2 \partial^{\mu}H_1\pm H_1 \partial^{\mu} H_2. For large values of the charged Higgs mass and moderate values of \tan\beta the contribution to the source proportional to H_2 \partial^{\mu}H_1+H_1 \partial^{\mu} H_2 in the diffusion equations become sizeable, although it is suppressed by the Higgsino number violating interaction rate \Gamma_\mu^{-1/2}. For small values of the wall velocity, 0.04\simlt v_\omega \simlt 0.1, the total contribution leads to acceptable values of the baryon asymmetry for values of the CP-violating phases \phi_{CP} in the range 0.04\simlt|\sin\phi_{CP}|\simlt 1. Finally, we comment on the relevance of the latest results of Higgs searches at LEP2 for the mechanism of electroweak baryogenesis within the MSSM.
[ { "created": "Fri, 3 Nov 2000 18:40:21 GMT", "version": "v1" }, { "created": "Tue, 12 Dec 2000 17:25:42 GMT", "version": "v2" } ]
2008-11-26
[ [ "Carena", "M.", "" ], [ "Moreno", "J. M.", "" ], [ "Quiros", "M.", "" ], [ "Seco", "M.", "" ], [ "Wagner", "C. E. M.", "" ] ]
In this work we compute the CP-violating currents of the right-handed stops and Higgsinos, induced by the presence of non-trivial vacuum expectation values of the Higgs fields within the context of the minimal supersymmetric extension of the Standard Model (MSSM) with explicit CP-violating phases. Using the Keldysh formalism, we perform the computation of the currents at finite temperature, in an expansion of derivatives of the Higgs fields. Contrary to previous works, we implement a resummation of the Higgs mass insertion effects to all orders in perturbation theory. While the components of the right-handed stop current j^\mu_{\widetilde t_R} become proportional to the difference H_2 \partial^{\mu}H_1-H_1 \partial^{\mu} H_2 (suppressed by \Delta\beta), the Higgsino currents, j^\mu_{\widetilde{H}_i}, present contributions proportional to both H_2 \partial^{\mu}H_1\pm H_1 \partial^{\mu} H_2. For large values of the charged Higgs mass and moderate values of \tan\beta the contribution to the source proportional to H_2 \partial^{\mu}H_1+H_1 \partial^{\mu} H_2 in the diffusion equations become sizeable, although it is suppressed by the Higgsino number violating interaction rate \Gamma_\mu^{-1/2}. For small values of the wall velocity, 0.04\simlt v_\omega \simlt 0.1, the total contribution leads to acceptable values of the baryon asymmetry for values of the CP-violating phases \phi_{CP} in the range 0.04\simlt|\sin\phi_{CP}|\simlt 1. Finally, we comment on the relevance of the latest results of Higgs searches at LEP2 for the mechanism of electroweak baryogenesis within the MSSM.
2206.03995
Andre Gomes A. H. Gomes
Andr\'e H. Gomes
Constraining GUP Models Using Limits on SME Coefficients
Presented at the Ninth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, May 17-26, 2022
null
null
null
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this proceedings, I outline recent efforts to constrain models based on generalized uncertainty principles (GUP) using limits on coefficients of the Standard-Model Extension. Two main results are reported: (1) bounds on isotropic GUP models are improved by a factor of $10^{10}$ compared to previous spectroscopic bounds; and (2) anisotropic GUP models are established and also constrained.
[ { "created": "Wed, 8 Jun 2022 16:17:50 GMT", "version": "v1" } ]
2022-11-15
[ [ "Gomes", "André H.", "" ] ]
In this proceedings, I outline recent efforts to constrain models based on generalized uncertainty principles (GUP) using limits on coefficients of the Standard-Model Extension. Two main results are reported: (1) bounds on isotropic GUP models are improved by a factor of $10^{10}$ compared to previous spectroscopic bounds; and (2) anisotropic GUP models are established and also constrained.
2101.01305
Laura Reina
Diogenes Figueroa, Seth Quackenbush, Laura Reina, Christian Reuschle
Updates to the One-loop Provider NLOX
8 pages
null
10.1016/j.cpc.2021.108150
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We describe the 1.2 update to NLOX, a computer program for calculations in high-energy particle physics. New features since the 1.0 release and other changes are described, along with usage documentation.
[ { "created": "Tue, 5 Jan 2021 01:28:37 GMT", "version": "v1" } ]
2021-10-04
[ [ "Figueroa", "Diogenes", "" ], [ "Quackenbush", "Seth", "" ], [ "Reina", "Laura", "" ], [ "Reuschle", "Christian", "" ] ]
We describe the 1.2 update to NLOX, a computer program for calculations in high-energy particle physics. New features since the 1.0 release and other changes are described, along with usage documentation.
1711.11554
Benedict V. Harling
Benedict von Harling, Geraldine Servant
QCD-induced Electroweak Phase Transition
33 pages, 5 figures
null
10.1007/JHEP01(2018)159
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Phase transitions associated with nearly conformal dynamics are known to lead to significant supercooling. A notorious example is the phase transition in Randall-Sundrum models or their CFT duals. In fact, it was found that the phase transition in this case is first-order and the tunneling probability for the radion/dilaton is so small that the system typically remains trapped in the false vacuum and the phase transition never completes. The universe then keeps expanding and cooling. Eventually the temperature drops below the QCD scale. We show that the QCD condensates which subsequently form give an additional contribution to the radion/dilaton potential, an effect which had been ignored so far. This significantly reduces the barrier in the potential and allows the phase transition to complete in a substantially larger region of parameter space. Due to the supercooling, electroweak symmetry is then broken simultaneously. This class of models therefore naturally leads to an electroweak phase transition taking place at or below QCD temperatures, with interesting cosmological implications and signatures.
[ { "created": "Thu, 30 Nov 2017 18:20:59 GMT", "version": "v1" } ]
2018-03-14
[ [ "von Harling", "Benedict", "" ], [ "Servant", "Geraldine", "" ] ]
Phase transitions associated with nearly conformal dynamics are known to lead to significant supercooling. A notorious example is the phase transition in Randall-Sundrum models or their CFT duals. In fact, it was found that the phase transition in this case is first-order and the tunneling probability for the radion/dilaton is so small that the system typically remains trapped in the false vacuum and the phase transition never completes. The universe then keeps expanding and cooling. Eventually the temperature drops below the QCD scale. We show that the QCD condensates which subsequently form give an additional contribution to the radion/dilaton potential, an effect which had been ignored so far. This significantly reduces the barrier in the potential and allows the phase transition to complete in a substantially larger region of parameter space. Due to the supercooling, electroweak symmetry is then broken simultaneously. This class of models therefore naturally leads to an electroweak phase transition taking place at or below QCD temperatures, with interesting cosmological implications and signatures.
hep-ph/0007169
Santorelli Pietro
M.A. Ivanov, J.G. Korner, P. Santorelli
The semileptonic decays of the B_c meson
31 pages Latex (uses epsf, revtex). Section II expanded, typos corrected. This version will appear in Phys. Rev. D
Phys.Rev.D63:074010,2001
10.1103/PhysRevD.63.074010
MZ-TH/00-29, DSF-2000/23
hep-ph
null
We study the semileptonic transitions B_c to \eta_c, J/\psi, D, D^*, B, B^*, B_s, B_s^* in the framework of a relativistic constituent quark model. We use experimental data on leptonic J/\psi decay, lattice and QCD sum rule results on leptonic B_c decay, and on radiative \eta_c transitions to adjust the quark model parameters. We compute all form factors of the above semileptonic B_c-transitions and give predictions for various semileptonic B_c decay modes including their \tau-modes when they are kinematically accessible. The implications of heavy quark symmetry for the semileptonic decays are discussed and are shown to be manifest in our explicit relativistic quark model calculation. A comparison of our results with the results of other calculations is performed.
[ { "created": "Mon, 17 Jul 2000 11:32:22 GMT", "version": "v1" }, { "created": "Fri, 22 Dec 2000 15:39:15 GMT", "version": "v2" } ]
2011-03-23
[ [ "Ivanov", "M. A.", "" ], [ "Korner", "J. G.", "" ], [ "Santorelli", "P.", "" ] ]
We study the semileptonic transitions B_c to \eta_c, J/\psi, D, D^*, B, B^*, B_s, B_s^* in the framework of a relativistic constituent quark model. We use experimental data on leptonic J/\psi decay, lattice and QCD sum rule results on leptonic B_c decay, and on radiative \eta_c transitions to adjust the quark model parameters. We compute all form factors of the above semileptonic B_c-transitions and give predictions for various semileptonic B_c decay modes including their \tau-modes when they are kinematically accessible. The implications of heavy quark symmetry for the semileptonic decays are discussed and are shown to be manifest in our explicit relativistic quark model calculation. A comparison of our results with the results of other calculations is performed.
2002.02351
Hanqing Zheng
Yao Ma, Wen-Qi Niu, Yu-Fei Wang, Han-Qing Zheng
How does the $S_{11}$ $N^*(890)$ state emerge from a naive $K$ matrix fit?
9pages, 7 figures
null
10.1088/1572-9494/aba25d
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a pedagogical analysis on $K$ matrix models describing the $\pi N$ scattering amplitude, in $S_{11}$ channel at low energies. We show how the correct use of analyticity in the $s$ channel and crossing symmetry in $t$ and $u$ channels leads to a much improved analytic behavior in the negative $s$ region, in agreement with the prediction from chiral perturbation amplitudes in its validity region. The analysis leads again to the conclusion that a genuine $N^*(890)$ resonance exists.
[ { "created": "Thu, 6 Feb 2020 16:54:28 GMT", "version": "v1" } ]
2020-10-28
[ [ "Ma", "Yao", "" ], [ "Niu", "Wen-Qi", "" ], [ "Wang", "Yu-Fei", "" ], [ "Zheng", "Han-Qing", "" ] ]
We give a pedagogical analysis on $K$ matrix models describing the $\pi N$ scattering amplitude, in $S_{11}$ channel at low energies. We show how the correct use of analyticity in the $s$ channel and crossing symmetry in $t$ and $u$ channels leads to a much improved analytic behavior in the negative $s$ region, in agreement with the prediction from chiral perturbation amplitudes in its validity region. The analysis leads again to the conclusion that a genuine $N^*(890)$ resonance exists.
hep-ph/0309011
Bugra Borasoy
B. Borasoy, R. Nissler
Two-photon decays of pi^0, eta and eta-prime
27 pages, 10 figures
Eur.Phys.J.A19:367-382,2004
10.1140/epja/i2003-10140-1
null
hep-ph nucl-th
null
We investigate the decays of pi^0, eta and eta-prime into two photons in an effective U(3) chiral Lagrangian approach without employing large N_c arguments. Tree level and one-loop contributions from the anomalous Wess-Zumino-Witten Lagrangian are calculated and the importance of eta--eta-prime mixing is discussed. Unitarity corrections beyond one-loop play an important role for the decays with off-shell photons and are included by employing a coupled channel Bethe-Salpeter equation which satisfies unitarity constraints and generates vector-mesons from composed states of two pseudoscalar mesons.
[ { "created": "Mon, 1 Sep 2003 14:57:00 GMT", "version": "v1" }, { "created": "Mon, 20 Oct 2003 13:25:30 GMT", "version": "v2" } ]
2014-11-17
[ [ "Borasoy", "B.", "" ], [ "Nissler", "R.", "" ] ]
We investigate the decays of pi^0, eta and eta-prime into two photons in an effective U(3) chiral Lagrangian approach without employing large N_c arguments. Tree level and one-loop contributions from the anomalous Wess-Zumino-Witten Lagrangian are calculated and the importance of eta--eta-prime mixing is discussed. Unitarity corrections beyond one-loop play an important role for the decays with off-shell photons and are included by employing a coupled channel Bethe-Salpeter equation which satisfies unitarity constraints and generates vector-mesons from composed states of two pseudoscalar mesons.
0811.3778
Ricardo Gon\c{c}alo
R. Goncalo (for the ATLAS and CMS Collaborations)
Standard Model Higgs Searches at the LHC
Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 4 pages, LaTeX, 8 eps figures
null
null
ATL-PHYS-PROC-2008-060
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of the mechanism behind electroweak symmetry breaking is one of the main goals of the Large Hadron Collider and of its general-purpose experiments, ATLAS and CMS. This paper reviews some of the ongoing studies by these collaborations and, when possible, highlights the differences between equivalent channels in both experiments.
[ { "created": "Sun, 23 Nov 2008 22:49:47 GMT", "version": "v1" } ]
2019-08-14
[ [ "Goncalo", "R.", "", "for the ATLAS and CMS Collaborations" ] ]
The study of the mechanism behind electroweak symmetry breaking is one of the main goals of the Large Hadron Collider and of its general-purpose experiments, ATLAS and CMS. This paper reviews some of the ongoing studies by these collaborations and, when possible, highlights the differences between equivalent channels in both experiments.
hep-ph/9608279
null
Keiichi Akama (Saitama Medical College) and Hidezumi Terazawa (INS, University of Tokyo)
Has the Substructure of Quarks Been Found by the Collider Detector at Fermilab?
6 pages, revtex, 4 figures (included)
Phys.Rev.D55:2521-2525,1997
10.1103/PhysRevD.55.2521
INS-Rep.-1154
hep-ph
null
The significant excess recently found by the CDF Collaboration in the inclusive jet cross section for jet transverse energies $E_T \ge 200$ GeV over current QCD predictions can be explained either by possible production of excited bosons (excited gluons, weak bosons, Higgs scalars, etc.) or by that of excited quarks. The masses of the excited boson and the excited quark are estimated to be around 1600 GeV and 500 GeV, respectively.
[ { "created": "Sat, 10 Aug 1996 09:35:46 GMT", "version": "v1" }, { "created": "Thu, 22 Aug 1996 09:30:45 GMT", "version": "v2" }, { "created": "Fri, 23 Aug 1996 07:11:55 GMT", "version": "v3" } ]
2009-12-30
[ [ "Akama", "Keiichi", "", "Saitama Medical College" ], [ "Terazawa", "Hidezumi", "", "INS,\n University of Tokyo" ] ]
The significant excess recently found by the CDF Collaboration in the inclusive jet cross section for jet transverse energies $E_T \ge 200$ GeV over current QCD predictions can be explained either by possible production of excited bosons (excited gluons, weak bosons, Higgs scalars, etc.) or by that of excited quarks. The masses of the excited boson and the excited quark are estimated to be around 1600 GeV and 500 GeV, respectively.
1407.3557
Wojciech Florkowski
Wojciech Florkowski and Radoslaw Ryblewski
Thermalization of anisotropic quark-gluon plasma produced by decays of color flux tubes
Talk presented by WF at Quark Matter 2014
Nucl.Phys. A931 (2014) 34
10.1016/j.nuclphysa.2014.07.040
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Kinetic equations are used to study thermalization of the anisotropic quark-gluon plasma produced by decays of color flux tubes possibly created at the very early stages of relativistic heavy-ion collisions. The decay rates of the initial color tubes are given by the Schwinger formula, while the collision terms are taken in the relaxation-time approximation. By connecting the relaxation time with viscosity we analyze production and thermalization processes in the plasma characterized by different values of the ratio of the shear viscosity to entropy density.
[ { "created": "Mon, 14 Jul 2014 08:11:18 GMT", "version": "v1" } ]
2014-12-12
[ [ "Florkowski", "Wojciech", "" ], [ "Ryblewski", "Radoslaw", "" ] ]
Kinetic equations are used to study thermalization of the anisotropic quark-gluon plasma produced by decays of color flux tubes possibly created at the very early stages of relativistic heavy-ion collisions. The decay rates of the initial color tubes are given by the Schwinger formula, while the collision terms are taken in the relaxation-time approximation. By connecting the relaxation time with viscosity we analyze production and thermalization processes in the plasma characterized by different values of the ratio of the shear viscosity to entropy density.
2310.15137
Andreas S. Kronfeld
Andreas S. Kronfeld
Factorial growth at low orders in perturbative QCD: Control over truncation uncertainties
25 pp + title page, 8 figures; v2 corrects spelling and grammar typos & conforms with published version
null
10.1007/JHEP12(2023)108}
FERMILAB-PUB-23-629-T
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
A method, known as ``minimal renormalon subtraction'' [Phys. Rev. D 97 (2018) 034503, JHEP 2017 (2017) 62], relates the factorial growth of a perturbative series (in QCD) to the power~$p$ of a power correction $\Lambda^p/Q^p$. ($\Lambda$ is the QCD scale, $Q$ some hard scale.) Here, the derivation is simplified and generalized to any~$p$, more than one such correction, and cases with anomalous dimensions. Strikingly, the well-known factorial growth is seen to emerge already at low or medium orders, as a consequence of constraints on the $Q$ dependence from the renormalization group. The effectiveness of the method is studied with the gluonic energy between a static quark and static antiquark (the ``static energy''). Truncation uncertainties are found to be under control after next-to-leading order, despite the small exponent of the power correction ($p=1$) and associated rapid growth seen in the first four coefficients of the perturbative series.
[ { "created": "Mon, 23 Oct 2023 17:44:14 GMT", "version": "v1" }, { "created": "Sun, 14 Jan 2024 23:13:08 GMT", "version": "v2" } ]
2024-01-17
[ [ "Kronfeld", "Andreas S.", "" ] ]
A method, known as ``minimal renormalon subtraction'' [Phys. Rev. D 97 (2018) 034503, JHEP 2017 (2017) 62], relates the factorial growth of a perturbative series (in QCD) to the power~$p$ of a power correction $\Lambda^p/Q^p$. ($\Lambda$ is the QCD scale, $Q$ some hard scale.) Here, the derivation is simplified and generalized to any~$p$, more than one such correction, and cases with anomalous dimensions. Strikingly, the well-known factorial growth is seen to emerge already at low or medium orders, as a consequence of constraints on the $Q$ dependence from the renormalization group. The effectiveness of the method is studied with the gluonic energy between a static quark and static antiquark (the ``static energy''). Truncation uncertainties are found to be under control after next-to-leading order, despite the small exponent of the power correction ($p=1$) and associated rapid growth seen in the first four coefficients of the perturbative series.
hep-ph/9206265
null
Huazhong Zhang
Global Quantization in Gauge Orbit Space with Magnetic Monopoles As a Solution to Strong CP Problem and the Relevance to $U_A(1)$ Problem
LBL-32531 (LaTex 28 pages)
J.Group Theor.Phys. 2 (1994) 55-80
null
null
hep-ph
null
We generalize our discussions and give more general physical applications of a new solution to the strong CP problem with magnetic monopoles as originally proposed by the author$^1$. Especially, we will discuss about the global topological structure in the relevant gauge orbit spaces to be clarified. As it is shown that in non-abelian gauge theories with a $\theta$ term, the induced gauge orbit space with gauge potentials and gauge functions restricted on the space boundary $S^2$ has a magnetic monopole structure and the gauge orbit space has a vortex structure if there is a magnetic monopole in the ordinary space. The Dirac's quantization conditions in the quantum theories ensure that the vacuum angle $\theta$ in the gauge theories must be quantized. The quantization rule is given by $\theta=2\pi/n~(n\neq 0)$ with n being the topological charge of the magnetic monopole. Therefore, the strong CP problem is automatically solved in the presence of a magnetic monopole of charge $\pm 1$ with $\theta=\pm 2\pi$, or magnetic monopoles of very large total topological charge ($|n|\geq 10^92\pi$) if it is consistent with the abundance of magnetic monopoles. Where in the first case with a magnetic monopole of topological charge 1 or -1, we mean the strong CP-violation can be only very small by the measurements implemented so far. Since $\theta=\pm 2\pi$ correspond to different monopole sectors, the CP can not be conserved exactly in strong interactions in this case. In the second case, the strong CP cannot be conserved either for large but finite n. The fact that the strong CP-violation measured so far can be only so small or vanishing may be a signal for the existence of magnetic monopoles. We also conjecture that the parity violation and CP violation in weak interaction fundamentally may intimately
[ { "created": "Tue, 30 Jun 1992 19:19:31 GMT", "version": "v1" }, { "created": "Tue, 18 Aug 1992 20:45:25 GMT", "version": "v2" } ]
2008-02-03
[ [ "Zhang", "Huazhong", "" ] ]
We generalize our discussions and give more general physical applications of a new solution to the strong CP problem with magnetic monopoles as originally proposed by the author$^1$. Especially, we will discuss about the global topological structure in the relevant gauge orbit spaces to be clarified. As it is shown that in non-abelian gauge theories with a $\theta$ term, the induced gauge orbit space with gauge potentials and gauge functions restricted on the space boundary $S^2$ has a magnetic monopole structure and the gauge orbit space has a vortex structure if there is a magnetic monopole in the ordinary space. The Dirac's quantization conditions in the quantum theories ensure that the vacuum angle $\theta$ in the gauge theories must be quantized. The quantization rule is given by $\theta=2\pi/n~(n\neq 0)$ with n being the topological charge of the magnetic monopole. Therefore, the strong CP problem is automatically solved in the presence of a magnetic monopole of charge $\pm 1$ with $\theta=\pm 2\pi$, or magnetic monopoles of very large total topological charge ($|n|\geq 10^92\pi$) if it is consistent with the abundance of magnetic monopoles. Where in the first case with a magnetic monopole of topological charge 1 or -1, we mean the strong CP-violation can be only very small by the measurements implemented so far. Since $\theta=\pm 2\pi$ correspond to different monopole sectors, the CP can not be conserved exactly in strong interactions in this case. In the second case, the strong CP cannot be conserved either for large but finite n. The fact that the strong CP-violation measured so far can be only so small or vanishing may be a signal for the existence of magnetic monopoles. We also conjecture that the parity violation and CP violation in weak interaction fundamentally may intimately
hep-ph/0604205
Kirill Melnikov
Kirill Melnikov
On the QCD corrections to Vainshtein's theorem for VVA correlator
6 pages, 4 figures
Phys.Lett. B639 (2006) 294-298
10.1016/j.physletb.2006.06.031
UH-511-1086-06
hep-ph
null
We point out that, contrary to existing claims of the opposite, Vainshtein's theorem on the non-renormalization of the correlator of an axial and two vector currents, is only valid in the chiral limit. When quarks, that contribute to the correlator, are massive, the QCD corrections do not vanish and the transversal and longitudinal functions are renormalized differently. We compute those corrections and study their implications for QCD effects in electroweak corrections to the muon anomalous magnetic moment.
[ { "created": "Mon, 24 Apr 2006 22:01:30 GMT", "version": "v1" } ]
2009-11-11
[ [ "Melnikov", "Kirill", "" ] ]
We point out that, contrary to existing claims of the opposite, Vainshtein's theorem on the non-renormalization of the correlator of an axial and two vector currents, is only valid in the chiral limit. When quarks, that contribute to the correlator, are massive, the QCD corrections do not vanish and the transversal and longitudinal functions are renormalized differently. We compute those corrections and study their implications for QCD effects in electroweak corrections to the muon anomalous magnetic moment.
0804.3834
Hanqing Zheng
H. Q. Zheng
Dynamical Properties of the $\sigma$ Meson
5 pages, AIP style
AIPConf.Proc.1030:107-111,2008
10.1063/1.2973482
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Studies on the dynamical properties of the $\sigma$ meson are reviewed and discussed. The important role of fundamental principles such as analyticity, unitarity and crossing symmetry played in the studies are stressed.
[ { "created": "Thu, 24 Apr 2008 03:52:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zheng", "H. Q.", "" ] ]
Studies on the dynamical properties of the $\sigma$ meson are reviewed and discussed. The important role of fundamental principles such as analyticity, unitarity and crossing symmetry played in the studies are stressed.
1205.4424
Alexander Jourjine
Alexander N. Jourjine
Unified Lepto-Quark Mixing
7 pages. New references added. Transition from 4 to 3 generations and origin of mixing in bi-spinor SM are made more clear
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a solution to a long standing puzzle about the difference in textures of quark CKM and lepton PMNS mixing matrices by deriving their common representation. We show how the difference in texture of the two matrices arises from assignment of lepton and quark pairs to different representation of a discrete two element symmetry group. The symmetry is absent in the Standard Model. It appears if, instead of Dirac spinors, one describes fermions in terms of bi-spinors and induces essentially unique textures: tri-bimaximal for lepton and O({\lambda}) of Wolfenstein parameterization for quark mixing.
[ { "created": "Sun, 20 May 2012 15:16:01 GMT", "version": "v1" }, { "created": "Tue, 10 Jul 2012 11:37:32 GMT", "version": "v2" }, { "created": "Mon, 10 Sep 2012 10:16:07 GMT", "version": "v3" } ]
2012-09-11
[ [ "Jourjine", "Alexander N.", "" ] ]
We describe a solution to a long standing puzzle about the difference in textures of quark CKM and lepton PMNS mixing matrices by deriving their common representation. We show how the difference in texture of the two matrices arises from assignment of lepton and quark pairs to different representation of a discrete two element symmetry group. The symmetry is absent in the Standard Model. It appears if, instead of Dirac spinors, one describes fermions in terms of bi-spinors and induces essentially unique textures: tri-bimaximal for lepton and O({\lambda}) of Wolfenstein parameterization for quark mixing.
hep-ph/9712228
Robert Harlander
R. Harlander, T. Seidensticker and M. Steinhauser
Complete Corrections of O(\alpha\alpha_s) to the Decay of the Z Boson into Bottom Quarks
Latex, 11 pages, 1 figure included as ps-file. Two references changed. The complete paper is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ttp97/ttp97-52/ or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Phys.Lett. B426 (1998) 125-132
10.1016/S0370-2693(98)00220-2
MPI/PhT/97-81, TTP97-52
hep-ph
null
For the vertex corrections to the partial decay rate $\Gamma(Z \to b\bar{b})$ involving the top quark only the leading terms of order $\alpha\alpha_s$ in the $1/M_t$ expansion are known. In this work we compute the missing next-to-leading corrections. Thus at $O(\alpha\alpha_s)$ the complete corrections to the decay of the Z boson into bottom quarks are at hand.
[ { "created": "Tue, 2 Dec 1997 01:53:59 GMT", "version": "v1" }, { "created": "Mon, 9 Mar 1998 09:48:34 GMT", "version": "v2" } ]
2009-10-30
[ [ "Harlander", "R.", "" ], [ "Seidensticker", "T.", "" ], [ "Steinhauser", "M.", "" ] ]
For the vertex corrections to the partial decay rate $\Gamma(Z \to b\bar{b})$ involving the top quark only the leading terms of order $\alpha\alpha_s$ in the $1/M_t$ expansion are known. In this work we compute the missing next-to-leading corrections. Thus at $O(\alpha\alpha_s)$ the complete corrections to the decay of the Z boson into bottom quarks are at hand.
1105.5397
David Blaschke
D. B. Blaschke, V. V. Dmitriev, G. Roepke and S. A. Smolyansky
BBGKY kinetic approach for an e-e+gamma plasma created from the vacuum in a strong laser-generated electric field: The one-photon annihilation channel
14 pages, 1 figure, one reference with referring text added and one citation corrected
Phys.Rev.D84:085028, 2011
10.1103/PhysRevD.84.085028
null
hep-ph physics.optics physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work a closed system of kinetic equations is obtained from the truncation of the BBGKY hierarchy for the description of the vacuum creation of an electron - positron plasma and secondary photons due to a strong laser field. This truncation is performed in the Markovian approximation for the one-photon annihilation channel which is accessible due to the presence of the strong external field. Estimates of the photon production rate are obtained for different domains of laser field parameters (frequency nu and field strength E). A huge quantity of optical photons of the quasiclassical laser field is necessary to satisfy the conservation laws of energy and momentum of the constituents (e-, e+, gamma) in this channel. Since the number of these optical photons corresponds to the order of perturbation theory, a vanishingly small photon production rate results for the optical region and strongly subcritical fields E << E_c. In the gamma-ray region nu <~ m the required number of laser photons is small and the production rate of photons from the one-photon annihilation process becomes accessible to observations for subcritical fields E <~ E_c. In the infrared region the photon distribution has a 1/k spectrum typical for flicker noise.
[ { "created": "Thu, 26 May 2011 20:22:23 GMT", "version": "v1" }, { "created": "Tue, 31 May 2011 17:03:49 GMT", "version": "v2" } ]
2011-10-26
[ [ "Blaschke", "D. B.", "" ], [ "Dmitriev", "V. V.", "" ], [ "Roepke", "G.", "" ], [ "Smolyansky", "S. A.", "" ] ]
In the present work a closed system of kinetic equations is obtained from the truncation of the BBGKY hierarchy for the description of the vacuum creation of an electron - positron plasma and secondary photons due to a strong laser field. This truncation is performed in the Markovian approximation for the one-photon annihilation channel which is accessible due to the presence of the strong external field. Estimates of the photon production rate are obtained for different domains of laser field parameters (frequency nu and field strength E). A huge quantity of optical photons of the quasiclassical laser field is necessary to satisfy the conservation laws of energy and momentum of the constituents (e-, e+, gamma) in this channel. Since the number of these optical photons corresponds to the order of perturbation theory, a vanishingly small photon production rate results for the optical region and strongly subcritical fields E << E_c. In the gamma-ray region nu <~ m the required number of laser photons is small and the production rate of photons from the one-photon annihilation process becomes accessible to observations for subcritical fields E <~ E_c. In the infrared region the photon distribution has a 1/k spectrum typical for flicker noise.
0805.3910
Andrea Ferroglia
R. Bonciani and A. Ferroglia
Bhabha Scattering at NNLO
To appear in the proceedings of PHIPSI 08, Frascati, Italy, 7-10 April 2008. References added
Nucl.Phys.Proc.Suppl.181-182:259-263,2008
10.1016/j.nuclphysbps.2008.09.047
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the status of the calculation of next-to-next-to-leading order corrections to large angle Bhabha scattering in pure QED. After discussing the electron-loop and photonic corrections, we focus on the recently calculated two-loop virtual corrections involving a heavy-flavor fermion loop. We conclude by assessing the numerical impact of these corrections on the Bhabha scattering cross section at colliders operating at a center of mass energy of about 1-GeV.
[ { "created": "Mon, 26 May 2008 10:31:03 GMT", "version": "v1" }, { "created": "Fri, 11 Jul 2008 14:01:25 GMT", "version": "v2" } ]
2008-11-07
[ [ "Bonciani", "R.", "" ], [ "Ferroglia", "A.", "" ] ]
We review the status of the calculation of next-to-next-to-leading order corrections to large angle Bhabha scattering in pure QED. After discussing the electron-loop and photonic corrections, we focus on the recently calculated two-loop virtual corrections involving a heavy-flavor fermion loop. We conclude by assessing the numerical impact of these corrections on the Bhabha scattering cross section at colliders operating at a center of mass energy of about 1-GeV.
0811.1186
Ashutosh Alok
Ashutosh Kumar Alok, Amol Dighe, Shamayita Ray
CP asymmetry in the decays B --> (X_s, X_d) mu+ mu- with four generations
22 pages, 4 figures; corrected typos, added references
Phys.Rev.D79:034017,2009
10.1103/PhysRevD.79.034017
TIFR/TH/08-42
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We estimate the CP asymmetry A_{CP}(q^2) in the decays B --> X_s mu+ mu- and B --> X_d mu+ mu- in the standard model (SM) with an additional fourth generation. We use a parametrization that allows us to explore the complete parameter space of the 4X4 quark mixing matrix, and constrain these parameters from the current data on B decays. We find that the enhancement in A_{CP}(q^2) depends strongly on the mass of the t', the up-type quark in the fourth generation. For m_t' around 400 GeV, the CP asymmetry in the high-q^2 region (q^2 > 14.4 GeV^2) can be enhanced by more than an order of magnitude for B --> X_s mu+ mu- and up to a factor of 6 for B --> X_d mu+ mu-. There is no enhancement in the low-q^2 region (1< q^2 <6 GeV^2). With increasing m_t', the A_{CP}(q^2) in the high-q^2 (low-q^2) region first decreases (increases) and then saturates at a value a few times the SM prediction. In the high-q^2 region of B --> X_s mu+ mu-, this saturation value may be up to 25 times the SM expectation.
[ { "created": "Fri, 7 Nov 2008 17:26:32 GMT", "version": "v1" }, { "created": "Wed, 4 Feb 2009 12:20:56 GMT", "version": "v2" } ]
2010-02-08
[ [ "Alok", "Ashutosh Kumar", "" ], [ "Dighe", "Amol", "" ], [ "Ray", "Shamayita", "" ] ]
We estimate the CP asymmetry A_{CP}(q^2) in the decays B --> X_s mu+ mu- and B --> X_d mu+ mu- in the standard model (SM) with an additional fourth generation. We use a parametrization that allows us to explore the complete parameter space of the 4X4 quark mixing matrix, and constrain these parameters from the current data on B decays. We find that the enhancement in A_{CP}(q^2) depends strongly on the mass of the t', the up-type quark in the fourth generation. For m_t' around 400 GeV, the CP asymmetry in the high-q^2 region (q^2 > 14.4 GeV^2) can be enhanced by more than an order of magnitude for B --> X_s mu+ mu- and up to a factor of 6 for B --> X_d mu+ mu-. There is no enhancement in the low-q^2 region (1< q^2 <6 GeV^2). With increasing m_t', the A_{CP}(q^2) in the high-q^2 (low-q^2) region first decreases (increases) and then saturates at a value a few times the SM prediction. In the high-q^2 region of B --> X_s mu+ mu-, this saturation value may be up to 25 times the SM expectation.
2202.09371
Adrian Carmona
Adrian Carmona, Fatemeh Elahi, Christiane Scherb, Pedro Schwaller
The ALPs from the Top: Searching for long lived axion-like particles from exotic top decays
v2: matches published version; 18 pages, 7 figures, 2 tables
null
10.1007/JHEP07(2022)122
MITP/22-017
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We propose a search for long lived axion-like particles (ALPs) in exotic top decays. Flavour-violating ALPs appear as low energy effective theories for various new physics scenarios such as t-channel dark sectors or Froggatt-Nielsen models. In this case the top quark may decay to an ALP and an up- or charm-quark. For masses in the few GeV range, the ALP is long lived across most of the viable parameter space, suggesting a dedicated search. We propose to search for these long lived ALPs in $t\bar{t}$ events, using one top quark as a trigger. We focus on ALPs decaying in the hadronic calorimeter, and show that the ratio of energy deposits in the electromagnetic and hadronic calorimeters as well as track vetoes can efficiently suppress Standard Model backgrounds. Our proposed search can probe exotic top branching ratios smaller than $10^{-4}$ with a conservative strategy at the upcoming LHC run, and potentially below the $10^{-7}$ level with more advanced methods. Finally we also show that measurements of single top production probe these branching ratios in the very short and very long lifetime limit at the $10^{-3}$ level.
[ { "created": "Fri, 18 Feb 2022 19:00:01 GMT", "version": "v1" }, { "created": "Thu, 20 Oct 2022 14:57:33 GMT", "version": "v2" } ]
2022-10-21
[ [ "Carmona", "Adrian", "" ], [ "Elahi", "Fatemeh", "" ], [ "Scherb", "Christiane", "" ], [ "Schwaller", "Pedro", "" ] ]
We propose a search for long lived axion-like particles (ALPs) in exotic top decays. Flavour-violating ALPs appear as low energy effective theories for various new physics scenarios such as t-channel dark sectors or Froggatt-Nielsen models. In this case the top quark may decay to an ALP and an up- or charm-quark. For masses in the few GeV range, the ALP is long lived across most of the viable parameter space, suggesting a dedicated search. We propose to search for these long lived ALPs in $t\bar{t}$ events, using one top quark as a trigger. We focus on ALPs decaying in the hadronic calorimeter, and show that the ratio of energy deposits in the electromagnetic and hadronic calorimeters as well as track vetoes can efficiently suppress Standard Model backgrounds. Our proposed search can probe exotic top branching ratios smaller than $10^{-4}$ with a conservative strategy at the upcoming LHC run, and potentially below the $10^{-7}$ level with more advanced methods. Finally we also show that measurements of single top production probe these branching ratios in the very short and very long lifetime limit at the $10^{-3}$ level.
1712.04754
Jean-Nicolas Lang
Ansgar Denner, Jean-Nicolas Lang, Sandro Uccirati
Recola2: a one-loop matrix-element generator for BSM theories and SM effective field theory
6 pages, contribution to the proceedings of the 13th International Symposium on Radiative Corrections (RADCOR 2017)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the Recola2 library for the efficient generation and computation of one-loop amplitudes in Beyond-Standard-Model theories. Recola2 is based on Recola, an efficient one-loop amplitude generator for the Standard Model, and Rept1l, a newly developed tool to generate one-loop model files for Recola2 in a fully automated way. Recola2 is able to operate with non-trivial extensions of the SM, e.g. extended Higgs sectors and effective field theories. We discuss first applications to extended Higgs sectors and their renormalization.
[ { "created": "Wed, 13 Dec 2017 13:33:47 GMT", "version": "v1" } ]
2017-12-14
[ [ "Denner", "Ansgar", "" ], [ "Lang", "Jean-Nicolas", "" ], [ "Uccirati", "Sandro", "" ] ]
We present the Recola2 library for the efficient generation and computation of one-loop amplitudes in Beyond-Standard-Model theories. Recola2 is based on Recola, an efficient one-loop amplitude generator for the Standard Model, and Rept1l, a newly developed tool to generate one-loop model files for Recola2 in a fully automated way. Recola2 is able to operate with non-trivial extensions of the SM, e.g. extended Higgs sectors and effective field theories. We discuss first applications to extended Higgs sectors and their renormalization.
2311.08203
Zoltan Peli
Zolt\'an P\'eli
Precise prediction for the W boson mass in U(1) extensions of the standard model
Contribution to Matter To The Deepest: Recent Developments In Physics Of Fundamental Interactions XLV International Conference of Theoretical Physics, 2023
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present the one-loop correction to the $W$ boson mass in U(1)$_z$ type extensions of the standard model. We compare it to an approximation, often used in high energy physics tools. We point out that if the $Z'$ boson -- predicted in U(1)$_z$ type extensions -- is much heavier than the $Z$ boson, then the use of the complete set of one-loop corrections is necessary.
[ { "created": "Tue, 14 Nov 2023 14:39:05 GMT", "version": "v1" } ]
2023-11-15
[ [ "Péli", "Zoltán", "" ] ]
We present the one-loop correction to the $W$ boson mass in U(1)$_z$ type extensions of the standard model. We compare it to an approximation, often used in high energy physics tools. We point out that if the $Z'$ boson -- predicted in U(1)$_z$ type extensions -- is much heavier than the $Z$ boson, then the use of the complete set of one-loop corrections is necessary.
1906.00612
Tanmoy Mondal
Eung Jin Chun, Jongkuk Kim and Tanmoy Mondal
Electron EDM and Muon anomalous magnetic moment in Two-Higgs-Doublet Models
16 pages, 3 figures
null
10.1007/JHEP12(2019)068
KIAS-P19032
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CP violating two-Higgs doublet model of type-X may enhance significantly the electric and magnetic moment of leptons through two-loop Barr-Zee diagrams. We analyze the general parameter space of the type-X 2HDM consistent with the muon $g-2$ and the electron EDM measurements to show how strongly the CP violating parameter is constrained in the region explaining the muon $ g-2$ anomaly.
[ { "created": "Mon, 3 Jun 2019 07:34:39 GMT", "version": "v1" } ]
2020-01-29
[ [ "Chun", "Eung Jin", "" ], [ "Kim", "Jongkuk", "" ], [ "Mondal", "Tanmoy", "" ] ]
The CP violating two-Higgs doublet model of type-X may enhance significantly the electric and magnetic moment of leptons through two-loop Barr-Zee diagrams. We analyze the general parameter space of the type-X 2HDM consistent with the muon $g-2$ and the electron EDM measurements to show how strongly the CP violating parameter is constrained in the region explaining the muon $ g-2$ anomaly.
hep-ph/9910368
Yakov Azimov
Ya.I. Azimov (PNPI, St.Petersburg, Russia)
Neutral kaons as instrument for studying heavier flavors
LATEX, 4 pages, no figures. Misprint is corrected. To be published in Proceedings of the XIth Rencontres de Blois, June 27-July 3, 1999, Blois, France
null
null
null
hep-ph hep-ex
null
Strangeness oscillations in decays of neutral kaons are suggested to be used as an analyzer to investigate detailed properties of heavy flavor hadrons and their decays. Here we briefly explain why, where, and to what problems this approach may be applied.
[ { "created": "Sat, 16 Oct 1999 07:49:50 GMT", "version": "v1" }, { "created": "Tue, 19 Oct 1999 16:33:46 GMT", "version": "v2" } ]
2007-05-23
[ [ "Azimov", "Ya. I.", "", "PNPI, St.Petersburg, Russia" ] ]
Strangeness oscillations in decays of neutral kaons are suggested to be used as an analyzer to investigate detailed properties of heavy flavor hadrons and their decays. Here we briefly explain why, where, and to what problems this approach may be applied.
2108.12700
Salman Ahamad Khan
Salman Ahamad Khan, Mujeeb Hasan and Binoy Krishna Patra
Heavy quarkonia in a baryon asymmetric strongly magnetized hot quark matter
29 pages, 12 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recently there is a resurrection in the study of heavy quark bound states in a hot and baryonless matter with an ambient magnetic field but the matter produced at heavy-ion collider experiments is not perfectly baryonless, so we wish to explore the effect of small baryon asymmetry on the properties of heavy quarkonia immersed in a strongly magnetized hot quark matter. Therefore, we have first revisited the structure of gluon self-energy tensor in the above environment to compute the resummed propagator for gluons. This resummed propagator embodies the properties of medium, which gets translated into the (complex) potential between $Q$ and $\bar Q$ placed in the medium. We observe that the baryon asymmetry makes the real-part of potential slightly more attractive and weakens the imaginary-part. This opposing effects thus lead to the enhancement of binding energies and the reduction of thermal widths of $Q \bar Q$ ground states, respectively. Finally, the properties of quarkonia thus deciphered facilitates to compute the dissociation points of $J/\psi$ and $\Upsilon$, which are found to have slightly larger values in the presence of baryon asymmetry. For example, $J/\psi$ is dissociated at $1.64~T_c$, $1.69~T_c$, and $1.75~T_c$, whereas $\Upsilon$ is dissociated at $1.95~T_c$, $1.97~T_c$ and $2.00 ~T_c$, for $\mu=0, 60$ and $ 100 $ MeV, respectively. This observation prevents early dissociation of quarkonia in the matter produced at ultrarelativistic heavy ion collisions with a small net baryon number, compared to the ideal baryonless matter.
[ { "created": "Sat, 28 Aug 2021 19:42:55 GMT", "version": "v1" }, { "created": "Sat, 18 Mar 2023 11:03:17 GMT", "version": "v2" } ]
2023-03-21
[ [ "Khan", "Salman Ahamad", "" ], [ "Hasan", "Mujeeb", "" ], [ "Patra", "Binoy Krishna", "" ] ]
Recently there is a resurrection in the study of heavy quark bound states in a hot and baryonless matter with an ambient magnetic field but the matter produced at heavy-ion collider experiments is not perfectly baryonless, so we wish to explore the effect of small baryon asymmetry on the properties of heavy quarkonia immersed in a strongly magnetized hot quark matter. Therefore, we have first revisited the structure of gluon self-energy tensor in the above environment to compute the resummed propagator for gluons. This resummed propagator embodies the properties of medium, which gets translated into the (complex) potential between $Q$ and $\bar Q$ placed in the medium. We observe that the baryon asymmetry makes the real-part of potential slightly more attractive and weakens the imaginary-part. This opposing effects thus lead to the enhancement of binding energies and the reduction of thermal widths of $Q \bar Q$ ground states, respectively. Finally, the properties of quarkonia thus deciphered facilitates to compute the dissociation points of $J/\psi$ and $\Upsilon$, which are found to have slightly larger values in the presence of baryon asymmetry. For example, $J/\psi$ is dissociated at $1.64~T_c$, $1.69~T_c$, and $1.75~T_c$, whereas $\Upsilon$ is dissociated at $1.95~T_c$, $1.97~T_c$ and $2.00 ~T_c$, for $\mu=0, 60$ and $ 100 $ MeV, respectively. This observation prevents early dissociation of quarkonia in the matter produced at ultrarelativistic heavy ion collisions with a small net baryon number, compared to the ideal baryonless matter.
1902.07236
Mehmet Demirci Dr.
M. Demirci
Pseudoscalar Higgs boson pair production at a photon-photon collision in the two Higgs doublet model
11 pages, 7 figures, 4 tables
Turk. J Phys. 43(5), 442-458 (2019)
10.3906/fiz-1903-15
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, the direct pair production of the pseudoscalar Higgs boson at a photon-photon collision is analyzed in the context of two Higgs doublet model, taking account the complete one-loop contributions. In order to illustrate the effect of the new physics, four benchmark points scenarios, which are consistent with theoretical and current experimental constraints, are chosen in the type-I of THDM with an exact alignment limit. In these benchmark points, the CP even lightest Higgs boson ($h^0$) have the Standard Model like couplings to the gauge bosons. The effect of individual contributions from each type of one-loop diagrams on the total cross section are examined in detail. The dependence of total cross section on the center-of-mass energy is also presented at the various polarization configurations of the incoming photons. Moreover, the regions $m_{12}^2-\tan\beta$ and $m_A-\tan\beta$ in the parameter space of the THDM are scanned for some fixed values of other parameters. The box-type diagrams make a much larger contribution to the total cross section than the others at high energies. Total cross section can be enhanced by a two factor thanks to opposite polarized photons as well as threshold effects.
[ { "created": "Tue, 19 Feb 2019 19:11:59 GMT", "version": "v1" } ]
2019-10-22
[ [ "Demirci", "M.", "" ] ]
In this study, the direct pair production of the pseudoscalar Higgs boson at a photon-photon collision is analyzed in the context of two Higgs doublet model, taking account the complete one-loop contributions. In order to illustrate the effect of the new physics, four benchmark points scenarios, which are consistent with theoretical and current experimental constraints, are chosen in the type-I of THDM with an exact alignment limit. In these benchmark points, the CP even lightest Higgs boson ($h^0$) have the Standard Model like couplings to the gauge bosons. The effect of individual contributions from each type of one-loop diagrams on the total cross section are examined in detail. The dependence of total cross section on the center-of-mass energy is also presented at the various polarization configurations of the incoming photons. Moreover, the regions $m_{12}^2-\tan\beta$ and $m_A-\tan\beta$ in the parameter space of the THDM are scanned for some fixed values of other parameters. The box-type diagrams make a much larger contribution to the total cross section than the others at high energies. Total cross section can be enhanced by a two factor thanks to opposite polarized photons as well as threshold effects.