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hep-ph/0112174
Kazuhiro Tanaka
Hiroyuki Kawamura (1), Jiro Kodaira (2), Cong-Feng Qiao (2), Kazuhiro Tanaka (3) ((1) DESY, (2) Hiroshima Univ., (3) Juntendo Univ.)
Transverse Momentum Distribution in the B Mesons in the Heavy-quark Limit: the Wandzura-Wilczek Part
7 pages LaTeX. Discussion about the difference between the Wandzura-Wilczek approximation and the full result for the first moment is added in the final part. Minor corrections in the other part. Some footnotes and Refs are added
Mod.Phys.Lett. A18 (2003) 799
10.1142/S021773230300985X
DESY 01-212, HUPD-0116, JUPD-0123
hep-ph
null
In the heavy-quark limit, the valence Fock-state components in the B mesons are described by a set of two light-cone wavefunctions. We show that these two wavefunctions obey simple coupled differential equations, which are based on the equations of motion in the Heavy Quark Effective Theory (HQET), and the analytic solutions for them are obtained. The results generalize the recently obtained longitudinal-momentum distribution in the Wandzura-Wilczek approximation by including the transverse momenta. We find that the transverse momentum distribution depends on the longitudinal momentum of the constituents, and that the wavefunctions damp very slowly for large transverse separation between quark and antiquark.
[ { "created": "Thu, 13 Dec 2001 08:39:51 GMT", "version": "v1" }, { "created": "Mon, 18 Nov 2002 13:31:40 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kawamura", "Hiroyuki", "", "DESY" ], [ "Kodaira", "Jiro", "", "Hiroshima Univ" ], [ "Qiao", "Cong-Feng", "", "Hiroshima Univ" ], [ "Tanaka", "Kazuhiro", "", "Juntendo Univ" ] ]
In the heavy-quark limit, the valence Fock-state components in the B mesons are described by a set of two light-cone wavefunctions. We show that these two wavefunctions obey simple coupled differential equations, which are based on the equations of motion in the Heavy Quark Effective Theory (HQET), and the analytic solutions for them are obtained. The results generalize the recently obtained longitudinal-momentum distribution in the Wandzura-Wilczek approximation by including the transverse momenta. We find that the transverse momentum distribution depends on the longitudinal momentum of the constituents, and that the wavefunctions damp very slowly for large transverse separation between quark and antiquark.
hep-ph/9505202
R. Sekhar Chivukula
R. Sekhar Chivukula
Strong W_L W_L Scattering
Latex file using [aps,aipbook,floats,epsf]{revtex}. 11pages, 7 Postscript figures. Full PS copy at http://smyrd.bu.edu/htfigs/htfigs.html . Talk presented at the International Symposium on Vector Boson Self-Interactions, UCLA, Feb. 1-3, 1995
null
10.1063/1.49308
BUHEP-95-17
hep-ph
null
I describe theories of a strongly-interacting electroweak symmetry breaking sector and discuss the expected size of anomalous weak-boson couplings in these models.
[ { "created": "Mon, 1 May 1995 14:11:10 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chivukula", "R. Sekhar", "" ] ]
I describe theories of a strongly-interacting electroweak symmetry breaking sector and discuss the expected size of anomalous weak-boson couplings in these models.
2007.11813
Asli Abdullahi
Asli Abdullahi, Matheus Hostert, Silvia Pascoli
A Dark Seesaw Solution to Low Energy Anomalies: MiniBooNE, the muon $(g-2)$, and BaBar
v2: Discussion extended, KOTO explanation removed and benchmark points updated. Otherwise, conclusions unchanged. 18 pages, 2 figures, 5 tables. v3: Typos fixed. Accepted for publication in Physics Letters B
Phys.Lett.B 820 (2021) 136531
10.1016/j.physletb.2021.136531
FTPI-MINN-20-25, FTPI-MINN-20-25, IPPP/20/32
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent update from MiniBooNE has strengthened the observed $4.8\sigma$ excess of $e$-like events. Motivated by this and other notable deviations from standard model predictions, such as the muon $(g-2)$, we propose a solution to low energy anomalies through a dark neutrino sector. The model is renormalizable and can also explain light neutrino masses with an anomaly-free and dark $U(1)^\prime$ gauge symmetry broken at the GeV scale. Large kinetic mixing leads to s-channel production of heavy neutral leptons at $e^+e^-$ colliders, where we point out and explain a $\gtrsim 2\sigma$ excess observed in the BaBar monophoton data. Our model is also compatible with anomalous $e$-like events seen at old accelerator experiments, as well as with an excess of double vertex signatures observed at CCFR.
[ { "created": "Thu, 23 Jul 2020 06:18:38 GMT", "version": "v1" }, { "created": "Tue, 18 Aug 2020 10:20:01 GMT", "version": "v2" }, { "created": "Sat, 31 Jul 2021 17:46:10 GMT", "version": "v3" } ]
2021-08-03
[ [ "Abdullahi", "Asli", "" ], [ "Hostert", "Matheus", "" ], [ "Pascoli", "Silvia", "" ] ]
A recent update from MiniBooNE has strengthened the observed $4.8\sigma$ excess of $e$-like events. Motivated by this and other notable deviations from standard model predictions, such as the muon $(g-2)$, we propose a solution to low energy anomalies through a dark neutrino sector. The model is renormalizable and can also explain light neutrino masses with an anomaly-free and dark $U(1)^\prime$ gauge symmetry broken at the GeV scale. Large kinetic mixing leads to s-channel production of heavy neutral leptons at $e^+e^-$ colliders, where we point out and explain a $\gtrsim 2\sigma$ excess observed in the BaBar monophoton data. Our model is also compatible with anomalous $e$-like events seen at old accelerator experiments, as well as with an excess of double vertex signatures observed at CCFR.
0709.3913
Pedro Brogueira
P. Brogueira, J. Dias de Deus and J. G. Milhano
Forward-Backward rapidity correlations at all rapidities
6 pages, 3 figures
Phys.Rev.C76:064901,2007
10.1103/PhysRevC.76.064901
null
hep-ph
null
We discuss forward-bacward rapidity correlations in the general situation of asymmetrical collisions, asymmetric rapidity windows, higher rapidities and higher energy. We give predictions for RHIC and LHC.
[ { "created": "Tue, 25 Sep 2007 10:38:52 GMT", "version": "v1" }, { "created": "Wed, 26 Sep 2007 13:17:31 GMT", "version": "v2" }, { "created": "Fri, 28 Sep 2007 15:02:42 GMT", "version": "v3" } ]
2008-11-26
[ [ "Brogueira", "P.", "" ], [ "de Deus", "J. Dias", "" ], [ "Milhano", "J. G.", "" ] ]
We discuss forward-bacward rapidity correlations in the general situation of asymmetrical collisions, asymmetric rapidity windows, higher rapidities and higher energy. We give predictions for RHIC and LHC.
hep-ph/9510208
Kingman Cheung
Kingman Cheung and Tzu Chiang Yuan
Heavy Quark Fragmentation Functions for D-wave Quarkonium and Charmed Beauty Mesons
26 pages in RevteX and 3 figures in postscript. Also available at http://www.ph.utexas.edu/~cheung/paper.html
Phys.Rev. D53 (1996) 3591-3603
10.1103/PhysRevD.53.3591
CPP-95-13, UCD-95-24
hep-ph
null
At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and $\bar bc$ mesons in high energy $e^+e^-$ and hadronic collisions is dominated by parton fragmentation. We calculate the heavy quark fragmentation functions into the D-wave quarkonium and $\bar bc$ mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In the $\bar b c$ meson case, one set of its D-wave states is expected to lie below the open flavor threshold. The total fragmentation probability for a $\bar b$ antiquark to split into the D-wave $\bar b c$ mesons is about $2 \times 10^{-5}$, which implies that only 2\% of the total pseudo-scalar ground state $B_c$ comes from the cascades of these orbitally excited states.
[ { "created": "Mon, 2 Oct 1995 20:04:59 GMT", "version": "v1" } ]
2009-10-28
[ [ "Cheung", "Kingman", "" ], [ "Yuan", "Tzu Chiang", "" ] ]
At the large transverse momentum region, the production of heavy-heavy bound-states such as charmonium, bottomonium, and $\bar bc$ mesons in high energy $e^+e^-$ and hadronic collisions is dominated by parton fragmentation. We calculate the heavy quark fragmentation functions into the D-wave quarkonium and $\bar bc$ mesons to leading order in the strong coupling constant and in the non-relativistic expansion. In the $\bar b c$ meson case, one set of its D-wave states is expected to lie below the open flavor threshold. The total fragmentation probability for a $\bar b$ antiquark to split into the D-wave $\bar b c$ mesons is about $2 \times 10^{-5}$, which implies that only 2\% of the total pseudo-scalar ground state $B_c$ comes from the cascades of these orbitally excited states.
0807.0795
Alakabha Datta
Alakabha Datta
Suppressed FCNC in New Physics with Shared Flavor Symmetry
20 pages, no figures
Phys.Rev.D78:095004,2008
10.1103/PhysRevD.78.095004
UMISS-HEP-2008-04
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many extensions of the Standard Model(SM) generate contributions to Flavor Changing Neutral Current(FCNC) processes that must have sufficient flavor suppression to be consistent with experiments, if the new physics (NP) is associated with a scale of a TeV. Here we present a mechanism for suppressing the NP effects to FCNC processes. We consider the possibility that the source of NP contributions to FCNC processes share the same flavor symmetry underlying the SM source of FCNC processes which are the quark and lepton mass matrices. We call this the principle of shared flavor symmetry. In the flavor symmetric limit, the quark and lepton mixing matrices have fixed forms and there are no NP FCNC processes. In the flavor symmetric limit, we take the quark mixing matrix to be the identity matrix and the lepton mixing matrix to be given by tri-bimaximal mixing. Realistic mixing matrices are obtained by the small breaking of the flavor symmetry. New contributions to FCNC processes arise because of non universal breaking of the flavor symmetry in the quark and lepton mass matrices and the NP sources of FCNC processes. In particular, we will focus on new FCNC effects that arise due to the breaking of flavor symmetry only in the quark and charged lepton mass matrices but not in the NP sector. In this scenario, NP contributions to FCNC processes is linked to the source of flavor symmetry breaking in the quark and charged lepton mass matrices. To demonstrate the mechanism we use a two higgs doublet model as an example of beyond the SM physics though one should be able to adapt this mechanism to other models of new physics.
[ { "created": "Fri, 4 Jul 2008 17:00:31 GMT", "version": "v1" } ]
2008-12-18
[ [ "Datta", "Alakabha", "" ] ]
Many extensions of the Standard Model(SM) generate contributions to Flavor Changing Neutral Current(FCNC) processes that must have sufficient flavor suppression to be consistent with experiments, if the new physics (NP) is associated with a scale of a TeV. Here we present a mechanism for suppressing the NP effects to FCNC processes. We consider the possibility that the source of NP contributions to FCNC processes share the same flavor symmetry underlying the SM source of FCNC processes which are the quark and lepton mass matrices. We call this the principle of shared flavor symmetry. In the flavor symmetric limit, the quark and lepton mixing matrices have fixed forms and there are no NP FCNC processes. In the flavor symmetric limit, we take the quark mixing matrix to be the identity matrix and the lepton mixing matrix to be given by tri-bimaximal mixing. Realistic mixing matrices are obtained by the small breaking of the flavor symmetry. New contributions to FCNC processes arise because of non universal breaking of the flavor symmetry in the quark and lepton mass matrices and the NP sources of FCNC processes. In particular, we will focus on new FCNC effects that arise due to the breaking of flavor symmetry only in the quark and charged lepton mass matrices but not in the NP sector. In this scenario, NP contributions to FCNC processes is linked to the source of flavor symmetry breaking in the quark and charged lepton mass matrices. To demonstrate the mechanism we use a two higgs doublet model as an example of beyond the SM physics though one should be able to adapt this mechanism to other models of new physics.
hep-ph/0307368
Chris Korthals Altes
C.P. Korthals Altes
Cosmological constraints from extra-dimension induced domain walls
8 pages, 3 figures; prepared for IVth Marseille International Cosmology Conference
null
null
null
hep-ph
null
TeV size extra dimensions introduce domain walls. Such walls are inconsistent with CMB anisotropies. Either inflationary dynamics washes them out, or the reheating temperature is lower then the temperature at which the walls start forming networks. As the restoration of the symmetry is non-perturbative we have performed 5d lattice simulations which show the occurrence of a cut-off in the fifth dimension as well as symmetry restoration.
[ { "created": "Wed, 30 Jul 2003 15:22:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Altes", "C. P. Korthals", "" ] ]
TeV size extra dimensions introduce domain walls. Such walls are inconsistent with CMB anisotropies. Either inflationary dynamics washes them out, or the reheating temperature is lower then the temperature at which the walls start forming networks. As the restoration of the symmetry is non-perturbative we have performed 5d lattice simulations which show the occurrence of a cut-off in the fifth dimension as well as symmetry restoration.
2103.14234
Wen Yin
Wen Yin
Radiative lepton mass and muon $g-2$ with suppressed lepton flavor and CP violations
13 pages, 1 figure v2: references added, g-2 value updated by including the Fermilab result
null
10.1007/JHEP08(2021)043
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent experimental status, including the confirmation of the muon $g-2$ anomaly at Fermilab, indicates a Beyond Standard Model (BSM) satisfying the following properties: 1) it enhances the $g-2$ 2) suppresses flavor violations, such as $\mu \to e \gamma$, 3) suppresses CP violations, such as the electron electric dipole moment (EDM). In this letter, I show that if the masses of heavy leptons are generated radiatively, the eigenbasis of the mass matrix and higher dimensional photon operators can be automatically aligned. As a result, the muon $g-2$ is enhanced but the EDM of the electron and $\mu \to e \gamma$ rate are suppressed. Phenomenology and applications of the mechanism to the B-physics anomalies are argued.
[ { "created": "Fri, 26 Mar 2021 02:44:17 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2021 17:09:24 GMT", "version": "v2" } ]
2021-09-01
[ [ "Yin", "Wen", "" ] ]
The recent experimental status, including the confirmation of the muon $g-2$ anomaly at Fermilab, indicates a Beyond Standard Model (BSM) satisfying the following properties: 1) it enhances the $g-2$ 2) suppresses flavor violations, such as $\mu \to e \gamma$, 3) suppresses CP violations, such as the electron electric dipole moment (EDM). In this letter, I show that if the masses of heavy leptons are generated radiatively, the eigenbasis of the mass matrix and higher dimensional photon operators can be automatically aligned. As a result, the muon $g-2$ is enhanced but the EDM of the electron and $\mu \to e \gamma$ rate are suppressed. Phenomenology and applications of the mechanism to the B-physics anomalies are argued.
1709.01549
Marcos A. Garcia Garcia
Marcos A. G. Garcia, Yann Mambrini, Keith A. Olive, Marco Peloso
Enhancement of the Dark Matter Abundance Before Reheating: Applications to Gravitino Dark Matter
16 pages, 5 figures
Phys. Rev. D 96, 103510 (2017)
10.1103/PhysRevD.96.103510
LPT--Orsay 17-36, UMN--TH--3635/17, FTPI--MINN--17/15
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the first stages of inflationary reheating, the temperature of the radiation produced by inflaton decays is typically higher than the commonly defined reheating temperature $T_{RH} \sim (\Gamma_\phi M_P)^{1/2}$ where $\Gamma_\phi$ is the inflaton decay rate. We consider the effect of particle production at temperatures at or near the maximum temperature attained during reheating. We show that the impact of this early production on the final particle abundance depends strongly on the temperature dependence of the production cross section. For $\langle \sigma v \rangle \sim T^n/M^{n+2}$, and for $n < 6$, any particle produced at $T_{\rm max}$ is diluted by the later generation of entropy near $T_{RH}$. This applies to cases such as gravitino production in low scale supersymmetric models ($n=0$) or NETDM models of dark matter ($n=2$). However, for $n\ge6$ the net abundance of particles produced during reheating is enhanced by over an order of magnitude, dominating over the dilution effect. This applies, for instance to gravitino production in high scale supersymmetry models where $n=6$.
[ { "created": "Tue, 5 Sep 2017 18:39:54 GMT", "version": "v1" } ]
2017-11-22
[ [ "Garcia", "Marcos A. G.", "" ], [ "Mambrini", "Yann", "" ], [ "Olive", "Keith A.", "" ], [ "Peloso", "Marco", "" ] ]
In the first stages of inflationary reheating, the temperature of the radiation produced by inflaton decays is typically higher than the commonly defined reheating temperature $T_{RH} \sim (\Gamma_\phi M_P)^{1/2}$ where $\Gamma_\phi$ is the inflaton decay rate. We consider the effect of particle production at temperatures at or near the maximum temperature attained during reheating. We show that the impact of this early production on the final particle abundance depends strongly on the temperature dependence of the production cross section. For $\langle \sigma v \rangle \sim T^n/M^{n+2}$, and for $n < 6$, any particle produced at $T_{\rm max}$ is diluted by the later generation of entropy near $T_{RH}$. This applies to cases such as gravitino production in low scale supersymmetric models ($n=0$) or NETDM models of dark matter ($n=2$). However, for $n\ge6$ the net abundance of particles produced during reheating is enhanced by over an order of magnitude, dominating over the dilution effect. This applies, for instance to gravitino production in high scale supersymmetry models where $n=6$.
hep-ph/9912251
Carlo Oleari
C. Anastasiou, E.W.N. Glover and C. Oleari
The two-loop scalar and tensor pentabox graph with light-like legs
Detailed expansions of intermediate results added
Nucl.Phys.B575:416-436,2000; Erratum-ibid.B585:763-770,2000
10.1016/S0550-3213(00)00079-1
DTP/99/106
hep-ph
null
We study the scalar and tensor integrals associated with the pentabox topology: the class of two-loop box integrals with seven propagators - five in one loop and three in the other. We focus on the case where the external legs are light-like and use integration-by-parts identities to express the scalar integral in terms of two master-topology integrals and present an explicit analytic expression for the pentabox scalar integral as a series expansion in ep = (4-D)/2. We also give an algorithm based on integration by parts for relating the generic tensor integrals to the same two master integrals and provide general formulae describing the master integrals in arbitrary dimension and with general powers of propagators.
[ { "created": "Mon, 6 Dec 1999 18:07:05 GMT", "version": "v1" }, { "created": "Tue, 11 Jan 2000 21:30:19 GMT", "version": "v2" }, { "created": "Tue, 21 Mar 2000 13:46:54 GMT", "version": "v3" } ]
2008-11-26
[ [ "Anastasiou", "C.", "" ], [ "Glover", "E. W. N.", "" ], [ "Oleari", "C.", "" ] ]
We study the scalar and tensor integrals associated with the pentabox topology: the class of two-loop box integrals with seven propagators - five in one loop and three in the other. We focus on the case where the external legs are light-like and use integration-by-parts identities to express the scalar integral in terms of two master-topology integrals and present an explicit analytic expression for the pentabox scalar integral as a series expansion in ep = (4-D)/2. We also give an algorithm based on integration by parts for relating the generic tensor integrals to the same two master integrals and provide general formulae describing the master integrals in arbitrary dimension and with general powers of propagators.
0904.4561
Vikram Rentala
Hitoshi Murayama and Vikram Rentala
Randall-Sundrum graviton spin determination using azimuthal angular dependence
7 pages, 6 figures
null
10.1103/PhysRevD.85.095005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum interference of helicity amplitudes provides a powerful tool for measuring the spins of new particles. By looking at the azimuthal angular dependence of the differential cross-section in the production followed by decay of a new particle species one can determine its spin by looking at the various cosine modes. The heavy spin-2 Kaluza-Klein (KK) graviton provides a unique signature with a $\cos{(4 \phi)}$ mode. We study the feasibility of this approach to measuring the spin of the KK graviton in the Randall-Sundrum Model at the LHC.
[ { "created": "Wed, 29 Apr 2009 09:20:40 GMT", "version": "v1" } ]
2013-05-30
[ [ "Murayama", "Hitoshi", "" ], [ "Rentala", "Vikram", "" ] ]
Quantum interference of helicity amplitudes provides a powerful tool for measuring the spins of new particles. By looking at the azimuthal angular dependence of the differential cross-section in the production followed by decay of a new particle species one can determine its spin by looking at the various cosine modes. The heavy spin-2 Kaluza-Klein (KK) graviton provides a unique signature with a $\cos{(4 \phi)}$ mode. We study the feasibility of this approach to measuring the spin of the KK graviton in the Randall-Sundrum Model at the LHC.
hep-ph/0412407
Ladrem Madjid
M. Ladrem and A. Ait-El-Djoudi
Finite-Size Effects and Scaling for the Thermal QCD Deconfinement Phase Transition within the Exact Color-Singlet Partition Function
09 pages, 11 Postscript figures
Eur.Phys.J.C44:257-265,2005
10.1140/epjc/s2005-02357-y
null
hep-ph
null
We study the finite-size effects for the thermal QCD Deconfinement Phase Transition (DPT), and use a numerical finite size scaling analysis to extract the scaling exponents characterizing its scaling behavior when approaching the thermodynamic limit. For this, we use a simple model of coexistence of hadronic gas and color-singlet Quark Gluon Plasma (QGP) phases in a finite volume. The Color-Singlet Partition Function (CSPF) of the QGP cannot be exactly calculated and is usually derived within the saddle point approximation. When we try to do calculations with such an approximate CSPF, a problem arises in the limit of small temperatures and/or volumes (VT3<<1), requiring then additional approximations if we want to carry out calculations. We propose in this work a new method for an accurate calculation of any quantity of the finite system, without explicitly calculating the CSPF itself and without any approximation. By probing the behavior of some useful thermodynamic response functions on the hole range of temperature, it turns out that in a finite size system, all singularities in the thermodynamic limit are smeared out and the transition point is shifted away. A numerical finite size scaling analysis of the obtained data allows us to determine the scaling exponents of the QCD DPT. Our results expressing the equality between their values and the space dimensionality is a consequence of the singularity characterizing a first order phase transition and agree very well with the predictions of other FSS theoretical approaches and with the results of both lattice QCD and Monte Carlo models calculations.
[ { "created": "Wed, 29 Dec 2004 12:23:57 GMT", "version": "v1" } ]
2009-01-07
[ [ "Ladrem", "M.", "" ], [ "Ait-El-Djoudi", "A.", "" ] ]
We study the finite-size effects for the thermal QCD Deconfinement Phase Transition (DPT), and use a numerical finite size scaling analysis to extract the scaling exponents characterizing its scaling behavior when approaching the thermodynamic limit. For this, we use a simple model of coexistence of hadronic gas and color-singlet Quark Gluon Plasma (QGP) phases in a finite volume. The Color-Singlet Partition Function (CSPF) of the QGP cannot be exactly calculated and is usually derived within the saddle point approximation. When we try to do calculations with such an approximate CSPF, a problem arises in the limit of small temperatures and/or volumes (VT3<<1), requiring then additional approximations if we want to carry out calculations. We propose in this work a new method for an accurate calculation of any quantity of the finite system, without explicitly calculating the CSPF itself and without any approximation. By probing the behavior of some useful thermodynamic response functions on the hole range of temperature, it turns out that in a finite size system, all singularities in the thermodynamic limit are smeared out and the transition point is shifted away. A numerical finite size scaling analysis of the obtained data allows us to determine the scaling exponents of the QCD DPT. Our results expressing the equality between their values and the space dimensionality is a consequence of the singularity characterizing a first order phase transition and agree very well with the predictions of other FSS theoretical approaches and with the results of both lattice QCD and Monte Carlo models calculations.
1812.06452
Henning Bahl
Henning Bahl
Pole mass determination in presence of heavy particles
37 pages,3 figures; small corrections; matches version to be published in JHEP;
null
10.1007/JHEP02(2019)121
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the determination of the Higgs-boson propagator poles in the MSSM. Based upon earlier works, we point out that in case of a large hierarchy between the electroweak scale and one or more SUSY masses a numerical determination with $\overline{\text{DR}}$ Higgs field renormalization induces higher order terms which would cancel in a more complete calculation. The origin of these terms is the momentum dependence of contributions involving at least one of the heavy particles. We present two different methods to avoid their appearance. In the first approach, the poles are determined by expanding around the one-loop solutions. In the second approach, a "heavy-OS" Higgs field renormalization is employed in order to absorb the momentum dependence of heavy contributions. We will find that the first approach leads to an unwanted behaviour of the Higgs boson mass predictions close to crossing points where two Higgs bosons that mix with each other are almost mass degenerate. These problems are avoided in the second approach, which became the default approach used in the public code FeynHiggs. Despite the discussion being very specific to the MSSM, the argumentation and the methods presented in this work are straightforwardly applicable to the determination of propagator poles in other models involving a large mass hierarchy.
[ { "created": "Sun, 16 Dec 2018 12:11:30 GMT", "version": "v1" }, { "created": "Thu, 28 Feb 2019 11:09:41 GMT", "version": "v2" } ]
2019-03-27
[ [ "Bahl", "Henning", "" ] ]
We investigate the determination of the Higgs-boson propagator poles in the MSSM. Based upon earlier works, we point out that in case of a large hierarchy between the electroweak scale and one or more SUSY masses a numerical determination with $\overline{\text{DR}}$ Higgs field renormalization induces higher order terms which would cancel in a more complete calculation. The origin of these terms is the momentum dependence of contributions involving at least one of the heavy particles. We present two different methods to avoid their appearance. In the first approach, the poles are determined by expanding around the one-loop solutions. In the second approach, a "heavy-OS" Higgs field renormalization is employed in order to absorb the momentum dependence of heavy contributions. We will find that the first approach leads to an unwanted behaviour of the Higgs boson mass predictions close to crossing points where two Higgs bosons that mix with each other are almost mass degenerate. These problems are avoided in the second approach, which became the default approach used in the public code FeynHiggs. Despite the discussion being very specific to the MSSM, the argumentation and the methods presented in this work are straightforwardly applicable to the determination of propagator poles in other models involving a large mass hierarchy.
1404.6599
Patrick Stengel
Nicolas Fernandez, Jason Kumar, Ilsoo Seong and Patrick Stengel
Complementary Constraints on Light Dark Matter from Heavy Quarkonium Decays
19 pages, 5 figures, Errors corrected
Phys. Rev. D 90, 015029 (2014)
10.1103/PhysRevD.90.015029
UH-511-1233-2014
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate constraints on the properties of light dark matter which can be obtained from analysis of invisible quarkonium decays at high intensity electron-positron colliders in the framework of a low energy effective field theory. A matrix element analysis of all contact operators pertinent for these meson decays allows for a model-independent calculation of associated dark matter-nucleon scattering and dark matter annihilation cross sections. Assuming dark matter couples universally to all quark flavors, we then obtain bounds on nucleon scattering which complement direct dark matter detection searches. In contrast to similar analyses of monojet searches at high energy colliders, B and charm factories are more suitable probes of light dark matter interactions with less massive mediators. Relevant bounds on dark matter annihilation arising from gamma ray searches of dwarf spheroidal galaxies are also presented.
[ { "created": "Sat, 26 Apr 2014 04:02:44 GMT", "version": "v1" }, { "created": "Thu, 24 Jul 2014 22:31:49 GMT", "version": "v2" }, { "created": "Thu, 19 Mar 2015 23:12:16 GMT", "version": "v3" } ]
2015-03-23
[ [ "Fernandez", "Nicolas", "" ], [ "Kumar", "Jason", "" ], [ "Seong", "Ilsoo", "" ], [ "Stengel", "Patrick", "" ] ]
We investigate constraints on the properties of light dark matter which can be obtained from analysis of invisible quarkonium decays at high intensity electron-positron colliders in the framework of a low energy effective field theory. A matrix element analysis of all contact operators pertinent for these meson decays allows for a model-independent calculation of associated dark matter-nucleon scattering and dark matter annihilation cross sections. Assuming dark matter couples universally to all quark flavors, we then obtain bounds on nucleon scattering which complement direct dark matter detection searches. In contrast to similar analyses of monojet searches at high energy colliders, B and charm factories are more suitable probes of light dark matter interactions with less massive mediators. Relevant bounds on dark matter annihilation arising from gamma ray searches of dwarf spheroidal galaxies are also presented.
hep-ph/0506286
Stefan Groote
S. Groote, J.G. K\"orner and A.A. Pivovarov
On the evaluation of a certain class of Feynman diagrams in x-space: Sunrise-type topologies at any loop order
100 pages, 16 eps-figures included
AnnalsPhys.322:2374-2445,2007
10.1016/j.aop.2006.11.001
MZ-TH/05-08
hep-ph
null
We review recently developed new powerful techniques to compute a class of Feynman diagrams at any loop order, known as sunrise-type diagrams. These sunrise-type topologies have many important applications in many different fields of physics and we believe it to be timely to discuss their evaluation from a unified point of view. The method is based on the analysis of the diagrams directly in configuration space which, in the case of the sunrise-type diagrams and diagrams related to them, leads to enormous simplifications as compared to the traditional evaluation of loops in momentum space. We present explicit formulae for their analytical evaluation for arbitrary mass configurations and arbitrary dimensions at any loop order. We discuss several limiting cases of their kinematical regimes which are e.g. relevant for applications in HQET and NRQCD.
[ { "created": "Tue, 28 Jun 2005 09:18:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Pivovarov", "A. A.", "" ] ]
We review recently developed new powerful techniques to compute a class of Feynman diagrams at any loop order, known as sunrise-type diagrams. These sunrise-type topologies have many important applications in many different fields of physics and we believe it to be timely to discuss their evaluation from a unified point of view. The method is based on the analysis of the diagrams directly in configuration space which, in the case of the sunrise-type diagrams and diagrams related to them, leads to enormous simplifications as compared to the traditional evaluation of loops in momentum space. We present explicit formulae for their analytical evaluation for arbitrary mass configurations and arbitrary dimensions at any loop order. We discuss several limiting cases of their kinematical regimes which are e.g. relevant for applications in HQET and NRQCD.
hep-ph/0209125
Zhang Zhao-xi
Xing-Gang Wu, Chao-Hsi Chang (Zhao-Xi Zhang), Yu-Qi Chen and Zheng-Yun Fang
The meson $B_c$ annihilation to leptons and inclusive light hadrons
26 pages, 5 figures (6 eps-files), submitted to Phys. Rev. D
Phys.Rev.D67:094001,2003
10.1103/PhysRevD.67.094001
null
hep-ph
null
The annihilation of the $B_c$ meson to leptons and inclusive light hadrons is analyzed in the framework of nonrelativistic QCD (NRQCD) factorization. We find that the decay mode, which escapes from the helicity suppression, contributes a sizable fraction width. According to the analysis, the branching ratio due to the contribution from the color-singlet component of the meson $B_c$ can be of order (10^{-2}). We also estimate the contributions from the color-octet components. With the velocity scaling rule of NRQCD, we find that the color-octet contributions are sizable too, especially, in certain phase space of the annihilation they are greater than (or comparative to) the color-singlet component. A few observables relevant to the spectrum of charged lepton are suggested, that may be used as measurements on the color-octet and color-singlet components in the future $B_c$ experiments. A typical long distance contribution in the annihilation is estimated too.
[ { "created": "Thu, 12 Sep 2002 12:29:08 GMT", "version": "v1" } ]
2011-03-23
[ [ "Wu", "Xing-Gang", "", "Zhao-Xi Zhang" ], [ "Chang", "Chao-Hsi", "", "Zhao-Xi Zhang" ], [ "Chen", "Yu-Qi", "" ], [ "Fang", "Zheng-Yun", "" ] ]
The annihilation of the $B_c$ meson to leptons and inclusive light hadrons is analyzed in the framework of nonrelativistic QCD (NRQCD) factorization. We find that the decay mode, which escapes from the helicity suppression, contributes a sizable fraction width. According to the analysis, the branching ratio due to the contribution from the color-singlet component of the meson $B_c$ can be of order (10^{-2}). We also estimate the contributions from the color-octet components. With the velocity scaling rule of NRQCD, we find that the color-octet contributions are sizable too, especially, in certain phase space of the annihilation they are greater than (or comparative to) the color-singlet component. A few observables relevant to the spectrum of charged lepton are suggested, that may be used as measurements on the color-octet and color-singlet components in the future $B_c$ experiments. A typical long distance contribution in the annihilation is estimated too.
2208.05431
Vincenzo Branchina
C. Branchina, V. Branchina, F. Contino
Physical Tuning and Naturalness
7 pages, 4 figures
null
10.1103/PhysRevD.107.096012
null
hep-ph cond-mat.stat-mech hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
We present a radically new proposal for the solution of the naturalness/hierarchy problem, where the fine-tuning of the Higgs mass finds its physical explanation and the well-known multiplicative renormalization of the usual perturbative approach emerges as an IR property of the non-perturbative running of the mass.
[ { "created": "Wed, 10 Aug 2022 16:35:11 GMT", "version": "v1" } ]
2023-05-24
[ [ "Branchina", "C.", "" ], [ "Branchina", "V.", "" ], [ "Contino", "F.", "" ] ]
We present a radically new proposal for the solution of the naturalness/hierarchy problem, where the fine-tuning of the Higgs mass finds its physical explanation and the well-known multiplicative renormalization of the usual perturbative approach emerges as an IR property of the non-perturbative running of the mass.
1108.4337
Mirco Cannoni
M. Cannoni
On the formalism and upper limits for spin-dependent cross sections in dark matter elastic scattering with nuclei
12 pages, two column, 5 figures. Minor corrections and typos removed. Accepted in PRD
Phys. Rev. D 84, 095017 (2011)
10.1103/PhysRevD.84.095017
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revise the spin-dependent neutralino-nucleus elastic scattering comparing the formalisms and approximations found in literature for the momentum transfer dependent structure functions. We argue that one of the normalized structure functions of Divari, Kosmas, Vergados and Skouras is all that one needs to correctly take into account the detailed nuclear physics information provided by shell-model calculations. The factorization of the particle physics degrees of freedom from the nuclear physics momentum dependent structure functions implied by this formalism allows for a better understanding of the so-called model independent method for setting upper limits. We further discuss the possibility of experiments with spin-dependent sensitivity like COUPP to test or set limits on the proton spin-dependent cross section in the framework of the stau co-annihilation region of the constrained minimal supersymmetric standard model. For this model with $A_0 =0$, we provide a fitting formula by which it is possible to convert an upper limit on the spin-independent cross section as a function of the neutralino mass directly into an exclusion plot in the ($m_{1/2}$, $\tan\beta$) plane.
[ { "created": "Mon, 22 Aug 2011 15:01:25 GMT", "version": "v1" }, { "created": "Tue, 25 Oct 2011 14:40:38 GMT", "version": "v2" } ]
2011-11-22
[ [ "Cannoni", "M.", "" ] ]
We revise the spin-dependent neutralino-nucleus elastic scattering comparing the formalisms and approximations found in literature for the momentum transfer dependent structure functions. We argue that one of the normalized structure functions of Divari, Kosmas, Vergados and Skouras is all that one needs to correctly take into account the detailed nuclear physics information provided by shell-model calculations. The factorization of the particle physics degrees of freedom from the nuclear physics momentum dependent structure functions implied by this formalism allows for a better understanding of the so-called model independent method for setting upper limits. We further discuss the possibility of experiments with spin-dependent sensitivity like COUPP to test or set limits on the proton spin-dependent cross section in the framework of the stau co-annihilation region of the constrained minimal supersymmetric standard model. For this model with $A_0 =0$, we provide a fitting formula by which it is possible to convert an upper limit on the spin-independent cross section as a function of the neutralino mass directly into an exclusion plot in the ($m_{1/2}$, $\tan\beta$) plane.
1707.00028
Joshua Bendavid
Joshua Bendavid
Efficient Monte Carlo Integration Using Boosted Decision Trees and Generative Deep Neural Networks
null
null
null
null
hep-ph physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New machine learning based algorithms have been developed and tested for Monte Carlo integration based on generative Boosted Decision Trees and Deep Neural Networks. Both of these algorithms exhibit substantial improvements compared to existing algorithms for non-factorizable integrands in terms of the achievable integration precision for a given number of target function evaluations. Large scale Monte Carlo generation of complex collider physics processes with improved efficiency can be achieved by implementing these algorithms into commonly used matrix element Monte Carlo generators once their robustness is demonstrated and performance validated for the relevant classes of matrix elements.
[ { "created": "Fri, 30 Jun 2017 19:18:43 GMT", "version": "v1" } ]
2017-07-04
[ [ "Bendavid", "Joshua", "" ] ]
New machine learning based algorithms have been developed and tested for Monte Carlo integration based on generative Boosted Decision Trees and Deep Neural Networks. Both of these algorithms exhibit substantial improvements compared to existing algorithms for non-factorizable integrands in terms of the achievable integration precision for a given number of target function evaluations. Large scale Monte Carlo generation of complex collider physics processes with improved efficiency can be achieved by implementing these algorithms into commonly used matrix element Monte Carlo generators once their robustness is demonstrated and performance validated for the relevant classes of matrix elements.
hep-ph/9911436
Jungil Lee
Eric Braaten (Ohio State), Bernd A. Kniehl and Jungil Lee (Hamburg)
Polarization of Prompt J/psi at the Tevatron
4 pages, 2 figures, one reference added, accepted for publication in Phys. Rev. D
Phys.Rev.D62:094005,2000
10.1103/PhysRevD.62.094005
DESY 99-175
hep-ph
null
The polarization of prompt J/psi at the Fermilab Tevatron is calculated within the nonrelativistic QCD factorization framework. The contribution from radiative decays of P-wave charmonium states decreases, but does not eliminate, the transverse polarization at large transverse momentum. The angular distribution parameter alpha for leptonic decays of the J/\psi is predicted to increase from near 0 at p_T = 5 GeV to about 0.5 at p_T = 20 GeV. The prediction is consistent with measurements by the CDF Collaboration at intermediate values of p_T, but disagrees by about 3 standard deviations at the largest values of p_T measured.
[ { "created": "Mon, 22 Nov 1999 16:19:46 GMT", "version": "v1" }, { "created": "Wed, 17 May 2000 23:45:15 GMT", "version": "v2" }, { "created": "Wed, 26 Jul 2000 17:24:36 GMT", "version": "v3" } ]
2011-03-23
[ [ "Braaten", "Eric", "", "Ohio State" ], [ "Kniehl", "Bernd A.", "", "Hamburg" ], [ "Lee", "Jungil", "", "Hamburg" ] ]
The polarization of prompt J/psi at the Fermilab Tevatron is calculated within the nonrelativistic QCD factorization framework. The contribution from radiative decays of P-wave charmonium states decreases, but does not eliminate, the transverse polarization at large transverse momentum. The angular distribution parameter alpha for leptonic decays of the J/\psi is predicted to increase from near 0 at p_T = 5 GeV to about 0.5 at p_T = 20 GeV. The prediction is consistent with measurements by the CDF Collaboration at intermediate values of p_T, but disagrees by about 3 standard deviations at the largest values of p_T measured.
1708.03660
Jorge Gamboa
Ariel Arza and Jorge Gamboa
Birefringence and hidden photons
title changed and a plot added
Mod. Phys. Lett. A33, 1850082 (2018)
10.1142/S0217732318500827
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a model where photons interact with hidden photons and millicharged particles through a kinetic mixing term. Particularly, we focus in vacuum birefringence effects and we find a bound for the millicharged parameter assuming that hidden photons are a piece of the local dark matter density
[ { "created": "Fri, 11 Aug 2017 18:44:13 GMT", "version": "v1" }, { "created": "Wed, 23 May 2018 19:10:00 GMT", "version": "v2" } ]
2018-06-13
[ [ "Arza", "Ariel", "" ], [ "Gamboa", "Jorge", "" ] ]
We study a model where photons interact with hidden photons and millicharged particles through a kinetic mixing term. Particularly, we focus in vacuum birefringence effects and we find a bound for the millicharged parameter assuming that hidden photons are a piece of the local dark matter density
hep-ph/0406238
Marina Markina
M.N.Chernodub and B.L.Ioffe
The influence of baryons on the chiral phase transition in QCD
5 pages, 4 figures, presented to Ian Kogan Memorial Volume
null
10.1142/9789812775344_0008
null
hep-ph
null
A qualitative analysis of the chiral phase transition in QCD with two massless quarks and non--zero baryon density is performed. It is assumed that at zero baryonic density, $\rho=0$, the temperature phase transition is of the second order. Due to a specific power dependence of baryon masses on the chiral condensate the phase transition becomes of the first order at the temperature $T=T_{\mathrm{ph}}(\rho)$ for $\rho>0$. At temperatures $T_{\mathrm{cont}}(\rho) > T > T_{\mathrm{ph}}(\rho)$ there is a mixed phase consisting of the quark phase (stable) and the hadron phase (unstable). At the temperature $T = T_{\mathrm{cont}}(\rho)$ the system experiences a continuous transition to the pure chirally symmetric phase.
[ { "created": "Tue, 22 Jun 2004 09:59:20 GMT", "version": "v1" } ]
2016-11-23
[ [ "Chernodub", "M. N.", "" ], [ "Ioffe", "B. L.", "" ] ]
A qualitative analysis of the chiral phase transition in QCD with two massless quarks and non--zero baryon density is performed. It is assumed that at zero baryonic density, $\rho=0$, the temperature phase transition is of the second order. Due to a specific power dependence of baryon masses on the chiral condensate the phase transition becomes of the first order at the temperature $T=T_{\mathrm{ph}}(\rho)$ for $\rho>0$. At temperatures $T_{\mathrm{cont}}(\rho) > T > T_{\mathrm{ph}}(\rho)$ there is a mixed phase consisting of the quark phase (stable) and the hadron phase (unstable). At the temperature $T = T_{\mathrm{cont}}(\rho)$ the system experiences a continuous transition to the pure chirally symmetric phase.
2307.14922
N\'estor Armesto
Tolga Altinoluk, N\'estor Armesto, Alexander Kovner, Michael Lublinsky
Single inclusive particle production at next-to-leading order in proton-nucleus collisions at forward rapidities: hybrid approach meets TMD factorization
LaTeX, 39 pages, 4 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We revisit the calculation of the cross section for forward inclusive single hadron production in $pA$ collisions within the hybrid approach. We show that the proper framework to perform this calculation beyond leading order is not the collinear factorization, as has been assumed so far, but the TMD factorized framework. Within the TMD factorized approach we show that all the large transverse logarithms appearing in the fixed order calculation, are resummed into the evolution of the TMD PDFs and TMD FFs with factorization scale. The resulting expressions, when written in terms of TMDs evolved to the appropriate, physically well understood factorization scale, contain no additional large logarithms. The absence of any large logarithms in the resummed result should ensure positivity of the cross section and eradicate the persistent problem that have plagued the previous attempts at calculating this observable in the hybrid approach.
[ { "created": "Thu, 27 Jul 2023 15:03:31 GMT", "version": "v1" } ]
2023-07-28
[ [ "Altinoluk", "Tolga", "" ], [ "Armesto", "Néstor", "" ], [ "Kovner", "Alexander", "" ], [ "Lublinsky", "Michael", "" ] ]
We revisit the calculation of the cross section for forward inclusive single hadron production in $pA$ collisions within the hybrid approach. We show that the proper framework to perform this calculation beyond leading order is not the collinear factorization, as has been assumed so far, but the TMD factorized framework. Within the TMD factorized approach we show that all the large transverse logarithms appearing in the fixed order calculation, are resummed into the evolution of the TMD PDFs and TMD FFs with factorization scale. The resulting expressions, when written in terms of TMDs evolved to the appropriate, physically well understood factorization scale, contain no additional large logarithms. The absence of any large logarithms in the resummed result should ensure positivity of the cross section and eradicate the persistent problem that have plagued the previous attempts at calculating this observable in the hybrid approach.
1910.03221
Masatoshi Morimoto
M. Morimoto (Kochi Univ., Japan), Y. Tsue (Kochi Univ., Japan), J. da Providencia (Univ. de Coimbra, Portugal), C. Providencia (Univ. de Coimbra, Portugal), M. Yamamura (Kansai Univ., Japan)
Spin polarizations under a pseudovector interaction between quarks with the Kobayashi-Maskawa-'t Hooft term in high density quark matter
14 pages, 14 figures
null
10.1142/S0218301320500032
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A possibility of a quark spin polarization originated from a pseudovector condensate is investigated in the three-flavor Nambu-Jona-Lasinio model with the Kobayashi-Maskawa-'t Hooft interaction which leads to flavor mixing. It is shown that a pseudovector condensate related to the strange quark easily occurs compared with pseudovector condensate related to light quarks. Further, it is shown that the pseudovector condensate related to the strange quark appears at a slightly small chemical potential by the effect of the flavor mixing due to the Kobayashi-Maskawa-'t Hooft interaction.
[ { "created": "Tue, 8 Oct 2019 05:37:08 GMT", "version": "v1" }, { "created": "Sat, 12 Oct 2019 02:08:00 GMT", "version": "v2" }, { "created": "Fri, 13 Mar 2020 08:33:23 GMT", "version": "v3" } ]
2020-03-16
[ [ "Morimoto", "M.", "", "Kochi Univ., Japan" ], [ "Tsue", "Y.", "", "Kochi Univ., Japan" ], [ "da Providencia", "J.", "", "Univ. de Coimbra, Portugal" ], [ "Providencia", "C.", "", "Univ. de Coimbra,\n Portugal" ], [ "Yamamura", "M.", "", "Kansai Univ., Japan" ] ]
A possibility of a quark spin polarization originated from a pseudovector condensate is investigated in the three-flavor Nambu-Jona-Lasinio model with the Kobayashi-Maskawa-'t Hooft interaction which leads to flavor mixing. It is shown that a pseudovector condensate related to the strange quark easily occurs compared with pseudovector condensate related to light quarks. Further, it is shown that the pseudovector condensate related to the strange quark appears at a slightly small chemical potential by the effect of the flavor mixing due to the Kobayashi-Maskawa-'t Hooft interaction.
hep-ph/0703017
Nobuhito Maru
C.S. Lim and Nobuhito Maru
Calculable One-Loop Contributions to S and T Parameters in the Gauge-Higgs Unification
25 pages, 1 eps file, minor corrections, version to appear in PRD
Phys.Rev.D75:115011,2007
10.1103/PhysRevD.75.115011
KOBE-TH-07-01
hep-ph
null
We investigate the one-loop contributions to S and T oblique parameteres in gauge-Higgs unification. We show that these parameters are finite in five dimensional space-time, but are divergent in more than five dimensions. Remarkably, however, we find that a particular linear combination of S and T parameters, S - 4 \cos \theta_{W} T, becomes finite for six dimensional space-time, though each of these parameters is divergent. This is because, in the Gauge-Higgs unification scenario, the operators relevant for S and T parameters are not independent, but are included in a unique higher dimensional gauge invariant operator. Thus the predictable linear combination is model independent, irrespectibly of the detail of the matter content.
[ { "created": "Fri, 2 Mar 2007 00:22:48 GMT", "version": "v1" }, { "created": "Wed, 7 Mar 2007 05:04:49 GMT", "version": "v2" }, { "created": "Fri, 13 Apr 2007 05:04:21 GMT", "version": "v3" } ]
2008-11-26
[ [ "Lim", "C. S.", "" ], [ "Maru", "Nobuhito", "" ] ]
We investigate the one-loop contributions to S and T oblique parameteres in gauge-Higgs unification. We show that these parameters are finite in five dimensional space-time, but are divergent in more than five dimensions. Remarkably, however, we find that a particular linear combination of S and T parameters, S - 4 \cos \theta_{W} T, becomes finite for six dimensional space-time, though each of these parameters is divergent. This is because, in the Gauge-Higgs unification scenario, the operators relevant for S and T parameters are not independent, but are included in a unique higher dimensional gauge invariant operator. Thus the predictable linear combination is model independent, irrespectibly of the detail of the matter content.
0901.4332
Mario E. Gomez
M.E. Gomez, S. Lola, P. Naranjo and J. Rodriguez-Quintero
Dark Matter and Yukawa Unification with Massive Neutrinos
Proceedings of 4th International Workshop on the Dark Side of the Universe (DSU 2008), Cairo, June 2008. 7 pages, 4 figures
AIP Conf.Proc.1115:273-278,2009
10.1063/1.3131510
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the WMAP dark matter constraints on Yukawa Unification in the presence of massive neutrinos. The large neutrino mixing indicated by the data modifies the predictions for the bottom quark mass, and enables Yukawa also for large $\tan\beta$, and for positive $\mu$ that were previously disfavoured. As a result, the allowed parameter space for neutralino dark matter also increases, particularly for areas with resonant enhancement of the neutralino relic density.
[ { "created": "Tue, 27 Jan 2009 20:54:59 GMT", "version": "v1" }, { "created": "Tue, 27 Jan 2009 21:02:16 GMT", "version": "v2" } ]
2009-05-01
[ [ "Gomez", "M. E.", "" ], [ "Lola", "S.", "" ], [ "Naranjo", "P.", "" ], [ "Rodriguez-Quintero", "J.", "" ] ]
We revisit the WMAP dark matter constraints on Yukawa Unification in the presence of massive neutrinos. The large neutrino mixing indicated by the data modifies the predictions for the bottom quark mass, and enables Yukawa also for large $\tan\beta$, and for positive $\mu$ that were previously disfavoured. As a result, the allowed parameter space for neutralino dark matter also increases, particularly for areas with resonant enhancement of the neutralino relic density.
2303.05990
Fernando Navarra
L. M. Abreu, F. S. Navarra, M. Nielsen, H. P. L. Vieira
Multiplicity of $Z_{cs}(3985)$ in heavy ion collisions
9 pages, 8 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Using the coalescence model we compute the multiplicity of $Z_{cs} (3985)^-$ (treated as a compact tetraquark) at the end of the quark gluon plasma phase in heavy ion collisions. Then we study the time evolution of this state in the hot hadron gas phase. We calculate the thermal cross sections for the collisions of the $Z_{cs} (3985)^-$ with light mesons using effective Lagrangians and form factors derived from QCD sum rules for the vertices $Z_{cs}\bar{D}_{s }^* D $ and $Z_{cs} \bar{D}_{s} D^{*}$. We solve the kinetic equation and find how the $Z_{cs} (3985)^-$ multiplicity is affected by the considered reactions during the expansion of the hadronic matter. A comparison with the statistical hadronization model predictions is presented. Our results show that the tetraquark yield increases by a factor of about $2-3$ from the hadronization to the kinetic freeze-out. We also make predictions for the dependence of the $Z_{cs} (3985)^-$ yield on the centrality, the center-of-mass energy and the charged hadron multiplicity measured at midrapidity $ \left[ d N_{ch} / d \eta (\eta < 0.5)\right]$.
[ { "created": "Fri, 10 Mar 2023 15:45:26 GMT", "version": "v1" } ]
2023-03-13
[ [ "Abreu", "L. M.", "" ], [ "Navarra", "F. S.", "" ], [ "Nielsen", "M.", "" ], [ "Vieira", "H. P. L.", "" ] ]
Using the coalescence model we compute the multiplicity of $Z_{cs} (3985)^-$ (treated as a compact tetraquark) at the end of the quark gluon plasma phase in heavy ion collisions. Then we study the time evolution of this state in the hot hadron gas phase. We calculate the thermal cross sections for the collisions of the $Z_{cs} (3985)^-$ with light mesons using effective Lagrangians and form factors derived from QCD sum rules for the vertices $Z_{cs}\bar{D}_{s }^* D $ and $Z_{cs} \bar{D}_{s} D^{*}$. We solve the kinetic equation and find how the $Z_{cs} (3985)^-$ multiplicity is affected by the considered reactions during the expansion of the hadronic matter. A comparison with the statistical hadronization model predictions is presented. Our results show that the tetraquark yield increases by a factor of about $2-3$ from the hadronization to the kinetic freeze-out. We also make predictions for the dependence of the $Z_{cs} (3985)^-$ yield on the centrality, the center-of-mass energy and the charged hadron multiplicity measured at midrapidity $ \left[ d N_{ch} / d \eta (\eta < 0.5)\right]$.
1308.1501
David M. Straub
Wolfgang Altmannshofer and David M. Straub
New physics in $B \to K^*\mu\mu$?
31 pages, 10 figures. v3: Minor clarifications; table with SM predictions and experimental averages added; matches journal version
Eur.Phys.J. C73 (2013) 2646
10.1140/epjc/s10052-013-2646-9
FERMILAB-PUB-13-310-T, MITP/13-047
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent experimental results on angular observables in the rare decay $B\to K^*\mu^+\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining all relevant data on $b \to s$ rare decays, we show that a consistent explanation of most anomalies can be obtained by new physics contributing simultaneously to the semi-leptonic vector operator $O_9$ and its chirality-flipped counterpart $O_9'$. A partial explanation is possible with new physics in $O_9$ or in dipole operators only. We study in detail the implications for models of new physics, in particular the minimal supersymmetric standard model, models with partial compositeness and generic models with flavour-changing $Z^\prime$ bosons. In all considered models, contributions to $B\to K^*\mu^+\mu^-$ of the preferred size imply a spectrum close to the TeV scale. We stress that measurements of CP asymmetries in $B\to K^*\mu^+\mu^-$ could provide valuable information to narrow down possible new physics explanations.
[ { "created": "Wed, 7 Aug 2013 08:29:25 GMT", "version": "v1" }, { "created": "Tue, 13 Aug 2013 18:11:06 GMT", "version": "v2" }, { "created": "Wed, 20 Nov 2013 10:19:35 GMT", "version": "v3" } ]
2014-09-05
[ [ "Altmannshofer", "Wolfgang", "" ], [ "Straub", "David M.", "" ] ]
Recent experimental results on angular observables in the rare decay $B\to K^*\mu^+\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining all relevant data on $b \to s$ rare decays, we show that a consistent explanation of most anomalies can be obtained by new physics contributing simultaneously to the semi-leptonic vector operator $O_9$ and its chirality-flipped counterpart $O_9'$. A partial explanation is possible with new physics in $O_9$ or in dipole operators only. We study in detail the implications for models of new physics, in particular the minimal supersymmetric standard model, models with partial compositeness and generic models with flavour-changing $Z^\prime$ bosons. In all considered models, contributions to $B\to K^*\mu^+\mu^-$ of the preferred size imply a spectrum close to the TeV scale. We stress that measurements of CP asymmetries in $B\to K^*\mu^+\mu^-$ could provide valuable information to narrow down possible new physics explanations.
1203.5640
Jean Cleymans
J. Cleymans
The Thermal Model at the Large Hadron Collider
8 pages, 3 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A discussion is presented of results with identified particles at the Large Hadron Collider. Possible deviations from the standard statistical distributions are investigated by considering in detail results obtained using the Tsallis distribution. Matter-antimatter production is discussed within the framework of chemical equilibrium in \pp and heavy ion collisions.
[ { "created": "Mon, 26 Mar 2012 11:52:45 GMT", "version": "v1" } ]
2012-03-27
[ [ "Cleymans", "J.", "" ] ]
A discussion is presented of results with identified particles at the Large Hadron Collider. Possible deviations from the standard statistical distributions are investigated by considering in detail results obtained using the Tsallis distribution. Matter-antimatter production is discussed within the framework of chemical equilibrium in \pp and heavy ion collisions.
2011.11655
Matthias Steinhauser
Matteo Fael, Kay Sch\"onwald and Matthias Steinhauser
On the relation between the $\overline{\mathrm{MS}}$ and the kinetic mass of heavy quarks
53 pages, v2: Two typos in eq.(88) fixed
Phys. Rev. D 103, 014005 (2021)
10.1103/PhysRevD.103.014005
P3H-20-73, TTP20-040
hep-ph
http://creativecommons.org/licenses/by/4.0/
We compute the relation between the pole mass and the kinetic mass of a heavy quark to three loops. Using the known relation between the pole and the $\overline{\rm MS}$ mass we obtain precise conversion relations between the $\overline{\rm MS}$ and kinetic masses. The kinetic mass is defined via the moments of the spectral function for the scattering involving a heavy quark close to threshold. This requires the computation of the imaginary part of a forward scattering amplitude up to three-loop order. We discuss in detail the expansion procedure and the reduction to master integrals. For the latter analytic results are provided. We apply our result both to charm and bottom quark masses. In the latter case we compute and include finite charm quark mass effects. Furthermore, we determine the large-$\beta_0$ result for the conversion formula at four-loop order. For the bottom quark we estimate the uncertainty in the conversion between the $\overline{\rm MS}$ and kinetic masses to about 15 MeV which is an improvement by a factor two to three as compared to the two-loop formula. The improved precision is crucial for the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ at Belle II.
[ { "created": "Mon, 23 Nov 2020 19:00:14 GMT", "version": "v1" }, { "created": "Sun, 6 Feb 2022 05:54:53 GMT", "version": "v2" } ]
2022-02-08
[ [ "Fael", "Matteo", "" ], [ "Schönwald", "Kay", "" ], [ "Steinhauser", "Matthias", "" ] ]
We compute the relation between the pole mass and the kinetic mass of a heavy quark to three loops. Using the known relation between the pole and the $\overline{\rm MS}$ mass we obtain precise conversion relations between the $\overline{\rm MS}$ and kinetic masses. The kinetic mass is defined via the moments of the spectral function for the scattering involving a heavy quark close to threshold. This requires the computation of the imaginary part of a forward scattering amplitude up to three-loop order. We discuss in detail the expansion procedure and the reduction to master integrals. For the latter analytic results are provided. We apply our result both to charm and bottom quark masses. In the latter case we compute and include finite charm quark mass effects. Furthermore, we determine the large-$\beta_0$ result for the conversion formula at four-loop order. For the bottom quark we estimate the uncertainty in the conversion between the $\overline{\rm MS}$ and kinetic masses to about 15 MeV which is an improvement by a factor two to three as compared to the two-loop formula. The improved precision is crucial for the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ at Belle II.
2307.05967
Tanjona Radonirina Rabemananjara
Tanjona Rabemananjara
Towards an integrated determination of proton, deuteron and nuclear PDFs
Presented at conference DIS2023: XXX International Workshop on Deep-Inelastic Scattering and Related Subjects, Michigan State University, USA, 27-31 March 2023
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present progress towards a unified framework enabling the simultaneous determination of the parton distribution functions (PDFs) of the proton, deuteron, and nuclei up to lead $(^{208}\rm{Pb})$. Our approach is based on the integration of the fitting framework underlying the nNNPDF3.0 determination of nuclear PDFs into that adopted for the NNPDF4.0 global analysis of proton PDFs. Our work paves the way toward a full integrated global analysis of non-perturbative QCD -- a key ingredient for the exploitation of the scientific potential of present and future nuclear and particle physics facilities such as the Electron-Ion Collider (EIC).
[ { "created": "Wed, 12 Jul 2023 07:28:26 GMT", "version": "v1" } ]
2023-07-13
[ [ "Rabemananjara", "Tanjona", "" ] ]
We present progress towards a unified framework enabling the simultaneous determination of the parton distribution functions (PDFs) of the proton, deuteron, and nuclei up to lead $(^{208}\rm{Pb})$. Our approach is based on the integration of the fitting framework underlying the nNNPDF3.0 determination of nuclear PDFs into that adopted for the NNPDF4.0 global analysis of proton PDFs. Our work paves the way toward a full integrated global analysis of non-perturbative QCD -- a key ingredient for the exploitation of the scientific potential of present and future nuclear and particle physics facilities such as the Electron-Ion Collider (EIC).
2307.10380
Jiang-Hao Yu
Xu-Xiang Li, Zhe Ren, Jiang-Hao Yu
A complete tree-level dictionary between simplified BSM models and SMEFT (d $\leq$ 7) operators
55 pages, 1 figure, 12 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Finding all possible UV resonances of effective operators is an important task in the bottom-up approach of effective field theory. We present all the tree-level UV resonances for the dimension-5, -6 and -7 operators in the Standard Model effective field theory (SMEFT), and then obtain the correspondence between the UV resonances and the effective operators from the relations among their Wilson coefficients, through the functional matching and operator reduction procedure. This provides a cross-dimension UV/IR dictionary for the SMEFT at tree-level, and the methods used here, especially the on-shell construction of general UV Lagrangian and the systematic reduction of operators, are extendable for UV resonances of $d \geq 8$ operators in SMEFT and other EFTs.
[ { "created": "Wed, 19 Jul 2023 18:00:06 GMT", "version": "v1" } ]
2023-07-21
[ [ "Li", "Xu-Xiang", "" ], [ "Ren", "Zhe", "" ], [ "Yu", "Jiang-Hao", "" ] ]
Finding all possible UV resonances of effective operators is an important task in the bottom-up approach of effective field theory. We present all the tree-level UV resonances for the dimension-5, -6 and -7 operators in the Standard Model effective field theory (SMEFT), and then obtain the correspondence between the UV resonances and the effective operators from the relations among their Wilson coefficients, through the functional matching and operator reduction procedure. This provides a cross-dimension UV/IR dictionary for the SMEFT at tree-level, and the methods used here, especially the on-shell construction of general UV Lagrangian and the systematic reduction of operators, are extendable for UV resonances of $d \geq 8$ operators in SMEFT and other EFTs.
1409.1406
Debasish Borah
Debasish Borah and Arnab Dasgupta
Galactic Center Gamma Ray Excess in a Radiative Neutrino Mass Model
version 2: 18 pages, 6 figures, to appear in Physics Letters B
null
10.1016/j.physletb.2014.12.023
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Fermi gamma ray space telescope data have pointed towards an excess of gamma rays with a peak around $1-3$ GeV in the region surrounding the galactic center. This anomalous excess can be described well by a dark matter candidate having mass in the range $31-40$ GeV annihilating into $b\bar{b}$ pairs with a cross section of $< \sigma v > \simeq (1.4-2.0) \times 10^{-26} \; \text{cm}^3/\text{s}$. In this work we explore the possibility of having such a dark matter candidate within the framework of a radiative neutrino mass model. The model is a simple extension of the standard model by an additional $U(1)_X$ gauge symmetry where the standard model neutrino masses arise both at tree level as well as radiatively by the anomaly free addition of one singlet fermion $N_R$ and two triplet fermions $\Sigma_{1R}, \Sigma_{2R}$ with suitable Higgs scalars. The spontaneous gauge symmetry breaking is achieved in such a way which results in a residual $Z_2$ symmetry and hence providing a stable cold dark matter candidate. We show that the singlet fermionic dark matter candidate in our model can give rise to the galactic center gamma ray excess. The parameter space which simultaneously satisfy the constraints on relic density, direct detection scattering as well as collider bounds essentially corresponds to an s-wave resonance where the gauge boson mass $m_X$ is approximately twice that of dark matter mass $m_{\chi}$. We also discuss the compatibility of such a light fermion singlet dark matter with light neutrino mass.
[ { "created": "Thu, 4 Sep 2014 11:38:04 GMT", "version": "v1" }, { "created": "Mon, 8 Dec 2014 14:03:46 GMT", "version": "v2" } ]
2018-05-09
[ [ "Borah", "Debasish", "" ], [ "Dasgupta", "Arnab", "" ] ]
The Fermi gamma ray space telescope data have pointed towards an excess of gamma rays with a peak around $1-3$ GeV in the region surrounding the galactic center. This anomalous excess can be described well by a dark matter candidate having mass in the range $31-40$ GeV annihilating into $b\bar{b}$ pairs with a cross section of $< \sigma v > \simeq (1.4-2.0) \times 10^{-26} \; \text{cm}^3/\text{s}$. In this work we explore the possibility of having such a dark matter candidate within the framework of a radiative neutrino mass model. The model is a simple extension of the standard model by an additional $U(1)_X$ gauge symmetry where the standard model neutrino masses arise both at tree level as well as radiatively by the anomaly free addition of one singlet fermion $N_R$ and two triplet fermions $\Sigma_{1R}, \Sigma_{2R}$ with suitable Higgs scalars. The spontaneous gauge symmetry breaking is achieved in such a way which results in a residual $Z_2$ symmetry and hence providing a stable cold dark matter candidate. We show that the singlet fermionic dark matter candidate in our model can give rise to the galactic center gamma ray excess. The parameter space which simultaneously satisfy the constraints on relic density, direct detection scattering as well as collider bounds essentially corresponds to an s-wave resonance where the gauge boson mass $m_X$ is approximately twice that of dark matter mass $m_{\chi}$. We also discuss the compatibility of such a light fermion singlet dark matter with light neutrino mass.
hep-ph/0210426
Michael Klasen
Michael Klasen (Univ. Hamburg)
Calculating two- and three-body decays with FeynArts and FormCalc
8 pages, 1 figure
Int.J.Mod.Phys. C14 (2003) 1273-1278
10.1142/S012918310300539X
DESY 02-179
hep-ph
null
The Feynman diagram generator FeynArts and the computer algebra program FormCalc allow for an automatic computation of 2->2 and 2->3 scattering processes in High Energy Physics. We have extended this package by four new kinematical routines and adapted one existing routine in order to accomodate also two- and three-body decays of massive particles. This makes it possible to compute automatically two- and three-body particle decay widths and decay energy distributions as well as resonant particle production within the Standard Model and the Minimal Supersymmetric Standard Model at the tree- and loop-level. The use of the program is illustrated with three standard examples: h->b\bar{b}, \mu->e\bar{\nu}_e\nu_\mu, and Z->\nu_e\bar{\nu}_e.
[ { "created": "Wed, 30 Oct 2002 14:34:23 GMT", "version": "v1" } ]
2009-11-07
[ [ "Klasen", "Michael", "", "Univ. Hamburg" ] ]
The Feynman diagram generator FeynArts and the computer algebra program FormCalc allow for an automatic computation of 2->2 and 2->3 scattering processes in High Energy Physics. We have extended this package by four new kinematical routines and adapted one existing routine in order to accomodate also two- and three-body decays of massive particles. This makes it possible to compute automatically two- and three-body particle decay widths and decay energy distributions as well as resonant particle production within the Standard Model and the Minimal Supersymmetric Standard Model at the tree- and loop-level. The use of the program is illustrated with three standard examples: h->b\bar{b}, \mu->e\bar{\nu}_e\nu_\mu, and Z->\nu_e\bar{\nu}_e.
hep-ph/0102017
Marc Knecht
Marc Knecht (Centre de Physique Th\'eorique, CNRS-Luminy), Santiago Peris (Universitat Aut\`onoma de Barcelona) and E. de Rafael (Centre de Physique Th\'eorique, CNRS-Luminy)
A Critical Reassessment of Q7 and Q8 Matrix Elements
11 pages, latex; minor changes
Phys.Lett.B508:117-126,2001
10.1016/S0370-2693(01)00420-8
CPT-2001/P.4133, UAB-FT-508
hep-ph hep-lat
null
We compare recent theoretical determinations of weak matrix elements of the electroweak penguin operators Q7 and Q8. We pay special attention to the renormalization scheme dependence of these determinations as well as to the influence of higher dimension operators in the different approaches.
[ { "created": "Fri, 2 Feb 2001 12:52:58 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2001 14:50:19 GMT", "version": "v2" } ]
2016-08-16
[ [ "Knecht", "Marc", "", "Centre de Physique Théorique, CNRS-Luminy" ], [ "Peris", "Santiago", "", "Universitat Autònoma de Barcelona" ], [ "de Rafael", "E.", "", "Centre de\n Physique Théorique, CNRS-Luminy" ] ]
We compare recent theoretical determinations of weak matrix elements of the electroweak penguin operators Q7 and Q8. We pay special attention to the renormalization scheme dependence of these determinations as well as to the influence of higher dimension operators in the different approaches.
2305.12536
Wayne de Paula
A. Castro, W. de Paula, E. Ydrefors, T. Frederico, G. Salme
Exploring the $0^-$ bound state with dressed quarks in Minkowski space
null
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bethe-Salpeter equation for a pseudoscalar bound-system, with i) a ladder kernel with massive gluons, ii) dynamically-dressed quark mass function and iii) an extended quark-gluon vertex, is solved in Minkowski space by using the Nakanishi integral representation of the Bethe-Salpeter amplitude. The quark dressing is implemented through a phenomenological ansatz, which was tuned by lattice QCD calculations of the quark running mass. The latter were also used for assigning the range of the gluon mass and the parameter featuring the extended color density. This framework allows to investigate the gluon dynamics that manifest itself in the quark dressing, quark-gluon vertex and the binding, directly in the physical space. We present the first results for low-density pseudoscalar systems in order to elucidate the onset of the interplay between the above mentioned gluonic phenomena, and we discuss both static and dynamical quantities, like valence longitudinal and transverse distributions.
[ { "created": "Sun, 21 May 2023 18:38:18 GMT", "version": "v1" } ]
2023-05-23
[ [ "Castro", "A.", "" ], [ "de Paula", "W.", "" ], [ "Ydrefors", "E.", "" ], [ "Frederico", "T.", "" ], [ "Salme", "G.", "" ] ]
The Bethe-Salpeter equation for a pseudoscalar bound-system, with i) a ladder kernel with massive gluons, ii) dynamically-dressed quark mass function and iii) an extended quark-gluon vertex, is solved in Minkowski space by using the Nakanishi integral representation of the Bethe-Salpeter amplitude. The quark dressing is implemented through a phenomenological ansatz, which was tuned by lattice QCD calculations of the quark running mass. The latter were also used for assigning the range of the gluon mass and the parameter featuring the extended color density. This framework allows to investigate the gluon dynamics that manifest itself in the quark dressing, quark-gluon vertex and the binding, directly in the physical space. We present the first results for low-density pseudoscalar systems in order to elucidate the onset of the interplay between the above mentioned gluonic phenomena, and we discuss both static and dynamical quantities, like valence longitudinal and transverse distributions.
1807.08763
Christoph Englert
Christoph Englert, Peter Galler, Philip Harris, Michael Spannowsky
Machine Learning Uncertainties with Adversarial Neural Networks
10 pages, 6 figures, v2: published version
null
10.1140/epjc/s10052-018-6511-8
IPPP/18/61
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Machine Learning is a powerful tool to reveal and exploit correlations in a multi-dimensional parameter space. Making predictions from such correlations is a highly non-trivial task, in particular when the details of the underlying dynamics of a theoretical model are not fully understood. Using adversarial networks, we include a priori known sources of systematic and theoretical uncertainties during the training. This paves the way to a more reliable event classification on an event-by-event basis, as well as novel approaches to perform parameter fits of particle physics data. We demonstrate the benefits of the method explicitly in an example considering effective field theory extensions of Higgs boson production in association with jets.
[ { "created": "Mon, 23 Jul 2018 18:00:07 GMT", "version": "v1" }, { "created": "Thu, 3 Jan 2019 11:13:30 GMT", "version": "v2" } ]
2019-01-30
[ [ "Englert", "Christoph", "" ], [ "Galler", "Peter", "" ], [ "Harris", "Philip", "" ], [ "Spannowsky", "Michael", "" ] ]
Machine Learning is a powerful tool to reveal and exploit correlations in a multi-dimensional parameter space. Making predictions from such correlations is a highly non-trivial task, in particular when the details of the underlying dynamics of a theoretical model are not fully understood. Using adversarial networks, we include a priori known sources of systematic and theoretical uncertainties during the training. This paves the way to a more reliable event classification on an event-by-event basis, as well as novel approaches to perform parameter fits of particle physics data. We demonstrate the benefits of the method explicitly in an example considering effective field theory extensions of Higgs boson production in association with jets.
hep-ph/0412245
Celso Nishi
C. C. Nishi
Simple derivation of general Fierz-type identities
9pages. Few sentences modified in introduction and in conclusion. Typos corrected. An example added in introduction. Title modified
Am.J.Phys. 73 (2005) 1160-1163
10.1119/1.2074087
null
hep-ph hep-th physics.ed-ph
null
General Fierz-type identities are examined and their well known connection with completeness relations in matrix vector spaces is shown. In particular, I derive the chiral Fierz identities in a simple and systematic way by using a chiral basis for the complex $4\times4$ matrices. Other completeness relations for the fundamental representations of SU(N) algebras can be extracted using the same reasoning.
[ { "created": "Fri, 17 Dec 2004 07:29:45 GMT", "version": "v1" }, { "created": "Mon, 24 Jan 2005 18:51:18 GMT", "version": "v2" }, { "created": "Mon, 12 Sep 2005 22:02:42 GMT", "version": "v3" }, { "created": "Tue, 17 Jan 2006 18:54:35 GMT", "version": "v4" } ]
2009-11-10
[ [ "Nishi", "C. C.", "" ] ]
General Fierz-type identities are examined and their well known connection with completeness relations in matrix vector spaces is shown. In particular, I derive the chiral Fierz identities in a simple and systematic way by using a chiral basis for the complex $4\times4$ matrices. Other completeness relations for the fundamental representations of SU(N) algebras can be extracted using the same reasoning.
hep-ph/0012098
Susan Gardner
S. Gardner and C. Zhang
Sharpening Low-Energy, Standard-Model Tests via Correlation Coefficients in Neutron Beta-Decay
4 pages, REVTeX, intro. broadened, typos fixed, to appear in PRL
Phys.Rev.Lett.86:5666-5669,2001
10.1103/PhysRevLett.86.5666
null
hep-ph nucl-ex nucl-th
null
The correlation coefficients a, A, and B in neutron beta-decay are proportional to the ratio of the axial-vector to vector weak coupling constants, g_A/g_V, to leading recoil order. With the advent of the next generation of neutron decay experiments, the recoil-order corrections to these expressions become experimentally accessible, admitting a plurality of Standard Model (SM) tests. The measurement of both a and A, e.g., allows one to test the conserved-vector-current (CVC) hypothesis and to search for second-class currents (SCC) independently. The anticipated precision of these measurements suggests that the bounds on CVC violation and SCC from studies of nuclear beta-decay can be qualitatively bettered. Departures from SM expectations can be interpreted as evidence for non-V-A currents.
[ { "created": "Fri, 8 Dec 2000 18:18:58 GMT", "version": "v1" }, { "created": "Sun, 10 Dec 2000 17:55:27 GMT", "version": "v2" }, { "created": "Mon, 30 Apr 2001 18:02:06 GMT", "version": "v3" } ]
2008-11-26
[ [ "Gardner", "S.", "" ], [ "Zhang", "C.", "" ] ]
The correlation coefficients a, A, and B in neutron beta-decay are proportional to the ratio of the axial-vector to vector weak coupling constants, g_A/g_V, to leading recoil order. With the advent of the next generation of neutron decay experiments, the recoil-order corrections to these expressions become experimentally accessible, admitting a plurality of Standard Model (SM) tests. The measurement of both a and A, e.g., allows one to test the conserved-vector-current (CVC) hypothesis and to search for second-class currents (SCC) independently. The anticipated precision of these measurements suggests that the bounds on CVC violation and SCC from studies of nuclear beta-decay can be qualitatively bettered. Departures from SM expectations can be interpreted as evidence for non-V-A currents.
1507.04059
Martin Hentschinski
M. Hentschinski
The perturbative Pomeron with NLO accuracy: Jet-Gap-Jet Observables
6 pages; Proceedings of the XXIII International Workshop on Deep-Inelastic Scattering, 27 April - May 1 2015, Dallas, Texas
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give an overview of the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to a jet) in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism at next-to-leading order (NLO). This result allows, together with the NLO non-forward gluon Green function, to perform NLO studies of jet production in diffractive events (Mueller-Tang dijets, as a well-known example)
[ { "created": "Wed, 15 Jul 2015 00:47:44 GMT", "version": "v1" } ]
2015-07-16
[ [ "Hentschinski", "M.", "" ] ]
We give an overview of the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to a jet) in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism at next-to-leading order (NLO). This result allows, together with the NLO non-forward gluon Green function, to perform NLO studies of jet production in diffractive events (Mueller-Tang dijets, as a well-known example)
1606.00342
Niklas Mueller
Niklas Mueller, S\"oren Schlichting, Sayantan Sharma
Chiral magnetic effect and anomalous transport from real-time lattice simulations
5 pages, 3 figures, references updated, journal version
Phys. Rev. Lett. 117, 142301 (2016)
10.1103/PhysRevLett.117.142301
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a first-principle study of anomaly induced transport phenomena by performing real-time lattice simulations with dynamical fermions coupled simultaneously to non-Abelian $SU(N_c)$ and Abelian $U(1)$ gauge fields. Investigating the behavior of vector and axial currents during a sphaleron transition in the presence of an external magnetic field, we demonstrate how the interplay of the Chiral magnetic (CME) and Chiral separation effect (CSE) lead to the formation of a propagating wave. We further analyze the dependence of the magnitude of the induced vector current and the propagation of the wave on the amount of explicit chiral symmetry breaking due to finite quark mass.
[ { "created": "Wed, 1 Jun 2016 16:06:41 GMT", "version": "v1" }, { "created": "Mon, 26 Sep 2016 08:27:56 GMT", "version": "v2" } ]
2016-10-05
[ [ "Mueller", "Niklas", "" ], [ "Schlichting", "Sören", "" ], [ "Sharma", "Sayantan", "" ] ]
We present a first-principle study of anomaly induced transport phenomena by performing real-time lattice simulations with dynamical fermions coupled simultaneously to non-Abelian $SU(N_c)$ and Abelian $U(1)$ gauge fields. Investigating the behavior of vector and axial currents during a sphaleron transition in the presence of an external magnetic field, we demonstrate how the interplay of the Chiral magnetic (CME) and Chiral separation effect (CSE) lead to the formation of a propagating wave. We further analyze the dependence of the magnitude of the induced vector current and the propagation of the wave on the amount of explicit chiral symmetry breaking due to finite quark mass.
hep-ph/9905245
Dipanwita Dutta
D. Dutta, K. Kumar, A. K. Mohanty and R. K. Choudhury (Nuclear Physics Division, Bhabha Atomic Research Centre, India)
Chemical equilibration and thermal dilepton production from the quark gluon plasma at finite baryon density
Latex, 19 pages, 8 postscript figures. To appear in Phys. Rev. C
Phys.Rev. C60 (1999) 014905
10.1103/PhysRevC.60.014905
null
hep-ph
null
The chemical equilibration of a highly unsaturated quark-gluon plasma has been studied at finite baryon density. It is found that in the presence of small amount of baryon density, the chemical equilibration for gluon becomes slower and the temperature decreases less steeply as compared to the baryon free plasma. As a result, the space time integrated yield of dilepton is enhanced if the initial temperature of the plasma is held fixed. Even at a fixed initial energy density, the suppression of the dilepton yields at higher baryo-chemical potential is compensated, to a large extent, by the slow cooling of the plasma.
[ { "created": "Wed, 5 May 1999 08:16:50 GMT", "version": "v1" } ]
2009-10-31
[ [ "Dutta", "D.", "", "Nuclear Physics\n Division, Bhabha Atomic Research Centre, India" ], [ "Kumar", "K.", "", "Nuclear Physics\n Division, Bhabha Atomic Research Centre, India" ], [ "Mohanty", "A. K.", "", "Nuclear Physics\n Division, Bhabha Atomic Research Centre, India" ], [ "Choudhury", "R. K.", "", "Nuclear Physics\n Division, Bhabha Atomic Research Centre, India" ] ]
The chemical equilibration of a highly unsaturated quark-gluon plasma has been studied at finite baryon density. It is found that in the presence of small amount of baryon density, the chemical equilibration for gluon becomes slower and the temperature decreases less steeply as compared to the baryon free plasma. As a result, the space time integrated yield of dilepton is enhanced if the initial temperature of the plasma is held fixed. Even at a fixed initial energy density, the suppression of the dilepton yields at higher baryo-chemical potential is compensated, to a large extent, by the slow cooling of the plasma.
1909.02978
Xiao Wang
Xiao Wang, Fa Peng Huang, Xinmin Zhang
Gravitational wave and collider signals in complex two-Higgs doublet model with dynamical CP-violation at finite temperature
Published version in Physical Review D, 35 pages, 9 figures, 7 tables
Phys. Rev. D 101, 015015 (2020)
10.1103/PhysRevD.101.015015
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extra CP-violating source for electroweak baryogenesis can dynamically appear at finite temperature in the complex two-Higgs doublet model, which might help to alleviate the strong constraints from the electric dipole moment experiments. In this scenario, we study the detailed phase transition dynamics and the corresponding gravitational wave signals in synergy with the collider signals at future lepton colliders. For some parameter spaces, various phase transition patterns can occur, such as the multi-step phase transition and supercooling. Gravitational waves complementary to collider signals can help to pin down the underlying phase transition dynamics or different phase transition patterns.
[ { "created": "Fri, 6 Sep 2019 15:42:34 GMT", "version": "v1" }, { "created": "Mon, 13 Jan 2020 05:01:22 GMT", "version": "v2" }, { "created": "Mon, 27 Jan 2020 15:31:38 GMT", "version": "v3" } ]
2020-01-28
[ [ "Wang", "Xiao", "" ], [ "Huang", "Fa Peng", "" ], [ "Zhang", "Xinmin", "" ] ]
Extra CP-violating source for electroweak baryogenesis can dynamically appear at finite temperature in the complex two-Higgs doublet model, which might help to alleviate the strong constraints from the electric dipole moment experiments. In this scenario, we study the detailed phase transition dynamics and the corresponding gravitational wave signals in synergy with the collider signals at future lepton colliders. For some parameter spaces, various phase transition patterns can occur, such as the multi-step phase transition and supercooling. Gravitational waves complementary to collider signals can help to pin down the underlying phase transition dynamics or different phase transition patterns.
1110.2123
Brett D. Altschul
Brett Altschul
Consequences of Neutrino Lorentz Violation For Leptonic Meson Decays
10 pages
Phys. Rev. D 84, 091902(R) (2011)
10.1103/PhysRevD.84.091902
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If the observation by OPERA of apparently superluminal neutrinos is correct, the Lagrangian for second-generation leptons must break Lorentz invariance. We calculate the effects of an energy-independent change in the neutrino speed on another observable, the charged pion decay rate. The rate decreases by an factor [1 - 3/(1 - (m_mu)^2 / (m_pi) ^ 2) (< v_(nu) > - 1)], where < v_(nu) > is the (directionally averaged) neutrino speed in the pion's rest frame. This provides a completely independent experimental observable that is sensitive to the same forms of Lorentz violation as a neutrino time of flight measurement.
[ { "created": "Mon, 10 Oct 2011 17:59:25 GMT", "version": "v1" }, { "created": "Mon, 14 Nov 2011 17:17:38 GMT", "version": "v2" } ]
2011-11-15
[ [ "Altschul", "Brett", "" ] ]
If the observation by OPERA of apparently superluminal neutrinos is correct, the Lagrangian for second-generation leptons must break Lorentz invariance. We calculate the effects of an energy-independent change in the neutrino speed on another observable, the charged pion decay rate. The rate decreases by an factor [1 - 3/(1 - (m_mu)^2 / (m_pi) ^ 2) (< v_(nu) > - 1)], where < v_(nu) > is the (directionally averaged) neutrino speed in the pion's rest frame. This provides a completely independent experimental observable that is sensitive to the same forms of Lorentz violation as a neutrino time of flight measurement.
2303.01534
Ryan Wood
Andrea Banfi, Basem Kamal El-Menoufi, Ryan Wood
Interplay between perturbative and non-perturbative effects with the ARES method
The revised version contains an additional figure and provides further clarifications
JHEP 08 (2023) 221
10.1007/JHEP08(2023)221
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new semi-numerical method to compute leading hadronisation corrections to two-jet event shapes in $e^+e^-$ annihilation. The formalism we present utilises the dispersive approach, where the magnitude of power corrections is controlled by suitable moments of an effective strong coupling, but it can be adapted to other methods. We focus on observables where the interplay between perturbative and non-perturbative effects is crucial in determining the power corrections. A naive treatment of power corrections for some of these observables gives rise to an unphysical behaviour in the corresponding distributions for moderate observable values, thus considerably limiting the available range to fit the non-perturbative moments. We present a universal treatment to handle such observables, based on a suitable subtraction procedure, and compare our results to the analytic result in the case of total broadening. Finally, for the first time we present predictions for the thrust major, which cannot be handled with analytic methods.
[ { "created": "Thu, 2 Mar 2023 19:01:17 GMT", "version": "v1" }, { "created": "Tue, 5 Sep 2023 18:41:47 GMT", "version": "v2" } ]
2023-09-07
[ [ "Banfi", "Andrea", "" ], [ "El-Menoufi", "Basem Kamal", "" ], [ "Wood", "Ryan", "" ] ]
We present a new semi-numerical method to compute leading hadronisation corrections to two-jet event shapes in $e^+e^-$ annihilation. The formalism we present utilises the dispersive approach, where the magnitude of power corrections is controlled by suitable moments of an effective strong coupling, but it can be adapted to other methods. We focus on observables where the interplay between perturbative and non-perturbative effects is crucial in determining the power corrections. A naive treatment of power corrections for some of these observables gives rise to an unphysical behaviour in the corresponding distributions for moderate observable values, thus considerably limiting the available range to fit the non-perturbative moments. We present a universal treatment to handle such observables, based on a suitable subtraction procedure, and compare our results to the analytic result in the case of total broadening. Finally, for the first time we present predictions for the thrust major, which cannot be handled with analytic methods.
hep-ph/0004052
A. Kovner
C.P. Korthals Altes (CPT, Marseille) and A. Kovner (Oxford U.)
Magnetic Z(N) symmetry in hot QCD and the spatial Wilson loop
30 pages, discussion of the Wilson loop at high temperature completely revised, new references added
Phys.Rev. D62 (2000) 096008
10.1103/PhysRevD.62.096008
OUTP-0013 P, CPT-P.3998
hep-ph
null
We discuss the relation between the deconfining phase transition in gauge theories and the realization of the magnetic Z(N) symmetry. At low temperature the Z(N) symmetry is spontaneously broken while above the phase transition it is restored. This is intimately related to the change of behaviour of the spatial 't Hooft loop discussed in hep-ph/9909516. We also point out that the realization of the magnetic symmetry has bearing on the behaviour of the spatial Wilson loop. We give a physical argument to the effect that at zero temperature the spatial Wilson loop must have perimeter law behaviour in the symmetric phase but area law behaviour in the spontaneously broken phase. At high temperature the argument does not hold and the restoration of magnetic Z(N) is consistent with area law for the Wilson loop.
[ { "created": "Thu, 6 Apr 2000 11:32:28 GMT", "version": "v1" }, { "created": "Fri, 26 May 2000 16:26:11 GMT", "version": "v2" } ]
2009-10-31
[ [ "Altes", "C. P. Korthals", "", "CPT, Marseille" ], [ "Kovner", "A.", "", "Oxford U." ] ]
We discuss the relation between the deconfining phase transition in gauge theories and the realization of the magnetic Z(N) symmetry. At low temperature the Z(N) symmetry is spontaneously broken while above the phase transition it is restored. This is intimately related to the change of behaviour of the spatial 't Hooft loop discussed in hep-ph/9909516. We also point out that the realization of the magnetic symmetry has bearing on the behaviour of the spatial Wilson loop. We give a physical argument to the effect that at zero temperature the spatial Wilson loop must have perimeter law behaviour in the symmetric phase but area law behaviour in the spontaneously broken phase. At high temperature the argument does not hold and the restoration of magnetic Z(N) is consistent with area law for the Wilson loop.
hep-ph/0203132
Alexandre Rozanov
V.A. Novikov, L.B. Okun, A.N. Rozanov, M.I. Vysotsky
Mass of the higgs versus fourth generation masses
8 pages, 4 figures
JETP Lett.76:127-130,2002; Pisma Zh.Eksp.Teor.Fiz.76:158-161,2002
10.1134/1.1514752
null
hep-ph
null
The predicted value of the higgs mass $m_H$ is analyzed assuming the existence of the fourth generation of leptons ($N, E$) and quarks ($U, D$). The steep and flat directions are found in the five-dimensional parameter space: $m_H$, $m_U$, $m_D$, $m_N$, $m_E$. The LEPTOP fit of the precision electroweak data is compatible (in particular) with $m_H \sim 300$ GeV, $m_N \sim 50$ GeV, $m_E \sim 100$ GeV, $m_U +m_D \sim 500$ GeV, and $|m_U -m_D| \sim 75$ GeV. The quality of fits drastically improves when the data on b- and c-quark asymmetries and new NuTeV data on deep inelastic scattering are ignored.
[ { "created": "Thu, 14 Mar 2002 12:03:52 GMT", "version": "v1" }, { "created": "Mon, 15 Jul 2002 21:34:41 GMT", "version": "v2" } ]
2011-01-25
[ [ "Novikov", "V. A.", "" ], [ "Okun", "L. B.", "" ], [ "Rozanov", "A. N.", "" ], [ "Vysotsky", "M. I.", "" ] ]
The predicted value of the higgs mass $m_H$ is analyzed assuming the existence of the fourth generation of leptons ($N, E$) and quarks ($U, D$). The steep and flat directions are found in the five-dimensional parameter space: $m_H$, $m_U$, $m_D$, $m_N$, $m_E$. The LEPTOP fit of the precision electroweak data is compatible (in particular) with $m_H \sim 300$ GeV, $m_N \sim 50$ GeV, $m_E \sim 100$ GeV, $m_U +m_D \sim 500$ GeV, and $|m_U -m_D| \sim 75$ GeV. The quality of fits drastically improves when the data on b- and c-quark asymmetries and new NuTeV data on deep inelastic scattering are ignored.
hep-ph/9308351
null
A. Pich
Introduction to Chiral Perturbation Theory
46 pages, 4 figures (appended at the end), CERN-TH.6978/93
AIP Conf.Proc.317:95-140,1994
10.1063/1.46859
null
hep-ph
null
An introduction to the basic ideas and methods of Chiral Perturbation Theory is presented. Several phenomenological applications of the effective Lagrangian technique to strong, electromagnetic and weak interactions are discussed.
[ { "created": "Fri, 27 Aug 1993 16:23:17 GMT", "version": "v1" } ]
2015-06-25
[ [ "Pich", "A.", "" ] ]
An introduction to the basic ideas and methods of Chiral Perturbation Theory is presented. Several phenomenological applications of the effective Lagrangian technique to strong, electromagnetic and weak interactions are discussed.
2105.13805
Lianbao Jia
Lian-Bao Jia
Dark leptophilic scalar with the updated muon $g-2$ anomaly
5 pages, 4 figures, discussions added, version accepted by EPJC
null
10.1140/epjc/s10052-022-10207-1
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
The muon $g-2$ anomaly was strengthened by recent experimental results at Fermilab, which may be signatures of new physics. A scenario of leptophilic scalar $\phi_L$ accounting for the muon $g-2$ anomaly is investigated in this paper. Though a light $\phi_L$ mainly decaying into standard model (SM) particles has been excluded by experiments, a dark leptophilic scalar $\phi_L$ predominantly decaying into invisible fermionic dark matter (DM) $\chi \bar{\chi}$ is still allowed. Considering the decay mode $\phi_L \to \chi \bar{\chi}$ opened (here $m_{\phi_L} = 3 m_\chi$), the coupling preferred by the muon $g-2$ and the $\phi_L-\chi$ coupling are derived. The light/heavy $\phi_L$ (roughly 1 GeV as a benchmark value) can be tested by future experiments via DM/SM decay modes, and $\phi_L$'s contribution to the anomalous magnetic moment of tau lepton could be investigated at lepton colliders. The search of $\chi$ via $\chi-$electron scattering in DM direct detection is not sensitive due to a tiny $\phi_L-$electron coupling, especially for $m_\chi \gtrsim m_\mu$.
[ { "created": "Fri, 28 May 2021 13:22:11 GMT", "version": "v1" }, { "created": "Tue, 15 Mar 2022 04:19:00 GMT", "version": "v2" } ]
2022-04-27
[ [ "Jia", "Lian-Bao", "" ] ]
The muon $g-2$ anomaly was strengthened by recent experimental results at Fermilab, which may be signatures of new physics. A scenario of leptophilic scalar $\phi_L$ accounting for the muon $g-2$ anomaly is investigated in this paper. Though a light $\phi_L$ mainly decaying into standard model (SM) particles has been excluded by experiments, a dark leptophilic scalar $\phi_L$ predominantly decaying into invisible fermionic dark matter (DM) $\chi \bar{\chi}$ is still allowed. Considering the decay mode $\phi_L \to \chi \bar{\chi}$ opened (here $m_{\phi_L} = 3 m_\chi$), the coupling preferred by the muon $g-2$ and the $\phi_L-\chi$ coupling are derived. The light/heavy $\phi_L$ (roughly 1 GeV as a benchmark value) can be tested by future experiments via DM/SM decay modes, and $\phi_L$'s contribution to the anomalous magnetic moment of tau lepton could be investigated at lepton colliders. The search of $\chi$ via $\chi-$electron scattering in DM direct detection is not sensitive due to a tiny $\phi_L-$electron coupling, especially for $m_\chi \gtrsim m_\mu$.
2110.09883
Xun-Jie Xu
Marco Hufnagel, Xun-Jie Xu
Dark matter produced from neutrinos
29 pages, 8 figures
null
10.1088/1475-7516/2022/01/043
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
In the presence of interactions between neutrinos and dark matter (DM), DM can potentially be produced via freeze-in from the neutrino sector. We investigate the implications of such a scenario for the evolution of both DM and neutrinos in the early Universe, and show that the future cosmic neutrino detection experiment PTOLEMY might be sensitive to neutrino signals that originate from DM annihilation in this model.
[ { "created": "Tue, 19 Oct 2021 11:56:52 GMT", "version": "v1" } ]
2022-02-02
[ [ "Hufnagel", "Marco", "" ], [ "Xu", "Xun-Jie", "" ] ]
In the presence of interactions between neutrinos and dark matter (DM), DM can potentially be produced via freeze-in from the neutrino sector. We investigate the implications of such a scenario for the evolution of both DM and neutrinos in the early Universe, and show that the future cosmic neutrino detection experiment PTOLEMY might be sensitive to neutrino signals that originate from DM annihilation in this model.
1811.00017
Daniel Egana-Ugrinovic
Daniel Egana-Ugrinovic, Samuel Homiller and Patrick Meade
Aligned and Spontaneous Flavor Violation
7 pages, 1 figure
Phys. Rev. Lett. 123, 031802 (2019)
10.1103/PhysRevLett.123.031802
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a systematic spurion setup called Aligned Flavor Violation (AFV) that allows for new physics couplings to quarks that are aligned with the Standard Model (SM) Yukawas, but do not necessarily share their hierarchies nor are family universal. Additionally, we show that there is an important subset of AFV called Spontaneous Flavor Violation (SFV), which naturally arises from UV completions where the quark family number and CP groups are spontaneously broken. Flavor-changing neutral currents are strongly suppressed in SFV extensions of the SM. We study SFV from an effective field theory perspective and demonstrate that SFV new physics with significant and preferential couplings to first or second generation quarks may be close to the TeV scale.
[ { "created": "Wed, 31 Oct 2018 18:00:01 GMT", "version": "v1" } ]
2019-07-24
[ [ "Egana-Ugrinovic", "Daniel", "" ], [ "Homiller", "Samuel", "" ], [ "Meade", "Patrick", "" ] ]
We present a systematic spurion setup called Aligned Flavor Violation (AFV) that allows for new physics couplings to quarks that are aligned with the Standard Model (SM) Yukawas, but do not necessarily share their hierarchies nor are family universal. Additionally, we show that there is an important subset of AFV called Spontaneous Flavor Violation (SFV), which naturally arises from UV completions where the quark family number and CP groups are spontaneously broken. Flavor-changing neutral currents are strongly suppressed in SFV extensions of the SM. We study SFV from an effective field theory perspective and demonstrate that SFV new physics with significant and preferential couplings to first or second generation quarks may be close to the TeV scale.
hep-ph/9612389
Michael Dine
Michael Dine
Supersymmetry Phenomenology With a Broad Brush
67 pages including figures, latex
null
null
SCIPP 96/73
hep-ph
null
These lectures provide an introduction to supersymmetry phenomenology. They include an overview of the Minimal Supersymmetric Standard Model. The notion of soft breaking is explained, constraints on the standard soft breaking parameters are reviewed, and the standard ansatz of universal soft masses is discussed. The rest of the lectures are devoted to understanding supersymmetry breaking more microscopically. Models of dynamical supersymmetry breaking are reviewed, after which we turn to the question of the scale of supersymmetry breaking. Both intermediate and low scales and their phenomenology are considered. Finally, we consider applications to string theory. The emphasis, throughout, is on general issues rather then extensive detail, but it is hoped that the listeners/readers will be prepared after these lectures to delve into the details.
[ { "created": "Tue, 17 Dec 1996 18:01:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dine", "Michael", "" ] ]
These lectures provide an introduction to supersymmetry phenomenology. They include an overview of the Minimal Supersymmetric Standard Model. The notion of soft breaking is explained, constraints on the standard soft breaking parameters are reviewed, and the standard ansatz of universal soft masses is discussed. The rest of the lectures are devoted to understanding supersymmetry breaking more microscopically. Models of dynamical supersymmetry breaking are reviewed, after which we turn to the question of the scale of supersymmetry breaking. Both intermediate and low scales and their phenomenology are considered. Finally, we consider applications to string theory. The emphasis, throughout, is on general issues rather then extensive detail, but it is hoped that the listeners/readers will be prepared after these lectures to delve into the details.
1812.09828
Wieslaw Sobk\'ow
A. B{\l}aut and W. Sobk\'ow
Neutrino elastic scattering on polarized electrons as a tool for probing the neutrino nature
10 pages, 10 figures, published version
Eur. Phys. J. C (2020) 80:261
10.1140/epjc/s10052-020-7806-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Possibility of using the polarized electron target (PET) for testing the neutrino nature is considered. One assumes that the incoming electron neutrino ($\nu_e$) beam is the superposition of left chiral states with right chiral ones. Consequently the non-vanishing transversal components of $\nu_e$ spin polarization may appear, both T-even and T-odd. $\nu_e$s are produced by the low energy monochromatic (un)polarized emitter located at a near distance from the hypothetical detector which is able to measure both the azimuthal angle and polar angle of the recoil electrons, and/or also the energy of the outgoing electrons with a high resolution. A detection process is the elastic scattering of $\nu_e$s (Dirac or Majorana) on the polarized electrons. Left chiral (LC) $\nu_e$s interact mainly by the standard $V - A$ interaction, while right chiral (RC) ones participate only in the non-standard $V + A$, scalar $S_R$, pseudoscalar $P_R$ and tensor $T_R$ interactions. All the interactions are of flavour-conserving type (FC). We show that a distinction between the Dirac and the Majorana $\nu_e$ s is possible both for the longitudinal and the transversal $\nu_e$ polarizations. In the first case a departure from the standard prediction of the azimuthal asymmetry of recoil electrons is caused by the interferences between the non-standard complex S and T couplings. Such a deviation would indicate the Dirac $\nu_e$ nature and the presence of time reversal symmetry violation (TRSV) interactions. In the second case the azimuthal asymmetries, polar distribution and energy spectrum of scattered electrons are sensitive to the interference terms between the standard and exotic interactions, proportional to the various angular correlations. Our model-independent study is carried out for the flavour $\nu_e$ eigenstates in the relativistic $\nu_e$ limit.
[ { "created": "Mon, 24 Dec 2018 04:31:43 GMT", "version": "v1" }, { "created": "Tue, 5 May 2020 10:51:28 GMT", "version": "v2" } ]
2020-05-06
[ [ "Błaut", "A.", "" ], [ "Sobków", "W.", "" ] ]
Possibility of using the polarized electron target (PET) for testing the neutrino nature is considered. One assumes that the incoming electron neutrino ($\nu_e$) beam is the superposition of left chiral states with right chiral ones. Consequently the non-vanishing transversal components of $\nu_e$ spin polarization may appear, both T-even and T-odd. $\nu_e$s are produced by the low energy monochromatic (un)polarized emitter located at a near distance from the hypothetical detector which is able to measure both the azimuthal angle and polar angle of the recoil electrons, and/or also the energy of the outgoing electrons with a high resolution. A detection process is the elastic scattering of $\nu_e$s (Dirac or Majorana) on the polarized electrons. Left chiral (LC) $\nu_e$s interact mainly by the standard $V - A$ interaction, while right chiral (RC) ones participate only in the non-standard $V + A$, scalar $S_R$, pseudoscalar $P_R$ and tensor $T_R$ interactions. All the interactions are of flavour-conserving type (FC). We show that a distinction between the Dirac and the Majorana $\nu_e$ s is possible both for the longitudinal and the transversal $\nu_e$ polarizations. In the first case a departure from the standard prediction of the azimuthal asymmetry of recoil electrons is caused by the interferences between the non-standard complex S and T couplings. Such a deviation would indicate the Dirac $\nu_e$ nature and the presence of time reversal symmetry violation (TRSV) interactions. In the second case the azimuthal asymmetries, polar distribution and energy spectrum of scattered electrons are sensitive to the interference terms between the standard and exotic interactions, proportional to the various angular correlations. Our model-independent study is carried out for the flavour $\nu_e$ eigenstates in the relativistic $\nu_e$ limit.
1411.4876
Stella Riad
Johannes Bergstrom and Stella Riad
Bayesian Model comparison of Higgs couplings
24 pages, 4 figures
Phys. Rev. D 91, 075008 (2015)
10.1103/PhysRevD.91.075008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility of contributions from physics beyond the Standard Model (SM) to the Higgs couplings, in the light of the LHC data. The work is performed within an interim framework where the magnitude of the Higgs production and decay rates are rescaled though Higgs coupling scale factors. We perform Bayesian parameter inference on these scale factors, concluding that there is good compatibility with the SM. Furthermore, we carry out Bayesian model comparison on all models where any combination of scale factors can differ from their SM values and find that typically models with fewer free couplings are strongly favoured. We consider the evidence that each coupling individually equals the SM value, making the minimal assumptions on the other couplings. Finally, we make a comparison of the SM against a single "not-SM" model, and find that there is moderate to strong evidence for the SM.
[ { "created": "Tue, 18 Nov 2014 15:36:16 GMT", "version": "v1" }, { "created": "Thu, 1 Oct 2015 10:07:12 GMT", "version": "v2" } ]
2015-10-02
[ [ "Bergstrom", "Johannes", "" ], [ "Riad", "Stella", "" ] ]
We investigate the possibility of contributions from physics beyond the Standard Model (SM) to the Higgs couplings, in the light of the LHC data. The work is performed within an interim framework where the magnitude of the Higgs production and decay rates are rescaled though Higgs coupling scale factors. We perform Bayesian parameter inference on these scale factors, concluding that there is good compatibility with the SM. Furthermore, we carry out Bayesian model comparison on all models where any combination of scale factors can differ from their SM values and find that typically models with fewer free couplings are strongly favoured. We consider the evidence that each coupling individually equals the SM value, making the minimal assumptions on the other couplings. Finally, we make a comparison of the SM against a single "not-SM" model, and find that there is moderate to strong evidence for the SM.
hep-ph/9911414
null
B.A. Kniehl and A.A. Penin (Hamburg University)
Order alpha_s^3 ln^2(1/alpha_s) Corrections to Heavy-Quarkonium Creation and Annihilation
14 pages (Latex), 1 figures (Axodraw); text slightly extended, a few typos corrected, three references added; accepted for publication in Nucl. Phys. B
Nucl.Phys. B577 (2000) 197-208
10.1016/S0550-3213(00)00139-5
DESY 99-173
hep-ph
null
In the framework of nonrelativistic QCD, we compute the leading double-logarithmic corrections of order alpha_s^3 ln^2(1/alpha_s) to the heavy-quark-antiquark bound-state wave function at the origin, which determines the production and annihilation rates of heavy quarkonia. The phenomenological implications for the top-antitop and Upsilon systems are discussed.
[ { "created": "Fri, 19 Nov 1999 17:42:33 GMT", "version": "v1" }, { "created": "Sat, 20 Nov 1999 15:20:36 GMT", "version": "v2" }, { "created": "Tue, 29 Feb 2000 15:44:44 GMT", "version": "v3" } ]
2009-10-31
[ [ "Kniehl", "B. A.", "", "Hamburg University" ], [ "Penin", "A. A.", "", "Hamburg University" ] ]
In the framework of nonrelativistic QCD, we compute the leading double-logarithmic corrections of order alpha_s^3 ln^2(1/alpha_s) to the heavy-quark-antiquark bound-state wave function at the origin, which determines the production and annihilation rates of heavy quarkonia. The phenomenological implications for the top-antitop and Upsilon systems are discussed.
hep-ph/0103162
Yoshiaki Koma Nuclear Science Group
Y. Koma, E. -M. Ilgenfritz, H. Toki, and T. Suzuki
Casimir scaling in a dual superconducting scenario of confinement
14 pages, 3 eps figures, RevTex. The version accepted for publication in Phys.Rev.D (Rapid Communications)
Phys.Rev.D64:011501,2001
10.1103/PhysRevD.64.011501
RCNP-Th/01006
hep-ph hep-lat
null
The string tensions of flux tubes associated with static charges in various SU(3) representations are studied within the dual Ginzburg-Landau (DGL) theory. The ratios of the string tensions between higher and fundamental representations, $d_{D} \equiv \sigma_{D}/\sigma_{F}$, are found to depend only on the Ginzburg-Landau (GL) parameter, $\kappa = m_{\chi}/m_{B}$, the mass ratio between monopoles $m_\chi$ and dual gauge bosons $m_B$. In the case of the Bogomol'nyi limit ($\kappa=1$), analytical values of $d_{D}$ are easily obtained by adopting the manifestly Weyl invariant formulation of the DGL theory, which are provided simply by the number of color-electric Dirac strings inside the flux tube. A numerical investigation of the ratio for various GL-parameter cases is also performed, which suggests that the Casimir scaling is obtained in the type-II parameter range within the interval $\kappa=5 \sim 9$ for various ratios $d_D$.
[ { "created": "Wed, 14 Mar 2001 15:50:35 GMT", "version": "v1" }, { "created": "Thu, 26 Apr 2001 06:19:13 GMT", "version": "v2" } ]
2009-12-31
[ [ "Koma", "Y.", "" ], [ "Ilgenfritz", "E. -M.", "" ], [ "Toki", "H.", "" ], [ "Suzuki", "T.", "" ] ]
The string tensions of flux tubes associated with static charges in various SU(3) representations are studied within the dual Ginzburg-Landau (DGL) theory. The ratios of the string tensions between higher and fundamental representations, $d_{D} \equiv \sigma_{D}/\sigma_{F}$, are found to depend only on the Ginzburg-Landau (GL) parameter, $\kappa = m_{\chi}/m_{B}$, the mass ratio between monopoles $m_\chi$ and dual gauge bosons $m_B$. In the case of the Bogomol'nyi limit ($\kappa=1$), analytical values of $d_{D}$ are easily obtained by adopting the manifestly Weyl invariant formulation of the DGL theory, which are provided simply by the number of color-electric Dirac strings inside the flux tube. A numerical investigation of the ratio for various GL-parameter cases is also performed, which suggests that the Casimir scaling is obtained in the type-II parameter range within the interval $\kappa=5 \sim 9$ for various ratios $d_D$.
0910.3181
Peter Schweitzer
H.Avakian, A.V.Efremov, P.Schweitzer, O.V.Teryaev, F.Yuan, P.Zavada
Insights on non-perturbative aspects of TMDs from models
Based on talks at "Transverse Partonic Structure of Hadrons", Yerevan, Armenia, 21-26 June 2009; "Recent Advances in Perturbative QCD and Hadronic Physics", ETC, Trento, Italy, 21-25 July 2009; "3D parton structure of the nucleon"," INT Seattle, WA, U.S.A. 14-18 September 2009. Dedicated to 75th birthday of A.V.Efremov by co-authors
Mod.Phys.Lett.A24:2995-3004,2009
10.1142/S0217732309001200
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse momentum dependent parton distribution functions are a key ingredient in the description of spin and azimuthal asymmetries in deep-inelastic scattering processes. Recent results from non-perturbative calculations in effective approaches are reviewed, with focus on relations among different parton distribution functions in QCD and models.
[ { "created": "Fri, 16 Oct 2009 18:32:48 GMT", "version": "v1" } ]
2010-02-04
[ [ "Avakian", "H.", "" ], [ "Efremov", "A. V.", "" ], [ "Schweitzer", "P.", "" ], [ "Teryaev", "O. V.", "" ], [ "Yuan", "F.", "" ], [ "Zavada", "P.", "" ] ]
Transverse momentum dependent parton distribution functions are a key ingredient in the description of spin and azimuthal asymmetries in deep-inelastic scattering processes. Recent results from non-perturbative calculations in effective approaches are reviewed, with focus on relations among different parton distribution functions in QCD and models.
0802.2579
FengLan Shao
Yun-fei Wang, Feng-lan Shao, Jun Song, De-ming Wei, Qu-bing Xie
Centrality dependence of $p_{T}$ spectra for identified hadrons in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}= 200$ GeV
7 pages, 6 figures
Chinese Physics C32, 976 (2008)
10.1088/1674-1137/32/12/007
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The centrality dependence of transverse momentum spectra for identified hadrons at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}= 200$ GeV is systematically studied in a quark combination model. The $\mathrm{{p}_{T}}$ spectra of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ and $\Lambda(\bar{\Lambda})$ in different centrality bins and the nuclear modification factors ($R_{CP}$) for these hadrons are calculated. The centrality dependence of the average collective transverse velocity $<\beta (r)>$ for the hot and dense quark matter is obtained in Au+Au collisions, and it is applied to a relative smaller Cu+Cu collision system. The centrality dependence of $\mathrm{{p}_{T}}$ spectra and the $R_{CP}$ for $\pi^{0}$, $K_{s}^{0}$ and $\Lambda$ in Cu+Cu collisions at $\sqrt{s_{NN}}= 200$ GeV are well described. The results show that $<\beta (r)>$ is only a function of the number of participants $N_{part}$ and it is independent of the collision system.
[ { "created": "Tue, 19 Feb 2008 02:36:33 GMT", "version": "v1" }, { "created": "Thu, 5 Mar 2009 07:22:53 GMT", "version": "v2" } ]
2015-05-13
[ [ "Wang", "Yun-fei", "" ], [ "Shao", "Feng-lan", "" ], [ "Song", "Jun", "" ], [ "Wei", "De-ming", "" ], [ "Xie", "Qu-bing", "" ] ]
The centrality dependence of transverse momentum spectra for identified hadrons at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}= 200$ GeV is systematically studied in a quark combination model. The $\mathrm{{p}_{T}}$ spectra of $\pi^{\pm}$, $K^{\pm}$, $p(\bar{p})$ and $\Lambda(\bar{\Lambda})$ in different centrality bins and the nuclear modification factors ($R_{CP}$) for these hadrons are calculated. The centrality dependence of the average collective transverse velocity $<\beta (r)>$ for the hot and dense quark matter is obtained in Au+Au collisions, and it is applied to a relative smaller Cu+Cu collision system. The centrality dependence of $\mathrm{{p}_{T}}$ spectra and the $R_{CP}$ for $\pi^{0}$, $K_{s}^{0}$ and $\Lambda$ in Cu+Cu collisions at $\sqrt{s_{NN}}= 200$ GeV are well described. The results show that $<\beta (r)>$ is only a function of the number of participants $N_{part}$ and it is independent of the collision system.
1010.2116
Thorsten Feldmann
Thorsten Feldmann (Tech. Univ. Munich)
See-Saw Masses for Quarks and Leptons in SU(5)
15 pages, 4 figures (v3: outline restructured, modified mechanism to cancel anomalies)
JHEP 1104:043,2011
10.1007/JHEP04(2011)043
TUM-HEP-773/10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We build on a recent paper by Grinstein, Redi and Villadoro, where a see-saw like mechanism for quark masses was derived in the context of spontaneously broken gauged flavour symmetries. The see-saw mechanism is induced by heavy Dirac fermions which are added to the Standard Model spectrum in order to render the flavour symmetries anomaly-free. In this letter we report on the embedding of these fermions into multiplets of an SU(5) grand unified theory and discuss a number of interesting consequences.
[ { "created": "Mon, 11 Oct 2010 14:20:40 GMT", "version": "v1" }, { "created": "Thu, 4 Nov 2010 15:25:32 GMT", "version": "v2" }, { "created": "Fri, 25 Feb 2011 15:54:08 GMT", "version": "v3" } ]
2011-04-20
[ [ "Feldmann", "Thorsten", "", "Tech. Univ. Munich" ] ]
We build on a recent paper by Grinstein, Redi and Villadoro, where a see-saw like mechanism for quark masses was derived in the context of spontaneously broken gauged flavour symmetries. The see-saw mechanism is induced by heavy Dirac fermions which are added to the Standard Model spectrum in order to render the flavour symmetries anomaly-free. In this letter we report on the embedding of these fermions into multiplets of an SU(5) grand unified theory and discuss a number of interesting consequences.
1307.6845
Jorge S. Diaz
Jorge S. Diaz
Lorentz and CPT violation in the Neutrino Sector
Presented at the Sixth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 17-21, 2013
null
10.1142/9789814566438_0014
IUHET-580
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Searches for Lorentz and CPT violation using neutrino oscillations and the prospects for future tests using neutrino time-of-flight measurements and beta-decay experiments are presented.
[ { "created": "Thu, 25 Jul 2013 19:17:46 GMT", "version": "v1" } ]
2017-08-23
[ [ "Diaz", "Jorge S.", "" ] ]
Searches for Lorentz and CPT violation using neutrino oscillations and the prospects for future tests using neutrino time-of-flight measurements and beta-decay experiments are presented.
1711.04018
Zack Sullivan
Zack Sullivan
Are PDFs still consistent with Tevatron data?
7 p., to appear in "XLVIIth International Symposium on Multiparticle Dynamics (ISMD 2017)," EPJ Web of Conferences
null
10.1051/epjconf/201817203008
IIT-CAPP-17-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As active data taking has moved to the LHC at CERN, more and more LHC data have been included into fits of parton distribution functions. An anomaly has arisen where formerly excellent agreement between theoretical predictions and experiment in single-top-quark production at the Tevatron is no longer quite as good. Is this indicative of a deeper issue?
[ { "created": "Fri, 10 Nov 2017 21:23:16 GMT", "version": "v1" } ]
2018-03-14
[ [ "Sullivan", "Zack", "" ] ]
As active data taking has moved to the LHC at CERN, more and more LHC data have been included into fits of parton distribution functions. An anomaly has arisen where formerly excellent agreement between theoretical predictions and experiment in single-top-quark production at the Tevatron is no longer quite as good. Is this indicative of a deeper issue?
2008.09099
Sarunas Verner
John Ellis, Dimitri V. Nanopoulos, Keith A. Olive, Sarunas Verner
Non-Oscillatory No-Scale Inflation
16 pages, 7 figures, accepted for publication in JCAP
null
10.1088/1475-7516/2021/03/052
UMN-TH-3924/20, FTPI-MINN-20/27, KCL-PH-TH/2020-38, CERN-TH-2020-123, ACT-05-20, MI-TH-2020
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a non-oscillatory no-scale supergravity model of inflation (NO-NO inflation) in which the inflaton does not oscillate at the end of the inflationary era. Instead, the Universe is then dominated by the inflaton kinetic energy density (kination). During the transition from inflation to kination, the Universe preheats instantly through a coupling to Higgs-like fields. These rapidly annihilate and scatter into ultra-relativistic matter particles, which subsequently dominate the energy density, and reheating occurs at a temperature far above that of Big Bang Nucleosynthesis. After the electroweak transition, the inflaton enters a tracking phase as in some models of quintessential inflation. The model predictions for cosmic microwave background observables are consistent with Planck 2018 data, and the density of gravitational waves is below the upper bound from Big Bang Nucleosynthesis. We also find that the density of supersymmetric cold dark matter produced by gravitino decay is consistent with Planck 2018 data over the expected range of supersymmetric particle masses.
[ { "created": "Thu, 20 Aug 2020 17:40:35 GMT", "version": "v1" }, { "created": "Mon, 15 Mar 2021 17:37:59 GMT", "version": "v2" } ]
2021-03-31
[ [ "Ellis", "John", "" ], [ "Nanopoulos", "Dimitri V.", "" ], [ "Olive", "Keith A.", "" ], [ "Verner", "Sarunas", "" ] ]
We propose a non-oscillatory no-scale supergravity model of inflation (NO-NO inflation) in which the inflaton does not oscillate at the end of the inflationary era. Instead, the Universe is then dominated by the inflaton kinetic energy density (kination). During the transition from inflation to kination, the Universe preheats instantly through a coupling to Higgs-like fields. These rapidly annihilate and scatter into ultra-relativistic matter particles, which subsequently dominate the energy density, and reheating occurs at a temperature far above that of Big Bang Nucleosynthesis. After the electroweak transition, the inflaton enters a tracking phase as in some models of quintessential inflation. The model predictions for cosmic microwave background observables are consistent with Planck 2018 data, and the density of gravitational waves is below the upper bound from Big Bang Nucleosynthesis. We also find that the density of supersymmetric cold dark matter produced by gravitino decay is consistent with Planck 2018 data over the expected range of supersymmetric particle masses.
1801.00252
Raghunath Sahoo
Raghunath Sahoo
Comprehending Particle Production in Proton+Proton and Heavy-ion collisions at the Large Hadron Collider
Invited Plenary Talk in DAE-Nuclear Physics Symposium-2017, Thapar University, Patiala, India
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Particle production mechanisms in proton+proton and heavy-ion collisions at the LHC energies are discussed. An attempt is made to connect p+p to heavy-ion collisions in understanding the final state observables. New emerging phenomena like Multipartonic Interactions (MPI) and Color Reconnection (CR) mechanism are important in understanding heavy-ion like behaviors in high-multiplicity p+p events. Particle spectra, Multipartonic Interactions, Strangeness enhancement, Nuclear modification factor etc. are few of the aspects, which are discussed in this presentation.
[ { "created": "Sun, 31 Dec 2017 08:39:30 GMT", "version": "v1" } ]
2018-01-03
[ [ "Sahoo", "Raghunath", "" ] ]
Particle production mechanisms in proton+proton and heavy-ion collisions at the LHC energies are discussed. An attempt is made to connect p+p to heavy-ion collisions in understanding the final state observables. New emerging phenomena like Multipartonic Interactions (MPI) and Color Reconnection (CR) mechanism are important in understanding heavy-ion like behaviors in high-multiplicity p+p events. Particle spectra, Multipartonic Interactions, Strangeness enhancement, Nuclear modification factor etc. are few of the aspects, which are discussed in this presentation.
1604.08689
Johann Rafelski
Johann Rafelski and Jeremiah Birrell
The hot Hagedorn Universe
14 pages; EPJ Web of Conferences; presented at 4th International Conference on New Frontiers in Physics (ICNFP 2015) 23-30 Aug 2015,Kolymbari, Greece
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of the half-centenary of Hagedorn temperature and the statistical bootstrap model (SBM) we present a short account of how these insights coincided with the establishment of the hot big-bang model (BBM) and helped resolve some of the early philosophical difficulties. We then turn attention to the present day context and show the dominance of strong interaction quark and gluon degrees of freedom in the early stage, helping to characterize the properties of the hot Universe. We focus attention on the current experimental insights about cosmic microwave background (CMB) temperature fluctuation, and develop a much improved understanding of the neutrino freeze-out, in this way paving the path to the opening of a direct connection of quark-gluon plasma (QGP) physics in the early Universe with the QCD-lattice, and the study of the properties of QGP formed in the laboratory.
[ { "created": "Fri, 29 Apr 2016 05:07:13 GMT", "version": "v1" } ]
2016-05-02
[ [ "Rafelski", "Johann", "" ], [ "Birrell", "Jeremiah", "" ] ]
In the context of the half-centenary of Hagedorn temperature and the statistical bootstrap model (SBM) we present a short account of how these insights coincided with the establishment of the hot big-bang model (BBM) and helped resolve some of the early philosophical difficulties. We then turn attention to the present day context and show the dominance of strong interaction quark and gluon degrees of freedom in the early stage, helping to characterize the properties of the hot Universe. We focus attention on the current experimental insights about cosmic microwave background (CMB) temperature fluctuation, and develop a much improved understanding of the neutrino freeze-out, in this way paving the path to the opening of a direct connection of quark-gluon plasma (QGP) physics in the early Universe with the QCD-lattice, and the study of the properties of QGP formed in the laboratory.
1905.06952
Jonathan Kozaczuk
Nikita Blinov, Matthew J. Dolan, Patrick Draper, Jonathan Kozaczuk
Dark Matter Targets for Axion-like Particle Searches
20 pages, 5 figures
Phys. Rev. D 100, 015049 (2019)
10.1103/PhysRevD.100.015049
FERMILAB-PUB-19-197-A-T
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many existing and proposed experiments targeting QCD axion dark matter (DM) can also search for a broad class of axion-like particles (ALPs). We analyze the experimental sensitivities to electromagnetically-coupled ALP DM in different cosmological scenarios with the relic abundance set by the misalignment mechanism. We obtain benchmark DM targets for the standard thermal cosmology, a pre-nucleosynthesis period of early matter domination, and a period of kination. These targets are theoretically simple and assume $\mathcal{O}(1)$ misalignment angles, avoiding fine-tuning of the initial conditions. We find that some experiments will have sensitivity to these ALP DM targets before they are sensitive to the QCD axion, and others can potentially reach interesting targets below the QCD band. The ALP DM abundance also depends on the origin of the ALP mass. Temperature-dependent masses that are generated by strong dynamics (as for the QCD axion) correspond to DM candidates with smaller decay constants, resulting in even better detection prospects.
[ { "created": "Thu, 16 May 2019 18:00:00 GMT", "version": "v1" } ]
2019-08-07
[ [ "Blinov", "Nikita", "" ], [ "Dolan", "Matthew J.", "" ], [ "Draper", "Patrick", "" ], [ "Kozaczuk", "Jonathan", "" ] ]
Many existing and proposed experiments targeting QCD axion dark matter (DM) can also search for a broad class of axion-like particles (ALPs). We analyze the experimental sensitivities to electromagnetically-coupled ALP DM in different cosmological scenarios with the relic abundance set by the misalignment mechanism. We obtain benchmark DM targets for the standard thermal cosmology, a pre-nucleosynthesis period of early matter domination, and a period of kination. These targets are theoretically simple and assume $\mathcal{O}(1)$ misalignment angles, avoiding fine-tuning of the initial conditions. We find that some experiments will have sensitivity to these ALP DM targets before they are sensitive to the QCD axion, and others can potentially reach interesting targets below the QCD band. The ALP DM abundance also depends on the origin of the ALP mass. Temperature-dependent masses that are generated by strong dynamics (as for the QCD axion) correspond to DM candidates with smaller decay constants, resulting in even better detection prospects.
0808.3475
Damiano Anselmi
Damiano Anselmi
Weighted power counting, neutrino masses and Lorentz violating extensions of the Standard Model
26 pages; v2: more references and comments, PRD
Phys.Rev.D79:025017,2009
10.1103/PhysRevD.79.025017
IFUP-TH 2008/16
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Standard-Model extensions that have the following features: they violate Lorentz invariance explicitly at high energies; they are unitary, local, polynomial and renormalizable by weighted power counting; they contain the vertex (LH)^2, which gives Majorana masses to the neutrinos after symmetry breaking, and possibly four fermion interactions; they do not contain right-handed neutrinos, nor other extra fields. We study the simplest CPT invariant Standard-Model extension of this type in detail and prove the cancellation of gauge anomalies. We investigate the low-energy recovery of Lorentz invariance and comment on other types of extensions.
[ { "created": "Tue, 26 Aug 2008 10:12:57 GMT", "version": "v1" }, { "created": "Wed, 28 Jan 2009 07:54:45 GMT", "version": "v2" } ]
2009-02-26
[ [ "Anselmi", "Damiano", "" ] ]
We study the Standard-Model extensions that have the following features: they violate Lorentz invariance explicitly at high energies; they are unitary, local, polynomial and renormalizable by weighted power counting; they contain the vertex (LH)^2, which gives Majorana masses to the neutrinos after symmetry breaking, and possibly four fermion interactions; they do not contain right-handed neutrinos, nor other extra fields. We study the simplest CPT invariant Standard-Model extension of this type in detail and prove the cancellation of gauge anomalies. We investigate the low-energy recovery of Lorentz invariance and comment on other types of extensions.
0706.2578
Yuri Andreev
Yu. Andreev, N. Krasnikov and A. Toropin
Using the $e^\pm \mu^\mp + E^{miss}_T$ and $l^+l^- + E^{miss}_T$ Signatures in the Search for Supersymmetry and Constraining the MSSM model at LHC
26 pages, 13 figures
null
null
null
hep-ph
null
We study the $e^{\pm}\mu^{\mp} + E^{miss}_T$ and $l^+l^- + E^{miss}_T$ signatures $(l = e, \mu)$ for different values of $\tan\beta$ in the mSUGRA model. With $\tan\beta$ rising, we observe a characteristic change in the shape of dilepton mass spectra in $l^+l^- + E^{miss}_T $ versus $e^{\pm}\mu^{\mp}$ final states reflecting the decrease of $\tilde{\chi}^0_2 \to l^+l^- \tilde{\chi^0_1}$ branching ratio. We also study the non mSUGRA modifications of the CMS test point LM1 with arbitrary relations among gaugino and higgsino masses. For such modifications of the mSUGRA test point LM1 the number of lepton events depends rather strongly on the relations among gaugino and higgsino masses and in some modifications of the test point LM1 the signatures with leptons and $E_{T}^{miss}$ do not lead to the SUSY discovery and the single SUSY discovery signature remains the signature with $n \geq 2 jets + E^{miss}_T + no leptons$.
[ { "created": "Mon, 18 Jun 2007 11:07:21 GMT", "version": "v1" } ]
2007-06-19
[ [ "Andreev", "Yu.", "" ], [ "Krasnikov", "N.", "" ], [ "Toropin", "A.", "" ] ]
We study the $e^{\pm}\mu^{\mp} + E^{miss}_T$ and $l^+l^- + E^{miss}_T$ signatures $(l = e, \mu)$ for different values of $\tan\beta$ in the mSUGRA model. With $\tan\beta$ rising, we observe a characteristic change in the shape of dilepton mass spectra in $l^+l^- + E^{miss}_T $ versus $e^{\pm}\mu^{\mp}$ final states reflecting the decrease of $\tilde{\chi}^0_2 \to l^+l^- \tilde{\chi^0_1}$ branching ratio. We also study the non mSUGRA modifications of the CMS test point LM1 with arbitrary relations among gaugino and higgsino masses. For such modifications of the mSUGRA test point LM1 the number of lepton events depends rather strongly on the relations among gaugino and higgsino masses and in some modifications of the test point LM1 the signatures with leptons and $E_{T}^{miss}$ do not lead to the SUSY discovery and the single SUSY discovery signature remains the signature with $n \geq 2 jets + E^{miss}_T + no leptons$.
1712.09701
P. Q. Hung
P. Q. Hung
Mirror fermions and the strong CP problem: A new axionless solution and experimental implications
7 double-column pages, 0 figure. Note the change of title. The Higgs sector is changed and the treatment of the global symmetries of the model is much improved. The discussion of quark mass matrices has also been expanded. The basic conclusions are the same. arXiv admin note: substantial text overlap with arXiv:1704.06390
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new solution to the strong CP problem with distinct experimental signatures (long-lived particles) at the LHC is proposed. It is based on the Yukawa interactions between mirror quarks, Standard Model (SM) quarks and Higgs singlets. (Mirror quarks and leptons which include non-sterile right-handed neutrinos whose Majorana masses are proportional to the electroweak scale, form the basis of the EW-$\nu_R$ model.) The aforementioned Yukawa couplings can in general be complex and can contribute to $Arg\, Det M$ ($\bar{\theta} = \theta_{QCD} + Arg\, Det M$) at tree-level. The model contains a Peccei-Quinn-type global symmetry which allows it to rotate away $\theta_{QCD}$.The crux of matter in this manuscript is the fact that {\em no matter how large} the CP-violating phases in the Yukawa couplings might be, $Arg\, Det M$ can remain small i.e. $\bar{\theta} < 10^{-10}$ for reasonable values of the Yukawa couplings and, in fact, vanishes when the VEV of the Higgs singlet (responsible for the Dirac part of the neutrino mass in the seesaw mechanism) vanishes. The smallness of the contribution to $\bar{\theta}$ is {\em principally due} to the smallness of the ratio of the two mass scales in the seesaw mechanism: the Dirac and Majorana mass scales.
[ { "created": "Wed, 27 Dec 2017 22:58:03 GMT", "version": "v1" }, { "created": "Wed, 24 Oct 2018 18:35:21 GMT", "version": "v2" } ]
2018-10-29
[ [ "Hung", "P. Q.", "" ] ]
A new solution to the strong CP problem with distinct experimental signatures (long-lived particles) at the LHC is proposed. It is based on the Yukawa interactions between mirror quarks, Standard Model (SM) quarks and Higgs singlets. (Mirror quarks and leptons which include non-sterile right-handed neutrinos whose Majorana masses are proportional to the electroweak scale, form the basis of the EW-$\nu_R$ model.) The aforementioned Yukawa couplings can in general be complex and can contribute to $Arg\, Det M$ ($\bar{\theta} = \theta_{QCD} + Arg\, Det M$) at tree-level. The model contains a Peccei-Quinn-type global symmetry which allows it to rotate away $\theta_{QCD}$.The crux of matter in this manuscript is the fact that {\em no matter how large} the CP-violating phases in the Yukawa couplings might be, $Arg\, Det M$ can remain small i.e. $\bar{\theta} < 10^{-10}$ for reasonable values of the Yukawa couplings and, in fact, vanishes when the VEV of the Higgs singlet (responsible for the Dirac part of the neutrino mass in the seesaw mechanism) vanishes. The smallness of the contribution to $\bar{\theta}$ is {\em principally due} to the smallness of the ratio of the two mass scales in the seesaw mechanism: the Dirac and Majorana mass scales.
2309.09854
Yin-Fa Shen
Yin-Fa Shen, Jian-Peng Wang, Qin Qin
Possible large CP violation in charmed $\Lambda_b$ decays
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose that the cascade decay $\Lambda_b \to D(\to K^+\pi^-) N(\to p\pi^-)$ may serve as the discovery channel for baryonic CP violation. This decay chain is contributed by, dominantly, the amplitudes with the intermediate $D$ state as $D^0$ or $\bar{D}^0$. The large weak phase between the two kinds of amplitudes suggests the possibility of significant CP violation. While the presence of undetermined strong phases may complicate the dependence of CP asymmetry, our phenomenological analysis demonstrates that CP violation remains prominent across a broad range of strong phases. The mechanism also applies to similar decay modes such as $\Lambda_b \rightarrow D(\rightarrow K^+ K^-) \Lambda$. Considering the anticipated luminosity of LHCb, we conclude that these decay channels offer a promising opportunity to uncover CP violation in the baryon sector.
[ { "created": "Mon, 18 Sep 2023 15:15:08 GMT", "version": "v1" }, { "created": "Fri, 8 Dec 2023 04:15:00 GMT", "version": "v2" } ]
2023-12-11
[ [ "Shen", "Yin-Fa", "" ], [ "Wang", "Jian-Peng", "" ], [ "Qin", "Qin", "" ] ]
We propose that the cascade decay $\Lambda_b \to D(\to K^+\pi^-) N(\to p\pi^-)$ may serve as the discovery channel for baryonic CP violation. This decay chain is contributed by, dominantly, the amplitudes with the intermediate $D$ state as $D^0$ or $\bar{D}^0$. The large weak phase between the two kinds of amplitudes suggests the possibility of significant CP violation. While the presence of undetermined strong phases may complicate the dependence of CP asymmetry, our phenomenological analysis demonstrates that CP violation remains prominent across a broad range of strong phases. The mechanism also applies to similar decay modes such as $\Lambda_b \rightarrow D(\rightarrow K^+ K^-) \Lambda$. Considering the anticipated luminosity of LHCb, we conclude that these decay channels offer a promising opportunity to uncover CP violation in the baryon sector.
1412.4776
Chee Sheng Fong
Chee Sheng Fong, Davide Meloni, Aurora Meroni, Enrico Nardi
Leptogenesis in SO(10)
19 pages, 2 figures; references added and typos corrected to match the published version
JHEP 1501 (2015) 111
10.1007/JHEP01(2015)111
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider $SO(10)$ Grand Unified Theories (GUTs) with vacuum expectation values (vevs) for fermion masses in the $\mathbf{10} + \mathbf{\overline{126}}$ representation. We show that the baryon asymmetry generated via leptogenesis is completely determined in terms of measured low energy observables and of one single high energy parameter related to the ratio of the $\mathbf{10}$ and $\mathbf{\overline{126}}$ $SU(2)$ doublet vevs. We identify new decay channels for the heavy Majorana neutrinos into $SU(2)$ singlet leptons $e^c$ which can sizeably affect the size of the resulting baryon asymmetry. We describe how to equip $SO(10)$ fits to low energy data with the additional constraint of successful leptogenesis, and we apply this procedure to the fits carried out in ref.~\cite{Dueck:2013gca}. We show that a baryon asymmetry in perfect agreement with observations is obtained.
[ { "created": "Mon, 15 Dec 2014 21:00:02 GMT", "version": "v1" }, { "created": "Thu, 29 Jan 2015 19:44:37 GMT", "version": "v2" } ]
2015-01-30
[ [ "Fong", "Chee Sheng", "" ], [ "Meloni", "Davide", "" ], [ "Meroni", "Aurora", "" ], [ "Nardi", "Enrico", "" ] ]
We consider $SO(10)$ Grand Unified Theories (GUTs) with vacuum expectation values (vevs) for fermion masses in the $\mathbf{10} + \mathbf{\overline{126}}$ representation. We show that the baryon asymmetry generated via leptogenesis is completely determined in terms of measured low energy observables and of one single high energy parameter related to the ratio of the $\mathbf{10}$ and $\mathbf{\overline{126}}$ $SU(2)$ doublet vevs. We identify new decay channels for the heavy Majorana neutrinos into $SU(2)$ singlet leptons $e^c$ which can sizeably affect the size of the resulting baryon asymmetry. We describe how to equip $SO(10)$ fits to low energy data with the additional constraint of successful leptogenesis, and we apply this procedure to the fits carried out in ref.~\cite{Dueck:2013gca}. We show that a baryon asymmetry in perfect agreement with observations is obtained.
hep-ph/9703264
Paolo Gambino
Paolo Gambino (MPI Munich)
Two-loop heavy top effects on precision observables and the Higgs mass
11 pages, plain LaTeX. Talk given at the Workshop on "The Higgs puzzle - What can we learn from LEP II, LHC, NLC, and FMC?", Ringberg Castle, Germany, December 1996; to appear in the Proceedings, ed. B. Kniehl
null
null
MPI-PhT-97-016
hep-ph
null
The electroweak corrections induced by a heavy top on the main precision observables are now available up to O(g^4 mt^2/mw^2). The new results significantly reduce the theoretical uncertainty and have a sizable impact on the determination of sin^2theta_eff. We give precise predictions for mw and the effective sine in different renormalization schemes, estimate their accuracy, and discuss the implications for the indirect determination of M_H. From the present data for sin^2theta_eff we obtain M_H = 127 +143 -71 GeV (or M_H < 430 GeV at 95% C.L.).
[ { "created": "Fri, 7 Mar 1997 13:04:34 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gambino", "Paolo", "", "MPI Munich" ] ]
The electroweak corrections induced by a heavy top on the main precision observables are now available up to O(g^4 mt^2/mw^2). The new results significantly reduce the theoretical uncertainty and have a sizable impact on the determination of sin^2theta_eff. We give precise predictions for mw and the effective sine in different renormalization schemes, estimate their accuracy, and discuss the implications for the indirect determination of M_H. From the present data for sin^2theta_eff we obtain M_H = 127 +143 -71 GeV (or M_H < 430 GeV at 95% C.L.).
2305.10327
Damiano Francesco Giuseppe Fiorillo
Melissa Diamond, Damiano F.G. Fiorillo, Gustavo Marques-Tavares, Irene Tamborra, Edoardo Vitagliano
Multimessenger Constraints on Radiatively Decaying Axions from GW170817
Version accepted at Phys. Rev. Lett.; 5 pages, 3 figures + 5 pages, 3 figures
Phys.Rev.Lett. 132 (2024) 10, 101004
10.1103/PhysRevLett.132.101004
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The metastable hypermassive neutron star produced in the coalescence of two neutron stars can copiously produce axions that radiatively decay into $\mathcal{O}(100)$~MeV photons. These photons can form a fireball with characteristic temperature smaller than $1\rm\, MeV$. By relying on X-ray observations of GW170817/GRB 170817A with CALET CGBM, Konus-Wind, and Insight-HXMT/HE, we present new bounds on the axion-photon coupling for axion masses in the range $1$-$400\,\rm MeV$. We exclude couplings down to $5\times 10^{-11}\,\rm GeV^{-1}$, complementing and surpassing existing constraints. Our approach can be extended to any feebly-interacting particle decaying into photons.
[ { "created": "Wed, 17 May 2023 16:07:40 GMT", "version": "v1" }, { "created": "Fri, 8 Mar 2024 17:02:34 GMT", "version": "v2" } ]
2024-03-11
[ [ "Diamond", "Melissa", "" ], [ "Fiorillo", "Damiano F. G.", "" ], [ "Marques-Tavares", "Gustavo", "" ], [ "Tamborra", "Irene", "" ], [ "Vitagliano", "Edoardo", "" ] ]
The metastable hypermassive neutron star produced in the coalescence of two neutron stars can copiously produce axions that radiatively decay into $\mathcal{O}(100)$~MeV photons. These photons can form a fireball with characteristic temperature smaller than $1\rm\, MeV$. By relying on X-ray observations of GW170817/GRB 170817A with CALET CGBM, Konus-Wind, and Insight-HXMT/HE, we present new bounds on the axion-photon coupling for axion masses in the range $1$-$400\,\rm MeV$. We exclude couplings down to $5\times 10^{-11}\,\rm GeV^{-1}$, complementing and surpassing existing constraints. Our approach can be extended to any feebly-interacting particle decaying into photons.
1203.5174
Ian Lewis
Ian Lewis, Jared Schmitthenner
Uncovering the Charming Higgs at the LHC
11 pages, 8 figures. Discussion added to the conclusion, typos corrected, and references updated
JHEP 1206 (2012) 072
10.1007/JHEP06(2012)072
MADPH-12-1579
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the observability of the Higgs boson in the "charming Higgs" model. In this model the Higgs boson primarily undergoes a cascade decay to four charm quarks via light intermediate pseudoscalars. Such a decay allows the Higgs boson to escape the most stringent LEP bounds on the Standard Model Higgs boson mass. If the light pseudoscalars are sufficiently light they become highly boosted and their decay products collimated into jets. We show that by using jet substructure techniques, this model is potentially observable at the LHC. For a Higgs boson mass of 100 GeV and light pseudoscalar mass of 12 GeV, we find a signal significance of 3.8 sigma with a luminosity of 30 fb^-1 and that a 5 sigma significance can be obtained with 50 fb^-1 of luminosity at the 14 TeV LHC.
[ { "created": "Fri, 23 Mar 2012 04:23:28 GMT", "version": "v1" }, { "created": "Tue, 24 Jul 2012 14:19:07 GMT", "version": "v2" } ]
2012-07-25
[ [ "Lewis", "Ian", "" ], [ "Schmitthenner", "Jared", "" ] ]
We study the observability of the Higgs boson in the "charming Higgs" model. In this model the Higgs boson primarily undergoes a cascade decay to four charm quarks via light intermediate pseudoscalars. Such a decay allows the Higgs boson to escape the most stringent LEP bounds on the Standard Model Higgs boson mass. If the light pseudoscalars are sufficiently light they become highly boosted and their decay products collimated into jets. We show that by using jet substructure techniques, this model is potentially observable at the LHC. For a Higgs boson mass of 100 GeV and light pseudoscalar mass of 12 GeV, we find a signal significance of 3.8 sigma with a luminosity of 30 fb^-1 and that a 5 sigma significance can be obtained with 50 fb^-1 of luminosity at the 14 TeV LHC.
hep-ph/0612370
Kazuki Sakurai
S.-G. Kim, N. Maekawa, A. Matsuzaki, K. Sakurai and T. Yoshikawa
Lepton Flavor Violation in SUSY GUT Model with Non-universal Sfermion Masses
17 pages, 12 figures, v3 a reference added
Phys.Rev.D75:115008,2007
10.1103/PhysRevD.75.115008
DPNU-06-10
hep-ph
null
We analyze lepton flavor violating $\tau \to \mu \gamma$ and $\mu \to e \gamma$ processes in SUSY GUT model in which sfermions have special mass spectrum. It is assumed that only third generation sfermions which are contained in ${\bf 10}(Q, U^c, E^c)$ of SU(5) can have a different mass from the others. This mass spectrum is led from $E_6$ GUT model with horizontal symmetries. It is shown that branching ratios of $\tau \to \mu \gamma$ and $\mu \to e \gamma$ depend strongly on a right-handed stau mass. The weak scale stability requires the light stau, so large decay rates can be expected in this scenario. When stau is around 150 GeV and $\tan \beta \sim 10$, the branching ratios can be larger than $Br(\tau \to \mu \gamma) \simeq 10^{-8}$ and $Br(\mu \to e \gamma) \simeq 5\times 10^{-12}$, which are within reach of future experiments. In addition, this model has an interesting feature that the final state charged lepton tends to have the right-handed chirality.
[ { "created": "Fri, 29 Dec 2006 15:39:34 GMT", "version": "v1" }, { "created": "Sat, 30 Dec 2006 21:23:20 GMT", "version": "v2" }, { "created": "Tue, 9 Jan 2007 12:22:46 GMT", "version": "v3" } ]
2008-11-26
[ [ "Kim", "S. -G.", "" ], [ "Maekawa", "N.", "" ], [ "Matsuzaki", "A.", "" ], [ "Sakurai", "K.", "" ], [ "Yoshikawa", "T.", "" ] ]
We analyze lepton flavor violating $\tau \to \mu \gamma$ and $\mu \to e \gamma$ processes in SUSY GUT model in which sfermions have special mass spectrum. It is assumed that only third generation sfermions which are contained in ${\bf 10}(Q, U^c, E^c)$ of SU(5) can have a different mass from the others. This mass spectrum is led from $E_6$ GUT model with horizontal symmetries. It is shown that branching ratios of $\tau \to \mu \gamma$ and $\mu \to e \gamma$ depend strongly on a right-handed stau mass. The weak scale stability requires the light stau, so large decay rates can be expected in this scenario. When stau is around 150 GeV and $\tan \beta \sim 10$, the branching ratios can be larger than $Br(\tau \to \mu \gamma) \simeq 10^{-8}$ and $Br(\mu \to e \gamma) \simeq 5\times 10^{-12}$, which are within reach of future experiments. In addition, this model has an interesting feature that the final state charged lepton tends to have the right-handed chirality.
1206.5988
Aldo Deandrea
A. S. Cornell, Aldo Deandrea, Lu-Xin Liu, Ahmad Tarhini
The evolution of neutrino masses and mixings in the 5D MSSM
14 pages, 8 figures, 1 table
null
10.1103/PhysRevB.86.165305
LYCEN 2012-01; WITS-CTP-100
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a five-dimensional Minimal Supersymmetric Standard Model compactified on a S1/Z2 orbifold, and study the evolution of neutrino masses, mixing angles and phases for different values of tan beta and different radii of compactification. We consider the usual four dimensional Minimal Supersymmetric Standard Model limit plus two extra-dimensional scenarios: where all matter superfields can propagate in the bulk, and where they are constrained to the brane. We discuss in both cases the evolution of the mass spectrum, the implications for the mixing angles and the phases. We find that a large variation for the Dirac phase is possible, which makes models predicting maximal leptonic CP violation especially appealing.
[ { "created": "Tue, 26 Jun 2012 13:41:13 GMT", "version": "v1" } ]
2013-05-30
[ [ "Cornell", "A. S.", "" ], [ "Deandrea", "Aldo", "" ], [ "Liu", "Lu-Xin", "" ], [ "Tarhini", "Ahmad", "" ] ]
We consider a five-dimensional Minimal Supersymmetric Standard Model compactified on a S1/Z2 orbifold, and study the evolution of neutrino masses, mixing angles and phases for different values of tan beta and different radii of compactification. We consider the usual four dimensional Minimal Supersymmetric Standard Model limit plus two extra-dimensional scenarios: where all matter superfields can propagate in the bulk, and where they are constrained to the brane. We discuss in both cases the evolution of the mass spectrum, the implications for the mixing angles and the phases. We find that a large variation for the Dirac phase is possible, which makes models predicting maximal leptonic CP violation especially appealing.
hep-ph/0304104
Stuart Raby
Hyung Do Kim and Stuart Raby
Neutrinos in 5D SO(10) Unification
24 pages
JHEP 0307 (2003) 014
10.1088/1126-6708/2003/07/014
OHSTPY-HEP-T-03-003, KIAS-P03015
hep-ph
null
We study neutrino physics in a 5D supersymmetric SO(10) GUT. We analyze several different choices for realizing the See-Saw mechanism. We find that the "natural" scale for the Majorana mass of right-handed neutrinos depends critically on whether the right-handed neutrinos are located in the bulk or localized on a brane. In the former case, the effective Majorana mass is "naturally" of order the compactification scale, about 10^{14} GeV. Note, this is the value necessary for obtaining a light tau neutrino mass approximately 10^{-2} eV which, within the context of hierarchical neutrino masses, is the right order of magnitude to explain atmospheric neutrino oscillations. On the other-hand when the right-handed neutrino is localized on the brane, the effective Majorana mass is typically larger than the compactification scale. Nevertheless with small parameters of order 1/10 - 1/30, an effective Majorana mass of order 10^{14} GeV can be accommodated. We also discuss the constraints on model building resulting from the different scenarios for locating the right-handed neutrinos.
[ { "created": "Thu, 10 Apr 2003 16:13:29 GMT", "version": "v1" }, { "created": "Fri, 11 Apr 2003 17:01:15 GMT", "version": "v2" }, { "created": "Sun, 3 Aug 2003 16:01:10 GMT", "version": "v3" } ]
2009-11-10
[ [ "Kim", "Hyung Do", "" ], [ "Raby", "Stuart", "" ] ]
We study neutrino physics in a 5D supersymmetric SO(10) GUT. We analyze several different choices for realizing the See-Saw mechanism. We find that the "natural" scale for the Majorana mass of right-handed neutrinos depends critically on whether the right-handed neutrinos are located in the bulk or localized on a brane. In the former case, the effective Majorana mass is "naturally" of order the compactification scale, about 10^{14} GeV. Note, this is the value necessary for obtaining a light tau neutrino mass approximately 10^{-2} eV which, within the context of hierarchical neutrino masses, is the right order of magnitude to explain atmospheric neutrino oscillations. On the other-hand when the right-handed neutrino is localized on the brane, the effective Majorana mass is typically larger than the compactification scale. Nevertheless with small parameters of order 1/10 - 1/30, an effective Majorana mass of order 10^{14} GeV can be accommodated. We also discuss the constraints on model building resulting from the different scenarios for locating the right-handed neutrinos.
hep-ph/9606408
Gautam Bhattach
Gautam Bhattacharyya and Rabindra N. Mohapatra
A Non-supersymmetric Interpretation of the CDF e+e-\gamma\gamma + missing E_T Event
7 pages, Latex, no figures
Phys.Rev.D54:4204-4206,1996
10.1103/PhysRevD.54.R4204
IFUP-TH-32/96, UMD-PP-96-108
hep-ph
null
The $\eegg$ event reported recently by the CDF Collaboration has been interpreted as a signal of supersymmetry in several recent papers. In this article, we report on an alternative non-supersymmetric interpretation of the event using an extension of the standard model which contains new physics at the electroweak scale that does not effect the existing precision electroweak data. We extend the standard model by including an extra sequential generation of fermions, heavy right-handed neutrinos for all generations and an extra singly charged SU(2)-singlet Higgs boson. We discuss possible ways to discriminate this from the standard supersymemtric interpretations.
[ { "created": "Fri, 21 Jun 1996 18:26:20 GMT", "version": "v1" } ]
2009-12-30
[ [ "Bhattacharyya", "Gautam", "" ], [ "Mohapatra", "Rabindra N.", "" ] ]
The $\eegg$ event reported recently by the CDF Collaboration has been interpreted as a signal of supersymmetry in several recent papers. In this article, we report on an alternative non-supersymmetric interpretation of the event using an extension of the standard model which contains new physics at the electroweak scale that does not effect the existing precision electroweak data. We extend the standard model by including an extra sequential generation of fermions, heavy right-handed neutrinos for all generations and an extra singly charged SU(2)-singlet Higgs boson. We discuss possible ways to discriminate this from the standard supersymemtric interpretations.
hep-ph/9812340
Louis J. Clavelli
L. Clavelli (U. of Alabama)
Light Gluino Predictions for Jet Cross Sections in Tevatron Run II
10 pages including 4 PS figures, revtex.sty, Run II Conference report
null
null
UAHEP9812
hep-ph
null
The CDF inclusive jet transverse energy cross section at 1.8 TeV suggests anomalous behavior at both low and high transverse energies. In addition the scaled ratio of the 0.63 TeV to 1.8 TeV data lies significantly below the standard model prediction and suggests structure not attributable to standard model processes. These anomalies are in line with what would be expected in the light gluino scenario. We perform a unified fit and extrapolate to two TeV to predict the results at run II.
[ { "created": "Fri, 11 Dec 1998 23:02:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Clavelli", "L.", "", "U. of Alabama" ] ]
The CDF inclusive jet transverse energy cross section at 1.8 TeV suggests anomalous behavior at both low and high transverse energies. In addition the scaled ratio of the 0.63 TeV to 1.8 TeV data lies significantly below the standard model prediction and suggests structure not attributable to standard model processes. These anomalies are in line with what would be expected in the light gluino scenario. We perform a unified fit and extrapolate to two TeV to predict the results at run II.
1901.04151
Guo-Liang Ma
Xin-Li Zhao, Guo-Liang Ma, Yu-Gang Ma
Impact of magnetic-field fluctuations on measurements of the chiral magnetic effect in collisions of isobaric nuclei
12 pages, 20 figures; final published version (selected as Editors' Suggestion)
Phys. Rev. C 99, 034903 (2019)
10.1103/PhysRevC.99.034903
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the properties of electromagnetic fields in isobaric $_{44}^{96}\textrm{Ru}+\,_{44}^{96}\textrm{Ru}$ and $_{40}^{96}\textrm{Zr}+\,_{40}^{96}\textrm{Zr}$ collisions at $\sqrt{s}$ = 200 GeV by using a multiphase transport model, with special emphasis on the correlation between magnetic field direction and participant plane angle $\Psi_{2}$ (or spectator plane angle $\Psi_{2}^{\rm SP}$), i.e. $\langle{\rm cos}\ 2(\Psi_B - \Psi_{2})\rangle$ [or $\langle{\rm cos}\ 2(\Psi_B - \Psi_{2}^{\rm SP})\rangle$]. We confirm that the magnetic fields of $_{44}^{96}\textrm{Ru}+\,_{44}^{96}\textrm{Ru}$ collisions are stronger than those of $_{40}^{96}\textrm{Zr}+\,_{40}^{96}\textrm{Zr}$ collisions due to their larger proton fraction. We find that the deformation of nuclei has a non-negligible effect on $\langle{\rm cos}\ 2(\Psi_B - \Psi_{2})\rangle$ especially in peripheral events. Because the magnetic-field direction is more strongly correlated with $\Psi_{2}^{\rm SP}$ than with $\Psi_{2}$, the relative difference of the chiral magnetic effect observable with respect to $\Psi_{2}^{\rm SP}$ is expected to be able to reflect much cleaner information about the chiral magnetic effect with less influences of deformation.
[ { "created": "Mon, 14 Jan 2019 06:50:08 GMT", "version": "v1" }, { "created": "Wed, 27 Mar 2019 02:14:08 GMT", "version": "v2" } ]
2019-03-28
[ [ "Zhao", "Xin-Li", "" ], [ "Ma", "Guo-Liang", "" ], [ "Ma", "Yu-Gang", "" ] ]
We investigate the properties of electromagnetic fields in isobaric $_{44}^{96}\textrm{Ru}+\,_{44}^{96}\textrm{Ru}$ and $_{40}^{96}\textrm{Zr}+\,_{40}^{96}\textrm{Zr}$ collisions at $\sqrt{s}$ = 200 GeV by using a multiphase transport model, with special emphasis on the correlation between magnetic field direction and participant plane angle $\Psi_{2}$ (or spectator plane angle $\Psi_{2}^{\rm SP}$), i.e. $\langle{\rm cos}\ 2(\Psi_B - \Psi_{2})\rangle$ [or $\langle{\rm cos}\ 2(\Psi_B - \Psi_{2}^{\rm SP})\rangle$]. We confirm that the magnetic fields of $_{44}^{96}\textrm{Ru}+\,_{44}^{96}\textrm{Ru}$ collisions are stronger than those of $_{40}^{96}\textrm{Zr}+\,_{40}^{96}\textrm{Zr}$ collisions due to their larger proton fraction. We find that the deformation of nuclei has a non-negligible effect on $\langle{\rm cos}\ 2(\Psi_B - \Psi_{2})\rangle$ especially in peripheral events. Because the magnetic-field direction is more strongly correlated with $\Psi_{2}^{\rm SP}$ than with $\Psi_{2}$, the relative difference of the chiral magnetic effect observable with respect to $\Psi_{2}^{\rm SP}$ is expected to be able to reflect much cleaner information about the chiral magnetic effect with less influences of deformation.
1908.10861
Robert McGehee
Jeff A. Dror, Gilly Elor, and Robert McGehee
Absorption of Fermionic Dark Matter by Nuclear Targets
30 pages plus appendices, 8 figures, 3 tables. v2: published in JHEP with minor revisions (no change to results)
JHEP 02 (2020) 134
10.1007/JHEP02(2020)134
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Absorption of fermionic dark matter leads to a range of distinct and novel signatures at dark matter direct detection and neutrino experiments. We study the possible signals from fermionic absorption by nuclear targets, which we divide into two classes of four Fermi operators: neutral and charged current. In the neutral current signal, dark matter is absorbed by a target nucleus and a neutrino is emitted. This results in a characteristically different nuclear recoil energy spectrum from that of elastic scattering. The charged current channel leads to induced $\beta$ decays in isotopes which are stable in vacuum as well as shifts of the kinematic endpoint of $ \beta$ spectra in unstable isotopes. To confirm the possibility of observing these signals in light of other constraints, we introduce UV completions of example higher dimensional operators that lead to fermionic absorption signals and study their phenomenology. Most prominently, dark matter which exhibits fermionic absorption signals is necessarily unstable leading to stringent bounds from indirect detection searches. Nevertheless, we find a large viable parameter space in which dark matter is sufficiently long lived and detectable in current and future experiments.
[ { "created": "Wed, 28 Aug 2019 17:59:59 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 2020 09:12:28 GMT", "version": "v2" } ]
2022-09-13
[ [ "Dror", "Jeff A.", "" ], [ "Elor", "Gilly", "" ], [ "McGehee", "Robert", "" ] ]
Absorption of fermionic dark matter leads to a range of distinct and novel signatures at dark matter direct detection and neutrino experiments. We study the possible signals from fermionic absorption by nuclear targets, which we divide into two classes of four Fermi operators: neutral and charged current. In the neutral current signal, dark matter is absorbed by a target nucleus and a neutrino is emitted. This results in a characteristically different nuclear recoil energy spectrum from that of elastic scattering. The charged current channel leads to induced $\beta$ decays in isotopes which are stable in vacuum as well as shifts of the kinematic endpoint of $ \beta$ spectra in unstable isotopes. To confirm the possibility of observing these signals in light of other constraints, we introduce UV completions of example higher dimensional operators that lead to fermionic absorption signals and study their phenomenology. Most prominently, dark matter which exhibits fermionic absorption signals is necessarily unstable leading to stringent bounds from indirect detection searches. Nevertheless, we find a large viable parameter space in which dark matter is sufficiently long lived and detectable in current and future experiments.
1005.1689
Seung-il Nam
Seung-il Nam, Chung-Wen Kao
Chiral restoration at finite temperature with meson loop corrections
12 pages, 6 figures
Phys.Rev.D82:096001,2010
10.1103/PhysRevD.82.096001
CYCU-HEP-10-05
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate chiral-restoration patterns of QCD for N_{c}=3 and N_{f}=2 at finite temperature (T) and zero quark-chemical potential beyond the chiral limit, indicating the explicit chiral-symmetry breaking. To this end, we employ the instanton-vacuum configuration for the flavor SU(2) sector and the Harrington-Shepard caloron for modifying relevant instanton parameters as functions of T. The meson-loop corrections (MLC), which correspond to 1/N_{c} corrections, are also taken into account to reproduce appropriate m_{q} dependences of chiral order parameters. We compute chiral condensate as a function of T and/or m_{q}. From the numerical calculations, we observe that MLC play an important role to have a correct universality-class behavior of chiral-restoration patterns in this framework, depending on m_{q}: Second-order phase transition in the chiral limit, m_{q}=0 and crossover for m_{q}>0. Without MLC, all the restoration patterns are crossover, due to simple saddle-point approximations. It turns out that T^{\chi}_{c}=159 MeV in the chiral limit and T^{\chi}_{c}=(177,186,196) MeV for m_{q}=(5,10,15) MeV, using the phenomenological choices for the instanton parameters at T=0.
[ { "created": "Mon, 10 May 2010 23:38:17 GMT", "version": "v1" }, { "created": "Fri, 8 Oct 2010 02:37:04 GMT", "version": "v2" } ]
2010-11-11
[ [ "Nam", "Seung-il", "" ], [ "Kao", "Chung-Wen", "" ] ]
We investigate chiral-restoration patterns of QCD for N_{c}=3 and N_{f}=2 at finite temperature (T) and zero quark-chemical potential beyond the chiral limit, indicating the explicit chiral-symmetry breaking. To this end, we employ the instanton-vacuum configuration for the flavor SU(2) sector and the Harrington-Shepard caloron for modifying relevant instanton parameters as functions of T. The meson-loop corrections (MLC), which correspond to 1/N_{c} corrections, are also taken into account to reproduce appropriate m_{q} dependences of chiral order parameters. We compute chiral condensate as a function of T and/or m_{q}. From the numerical calculations, we observe that MLC play an important role to have a correct universality-class behavior of chiral-restoration patterns in this framework, depending on m_{q}: Second-order phase transition in the chiral limit, m_{q}=0 and crossover for m_{q}>0. Without MLC, all the restoration patterns are crossover, due to simple saddle-point approximations. It turns out that T^{\chi}_{c}=159 MeV in the chiral limit and T^{\chi}_{c}=(177,186,196) MeV for m_{q}=(5,10,15) MeV, using the phenomenological choices for the instanton parameters at T=0.
2006.01042
BingRan He
Qi Zhang, Bing-Ran He, Jia-Lun Ping
Pentaquarks with the $qqs\bar{Q}Q$ configuration in the Chiral Quark Model
10 pages, 1 figure
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the five-quark system composed of $qqs\bar{Q}Q$ configuration ($q = u$ or $d$, $Q=b$ or $c$), in the framework of the chiral quark model. In consequence, a series of bound states with heavy flavors are predicted by precise five-body dynamical calculations. We found that taking color-octet structure into consideration always provides more bounding energy than color-singlet structure, and the more heavier quark prevents, the easier to form the bound states. We suggest $qqs\bar{b}b$ configuration is a compact $\bar{b}b$-pair surrounded by three other quarks, while $qqs\bar{b}c$, $qqs\bar{c}b$ and $qqs\bar{c}c$ configurations are molecular states.
[ { "created": "Mon, 1 Jun 2020 16:16:57 GMT", "version": "v1" } ]
2020-06-02
[ [ "Zhang", "Qi", "" ], [ "He", "Bing-Ran", "" ], [ "Ping", "Jia-Lun", "" ] ]
We study the five-quark system composed of $qqs\bar{Q}Q$ configuration ($q = u$ or $d$, $Q=b$ or $c$), in the framework of the chiral quark model. In consequence, a series of bound states with heavy flavors are predicted by precise five-body dynamical calculations. We found that taking color-octet structure into consideration always provides more bounding energy than color-singlet structure, and the more heavier quark prevents, the easier to form the bound states. We suggest $qqs\bar{b}b$ configuration is a compact $\bar{b}b$-pair surrounded by three other quarks, while $qqs\bar{b}c$, $qqs\bar{c}b$ and $qqs\bar{c}c$ configurations are molecular states.
0904.0759
Yasutaka Takanishi
S. T. Petcov, H. Sugiyama, Y. Takanishi
Neutrinoless Double Beta Decay and H^{\pm\pm}\to {l'}^\pm l^\pm Decays in the Higgs Triplet Model
21 pages, 10 figs
Phys.Rev.D80:015005,2009
10.1103/PhysRevD.80.015005
SISSA 18/2009/EP, TUM-HEP-717/09, IPMU09-0037
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The connection between the neutrinoless double beta ((\beta\beta)_{0 \nu}-) decay effective Majorana mass, |M_{ee}|, and the branching ratios of the decays H^{\pm\pm}\to l^\pm {l'}^\pm, l,{l'}= e,\mu, of the doubly charged Higgs boson H^{\pm\pm} is analysed within the Higgs Triplet Model of neutrino mass generation. We work in the version of the model with explicit breaking of the total lepton charge conservation, in which H^{\pm\pm}\to l^\pm {l'}^\pm, l,{l'} = e,\mu,\tau, are the dominant decay modes of H^{\pm\pm}. It is assumed also that H^{\pm\pm} are relatively light so that they can be produced at LHC and the branching ratios of interest measured. Taking into account the current and prospective uncertainties in the values of the neutrino mixing parameters most relevant for the problem studied - the atmospheric neutrino mixing angle \theta_{23} and the CHOOZ angle \theta_{13}, and allowing the lightest neutrino mass and the CP violating Dirac and Majorana phases to vary in the intervals [0, 0.3 eV] and [0, 2\pi], respectively, we derive the regions of values of BR(H^{\pm\pm}\to e^\pm e^\pm) and BR(H^{\pm\pm}\to e^\pm \mu^\pm) for which |M_{ee}|\geq 0.05 eV, or |M_{ee}| < 0.05 eV. This is done for neutrino mass spectrum with normal ordering, inverted ordering and in the case when the type of the spectrum is not known, and i) without using the possible additional data on BR(H^{\pm\pm}\to \mu^\pm \mu^\pm), ii) using prospective data on BR(H^{\pm\pm}\to \mu^\pm \mu^\pm). In the latter case results for several values of BR(H^{\pm\pm}\to \mu^\pm\mu^\pm) are presented.
[ { "created": "Sun, 5 Apr 2009 10:05:21 GMT", "version": "v1" } ]
2009-09-02
[ [ "Petcov", "S. T.", "" ], [ "Sugiyama", "H.", "" ], [ "Takanishi", "Y.", "" ] ]
The connection between the neutrinoless double beta ((\beta\beta)_{0 \nu}-) decay effective Majorana mass, |M_{ee}|, and the branching ratios of the decays H^{\pm\pm}\to l^\pm {l'}^\pm, l,{l'}= e,\mu, of the doubly charged Higgs boson H^{\pm\pm} is analysed within the Higgs Triplet Model of neutrino mass generation. We work in the version of the model with explicit breaking of the total lepton charge conservation, in which H^{\pm\pm}\to l^\pm {l'}^\pm, l,{l'} = e,\mu,\tau, are the dominant decay modes of H^{\pm\pm}. It is assumed also that H^{\pm\pm} are relatively light so that they can be produced at LHC and the branching ratios of interest measured. Taking into account the current and prospective uncertainties in the values of the neutrino mixing parameters most relevant for the problem studied - the atmospheric neutrino mixing angle \theta_{23} and the CHOOZ angle \theta_{13}, and allowing the lightest neutrino mass and the CP violating Dirac and Majorana phases to vary in the intervals [0, 0.3 eV] and [0, 2\pi], respectively, we derive the regions of values of BR(H^{\pm\pm}\to e^\pm e^\pm) and BR(H^{\pm\pm}\to e^\pm \mu^\pm) for which |M_{ee}|\geq 0.05 eV, or |M_{ee}| < 0.05 eV. This is done for neutrino mass spectrum with normal ordering, inverted ordering and in the case when the type of the spectrum is not known, and i) without using the possible additional data on BR(H^{\pm\pm}\to \mu^\pm \mu^\pm), ii) using prospective data on BR(H^{\pm\pm}\to \mu^\pm \mu^\pm). In the latter case results for several values of BR(H^{\pm\pm}\to \mu^\pm\mu^\pm) are presented.
1111.6096
Aurore Courtoy
A. Courtoy
The role of the running coupling constant in the unveiling of the hadronic structure
To appear in the proceedings of the International Workshop on QCD Green's Functions, Confinement and Phenomenology, September 05-09, 2011,Trento, Italy ; PoS style
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the main open questions in physics is the understanding of the internal structure of the strongly interacting particles, or hadrons. It is still a challenge to describe consistently the dynamics of scattering processes and hadronic structure at moderate energy scales. The study of Parton Distribution Functions (PDFs) sets a connection between the perturbative and non-perturbative worlds, through the following scheme: one builds models consistent with QCD in a moderate energy range, PDFs are evaluated in these models, and, finally, the scale dependence of these distributions is studied. In these proceedings, we revisit the standard procedure to match non-perturbative models to perturbative QCD, using experimental data. The strong coupling constant plays a central role in the QCD evolution of parton densities. We will extend this procedure with a non-perturbative generalization of the QCD running coupling and use this new development to understand why perturbative treatments are working reasonably well in the context of hadronic models. Vice versa, this new procedure broadens the ways of analyzing the freezing of the running coupling constant.
[ { "created": "Fri, 25 Nov 2011 20:13:31 GMT", "version": "v1" } ]
2011-11-28
[ [ "Courtoy", "A.", "" ] ]
One of the main open questions in physics is the understanding of the internal structure of the strongly interacting particles, or hadrons. It is still a challenge to describe consistently the dynamics of scattering processes and hadronic structure at moderate energy scales. The study of Parton Distribution Functions (PDFs) sets a connection between the perturbative and non-perturbative worlds, through the following scheme: one builds models consistent with QCD in a moderate energy range, PDFs are evaluated in these models, and, finally, the scale dependence of these distributions is studied. In these proceedings, we revisit the standard procedure to match non-perturbative models to perturbative QCD, using experimental data. The strong coupling constant plays a central role in the QCD evolution of parton densities. We will extend this procedure with a non-perturbative generalization of the QCD running coupling and use this new development to understand why perturbative treatments are working reasonably well in the context of hadronic models. Vice versa, this new procedure broadens the ways of analyzing the freezing of the running coupling constant.
hep-ph/0604120
Fawzi Boudjema
C.Buttar, S.Dittmaier, V.Drollinger, S.Frixione, A.Nikitenko, S.Willenbrock S.Abdullin, E.Accomando, D.Acosta, A.Arbuzov, R.D.Ball, A.Ballestrero, P.Bartalini, U.Baur, A.Belhouari, S.Belov, A.Belyaev, D.Benedetti, T.Binoth, S.Bolognesi, S.Bondarenko, E.E.Boos, F.Boudjema, A.Bredenstein, V.E.Bunichev, C.Buttar, J.M.Campbell, C.Carloni Calame, S.Catani, R.Cavanaugh, M.Ciccolini, J.Collins, A.M.Cooper-Sarkar, G.Corcella, S.Cucciarelli, G.Davatz, V.DelDuca, A.Denner, J.D'Hondt, S.Dittmaier, V.Drollinger, A.Drozdetskiy, L.V.Dudko, M.Duehrssen, R.Frazier, S.Frixione, J.Fujimoto, S.Gascon-Shotkin, T.Gehrmann, A.Gehrmann-De Ridder, A.Giammanco, A.-S.Giolo-Nicollerat, E.W.N.Glover, R.M.Godbole, A.Grau, M.Grazzini, J.-Ph.Guillet, A.Gusev, R.Harlander, R.Hegde, G.Heinrich, J.Heyninck, J.Huston, T.Ishikawa, A.Kalinowski, T.Kaneko, K.Kato, N.Kauer, W.Kilgore, M.Kirsanov, A.Korytov, M.Kraemer, A.Kulesza, Y.Kurihara, S.Lehti, L.Magnea, F.Mahmoudi, E.Maina, F.Maltoni, C.Mariotti, B.Mellado, D.Mercier, G.Mitselmakher, G.Montagna, A.Moraes, M.Moretti, S.Moretti, I.Nakano, P.Nason, O.Nicrosini, A.Nikitenko, M.R.Nolten, F.Olness, Yu.Pakhotin, G.Pancheri, F.Piccinini, E.Pilon, R.Pittau, S.Pozzorini, J.Pumplin, W.Quayle, D.A.Ross, R.Sadykov, M.Sandhoff, V.I.Savrin, A.Schmidt, M.Schulze, S.Schumann, B.Scurlock, A.Sherstnev, P.Skands, G.Somogyi, J.Smith, M.Spira, Y.Srivastava, H.Stenzel, Y.Sumino, R.Tanaka, Z.Trocsanyi, S.Tsuno, A.Vicini, D.Wackeroth, M.M.Weber, C.Weiser, S.Willenbrock, S.L.Wu, M.Zanetti
Les Houches Physics at TeV Colliders 2005, Standard Model and Higgs working group: Summary report
234 pages, 173 figures. Web page of the workshop (with links to the talks): http://lappweb.in2p3.fr/conferences/LesHouches/Houches2005/
null
null
null
hep-ph
null
This Report summarises the activities of the "SM and Higgs" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005. On the one hand, we performed a variety of experimental and theoretical studies on standard candles (such as W, Z, and ttbar production), treating them either as proper signals of known physics, or as backgrounds to unknown physics; we also addressed issues relevant to those non-perturbative or semi-perturbative ingredients, such as Parton Density Functions and Underlying Events, whose understanding will be crucial for a proper simulation of the actual events taking place in the detectors. On the other hand, several channels for the production of the Higgs, or involving the Higgs, have been considered in some detail. The report is structured into four main parts. The first one deals with Standard Model physics, except the Higgs. A variety of arguments are treated here, from full simulation of processes constituting a background to Higgs production, to studies of uncertainties due to PDFs and to extrapolations of models for underlying events, from small-$x$ issues to electroweak corrections which may play a role in vector boson physics. The second part of the report treats Higgs physics from the point of view of the signal. In the third part, reviews are presented on the current status of multi-leg, next-to-leading order and of next-to-next-to-leading order QCD computations. Finally, the fourth part deals with the use of Monte Carlos for simulation of LHC physics.
[ { "created": "Thu, 13 Apr 2006 14:53:53 GMT", "version": "v1" } ]
2009-09-29
[ [ "Buttar", "C.", "" ], [ "Dittmaier", "S.", "" ], [ "Drollinger", "V.", "" ], [ "Frixione", "S.", "" ], [ "Nikitenko", "A.", "" ], [ "Abdullin", "S. Willenbrock S.", "" ], [ "Accomando", "E.", "" ], [ "Acosta", "D.", "" ], [ "Arbuzov", "A.", "" ], [ "Ball", "R. D.", "" ], [ "Ballestrero", "A.", "" ], [ "Bartalini", "P.", "" ], [ "Baur", "U.", "" ], [ "Belhouari", "A.", "" ], [ "Belov", "S.", "" ], [ "Belyaev", "A.", "" ], [ "Benedetti", "D.", "" ], [ "Binoth", "T.", "" ], [ "Bolognesi", "S.", "" ], [ "Bondarenko", "S.", "" ], [ "Boos", "E. E.", "" ], [ "Boudjema", "F.", "" ], [ "Bredenstein", "A.", "" ], [ "Bunichev", "V. E.", "" ], [ "Buttar", "C.", "" ], [ "Campbell", "J. M.", "" ], [ "Calame", "C. Carloni", "" ], [ "Catani", "S.", "" ], [ "Cavanaugh", "R.", "" ], [ "Ciccolini", "M.", "" ], [ "Collins", "J.", "" ], [ "Cooper-Sarkar", "A. M.", "" ], [ "Corcella", "G.", "" ], [ "Cucciarelli", "S.", "" ], [ "Davatz", "G.", "" ], [ "DelDuca", "V.", "" ], [ "Denner", "A.", "" ], [ "D'Hondt", "J.", "" ], [ "Dittmaier", "S.", "" ], [ "Drollinger", "V.", "" ], [ "Drozdetskiy", "A.", "" ], [ "Dudko", "L. V.", "" ], [ "Duehrssen", "M.", "" ], [ "Frazier", "R.", "" ], [ "Frixione", "S.", "" ], [ "Fujimoto", "J.", "" ], [ "Gascon-Shotkin", "S.", "" ], [ "Gehrmann", "T.", "" ], [ "Ridder", "A. Gehrmann-De", "" ], [ "Giammanco", "A.", "" ], [ "Giolo-Nicollerat", "A. -S.", "" ], [ "Glover", "E. W. N.", "" ], [ "Godbole", "R. M.", "" ], [ "Grau", "A.", "" ], [ "Grazzini", "M.", "" ], [ "Guillet", "J. -Ph.", "" ], [ "Gusev", "A.", "" ], [ "Harlander", "R.", "" ], [ "Hegde", "R.", "" ], [ "Heinrich", "G.", "" ], [ "Heyninck", "J.", "" ], [ "Huston", "J.", "" ], [ "Ishikawa", "T.", "" ], [ "Kalinowski", "A.", "" ], [ "Kaneko", "T.", "" ], [ "Kato", "K.", "" ], [ "Kauer", "N.", "" ], [ "Kilgore", "W.", "" ], [ "Kirsanov", "M.", "" ], [ "Korytov", "A.", "" ], [ "Kraemer", "M.", "" ], [ "Kulesza", "A.", "" ], [ "Kurihara", "Y.", "" ], [ "Lehti", "S.", "" ], [ "Magnea", "L.", "" ], [ "Mahmoudi", "F.", "" ], [ "Maina", "E.", "" ], [ "Maltoni", "F.", "" ], [ "Mariotti", "C.", "" ], [ "Mellado", "B.", "" ], [ "Mercier", "D.", "" ], [ "Mitselmakher", "G.", "" ], [ "Montagna", "G.", "" ], [ "Moraes", "A.", "" ], [ "Moretti", "M.", "" ], [ "Moretti", "S.", "" ], [ "Nakano", "I.", "" ], [ "Nason", "P.", "" ], [ "Nicrosini", "O.", "" ], [ "Nikitenko", "A.", "" ], [ "Nolten", "M. R.", "" ], [ "Olness", "F.", "" ], [ "Pakhotin", "Yu.", "" ], [ "Pancheri", "G.", "" ], [ "Piccinini", "F.", "" ], [ "Pilon", "E.", "" ], [ "Pittau", "R.", "" ], [ "Pozzorini", "S.", "" ], [ "Pumplin", "J.", "" ], [ "Quayle", "W.", "" ], [ "Ross", "D. A.", "" ], [ "Sadykov", "R.", "" ], [ "Sandhoff", "M.", "" ], [ "Savrin", "V. I.", "" ], [ "Schmidt", "A.", "" ], [ "Schulze", "M.", "" ], [ "Schumann", "S.", "" ], [ "Scurlock", "B.", "" ], [ "Sherstnev", "A.", "" ], [ "Skands", "P.", "" ], [ "Somogyi", "G.", "" ], [ "Smith", "J.", "" ], [ "Spira", "M.", "" ], [ "Srivastava", "Y.", "" ], [ "Stenzel", "H.", "" ], [ "Sumino", "Y.", "" ], [ "Tanaka", "R.", "" ], [ "Trocsanyi", "Z.", "" ], [ "Tsuno", "S.", "" ], [ "Vicini", "A.", "" ], [ "Wackeroth", "D.", "" ], [ "Weber", "M. M.", "" ], [ "Weiser", "C.", "" ], [ "Willenbrock", "S.", "" ], [ "Wu", "S. L.", "" ], [ "Zanetti", "M.", "" ] ]
This Report summarises the activities of the "SM and Higgs" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005. On the one hand, we performed a variety of experimental and theoretical studies on standard candles (such as W, Z, and ttbar production), treating them either as proper signals of known physics, or as backgrounds to unknown physics; we also addressed issues relevant to those non-perturbative or semi-perturbative ingredients, such as Parton Density Functions and Underlying Events, whose understanding will be crucial for a proper simulation of the actual events taking place in the detectors. On the other hand, several channels for the production of the Higgs, or involving the Higgs, have been considered in some detail. The report is structured into four main parts. The first one deals with Standard Model physics, except the Higgs. A variety of arguments are treated here, from full simulation of processes constituting a background to Higgs production, to studies of uncertainties due to PDFs and to extrapolations of models for underlying events, from small-$x$ issues to electroweak corrections which may play a role in vector boson physics. The second part of the report treats Higgs physics from the point of view of the signal. In the third part, reviews are presented on the current status of multi-leg, next-to-leading order and of next-to-next-to-leading order QCD computations. Finally, the fourth part deals with the use of Monte Carlos for simulation of LHC physics.
hep-ph/0002227
Zhou Yu-feng
Yue-Liang Wu and Yu-Feng Zhou
Weak Phase $\gamma$ and Strong Phase $\delta$ from CP Averaged $B\to \pi\pi$ and $\pi K$ Decays
14 Pages, ReVTeX, 5 figures, one figure (Fig.3) is corrected
Phys.Rev.D62:036007,2000
10.1103/PhysRevD.62.036007
null
hep-ph
null
Assuming SU(3) symmetry for the strong phases in the four decay modes $B\rarrow \pi^-\pi^+, \pi^0 \pi^+, \pi^- K^+, \pi^- \bar{K}^0$ and ignoring the relative small electroweak penguin effects in those decays, the weak phase $\gamma$ and the strong phase $\delta$ can be determined in a model independent way by the CP-averaged branching ratios of the four decay modes. It appears that the current experimental data for $B\to \pi\pi$ and $\pi K$ decays prefer a negative value of $\cos\gamma\cos\delta$. By combining with the other constraints from $V_{ub}$, $B^{0}_{d,s}-\bar{B}^{0}_{d,s}$ mixings and indirect CP-violating parameter $\epsilon_K$ within the standard model, two favorable solutions for the phases $\gamma$ and $\delta$ are found to lie in the region: $35^{\circ}\alt\gamma\alt 62^{\circ}$ and $106^{\circ}\alt \delta \alt 180^{\circ}$ or $86^{\circ}\alt\gamma\alt 151^{\circ}$ and $0^{\circ}\alt\delta\alt 75^{\circ} $ within 1$\sigma$ standard deviation. It is noted that if allowing the standard deviation of the data to be more than 1$\sigma$, the two solutions could approach to one solution with a much larger region for the phases $\gamma$ and $\delta$. Direct CP asymme try $a_{\epsilon''}^{(\pi^- K^+)}$ in $B\rarrow \pi^-K^+$ decay can be as large as the present experimental upper bound. Direct CP asymmetry $a_{\epsilon''}^{(\pi^+\pi^-)}$ in $B\rarrow \pi^-\pi^+$ decay can reach up to about 40% at 1$\sigma$ level.
[ { "created": "Tue, 22 Feb 2000 02:44:32 GMT", "version": "v1" }, { "created": "Mon, 28 Feb 2000 08:08:59 GMT", "version": "v2" }, { "created": "Wed, 1 Mar 2000 07:51:06 GMT", "version": "v3" } ]
2014-11-17
[ [ "Wu", "Yue-Liang", "" ], [ "Zhou", "Yu-Feng", "" ] ]
Assuming SU(3) symmetry for the strong phases in the four decay modes $B\rarrow \pi^-\pi^+, \pi^0 \pi^+, \pi^- K^+, \pi^- \bar{K}^0$ and ignoring the relative small electroweak penguin effects in those decays, the weak phase $\gamma$ and the strong phase $\delta$ can be determined in a model independent way by the CP-averaged branching ratios of the four decay modes. It appears that the current experimental data for $B\to \pi\pi$ and $\pi K$ decays prefer a negative value of $\cos\gamma\cos\delta$. By combining with the other constraints from $V_{ub}$, $B^{0}_{d,s}-\bar{B}^{0}_{d,s}$ mixings and indirect CP-violating parameter $\epsilon_K$ within the standard model, two favorable solutions for the phases $\gamma$ and $\delta$ are found to lie in the region: $35^{\circ}\alt\gamma\alt 62^{\circ}$ and $106^{\circ}\alt \delta \alt 180^{\circ}$ or $86^{\circ}\alt\gamma\alt 151^{\circ}$ and $0^{\circ}\alt\delta\alt 75^{\circ} $ within 1$\sigma$ standard deviation. It is noted that if allowing the standard deviation of the data to be more than 1$\sigma$, the two solutions could approach to one solution with a much larger region for the phases $\gamma$ and $\delta$. Direct CP asymme try $a_{\epsilon''}^{(\pi^- K^+)}$ in $B\rarrow \pi^-K^+$ decay can be as large as the present experimental upper bound. Direct CP asymmetry $a_{\epsilon''}^{(\pi^+\pi^-)}$ in $B\rarrow \pi^-\pi^+$ decay can reach up to about 40% at 1$\sigma$ level.
1808.09324
Sebastian Wild
Marco Hufnagel, Kai Schmidt-Hoberg, Sebastian Wild
BBN constraints on MeV-scale dark sectors. Part II. Electromagnetic decays
35 pages, 9 figures. v2: Included effect of FSR, conclusions unchanged. v3: matches published version
null
10.1088/1475-7516/2018/11/032
DESY 18-133
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Meta-stable dark sector particles decaying into electrons or photons may non-trivially change the Hubble rate, lead to entropy injection into the thermal bath of Standard Model particles and may also photodisintegrate light nuclei formed in the early universe. We study generic constraints from Big Bang Nucleosynthesis on such a setup, with a particular emphasis on MeV-scale particles which are neither fully relativistic nor non-relativistic during all times relevant for Big Bang Nucleosynthesis. We apply our results to a simple model of self-interacting dark matter with a light scalar mediator. This setup turns out to be severely constrained by these considerations in combination with direct dark matter searches and will be fully tested with the next generation of low-threshold direct detection experiments.
[ { "created": "Tue, 28 Aug 2018 14:29:56 GMT", "version": "v1" }, { "created": "Tue, 11 Sep 2018 12:29:21 GMT", "version": "v2" }, { "created": "Mon, 12 Nov 2018 16:20:36 GMT", "version": "v3" } ]
2018-11-28
[ [ "Hufnagel", "Marco", "" ], [ "Schmidt-Hoberg", "Kai", "" ], [ "Wild", "Sebastian", "" ] ]
Meta-stable dark sector particles decaying into electrons or photons may non-trivially change the Hubble rate, lead to entropy injection into the thermal bath of Standard Model particles and may also photodisintegrate light nuclei formed in the early universe. We study generic constraints from Big Bang Nucleosynthesis on such a setup, with a particular emphasis on MeV-scale particles which are neither fully relativistic nor non-relativistic during all times relevant for Big Bang Nucleosynthesis. We apply our results to a simple model of self-interacting dark matter with a light scalar mediator. This setup turns out to be severely constrained by these considerations in combination with direct dark matter searches and will be fully tested with the next generation of low-threshold direct detection experiments.
2003.06280
Vladimir Petrov A.
Vladimir A. Petrov
LHC Hunting the Odderon: Is It Really Catched?
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a short survey of recent LHC experiments and related theory topics concerning the Odderon problem.
[ { "created": "Fri, 13 Mar 2020 13:37:36 GMT", "version": "v1" }, { "created": "Tue, 17 Mar 2020 14:17:05 GMT", "version": "v2" } ]
2020-03-18
[ [ "Petrov", "Vladimir A.", "" ] ]
We give a short survey of recent LHC experiments and related theory topics concerning the Odderon problem.
0709.1030
Hans-Ulrich Martyn
Hans-Ulrich Martyn
Detection of long-lived staus and gravitinos at the ILC
Talk given at LCWS/ILC 2007 and SUSY 2007. Submitted for the SUSY07 proceedings
ECONF C0705302:SUS03,2007
null
null
hep-ph
null
A study is presented illustrating the excellent potential of future International Linear Collider (ILC) experiments to detect metastable staus $\stau$, measure precisely their mass and lifetime, and to determine the mass of the gravitino $\sG$ from the decay $\stau\to\tau\sG$, thus providing direct access to the gravitational coupling, respectively Planck scale.
[ { "created": "Fri, 7 Sep 2007 09:15:52 GMT", "version": "v1" } ]
2009-02-16
[ [ "Martyn", "Hans-Ulrich", "" ] ]
A study is presented illustrating the excellent potential of future International Linear Collider (ILC) experiments to detect metastable staus $\stau$, measure precisely their mass and lifetime, and to determine the mass of the gravitino $\sG$ from the decay $\stau\to\tau\sG$, thus providing direct access to the gravitational coupling, respectively Planck scale.
hep-ph/9909484
Yangmz
Taizo Muta and Mao-Zhi Yang
$\eta'-g^*-g$ Transition Form Factor with Gluon Content Contribution Tested
RevTex 10 pages, 4 figures, the version accepted for publication in Phys. Rev. D
Phys.Rev. D61 (2000) 054007
10.1103/PhysRevD.61.054007
null
hep-ph
null
We study the $\eta'-g^*-g$ transition form factor by using the $\eta'$ wave function constrained by the experimental data on the $\eta'-\gamma^*-\gamma$ transition form factor provided by CLEO and L3 . We also take into account the contribution of the possible gluonic content of the $\eta'$ meson.
[ { "created": "Thu, 23 Sep 1999 09:40:01 GMT", "version": "v1" }, { "created": "Mon, 8 Nov 1999 05:25:35 GMT", "version": "v2" } ]
2009-10-31
[ [ "Muta", "Taizo", "" ], [ "Yang", "Mao-Zhi", "" ] ]
We study the $\eta'-g^*-g$ transition form factor by using the $\eta'$ wave function constrained by the experimental data on the $\eta'-\gamma^*-\gamma$ transition form factor provided by CLEO and L3 . We also take into account the contribution of the possible gluonic content of the $\eta'$ meson.
hep-ph/0703142
Anjishnu Sarkar Mr.
Urjit A. Yajnik and Anjishnu Sarkar
Cosmology in a supersymmetric model with gauged $B-L$
18 pages. Minor changes in text, but conclusion remains same. Published in Phys. Rev. D
Phys.Rev.D76:025001,2007
10.1103/PhysRevD.76.025001
null
hep-ph
null
We consider salient cosmological features of a supersymmetric model which is Left-Right symmetric and therefore possessing gauged $B-L$ symmetry. The requirement of breaking parity and also obtaining charge preserving vacua introduces some unique features to this model (MSLRM), resulting in a preference for non-thermal Leptogenesis. Assuming that the model preserves TeV scale supersymmetry, we show that the vacuum structure generically possesses domain walls, which can serve two important purposes. They can signal a secondary inflation required to remove unwanted relics such as gravitino and moduli and also generate lepton asymmetry by a mechanism similar to electroweak baryogenesis. The requirement of disappearance of domain walls imposes constraints on the soft parameters of the theory, testable at the TeV scale. We also propose an alternative model with spontaneous parity violation (MSLR\rlap/P). Incorporating the same cosmological considerations in this case entails constraints on a different set of soft parameters.
[ { "created": "Tue, 13 Mar 2007 17:06:24 GMT", "version": "v1" }, { "created": "Tue, 3 Jul 2007 11:50:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Yajnik", "Urjit A.", "" ], [ "Sarkar", "Anjishnu", "" ] ]
We consider salient cosmological features of a supersymmetric model which is Left-Right symmetric and therefore possessing gauged $B-L$ symmetry. The requirement of breaking parity and also obtaining charge preserving vacua introduces some unique features to this model (MSLRM), resulting in a preference for non-thermal Leptogenesis. Assuming that the model preserves TeV scale supersymmetry, we show that the vacuum structure generically possesses domain walls, which can serve two important purposes. They can signal a secondary inflation required to remove unwanted relics such as gravitino and moduli and also generate lepton asymmetry by a mechanism similar to electroweak baryogenesis. The requirement of disappearance of domain walls imposes constraints on the soft parameters of the theory, testable at the TeV scale. We also propose an alternative model with spontaneous parity violation (MSLR\rlap/P). Incorporating the same cosmological considerations in this case entails constraints on a different set of soft parameters.
hep-ph/0206287
Einan Gardi
Einan Gardi (CERN)
Soft and Collinear Radiation and Factorization in Perturbation Theory and Beyond
11 pages, 6 postscript figures; talk presented at the XXXVII Rencontres de Moriond `QCD and high energy hadronic interactions', Les Arcs, France, and at the Workshop `Continuous Advances in QCD 2002/Arkadyfest', Minnesota
null
10.1142/9789812776310_0008
CERN-TH/2002-134
hep-ph
null
Power corrections to differential cross sections near a kinematic threshold are analysed by Dressed Gluon Exponentiation. Exploiting the factorization property of soft and collinear radiation, the dominant radiative corrections in the threshold region are resummed, yielding a renormalization-scale-invariant expression for the Sudakov exponent. The interplay between Sudakov logs and renormalons is clarified, and the necessity to resum the latter whenever power corrections are non-negligible is emphasized. The presence of power-suppressed ambiguities in the exponentiation kernel suggests that power corrections exponentiate as well. This leads to a non-perturbative factorization formula with non-trivial predictions on the structure of power corrections, which can be contrasted with the OPE. Two examples are discussed. The first is event-shape distributions in the two-jet region, where a wealth of precise data provides a strong motivation for the improved perturbative technique and an ideal situation to study hadronization. The second example is deep inelastic structure functions. In contrast to event shapes, structure functions have an OPE. However, since the OPE breaks down at large x, it does not provide a practical framework for the parametrization of power corrections. Performing a detailed analysis of twist 4 it is shown precisely how the twist-2 renormalon ambiguity eventually cancels out. This analysis provides a physical picture which substantiates the non-perturbative factorization conjecture.
[ { "created": "Thu, 27 Jun 2002 17:01:41 GMT", "version": "v1" } ]
2017-08-23
[ [ "Gardi", "Einan", "", "CERN" ] ]
Power corrections to differential cross sections near a kinematic threshold are analysed by Dressed Gluon Exponentiation. Exploiting the factorization property of soft and collinear radiation, the dominant radiative corrections in the threshold region are resummed, yielding a renormalization-scale-invariant expression for the Sudakov exponent. The interplay between Sudakov logs and renormalons is clarified, and the necessity to resum the latter whenever power corrections are non-negligible is emphasized. The presence of power-suppressed ambiguities in the exponentiation kernel suggests that power corrections exponentiate as well. This leads to a non-perturbative factorization formula with non-trivial predictions on the structure of power corrections, which can be contrasted with the OPE. Two examples are discussed. The first is event-shape distributions in the two-jet region, where a wealth of precise data provides a strong motivation for the improved perturbative technique and an ideal situation to study hadronization. The second example is deep inelastic structure functions. In contrast to event shapes, structure functions have an OPE. However, since the OPE breaks down at large x, it does not provide a practical framework for the parametrization of power corrections. Performing a detailed analysis of twist 4 it is shown precisely how the twist-2 renormalon ambiguity eventually cancels out. This analysis provides a physical picture which substantiates the non-perturbative factorization conjecture.
1012.5394
Ryuichiro Kitano
Hiraku Fukushima, Ryuichiro Kitano, Masahiro Yamaguchi
SuperTopcolor
20 pages
JHEP 1101:111,2011
10.1007/JHEP01(2011)111
TU-876
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a supersymmetric QCD with soft supersymmetry breaking terms as the dynamics for the electroweak symmetry breaking. We find various advantages compared to the non-supersymmetric models, such as a natural incorporation of the dynamical top-quark mass generation (the topcolor mechanism), the existence of a boson-pair condensation (the composite Higgs fields) and a large anomalous dimension of the composite operator to cure the flavor-changing-neutral-current and the S-parameter crises of the technicolor theories. The knowledge of the weakly coupled description (the Seiberg duality) enables us to perform perturbative computations in strongly coupled theories. Working in a large flavor theory where perturbative calculations are reliable in the dual description, one can find a stable vacuum with chiral symmetry breaking. The top/bottom quarks and also the Higgsinos obtain masses through a dynamically generated superpotential.
[ { "created": "Fri, 24 Dec 2010 12:29:42 GMT", "version": "v1" } ]
2011-01-28
[ [ "Fukushima", "Hiraku", "" ], [ "Kitano", "Ryuichiro", "" ], [ "Yamaguchi", "Masahiro", "" ] ]
We consider a supersymmetric QCD with soft supersymmetry breaking terms as the dynamics for the electroweak symmetry breaking. We find various advantages compared to the non-supersymmetric models, such as a natural incorporation of the dynamical top-quark mass generation (the topcolor mechanism), the existence of a boson-pair condensation (the composite Higgs fields) and a large anomalous dimension of the composite operator to cure the flavor-changing-neutral-current and the S-parameter crises of the technicolor theories. The knowledge of the weakly coupled description (the Seiberg duality) enables us to perform perturbative computations in strongly coupled theories. Working in a large flavor theory where perturbative calculations are reliable in the dual description, one can find a stable vacuum with chiral symmetry breaking. The top/bottom quarks and also the Higgsinos obtain masses through a dynamically generated superpotential.
hep-ph/9606459
Michel Tytgat
Robert D. Pisarski and Michel Tytgat
Cool Pions move at less than the speed of light
11 pages, latex + sprocl.sty, talk given at Continuous Advances in QCD'96, Minneapolis
null
null
null
hep-ph
null
At nonzero temperature, pions propagate through a thermal medium at less than the speed of light. About low temperature, this effect begins not at $\sim T^2$, but at next to leading order, $\sim T^4$. We also derive the generalization of the relation of Gell-Mann, Oakes, and Renner to nonzero temperature.
[ { "created": "Thu, 27 Jun 1996 19:29:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pisarski", "Robert D.", "" ], [ "Tytgat", "Michel", "" ] ]
At nonzero temperature, pions propagate through a thermal medium at less than the speed of light. About low temperature, this effect begins not at $\sim T^2$, but at next to leading order, $\sim T^4$. We also derive the generalization of the relation of Gell-Mann, Oakes, and Renner to nonzero temperature.
2104.01047
Hao Sun
DaZhuang He, Xuan Luo, YiLing Xie and Hao Sun
Theoretical study in the $\bar{B}^0 \to J/\psi \bar{K}^{*0} K^0$ and $\bar{B}^0 \to J/\psi f_1(1285)$ decays
5 figures, 7 pages
Phys. Rev. D 103, 094007 (2021)
10.1103/PhysRevD.103.094007
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the decay processes of $\bar{B}^0 \to J/\psi \bar{K}^{*0} K^0$ and $\bar{B}^0 \to J/\psi f_1(1285)$ to analyse the $f_1(1285)$ resonance. By the calculation within chiral unitary approach where $f_1(1285)$ resonance is dynamically generated from the $K^*\bar{K}-c.c.$ interaction, we find that the $\bar{K}^{*0} K^0$ invariant mass distribution has a clear broad peak. Such broad peak has been understood as the signal of the $f_1(1285)$. Finally, we obtain a theoretical result $R_t=\Gamma_{\bar{B}^0 \to J/\psi \bar{K}^{*0} K^0}/\Gamma_{\bar{B}^0 \to J/\psi f_1(1285)}$ which is expected to be compared with the experimental data.
[ { "created": "Fri, 2 Apr 2021 13:43:40 GMT", "version": "v1" }, { "created": "Tue, 6 Apr 2021 12:47:07 GMT", "version": "v2" } ]
2021-05-19
[ [ "He", "DaZhuang", "" ], [ "Luo", "Xuan", "" ], [ "Xie", "YiLing", "" ], [ "Sun", "Hao", "" ] ]
We study the decay processes of $\bar{B}^0 \to J/\psi \bar{K}^{*0} K^0$ and $\bar{B}^0 \to J/\psi f_1(1285)$ to analyse the $f_1(1285)$ resonance. By the calculation within chiral unitary approach where $f_1(1285)$ resonance is dynamically generated from the $K^*\bar{K}-c.c.$ interaction, we find that the $\bar{K}^{*0} K^0$ invariant mass distribution has a clear broad peak. Such broad peak has been understood as the signal of the $f_1(1285)$. Finally, we obtain a theoretical result $R_t=\Gamma_{\bar{B}^0 \to J/\psi \bar{K}^{*0} K^0}/\Gamma_{\bar{B}^0 \to J/\psi f_1(1285)}$ which is expected to be compared with the experimental data.
1303.1397
German F.R. Sborlini
Daniel de Florian, Nerina Fidanza, R.J. Hern\'andez-Pinto, Javier Mazzitelli, Yamila Rotstein Habarnau and German F.R. Sborlini
A complete O(alpha_S^2) calculation of the signal-background interference for the Higgs diphoton decay channel
8 pages, 5 figures
Eur. Phys. J. C (2013) 73:2387
10.1140/epjc/s10052-013-2387-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the full ${\cal O}(\as^2)$ computation of the interference effects between the Higgs diphoton signal and the continuum background at the LHC. While the main contribution to the interference originates on the $gg$ partonic subprocess, we find that the corrections from the $qg$ and $q\bar{q}$ channels amount up to 35% of it. We discuss the effect of these new subprocesses in the shift of the diphoton invariant mass peak recently reported by S. Martin in Ref.\cite{Martin:2012xc}.
[ { "created": "Wed, 6 Mar 2013 17:32:28 GMT", "version": "v1" } ]
2013-05-14
[ [ "de Florian", "Daniel", "" ], [ "Fidanza", "Nerina", "" ], [ "Hernández-Pinto", "R. J.", "" ], [ "Mazzitelli", "Javier", "" ], [ "Habarnau", "Yamila Rotstein", "" ], [ "Sborlini", "German F. R.", "" ] ]
We present the full ${\cal O}(\as^2)$ computation of the interference effects between the Higgs diphoton signal and the continuum background at the LHC. While the main contribution to the interference originates on the $gg$ partonic subprocess, we find that the corrections from the $qg$ and $q\bar{q}$ channels amount up to 35% of it. We discuss the effect of these new subprocesses in the shift of the diphoton invariant mass peak recently reported by S. Martin in Ref.\cite{Martin:2012xc}.
2205.09484
Francesca Dordei
M. Atzori Corona, M. Cadeddu, N. Cargioli, F. Dordei, C. Giunti, Y.F. Li, C. A. Ternes, and Y.Y. Zhang
Impact of the Dresden-II and COHERENT neutrino scattering data on neutrino electromagnetic properties and electroweak physics
Matches the published version. 33 pages, 11 figures
JHEP 09 (2022) 164
10.1007/JHEP09(2022)164
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) represents a powerful tool to investigate key electroweak physics parameters and neutrino properties since its first observation in 2017 by the COHERENT experiment exploiting the spallation neutron source at Oak Ridge National Laboratory. In light of the recent detection of such a process with antineutrinos produced by the Dresden-II reactor scattering off a germanium detector, we revisit the limits so far set on the neutrino magnetic moments, charge radii and millicharges as well as on the weak mixing angle. In order to do so, we also include the contribution of elastic neutrino-electron scattering, whose effect becomes non negligible in some beyond the Standard Model theories. By using different hypotheses for the germanium quenching factor and the reactor antineutrino flux, we provide a measurement of the weak mixing angle at the low-energy scale of the Dresden-II reactor experiment and, thanks to a combined analysis with the latest cesium iodide and argon data set released by the COHERENT Collaboration, we deliver updated limits for the neutrino electromagnetic properties. Interestingly, we are able to set a new best upper limit on the electron neutrino charge radius and significantly improve the other CE$\nu$NS-related limits on the neutrino electric charge and magnetic moment.
[ { "created": "Thu, 19 May 2022 11:45:19 GMT", "version": "v1" }, { "created": "Tue, 14 Mar 2023 10:52:02 GMT", "version": "v2" } ]
2023-03-15
[ [ "Corona", "M. Atzori", "" ], [ "Cadeddu", "M.", "" ], [ "Cargioli", "N.", "" ], [ "Dordei", "F.", "" ], [ "Giunti", "C.", "" ], [ "Li", "Y. F.", "" ], [ "Ternes", "C. A.", "" ], [ "Zhang", "Y. Y.", "" ] ]
Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) represents a powerful tool to investigate key electroweak physics parameters and neutrino properties since its first observation in 2017 by the COHERENT experiment exploiting the spallation neutron source at Oak Ridge National Laboratory. In light of the recent detection of such a process with antineutrinos produced by the Dresden-II reactor scattering off a germanium detector, we revisit the limits so far set on the neutrino magnetic moments, charge radii and millicharges as well as on the weak mixing angle. In order to do so, we also include the contribution of elastic neutrino-electron scattering, whose effect becomes non negligible in some beyond the Standard Model theories. By using different hypotheses for the germanium quenching factor and the reactor antineutrino flux, we provide a measurement of the weak mixing angle at the low-energy scale of the Dresden-II reactor experiment and, thanks to a combined analysis with the latest cesium iodide and argon data set released by the COHERENT Collaboration, we deliver updated limits for the neutrino electromagnetic properties. Interestingly, we are able to set a new best upper limit on the electron neutrino charge radius and significantly improve the other CE$\nu$NS-related limits on the neutrino electric charge and magnetic moment.
hep-ph/0111275
Hiroshi Yokota
Yuko Fueki, Hisao Nakkagawa, Hiroshi Yokota, Koji Yoshida
N-Point Vertex Functions, Ward-Takahashi Identities and Dyson-Schwinger Equations in Thermal QCD/QED in the Real Time Hard-Thermal-Loop Approximation
20 pages with 11 figures (ps file), revtex4
Prog.Theor.Phys.107:759-784,2002
10.1143/PTP.107.759
null
hep-ph
null
In this paper we calculated the n-point hard-thermal-loop (HTL) vertex functions in QCD/QED for n= 2, 3 and 4 in the physical representation in the real time formalism (RTF). The result showed that the n-point HTL vertex functions can be classified into two groups, a) those with odd numbers of external retarded indices, and b) the others with even numbers of external retarded indices. The n-point HTL vertex functions with one retarded index, which obviously belong to the first group a), are nothing but the HTL vertex functions that appear in the imaginary time formalism (ITF), and vise versa. All the HTL vertex functions belonging to the first group a) are of $O(g^2T^2)$ , and satisfy among them the simple QED-type Ward-Takahashi identities, as in the ITF. Those vertex functions belonging to the second group b) never appear in the ITF, namely their existence is characteristic of the RTF, and their HTL's have the high temperature behavior of $O(g^2T^3)$, one-power of T higher than usual. Despite this difference we could verify that those HTL vertex functions belonging to the second group b) also satisfy among themselves the QED-type Ward-Takahashi identities, thus guaranteeing the gauge invariance of the HTL's in the real time thermal QCD/QED.
[ { "created": "Thu, 22 Nov 2001 09:01:37 GMT", "version": "v1" } ]
2011-04-20
[ [ "Fueki", "Yuko", "" ], [ "Nakkagawa", "Hisao", "" ], [ "Yokota", "Hiroshi", "" ], [ "Yoshida", "Koji", "" ] ]
In this paper we calculated the n-point hard-thermal-loop (HTL) vertex functions in QCD/QED for n= 2, 3 and 4 in the physical representation in the real time formalism (RTF). The result showed that the n-point HTL vertex functions can be classified into two groups, a) those with odd numbers of external retarded indices, and b) the others with even numbers of external retarded indices. The n-point HTL vertex functions with one retarded index, which obviously belong to the first group a), are nothing but the HTL vertex functions that appear in the imaginary time formalism (ITF), and vise versa. All the HTL vertex functions belonging to the first group a) are of $O(g^2T^2)$ , and satisfy among them the simple QED-type Ward-Takahashi identities, as in the ITF. Those vertex functions belonging to the second group b) never appear in the ITF, namely their existence is characteristic of the RTF, and their HTL's have the high temperature behavior of $O(g^2T^3)$, one-power of T higher than usual. Despite this difference we could verify that those HTL vertex functions belonging to the second group b) also satisfy among themselves the QED-type Ward-Takahashi identities, thus guaranteeing the gauge invariance of the HTL's in the real time thermal QCD/QED.
hep-ph/0108088
Gabriel Lopez Castro
G. Calderon and G. Lopez Castro
Convolution formula and finite W boson width effects in the top quark width
10 pages, published version
Int.J.Mod.Phys.A23:3525-3533,2008
10.1142/S0217751X08041578
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the standard model, the top quark decay width \Gamma_t is computed from the exclusive t -> bW decay. We argue in favor of using the three body decays t-> bf_i\bar{f}_j to compute \Gamma_t as a sum over these exclusive modes. As dictated by the S-matrix theory, these three body decays of the top quark involve only asymptotic states and incorporate the width of the W boson resonance in a natural way. The convolution formula (CF) commonly used to include the finite width effects is found to be valid, in the general case, when the intermediate resonance couples to a conserved current (limit of massless fermions in the case of W bosons). The relation Gamma_t=\Gamma(t-> bW) is recovered by taking the limit of massless fermions followed by the W boson narrow width approximation. Although both calculations of \Gamma_t are different at the formal level, their results would differ only by tiny effects induced by light fermion masses and higher order radiative corrections.
[ { "created": "Thu, 9 Aug 2001 18:28:30 GMT", "version": "v1" }, { "created": "Fri, 3 Aug 2007 15:26:49 GMT", "version": "v2" }, { "created": "Mon, 27 Oct 2008 18:44:24 GMT", "version": "v3" } ]
2010-01-11
[ [ "Calderon", "G.", "" ], [ "Castro", "G. Lopez", "" ] ]
In the standard model, the top quark decay width \Gamma_t is computed from the exclusive t -> bW decay. We argue in favor of using the three body decays t-> bf_i\bar{f}_j to compute \Gamma_t as a sum over these exclusive modes. As dictated by the S-matrix theory, these three body decays of the top quark involve only asymptotic states and incorporate the width of the W boson resonance in a natural way. The convolution formula (CF) commonly used to include the finite width effects is found to be valid, in the general case, when the intermediate resonance couples to a conserved current (limit of massless fermions in the case of W bosons). The relation Gamma_t=\Gamma(t-> bW) is recovered by taking the limit of massless fermions followed by the W boson narrow width approximation. Although both calculations of \Gamma_t are different at the formal level, their results would differ only by tiny effects induced by light fermion masses and higher order radiative corrections.
hep-ph/9909349
Scott Thomas
Uri Sarid and Scott Thomas
Mesino - Antimesino Oscillations
4 pages, 1 figure, LaTex
Phys.Rev.Lett. 85 (2000) 1178-1181
10.1103/PhysRevLett.85.1178
UND-HEP-98-US01, SU-ITP-98-70
hep-ph
null
The phenomenological implications of supersymmetric theories with low scale supersymmetry breaking and a squark as the lightest standard model superpartner are investigated. Such squarks hadronize with light quarks, forming sbaryons and mesinos before decaying. Production of these supersymmetric bound states at a high energy collider can lead to displaced jets with large negative impact parameter. Neutral mesino - antimesino oscillations are not forbidden by any symmetry and can occur at observable rates with distinctive signatures. Stop mesino - antimesino oscillations would give a sensitive probe of up-type sflavor violation in the squark sector, and can provide a discovery channel for supersymmetry through events with a same-sign top-top topology.
[ { "created": "Mon, 13 Sep 1999 19:01:02 GMT", "version": "v1" } ]
2009-10-31
[ [ "Sarid", "Uri", "" ], [ "Thomas", "Scott", "" ] ]
The phenomenological implications of supersymmetric theories with low scale supersymmetry breaking and a squark as the lightest standard model superpartner are investigated. Such squarks hadronize with light quarks, forming sbaryons and mesinos before decaying. Production of these supersymmetric bound states at a high energy collider can lead to displaced jets with large negative impact parameter. Neutral mesino - antimesino oscillations are not forbidden by any symmetry and can occur at observable rates with distinctive signatures. Stop mesino - antimesino oscillations would give a sensitive probe of up-type sflavor violation in the squark sector, and can provide a discovery channel for supersymmetry through events with a same-sign top-top topology.