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1609.08895
Dennis Loose
Gudrun Hiller, Dennis Loose, Kay Sch\"onwald
Leptoquark Flavor Patterns & B Decay Anomalies
23 pages plus references and appendices, 2 figures, v2: typos fixed, clarifications and references added; conclusions unchanged
null
10.1007/JHEP12(2016)027
DO-TH 16/17
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavor symmetries that explain masses and mixings of the standard model fermions dictate flavor patterns for the couplings of scalar and vector leptoquarks to the standard model fermions. A generic feature is that couplings to $SU(2)$-doublet leptons are suppressed at least by one spurion of the discrete non-abelian symmetry breaking, responsible for neutrino mixing, while couplings to charged lepton singlets can be order one. We obtain testable patterns including those that predominantly couple to a single lepton flavor, or two, or in a skewed way. They induce lepton non-universality, which we contrast to current anomalies in $B$-decays. We find maximal effects in $R_{D}$ and $R_{D^*}$ at the level of $\sim$10 percent and few percent, respectively, while leptoquark effects in $R_{K^{(*)}}$ can reach order few$\times 10$ percent. Predictions for charm and kaon decays and $\mu-e$ conversion are worked out.
[ { "created": "Wed, 28 Sep 2016 12:56:53 GMT", "version": "v1" }, { "created": "Mon, 5 Dec 2016 13:59:01 GMT", "version": "v2" } ]
2017-01-04
[ [ "Hiller", "Gudrun", "" ], [ "Loose", "Dennis", "" ], [ "Schönwald", "Kay", "" ] ]
Flavor symmetries that explain masses and mixings of the standard model fermions dictate flavor patterns for the couplings of scalar and vector leptoquarks to the standard model fermions. A generic feature is that couplings to $SU(2)$-doublet leptons are suppressed at least by one spurion of the discrete non-abelian symmetry breaking, responsible for neutrino mixing, while couplings to charged lepton singlets can be order one. We obtain testable patterns including those that predominantly couple to a single lepton flavor, or two, or in a skewed way. They induce lepton non-universality, which we contrast to current anomalies in $B$-decays. We find maximal effects in $R_{D}$ and $R_{D^*}$ at the level of $\sim$10 percent and few percent, respectively, while leptoquark effects in $R_{K^{(*)}}$ can reach order few$\times 10$ percent. Predictions for charm and kaon decays and $\mu-e$ conversion are worked out.
2103.14611
Azadeh Maleknejad
Azadeh Maleknejad
Chiral Anomaly in SU(2)${}_R$-Axion Inflation and the New Prediction for Particle Cosmology
28+20 Pages, 15 Figs
J. High Energ. Phys. 2021, 113 (2021)
10.1007/JHEP06(2021)113
CERN-TH-2021-034
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Upon embedding the axion-inflation in the minimal left-right symmetric gauge extension of the SM with gauge group $SU(2)_L\times SU(2)_R \times U(1)_{B-L}$, [arXiv:2012.11516] proposed a new particle physics model for inflation. In this work, we present a more detailed analysis. As a compelling consequence, this setup provides a new mechanism for simultaneous baryogenesis and right-handed neutrino creation by the chiral anomaly of $W_R$ in inflation. The lightest right-handed neutrino is the dark matter candidate. This setup has two unknown fundamental scales, i.e., the scale of inflation and left-right symmetry breaking $SU(2)_R\times U(1)_{B-L}\rightarrow U(1)_{Y}$. Sufficient matter creation demands the left-right symmetry breaking scale happens shortly after the end of inflation. Interestingly, it prefers left-right symmetry breaking scales above $10^{10}~GeV$, which is in the range suggested by the non-supersymmetric SO(10) Grand Unified Theory with an intermediate left-right symmetry scale. Although $W_R$ gauge field generates equal amounts of right-handed baryons and leptons in inflation, i.e. $B-L=0$, in the Standard Model sub-sector $B-L_{SM}\neq 0$. A key aspect of this setup is that $SU(2)_R$ sphalerons are never in equilibrium, and the primordial $B-L_{SM}$ is conserved by the Standard Model interactions. This setup yields a deep connection between CP violation in physics of inflation and matter creation (visible and dark); hence it can naturally explain the observed coincidences among cosmological parameters, i.e., $\eta_{B}\simeq 0.3 P_{\zeta}$ and $\Omega_{DM}\simeq 5\Omega_{B}$. The $SU(2)_R$-axion inflation comes with a cosmological smoking gun; chiral, non-Gaussian, and blue-tilted gravitational wave background, which can be probed by future CMB missions and laser interferometer detectors.
[ { "created": "Fri, 26 Mar 2021 17:27:55 GMT", "version": "v1" } ]
2021-10-26
[ [ "Maleknejad", "Azadeh", "" ] ]
Upon embedding the axion-inflation in the minimal left-right symmetric gauge extension of the SM with gauge group $SU(2)_L\times SU(2)_R \times U(1)_{B-L}$, [arXiv:2012.11516] proposed a new particle physics model for inflation. In this work, we present a more detailed analysis. As a compelling consequence, this setup provides a new mechanism for simultaneous baryogenesis and right-handed neutrino creation by the chiral anomaly of $W_R$ in inflation. The lightest right-handed neutrino is the dark matter candidate. This setup has two unknown fundamental scales, i.e., the scale of inflation and left-right symmetry breaking $SU(2)_R\times U(1)_{B-L}\rightarrow U(1)_{Y}$. Sufficient matter creation demands the left-right symmetry breaking scale happens shortly after the end of inflation. Interestingly, it prefers left-right symmetry breaking scales above $10^{10}~GeV$, which is in the range suggested by the non-supersymmetric SO(10) Grand Unified Theory with an intermediate left-right symmetry scale. Although $W_R$ gauge field generates equal amounts of right-handed baryons and leptons in inflation, i.e. $B-L=0$, in the Standard Model sub-sector $B-L_{SM}\neq 0$. A key aspect of this setup is that $SU(2)_R$ sphalerons are never in equilibrium, and the primordial $B-L_{SM}$ is conserved by the Standard Model interactions. This setup yields a deep connection between CP violation in physics of inflation and matter creation (visible and dark); hence it can naturally explain the observed coincidences among cosmological parameters, i.e., $\eta_{B}\simeq 0.3 P_{\zeta}$ and $\Omega_{DM}\simeq 5\Omega_{B}$. The $SU(2)_R$-axion inflation comes with a cosmological smoking gun; chiral, non-Gaussian, and blue-tilted gravitational wave background, which can be probed by future CMB missions and laser interferometer detectors.
1604.05728
Adam Martin
Adam Martin, Tuhin S. Roy
A Cautionary Tale of Mis-measured Tails from $q/g$ Bias
20 pages, 10 figures. Version published in Phys. Rev. D
Phys. Rev. D 94, 014003 (2016)
10.1103/PhysRevD.94.014003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Jet substructure techniques such as subjet $p_T$-asymmetry, mass-drop, and grooming have become powerful and widely used tools in experimental searches at the LHC. While these tools provide much-desired handles to separate signal from background, they can introduce unexpected mass scales into the analysis. These scales may be misinterpreted as excesses if these are not correctly incorporated into background modeling. As an example, we study the ATLAS hadronic di-$W/Z$ resonance search. There, we find that the substructure analysis -- in particular the combination of a subjet asymmetry cut with the requirement on the number of tracks within a jet -- induces a mass scale where the dominant partonic subprocess in the background changes from $pp \to g \!+\! q/\bar q$ to $pp \to q\bar{q}$. In light of this scale, modeling the QCD background using a simple smooth function with monotonically decreasing slope appears insufficient.
[ { "created": "Tue, 19 Apr 2016 20:00:36 GMT", "version": "v1" }, { "created": "Fri, 15 Jul 2016 23:48:45 GMT", "version": "v2" } ]
2016-07-19
[ [ "Martin", "Adam", "" ], [ "Roy", "Tuhin S.", "" ] ]
Jet substructure techniques such as subjet $p_T$-asymmetry, mass-drop, and grooming have become powerful and widely used tools in experimental searches at the LHC. While these tools provide much-desired handles to separate signal from background, they can introduce unexpected mass scales into the analysis. These scales may be misinterpreted as excesses if these are not correctly incorporated into background modeling. As an example, we study the ATLAS hadronic di-$W/Z$ resonance search. There, we find that the substructure analysis -- in particular the combination of a subjet asymmetry cut with the requirement on the number of tracks within a jet -- induces a mass scale where the dominant partonic subprocess in the background changes from $pp \to g \!+\! q/\bar q$ to $pp \to q\bar{q}$. In light of this scale, modeling the QCD background using a simple smooth function with monotonically decreasing slope appears insufficient.
2104.11155
Moha Ouali
M. Ouhammou, M. Ouali, S. Taj, and B. Manaut
Higgs-strahlung boson production in the presence of a circularly polarized laser field
17 pages, 11 figures
Laser Phys. Lett. 18 (2021) 076002
10.1088/1612-202X/ac0919
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In the framework of the electroweak standard model, we investigated, in the center of mass frame, the Higgs boson production in the presence of an intense laser field via ${e}^{+} {e}^{-}$ annihilation $({e}^{+} {e}^{-}\rightarrow ZH)$. By comparing our results with those obtained by Djouadi \cite{1} for laser-free process, we show that the circularly polarized laser field affects significantly the $s$-channel Higgs boson production. We find that for a given number of exchanged photons, laser field strength and frequency, the total cross section decreases by several orders of magnitude. These effects of laser field on cross section are found to be consistent with what was found for muon pair production via QED process in the presence of a circularly polarized laser field \cite{2}.
[ { "created": "Wed, 21 Apr 2021 14:13:24 GMT", "version": "v1" } ]
2021-07-02
[ [ "Ouhammou", "M.", "" ], [ "Ouali", "M.", "" ], [ "Taj", "S.", "" ], [ "Manaut", "B.", "" ] ]
In the framework of the electroweak standard model, we investigated, in the center of mass frame, the Higgs boson production in the presence of an intense laser field via ${e}^{+} {e}^{-}$ annihilation $({e}^{+} {e}^{-}\rightarrow ZH)$. By comparing our results with those obtained by Djouadi \cite{1} for laser-free process, we show that the circularly polarized laser field affects significantly the $s$-channel Higgs boson production. We find that for a given number of exchanged photons, laser field strength and frequency, the total cross section decreases by several orders of magnitude. These effects of laser field on cross section are found to be consistent with what was found for muon pair production via QED process in the presence of a circularly polarized laser field \cite{2}.
0803.2992
German Rodrigo
German Rodrigo
Axigluon signatures at hadron colliders
Presented at 8th International Symposium on Radiative Corrections (RADCOR07), 1-5 October 2007, Florence, Italy
PoSRADCOR2007:010,2007
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axigluons are colored heavy neutral gauge boson that are predicted by some theories. The most important model-independent manifestation of axigluons is the generation of a forward--backward asymmetry in top-antitop quark production at $p\bar{p}$ collisions which originates from the charge asymmetry. We update our previous analysis for the inclusive QCD induced forward--backward asymmetry and define a new observable which is more sensitive to the effect than the forward--backward asymmetry. We find a lower limit of 1.4 TeV at 90% C.L. on the axigluon mass from recent measurements of the asymmetry at Tevatron, and extend the analysis to LHC in suitably selected samples. Like at Tevatron, the charge asymmetry can probe larger values of the axigluon mass than the dijet mass distribution.
[ { "created": "Thu, 20 Mar 2008 13:09:50 GMT", "version": "v1" } ]
2008-11-26
[ [ "Rodrigo", "German", "" ] ]
Axigluons are colored heavy neutral gauge boson that are predicted by some theories. The most important model-independent manifestation of axigluons is the generation of a forward--backward asymmetry in top-antitop quark production at $p\bar{p}$ collisions which originates from the charge asymmetry. We update our previous analysis for the inclusive QCD induced forward--backward asymmetry and define a new observable which is more sensitive to the effect than the forward--backward asymmetry. We find a lower limit of 1.4 TeV at 90% C.L. on the axigluon mass from recent measurements of the asymmetry at Tevatron, and extend the analysis to LHC in suitably selected samples. Like at Tevatron, the charge asymmetry can probe larger values of the axigluon mass than the dijet mass distribution.
2407.21100
Marco Ardu
Marco Ardu, Moinul Hossain Rahat, Nicola Valori and Oscar Vives
Electric Dipole Moments as indirect probes of Dark Sectors
18 Pages + Appendices. Comments welcome!
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Dark sectors provide beyond Standard Model scenarios which can address unresolved puzzles, such as the observed dark matter abundance or the baryon asymmetry of the Universe. A naturally small portal to the dark sector is obtained if dark-sector interactions stem from a non-Abelian hidden gauge group that couples through kinetic mixing with the hypercharge boson. In this work, we investigate the phenomenology of such a portal of dimension five in the presence of CP violation, focusing on its signatures in fermion electric dipole moments. We show that, currently unbounded regions of the parameter space from dark photon searches can be indirectly probed with upcoming electron dipole moment experiments for dark boson masses in the range $1-100$ GeV. We also discuss two particular scenarios where a $SU(2)_D$ dark gauge group spontaneously breaks into either an Abelian $U(1)_D$ or nothing. In both cases, we show that potentially observable electron dipole moments can be produced in vast regions of the parameter space compatible with current experimental constraints and observed dark matter abundance.
[ { "created": "Tue, 30 Jul 2024 18:00:01 GMT", "version": "v1" } ]
2024-08-01
[ [ "Ardu", "Marco", "" ], [ "Rahat", "Moinul Hossain", "" ], [ "Valori", "Nicola", "" ], [ "Vives", "Oscar", "" ] ]
Dark sectors provide beyond Standard Model scenarios which can address unresolved puzzles, such as the observed dark matter abundance or the baryon asymmetry of the Universe. A naturally small portal to the dark sector is obtained if dark-sector interactions stem from a non-Abelian hidden gauge group that couples through kinetic mixing with the hypercharge boson. In this work, we investigate the phenomenology of such a portal of dimension five in the presence of CP violation, focusing on its signatures in fermion electric dipole moments. We show that, currently unbounded regions of the parameter space from dark photon searches can be indirectly probed with upcoming electron dipole moment experiments for dark boson masses in the range $1-100$ GeV. We also discuss two particular scenarios where a $SU(2)_D$ dark gauge group spontaneously breaks into either an Abelian $U(1)_D$ or nothing. In both cases, we show that potentially observable electron dipole moments can be produced in vast regions of the parameter space compatible with current experimental constraints and observed dark matter abundance.
0909.1337
Ivo de Medeiros Varzielas
Ivo de Medeiros Varzielas
Neutrino Mixing in Unified Extended Seesaw Model
Proceedings submission for SUSY09, 4 pages, 1 figure
AIP Conf.Proc.1200:944-947,2010
10.1063/1.3327770
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The seesaw mechanism can play a key role in the generation of the leptonic mixing in unified models. We consider an unified model with a family symmetry and extended seesaw, and obtain viable fermion masses and mixing (leptonic mixing is close to tri-bi-maximal).
[ { "created": "Tue, 8 Sep 2009 14:37:19 GMT", "version": "v1" } ]
2015-05-14
[ [ "Varzielas", "Ivo de Medeiros", "" ] ]
The seesaw mechanism can play a key role in the generation of the leptonic mixing in unified models. We consider an unified model with a family symmetry and extended seesaw, and obtain viable fermion masses and mixing (leptonic mixing is close to tri-bi-maximal).
hep-ph/0602229
Andreas Karch
Andreas Karch, Emanuel Katz, Dam T. Son, Mikhail A. Stephanov
Linear Confinement and AdS/QCD
14 pages, 1 figure
Phys.Rev.D74:015005,2006
10.1103/PhysRevD.74.015005
BUHEP-06-02, INT-PUB 06-04
hep-ph hep-th
null
In a theory with linear confinement, such as QCD, the masses squared m^2 of mesons with high spin S or high radial excitation number n are expected, from semiclassical arguments, to grow linearly with S and n. We show that this behavior can be reproduced within a putative 5-dimensional theory holographically dual to QCD (AdS/QCD). With the assumption that such a dual theory exists and describes highly excited mesons as well, we show that asymptotically linear m^2 spectrum translates into a strong constraint on the INFRARED behavior of that theory. In the simplest model which obeys such a constraint we find m^2 ~ (n+S).
[ { "created": "Sun, 26 Feb 2006 06:22:55 GMT", "version": "v1" }, { "created": "Wed, 26 Jul 2006 01:12:33 GMT", "version": "v2" } ]
2008-11-26
[ [ "Karch", "Andreas", "" ], [ "Katz", "Emanuel", "" ], [ "Son", "Dam T.", "" ], [ "Stephanov", "Mikhail A.", "" ] ]
In a theory with linear confinement, such as QCD, the masses squared m^2 of mesons with high spin S or high radial excitation number n are expected, from semiclassical arguments, to grow linearly with S and n. We show that this behavior can be reproduced within a putative 5-dimensional theory holographically dual to QCD (AdS/QCD). With the assumption that such a dual theory exists and describes highly excited mesons as well, we show that asymptotically linear m^2 spectrum translates into a strong constraint on the INFRARED behavior of that theory. In the simplest model which obeys such a constraint we find m^2 ~ (n+S).
hep-ph/9502356
null
K. Goulianos (The Rockefeller University)
POMERON FLUX RENORMALIZATION IN SOFT AND HARD DIFFRACTION
14 pages, 3 EPS figures tarred, compressed, uuencoded
Phys.Lett.B358:379-388,1995; Erratum-ibid.B363:268,1995
10.1016/0370-2693(95)01023-J
RU-95/E-06
hep-ph
null
While the main features of elastic, diffractive and total cross sections are described well by Regge theory, the measured rise of the proton-(anti)proton single diffraction dissociation cross section with energy is considerably smaller than the theoretical prediction based on factorization and a constant triple-pomeron coupling. The observed energy dependence is obtained by renormalizing the pomeron flux "carried" by a nucleon to unity. Double diffraction and double pomeron exchange cross sections are reevaluated and compared to data, and a new interpretation of hard diffraction results emerges in which the hard pomeron obeys the momentum sum rule.
[ { "created": "Mon, 20 Feb 1995 22:47:24 GMT", "version": "v1" } ]
2010-05-12
[ [ "Goulianos", "K.", "", "The Rockefeller University" ] ]
While the main features of elastic, diffractive and total cross sections are described well by Regge theory, the measured rise of the proton-(anti)proton single diffraction dissociation cross section with energy is considerably smaller than the theoretical prediction based on factorization and a constant triple-pomeron coupling. The observed energy dependence is obtained by renormalizing the pomeron flux "carried" by a nucleon to unity. Double diffraction and double pomeron exchange cross sections are reevaluated and compared to data, and a new interpretation of hard diffraction results emerges in which the hard pomeron obeys the momentum sum rule.
2005.01842
Raghav Kunnawalkam Elayavalli
Jana Biel\v{c}\'ikov\'a, Raghav Kunnawalkam Elayavalli, Georgy Ponimatkin, J\"orn H. Putschke and Josef Sivic
Identifying Heavy-Flavor Jets Using Vectors of Locally Aggregated Descriptors
18 pages, 6 figures and 3 tables. Accepted by JINST
null
10.1088/1748-0221/16/03/P03017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Jets of collimated particles serve a multitude of purposes in high energy collisions. Recently, studies of jet interaction with the quark-gluon plasma (QGP) created in high energy heavy ion collisions are of growing interest, particularly towards understanding partonic energy loss in the QGP medium and its related modifications of the jet shower and fragmentation. Since the QGP is a colored medium, the extent of jet quenching and consequently, the transport properties of the medium are expected to be sensitive to fundamental properties of the jets such as the flavor of the parton that initiates the jet. Identifying the jet flavor enables an extraction of the mass dependence in jet-QGP interactions. We present a novel approach to tagging heavy-flavor jets at collider experiments utilizing the information contained within jet constituents via the \texttt{JetVLAD} model architecture. We show the performance of this model in proton-proton collisions at center of mass energy $\sqrt{s} = 200$ GeV as characterized by common metrics and showcase its ability to extract high purity heavy-flavor jet sample at various jet momenta and realistic production cross-sections including a brief discussion on the impact of out-of-time pile-up. Such studies open new opportunities for future high purity heavy-flavor measurements at jet energies accessible at current and future collider experiments.
[ { "created": "Mon, 4 May 2020 20:48:35 GMT", "version": "v1" }, { "created": "Mon, 22 Jun 2020 19:58:31 GMT", "version": "v2" }, { "created": "Thu, 27 Aug 2020 17:56:37 GMT", "version": "v3" }, { "created": "Thu, 7 Jan 2021 15:59:41 GMT", "version": "v4" } ]
2021-03-24
[ [ "Bielčíková", "Jana", "" ], [ "Elayavalli", "Raghav Kunnawalkam", "" ], [ "Ponimatkin", "Georgy", "" ], [ "Putschke", "Jörn H.", "" ], [ "Sivic", "Josef", "" ] ]
Jets of collimated particles serve a multitude of purposes in high energy collisions. Recently, studies of jet interaction with the quark-gluon plasma (QGP) created in high energy heavy ion collisions are of growing interest, particularly towards understanding partonic energy loss in the QGP medium and its related modifications of the jet shower and fragmentation. Since the QGP is a colored medium, the extent of jet quenching and consequently, the transport properties of the medium are expected to be sensitive to fundamental properties of the jets such as the flavor of the parton that initiates the jet. Identifying the jet flavor enables an extraction of the mass dependence in jet-QGP interactions. We present a novel approach to tagging heavy-flavor jets at collider experiments utilizing the information contained within jet constituents via the \texttt{JetVLAD} model architecture. We show the performance of this model in proton-proton collisions at center of mass energy $\sqrt{s} = 200$ GeV as characterized by common metrics and showcase its ability to extract high purity heavy-flavor jet sample at various jet momenta and realistic production cross-sections including a brief discussion on the impact of out-of-time pile-up. Such studies open new opportunities for future high purity heavy-flavor measurements at jet energies accessible at current and future collider experiments.
hep-ph/0411300
Bernd Kniehl
B.A. Kniehl, G. Kramer, M. Maniatis
Inclusive Production of Single Hadrons with Finite Transverse Momenta in Deep-Inelastic Scattering at Next-to-Leading Order
26 pages, 12 figures
Nucl.Phys.B711:345-366,2005; Erratum-ibid.B720:231,2005
10.1016/j.nuclphysb.2005.01.031 10.1016/j.nuclphysb.2005.05.017
DESY 04-224
hep-ph hep-ex
null
We calculate the cross section for the inclusive production of single hadrons with finite transverse momenta in deep-inelastic scattering at next-to-leading order (NLO), i.e. through O(alpha_s^2), in the parton model of QCD endowed with non-perturbative parton distribution functions (PDFs) and fragmentation functions (FFs). The NLO correction is found to produce a sizeable enhancement in cross section, of up to one order of magnitude, bringing the theoretical prediction to good agreement with recent measurements for neutral pions and charged hadrons at DESY HERA. This provides a useful test for the universality and the scaling violations of the FFs predicted by the factorization theorem. Such comparisons can also be used to constrain the gluon PDF of the proton.
[ { "created": "Mon, 22 Nov 2004 20:34:28 GMT", "version": "v1" } ]
2010-11-05
[ [ "Kniehl", "B. A.", "" ], [ "Kramer", "G.", "" ], [ "Maniatis", "M.", "" ] ]
We calculate the cross section for the inclusive production of single hadrons with finite transverse momenta in deep-inelastic scattering at next-to-leading order (NLO), i.e. through O(alpha_s^2), in the parton model of QCD endowed with non-perturbative parton distribution functions (PDFs) and fragmentation functions (FFs). The NLO correction is found to produce a sizeable enhancement in cross section, of up to one order of magnitude, bringing the theoretical prediction to good agreement with recent measurements for neutral pions and charged hadrons at DESY HERA. This provides a useful test for the universality and the scaling violations of the FFs predicted by the factorization theorem. Such comparisons can also be used to constrain the gluon PDF of the proton.
0810.1104
Sandy S. C. Law
Xiao-Gang He, Sandy S. C. Law, Raymond R. Volkas
Determining the heavy seesaw neutrino mass matrix from low-energy parameters
19 pages, 7 figures; v2: typos corrected, new ref. added; v3:added discussion and references, this version accepted by PRD
Phys.Rev.D78:113001,2008
10.1103/PhysRevD.78.113001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with inter-family or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.
[ { "created": "Tue, 7 Oct 2008 06:56:24 GMT", "version": "v1" }, { "created": "Mon, 13 Oct 2008 01:53:46 GMT", "version": "v2" }, { "created": "Thu, 13 Nov 2008 00:13:34 GMT", "version": "v3" } ]
2010-04-15
[ [ "He", "Xiao-Gang", "" ], [ "Law", "Sandy S. C.", "" ], [ "Volkas", "Raymond R.", "" ] ]
We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family symmetries to determine the neutrino Dirac mass matrix in terms of the charged-lepton or quark mass matrices, together with inter-family or flavor symmetries to determine diagonalization matrices. Implications for leptogenesis and collider detection of heavy neutral leptons are discussed. We show that leptogenesis can succeed in small regions of parameter space for the case where the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield a heavy neutral lepton as light as about 1 TeV, but detecting such a particle will be difficult.
0912.4094
HongWei Ke
Hong-Wei Ke, Xue-Qian Li and Zheng-Tao Wei
Determining the $\eta-\eta'$ mixing by the newly measured $BR(D(D_s)\to\eta(\eta')+\bar l+\nu_l$
11 pages and 3 figures, some changes were made. Accepted by EPJC
Eur.Phys.J.C69:133-138,2010
10.1140/epjc/s10052-010-1383-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mixing of $\eta-\eta'$ or $\eta-\eta'-G$ is of a great theoretical interest, because it concerns many aspects of the underlying dynamics and hadronic structure of pseudoscalar mesons and glueball. Determining the mixing parameters by fitting data is by no means trivial. In order to extract the mixing parameters from the available processes where hadrons are involved, theoretical evaluation of hadronic matrix elements is necessary. Therefore model-dependence is somehow unavoidable. In fact, it is impossible to extract the mixing angle from a unique experiment because the model parameters must be obtained by fitting other experiments. Recently $BR(D\to\eta+\bar l+\nu_l)$ and $BR(D_s\to\eta(\eta')+\bar l+\nu_l)$ have been measured, thus we are able to determine the $\eta-\eta'$ mixing solely from the semileptonic decays of D-mesons where contamination from the final state interactions is absent. Thus we hope that the model-dependence of the extraction can be somehow alleviated. Once $BR(D\to\eta'+\bar l+\nu_l)$ is measured, we can further determine all the mixing parameters for $\eta-\eta'-G$. As more data are accumulated, the determination will be more accurate. In this work, we obtain the transition matrix elements of $D_{(s)}\to \eta^{(\prime)}$ using the light-front quark model whose feasibility and reasonability for such processes have been tested.
[ { "created": "Mon, 21 Dec 2009 08:08:14 GMT", "version": "v1" }, { "created": "Thu, 17 Jun 2010 01:30:10 GMT", "version": "v2" } ]
2011-02-09
[ [ "Ke", "Hong-Wei", "" ], [ "Li", "Xue-Qian", "" ], [ "Wei", "Zheng-Tao", "" ] ]
The mixing of $\eta-\eta'$ or $\eta-\eta'-G$ is of a great theoretical interest, because it concerns many aspects of the underlying dynamics and hadronic structure of pseudoscalar mesons and glueball. Determining the mixing parameters by fitting data is by no means trivial. In order to extract the mixing parameters from the available processes where hadrons are involved, theoretical evaluation of hadronic matrix elements is necessary. Therefore model-dependence is somehow unavoidable. In fact, it is impossible to extract the mixing angle from a unique experiment because the model parameters must be obtained by fitting other experiments. Recently $BR(D\to\eta+\bar l+\nu_l)$ and $BR(D_s\to\eta(\eta')+\bar l+\nu_l)$ have been measured, thus we are able to determine the $\eta-\eta'$ mixing solely from the semileptonic decays of D-mesons where contamination from the final state interactions is absent. Thus we hope that the model-dependence of the extraction can be somehow alleviated. Once $BR(D\to\eta'+\bar l+\nu_l)$ is measured, we can further determine all the mixing parameters for $\eta-\eta'-G$. As more data are accumulated, the determination will be more accurate. In this work, we obtain the transition matrix elements of $D_{(s)}\to \eta^{(\prime)}$ using the light-front quark model whose feasibility and reasonability for such processes have been tested.
hep-ph/0008243
Xavier Calmet
Xavier Calmet, Harald Fritzsch (Munich U.)
The Electroweak Interactions as a Confinement Phenomenon
15 pages, 1 figure, to appear in Physics Letters B
Phys.Lett. B496 (2000) 161-168
10.1016/S0370-2693(00)01299-5
LMU 10/00
hep-ph hep-th
null
We consider a model for the electroweak interactions based on the assumption that physical particles are singlets under the gauge group SU(2). The concept of complementarity explains why the standard model works with such an extraordinary precision although the fermions and bosons of the model can be viewed as composite objects of some more fundamental fermions and bosons. We study the incorporation of QED in the model. Furthermore we consider possible deviations from the standard model at very high energies, e.g. excited states of the weak bosons.
[ { "created": "Wed, 23 Aug 2000 12:25:51 GMT", "version": "v1" }, { "created": "Mon, 13 Nov 2000 10:15:32 GMT", "version": "v2" } ]
2009-10-31
[ [ "Calmet", "Xavier", "", "Munich U." ], [ "Fritzsch", "Harald", "", "Munich U." ] ]
We consider a model for the electroweak interactions based on the assumption that physical particles are singlets under the gauge group SU(2). The concept of complementarity explains why the standard model works with such an extraordinary precision although the fermions and bosons of the model can be viewed as composite objects of some more fundamental fermions and bosons. We study the incorporation of QED in the model. Furthermore we consider possible deviations from the standard model at very high energies, e.g. excited states of the weak bosons.
hep-ph/0506106
Keith Olive
Keith A. Olive, Maxim Pospelov, Adam Ritz and Yudi Santoso
CP-odd Phase Correlations and Electric Dipole Moments
31 pages, 21 eps figures; v2: additional remarks on 2-loop threshold corrections and references added; v3: typos corrected, to appear in Phys. Rev. D
Phys.Rev.D72:075001,2005
10.1103/PhysRevD.72.075001
UMN-TH-2401/05, FTPI-MINN-05/13, CERN-PH-TH-2005-095
hep-ph
null
We revisit the constraints imposed by electric dipole moments (EDMs) of nucleons and heavy atoms on new CP-violating sources within supersymmetric theories. We point out that certain two-loop renormalization group corrections induce significant mixing between the basis-invariant CP-odd phases. In the framework of the constrained minimal supersymmetric standard model (CMSSM), the CP-odd invariant related to the soft trilinear A-phase at the GUT scale, theta_A, induces non-trivial and distinct CP-odd phases for the three gaugino masses at the weak scale. The latter give one-loop contributions to EDMs enhanced by tan beta, and can provide the dominant contribution to the electron EDM induced by theta_A. We perform a detailed analysis of the EDM constraints within the CMSSM, exhibiting the reach, in terms of sparticle spectra, which may be obtained assuming generic phases, as well as the limits on the CP-odd phases for some specific parameter points where detailed phenomenological studies are available. We also illustrate how this reach will expand with results from the next generation of experiments which are currently in development.
[ { "created": "Fri, 10 Jun 2005 16:51:32 GMT", "version": "v1" }, { "created": "Thu, 30 Jun 2005 14:22:15 GMT", "version": "v2" }, { "created": "Fri, 16 Sep 2005 10:01:15 GMT", "version": "v3" } ]
2009-09-15
[ [ "Olive", "Keith A.", "" ], [ "Pospelov", "Maxim", "" ], [ "Ritz", "Adam", "" ], [ "Santoso", "Yudi", "" ] ]
We revisit the constraints imposed by electric dipole moments (EDMs) of nucleons and heavy atoms on new CP-violating sources within supersymmetric theories. We point out that certain two-loop renormalization group corrections induce significant mixing between the basis-invariant CP-odd phases. In the framework of the constrained minimal supersymmetric standard model (CMSSM), the CP-odd invariant related to the soft trilinear A-phase at the GUT scale, theta_A, induces non-trivial and distinct CP-odd phases for the three gaugino masses at the weak scale. The latter give one-loop contributions to EDMs enhanced by tan beta, and can provide the dominant contribution to the electron EDM induced by theta_A. We perform a detailed analysis of the EDM constraints within the CMSSM, exhibiting the reach, in terms of sparticle spectra, which may be obtained assuming generic phases, as well as the limits on the CP-odd phases for some specific parameter points where detailed phenomenological studies are available. We also illustrate how this reach will expand with results from the next generation of experiments which are currently in development.
hep-ph/0009216
Rahul Basu
Ramesh Anishetty and Rahul Basu (IMSc, Madras)
Dileptons from $\eta_c$ in Nucleus-Nucleus collisions
LaTeX2e, 8 pages, 5 figure files (eps), minor changes, version to appear in Phys. Lett. B
Phys.Lett. B495 (2000) 295-299
10.1016/S0370-2693(00)01248-X
IMSc-2000/09/51
hep-ph
null
Preliminary estimates suggest that excess dimuon production with invariant mass in the range 1.5 -- 2.5 GeV in nucleus-nucleus collisions can be explained on the basis of $\eta_c$ production. This appears to be consistent with all the peripheral and central collision data with various nuclei such as S-U at 200 GeV/nucleon except for the central collision data on Pb-Pb at 158 GeV/nucleon. Some explanations based on glueball production for Pb-Pb data are discussed.
[ { "created": "Tue, 19 Sep 2000 04:29:39 GMT", "version": "v1" }, { "created": "Fri, 20 Oct 2000 10:34:36 GMT", "version": "v2" } ]
2009-10-31
[ [ "Anishetty", "Ramesh", "", "IMSc, Madras" ], [ "Basu", "Rahul", "", "IMSc, Madras" ] ]
Preliminary estimates suggest that excess dimuon production with invariant mass in the range 1.5 -- 2.5 GeV in nucleus-nucleus collisions can be explained on the basis of $\eta_c$ production. This appears to be consistent with all the peripheral and central collision data with various nuclei such as S-U at 200 GeV/nucleon except for the central collision data on Pb-Pb at 158 GeV/nucleon. Some explanations based on glueball production for Pb-Pb data are discussed.
2401.04499
Carlota Andres
Carlota Andres
Jet medium modifications
Proceedings for Hard Probes 2023. 10 pages, 2 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Since the start of the heavy-ion collision programs at the Relativistic Heavy Ion Collider and the Large Hadron Collider, the study of jet modifications resulting from their interactions with the produced QCD matter has provided a unique tool to investigate and characterize the properties of the quark-gluon plasma. In this mini-overview, I will present the recent theoretical advancements in describing and understanding the modifications of jets within a QCD medium.
[ { "created": "Tue, 9 Jan 2024 11:23:16 GMT", "version": "v1" } ]
2024-01-10
[ [ "Andres", "Carlota", "" ] ]
Since the start of the heavy-ion collision programs at the Relativistic Heavy Ion Collider and the Large Hadron Collider, the study of jet modifications resulting from their interactions with the produced QCD matter has provided a unique tool to investigate and characterize the properties of the quark-gluon plasma. In this mini-overview, I will present the recent theoretical advancements in describing and understanding the modifications of jets within a QCD medium.
1511.07255
Shun Zhou
Shun Zhou
Theoretical Results on Neutrinos
15 pages, 3 figures, contribution to Lepton Photon 2015, 17-22 August, Ljubljana, Slovenia
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, I first summarize our current knowledge about the fundamental properties of neutrinos and emphasize the remaining unsolved problems in neutrino physics. Then, recent theoretical results on neutrino mass models are introduced. Different approaches to understanding tiny neutrino masses, lepton flavor mixing and CP violation are presented. Finally, I report briefly some new progress in the studies of astrophysical neutrinos, including keV sterile neutrinos, supernova neutrinos and ultrahigh-energy cosmic neutrinos.
[ { "created": "Mon, 23 Nov 2015 15:01:53 GMT", "version": "v1" } ]
2015-11-24
[ [ "Zhou", "Shun", "" ] ]
In this talk, I first summarize our current knowledge about the fundamental properties of neutrinos and emphasize the remaining unsolved problems in neutrino physics. Then, recent theoretical results on neutrino mass models are introduced. Different approaches to understanding tiny neutrino masses, lepton flavor mixing and CP violation are presented. Finally, I report briefly some new progress in the studies of astrophysical neutrinos, including keV sterile neutrinos, supernova neutrinos and ultrahigh-energy cosmic neutrinos.
hep-ph/0502137
Umberto D'Alesio
U. D'Alesio (University and INFN, Cagliari, Italy)
Hadron Spin Structure: Novel Effects from Transverse Single Spin Asymmetries
LaTeX 2e, 3 pages, 2 ps figures, uses aipproc.cls. Talk delivered at the 6th Conference on ``Quark Confinement and the Hadron Spectrum'', September 21-25, 2004, Villasimius, Italy
null
10.1063/1.1921021
null
hep-ph
null
Transverse single spin asymmetries can be a challenging tool in our understanding of the internal structure of hadrons. Some aspects and recent results are discussed.
[ { "created": "Tue, 15 Feb 2005 12:45:25 GMT", "version": "v1" } ]
2009-11-11
[ [ "D'Alesio", "U.", "", "University and INFN, Cagliari, Italy" ] ]
Transverse single spin asymmetries can be a challenging tool in our understanding of the internal structure of hadrons. Some aspects and recent results are discussed.
0710.4921
Sergey Afonin
S. S. Afonin
Weinberg like sum rules revisited
31 pages, noticed misprints are corrected, references are added, and other minor corrections are made
PMC Phys.A3:1,2009
10.1186/1754-0410-3-1
null
hep-ph
null
The generalized Weinberg sum rules containing the difference of isovector vector and axial-vector spectral functions saturated by both finite and infinite number of narrow resonances are considered. We summarize the status of these sum rules and analyze their overall agreement with phenomenological Lagrangians, low-energy relations, parity doubling, hadron string models, and experimental data.
[ { "created": "Thu, 25 Oct 2007 17:31:03 GMT", "version": "v1" }, { "created": "Mon, 29 Oct 2007 15:22:02 GMT", "version": "v2" } ]
2009-05-07
[ [ "Afonin", "S. S.", "" ] ]
The generalized Weinberg sum rules containing the difference of isovector vector and axial-vector spectral functions saturated by both finite and infinite number of narrow resonances are considered. We summarize the status of these sum rules and analyze their overall agreement with phenomenological Lagrangians, low-energy relations, parity doubling, hadron string models, and experimental data.
hep-ph/9707528
George W. S. Hou
George Wei-Shu Hou
Perspectives on Quark Mass and Mixing Relations
16 pages, latex, two eps figures (included). [NOTE ADDED: Talk presented at the Workshop on Masses and Mixings of Quarks and Leptons, University of Shizuoka, Japan, March 19 - 21, 1997]
null
null
NTUTH-97-04
hep-ph
null
Two down-up perspectives on quark mass-mixing relations are reviewed. The modified Fritzsch path relates $V_{cb}$ and $V_{ub}$ to $M_u$, but has trouble with the low $V_{cb} \simeq 0.04$ value. The modified Wolfenstein path focuses on the change in $V_{ub}$ from $\lambda^3 { (ca. 1983)} \leadsto \lambda^4 { (ca. 1994)}$. The relations $m_d/m_s\sim m_s/m_b \sim \delta \sim \lambda^2 \simeq | V_{cb}| \simeq | V_{us}|^2$ and $m_u/m_c\sim m_c/m_t \sim \delta^2 \sim \lambda^4 \sim | V_{ub}|$ suggest a clean separation of the origin of $V_{KM}$: $| V_{us}| \equiv \lambda$ and $| V_{cb}| \equiv \delta$ arise from $M_d$ while $V_{ub} \equiv B\lambda^4 e^{-i\phi}$ comes from $M_u$. Five to six parameters might suffice for ten mass-mixing parameters, with $\delta$ seemingly the more sensible expansion parameter, while $\lambda \simeq \sqrt{m_d/m_s}$ is tied empirically to $(M_d)_{11} = 0$. The approximate relations suggest a near weak scale origin of flavor.
[ { "created": "Thu, 31 Jul 1997 02:00:39 GMT", "version": "v1" }, { "created": "Sat, 2 Aug 1997 05:57:54 GMT", "version": "v2" } ]
2008-02-03
[ [ "Hou", "George Wei-Shu", "" ] ]
Two down-up perspectives on quark mass-mixing relations are reviewed. The modified Fritzsch path relates $V_{cb}$ and $V_{ub}$ to $M_u$, but has trouble with the low $V_{cb} \simeq 0.04$ value. The modified Wolfenstein path focuses on the change in $V_{ub}$ from $\lambda^3 { (ca. 1983)} \leadsto \lambda^4 { (ca. 1994)}$. The relations $m_d/m_s\sim m_s/m_b \sim \delta \sim \lambda^2 \simeq | V_{cb}| \simeq | V_{us}|^2$ and $m_u/m_c\sim m_c/m_t \sim \delta^2 \sim \lambda^4 \sim | V_{ub}|$ suggest a clean separation of the origin of $V_{KM}$: $| V_{us}| \equiv \lambda$ and $| V_{cb}| \equiv \delta$ arise from $M_d$ while $V_{ub} \equiv B\lambda^4 e^{-i\phi}$ comes from $M_u$. Five to six parameters might suffice for ten mass-mixing parameters, with $\delta$ seemingly the more sensible expansion parameter, while $\lambda \simeq \sqrt{m_d/m_s}$ is tied empirically to $(M_d)_{11} = 0$. The approximate relations suggest a near weak scale origin of flavor.
hep-ph/0604236
Mikhail Shaposhnikov
Mikhail Shaposhnikov and Igor Tkachev
The $\nu$MSM, Inflation, and Dark Matter
9 pages, misprints corrected, final version appeared in Phys. Lett
Phys.Lett.B639:414-417,2006
10.1016/j.physletb.2006.06.063
CERN-PH-TH/2006-069
hep-ph astro-ph hep-th
null
We show how to enlarge the $\nu$MSM (the minimal extension of the standard model by three right-handed neutrinos) to incorporate inflation and provide a common source for electroweak symmetry breaking and for right-handed neutrino masses. In addition to inflation, the resulting theory can explain simultaneously dark matter and the baryon asymmetry of the Universe; it is consistent with experiments on neutrino oscillations and with all astrophysical and cosmological constraints on sterile neutrino as a dark matter candidate. The mass of inflaton can be much smaller than the electroweak scale.
[ { "created": "Thu, 27 Apr 2006 19:29:15 GMT", "version": "v1" }, { "created": "Thu, 3 Aug 2006 08:50:21 GMT", "version": "v2" } ]
2011-05-05
[ [ "Shaposhnikov", "Mikhail", "" ], [ "Tkachev", "Igor", "" ] ]
We show how to enlarge the $\nu$MSM (the minimal extension of the standard model by three right-handed neutrinos) to incorporate inflation and provide a common source for electroweak symmetry breaking and for right-handed neutrino masses. In addition to inflation, the resulting theory can explain simultaneously dark matter and the baryon asymmetry of the Universe; it is consistent with experiments on neutrino oscillations and with all astrophysical and cosmological constraints on sterile neutrino as a dark matter candidate. The mass of inflaton can be much smaller than the electroweak scale.
hep-ph/0407223
Jernej Kamenik
S. Fajfer, J. Kamenik, P. Singer
New-Physics scenarios in $\Delta S = 2$ decays of the B_c meson
21 pages
Phys.Rev.D70:074022,2004
10.1103/PhysRevD.70.074022
null
hep-ph
null
The $\Delta S = 2$ transition $b \to s s \bar d$ is extremely small in the standard model, proceeding only via box diagrams. Such decays are thus an appropriate ground for searching new physics. We present a study of several two-body and three-body decays of the B_c meson belonging to this class. Our calculation covers the minimal supersymmetric model with and without R-parity and a two-Higgs-doublet model. The current limits on the parameters of these models allow for rather large branching ratios for several two and three-body hadronic decay modes of B_c, up to the 10^{-4} range in the minimal supersymmetric model with R-parity violation.
[ { "created": "Tue, 20 Jul 2004 10:03:07 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fajfer", "S.", "" ], [ "Kamenik", "J.", "" ], [ "Singer", "P.", "" ] ]
The $\Delta S = 2$ transition $b \to s s \bar d$ is extremely small in the standard model, proceeding only via box diagrams. Such decays are thus an appropriate ground for searching new physics. We present a study of several two-body and three-body decays of the B_c meson belonging to this class. Our calculation covers the minimal supersymmetric model with and without R-parity and a two-Higgs-doublet model. The current limits on the parameters of these models allow for rather large branching ratios for several two and three-body hadronic decay modes of B_c, up to the 10^{-4} range in the minimal supersymmetric model with R-parity violation.
1306.6108
Roberto Franceschini
R. Franceschini and R. N. Mohapatra
Radiatively Induced Type II seesaw and Vector-like 5/3 Charge Quarks
25 pages, 2 figures
null
10.1103/PhysRevD.89.055013
UMD-PP-013-007
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding small neutrino masses in type II seesaw models with TeV scale SM triplet Higgs bosons requires that its coupling with the standard model Higgs doublet H be dialed down to be order eV to KeV, which is a fine-tuning by a factor of $10^{-11}-10^{-8}$ with respect to the weak scale. We present a SUSY extension of the type II seesaw model where this dimensionful small coupling is radiatively induced, thus making its smallness natural. This model has an exotic vector-like quark doublet which contains a quark X with electric charge 5/3 and a top partner t'. We discuss in details the phenomenology of the model paying special attention to the consequences of the interactions of the the exotic heavy quarks and the scalars of the model. Implications for neutrinoless double beta decay and for the LHC experiments are discussed in detail. Remarkably, in this model both the seesaw triplet and the heavy quarks can manifest at colliders in a host of different signatures, including some that significantly differ from those of the minimal models. Depending on the choice of the hierarchy of couplings, the decay of the heavy quarks and of the seesaw triplet may be subject to bounds that can be tighter or looser than the bounds from standard LHC searches. Furthermore we point out a new short-distance contribution to neutrinoless double beta decay mediated by the simultaneous propagation of the type II triplet and exotic fermions. Remarkably this contribution to the neutrinoless double beta decay is parametrically quite independent from the scale of the generated neutrino mass.
[ { "created": "Wed, 26 Jun 2013 00:02:37 GMT", "version": "v1" } ]
2015-06-16
[ [ "Franceschini", "R.", "" ], [ "Mohapatra", "R. N.", "" ] ]
Understanding small neutrino masses in type II seesaw models with TeV scale SM triplet Higgs bosons requires that its coupling with the standard model Higgs doublet H be dialed down to be order eV to KeV, which is a fine-tuning by a factor of $10^{-11}-10^{-8}$ with respect to the weak scale. We present a SUSY extension of the type II seesaw model where this dimensionful small coupling is radiatively induced, thus making its smallness natural. This model has an exotic vector-like quark doublet which contains a quark X with electric charge 5/3 and a top partner t'. We discuss in details the phenomenology of the model paying special attention to the consequences of the interactions of the the exotic heavy quarks and the scalars of the model. Implications for neutrinoless double beta decay and for the LHC experiments are discussed in detail. Remarkably, in this model both the seesaw triplet and the heavy quarks can manifest at colliders in a host of different signatures, including some that significantly differ from those of the minimal models. Depending on the choice of the hierarchy of couplings, the decay of the heavy quarks and of the seesaw triplet may be subject to bounds that can be tighter or looser than the bounds from standard LHC searches. Furthermore we point out a new short-distance contribution to neutrinoless double beta decay mediated by the simultaneous propagation of the type II triplet and exotic fermions. Remarkably this contribution to the neutrinoless double beta decay is parametrically quite independent from the scale of the generated neutrino mass.
2203.11110
Joshua Isaacson
J. M. Campbell, M. Diefenthaler, T. J. Hobbs, S. H\"oche, J. Isaacson, F. Kling, S. Mrenna, J. Reuter, S. Alioli, J. R. Andersen, C. Andreopoulos, A. M. Ankowski, E. C. Aschenauer, A. Ashkenazi, M. D. Baker, J. L. Barrow, M. van Beekveld, G. Bewick, S. Bhattacharya, C. Bierlich, E. Bothmann, P. Bredt, A. Broggio, A. Buckley, A. Butter, J. M. Butterworth, E. P. Byrne, C. M. Carloni Calame, S. Chakraborty, X. Chen, M. Chiesa, J. T. Childers, J. Cruz-Martinez, J. Currie, N. Darvishi, M. Dasgupta, A. Denner, F. A. Dreyer, S. Dytman, B. K. El-Menoufi, T. Engel, S. Ferrario Ravasio, D. Figueroa, L. Flower, J. R. Forshaw, R. Frederix, A. Friedland, S. Frixione, H. Gallagher, K. Gallmeister, S. Gardiner, R. Gauld, J. Gaunt, A. Gavardi, T. Gehrmann, A. Gehrmann-De Ridder, L. Gellersen, W. Giele, S. Gieseke, F. Giuli, E. W. N. Glover, M. Grazzini, A. Grohsjean, C. G\"utschow, K. Hamilton, T. Han, R. Hatcher, G. Heinrich, I. Helenius, O. Hen, V. Hirschi, M. H\"ofer, J. Holguin, A. Huss, P. Ilten, S. Jadach, A. Jentsch, S.P. Jones, W. Ju, S. Kallweit, A. Karlberg, T. Katori, M. Kerner, W. Kilian, M. M. Kirchgae{\ss}er, S. Klein, M. Knobbe, C. Krause, F. Krauss, J. Lang, J.-N. Lang, G. Lee, S. W. Li, M. A. Lim, J. M. Lindert, D. Lombardi, L. L\"onnblad, M. L\"oschner, N. Lurkin, Y. Ma, P. Machado, V. Magerya, A. Maier, I. Majer, F. Maltoni, M. Marcoli, G. Marinelli, M. R. Masouminia, P. Mastrolia, O. Mattelaer, J. Mazzitelli, J. McFayden, R. Medves, P. Meinzinger, J. Mo, P. F. Monni, G. Montagna, T. Morgan, U. Mosel, B. Nachman, P. Nadolsky, R. Nagar, Z. Nagy, D. Napoletano, P. Nason, T. Neumann, L. J. Nevay, O. Nicrosini, J. Niehues, K. Niewczas, T. Ohl, G. Ossola, V. Pandey, A. Papadopoulou, A. Papaefstathiou, G. Paz, M. Pellen, G. Pelliccioli, T. Peraro, F. Piccinini, L. Pickering, J. Pires, W. P{\l}aczek, S. Pl\"atzer, T. Plehn, S. Pozzorini, S. Prestel, C. T. Preuss, A. C. Price, S. Quackenbush, E. Re, D. Reichelt, L. Reina, C. Reuschle, P. Richardson, M. Rocco, N. Rocco, M. Roda, A. Rodriguez Garcia, S. Roiser, J. Rojo, L. Rottoli, G. P. Salam, M. Sch\"onherr, S. Schuchmann, S. Schumann, R. Sch\"urmann, L. Scyboz, M. H. Seymour, F. Siegert, A. Signer, G. Singh Chahal, A. Si\'odmok, T. Sj\"ostrand, P. Skands, J. M. Smillie, J. T. Sobczyk, D. Soldin, D. E. Soper, A. Soto-Ontoso, G. Soyez, G. Stagnitto, J. Tena-Vidal, O. Tomalak, F. Tramontano, S. Trojanowski, Z. Tu, S. Uccirati, T. Ullrich, Y. Ulrich, M. Utheim, A. Valassi, A. Verbytskyi, R. Verheyen, M. Wagman, D. Walker, B. R. Webber, L. Weinstein, O. White, J. Whitehead, M. Wiesemann, C. Wilkinson, C. Williams, R. Winterhalder, C. Wret, K. Xie, T-Z. Yang, E. Yazgan, G. Zanderighi, S. Zanoli, and K. Zapp
Event Generators for High-Energy Physics Experiments
164 pages, 10 figures, contribution to Snowmass 2021
null
null
CP3-22-12, DESY-22-042, FERMILAB-PUB-22-116-SCD-T, IPPP/21/51, JLAB-PHY-22-3576, KA-TP-04-2022, LA-UR-22-22126, LU-TP-22-12, MCNET-22-04, OUTP-22-03P, P3H-22-024, PITT-PACC 2207, UCI-TR-2022-02
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments.
[ { "created": "Mon, 21 Mar 2022 16:40:17 GMT", "version": "v1" }, { "created": "Fri, 7 Oct 2022 15:09:56 GMT", "version": "v2" }, { "created": "Tue, 23 Jan 2024 21:49:41 GMT", "version": "v3" } ]
2024-01-25
[ [ "Campbell", "J. M.", "" ], [ "Diefenthaler", "M.", "" ], [ "Hobbs", "T. J.", "" ], [ "Höche", "S.", "" ], [ "Isaacson", "J.", "" ], [ "Kling", "F.", "" ], [ "Mrenna", "S.", "" ], [ "Reuter", "J.", "" ], [ "Alioli", "S.", "" ], [ "Andersen", "J. R.", "" ], [ "Andreopoulos", "C.", "" ], [ "Ankowski", "A. M.", "" ], [ "Aschenauer", "E. C.", "" ], [ "Ashkenazi", "A.", "" ], [ "Baker", "M. D.", "" ], [ "Barrow", "J. L.", "" ], [ "van Beekveld", "M.", "" ], [ "Bewick", "G.", "" ], [ "Bhattacharya", "S.", "" ], [ "Bierlich", "C.", "" ], [ "Bothmann", "E.", "" ], [ "Bredt", "P.", "" ], [ "Broggio", "A.", "" ], [ "Buckley", "A.", "" ], [ "Butter", "A.", "" ], [ "Butterworth", "J. M.", "" ], [ "Byrne", "E. P.", "" ], [ "Calame", "C. M. Carloni", "" ], [ "Chakraborty", "S.", "" ], [ "Chen", "X.", "" ], [ "Chiesa", "M.", "" ], [ "Childers", "J. T.", "" ], [ "Cruz-Martinez", "J.", "" ], [ "Currie", "J.", "" ], [ "Darvishi", "N.", "" ], [ "Dasgupta", "M.", "" ], [ "Denner", "A.", "" ], [ "Dreyer", "F. A.", "" ], [ "Dytman", "S.", "" ], [ "El-Menoufi", "B. K.", "" ], [ "Engel", "T.", "" ], [ "Ravasio", "S. Ferrario", "" ], [ "Figueroa", "D.", "" ], [ "Flower", "L.", "" ], [ "Forshaw", "J. R.", "" ], [ "Frederix", "R.", "" ], [ "Friedland", "A.", "" ], [ "Frixione", "S.", "" ], [ "Gallagher", "H.", "" ], [ "Gallmeister", "K.", "" ], [ "Gardiner", "S.", "" ], [ "Gauld", "R.", "" ], [ "Gaunt", "J.", "" ], [ "Gavardi", "A.", "" ], [ "Gehrmann", "T.", "" ], [ "Ridder", "A. Gehrmann-De", "" ], [ "Gellersen", "L.", "" ], [ "Giele", "W.", "" ], [ "Gieseke", "S.", "" ], [ "Giuli", "F.", "" ], [ "Glover", "E. W. N.", "" ], [ "Grazzini", "M.", "" ], [ "Grohsjean", "A.", "" ], [ "Gütschow", "C.", "" ], [ "Hamilton", "K.", "" ], [ "Han", "T.", "" ], [ "Hatcher", "R.", "" ], [ "Heinrich", "G.", "" ], [ "Helenius", "I.", "" ], [ "Hen", "O.", "" ], [ "Hirschi", "V.", "" ], [ "Höfer", "M.", "" ], [ "Holguin", "J.", "" ], [ "Huss", "A.", "" ], [ "Ilten", "P.", "" ], [ "Jadach", "S.", "" ], [ "Jentsch", "A.", "" ], [ "Jones", "S. P.", "" ], [ "Ju", "W.", "" ], [ "Kallweit", "S.", "" ], [ "Karlberg", "A.", "" ], [ "Katori", "T.", "" ], [ "Kerner", "M.", "" ], [ "Kilian", "W.", "" ], [ "Kirchgaeßer", "M. M.", "" ], [ "Klein", "S.", "" ], [ "Knobbe", "M.", "" ], [ "Krause", "C.", "" ], [ "Krauss", "F.", "" ], [ "Lang", "J.", "" ], [ "Lang", "J. -N.", "" ], [ "Lee", "G.", "" ], [ "Li", "S. W.", "" ], [ "Lim", "M. A.", "" ], [ "Lindert", "J. M.", "" ], [ "Lombardi", "D.", "" ], [ "Lönnblad", "L.", "" ], [ "Löschner", "M.", "" ], [ "Lurkin", "N.", "" ], [ "Ma", "Y.", "" ], [ "Machado", "P.", "" ], [ "Magerya", "V.", "" ], [ "Maier", "A.", "" ], [ "Majer", "I.", "" ], [ "Maltoni", "F.", "" ], [ "Marcoli", "M.", "" ], [ "Marinelli", "G.", "" ], [ "Masouminia", "M. R.", "" ], [ "Mastrolia", "P.", "" ], [ "Mattelaer", "O.", "" ], [ "Mazzitelli", "J.", "" ], [ "McFayden", "J.", "" ], [ "Medves", "R.", "" ], [ "Meinzinger", "P.", "" ], [ "Mo", "J.", "" ], [ "Monni", "P. F.", "" ], [ "Montagna", "G.", "" ], [ "Morgan", "T.", "" ], [ "Mosel", "U.", "" ], [ "Nachman", "B.", "" ], [ "Nadolsky", "P.", "" ], [ "Nagar", "R.", "" ], [ "Nagy", "Z.", "" ], [ "Napoletano", "D.", "" ], [ "Nason", "P.", "" ], [ "Neumann", "T.", "" ], [ "Nevay", "L. J.", "" ], [ "Nicrosini", "O.", "" ], [ "Niehues", "J.", "" ], [ "Niewczas", "K.", "" ], [ "Ohl", "T.", "" ], [ "Ossola", "G.", "" ], [ "Pandey", "V.", "" ], [ "Papadopoulou", "A.", "" ], [ "Papaefstathiou", "A.", "" ], [ "Paz", "G.", "" ], [ "Pellen", "M.", "" ], [ "Pelliccioli", "G.", "" ], [ "Peraro", "T.", "" ], [ "Piccinini", "F.", "" ], [ "Pickering", "L.", "" ], [ "Pires", "J.", "" ], [ "Płaczek", "W.", "" ], [ "Plätzer", "S.", "" ], [ "Plehn", "T.", "" ], [ "Pozzorini", "S.", "" ], [ "Prestel", "S.", "" ], [ "Preuss", "C. T.", "" ], [ "Price", "A. C.", "" ], [ "Quackenbush", "S.", "" ], [ "Re", "E.", "" ], [ "Reichelt", "D.", "" ], [ "Reina", "L.", "" ], [ "Reuschle", "C.", "" ], [ "Richardson", "P.", "" ], [ "Rocco", "M.", "" ], [ "Rocco", "N.", "" ], [ "Roda", "M.", "" ], [ "Garcia", "A. Rodriguez", "" ], [ "Roiser", "S.", "" ], [ "Rojo", "J.", "" ], [ "Rottoli", "L.", "" ], [ "Salam", "G. P.", "" ], [ "Schönherr", "M.", "" ], [ "Schuchmann", "S.", "" ], [ "Schumann", "S.", "" ], [ "Schürmann", "R.", "" ], [ "Scyboz", "L.", "" ], [ "Seymour", "M. H.", "" ], [ "Siegert", "F.", "" ], [ "Signer", "A.", "" ], [ "Chahal", "G. Singh", "" ], [ "Siódmok", "A.", "" ], [ "Sjöstrand", "T.", "" ], [ "Skands", "P.", "" ], [ "Smillie", "J. M.", "" ], [ "Sobczyk", "J. T.", "" ], [ "Soldin", "D.", "" ], [ "Soper", "D. E.", "" ], [ "Soto-Ontoso", "A.", "" ], [ "Soyez", "G.", "" ], [ "Stagnitto", "G.", "" ], [ "Tena-Vidal", "J.", "" ], [ "Tomalak", "O.", "" ], [ "Tramontano", "F.", "" ], [ "Trojanowski", "S.", "" ], [ "Tu", "Z.", "" ], [ "Uccirati", "S.", "" ], [ "Ullrich", "T.", "" ], [ "Ulrich", "Y.", "" ], [ "Utheim", "M.", "" ], [ "Valassi", "A.", "" ], [ "Verbytskyi", "A.", "" ], [ "Verheyen", "R.", "" ], [ "Wagman", "M.", "" ], [ "Walker", "D.", "" ], [ "Webber", "B. R.", "" ], [ "Weinstein", "L.", "" ], [ "White", "O.", "" ], [ "Whitehead", "J.", "" ], [ "Wiesemann", "M.", "" ], [ "Wilkinson", "C.", "" ], [ "Williams", "C.", "" ], [ "Winterhalder", "R.", "" ], [ "Wret", "C.", "" ], [ "Xie", "K.", "" ], [ "Yang", "T-Z.", "" ], [ "Yazgan", "E.", "" ], [ "Zanderighi", "G.", "" ], [ "Zanoli", "S.", "" ], [ "Zapp", "K.", "" ] ]
We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments.
hep-ph/9310309
Herbert Weigel
H. Weigel, R. Alkofer and H. Reinhardt
Hyperons in the Bound State Approach to the Nambu--Jona-Lasinio Chiral Soliton
40 pages, 5 figuers (not included, avaible upon request) UNITU-THEP-14/1993
Nucl.Phys.A576:477-524,1994
10.1016/0375-9474(94)90742-0
null
hep-ph
null
For the Nambu--Jona--Lasinio (NJL) model in the proper time regularization scheme the chiral soliton is investigated for the case of three flavors within the framework of the bound state approach to strangeness. For this purpose meson fluctuations off the non--strange soliton are considered. For the kaon P--wave channel the emerging Bethe--Salpeter equation is solved yielding the bound state energy and wave--function. This kaon bound state also induces a strange valence quark wave--function. Collective coordinates are introduced for the SU(2) isorotations and the coupling of the bound state to these rotations is determined. The total spin is decomposed into parts carried by the soliton and the bound state. The absolute value of the former is identical to the total isospin while the latter is demonstrated to be identical to the expectation value of the grand spin, the sum of spin and isospin. The functional trace involves quark states with various grand spins which get polarized by the kaon bound state. This polarization results in a normalization of the coupling between the collective rotation and the bound state different from the Skyrme model. Nevertheless after quantization the expression for the baryon masses can be cast into the form found by Callan and Klebanov for the Skyrme model. Numerical results for the baryon spectrum are compared to those obtained in the same model using the collective approach of Yabu and Ando. It is found that for $\frac{1}{2}^+$ baryons the bound state treatment reproduces the experimental data better than the collective approach while there are only small differences between the two approaches for the $\frac{3}{2}^+$ baryons. Both treatments underestimate the mass splittings for baryons with different strangeness. This short-coming is conjectured to be inherited from the meson sector of the NJL model where too small a ratio of the kaon and pion decay constants is predicted.
[ { "created": "Tue, 19 Oct 1993 09:44:49 GMT", "version": "v1" } ]
2009-09-25
[ [ "Weigel", "H.", "" ], [ "Alkofer", "R.", "" ], [ "Reinhardt", "H.", "" ] ]
For the Nambu--Jona--Lasinio (NJL) model in the proper time regularization scheme the chiral soliton is investigated for the case of three flavors within the framework of the bound state approach to strangeness. For this purpose meson fluctuations off the non--strange soliton are considered. For the kaon P--wave channel the emerging Bethe--Salpeter equation is solved yielding the bound state energy and wave--function. This kaon bound state also induces a strange valence quark wave--function. Collective coordinates are introduced for the SU(2) isorotations and the coupling of the bound state to these rotations is determined. The total spin is decomposed into parts carried by the soliton and the bound state. The absolute value of the former is identical to the total isospin while the latter is demonstrated to be identical to the expectation value of the grand spin, the sum of spin and isospin. The functional trace involves quark states with various grand spins which get polarized by the kaon bound state. This polarization results in a normalization of the coupling between the collective rotation and the bound state different from the Skyrme model. Nevertheless after quantization the expression for the baryon masses can be cast into the form found by Callan and Klebanov for the Skyrme model. Numerical results for the baryon spectrum are compared to those obtained in the same model using the collective approach of Yabu and Ando. It is found that for $\frac{1}{2}^+$ baryons the bound state treatment reproduces the experimental data better than the collective approach while there are only small differences between the two approaches for the $\frac{3}{2}^+$ baryons. Both treatments underestimate the mass splittings for baryons with different strangeness. This short-coming is conjectured to be inherited from the meson sector of the NJL model where too small a ratio of the kaon and pion decay constants is predicted.
hep-ph/9811204
Hans C. Eggers
H.C. Eggers, M. Greiner and P. Lipa
Analytical solution for multivariate statistics in random multiplicative cascades
Workshop on Correlations and Fluctuations, Matrahaza, June 98, uses sprocl.sty, 8 pages, 8 figs, 3 typos corrected
null
null
STPHY 29/98
hep-ph chao-dyn nlin.CD
null
It has long been a puzzle how to solve random multiplicative cascade structures analytically. We present an analytical solution found recently in the form of a simple pedagogical example of the general case.
[ { "created": "Sat, 31 Oct 1998 15:41:41 GMT", "version": "v1" }, { "created": "Fri, 20 Nov 1998 15:07:00 GMT", "version": "v2" } ]
2007-05-23
[ [ "Eggers", "H. C.", "" ], [ "Greiner", "M.", "" ], [ "Lipa", "P.", "" ] ]
It has long been a puzzle how to solve random multiplicative cascade structures analytically. We present an analytical solution found recently in the form of a simple pedagogical example of the general case.
1307.2215
Martin Schumacher
Martin Schumacher
Dispersion theory of nucleon polarizabilities and outlook on chiral effective field theory
Contribution prepared for the workshop "Compton scattering off Protons and Light Nuclei pinning down the nucleon polarizabilities" ETC* Trento Italy, July 29 . Aug. 2,2013
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on Compton scattering and meson photoproduction data the polarizabilities of the nucleon are precisely studied and well understood due to recent experimental and theoretical work based on nonsubtracted dispersion relations. The {\it recommended} experimental values are $\alpha_p=12.0\pm 0.6$, $(12.0)$, $\beta_p=1.9\mp 0.6$, $(1.9)$, $\alpha_n=12.5\pm 1.7$, $(12.7\pm 0.9)$, $\beta_n=2.7\mp 1.8$, $(2.5\mp 0.9)$ in units of $10^{-4}$fm$^3$ and $\gamma^{(p)}_\pi=-36.4\pm 1.5$, $(-36.6)$, $\gamma^{(n)}_\pi=+58.6\pm 4.0$, $(58.3)$, $(\gamma^{(p)}_0=-0.58\pm 0.20)$, $\gamma^{(n)}_0=0.38\pm 0.22)$ in units of $10^{-4}$fm$^4$ [1]. The numbers given in parentheses are predicted values. It is shown that all versions of chiral effective field theories applied in analyses of nucleon polarizabilities and Compton scattering ignore essential effects of $\omega$, $\rho$ and $\sigma$ exchanges and of pseudoscalar $\pi$N coupling.
[ { "created": "Mon, 8 Jul 2013 19:41:49 GMT", "version": "v1" }, { "created": "Thu, 10 Jul 2014 09:02:58 GMT", "version": "v2" } ]
2014-08-01
[ [ "Schumacher", "Martin", "" ] ]
Based on Compton scattering and meson photoproduction data the polarizabilities of the nucleon are precisely studied and well understood due to recent experimental and theoretical work based on nonsubtracted dispersion relations. The {\it recommended} experimental values are $\alpha_p=12.0\pm 0.6$, $(12.0)$, $\beta_p=1.9\mp 0.6$, $(1.9)$, $\alpha_n=12.5\pm 1.7$, $(12.7\pm 0.9)$, $\beta_n=2.7\mp 1.8$, $(2.5\mp 0.9)$ in units of $10^{-4}$fm$^3$ and $\gamma^{(p)}_\pi=-36.4\pm 1.5$, $(-36.6)$, $\gamma^{(n)}_\pi=+58.6\pm 4.0$, $(58.3)$, $(\gamma^{(p)}_0=-0.58\pm 0.20)$, $\gamma^{(n)}_0=0.38\pm 0.22)$ in units of $10^{-4}$fm$^4$ [1]. The numbers given in parentheses are predicted values. It is shown that all versions of chiral effective field theories applied in analyses of nucleon polarizabilities and Compton scattering ignore essential effects of $\omega$, $\rho$ and $\sigma$ exchanges and of pseudoscalar $\pi$N coupling.
1705.09781
Hidekazu Tanaka
Hidekazu Tanaka and Shuji Sasagawa
Quark mass function in Minkowski space
9 pages, 3 figures
Prog Theor Exp Phys (2017)
10.1093/ptep/ptx153
RUP-17-9
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the properties of quark mass functions in quantum chromodynamics calculated by the Schwinger-Dyson equation in the strong coupling region, in which the loop integration is performed in Minkowski space. The calculated results are compared with those obtained by integration in Euclidean space.
[ { "created": "Sat, 27 May 2017 07:35:12 GMT", "version": "v1" } ]
2019-12-06
[ [ "Tanaka", "Hidekazu", "" ], [ "Sasagawa", "Shuji", "" ] ]
We investigate the properties of quark mass functions in quantum chromodynamics calculated by the Schwinger-Dyson equation in the strong coupling region, in which the loop integration is performed in Minkowski space. The calculated results are compared with those obtained by integration in Euclidean space.
hep-ph/9707223
Michelangelo Mangano
A. Petrelli, M. Cacciari, M. Greco, F. Maltoni, M.L. Mangano
NLO Production and Decay of Quarkonium
65 pages, Latex, epsfig, 8 figures. Typos corrected and improvements made to the text. Version to appear on Nucl Phys. B
Nucl.Phys.B514:245-309,1998
10.1016/S0550-3213(97)00801-8
CERN-TH/97-142, DESY 97-090
hep-ph
null
We present a calculation of next-to-leading-order (NLO) QCD corrections to total hadronic production cross sections and to light-hadron-decay rates of heavy quarkonium states. Both colour-singlet and colour-octet contributions are included. We discuss in detail the use of covariant projectors in dimensional regularization, the structure of soft-gluon emission and the overall finiteness of radiative corrections. We compare our approach with the NLO version of the threshold-expansion technique recently introduced by Braaten and Chen. Most of the results presented here are new. Others represent the first independent reevaluation of calculations already known in the literature. In this case a comparison with previous findings is reported.
[ { "created": "Wed, 2 Jul 1997 16:20:47 GMT", "version": "v1" }, { "created": "Thu, 6 Nov 1997 12:48:42 GMT", "version": "v2" } ]
2014-11-17
[ [ "Petrelli", "A.", "" ], [ "Cacciari", "M.", "" ], [ "Greco", "M.", "" ], [ "Maltoni", "F.", "" ], [ "Mangano", "M. L.", "" ] ]
We present a calculation of next-to-leading-order (NLO) QCD corrections to total hadronic production cross sections and to light-hadron-decay rates of heavy quarkonium states. Both colour-singlet and colour-octet contributions are included. We discuss in detail the use of covariant projectors in dimensional regularization, the structure of soft-gluon emission and the overall finiteness of radiative corrections. We compare our approach with the NLO version of the threshold-expansion technique recently introduced by Braaten and Chen. Most of the results presented here are new. Others represent the first independent reevaluation of calculations already known in the literature. In this case a comparison with previous findings is reported.
hep-ph/0004107
Dr. Otto C. W. Kong
Otto C.W. Kong (Institute of Physics, Taiwan)
LR Scalar Mixings and One-loop Neutrino Masses
19 pages in JHEP style, with 8 figures incoporated; modified with extended discussion and a new appendix. Version to be published in JHEP
JHEP 0009:037,2000
10.1088/1126-6708/2000/09/037
null
hep-ph
null
Within the framework of the complete theory of supersymmetry without R-parity, where all possible R-parity violating terms are admitted, we perform a systematic analytical study of all sources of neutrino masses up to ``direct one-loop" (defined explicitly below) level. In the passing, we present the full result for squark and slepton masses. In particular, there are interesting $LR$ squark and slepton mixings, which involve both bilinear and trilinear R-parity violating parameters. The existence and important phenomenological implications of such terms have been largely overlooked in previous studies. In particular, in the studies under which either one type of the couplings is assumed to vanish or neglected, the terms would not show up. The $LR$ mixings play a central role in neutrino mass generation. Our results look straight forward to be obtained, which, in our opinion, is an illustration of the effectiveness of our formulation adopted.
[ { "created": "Wed, 12 Apr 2000 09:09:05 GMT", "version": "v1" }, { "created": "Thu, 13 Apr 2000 12:27:53 GMT", "version": "v2" }, { "created": "Fri, 30 Jun 2000 10:03:07 GMT", "version": "v3" }, { "created": "Thu, 19 Oct 2000 21:42:31 GMT", "version": "v4" } ]
2014-11-17
[ [ "Kong", "Otto C. W.", "", "Institute of Physics, Taiwan" ] ]
Within the framework of the complete theory of supersymmetry without R-parity, where all possible R-parity violating terms are admitted, we perform a systematic analytical study of all sources of neutrino masses up to ``direct one-loop" (defined explicitly below) level. In the passing, we present the full result for squark and slepton masses. In particular, there are interesting $LR$ squark and slepton mixings, which involve both bilinear and trilinear R-parity violating parameters. The existence and important phenomenological implications of such terms have been largely overlooked in previous studies. In particular, in the studies under which either one type of the couplings is assumed to vanish or neglected, the terms would not show up. The $LR$ mixings play a central role in neutrino mass generation. Our results look straight forward to be obtained, which, in our opinion, is an illustration of the effectiveness of our formulation adopted.
2207.03144
Yucheng Qiu
Yu-Cheng Qiu and S. -H. Henry Tye
A Novel Solution to the Gravitino Problem
This revised version explains some points that are confusing in the earlier version. The current version is the same as the published version. 23 pages, 1 figure, 2 tables
null
10.1007/JHEP02(2023)006
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a general phenomenological model with local supersymmetry, the amount of massive gravitinos produced in early universe tends to violate the known dark matter density bound by many orders of magnitude. In the brane world scenario in Type IIB string theory, we propose a novel way to evade this problem. There, the standard model of strong and electroweak interactions live inside the anti-${\rm D3}$-branes ($\overline{\rm D3}$-branes) that span the 3 large spatial dimensions. Here, the "potential" Goldstino to be absorbed by the gravitino (to become massive) is the fermion component of the open string nilpotent superfield $X$ (i.e., $X^2=0$) which is present only inside the $\overline{\rm D3}$-branes. This non-linear supergravity scenario offers 2 ways to solve the gravitino problem, with very different particle physics phenomenologies.
[ { "created": "Thu, 7 Jul 2022 08:06:46 GMT", "version": "v1" }, { "created": "Fri, 15 Jul 2022 10:55:14 GMT", "version": "v2" }, { "created": "Mon, 10 Oct 2022 15:08:24 GMT", "version": "v3" }, { "created": "Tue, 7 Feb 2023 05:35:03 GMT", "version": "v4" } ]
2023-02-08
[ [ "Qiu", "Yu-Cheng", "" ], [ "Tye", "S. -H. Henry", "" ] ]
In a general phenomenological model with local supersymmetry, the amount of massive gravitinos produced in early universe tends to violate the known dark matter density bound by many orders of magnitude. In the brane world scenario in Type IIB string theory, we propose a novel way to evade this problem. There, the standard model of strong and electroweak interactions live inside the anti-${\rm D3}$-branes ($\overline{\rm D3}$-branes) that span the 3 large spatial dimensions. Here, the "potential" Goldstino to be absorbed by the gravitino (to become massive) is the fermion component of the open string nilpotent superfield $X$ (i.e., $X^2=0$) which is present only inside the $\overline{\rm D3}$-branes. This non-linear supergravity scenario offers 2 ways to solve the gravitino problem, with very different particle physics phenomenologies.
hep-ph/9803328
D. Delepine
J.-M.Gerard, J.Pestieau, J.Weyers
Hadronic Phases and Isospin Amplitudes in $D(B) \to \pi \pi$ and $D(B) \to K \bar K$ Decays
10pages,latex
Phys.Lett. B436 (1998) 363-368
10.1016/S0370-2693(98)00855-7
UCL-IPT-98-04
hep-ph
null
Hadronic phase in $\pi \pi$ and $K \bar K$ channels are calculated a la Regge. At the D mass one finds $\delta_{\pi \pi} \approx \pi/3$ and $\delta_{K \bar K} \approx -\pi/6$ in good agreement with the CLEO data while at the B mass these angles are predicted to be, respectively, $11^\circ$ and $-7^\circ$. With the hadronic phase $e^{i \delta_{K \bar K}}$ taken into account, a quark diagram decomposition of the isospin invariant amplitudes in $D \to K \bar K$ decays fits the data provided the exchange diagram contribution is about 1/3 of the tree level one.
[ { "created": "Thu, 12 Mar 1998 17:12:27 GMT", "version": "v1" } ]
2009-10-31
[ [ "Gerard", "J. -M.", "" ], [ "Pestieau", "J.", "" ], [ "Weyers", "J.", "" ] ]
Hadronic phase in $\pi \pi$ and $K \bar K$ channels are calculated a la Regge. At the D mass one finds $\delta_{\pi \pi} \approx \pi/3$ and $\delta_{K \bar K} \approx -\pi/6$ in good agreement with the CLEO data while at the B mass these angles are predicted to be, respectively, $11^\circ$ and $-7^\circ$. With the hadronic phase $e^{i \delta_{K \bar K}}$ taken into account, a quark diagram decomposition of the isospin invariant amplitudes in $D \to K \bar K$ decays fits the data provided the exchange diagram contribution is about 1/3 of the tree level one.
hep-ph/9806204
Thomas Hambye
T. Hambye (Dortmund U.)
New Analysis of the Delta I = 1/2 Rule in the 1/N_c Expansion for K --> pi pi Decays
10 pages, 4 eps figures. Talk presented at the XXIth School of Theoretical Physics "Recent Progress in Theory and Phenomenology of Fundamental Interactions", Ustro\'n, Poland, September 19-24, 1997. Two typos in Eq. (17) and Eq. (18) have been corrected
Acta Phys.Polon.B28:2479,1997
null
DO-TH 98/09
hep-ph
null
We analyze long-distance contributions to the K --> pi pi amplitudes relevant for the Delta I = 1/2 selection rule in the framework of the 1/N_c expansion. We use a modified prescription for the identification of meson momenta in the chiral loop corrections to gain a consistent matching with the short-distance part. Our approach involves a separation of non-factorizable and factorizable 1/N_c corrections. Along these lines we calculate the one-loop contributions from the lowest order lagrangian. Our main result is an additional enhancement of the Delta I = 1/2 channel amplitude which we find in good agreement with experiment.
[ { "created": "Sat, 30 May 1998 17:43:11 GMT", "version": "v1" } ]
2011-03-17
[ [ "Hambye", "T.", "", "Dortmund U." ] ]
We analyze long-distance contributions to the K --> pi pi amplitudes relevant for the Delta I = 1/2 selection rule in the framework of the 1/N_c expansion. We use a modified prescription for the identification of meson momenta in the chiral loop corrections to gain a consistent matching with the short-distance part. Our approach involves a separation of non-factorizable and factorizable 1/N_c corrections. Along these lines we calculate the one-loop contributions from the lowest order lagrangian. Our main result is an additional enhancement of the Delta I = 1/2 channel amplitude which we find in good agreement with experiment.
hep-ph/0412344
Shaaban Khalil
S. Abel and S. Khalil
EDM constraints and CP asymmetries of B processes in supersymmetric models
11 pages, 2 figures
Phys.Lett.B618:201-208,2005
10.1016/j.physletb.2005.04.077
IPPP/04/87, DCPT/04/174
hep-ph
null
We demonstrate that electric dipole moments (EDMs) strongly constrain possible SUSY contributions to the CP asymmetries of B processes; LL and/or RR flavour mixings between second and third generations are severely restricted by the experimental limit on the mercury EDM, and so therefore are their possible contributions to the CP asymmetries of B --> \phi K and B --> \eta' K. We find that SUSY models with dominant LR and RL mixing through non-universal A-terms is the only way to accommodate the apparent deviation of CP asymmetries from those expected in the Standard Model without conflicting with the EDM bounds or with any other experimental results.
[ { "created": "Wed, 22 Dec 2004 15:51:02 GMT", "version": "v1" } ]
2014-11-18
[ [ "Abel", "S.", "" ], [ "Khalil", "S.", "" ] ]
We demonstrate that electric dipole moments (EDMs) strongly constrain possible SUSY contributions to the CP asymmetries of B processes; LL and/or RR flavour mixings between second and third generations are severely restricted by the experimental limit on the mercury EDM, and so therefore are their possible contributions to the CP asymmetries of B --> \phi K and B --> \eta' K. We find that SUSY models with dominant LR and RL mixing through non-universal A-terms is the only way to accommodate the apparent deviation of CP asymmetries from those expected in the Standard Model without conflicting with the EDM bounds or with any other experimental results.
2201.06664
Hiromasa Takaura
Yu Hamada, Ryuichiro Kitano, Ryutaro Matsudo, Hiromasa Takaura, Mitsuhiro Yoshida
$\mu$TRISTAN
23 pages, 7 figures, version to appear in PTEP
Prog Theor Exp Phys (2022)
10.1093/ptep/ptac059
KEK-TH-2385
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
The ultra-cold muon technology developed for the muon $g-2$ experiment at J-PARC provides a low emittance $\mu^+$ beam which can be accelerated and used for realistic collider experiments. We consider the possibility of new collider experiments by accelerating the $\mu^+$ beam up to 1 TeV. Allowing the $\mu^+$ beam to collide with a high intensity $e^-$ beam at the TRISTAN energy, $E_{e^-}= 30$ GeV, in the storage ring with the same size as TRISTAN (the circumference of 3 km), one can realize a collider experiment with the center-of-mass energy $\sqrt s = 346$ GeV, which allows productions of the Higgs bosons through the vector boson fusion processes. We estimate the deliverable luminosity with existing accelerator technologies to be at the level of $5 \times 10^{33}$ cm$^{-2}$ s$^{-1}$, with which the collider can be a good Higgs boson factory. The $\mu^+ \mu^+$ colliders up to $\sqrt s = 2$ TeV are also possible by using the same storage ring. They have a capability of producing the superpartner of the muon up to TeV masses.
[ { "created": "Mon, 17 Jan 2022 23:26:36 GMT", "version": "v1" }, { "created": "Thu, 21 Apr 2022 05:15:31 GMT", "version": "v2" } ]
2022-05-11
[ [ "Hamada", "Yu", "" ], [ "Kitano", "Ryuichiro", "" ], [ "Matsudo", "Ryutaro", "" ], [ "Takaura", "Hiromasa", "" ], [ "Yoshida", "Mitsuhiro", "" ] ]
The ultra-cold muon technology developed for the muon $g-2$ experiment at J-PARC provides a low emittance $\mu^+$ beam which can be accelerated and used for realistic collider experiments. We consider the possibility of new collider experiments by accelerating the $\mu^+$ beam up to 1 TeV. Allowing the $\mu^+$ beam to collide with a high intensity $e^-$ beam at the TRISTAN energy, $E_{e^-}= 30$ GeV, in the storage ring with the same size as TRISTAN (the circumference of 3 km), one can realize a collider experiment with the center-of-mass energy $\sqrt s = 346$ GeV, which allows productions of the Higgs bosons through the vector boson fusion processes. We estimate the deliverable luminosity with existing accelerator technologies to be at the level of $5 \times 10^{33}$ cm$^{-2}$ s$^{-1}$, with which the collider can be a good Higgs boson factory. The $\mu^+ \mu^+$ colliders up to $\sqrt s = 2$ TeV are also possible by using the same storage ring. They have a capability of producing the superpartner of the muon up to TeV masses.
hep-ph/9910486
Alexander Pankov
A.A. Pankov (Gomel Tech.U. & INFN Trieste)
Prospects on Compositeness and New Vector Bosons at LC with Polarization
9 pages with 3 figures, Presented at the International Workshop QFTHEP'99, Moscow, May 27 - June 2, 1999
null
null
null
hep-ph
null
Fermion compositness, and other new physics which can be described by an exchange of very massive particles ($Z^\prime$ boson, leptoquarks, sparticles with R-parity violating couplings), can be manifest itself as the presence of a strong four-fermion contact interaction. For the processes $e^+e^-\to \mu^+\mu^-$, $\tau^+\tau^-$, $\bar{b}b$ and $\bar{c}c$ at a future $e^+e^-$ linear collider (LC) with $\sqrt{s}=0.5$ TeV, we examine the sensitivity of the helicity cross sections to four-fermion contact interactions. If longitudinal polarization of the electron beam were available, two polarized integrated cross sections would offer the opportunity to separate the helicity cross sections and, in this way, to derive model-independent bounds on the relevant parameters. The measurement of these polarized cross sections with optimal kinematical cuts could significantly increase the sensitivity of helicity cross sections to contact interaction parameters and could give crucial information on the chiral structure of such new interactions. In addition, we consider the application of the proposed approach to the search for manifestations of a $Z^\prime$ for typical extended model examples.
[ { "created": "Tue, 26 Oct 1999 12:09:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pankov", "A. A.", "", "Gomel Tech.U. & INFN Trieste" ] ]
Fermion compositness, and other new physics which can be described by an exchange of very massive particles ($Z^\prime$ boson, leptoquarks, sparticles with R-parity violating couplings), can be manifest itself as the presence of a strong four-fermion contact interaction. For the processes $e^+e^-\to \mu^+\mu^-$, $\tau^+\tau^-$, $\bar{b}b$ and $\bar{c}c$ at a future $e^+e^-$ linear collider (LC) with $\sqrt{s}=0.5$ TeV, we examine the sensitivity of the helicity cross sections to four-fermion contact interactions. If longitudinal polarization of the electron beam were available, two polarized integrated cross sections would offer the opportunity to separate the helicity cross sections and, in this way, to derive model-independent bounds on the relevant parameters. The measurement of these polarized cross sections with optimal kinematical cuts could significantly increase the sensitivity of helicity cross sections to contact interaction parameters and could give crucial information on the chiral structure of such new interactions. In addition, we consider the application of the proposed approach to the search for manifestations of a $Z^\prime$ for typical extended model examples.
1401.1806
Mauricio Martinez
Mauricio Martinez
Coherence effects between the initial and final state radiation in a dense QCD medium
8 pages, 1 figure. Plenary contribution to the IS2013 Conference, September 8-14 2013, Illa da Toxa - Galicia (Spain). Matched with the published version
Nucl.Phys.A926:242-249,2014
10.1016/j.nuclphysa.2014.06.006
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings contribution we review our recent results of medium modifications to the coherence pattern between the initial and final state radiation. We study single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. Multiple scatterings lead to a partial suppression of the interferences between different emitters that opens the phase space for large angle emissions. We briefly discuss the generalization of this setup to describe gluon production in the case of pA collisions by including finite length and energy corrections. The configuration studied here may have phenomenological consequences in high-energy nuclear collisions.
[ { "created": "Wed, 8 Jan 2014 20:46:36 GMT", "version": "v1" }, { "created": "Thu, 26 Jun 2014 19:06:19 GMT", "version": "v2" } ]
2014-08-26
[ [ "Martinez", "Mauricio", "" ] ]
In these proceedings contribution we review our recent results of medium modifications to the coherence pattern between the initial and final state radiation. We study single gluon production off a highly energetic parton that undergoes a hard scattering and subsequently crosses a dense QCD medium of finite size. Multiple scatterings lead to a partial suppression of the interferences between different emitters that opens the phase space for large angle emissions. We briefly discuss the generalization of this setup to describe gluon production in the case of pA collisions by including finite length and energy corrections. The configuration studied here may have phenomenological consequences in high-energy nuclear collisions.
hep-ph/0601228
Christophe Royon
C. Royon
Recent results from the Tevatron
Proceedinds of the Zakopane summer school
Acta Phys.Polon.B36:3697-3722,2005
null
null
hep-ph
null
In these lectures, we describe some recent results from the D{\O}and CDF experiments at the Tevatron.
[ { "created": "Fri, 27 Jan 2006 11:03:27 GMT", "version": "v1" } ]
2010-04-22
[ [ "Royon", "C.", "" ] ]
In these lectures, we describe some recent results from the D{\O}and CDF experiments at the Tevatron.
1503.07052
Werner Vogelsang
Felix Ringer, Werner Vogelsang
Single-Spin Asymmetries in W Boson Production at Next-to-Leading Order
13 pages, 6 figures. Updated figure for comparison to RHIC data. Version to appear in Phys. Rev. D
Phys. Rev. D 91, 094033 (2015)
10.1103/PhysRevD.91.094033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an analytic next-to-leading order QCD calculation of the partonic cross sections for single-inclusive lepton production in hadronic collisions, when the lepton originates from the decay of an intermediate electroweak boson and is produced at high transverse momentum. In particular, we consider the case of incoming longitudinally polarized protons for which parity-violating single-spin asymmetries arise that are exploited in the $W$ boson program at RHIC to constrain the proton's helicity parton distributions. Our calculation enables a very fast and efficient numerical computation of the relevant spin asymmetries at RHIC, which is an important ingredient for the inclusion of RHIC data in a global analysis of nucleon helicity structure. We confirm the validity of our calculation by comparing with an existing code that treats the next-to-leading order cross sections entirely numerically by Monte-Carlo integration techniques. We also provide new comparisons of the present RHIC data with results for some of the sets of polarized parton distributions available in the literature.
[ { "created": "Tue, 24 Mar 2015 14:14:38 GMT", "version": "v1" }, { "created": "Fri, 22 May 2015 15:36:24 GMT", "version": "v2" } ]
2015-06-03
[ [ "Ringer", "Felix", "" ], [ "Vogelsang", "Werner", "" ] ]
We present an analytic next-to-leading order QCD calculation of the partonic cross sections for single-inclusive lepton production in hadronic collisions, when the lepton originates from the decay of an intermediate electroweak boson and is produced at high transverse momentum. In particular, we consider the case of incoming longitudinally polarized protons for which parity-violating single-spin asymmetries arise that are exploited in the $W$ boson program at RHIC to constrain the proton's helicity parton distributions. Our calculation enables a very fast and efficient numerical computation of the relevant spin asymmetries at RHIC, which is an important ingredient for the inclusion of RHIC data in a global analysis of nucleon helicity structure. We confirm the validity of our calculation by comparing with an existing code that treats the next-to-leading order cross sections entirely numerically by Monte-Carlo integration techniques. We also provide new comparisons of the present RHIC data with results for some of the sets of polarized parton distributions available in the literature.
1509.06748
Andrew J Powell
Joseph P. Conlon, M. C. David Marsh, Andrew J. Powell
Galaxy Cluster Thermal X-Ray Spectra Constrain Axion-Like Particles
5 pages
Phys. Rev. D 93, 123526 (2016)
10.1103/PhysRevD.93.123526
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axion-like particles (ALPs) and photons inter-convert in the presence of a magnetic field. At keV energies in the environment of galaxy clusters, the conversion probability can become unsuppressed for light ALPs. Conversion of thermal X-ray photons into ALPs can introduce a step-like feature into the cluster thermal bremsstrahlung spectrum, and we argue that existing X-ray data on galaxy clusters should be sufficient to extend bounds on ALPs in the low-mass region $m_a \lesssim 1 \times 10^{-12}\,{\rm eV}$ down to $M \sim 7\times 10^{11}\, {\rm GeV}$, and that for $10^{11}\, {\rm GeV} < M \lesssim 10^{12}$ GeV light ALPs give rise to interesting and unique observational signatures that may be probed by existing and upcoming X-ray (and potentially X-ray polarisation) observations of galaxy clusters.
[ { "created": "Tue, 22 Sep 2015 20:14:16 GMT", "version": "v1" } ]
2016-07-06
[ [ "Conlon", "Joseph P.", "" ], [ "Marsh", "M. C. David", "" ], [ "Powell", "Andrew J.", "" ] ]
Axion-like particles (ALPs) and photons inter-convert in the presence of a magnetic field. At keV energies in the environment of galaxy clusters, the conversion probability can become unsuppressed for light ALPs. Conversion of thermal X-ray photons into ALPs can introduce a step-like feature into the cluster thermal bremsstrahlung spectrum, and we argue that existing X-ray data on galaxy clusters should be sufficient to extend bounds on ALPs in the low-mass region $m_a \lesssim 1 \times 10^{-12}\,{\rm eV}$ down to $M \sim 7\times 10^{11}\, {\rm GeV}$, and that for $10^{11}\, {\rm GeV} < M \lesssim 10^{12}$ GeV light ALPs give rise to interesting and unique observational signatures that may be probed by existing and upcoming X-ray (and potentially X-ray polarisation) observations of galaxy clusters.
hep-ph/0006040
Masaki Yasue
Teruyuki Kitabayashi and Masaki Yasue
Two-loop Radiative Neutrino Mechanism in an $SU(3)_L\times U(1)_N$ Gauge Model
with 10 pages, revtex, including 2 figures, accepted for publication in Phys. Rev. D (with undefined latex citation indices removed)
null
10.1103/PhysRevD.63.095006
TOKAI-HEP/TH-0002
hep-ph
null
By using the $L_e$ - $L_\mu$ - $L_\tau$ symmetry, we construct an $SU(3)_L\times U(1)_N$ gauge model that provides two-loop radiative neutrino masses as well as one-loop radiative neutrino masses. The generic smallness of two-loop neutrino masses leading to $\Delta m^2_\odot$ compared with one-loop neutrino masses leading to $\Delta m^2_{atm}$ successfully explains $\Delta m^2_{atm}$ $>>$ $\Delta m^2_{\odot}$ by invoking the $L_e$ - $L_\mu$ - $L_\tau$ breaking. The Higgs scalar ($h^+$) that initiates radiative mechanisms is unified into a Higgs triplet together with the standard Higgs scalar ($\phi^+$, $\phi^0$) to form ($\phi^+$, $\phi^0$, $h^+$), which calls for three families of lepton triplets: ($\nu^i_L$, $\ell^i_L$, $\omega^i_L$) (i = 1,2,3), where $\omega^i$ denote heavy neutral leptons. The two-loop radiative mechanism is found possible by introducing a singly charged scalar, which couples to $\ell^i_R\omega^j_R$ (i,j = 2,3).
[ { "created": "Sun, 4 Jun 2000 15:33:23 GMT", "version": "v1" }, { "created": "Thu, 18 Jan 2001 16:22:16 GMT", "version": "v2" }, { "created": "Tue, 23 Jan 2001 03:22:54 GMT", "version": "v3" } ]
2009-10-31
[ [ "Kitabayashi", "Teruyuki", "" ], [ "Yasue", "Masaki", "" ] ]
By using the $L_e$ - $L_\mu$ - $L_\tau$ symmetry, we construct an $SU(3)_L\times U(1)_N$ gauge model that provides two-loop radiative neutrino masses as well as one-loop radiative neutrino masses. The generic smallness of two-loop neutrino masses leading to $\Delta m^2_\odot$ compared with one-loop neutrino masses leading to $\Delta m^2_{atm}$ successfully explains $\Delta m^2_{atm}$ $>>$ $\Delta m^2_{\odot}$ by invoking the $L_e$ - $L_\mu$ - $L_\tau$ breaking. The Higgs scalar ($h^+$) that initiates radiative mechanisms is unified into a Higgs triplet together with the standard Higgs scalar ($\phi^+$, $\phi^0$) to form ($\phi^+$, $\phi^0$, $h^+$), which calls for three families of lepton triplets: ($\nu^i_L$, $\ell^i_L$, $\omega^i_L$) (i = 1,2,3), where $\omega^i$ denote heavy neutral leptons. The two-loop radiative mechanism is found possible by introducing a singly charged scalar, which couples to $\ell^i_R\omega^j_R$ (i,j = 2,3).
hep-ph/0606255
Fizuli A. Mamedov
Fizuli Mamedov
Particle interactions, masses and the symmetry breaking
5 Pages
null
null
null
hep-ph
null
A possible original $SU(2)_{L} \times SU(2)_{R}$ symmetry of the elementary particles and the mechanism of its breaking is discussed. It is concluded that it is the broken symmetry states of the particles which induce the interactions among the particles.
[ { "created": "Sat, 24 Jun 2006 00:02:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mamedov", "Fizuli", "" ] ]
A possible original $SU(2)_{L} \times SU(2)_{R}$ symmetry of the elementary particles and the mechanism of its breaking is discussed. It is concluded that it is the broken symmetry states of the particles which induce the interactions among the particles.
2011.07617
Blessed Ngwenya
B. A. Ngwenya and W. A. Horowitz
B-meson Nuclear Modification Factor and $\mathbf{v_2(p_T)}$ in a Strongly Coupled Plasma in $\mathbf{Pb+Pb}$ Collisions at $\mathbf{\sqrt{s_{NN}}=2.76}$ TeV and $\mathbf{\sqrt{s_{NN}}=5.5}$ TeV
11 pages, 14 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present predictions for the suppression of B-mesons using AdS/CFT techniques assuming a strongly coupled quark-gluon plasma at $\sqrt{s_{NN}}=2.76$ TeV for central collisions and $\sqrt{s_{NN}}=5.5$ TeV for various centrality classes. We provide estimates of the systematic theoretical uncertainties due to 1) the mapping of QCD parameters to those in $\mathcal N = 4$ SYM and 2) the exact form of the momentum dependence of the diffusion coefficient predicted by AdS/CFT. We show that coupling energy loss to flow increases $v_2$ substantially out to surprisingly large momenta, on the order of $\sim 25$ GeV/c, thus pointing to a possible resolution of the $R_{AA}$ and $v_2$ puzzle for light hadrons.
[ { "created": "Sun, 15 Nov 2020 20:00:19 GMT", "version": "v1" } ]
2020-11-17
[ [ "Ngwenya", "B. A.", "" ], [ "Horowitz", "W. A.", "" ] ]
We present predictions for the suppression of B-mesons using AdS/CFT techniques assuming a strongly coupled quark-gluon plasma at $\sqrt{s_{NN}}=2.76$ TeV for central collisions and $\sqrt{s_{NN}}=5.5$ TeV for various centrality classes. We provide estimates of the systematic theoretical uncertainties due to 1) the mapping of QCD parameters to those in $\mathcal N = 4$ SYM and 2) the exact form of the momentum dependence of the diffusion coefficient predicted by AdS/CFT. We show that coupling energy loss to flow increases $v_2$ substantially out to surprisingly large momenta, on the order of $\sim 25$ GeV/c, thus pointing to a possible resolution of the $R_{AA}$ and $v_2$ puzzle for light hadrons.
1012.0267
Carlo Giunti Dr.
Carlo Giunti, Marco Laveder
Large Short-Baseline antinu_mu Disappearance
6 pages; final version published in Phys.Rev.D 83 (2011) 053006
Phys.Rev.D83:053006,2011
10.1103/PhysRevD.83.053006
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the LSND, KARMEN and MiniBooNE data on short-baseline antinu_mu -> antinu_e oscillations and the data on short-baseline antinu_e disappearance obtained in the Bugey-3 and CHOOZ reactor experiments in the framework of 3+1 antineutrino mixing, taking into account the MINOS observation of long-baseline antinu_mu disappearance and the KamLAND observation of very-long-baseline antinu_e disappearance. We show that the fit of the data implies that the short-baseline disappearance of antinu_mu is relatively large. We obtain a prediction of an effective amplitude sin^2 2 theta_{mu mu} >~ 0.1 for short-baseline antinu_mu disappearance generated by 0.2 <~ Delta m^2 <~ 1 eV^2, which could be measured in future experiments.
[ { "created": "Wed, 1 Dec 2010 18:20:58 GMT", "version": "v1" }, { "created": "Mon, 14 Feb 2011 12:05:37 GMT", "version": "v2" }, { "created": "Fri, 25 Mar 2011 16:19:00 GMT", "version": "v3" } ]
2011-03-28
[ [ "Giunti", "Carlo", "" ], [ "Laveder", "Marco", "" ] ]
We analyze the LSND, KARMEN and MiniBooNE data on short-baseline antinu_mu -> antinu_e oscillations and the data on short-baseline antinu_e disappearance obtained in the Bugey-3 and CHOOZ reactor experiments in the framework of 3+1 antineutrino mixing, taking into account the MINOS observation of long-baseline antinu_mu disappearance and the KamLAND observation of very-long-baseline antinu_e disappearance. We show that the fit of the data implies that the short-baseline disappearance of antinu_mu is relatively large. We obtain a prediction of an effective amplitude sin^2 2 theta_{mu mu} >~ 0.1 for short-baseline antinu_mu disappearance generated by 0.2 <~ Delta m^2 <~ 1 eV^2, which could be measured in future experiments.
2103.08222
Ali Osman Acar
Ali Osman Acar, Osman Emre Delialioglu, Saleh Sultansoy
A search for the first generation charged vector-like leptons at future colliders
arXiv admin note: text overlap with arXiv:1801.03927
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-nc-sa/4.0/
Flavor Democracy Hypothesis favors existence of iso-singlet quarks and vector-like charged leptons. Their observation at future colliders could shed light on the nature of mass and mixing patterns of known leptons and quarks, as well as Higgs boson itself. Vector-like quarks are extensively searched by ATLAS and CMS collaborations. Unfortunately, this is not the case for vector-like leptons, while they have actually similar status from phenomenology viewpoint. We argue that vector-like charged leptons should be included into the new physics search programs of future energy frontier colliders. It is shown that pair production at the HE-LHC with decay of one of the leptons to Ze and another to He channel, followed by H \rightarrow bb and Z \rightarrow \mu\mu decays will give opportunity to scan masses of iso-singlet and iso-doublet charged leptons up to 0.9 TeV and 1.5 TeV, respectively. FCC will extend this region up to 2 TeV for iso-singlet and 3.6 TeV for iso-doublet charged leptons.
[ { "created": "Mon, 15 Mar 2021 09:09:56 GMT", "version": "v1" } ]
2021-03-16
[ [ "Acar", "Ali Osman", "" ], [ "Delialioglu", "Osman Emre", "" ], [ "Sultansoy", "Saleh", "" ] ]
Flavor Democracy Hypothesis favors existence of iso-singlet quarks and vector-like charged leptons. Their observation at future colliders could shed light on the nature of mass and mixing patterns of known leptons and quarks, as well as Higgs boson itself. Vector-like quarks are extensively searched by ATLAS and CMS collaborations. Unfortunately, this is not the case for vector-like leptons, while they have actually similar status from phenomenology viewpoint. We argue that vector-like charged leptons should be included into the new physics search programs of future energy frontier colliders. It is shown that pair production at the HE-LHC with decay of one of the leptons to Ze and another to He channel, followed by H \rightarrow bb and Z \rightarrow \mu\mu decays will give opportunity to scan masses of iso-singlet and iso-doublet charged leptons up to 0.9 TeV and 1.5 TeV, respectively. FCC will extend this region up to 2 TeV for iso-singlet and 3.6 TeV for iso-doublet charged leptons.
hep-ph/0311114
Gideon Alexander
Gideon Alexander
Open Questions Related to Bose-Einstein Correlations in e+ e- --> Hadrons
Invited talk given at the ISMD2003, 5-11 September 2003, Krakow, Poland
Acta Phys.Polon. B35 (2004) 69-76
null
Tel-Aviv University Report TAUP-2750-03
hep-ph
null
Questions concerning the Bose-Einstein (BEC) and Fermi-Dirac (FDC) correlations of hadrons produced in $e^+e^-$ collisions are discussed. Among them the emitter dimension $r$ as a function of $\sqrt{s_{ee}}$ and the hadron mass, the extension of the BEC by including isospin invariance and the proposed relation between $r$ and the inter-atomic separation in Bose condensates.
[ { "created": "Mon, 10 Nov 2003 09:30:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Alexander", "Gideon", "" ] ]
Questions concerning the Bose-Einstein (BEC) and Fermi-Dirac (FDC) correlations of hadrons produced in $e^+e^-$ collisions are discussed. Among them the emitter dimension $r$ as a function of $\sqrt{s_{ee}}$ and the hadron mass, the extension of the BEC by including isospin invariance and the proposed relation between $r$ and the inter-atomic separation in Bose condensates.
1509.07407
Gabor Cynolter
G. Cynolter and E. Lendvai
Cutoff Regularization Method in Gauge Theories
22 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1002.4490, arXiv:1012.4648
null
null
ITP-Budapest 665
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Lorentz and gauge symmetry preserving regularization method is discussed in four dimension based on momentum cutoff. We use the conditions of gauge invariance or equivalently the freedom of shift of the loop momentum to define the evaluation of the terms carrying even number of Lorentz indices, e.g. proportional to $k_{\mu}k_{\nu}$. The remaining scalar integrals are calculated with a four dimensional momentum cutoff. The finite terms (independent of the cutoff) are free of ambiguities coming from subtractions in non-trivial cases. Finite parts of the result are equal with the results of dimensional regularization. The proposed method can be applied to various physical processes where the use of dimensional regularization is subtle or a physical cutoff is present. As a famous example it is shown that the triangle anomaly can be calculated unambiguously with this new improved cutoff.
[ { "created": "Thu, 24 Sep 2015 15:33:58 GMT", "version": "v1" } ]
2015-09-25
[ [ "Cynolter", "G.", "" ], [ "Lendvai", "E.", "" ] ]
A Lorentz and gauge symmetry preserving regularization method is discussed in four dimension based on momentum cutoff. We use the conditions of gauge invariance or equivalently the freedom of shift of the loop momentum to define the evaluation of the terms carrying even number of Lorentz indices, e.g. proportional to $k_{\mu}k_{\nu}$. The remaining scalar integrals are calculated with a four dimensional momentum cutoff. The finite terms (independent of the cutoff) are free of ambiguities coming from subtractions in non-trivial cases. Finite parts of the result are equal with the results of dimensional regularization. The proposed method can be applied to various physical processes where the use of dimensional regularization is subtle or a physical cutoff is present. As a famous example it is shown that the triangle anomaly can be calculated unambiguously with this new improved cutoff.
hep-ph/0405227
Seung-Il Nam
Seung-Il Nam, Atsushi Hosaka and Hyun-Chul Kim
Production of the pentaquark exotic baryon Xi_5 in bar{K} N scattering : bar{K} N -> K Xi_5 and bar{K} N -> K* Xi_5
8 pages and 15 figures
J.Korean Phys.Soc.52:561-567,2008
10.3938/jkps.52.561
PNU-NTG-07/2004 and PNU-NURI-06/2004
hep-ph nucl-th
null
We investigate the production of the newly found pentaquark exotic baryon Xi_5 in the bar{K} N -> K Xi_5 and the bar{K} N -> K* Xi_5 reactions at the tree level. We consider both positive- and negative parities of the Xi_5. The reactions are dominated by the s- and u-channel processes, and the resulting cross sections depend very much on the parity of Xi_5 and on the type of form factor. We have seen that the cross sections for the positive-parity Xi_5 are generally about a hundred times larger than those of the negative-parity one. This large difference in the cross sections will be useful for further study of pentaquark baryons.
[ { "created": "Mon, 24 May 2004 09:41:13 GMT", "version": "v1" }, { "created": "Tue, 22 Jan 2008 01:58:24 GMT", "version": "v2" } ]
2011-08-31
[ [ "Nam", "Seung-Il", "" ], [ "Hosaka", "Atsushi", "" ], [ "Kim", "Hyun-Chul", "" ] ]
We investigate the production of the newly found pentaquark exotic baryon Xi_5 in the bar{K} N -> K Xi_5 and the bar{K} N -> K* Xi_5 reactions at the tree level. We consider both positive- and negative parities of the Xi_5. The reactions are dominated by the s- and u-channel processes, and the resulting cross sections depend very much on the parity of Xi_5 and on the type of form factor. We have seen that the cross sections for the positive-parity Xi_5 are generally about a hundred times larger than those of the negative-parity one. This large difference in the cross sections will be useful for further study of pentaquark baryons.
2406.19447
Yong Xu
Nicol\'as Bernal, Julia Harz, Martin A. Mojahed, Yong Xu
Graviton- and Inflaton-mediated Dark Matter Production after Large Field Polynomial Inflation
22 pages, 6 figures
null
null
MITP-24-056
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Polynomial inflation is a simple cosmological scenario, which fits the cosmic microwave background data well. It provides testable predictions for the tensor-to-scalar ratio and the running of the spectral index. In this work, we investigate the production of Dirac dark matter (DM) within the framework of large-field polynomial inflation. We study all relevant production channels including $i$) non-thermal production through inflaton decays and scatterings, and $ii$) thermal production from scattering of standard model particles mediated by inflatons and gravitons. In contrast to small-field polynomial inflation, where inflaton decay dominates DM production, we find that graviton-mediated processes can be dominant in the large-field scenario. In particular, graviton-mediated scatterings can account for the observed relic abundance even when DM is up to one order of magnitude heavier than the inflaton. For DM lighter than the inflaton, we demonstrate that the interplay between graviton- and inflaton-mediated production channels give rise to non-trivial relations between the DM mass and the reheating temperature required to account for the DM relic abundance.
[ { "created": "Thu, 27 Jun 2024 18:00:01 GMT", "version": "v1" } ]
2024-07-01
[ [ "Bernal", "Nicolás", "" ], [ "Harz", "Julia", "" ], [ "Mojahed", "Martin A.", "" ], [ "Xu", "Yong", "" ] ]
Polynomial inflation is a simple cosmological scenario, which fits the cosmic microwave background data well. It provides testable predictions for the tensor-to-scalar ratio and the running of the spectral index. In this work, we investigate the production of Dirac dark matter (DM) within the framework of large-field polynomial inflation. We study all relevant production channels including $i$) non-thermal production through inflaton decays and scatterings, and $ii$) thermal production from scattering of standard model particles mediated by inflatons and gravitons. In contrast to small-field polynomial inflation, where inflaton decay dominates DM production, we find that graviton-mediated processes can be dominant in the large-field scenario. In particular, graviton-mediated scatterings can account for the observed relic abundance even when DM is up to one order of magnitude heavier than the inflaton. For DM lighter than the inflaton, we demonstrate that the interplay between graviton- and inflaton-mediated production channels give rise to non-trivial relations between the DM mass and the reheating temperature required to account for the DM relic abundance.
hep-ph/9811440
Thomas G. Rizzo
Thomas G. Rizzo
Distinguishing Indirect Signatures of New Physics at the NLC: Z' Versus R-Parity Violation
31 pages, 11 Figs, LaTex, discussion extended, refs updated, typos corrected
Phys.Rev. D59 (1999) 113004
10.1103/PhysRevD.59.113004
SLAC-PUB-7982
hep-ph
null
R-parity violation and extensions of the Standard Model gauge structure offer two non-minimal realizations of supersymmetry at low energies that can lead to similar new physics signatures at existing and future colliders. We discuss techniques that can be employed at the NLC below direct production threshold to distinguish these two new physics scenarios.
[ { "created": "Mon, 23 Nov 1998 16:47:30 GMT", "version": "v1" }, { "created": "Mon, 25 Jan 1999 20:43:20 GMT", "version": "v2" } ]
2009-10-31
[ [ "Rizzo", "Thomas G.", "" ] ]
R-parity violation and extensions of the Standard Model gauge structure offer two non-minimal realizations of supersymmetry at low energies that can lead to similar new physics signatures at existing and future colliders. We discuss techniques that can be employed at the NLC below direct production threshold to distinguish these two new physics scenarios.
0907.5316
Isaac Vidana
C.E. Jimenez-Tejero, A. Ramos and I. Vidana
Dynamically generated open charmed baryons beyond the zero range approximation
7 figures, 8 tables
Phys.Rev.C80:055206,2009
10.1103/PhysRevC.80.055206
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The interaction of the low lying pseudo-scalar mesons with the ground state baryons in the charm sector is studied within a coupled channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudo-scalar mesons off the ground-state baryons are obtained by solving the Lippmann--Schwinger equation. We analyze in detail the effects of going beyond the $t=0$ approximation. Our model predicts the dynamical generation of several open charmed baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.
[ { "created": "Thu, 30 Jul 2009 11:49:50 GMT", "version": "v1" }, { "created": "Thu, 26 Nov 2009 15:34:26 GMT", "version": "v2" } ]
2010-12-01
[ [ "Jimenez-Tejero", "C. E.", "" ], [ "Ramos", "A.", "" ], [ "Vidana", "I.", "" ] ]
The interaction of the low lying pseudo-scalar mesons with the ground state baryons in the charm sector is studied within a coupled channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudo-scalar mesons off the ground-state baryons are obtained by solving the Lippmann--Schwinger equation. We analyze in detail the effects of going beyond the $t=0$ approximation. Our model predicts the dynamical generation of several open charmed baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.
1505.02022
Cheuk-Yin Wong
Cheuk-Yin Wong, Grzegorz Wilk, Leonardo J.L. Cirto, Constantino Tsallis
From QCD-based hard-scattering to nonextensive statistical mechanical descriptions of transverse momentum spectra in high-energy $pp$ and $p\bar p$ collisions
15 pages, 8 figures
Phys. Rev. D91 114027 (2015)
10.1103/PhysRevD.91.114027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse spectra of both jets and hadrons obtained in high-energy $pp$ and $p\bar p $ collisions at central rapidity exhibit power-law behavior of $1/p_T^n$ at high $p_T$. The power index $n$ is 4-5 for jet production and is 6-10 for hadron production. Furthermore, the hadron spectra spanning over 14 orders of magnitude down to the lowest $p_T$ region in $pp$ collisions at LHC can be adequately described by a single nonextensive statistical mechanical distribution that is widely used in other branches of science. This suggests indirectly the possible dominance of the hard-scattering process over essentially the whole $p_T$ region at central rapidity in high-energy $pp$ and $p \bar p$ collisions. We show here direct evidences of such a dominance of the hard-scattering process by investigating the power indices of UA1 and ATLAS jet spectra over an extended $p_T$ region and the two-particle correlation data of the STAR and PHENIX Collaborations in high-energy $pp$ and $p \bar p$ collisions at central rapidity. We then study how the showering of the hard-scattering product partons alters the power index of the hadron spectra and leads to a hadron distribution that may be cast into a single-particle nonextensive statistical mechanical distribution. Because of such a connection, the nonextensive statistical mechanical distribution may be considered as a lowest-order approximation of the hard-scattering of partons followed by the subsequent process of parton showering that turns the jets into hadrons, in high energy $pp$ and $p\bar p$ collisions.
[ { "created": "Fri, 8 May 2015 13:00:48 GMT", "version": "v1" } ]
2015-06-24
[ [ "Wong", "Cheuk-Yin", "" ], [ "Wilk", "Grzegorz", "" ], [ "Cirto", "Leonardo J. L.", "" ], [ "Tsallis", "Constantino", "" ] ]
Transverse spectra of both jets and hadrons obtained in high-energy $pp$ and $p\bar p $ collisions at central rapidity exhibit power-law behavior of $1/p_T^n$ at high $p_T$. The power index $n$ is 4-5 for jet production and is 6-10 for hadron production. Furthermore, the hadron spectra spanning over 14 orders of magnitude down to the lowest $p_T$ region in $pp$ collisions at LHC can be adequately described by a single nonextensive statistical mechanical distribution that is widely used in other branches of science. This suggests indirectly the possible dominance of the hard-scattering process over essentially the whole $p_T$ region at central rapidity in high-energy $pp$ and $p \bar p$ collisions. We show here direct evidences of such a dominance of the hard-scattering process by investigating the power indices of UA1 and ATLAS jet spectra over an extended $p_T$ region and the two-particle correlation data of the STAR and PHENIX Collaborations in high-energy $pp$ and $p \bar p$ collisions at central rapidity. We then study how the showering of the hard-scattering product partons alters the power index of the hadron spectra and leads to a hadron distribution that may be cast into a single-particle nonextensive statistical mechanical distribution. Because of such a connection, the nonextensive statistical mechanical distribution may be considered as a lowest-order approximation of the hard-scattering of partons followed by the subsequent process of parton showering that turns the jets into hadrons, in high energy $pp$ and $p\bar p$ collisions.
hep-ph/9311363
Stefan Dittmaier
S.Dittmaier
Full O(alpha) Radiative Corrections to High-Energy Compton Scattering
20 pages, LaTex (uuencoded figures appended on tex-file), Bi-TP 93/61
Nucl.Phys. B423 (1994) 384-404
10.1016/0550-3213(94)90139-2
null
hep-ph
null
Using computer-algebraic methods we derive compact analytical expressions for the virtual electroweak radiative corrections to polarized Compton scattering. Moreover the helicity amplitudes for double Compton scattering, which prove to be extremely simple in terms of Weyl-van der Waerden spinor products, are presented for massless electrons. The inclusion of a finite electron mass is described, too. Finally numerical results both for the purely photonic and the full O(alpha) electroweak corrections, which turn out to be of the order of 5-10%, are discussed for energies ranging from 10GeV to 2TeV.
[ { "created": "Thu, 25 Nov 1993 13:39:58 GMT", "version": "v1" } ]
2009-10-22
[ [ "Dittmaier", "S.", "" ] ]
Using computer-algebraic methods we derive compact analytical expressions for the virtual electroweak radiative corrections to polarized Compton scattering. Moreover the helicity amplitudes for double Compton scattering, which prove to be extremely simple in terms of Weyl-van der Waerden spinor products, are presented for massless electrons. The inclusion of a finite electron mass is described, too. Finally numerical results both for the purely photonic and the full O(alpha) electroweak corrections, which turn out to be of the order of 5-10%, are discussed for energies ranging from 10GeV to 2TeV.
hep-ph/9408362
null
Charles B. Chiu and Duane A. Dicus
Dips in Partial Wave Amplitudes from Final State Interactions
9 pages, CPP-93-21, 6 figures not included
Phys.Rev. D50 (1994) 6724-6729
10.1103/PhysRevD.50.6724
null
hep-ph
null
We consider the dip-peak structures in the J=0 partial wave amplitudes for processes $\gamma\gamma\rightarrow W^+W^-~ \mbox{and}~\gamma\gamma,gg\rightarrow t\overline{t}$ taking into account the corresponding Born term process and the rescattering process where the intermediate state is rescattered through the exchange of Higgs resonance state in the direct channel.
[ { "created": "Wed, 24 Aug 1994 19:23:18 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chiu", "Charles B.", "" ], [ "Dicus", "Duane A.", "" ] ]
We consider the dip-peak structures in the J=0 partial wave amplitudes for processes $\gamma\gamma\rightarrow W^+W^-~ \mbox{and}~\gamma\gamma,gg\rightarrow t\overline{t}$ taking into account the corresponding Born term process and the rescattering process where the intermediate state is rescattered through the exchange of Higgs resonance state in the direct channel.
1510.07265
Daniel Cabrera
Daniel Cabrera, Laura Tolos, J\"org Aichelin and Elena bratkovskaya
Strange meson-baryon interaction in hot and dense medium: recent progress for a road to GSI/FAIR
4 pages, 2 figures. To be published in the Proceedings of the 15th International Conference on Strangeness in Quark Matter (SQM2015), 6-11 July 2015, JINR, Dubna, Russia
null
10.1088/1742-6596/668/1/012048
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report recent results on the dynamics of strange hadrons in two-body reactions relevant for near-threshold production in heavy-ion collisions at GSI/FAIR and NICA-Dubna. In particular, $\bar K N$ scattering in hot and dense nuclear matter is studied within a chiral unitary framework in coupled channels, setting up the starting point for implementations in microscopic off-shell transport approaches. We focus on the calculation of transition rates with special attention to the excitation of hyperon resonances and isospin effects. Additionally, we explore "unconventional" strangeness generation by meson-meson and meson-baryon interactions in connection with recent HADES observations of deep sub-threshold $\phi$ and $\Xi$ production.
[ { "created": "Sun, 25 Oct 2015 16:39:19 GMT", "version": "v1" } ]
2016-02-17
[ [ "Cabrera", "Daniel", "" ], [ "Tolos", "Laura", "" ], [ "Aichelin", "Jörg", "" ], [ "bratkovskaya", "Elena", "" ] ]
We report recent results on the dynamics of strange hadrons in two-body reactions relevant for near-threshold production in heavy-ion collisions at GSI/FAIR and NICA-Dubna. In particular, $\bar K N$ scattering in hot and dense nuclear matter is studied within a chiral unitary framework in coupled channels, setting up the starting point for implementations in microscopic off-shell transport approaches. We focus on the calculation of transition rates with special attention to the excitation of hyperon resonances and isospin effects. Additionally, we explore "unconventional" strangeness generation by meson-meson and meson-baryon interactions in connection with recent HADES observations of deep sub-threshold $\phi$ and $\Xi$ production.
1005.5001
James Cline
James M. Cline
Excited Dark Matter versus PAMELA/Fermi
4 pages, presented at Moriond Cosmology 2010
null
null
CERN-PH-TH/2010-101
hep-ph astro-ph.CO astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Excitation of multicomponent dark matter in the galactic center has been proposed as the source of low-energy positrons that produce the excess 511 keV gamma rays that have been observed by INTEGRAL. Such models have also been promoted to explain excess high-energy electrons/positrons observed by the PAMELA, Fermi/LAT and H.E.S.S. experiments. We investigate whether one model can simultaneously fit all three anomalies, in addition to further constraints from inverse Compton scattering by the high-energy leptons. We find models that fit both the 511 keV and PAMELA excesses at dark matter masses M < 400 GeV, but not the Fermi lepton excess. The conflict arises because a more cuspy DM halo profile is needed to match the observed 511 keV signal than is compatible with inverse Compton constraints at larger DM masses.
[ { "created": "Thu, 27 May 2010 08:04:54 GMT", "version": "v1" } ]
2010-05-28
[ [ "Cline", "James M.", "" ] ]
Excitation of multicomponent dark matter in the galactic center has been proposed as the source of low-energy positrons that produce the excess 511 keV gamma rays that have been observed by INTEGRAL. Such models have also been promoted to explain excess high-energy electrons/positrons observed by the PAMELA, Fermi/LAT and H.E.S.S. experiments. We investigate whether one model can simultaneously fit all three anomalies, in addition to further constraints from inverse Compton scattering by the high-energy leptons. We find models that fit both the 511 keV and PAMELA excesses at dark matter masses M < 400 GeV, but not the Fermi lepton excess. The conflict arises because a more cuspy DM halo profile is needed to match the observed 511 keV signal than is compatible with inverse Compton constraints at larger DM masses.
hep-ph/9810379
Keum Yong-Yeon
Y. M. Cho and Y.-Y. Keum
Dilatonic Dark Matter
12 pages, 1 figure. Published in Mod. Phys. Lett A13 (1998) 109-117. This essay received an "honorable mention" from the Gravity Research Foundation, 1997
Mod.Phys.Lett. A13 (1998) 109-117
10.1142/S0217732398000152
APCTP/97-01 (revised)
hep-ph
null
We study the possibility that the dilaton plays the role of the dark matter of the universe. We find that the condition for the dilaton to be the dark matter of the universe strongly restricts its mass to be around 0.5 keV or 270 MeV. For the other mass ranges, the dilaton either undercloses or overcloses the universe. The 0.5 keV dilaton has the free-streaming distance of about 1.4 Mpc and becomes an excellent candidate of a warm dark matter, while the 270 MeV one has the free-streaming distance of about 7.4 pc and becomes a cold dark matter. We discuss the possible ways to detect the dilaton experimentally.
[ { "created": "Fri, 16 Oct 1998 04:07:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cho", "Y. M.", "" ], [ "Keum", "Y. -Y.", "" ] ]
We study the possibility that the dilaton plays the role of the dark matter of the universe. We find that the condition for the dilaton to be the dark matter of the universe strongly restricts its mass to be around 0.5 keV or 270 MeV. For the other mass ranges, the dilaton either undercloses or overcloses the universe. The 0.5 keV dilaton has the free-streaming distance of about 1.4 Mpc and becomes an excellent candidate of a warm dark matter, while the 270 MeV one has the free-streaming distance of about 7.4 pc and becomes a cold dark matter. We discuss the possible ways to detect the dilaton experimentally.
1510.05907
Enis Yazici
E. Yazici, H. Sundu, E. Veli Veliev
$ B_c B_c J/\psi $ Vertex Form Factor at Finite Temperature in the Framework of QCD Sum Rules Approach
8 pages, 7 figures
Eur. Phys. J. C (2016) 76:89
10.1140/epjc/s10052-016-3929-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strong form factor of the $B_{c} B_{c}J/\Psi$ vertex is calculated in the framework of the QCD sum rules method at finite temperature. Taking into account additional operators appearing at finite temperature, thermal Wilson expansion is obtained and QCD sum rules are derived. While increasing temperature, the strong form factor remains unchanged up to $T\simeq100~MeV$ but slightly increases after this point. After $T\simeq160~MeV$, the form factor suddenly decreases up to $T\simeq170~MeV$. The obtained result of the coupling constant by fitting the form factor at $Q^2=-m^2_{offshell}$ at $T=0$ is in a very good agreement with the QCD sum rules calculations at vacuum. Our prediction can be checked in the future experiments.
[ { "created": "Tue, 20 Oct 2015 14:18:07 GMT", "version": "v1" }, { "created": "Fri, 15 Jan 2016 09:13:36 GMT", "version": "v2" } ]
2016-10-28
[ [ "Yazici", "E.", "" ], [ "Sundu", "H.", "" ], [ "Veliev", "E. Veli", "" ] ]
The strong form factor of the $B_{c} B_{c}J/\Psi$ vertex is calculated in the framework of the QCD sum rules method at finite temperature. Taking into account additional operators appearing at finite temperature, thermal Wilson expansion is obtained and QCD sum rules are derived. While increasing temperature, the strong form factor remains unchanged up to $T\simeq100~MeV$ but slightly increases after this point. After $T\simeq160~MeV$, the form factor suddenly decreases up to $T\simeq170~MeV$. The obtained result of the coupling constant by fitting the form factor at $Q^2=-m^2_{offshell}$ at $T=0$ is in a very good agreement with the QCD sum rules calculations at vacuum. Our prediction can be checked in the future experiments.
hep-ph/9407244
Bob Holdom
B. Holdom
A Dynamical Origin for the Top Mass
10 pages, LaTeX, NSF-ITP-94-68
Phys.Lett. B336 (1994) 85-90
10.1016/0370-2693(94)00985-6
null
hep-ph
null
We describe a dynamical scheme by which isospin breaking feeds strongly into the $t$ and $b$ masses and not into the $W$ and $Z$ masses. The third family feels a new gauge interaction broken close to a TeV.
[ { "created": "Wed, 6 Jul 1994 19:24:56 GMT", "version": "v1" } ]
2009-10-28
[ [ "Holdom", "B.", "" ] ]
We describe a dynamical scheme by which isospin breaking feeds strongly into the $t$ and $b$ masses and not into the $W$ and $Z$ masses. The third family feels a new gauge interaction broken close to a TeV.
1209.0918
Nodoka Yamanaka
Nodoka Yamanaka, Toru Sato, Takahiro Kubota
R-parity violating supersymmetric contributions to the neutron beta decay at the one-loop level
13 pages, 6 figures, minor corrections
Phys.Rev. D86 (2012) 075032
10.1103/PhysRevD.86.075032
OU-HET 758
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The contribution of the R-parity violating minimal supersymmetric standard model to the neutron beta decay at the one-loop level is investigated. It is found that the baryon number and R-parity violating interactions contribute to the D correlation through one-loop corrections, while the tree level prediction is vanishing. The Fierz interference term is also investigated at the one-loop level by considering the lepton number and R-parity violating interactions. We show that future experimental progress can provide us with better constraints on some of the combinations of R-parity violating couplings.
[ { "created": "Wed, 5 Sep 2012 10:31:04 GMT", "version": "v1" }, { "created": "Wed, 31 Oct 2012 18:39:58 GMT", "version": "v2" } ]
2012-11-01
[ [ "Yamanaka", "Nodoka", "" ], [ "Sato", "Toru", "" ], [ "Kubota", "Takahiro", "" ] ]
The contribution of the R-parity violating minimal supersymmetric standard model to the neutron beta decay at the one-loop level is investigated. It is found that the baryon number and R-parity violating interactions contribute to the D correlation through one-loop corrections, while the tree level prediction is vanishing. The Fierz interference term is also investigated at the one-loop level by considering the lepton number and R-parity violating interactions. We show that future experimental progress can provide us with better constraints on some of the combinations of R-parity violating couplings.
0705.3802
Alexander Lenz
Alexander Lenz
Theoretical status of $B_s$-mixing and lifetimes of heavy hadrons
6 pages, invited talk at Hadron Collider Physics Symposium 2007, La Biodola, Isola d'Elba, Italy, misprints in Note added corrected
Nucl.Phys.Proc.Suppl.177-178:81-86,2008
10.1016/j.nuclphysbps.2007.11.089
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the theoretical status of the lifetime ratios $\tau_{B^+} / \tau_{B_d}$, $\tau_{B_s} / \tau_{B_d}$, $\tau_{\Lambda_b} / \tau_{B_d}$ and $\tau_{B_c}$ and of the mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$. $\Delta M_s$ and $\Delta \Gamma_s$ suffer from large uncertainties due to the badly known decay constants, while the ratio $\Delta \Gamma_s / \Delta M_s$ can be determined with almost no non-perturbative uncertainties, therefore it can be used perfectly to find possible new physics contributions in the mixing parameters. We suggest a very clear method of visualizing the bounds on new physics and demonstrate this by combining the latest experimental numbers on the mixing quantities quantities with theory - one already gets some hints for new physics contributions, but more precise experimental numbers are needed to draw some definite conclusions. We conclude with a ranking list of all the discussed quantities according to their current theoretical uncertainties and point out possible improvements.
[ { "created": "Fri, 25 May 2007 16:08:56 GMT", "version": "v1" }, { "created": "Mon, 28 May 2007 12:02:54 GMT", "version": "v2" }, { "created": "Sun, 1 Jul 2012 16:47:34 GMT", "version": "v3" } ]
2012-07-03
[ [ "Lenz", "Alexander", "" ] ]
We review the theoretical status of the lifetime ratios $\tau_{B^+} / \tau_{B_d}$, $\tau_{B_s} / \tau_{B_d}$, $\tau_{\Lambda_b} / \tau_{B_d}$ and $\tau_{B_c}$ and of the mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$. $\Delta M_s$ and $\Delta \Gamma_s$ suffer from large uncertainties due to the badly known decay constants, while the ratio $\Delta \Gamma_s / \Delta M_s$ can be determined with almost no non-perturbative uncertainties, therefore it can be used perfectly to find possible new physics contributions in the mixing parameters. We suggest a very clear method of visualizing the bounds on new physics and demonstrate this by combining the latest experimental numbers on the mixing quantities quantities with theory - one already gets some hints for new physics contributions, but more precise experimental numbers are needed to draw some definite conclusions. We conclude with a ranking list of all the discussed quantities according to their current theoretical uncertainties and point out possible improvements.
hep-ph/9610219
Lubov Vassilevskaya
A.A. Gvozdev, N.V. Mikheev and L.A. Vassilevskaya
The radiative decay of the massive neutrino in the external electromagnetic fields
33 pages, latex, 3 ps-figures. To be published in Phys. Rev., V. D54
Phys.Rev.D54:5674-5685,1996
10.1103/PhysRevD.54.5674
YARU-HE-96/02
hep-ph
null
The radiative decay of the massive neutrino $\nu_i \rightarrow \nu_j \gamma$ is investigated in the framework of the Standard Model in external electromagnetic fields of various configurations: constant crossed field, constant uniform magnetic field, plane monochromatic wave's field. The effect of significant enhancement of the neutrino decay probability by the external field (electromagnetic catalysis) is discussed. An especially strong enhancement occurs in the case of the ultrarelativistic neutrino decay, since in this case the decay probability does not contain suppression caused by the smallness of the decaying neutrino mass. The ultrarelativistic neutrino decay catalysis is significant even in a relatively weak external field ($F/F_e << 1$, where $F_e$ is the critical Schwinger value). The expression for the photon splitting probability into the neutrino pair $\gamma \rightarrow \nu_i \bar\nu_j$ in the wave field is given. The estimations of a number of gamma-quanta produced in a volume filled with an electromagnetic field and the neutrino lifetime in a strong magnetic field are presented.
[ { "created": "Wed, 2 Oct 1996 15:33:18 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gvozdev", "A. A.", "" ], [ "Mikheev", "N. V.", "" ], [ "Vassilevskaya", "L. A.", "" ] ]
The radiative decay of the massive neutrino $\nu_i \rightarrow \nu_j \gamma$ is investigated in the framework of the Standard Model in external electromagnetic fields of various configurations: constant crossed field, constant uniform magnetic field, plane monochromatic wave's field. The effect of significant enhancement of the neutrino decay probability by the external field (electromagnetic catalysis) is discussed. An especially strong enhancement occurs in the case of the ultrarelativistic neutrino decay, since in this case the decay probability does not contain suppression caused by the smallness of the decaying neutrino mass. The ultrarelativistic neutrino decay catalysis is significant even in a relatively weak external field ($F/F_e << 1$, where $F_e$ is the critical Schwinger value). The expression for the photon splitting probability into the neutrino pair $\gamma \rightarrow \nu_i \bar\nu_j$ in the wave field is given. The estimations of a number of gamma-quanta produced in a volume filled with an electromagnetic field and the neutrino lifetime in a strong magnetic field are presented.
1011.5176
Enrique Ruiz Arriola
Enrique Ruiz Arriola, Wojciech Broniowski
Scalar-isoscalar states, gravitational form factors, and dimension-2 condensates in a large-Nc Regge approach
Talk given at the 9th Conference On Quark Confinement and the Hadron Spectrum (Confinement IX), 30 Aug. - 3 Sept. 2010, Madrid, Spain
AIP Conf.Proc.1343:361-363,2011
10.1063/1.3575030
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scalar-isoscalar states are analyzed within the large-Nc Regge approach. We find that the lightest f0(600) scalar-isoscalar state fits very well into the pattern of the radial Regge trajectory. We confirm the obtained mass values from an analysis of the pion and nucleon spin-0 gravitational form factors, recently measured on the lattice. We find that a simple two-state model suggests a meson nature of f0(600), and a glueball nature of f0(980), which naturally explains the ratios of various coupling constants. Finally, matching to the OPE requires a fine-tuned mass condition of the vanishing dimension-2 condensate in the Regge approach with infinitely many scalar-isoscalar states.
[ { "created": "Tue, 23 Nov 2010 17:41:35 GMT", "version": "v1" } ]
2011-07-15
[ [ "Arriola", "Enrique Ruiz", "" ], [ "Broniowski", "Wojciech", "" ] ]
Scalar-isoscalar states are analyzed within the large-Nc Regge approach. We find that the lightest f0(600) scalar-isoscalar state fits very well into the pattern of the radial Regge trajectory. We confirm the obtained mass values from an analysis of the pion and nucleon spin-0 gravitational form factors, recently measured on the lattice. We find that a simple two-state model suggests a meson nature of f0(600), and a glueball nature of f0(980), which naturally explains the ratios of various coupling constants. Finally, matching to the OPE requires a fine-tuned mass condition of the vanishing dimension-2 condensate in the Regge approach with infinitely many scalar-isoscalar states.
hep-ph/9608359
null
K.-I. Izawa and T. Yanagida
Natural New Inflation in Broken Supergravity
12 pages, latex
Phys.Lett.B393:331-336,1997
10.1016/S0370-2693(96)01638-3
UT-757
hep-ph
null
We consider a natural new inflationary model in broken supergravity based on an R symmetry. The model predicts a concrete relation between the amplitude of primordial density fluctuations and the scale of supersymmetry breaking. The observed value of the density fluctuations is obtained for the gravitino mass of order the weak scale along with a power-law spectral index considerably less than one, which may be tested in future observations.
[ { "created": "Mon, 19 Aug 1996 07:28:10 GMT", "version": "v1" }, { "created": "Thu, 12 Dec 1996 06:26:26 GMT", "version": "v2" } ]
2011-07-19
[ [ "Izawa", "K. -I.", "" ], [ "Yanagida", "T.", "" ] ]
We consider a natural new inflationary model in broken supergravity based on an R symmetry. The model predicts a concrete relation between the amplitude of primordial density fluctuations and the scale of supersymmetry breaking. The observed value of the density fluctuations is obtained for the gravitino mass of order the weak scale along with a power-law spectral index considerably less than one, which may be tested in future observations.
hep-ph/9708386
Vladimir Braun
V.M. Braun
Ultraviolet dominance of power corrections in QCD?
7 pages, LATEX, no figures; Presented at 5th International Conference on Physics Beyond the Standard Model, Balholm, Norway, 29 Apr - 4May 1997
null
10.1063/1.54481
NORDITA 97/53-P
hep-ph
null
I explain current theoretical ideas on higher-twist (hadronization) corrections to physical observables in QCD.
[ { "created": "Mon, 18 Aug 1997 12:31:55 GMT", "version": "v1" }, { "created": "Tue, 19 Aug 1997 15:43:07 GMT", "version": "v2" } ]
2009-10-30
[ [ "Braun", "V. M.", "" ] ]
I explain current theoretical ideas on higher-twist (hadronization) corrections to physical observables in QCD.
hep-ph/0511129
Xiao-Hong Wu
Chao-Shang Huang, Pyungwon Ko, Xiao-Hong Wu, Ya-Dong Yang
MSSM Anatomy of the Polarization Puzzle in B --> phi K* Decays
15 pages, 5 figures, minor revision and references added
Phys.Rev.D73:034026,2006
10.1103/PhysRevD.73.034026
null
hep-ph
null
We analyze the $B \to \phi K^{*}$ polarization puzzle in the Minimal Supersymmetric Standard Model (MSSM) including the neutral Higgs boson (NHB) contributions. To calculate the non-factorizable contributions to hadronic matrix elements of operators, we have used the QCD factorization framework to the $\alpha_s $ order. It is shown that the recent experimental results of the polarization fractions in $B\to \phi K^{*}$ decays, which are difficult to be explained in SM, could be explained in MSSM if there are flavor non-diagonal squark mass matrix elements of 2nd and 3rd generations, which also satisfy all relevant constraints from known experiments ($B\to X_s\gamma, B_s\to \mu^+\mu^-, B\to X_s \mu^+\mu^-, B\to X_s g, \Delta M_s$, etc.). We have shown in details that the experimental results can be accommodated with the flavor non-diagonal mass insertion of chirality RL, RL+LR, RR, or LL+ RR when the NHB contributions as well as $\mathcal{O}(\alpha_s)$ corrections of hadronic matrix elements of operators are included. However the branching ratios for the decay are smaller than the experimental measurements.
[ { "created": "Thu, 10 Nov 2005 13:06:47 GMT", "version": "v1" }, { "created": "Fri, 3 Feb 2006 12:22:28 GMT", "version": "v2" } ]
2011-03-23
[ [ "Huang", "Chao-Shang", "" ], [ "Ko", "Pyungwon", "" ], [ "Wu", "Xiao-Hong", "" ], [ "Yang", "Ya-Dong", "" ] ]
We analyze the $B \to \phi K^{*}$ polarization puzzle in the Minimal Supersymmetric Standard Model (MSSM) including the neutral Higgs boson (NHB) contributions. To calculate the non-factorizable contributions to hadronic matrix elements of operators, we have used the QCD factorization framework to the $\alpha_s $ order. It is shown that the recent experimental results of the polarization fractions in $B\to \phi K^{*}$ decays, which are difficult to be explained in SM, could be explained in MSSM if there are flavor non-diagonal squark mass matrix elements of 2nd and 3rd generations, which also satisfy all relevant constraints from known experiments ($B\to X_s\gamma, B_s\to \mu^+\mu^-, B\to X_s \mu^+\mu^-, B\to X_s g, \Delta M_s$, etc.). We have shown in details that the experimental results can be accommodated with the flavor non-diagonal mass insertion of chirality RL, RL+LR, RR, or LL+ RR when the NHB contributions as well as $\mathcal{O}(\alpha_s)$ corrections of hadronic matrix elements of operators are included. However the branching ratios for the decay are smaller than the experimental measurements.
hep-ph/9704365
Raul Horvat
R. Horvat (IRB Zagreb)
On finite--temperature and --density radiative corrections to the neutrino effective potential in the early Universe
11 pages, revtex style
Mod.Phys.Lett.A12:2461-2468,1997
10.1142/S0217732397002570
null
hep-ph
null
Finite-temperature and -density radiative corrections to the neutrino effective potential in the otherwise CP-symmetric early Universe are considered in the real-time approach of Thermal Field Theory. A consistent perturbation theory endowed with the hard thermal loop resummation techniques developed by Braaten and Pisarski is applied. Special attention is focused on the question whether such corrections can generate any nonzero contribution to the CP-symmetric part of the neutrino potential, if the contact approximation for the W-propagator is used.
[ { "created": "Mon, 21 Apr 1997 19:27:52 GMT", "version": "v1" } ]
2011-03-10
[ [ "Horvat", "R.", "", "IRB Zagreb" ] ]
Finite-temperature and -density radiative corrections to the neutrino effective potential in the otherwise CP-symmetric early Universe are considered in the real-time approach of Thermal Field Theory. A consistent perturbation theory endowed with the hard thermal loop resummation techniques developed by Braaten and Pisarski is applied. Special attention is focused on the question whether such corrections can generate any nonzero contribution to the CP-symmetric part of the neutrino potential, if the contact approximation for the W-propagator is used.
2009.07195
Vladimir Sauli
Vladimir Sauli
Regularization and renormalization scheme with diminished UV divergences
Since crucial error was found in v1 the regularization/renormalization scheme has changed and results have been recalculated according to changes. New section devoted to gluon polarization function added, section which concerns ABJ anomaly is shortened, 14 pages
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present new regularization/renormalization scheme, which is based on utilization of further auxiliary Feynman parameter integral. The later is used in order to make momentum integration finite before it is actually performed. In this way all singularities are submitted to the auxiliary integral leaving as with the finite non-polynomial structure known from the dimensional renormalization scheme. In order to preserve renormalizability and gauge invariance in proposed computational scheme we formulate the additional conditions which regulators dependent (infinite) part of correlator must obey. The question of absence(presence) of quadratic divergences is discussed and calculated at one loop approximation for QCD vacuum polarization, photon polarization function as well as for the Higgs mass function in the Standard Model. The way how anomaly is exhibited and how to deal with overlapping divergences is shortly discussed as well.
[ { "created": "Tue, 15 Sep 2020 16:09:06 GMT", "version": "v1" }, { "created": "Wed, 6 Jan 2021 18:28:32 GMT", "version": "v2" } ]
2021-01-07
[ [ "Sauli", "Vladimir", "" ] ]
We present new regularization/renormalization scheme, which is based on utilization of further auxiliary Feynman parameter integral. The later is used in order to make momentum integration finite before it is actually performed. In this way all singularities are submitted to the auxiliary integral leaving as with the finite non-polynomial structure known from the dimensional renormalization scheme. In order to preserve renormalizability and gauge invariance in proposed computational scheme we formulate the additional conditions which regulators dependent (infinite) part of correlator must obey. The question of absence(presence) of quadratic divergences is discussed and calculated at one loop approximation for QCD vacuum polarization, photon polarization function as well as for the Higgs mass function in the Standard Model. The way how anomaly is exhibited and how to deal with overlapping divergences is shortly discussed as well.
hep-ph/0412037
Claudio Coriano
A. Cafarella, Claudio Coriano` and T.N. Tomaras
QCD Supersymmetry and Low Energy Gravity
Contributed paper to the Conference "Quark confinement ant the Hadron Spectrum VI 2004". Latex, 3 pages
null
10.1063/1.1921024
null
hep-ph
null
In this contributed paper we discuss some aspects of scenarios with Extra Dimensions at the LHC and in cosmic rays.
[ { "created": "Thu, 2 Dec 2004 20:06:51 GMT", "version": "v1" }, { "created": "Thu, 2 Dec 2004 22:14:23 GMT", "version": "v2" } ]
2009-11-10
[ [ "Cafarella", "A.", "" ], [ "Coriano`", "Claudio", "" ], [ "Tomaras", "T. N.", "" ] ]
In this contributed paper we discuss some aspects of scenarios with Extra Dimensions at the LHC and in cosmic rays.
hep-ph/9804260
Herbert Weigel
H. Weigel (Tuebingen U.)
Radial excitations of low--lying baryons and the $Z^+$ penta--quark
21 pages, 9 (e)ps-f, to be published in Euro. Phys. J. A
Eur.Phys.J.A2:391,1998
10.1007/s100500050136
UNITU-THEP-7/1998
hep-ph nucl-th
null
Within an extended Skyrme soliton model for baryons the interplay between the collective radial motion and the SU(3)--flavor--rotations is investigated. The coupling between these modes is mediated by flavor symmetry breaking. Collective coordinates which describe the corresponding large amplitude fluctuations are introduced and treated canonically. When diagonalizing the resulting Hamiltonian flavor symmetry breaking is fully taken into consideration. As eigenstates not only the low--lying ${1/2}^+$ and ${3/2}^+$ baryons but also their radial excitations are obtained and compared to the empirical data. In particular the relevance of radial excitations for the penta--quark baryon $Z^+$ (Y=2, I=0, $J^\pi={1/2}^+$) is discussed. In this approach its mass is predicted to be $1.58{\rm GeV}$. Furthermore the widths for various hadronic decays are estimated which, for example, yields $\Gamma(Z^+\to NK)\sim 100{\rm MeV}$ for the only permissible decay process of the $Z^+$.
[ { "created": "Wed, 8 Apr 1998 17:43:09 GMT", "version": "v1" }, { "created": "Tue, 16 Jun 1998 16:36:10 GMT", "version": "v2" } ]
2009-09-25
[ [ "Weigel", "H.", "", "Tuebingen U." ] ]
Within an extended Skyrme soliton model for baryons the interplay between the collective radial motion and the SU(3)--flavor--rotations is investigated. The coupling between these modes is mediated by flavor symmetry breaking. Collective coordinates which describe the corresponding large amplitude fluctuations are introduced and treated canonically. When diagonalizing the resulting Hamiltonian flavor symmetry breaking is fully taken into consideration. As eigenstates not only the low--lying ${1/2}^+$ and ${3/2}^+$ baryons but also their radial excitations are obtained and compared to the empirical data. In particular the relevance of radial excitations for the penta--quark baryon $Z^+$ (Y=2, I=0, $J^\pi={1/2}^+$) is discussed. In this approach its mass is predicted to be $1.58{\rm GeV}$. Furthermore the widths for various hadronic decays are estimated which, for example, yields $\Gamma(Z^+\to NK)\sim 100{\rm MeV}$ for the only permissible decay process of the $Z^+$.
1210.4655
T. Lappi
T. Lappi and H. M\"antysaari
Forward particle correlations in the color glass condensate
4 pages, 5 figures, talk by T.L. at Quark Matter 2012, Washington DC, August 13-18 2012
Nucl.Phys.A904-905 2013 (2013) 807c-810c
10.1016/j.nuclphysa.2013.02.139
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiparticle correlations, such as forward dihadron correlations in pA collisions, are an important probe of the strong color fields that dominate the initial stages of a heavy ion collision. We describe recent progress in understanding two-particle correlations in the dilute-dense system, e.g. at forward rapidity in deuteron-gold collisions. This requires evaluating higher point Wilson line correlators from the JIMWLK equation, which we find well described by a Gaussian approximation. We then calculate the dihadron correlation, including both the "elastic" and "inelastic" contributions, and show that our result includes the double parton scattering contribution.
[ { "created": "Wed, 17 Oct 2012 07:45:59 GMT", "version": "v1" } ]
2013-08-14
[ [ "Lappi", "T.", "" ], [ "Mäntysaari", "H.", "" ] ]
Multiparticle correlations, such as forward dihadron correlations in pA collisions, are an important probe of the strong color fields that dominate the initial stages of a heavy ion collision. We describe recent progress in understanding two-particle correlations in the dilute-dense system, e.g. at forward rapidity in deuteron-gold collisions. This requires evaluating higher point Wilson line correlators from the JIMWLK equation, which we find well described by a Gaussian approximation. We then calculate the dihadron correlation, including both the "elastic" and "inelastic" contributions, and show that our result includes the double parton scattering contribution.
1208.3020
Stanley J. Brodsky
Stanley J. Brodsky and Guy de Teramond
Light-Front Holography and the Light-Front Schrodinger Equation
Invited talk, presented by SJB at the QCD Evolution Workshop, May 14 - 17, 2012, Thomas Jefferson National Accelerator Facility, Newport News, Virginia
null
10.1142/S2010194512009099
SLAC-PUB-15211
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the most important nonperturbative methods for solving QCD is quantization at fixed light-front time, \tau = t+z/c -- Dirac's "Front Form". The eigenvalues of the light-front QCD Hamiltonian predict the hadron spectrum and the eigensolutions provide the light-front wavefunctions which describe hadron structure. More generally, we show that the valence Fock-state wavefunctions of the light-front QCD Hamiltonian satisfy a single-variable relativistic equation of motion, analogous to the nonrelativistic radial Schr\"odinger equation, with an effective confining potential U which systematically incorporates the effects of higher quark and gluon Fock states. We outline a method for computing the required potential from first principles in QCD. The holographic mapping of gravity in AdS space to QCD, quantized at fixed light-front time, yields the same light front Schr\"odinger equation; in fact, the soft-wall AdS/QCD approach provides a model for the light-front potential which is color-confining and reproduces well the light-hadron spectrum. One also derives via light-front holography a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. The elastic and transition form factors of the pion and the nucleons are found to be well described in this framework. The light-front AdS/QCD holographic approach thus gives a frame-independent first approximation of the color-confining dynamics, spectroscopy, and excitation spectra of relativistic light-quark bound states in QCD.
[ { "created": "Wed, 15 Aug 2012 03:47:53 GMT", "version": "v1" }, { "created": "Thu, 16 Aug 2012 19:25:43 GMT", "version": "v2" } ]
2015-06-11
[ [ "Brodsky", "Stanley J.", "" ], [ "de Teramond", "Guy", "" ] ]
One of the most important nonperturbative methods for solving QCD is quantization at fixed light-front time, \tau = t+z/c -- Dirac's "Front Form". The eigenvalues of the light-front QCD Hamiltonian predict the hadron spectrum and the eigensolutions provide the light-front wavefunctions which describe hadron structure. More generally, we show that the valence Fock-state wavefunctions of the light-front QCD Hamiltonian satisfy a single-variable relativistic equation of motion, analogous to the nonrelativistic radial Schr\"odinger equation, with an effective confining potential U which systematically incorporates the effects of higher quark and gluon Fock states. We outline a method for computing the required potential from first principles in QCD. The holographic mapping of gravity in AdS space to QCD, quantized at fixed light-front time, yields the same light front Schr\"odinger equation; in fact, the soft-wall AdS/QCD approach provides a model for the light-front potential which is color-confining and reproduces well the light-hadron spectrum. One also derives via light-front holography a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. The elastic and transition form factors of the pion and the nucleons are found to be well described in this framework. The light-front AdS/QCD holographic approach thus gives a frame-independent first approximation of the color-confining dynamics, spectroscopy, and excitation spectra of relativistic light-quark bound states in QCD.
hep-ph/9707452
Elizabeth H. Simmons
E.H. Simmons
The Significance of the Heavy Top Quark
10 pages, Talk given at Beyond the Standard Model V, 29 April - 4 May, 1997, Balholm, Norway
null
10.1063/1.54449
BUHEP-97-22
hep-ph
null
Experiment shows that the top quark is far heavier than the other elementary fermions. This finding has stimulated research on theories of electroweak and flavor symmetry breaking that include physics beyond the standard model. Efforts to accommodate a heavy top quark within existing frameworks have revealed constraints on model-building. Other investigations have started from the premise that a large top quark mass could signal a qualitative difference between the top quark and other fermions, perhaps in the form of new interactions peculiar to the top quark. Such new dynamics may also help answer existing questions about electroweak and flavor physics. This talk explores the implications of the heavy top quark in the context of weakly-coupled (e.g. SUSY) and strongly-coupled (e.g. technicolor) theories of electroweak symmetry breaking.
[ { "created": "Thu, 24 Jul 1997 18:14:32 GMT", "version": "v1" } ]
2009-10-30
[ [ "Simmons", "E. H.", "" ] ]
Experiment shows that the top quark is far heavier than the other elementary fermions. This finding has stimulated research on theories of electroweak and flavor symmetry breaking that include physics beyond the standard model. Efforts to accommodate a heavy top quark within existing frameworks have revealed constraints on model-building. Other investigations have started from the premise that a large top quark mass could signal a qualitative difference between the top quark and other fermions, perhaps in the form of new interactions peculiar to the top quark. Such new dynamics may also help answer existing questions about electroweak and flavor physics. This talk explores the implications of the heavy top quark in the context of weakly-coupled (e.g. SUSY) and strongly-coupled (e.g. technicolor) theories of electroweak symmetry breaking.
1901.04266
Wayne de Paula
A. Castro, E. Ydrefors, W. de Paula, T. Frederico, J.H. de Alvarenga Nogueira and P. Maris
The Bethe-Salpeter approach to bound states: from Euclidean to Minkowski space
null
null
10.1088/1742-6596/1291/1/012006
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The challenge to obtain from the Euclidean Bethe--Salpeter amplitude the amplitude in Minkowski is solved by resorting to un-Wick rotating the Euclidean homogeneous integral equation. The results obtained with this new practical method for the amputated Bethe--Salpeter amplitude for a two-boson bound state reveals a rich analytic structure of this amplitude, which can be traced back to the Minkowski space Bethe--Salpeter equation using the Nakanishi integral representation. The method can be extended to small rotation angles bringing the Euclidean solution closer to the Minkowski one and could allow in principle the extraction of the longitudinal parton density functions and momentum distribution amplitude, for example.
[ { "created": "Mon, 14 Jan 2019 12:46:41 GMT", "version": "v1" } ]
2019-10-02
[ [ "Castro", "A.", "" ], [ "Ydrefors", "E.", "" ], [ "de Paula", "W.", "" ], [ "Frederico", "T.", "" ], [ "Nogueira", "J. H. de Alvarenga", "" ], [ "Maris", "P.", "" ] ]
The challenge to obtain from the Euclidean Bethe--Salpeter amplitude the amplitude in Minkowski is solved by resorting to un-Wick rotating the Euclidean homogeneous integral equation. The results obtained with this new practical method for the amputated Bethe--Salpeter amplitude for a two-boson bound state reveals a rich analytic structure of this amplitude, which can be traced back to the Minkowski space Bethe--Salpeter equation using the Nakanishi integral representation. The method can be extended to small rotation angles bringing the Euclidean solution closer to the Minkowski one and could allow in principle the extraction of the longitudinal parton density functions and momentum distribution amplitude, for example.
hep-ph/0102003
Dipankar Chakrabarti
Asmita Mukherjee and Dipankar Chakrabarti
Quark Transversity Distribution in Perturbative QCD: Light-Front Hamiltonian Approach
minor changes in the text, references added
Phys.Lett. B506 (2001) 283-288
10.1016/S0370-2693(01)00364-1
null
hep-ph
null
To resolve the current ambiguity in the splitting function corresponding to the quark transversity distribution $h_1(x)$, we calculate $h_1(x)$ for a dressed quark in light-front Hamiltonian perturbation theory. Our result agrees with the expected form of the splitting function found in the literature and disagrees with the recent calculation in \cite{kuhn}. We emphasize the importance of quark mass in $h_1(x)$ in perturbative QCD and show its connection with a part of $g_T$.
[ { "created": "Thu, 1 Feb 2001 12:01:37 GMT", "version": "v1" }, { "created": "Thu, 15 Feb 2001 06:21:34 GMT", "version": "v2" } ]
2009-11-07
[ [ "Mukherjee", "Asmita", "" ], [ "Chakrabarti", "Dipankar", "" ] ]
To resolve the current ambiguity in the splitting function corresponding to the quark transversity distribution $h_1(x)$, we calculate $h_1(x)$ for a dressed quark in light-front Hamiltonian perturbation theory. Our result agrees with the expected form of the splitting function found in the literature and disagrees with the recent calculation in \cite{kuhn}. We emphasize the importance of quark mass in $h_1(x)$ in perturbative QCD and show its connection with a part of $g_T$.
hep-ph/0107065
Vladimir Galkin
D. Ebert, R. N. Faustov, V. O. Galkin
Form factors of heavy-to-light B decays at large recoil
23 pages, revtex
Phys.Rev.D64:094022,2001
10.1103/PhysRevD.64.094022
HU-EP-01/27, RCNP-Th01018
hep-ph
null
General relations between the form factors of B decays to light mesons are derived using the heavy quark and large recoil expansion. On their basis the complete account of contributions of second order in the ratio of the light meson mass to the large recoil energy is performed. Both ground and excited final meson states are considered. It is shown that most of the known form factor relations remain valid after the inclusion of quadratic mass corrections. The validity of some of such relations requires additional equalities for the helicity amplitudes. It is found that all these relations and equalities are fulfilled in the relativistic quark model based on the quasipotential approach in quantum field theory. The contribution of 1/m_b corrections to the branching fraction of the rare radiative B decay is discussed.
[ { "created": "Fri, 6 Jul 2001 14:33:50 GMT", "version": "v1" } ]
2014-11-17
[ [ "Ebert", "D.", "" ], [ "Faustov", "R. N.", "" ], [ "Galkin", "V. O.", "" ] ]
General relations between the form factors of B decays to light mesons are derived using the heavy quark and large recoil expansion. On their basis the complete account of contributions of second order in the ratio of the light meson mass to the large recoil energy is performed. Both ground and excited final meson states are considered. It is shown that most of the known form factor relations remain valid after the inclusion of quadratic mass corrections. The validity of some of such relations requires additional equalities for the helicity amplitudes. It is found that all these relations and equalities are fulfilled in the relativistic quark model based on the quasipotential approach in quantum field theory. The contribution of 1/m_b corrections to the branching fraction of the rare radiative B decay is discussed.
1412.7143
Vitaly Velizhanin
V.N. Velizhanin
Generalised double-logarithmic equation in QCD
10 pages, 2 figures
null
null
HU-Mathematik-2014-40, HU-EP-14/62
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a generalisation of the double-logarithmic equation for the anomalous dimension of the non-singlet unpolarized twist-2 operators in QCD. Using the known three-loop result, this generalisation allows to predict a small x expansion of the four-loop non-singlet splitting functions in QCD for all powers of logarithms up to the single-logarithm term.
[ { "created": "Mon, 22 Dec 2014 20:49:21 GMT", "version": "v1" }, { "created": "Mon, 12 Jan 2015 18:26:31 GMT", "version": "v2" }, { "created": "Thu, 30 Nov 2017 18:24:19 GMT", "version": "v3" } ]
2017-12-01
[ [ "Velizhanin", "V. N.", "" ] ]
We present a generalisation of the double-logarithmic equation for the anomalous dimension of the non-singlet unpolarized twist-2 operators in QCD. Using the known three-loop result, this generalisation allows to predict a small x expansion of the four-loop non-singlet splitting functions in QCD for all powers of logarithms up to the single-logarithm term.
2104.09923
Mario Reig
Mario Reig
The Stochastic Axiverse
45 pages, 6 figures; v2: references added, accepted for publication in JHEP
JHEP 09 (2021) 207
10.1007/JHEP09(2021)207
IFIC/21-12
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In addition to spectacular signatures such as black hole superradiance and the rotation of CMB polarization, the plenitude of axions appearing in the string axiverse may have potentially dangerous implications. An example is the cosmological overproduction of relic axions and moduli by the misalignment mechanism, more pronounced in regions where the signals mentioned above may be observable, that is for large axion decay constant. In this work, we study the minimal requirements to soften this problem and show that the fundamental requirement is a long period of low-scale inflation. However, in this case, if the inflationary Hubble scale is lower than around $O(100)$ eV, no relic DM axion is produced in the early Universe. Cosmological production of some axions may be activated, via the misalignment mechanism, if their potential minimum changes between inflation and today. As a particular example, we study in detail how the maximal-misalignment mechanism dilutes the effect of dangerous axions and allows the production of axion DM in a controlled way. In this case, the potential of the axion that realises the mechanism shifts by a factor $\Delta\theta=\pi$ between the inflationary epoch and today, and the axion starts to oscillate from the top of its potential. We also show that axions with masses $m_a\sim O(1-100)\, H_0$ realising the maximal-misalignment mechanism generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding problems associated to super-Planckian scales. Finally, we briefly study the basic phenomenological implications of the mechanism and comment on the compatibility of this type of maximally-misaligned quintessence with the swampland criteria.
[ { "created": "Tue, 20 Apr 2021 12:31:51 GMT", "version": "v1" }, { "created": "Sun, 12 Sep 2021 19:36:27 GMT", "version": "v2" } ]
2021-10-05
[ [ "Reig", "Mario", "" ] ]
In addition to spectacular signatures such as black hole superradiance and the rotation of CMB polarization, the plenitude of axions appearing in the string axiverse may have potentially dangerous implications. An example is the cosmological overproduction of relic axions and moduli by the misalignment mechanism, more pronounced in regions where the signals mentioned above may be observable, that is for large axion decay constant. In this work, we study the minimal requirements to soften this problem and show that the fundamental requirement is a long period of low-scale inflation. However, in this case, if the inflationary Hubble scale is lower than around $O(100)$ eV, no relic DM axion is produced in the early Universe. Cosmological production of some axions may be activated, via the misalignment mechanism, if their potential minimum changes between inflation and today. As a particular example, we study in detail how the maximal-misalignment mechanism dilutes the effect of dangerous axions and allows the production of axion DM in a controlled way. In this case, the potential of the axion that realises the mechanism shifts by a factor $\Delta\theta=\pi$ between the inflationary epoch and today, and the axion starts to oscillate from the top of its potential. We also show that axions with masses $m_a\sim O(1-100)\, H_0$ realising the maximal-misalignment mechanism generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding problems associated to super-Planckian scales. Finally, we briefly study the basic phenomenological implications of the mechanism and comment on the compatibility of this type of maximally-misaligned quintessence with the swampland criteria.
hep-ph/9812325
null
Alakabha Datta, Patrick. J. O'Donnell, Sandip Pakvasa and Xinmin Zhang
Flavor Changing processes in Quarkonium Decays
Minor changes in the last section. Latex 22 pages, one figure. To appear in Phys. Rev. D
Phys.Rev. D60 (1999) 014011
10.1103/PhysRevD.60.014011
UTPT-98-17, UH-511-921-98
hep-ph hep-ex
null
We study flavor changing processes $\Upsilon \to B/{\bar B} X_s$ and $J/\psi \to D/{\bar D} X_u$ in the B factories and the Tau-Charm factories. In the standard model, these processes are predicted to be unobservable, so they serve as a probe of the new physics. We first perform a model independent analysis, then examine the predictions of models; such as TopColor models, MSSM with R-parity violation and the two Higgs doublet model; for the branching ratios of $\Upsilon \to B/{\bar B} X_s$ and $J/\psi \to D/{\bar D} X_u$ . We find that these branching ratios could be as large as $10^{-6}$ and $10^{-5}$ in the presence of new physics.
[ { "created": "Thu, 10 Dec 1998 19:41:22 GMT", "version": "v1" }, { "created": "Tue, 23 Mar 1999 19:52:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Datta", "Alakabha", "" ], [ "O'Donnell", "Patrick. J.", "" ], [ "Pakvasa", "Sandip", "" ], [ "Zhang", "Xinmin", "" ] ]
We study flavor changing processes $\Upsilon \to B/{\bar B} X_s$ and $J/\psi \to D/{\bar D} X_u$ in the B factories and the Tau-Charm factories. In the standard model, these processes are predicted to be unobservable, so they serve as a probe of the new physics. We first perform a model independent analysis, then examine the predictions of models; such as TopColor models, MSSM with R-parity violation and the two Higgs doublet model; for the branching ratios of $\Upsilon \to B/{\bar B} X_s$ and $J/\psi \to D/{\bar D} X_u$ . We find that these branching ratios could be as large as $10^{-6}$ and $10^{-5}$ in the presence of new physics.
1212.1662
Jos\'e Francisco Zurita
Jos\'e Zurita
SUSY confronts LHC data
5 pages, 4 figures, PLHC proceeding, typos corrected, references added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The current searches at the LHC have set strong bounds on the masses of gluinos and the squarks of the first and second generation. At the same time, the hints of a Higgs boson at 125 GeV imply some degree of fine-tuning from radiative corrections to the lightest Higgs mass. Moreover, the rate into photons seems to be enhanced with respect to the SM, while the ZZ channel is reduced (albeit the SM is still compatible at the 2-sigma level). In this talk I will review how the previous issues can be addressed. If the stop is about a couple-hundred GeV, the SUSY still remains as a natural solution to the hierarchy problem. I will also show how the MSSM can accommodate a 125 GeV Higgs and also how extensions of the MSSM can alleviate the fine-tuning on the Higgs mass. I will also discuss recent literature, showing how both in the MSSM and its extensions one can find suitable ways to accommodate the measured Higgs rates into photons and Z bosons.
[ { "created": "Fri, 7 Dec 2012 17:25:47 GMT", "version": "v1" }, { "created": "Mon, 17 Dec 2012 11:19:22 GMT", "version": "v2" } ]
2012-12-18
[ [ "Zurita", "José", "" ] ]
The current searches at the LHC have set strong bounds on the masses of gluinos and the squarks of the first and second generation. At the same time, the hints of a Higgs boson at 125 GeV imply some degree of fine-tuning from radiative corrections to the lightest Higgs mass. Moreover, the rate into photons seems to be enhanced with respect to the SM, while the ZZ channel is reduced (albeit the SM is still compatible at the 2-sigma level). In this talk I will review how the previous issues can be addressed. If the stop is about a couple-hundred GeV, the SUSY still remains as a natural solution to the hierarchy problem. I will also show how the MSSM can accommodate a 125 GeV Higgs and also how extensions of the MSSM can alleviate the fine-tuning on the Higgs mass. I will also discuss recent literature, showing how both in the MSSM and its extensions one can find suitable ways to accommodate the measured Higgs rates into photons and Z bosons.
0902.3346
Antonio Vairo
Antonio Vairo
Non-relativistic bound states: the long way back from the Bethe-Salpeter to the Schroedinger equation
Contribution to "Fundamental Interactions - A Memorial Volume for Wolfgang Kummer", D. Grumiller, A. Rebhan, D.V. Vassilevich (eds.); 17 pages, 6 figures; references added
null
10.1142/9789814277839_0002
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review, in a personal perspective, the history of the theory of non-relativistic bound states in QED and QCD from the Bethe-Salpeter equation to the construction of effective field theories.
[ { "created": "Thu, 19 Feb 2009 11:25:26 GMT", "version": "v1" }, { "created": "Mon, 6 Apr 2009 12:48:39 GMT", "version": "v2" } ]
2016-12-21
[ [ "Vairo", "Antonio", "" ] ]
I review, in a personal perspective, the history of the theory of non-relativistic bound states in QED and QCD from the Bethe-Salpeter equation to the construction of effective field theories.
1304.1194
Ming Gong
M. Gong, A. Alexandru, Y. Chen, T. Doi, S.J. Dong, T. Draper, W. Freeman, M. Glatzmaier, A. Li, K.F. Liu, Z. Liu
Strangeness and charmness content of nucleon from overlap fermions on 2+1-flavor domain-wall fermion configurations
34 pages, 18 figures; correct typos and minor updates; Figures updated, final version published in Phys. Rev. D 88, 014503 (2013)
Phys. Rev. D 88, 014503 (2013)
10.1103/PhysRevD.88.014503
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a calculation of the strangeness and charmness contents <N|\bar{s}s|N> and <N|\bar{c}c|N> of the nucleon from dynamical lattice QCD with 2+1 flavors. The calculation is performed with overlap valence quarks on 2+1-flavor domain-wall fermion gauge configurations. The configurations are generated by the RBC collaboration on a 24^3*64 lattice with sea quark mass am_l=0.005, am_s=0.04, and inverse lattice spacing a^{-1}=1.73GeV. Both actions have chiral symmetry which is essential in avoiding contamination due to the operator mixing with other flavors. Nucleon propagator and the quark loops are both computed with stochastic grid sources, while low-mode substitution and low-mode averaging methods are used respectively which substantially improve the signal to noise ratio. We obtain the strangeness matrix element f_{T_{s}} = m_s <N|\bar{s}s|N> / M_N = 0.0334(62), and the charmness content f_{T_{c}} = m_c <N|\bar{c}c|N> / M_N = 0.094(31) which is resolved from zero by 3\sigma precision for the first time.
[ { "created": "Wed, 3 Apr 2013 21:18:26 GMT", "version": "v1" }, { "created": "Thu, 16 May 2013 18:27:29 GMT", "version": "v2" }, { "created": "Mon, 10 Jun 2013 05:58:48 GMT", "version": "v3" }, { "created": "Sat, 17 Aug 2013 22:34:52 GMT", "version": "v4" } ]
2013-08-20
[ [ "Gong", "M.", "" ], [ "Alexandru", "A.", "" ], [ "Chen", "Y.", "" ], [ "Doi", "T.", "" ], [ "Dong", "S. J.", "" ], [ "Draper", "T.", "" ], [ "Freeman", "W.", "" ], [ "Glatzmaier", "M.", "" ], [ "Li", "A.", "" ], [ "Liu", "K. F.", "" ], [ "Liu", "Z.", "" ] ]
We present a calculation of the strangeness and charmness contents <N|\bar{s}s|N> and <N|\bar{c}c|N> of the nucleon from dynamical lattice QCD with 2+1 flavors. The calculation is performed with overlap valence quarks on 2+1-flavor domain-wall fermion gauge configurations. The configurations are generated by the RBC collaboration on a 24^3*64 lattice with sea quark mass am_l=0.005, am_s=0.04, and inverse lattice spacing a^{-1}=1.73GeV. Both actions have chiral symmetry which is essential in avoiding contamination due to the operator mixing with other flavors. Nucleon propagator and the quark loops are both computed with stochastic grid sources, while low-mode substitution and low-mode averaging methods are used respectively which substantially improve the signal to noise ratio. We obtain the strangeness matrix element f_{T_{s}} = m_s <N|\bar{s}s|N> / M_N = 0.0334(62), and the charmness content f_{T_{c}} = m_c <N|\bar{c}c|N> / M_N = 0.094(31) which is resolved from zero by 3\sigma precision for the first time.
1702.02698
Wei Chao
Wei Chao, Huai-Ke Guo, Jing Shu
Gravitational Wave Signals of Electroweak Phase Transition Triggered by Dark Matter
9 pages, 4 figures; more references added
null
10.1088/1475-7516/2017/09/009
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study in this work a scenario that the universe undergoes a two step phase transition with the first step happened to the dark matter sector and the second step being the transition between the dark matter and the electroweak vacuums, where the barrier between the two vacuums, that is necessary for a strongly first order electroweak phase transition (EWPT) as required by the electroweak baryogenesis mechanism, arises at the tree-level. We illustrate this idea by working with the standard model (SM) augmented by a scalar singlet dark matter and an extra scalar singlet which mixes with the SM Higgs boson. We study the conditions for such pattern of phase transition to occur and especially for the strongly first order EWPT to take place, as well as its compatibility with the basic requirements of a successful dark matter, such as observed relic density and constraints of direct detections. We further explore the discovery possibility of this pattern EWPT by searching for the gravitational waves generated during this process in spaced based interferometer, by showing a representative benchmark point of the parameter space that the generated gravitational waves fall within the sensitivity of eLISA, DECIGO and BBO.
[ { "created": "Thu, 9 Feb 2017 04:22:43 GMT", "version": "v1" }, { "created": "Tue, 14 Feb 2017 07:55:12 GMT", "version": "v2" } ]
2017-09-13
[ [ "Chao", "Wei", "" ], [ "Guo", "Huai-Ke", "" ], [ "Shu", "Jing", "" ] ]
We study in this work a scenario that the universe undergoes a two step phase transition with the first step happened to the dark matter sector and the second step being the transition between the dark matter and the electroweak vacuums, where the barrier between the two vacuums, that is necessary for a strongly first order electroweak phase transition (EWPT) as required by the electroweak baryogenesis mechanism, arises at the tree-level. We illustrate this idea by working with the standard model (SM) augmented by a scalar singlet dark matter and an extra scalar singlet which mixes with the SM Higgs boson. We study the conditions for such pattern of phase transition to occur and especially for the strongly first order EWPT to take place, as well as its compatibility with the basic requirements of a successful dark matter, such as observed relic density and constraints of direct detections. We further explore the discovery possibility of this pattern EWPT by searching for the gravitational waves generated during this process in spaced based interferometer, by showing a representative benchmark point of the parameter space that the generated gravitational waves fall within the sensitivity of eLISA, DECIGO and BBO.
0806.1049
David Tucker-Smith
Lisa Randall and David Tucker-Smith
Dijet Searches for Supersymmetry at the LHC
null
Phys.Rev.Lett.101:221803,2008
10.1103/PhysRevLett.101.221803
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present several strategies for searching for supersymmetry in dijet channels that do not explicitly invoke missing energy. Preliminary investigations suggest that signal-to-background ratios of at least 4--5 should be achievable at the LHC, with discovery possible for squarks as heavy as ~ 1.7 TeV.
[ { "created": "Thu, 5 Jun 2008 20:12:30 GMT", "version": "v1" } ]
2008-12-18
[ [ "Randall", "Lisa", "" ], [ "Tucker-Smith", "David", "" ] ]
We present several strategies for searching for supersymmetry in dijet channels that do not explicitly invoke missing energy. Preliminary investigations suggest that signal-to-background ratios of at least 4--5 should be achievable at the LHC, with discovery possible for squarks as heavy as ~ 1.7 TeV.
hep-ph/9912346
Akaki Rusetsky
A. Rusetsky (Bern University, JINR, Dubna and HEPI, Tbilisi University)
Report of Working Group on Electromagnetic Corrections
11 pages. Talk given at ``8th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU99)'', Zuoz, Switzerland, August 15-20, 1999
PiN Newslett.15:176-180,1999
null
BUTP-99/30
hep-ph
null
The talks delivered by M. Knecht, H. Neufeld, V.E. Lyubovitskij, A. Rusetsky and J. Soto during the session of the working group of electromagnetic corrections to hadronic processes at the Eight International Symposium MENU99, cover a wide range of problems. In particular, those include: construction of the effective Lagrangians that then are used for the evaluation of electromagnetic corrections to the decays of K mesons; evaluation of some of the low-energy constants in these Lagrangians, using sum rules and the large-N_c arguments; complete calculations of electromagnetic corrections to the pi pi scattering amplitude at O(e^2p^2); the general theory of electromagnetic bound states of hadrons in the Standard Model.
[ { "created": "Wed, 15 Dec 1999 09:06:16 GMT", "version": "v1" } ]
2011-04-15
[ [ "Rusetsky", "A.", "", "Bern University, JINR, Dubna and HEPI, Tbilisi\n University" ] ]
The talks delivered by M. Knecht, H. Neufeld, V.E. Lyubovitskij, A. Rusetsky and J. Soto during the session of the working group of electromagnetic corrections to hadronic processes at the Eight International Symposium MENU99, cover a wide range of problems. In particular, those include: construction of the effective Lagrangians that then are used for the evaluation of electromagnetic corrections to the decays of K mesons; evaluation of some of the low-energy constants in these Lagrangians, using sum rules and the large-N_c arguments; complete calculations of electromagnetic corrections to the pi pi scattering amplitude at O(e^2p^2); the general theory of electromagnetic bound states of hadrons in the Standard Model.
0802.3615
Masayasu Harada
Masayasu Harada (Nagoya U.) and Chihiro Sasaki (TU Munich)
Dilepton Production from Dropping rho in the Vector Manifestation
Contribution to the proceedings of ``Chiral Symmetry in Hadron and Nuclear Physics (Chiral 07)'' (November 13-16, 2007, Osaka University, Japan)
Mod.Phys.Lett.A23:2405-2408,2008
10.1142/S0217732308029484
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this write-up we summarize the main result of our analysis on the thermal dilepton production rate from the dropping rho based on the vector manifestation (VM). In the analysis, we showed that the effect of the strong violation of the vector dominance (VD) predicted by the VM, substantially suppresses the dilepton production rate compared with the one predicted by assuming the VD together with the dropping rho.
[ { "created": "Mon, 25 Feb 2008 12:46:34 GMT", "version": "v1" } ]
2008-11-26
[ [ "Harada", "Masayasu", "", "Nagoya U." ], [ "Sasaki", "Chihiro", "", "TU Munich" ] ]
In this write-up we summarize the main result of our analysis on the thermal dilepton production rate from the dropping rho based on the vector manifestation (VM). In the analysis, we showed that the effect of the strong violation of the vector dominance (VD) predicted by the VM, substantially suppresses the dilepton production rate compared with the one predicted by assuming the VD together with the dropping rho.
hep-ph/9711444
null
R. N. Mohapatra
Neutrino Physics in a Muon collider
Some parts of the text changed; major conclusions unchanged
AIP Conf.Proc.435:358-369,1998
10.1063/1.56199
null
hep-ph
null
A muon collider is expected to produce a high intensity neutrino beam which is an admixture of either $\nu_{\mu}+\bar{\nu_e}$ or $\bar{\nu}_{\mu} +\nu_e$ which can can be directed to underground detectors far away from the source. It will not only allow a probe of the $\nu_e-\nu_{\mu}$ as well as $\nu_{\mu}-\nu_{\tau}$ oscillations in a range of mixing angle and $\Delta m^2$ not probed heretofore but it will also provide information about the mixing angle $\theta_{e\tau}$ for a wide range of $\Delta m^2_{\nu_e\nu_{\tau}}$ from $10^{-4}$ eV$^2$ to $10^{-1}$ eV$^2$ which cannot be obtained from any other existing or proposed machine. One can also search for violations of Lorentz invariance and deviations from equivalence principle for neutrinos at a level which is three to four orders of magnitude more sensitive than possible at the moment. This will test for instance some unorthodox suggestions to understand both solar and atmospheric neutrinos using a single mass difference -squared between the $\nu_e$ and $\nu_{\mu}$. It can also test various proposed models neutrino masses and mixings to understand existing neutrino data.
[ { "created": "Mon, 24 Nov 1997 18:00:24 GMT", "version": "v1" }, { "created": "Fri, 19 Dec 1997 14:58:52 GMT", "version": "v2" } ]
2011-07-19
[ [ "Mohapatra", "R. N.", "" ] ]
A muon collider is expected to produce a high intensity neutrino beam which is an admixture of either $\nu_{\mu}+\bar{\nu_e}$ or $\bar{\nu}_{\mu} +\nu_e$ which can can be directed to underground detectors far away from the source. It will not only allow a probe of the $\nu_e-\nu_{\mu}$ as well as $\nu_{\mu}-\nu_{\tau}$ oscillations in a range of mixing angle and $\Delta m^2$ not probed heretofore but it will also provide information about the mixing angle $\theta_{e\tau}$ for a wide range of $\Delta m^2_{\nu_e\nu_{\tau}}$ from $10^{-4}$ eV$^2$ to $10^{-1}$ eV$^2$ which cannot be obtained from any other existing or proposed machine. One can also search for violations of Lorentz invariance and deviations from equivalence principle for neutrinos at a level which is three to four orders of magnitude more sensitive than possible at the moment. This will test for instance some unorthodox suggestions to understand both solar and atmospheric neutrinos using a single mass difference -squared between the $\nu_e$ and $\nu_{\mu}$. It can also test various proposed models neutrino masses and mixings to understand existing neutrino data.
1605.09502
Jesse Liu
Alan Barr and Jesse Liu
First interpretation of 13 TeV supersymmetry searches in the pMSSM
5 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The combined constraints from six early Run 2 ATLAS searches for supersymmetry are interpreted in the phenomenological minimal supersymmetric extension to the Standard Model (pMSSM). Each of the searches was based on proton-proton collision data recorded in 2015 at $\sqrt{s} =13$ TeV with 3.2 fb$^{-1}$ of integrated luminosity. Sensitivity to squarks of the first two generations and gluinos are evaluated using fast detector simulation. Results are presented in the 19-parameter R-parity conserving pMSSM with the lightest supersymmetric particle (LSP) being the neutralino. Considering 181.8k points that survived Run 1 constraints, 15.7% are excluded at 95% confidence level. Of those satisfying these Run 2 constraints, 0.5% (1.0%) have sub-TeV gluinos (sub-500 GeV squarks), the lightest of which has a mass of 757 GeV (293 GeV) with a 689 GeV (217 GeV) LSP.
[ { "created": "Tue, 31 May 2016 05:48:32 GMT", "version": "v1" } ]
2016-06-01
[ [ "Barr", "Alan", "" ], [ "Liu", "Jesse", "" ] ]
The combined constraints from six early Run 2 ATLAS searches for supersymmetry are interpreted in the phenomenological minimal supersymmetric extension to the Standard Model (pMSSM). Each of the searches was based on proton-proton collision data recorded in 2015 at $\sqrt{s} =13$ TeV with 3.2 fb$^{-1}$ of integrated luminosity. Sensitivity to squarks of the first two generations and gluinos are evaluated using fast detector simulation. Results are presented in the 19-parameter R-parity conserving pMSSM with the lightest supersymmetric particle (LSP) being the neutralino. Considering 181.8k points that survived Run 1 constraints, 15.7% are excluded at 95% confidence level. Of those satisfying these Run 2 constraints, 0.5% (1.0%) have sub-TeV gluinos (sub-500 GeV squarks), the lightest of which has a mass of 757 GeV (293 GeV) with a 689 GeV (217 GeV) LSP.
1812.08163
Javier Virto
S\'ebastien Descotes-Genon, Adam Falkowski, Marco Fedele, Mart\'in Gonz\'alez-Alonso, Javier Virto
The CKM parameters in the SMEFT
36 pages. Version published in JHEP
JHEP 1905, 172 (2019)
10.1007/JHEP05(2019)172
LPT Orsay 18-92, CERN-TH-2018-276, TUM-HEP-1178/18, MIT-CTP/5081, NIOBE-2018-01
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix from flavour observables can be affected by physics beyond the Standard Model (SM). We provide a general roadmap to take this into account, which we apply to the case of the Standard Model Effective Field Theory (SMEFT). We choose a set of four input observables that determine the four Wolfenstein parameters, and discuss how the effects of dimension-six operators can be included in their definition. We provide numerical values and confidence intervals for the CKM parameters, and compare them with the results of CKM fits obtained in the SM context. Our approach allows one to perform general SMEFT analyses in a consistent fashion, independently of any assumptions about the way new physics affects flavour observables. We discuss a few examples illustrating how our approach can be implemented in practice.
[ { "created": "Wed, 19 Dec 2018 18:59:56 GMT", "version": "v1" }, { "created": "Wed, 13 Mar 2019 01:37:40 GMT", "version": "v2" }, { "created": "Tue, 4 Jun 2019 14:47:51 GMT", "version": "v3" } ]
2019-06-05
[ [ "Descotes-Genon", "Sébastien", "" ], [ "Falkowski", "Adam", "" ], [ "Fedele", "Marco", "" ], [ "González-Alonso", "Martín", "" ], [ "Virto", "Javier", "" ] ]
The extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix from flavour observables can be affected by physics beyond the Standard Model (SM). We provide a general roadmap to take this into account, which we apply to the case of the Standard Model Effective Field Theory (SMEFT). We choose a set of four input observables that determine the four Wolfenstein parameters, and discuss how the effects of dimension-six operators can be included in their definition. We provide numerical values and confidence intervals for the CKM parameters, and compare them with the results of CKM fits obtained in the SM context. Our approach allows one to perform general SMEFT analyses in a consistent fashion, independently of any assumptions about the way new physics affects flavour observables. We discuss a few examples illustrating how our approach can be implemented in practice.
hep-ph/9309333
null
L.Xiong and E.Shuryak
Gluon multiplication in high energy heavy ion collisions
28 pages (4 Figures not included here may be requested from the authors)
Phys.Rev.C49:2203-2211,1994
10.1103/PhysRevC.49.2203
SUNY-NTG-93-24
hep-ph nucl-th
null
Hot gluons are the dominant components of the QCD plasma to be formed in future high energy heavy ion experiments. In this paper we study the elementary processes in the plasma medium for gluon multiplication based on all orders of the tree-diagrams in perturbative QCD. When applying to the chemical equilibration in the expanding system, we found that the gluons reaches chemical equilibrium well within its plasma phase. The inclusion of all the next-to-leading order processes makes the equilibration considerably faster than the simple $gg\leftrightarrow ggg$ one considered previously.
[ { "created": "Wed, 29 Sep 1993 21:16:55 GMT", "version": "v1" } ]
2008-11-26
[ [ "Xiong", "L.", "" ], [ "Shuryak", "E.", "" ] ]
Hot gluons are the dominant components of the QCD plasma to be formed in future high energy heavy ion experiments. In this paper we study the elementary processes in the plasma medium for gluon multiplication based on all orders of the tree-diagrams in perturbative QCD. When applying to the chemical equilibration in the expanding system, we found that the gluons reaches chemical equilibrium well within its plasma phase. The inclusion of all the next-to-leading order processes makes the equilibration considerably faster than the simple $gg\leftrightarrow ggg$ one considered previously.
hep-ph/9712405
Dr Tony Williams
A.G. Williams (U. of Adelaide)
New results in vector meson dominance and rho meson physics
16 pages, 1 figures, to appear in the Proceedings of the APCTP Workshop on Astro-Hadron Physics, ``Properties of Hadrons in Matter'', Seoul, 25-31 October, 1997. *Minor typing and reference corrections.*
null
null
ADP-97-54/T280
hep-ph
null
Recent results by Benayoun et al. comparing the predictions of a range of existing models based on the Vector Meson Dominance hypothesis are summarized and discussed. These are compared with data on e+ e- -> pi+ pi- and e+ e- -> mu+ mu- cross-sections and the phase and near-threshold behavior of the timelike pion form factor, with the aim of determining which (if any) of these models is capable of providing an accurate representation of the full range of experimental data. We find that, of the models considered, only that proposed by Bando et al. is able to consistently account for all information, provided one allows its parameter "a" to vary from the usual value of 2 to 2.4. Our fit with the Bando model gives a point-like coupling gamma pi+ pi- of magnitude approximately -e/6, while the common formulation of VMD excludes such a term. The resulting values for the rho mass and pi+ pi- and e+ e- partial widths as well as the branching ratio for the decay omega -> pi+ pi- obtained within the context of this model are consistent with previous results.
[ { "created": "Wed, 17 Dec 1997 05:58:04 GMT", "version": "v1" }, { "created": "Wed, 24 Dec 1997 01:18:56 GMT", "version": "v2" } ]
2007-05-23
[ [ "Williams", "A. G.", "", "U. of Adelaide" ] ]
Recent results by Benayoun et al. comparing the predictions of a range of existing models based on the Vector Meson Dominance hypothesis are summarized and discussed. These are compared with data on e+ e- -> pi+ pi- and e+ e- -> mu+ mu- cross-sections and the phase and near-threshold behavior of the timelike pion form factor, with the aim of determining which (if any) of these models is capable of providing an accurate representation of the full range of experimental data. We find that, of the models considered, only that proposed by Bando et al. is able to consistently account for all information, provided one allows its parameter "a" to vary from the usual value of 2 to 2.4. Our fit with the Bando model gives a point-like coupling gamma pi+ pi- of magnitude approximately -e/6, while the common formulation of VMD excludes such a term. The resulting values for the rho mass and pi+ pi- and e+ e- partial widths as well as the branching ratio for the decay omega -> pi+ pi- obtained within the context of this model are consistent with previous results.
hep-ph/0405267
Spencer Chang
Spencer Chang, Can Kilic, Rakhi Mahbubani
The New Fat Higgs: Slimmer and More Attractive
14 pages and 2 figures. Added references and updated argument about constraints from reheating temperature
Phys.Rev. D71 (2005) 015003
10.1103/PhysRevD.71.015003
HUTP-04/A025
hep-ph hep-th
null
In this paper we increase the MSSM tree level higgs mass bound to a value that is naturally larger than the LEP-II search constraint by adding to the superpotential a $\lambda S H_{u}H_{d}$ term, as in the NMSSM, and UV completing with new strong dynamics {\it before} $\lambda$ becomes non-perturbative. Unlike other models of this type the higgs fields remain elementary, alleviating the supersymmetric fine-tuning problem while maintaining unification in a natural way.
[ { "created": "Wed, 26 May 2004 19:32:17 GMT", "version": "v1" }, { "created": "Thu, 19 May 2005 19:16:31 GMT", "version": "v2" } ]
2009-11-10
[ [ "Chang", "Spencer", "" ], [ "Kilic", "Can", "" ], [ "Mahbubani", "Rakhi", "" ] ]
In this paper we increase the MSSM tree level higgs mass bound to a value that is naturally larger than the LEP-II search constraint by adding to the superpotential a $\lambda S H_{u}H_{d}$ term, as in the NMSSM, and UV completing with new strong dynamics {\it before} $\lambda$ becomes non-perturbative. Unlike other models of this type the higgs fields remain elementary, alleviating the supersymmetric fine-tuning problem while maintaining unification in a natural way.
hep-ph/9402203
Glennys R. Farrar
M. B. Cakir and G. R. Farrar
Radiative Decay of Vector Quarkonium: Constraints on Glueballs and Light Gluinos
36pp (inc figs),RU-94-04. (Replaces original which didn't latex correctly and didn't have figures.)
Phys.Rev.D50:3268-3278,1994
10.1103/PhysRevD.50.3268
null
hep-ph
null
Given a resonance of known mass, width, and J^{PC}, we can determine its gluonic branching fraction, b(R->gg), from data on its production in radiative vector quarkonium decay, V -> gamma+R. For most resonances b(R->gg) is found to be O(10%), consistent with being q-qbar states, but we find that both pseudoscalars observed in the 1440 MeV region have b(R->gg) ~ 1/2 - 1, and b(f_0^{++}->gg) ~ 1/2. As data improves, b(R->gg) should be a useful discriminator between q-qbar and gluonic states and may permit quantitative determination of the extent to which a particular resonance is a mixture of glueball and q-qbar. We also examine the regime of validity of pQCD for predicting the rate of V -> gamma+eta_gluino, the ``extra'' pseudoscalar bound state which would exist if there were light gluinos. From the CUSB limit on peaks in Upsilon -> gamma X, the mass range 3 GeV < m(eta_gluino) < 7 GeV can be excluded. An experiment must be significantly more sensitive to exclude an eta_gluino lighter than this.
[ { "created": "Tue, 1 Feb 1994 23:59:10 GMT", "version": "v1" }, { "created": "Fri, 4 Feb 1994 04:03:44 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cakir", "M. B.", "" ], [ "Farrar", "G. R.", "" ] ]
Given a resonance of known mass, width, and J^{PC}, we can determine its gluonic branching fraction, b(R->gg), from data on its production in radiative vector quarkonium decay, V -> gamma+R. For most resonances b(R->gg) is found to be O(10%), consistent with being q-qbar states, but we find that both pseudoscalars observed in the 1440 MeV region have b(R->gg) ~ 1/2 - 1, and b(f_0^{++}->gg) ~ 1/2. As data improves, b(R->gg) should be a useful discriminator between q-qbar and gluonic states and may permit quantitative determination of the extent to which a particular resonance is a mixture of glueball and q-qbar. We also examine the regime of validity of pQCD for predicting the rate of V -> gamma+eta_gluino, the ``extra'' pseudoscalar bound state which would exist if there were light gluinos. From the CUSB limit on peaks in Upsilon -> gamma X, the mass range 3 GeV < m(eta_gluino) < 7 GeV can be excluded. An experiment must be significantly more sensitive to exclude an eta_gluino lighter than this.
0711.4295
Junegone Chay
Junegone Chay
Transverse-momentum-dependent parton distribution function in soft-collinear effective theory
25 pages, 6 figures, added references
null
null
MIT-CTP 3904
hep-ph
null
Transverse-momentum-dependent parton distribution functions are analyzed in semi-inclusive deep inelastic scattering at low transverse momentum using soft-collinear effective theory. The transverse-momentum-dependent parton distribution functions are defined on the lightcone without distorting the lightcone path nor adding additional soft Wilson lines. In this approach, the comparison between the integrated and unintegrated parton distribution functions becomes transparent. The procedure of computing radiative corrections in dimensional regularization is explained in detail, and the divergence, which is a product of infrared and ultraviolet divergence, is cancelled. The renormalization group equation for the transverse-momentum-dependent parton distribution functions is derived. It depends only on the relevant physical quantities and exhibits a nontrivial scaling behavior because the longitudinal momentum fraction and the transverse momentum are coupled in the renormalization group equation.
[ { "created": "Tue, 27 Nov 2007 16:30:02 GMT", "version": "v1" }, { "created": "Thu, 29 Nov 2007 19:30:48 GMT", "version": "v2" } ]
2007-11-29
[ [ "Chay", "Junegone", "" ] ]
Transverse-momentum-dependent parton distribution functions are analyzed in semi-inclusive deep inelastic scattering at low transverse momentum using soft-collinear effective theory. The transverse-momentum-dependent parton distribution functions are defined on the lightcone without distorting the lightcone path nor adding additional soft Wilson lines. In this approach, the comparison between the integrated and unintegrated parton distribution functions becomes transparent. The procedure of computing radiative corrections in dimensional regularization is explained in detail, and the divergence, which is a product of infrared and ultraviolet divergence, is cancelled. The renormalization group equation for the transverse-momentum-dependent parton distribution functions is derived. It depends only on the relevant physical quantities and exhibits a nontrivial scaling behavior because the longitudinal momentum fraction and the transverse momentum are coupled in the renormalization group equation.
hep-ph/9408403
Luc Marleau
B. Dion, L. Marleau and G. Simon
Skyrmions from a Born-Infeld Action
11 pages, 4 figures (not included), revtex v3, LAVAL-PHY-11-94
Phys.Rev. D53 (1996) 1542-1547
10.1103/PhysRevD.53.1542
null
hep-ph
null
We consider a geometrically motivated Skyrme model based on a general covariant kinetic term proposed originally by Born and Infeld. We introduce this new term by generalizing the Born-Infeld action to a non-abelian $SU(2)$ gauge theory and by using the hidden gauge symmetry formalism. The static properties of the Skyrmion are then analyzed and compared with other Skyrme-like models.
[ { "created": "Wed, 31 Aug 1994 07:32:21 GMT", "version": "v1" } ]
2009-10-28
[ [ "Dion", "B.", "" ], [ "Marleau", "L.", "" ], [ "Simon", "G.", "" ] ]
We consider a geometrically motivated Skyrme model based on a general covariant kinetic term proposed originally by Born and Infeld. We introduce this new term by generalizing the Born-Infeld action to a non-abelian $SU(2)$ gauge theory and by using the hidden gauge symmetry formalism. The static properties of the Skyrmion are then analyzed and compared with other Skyrme-like models.
1309.3389
Bernd Kniehl
Paolo Bolzoni, Bernd A. Kniehl, Gustav Kramer
Inclusive J/psi and psi(2S) production from b-hadron decay in p anti-p and pp collisions
13 pages, 2 figures; comparison with approximative evaluation included, discussion enhanced, references added; accepted for publication in Phys. Rev. D
null
10.1103/PhysRevD.88.074035
DESY 13-159
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the inclusive production of J/psi and psi(2S) mesons originating from the decays of bottom-flavored hadrons produced in p anti-p collisions at the Fermilab Tevatron and in pp collisions at the CERN LHC. We work at next-to-leading order in the general-mass variable-flavor-number scheme (GM-VFNS) implemented with nonperturbative fragmentation functions fitted to e^+e^- data of inclusive b-hadron production exploiting their universality. The three-momentum distributions of the charmonia used were extracted from B-decay data in the framework of nonrelativistic-QCD factorization. Comparing the theoretical predictions thus obtained with transverse-momentum distributions measured by the CDF II, ALICE, ATLAS, CMS, and LHCb Collaborations, we find excellent overall agreement as for both absolute normalization and lineshape, which provides a nontrivial test of the GM-VFNS over wide ranges of center-of-mass energy, transverse momentum, and rapidity.
[ { "created": "Fri, 13 Sep 2013 08:18:32 GMT", "version": "v1" }, { "created": "Fri, 18 Oct 2013 20:29:07 GMT", "version": "v2" } ]
2015-06-17
[ [ "Bolzoni", "Paolo", "" ], [ "Kniehl", "Bernd A.", "" ], [ "Kramer", "Gustav", "" ] ]
We study the inclusive production of J/psi and psi(2S) mesons originating from the decays of bottom-flavored hadrons produced in p anti-p collisions at the Fermilab Tevatron and in pp collisions at the CERN LHC. We work at next-to-leading order in the general-mass variable-flavor-number scheme (GM-VFNS) implemented with nonperturbative fragmentation functions fitted to e^+e^- data of inclusive b-hadron production exploiting their universality. The three-momentum distributions of the charmonia used were extracted from B-decay data in the framework of nonrelativistic-QCD factorization. Comparing the theoretical predictions thus obtained with transverse-momentum distributions measured by the CDF II, ALICE, ATLAS, CMS, and LHCb Collaborations, we find excellent overall agreement as for both absolute normalization and lineshape, which provides a nontrivial test of the GM-VFNS over wide ranges of center-of-mass energy, transverse momentum, and rapidity.
1010.1635
Thorsten Renk
Thorsten Renk, Hannu Holopainen, Ulrich Heinz and Chun Shen
A systematic comparison of jet quenching in different fluid-dynamical models
17 pages, 11 figures
Phys.Rev.C83:014910,2011
10.1103/PhysRevC.83.014910
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Comparing four different (ideal and viscous) hydrodynamic models for the evolution of the medium created in 200 AGeV Au-Au collisions, combined with two different models for the path length dependence of parton energy loss, we study the effects of jet quenching on the emission-angle dependence of the nuclear suppression factor R_AA(phi) and the away-side per trigger yield I_AA(phi). Each hydrodynamic model was tuned to provide a reasonable description of the single-particle transverse momentum spectra for all collision centralities, and the energy loss models were adjusted to yield the same pion nuclear suppression factor in central Au-Au collisions. We find that the experimentally measured in-plane vs. out-of-plane spread in R_AA(phi) is better reproduced by models that shift the weight of the parton energy loss to later times along its path. Among the models studied here, this is best achieved by energy loss models that suppress energy loss at early times, combined with hydrodynamic models that delay the dilution of the medium density due to hydrodynamic expansion by viscous heating. We were unable to identify a clear tomographic benefit of a measurement of I_AA(phi) over that of R_AA(phi).
[ { "created": "Fri, 8 Oct 2010 09:28:34 GMT", "version": "v1" } ]
2011-02-28
[ [ "Renk", "Thorsten", "" ], [ "Holopainen", "Hannu", "" ], [ "Heinz", "Ulrich", "" ], [ "Shen", "Chun", "" ] ]
Comparing four different (ideal and viscous) hydrodynamic models for the evolution of the medium created in 200 AGeV Au-Au collisions, combined with two different models for the path length dependence of parton energy loss, we study the effects of jet quenching on the emission-angle dependence of the nuclear suppression factor R_AA(phi) and the away-side per trigger yield I_AA(phi). Each hydrodynamic model was tuned to provide a reasonable description of the single-particle transverse momentum spectra for all collision centralities, and the energy loss models were adjusted to yield the same pion nuclear suppression factor in central Au-Au collisions. We find that the experimentally measured in-plane vs. out-of-plane spread in R_AA(phi) is better reproduced by models that shift the weight of the parton energy loss to later times along its path. Among the models studied here, this is best achieved by energy loss models that suppress energy loss at early times, combined with hydrodynamic models that delay the dilution of the medium density due to hydrodynamic expansion by viscous heating. We were unable to identify a clear tomographic benefit of a measurement of I_AA(phi) over that of R_AA(phi).
hep-ph/9902265
Kai Gallmeister
K. Gallmeister, B. Kaempfer, O.P. Pavlenko
Dileptons and Charm & Bottom in Relativistic Heavy-Ion Collisions
8 LaTeX pages including eps figures, contribution to the 37th International Winter Meeting on Nuclear Physics, Bormio, Jan 25-29, 1999
null
null
null
hep-ph
null
We study the prospects to get information about the early and hot stages of deconfined matter produced in relativistic heavy-ion collisions by analyzing dilepton and single-lepton spectra. Energy losses of heavy quarks in deconfined matter and thermalization effects in hadron matter and their influence on lepton spectra are considered.
[ { "created": "Mon, 8 Feb 1999 12:50:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gallmeister", "K.", "" ], [ "Kaempfer", "B.", "" ], [ "Pavlenko", "O. P.", "" ] ]
We study the prospects to get information about the early and hot stages of deconfined matter produced in relativistic heavy-ion collisions by analyzing dilepton and single-lepton spectra. Energy losses of heavy quarks in deconfined matter and thermalization effects in hadron matter and their influence on lepton spectra are considered.
2203.08270
Scott Snyder
Scott Snyder (1), Christian Weber (1), Danyi Zhang (2) ((1) Brookhaven National Laboratory, (2) Institute of High Energy Physics, Beijing)
Prospects for searches for Higgs boson decays to dark photons at the ILC
20 pages, 6 figures. Submitted to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021)
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
An interesting model of dark matter involves a hidden sector decoupled from Standard Model (SM) fields except for some portal interaction. A concrete realization of this is the Hidden Abelian Higgs Model, which gives rise to decays of the SM Higgs boson into a pair of new bosons, called $Z_{\mathrm{d}}$ or dark photons. This note explores prospects for the search for such dark photons at the ILC with $\sqrt{s}=250$ GeV, where the dark photons decay promptly. For the $H\rightarrow Z_{\mathrm{d}}Z_{\mathrm{d}}\rightarrow 4\ell$ ($\ell = e,\mu$) final state, it follows closely recent similar searches at the LHC, while for the $2\ell2j$ and $4j$ final states a multivariate analysis approach is used. This study has not been approved by the SiD consortium.
[ { "created": "Tue, 15 Mar 2022 21:43:31 GMT", "version": "v1" } ]
2022-03-17
[ [ "Snyder", "Scott", "" ], [ "Weber", "Christian", "" ], [ "Zhang", "Danyi", "" ] ]
An interesting model of dark matter involves a hidden sector decoupled from Standard Model (SM) fields except for some portal interaction. A concrete realization of this is the Hidden Abelian Higgs Model, which gives rise to decays of the SM Higgs boson into a pair of new bosons, called $Z_{\mathrm{d}}$ or dark photons. This note explores prospects for the search for such dark photons at the ILC with $\sqrt{s}=250$ GeV, where the dark photons decay promptly. For the $H\rightarrow Z_{\mathrm{d}}Z_{\mathrm{d}}\rightarrow 4\ell$ ($\ell = e,\mu$) final state, it follows closely recent similar searches at the LHC, while for the $2\ell2j$ and $4j$ final states a multivariate analysis approach is used. This study has not been approved by the SiD consortium.