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1211.7209
Jure Drobnak
Jure Drobnak
Top Decays in the Standard Model and Beyond
Proceedings of CKM 2012, the 7th International Workshop on the CKM Unitarity Triangle, University of Cincinnati, USA, 28 September - 2 October 2012
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings we explore the possibility of new physics manifesting itself in rare top quark decays. In particular, we adopt an effective theory description of FCNC t -> q V top quark decays and possible deviations from the SM form of tWb vertices which would affect the helicity fractions of the W boson produced in the main decay channel of top quark.
[ { "created": "Fri, 30 Nov 2012 10:50:52 GMT", "version": "v1" } ]
2012-12-03
[ [ "Drobnak", "Jure", "" ] ]
In these proceedings we explore the possibility of new physics manifesting itself in rare top quark decays. In particular, we adopt an effective theory description of FCNC t -> q V top quark decays and possible deviations from the SM form of tWb vertices which would affect the helicity fractions of the W boson produced in the main decay channel of top quark.
2012.01363
Malgorzata Worek
Giuseppe Bevilacqua, Huan-Yu Bi, Heribertus Bayu Hartanto, Manfred Kraus, Jasmina Nasufi and Malgorzata Worek
NLO QCD corrections to off-shell ${t\bar{t}W^\pm}$ production at the LHC: Correlations and Asymmetries
24 pages, 11 figures, 7 tables. Asymmetry plots and citations added, discussion of effects beyond NLO in QCD added. The discussion on PDF uncertainties has been extended. The version to appear in the European Physical Journal C
Eur. Phys. J. C 81 (2021) 675
10.1140/epjc/s10052-021-09478-x
TTK-20-43, P3H-20-078, CAVENDISH-HEP-20/14
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recent discrepancies between theoretical predictions and experimental data in multi-lepton plus $b$-jets analyses for the $t\bar{t}W^\pm$ process, as reported by the ATLAS collaboration, have indicated that more accurate theoretical predictions and high precision observables are needed to constrain numerous new physics scenarios in this channel. To this end we employ NLO QCD computations with full off-shell top quark effects included to provide theoretical predictions for the ${\cal R}= \sigma_{t\bar{t}W^+}/\sigma_{t\bar{t}W^-}$ cross section ratio at the LHC with $\sqrt{s}=13$ TeV. Depending on the transverse momentum cut on the $b$-jet we obtain $2\% -3 \%$ theoretical precision on ${\cal R}$, which should help to shed some light on new physics effects that can reveal themselves only once sufficiently precise Standard Model theoretical predictions are available. Furthermore, triggered by these discrepancies we reexamine the charge asymmetry of the top quark and its decay products in the $t\bar{t}W^\pm$ production process. In the case of charge asymmetries, that are uniquely sensitive to the chiral nature of possible new physics in this channel, theoretical uncertainties below $15\%$ are obtained. Additionally, the impact of the top quark decay modelling is scrutinised by explicit comparison with predictions in the narrow-width approximation.
[ { "created": "Wed, 2 Dec 2020 18:03:41 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2021 16:35:46 GMT", "version": "v2" }, { "created": "Sat, 24 Jul 2021 12:40:31 GMT", "version": "v3" } ]
2021-08-04
[ [ "Bevilacqua", "Giuseppe", "" ], [ "Bi", "Huan-Yu", "" ], [ "Hartanto", "Heribertus Bayu", "" ], [ "Kraus", "Manfred", "" ], [ "Nasufi", "Jasmina", "" ], [ "Worek", "Malgorzata", "" ] ]
Recent discrepancies between theoretical predictions and experimental data in multi-lepton plus $b$-jets analyses for the $t\bar{t}W^\pm$ process, as reported by the ATLAS collaboration, have indicated that more accurate theoretical predictions and high precision observables are needed to constrain numerous new physics scenarios in this channel. To this end we employ NLO QCD computations with full off-shell top quark effects included to provide theoretical predictions for the ${\cal R}= \sigma_{t\bar{t}W^+}/\sigma_{t\bar{t}W^-}$ cross section ratio at the LHC with $\sqrt{s}=13$ TeV. Depending on the transverse momentum cut on the $b$-jet we obtain $2\% -3 \%$ theoretical precision on ${\cal R}$, which should help to shed some light on new physics effects that can reveal themselves only once sufficiently precise Standard Model theoretical predictions are available. Furthermore, triggered by these discrepancies we reexamine the charge asymmetry of the top quark and its decay products in the $t\bar{t}W^\pm$ production process. In the case of charge asymmetries, that are uniquely sensitive to the chiral nature of possible new physics in this channel, theoretical uncertainties below $15\%$ are obtained. Additionally, the impact of the top quark decay modelling is scrutinised by explicit comparison with predictions in the narrow-width approximation.
1503.06938
Sumeet Dagaonkar
Sumeet Dagaonkar, Pankaj Jain, John P. Ralston
The Dirac Form Factor Predicts the Pauli Form Factor in the Endpoint Model
12 pages, 3 figures
null
10.1140/epjc/s10052-016-4224-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the momentum-transfer dependence of the proton Pauli form factor $F_{2}$ in the endpoint overlap model. We find the model correctly reproduces the scaling of the ratio of $F_{2}$ with the Dirac Form factor $F_{1}$ observed at the Jefferson Laboratory. The calculation uses the leading-power, leading twist Dirac structure of the quark light-cone wave function, and the same endpoint dependence previously determined from the Dirac form factor $F_{1}$. There are no parameters and no adjustable functions in the endpoint model's prediction for $F_{2}$. The model's predicted ratio $F_{2}(Q^{2})/F_{1}(Q^{2})$ is quite insensitive to the endpoint wave function, which explains why the observed ratio scales like $1/Q$ down to rather low momentum transfers. The endpoint model appears to be the only comprehensive model consistent with all form factor information as well as reproducing fixed-angle proton-proton scattering at large momentum transfer. Any one of the processes is capable of predicting the others.
[ { "created": "Tue, 24 Mar 2015 07:39:08 GMT", "version": "v1" } ]
2016-07-20
[ [ "Dagaonkar", "Sumeet", "" ], [ "Jain", "Pankaj", "" ], [ "Ralston", "John P.", "" ] ]
We compute the momentum-transfer dependence of the proton Pauli form factor $F_{2}$ in the endpoint overlap model. We find the model correctly reproduces the scaling of the ratio of $F_{2}$ with the Dirac Form factor $F_{1}$ observed at the Jefferson Laboratory. The calculation uses the leading-power, leading twist Dirac structure of the quark light-cone wave function, and the same endpoint dependence previously determined from the Dirac form factor $F_{1}$. There are no parameters and no adjustable functions in the endpoint model's prediction for $F_{2}$. The model's predicted ratio $F_{2}(Q^{2})/F_{1}(Q^{2})$ is quite insensitive to the endpoint wave function, which explains why the observed ratio scales like $1/Q$ down to rather low momentum transfers. The endpoint model appears to be the only comprehensive model consistent with all form factor information as well as reproducing fixed-angle proton-proton scattering at large momentum transfer. Any one of the processes is capable of predicting the others.
hep-ph/9710543
Edmond Iancu
Edmond Iancu (Service de Physique Theorique, Saclay, France)
Effective theory for real-time dynamics in hot gauge theories
11 pages, LaTeX, major rewriting, new title, new references
null
10.1016/S0370-2693(98)00772-2
Saclay-T97/123
hep-ph
null
For a high temperature non-Abelian plasma, we reformulate the hard thermal loop approximation as an effective classical thermal field theory for the soft modes. The effective theory is written in local Hamiltonian form, and the thermal partition function is explicitly constructed. It involves an ultraviolet cutoff which separates between hard and soft degrees of freedom in a gauge-invariant way, together with counterterms which cancel the cutoff dependence in the soft correlation functions. The effective theory is well suited for numerical studies of the non-perturbative dynamics in real time, in particular, for the computation of the baryon number violation rate at high temperature.
[ { "created": "Thu, 30 Oct 1997 17:32:44 GMT", "version": "v1" }, { "created": "Tue, 31 Mar 1998 13:04:42 GMT", "version": "v2" } ]
2009-10-30
[ [ "Iancu", "Edmond", "", "Service de Physique Theorique, Saclay, France" ] ]
For a high temperature non-Abelian plasma, we reformulate the hard thermal loop approximation as an effective classical thermal field theory for the soft modes. The effective theory is written in local Hamiltonian form, and the thermal partition function is explicitly constructed. It involves an ultraviolet cutoff which separates between hard and soft degrees of freedom in a gauge-invariant way, together with counterterms which cancel the cutoff dependence in the soft correlation functions. The effective theory is well suited for numerical studies of the non-perturbative dynamics in real time, in particular, for the computation of the baryon number violation rate at high temperature.
1905.07963
Conny Beskidt
C. Beskidt (1), W. de Boer (1), ((1) Karlsruhe Institute of Technology, Germany)
An effective scanning method of the NMSSM parameter space
15 pages, 5 figures
Phys. Rev. D 100, 055007 (2019)
10.1103/PhysRevD.100.055007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The next-to-minimal supersymmetric standard model (NMSSM) naturally provides a 125 GeV Higgs boson without the need for large loop corrections from multi-TeV stop quarks. Furthermore, the NMSSM provides an electroweak scale dark matter candidate consistent with all experimental data, like relic density and non-observation of direct dark matter signals with the present experimental sensitivity. However, more free parameters are introduced in the NMSSM, which are strongly correlated. A simple parameter scan without knowing the correlation matrix is not efficient and can miss significant regions of the parameter space. We introduce a new technique to sample the NMSSM parameter space, which takes into account the correlations. For this we project the 7D NMSSM parameter space onto the 3D Higgs boson mass parameter space. The reduced dimensionality allows for a non-random sampling and therefore a complete coverage of the allowed NMSSM parameters. In addition, the parameter correlations and possible deviations of the signal strengths of the observed 125 Higgs boson from the SM values are easily predicted.
[ { "created": "Mon, 20 May 2019 09:49:04 GMT", "version": "v1" } ]
2019-09-18
[ [ "Beskidt", "C.", "" ], [ "de Boer", "W.", "" ] ]
The next-to-minimal supersymmetric standard model (NMSSM) naturally provides a 125 GeV Higgs boson without the need for large loop corrections from multi-TeV stop quarks. Furthermore, the NMSSM provides an electroweak scale dark matter candidate consistent with all experimental data, like relic density and non-observation of direct dark matter signals with the present experimental sensitivity. However, more free parameters are introduced in the NMSSM, which are strongly correlated. A simple parameter scan without knowing the correlation matrix is not efficient and can miss significant regions of the parameter space. We introduce a new technique to sample the NMSSM parameter space, which takes into account the correlations. For this we project the 7D NMSSM parameter space onto the 3D Higgs boson mass parameter space. The reduced dimensionality allows for a non-random sampling and therefore a complete coverage of the allowed NMSSM parameters. In addition, the parameter correlations and possible deviations of the signal strengths of the observed 125 Higgs boson from the SM values are easily predicted.
hep-ph/0303198
Ulf-G. Mei{\ss}ner
V\'eronique Bernard, Thomas R. Hemmert, Ulf-G. Mei{\ss}ner
Infrared regularization with spin-3/2 fields
9 pp, 1 fig
Phys.Lett. B565 (2003) 137-145
10.1016/S0370-2693(03)00538-0
null
hep-ph hep-th nucl-th
null
We present a Lorentz-invariant formulation of baryon chiral perturbation theory including spin-3/2 fields. Particular attention is paid to the projection on the spin-3/2 components of the delta fields. We also discuss the nucleon mass and the pion-nucleon sigma term.
[ { "created": "Mon, 24 Mar 2003 13:03:12 GMT", "version": "v1" } ]
2009-11-10
[ [ "Bernard", "Véronique", "" ], [ "Hemmert", "Thomas R.", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We present a Lorentz-invariant formulation of baryon chiral perturbation theory including spin-3/2 fields. Particular attention is paid to the projection on the spin-3/2 components of the delta fields. We also discuss the nucleon mass and the pion-nucleon sigma term.
1211.6294
C\'edric Lorc\'e
Cedric Lorce (IPNO and LPT, Orsay) and Barbara Pasquini (Pavia U. and INFN, Pavia)
Accessing the quark orbital angular momentum with Wigner distributions
4 pages, 1 figure, contribution to the proceedings of the DIFFRACTION 2012 Workshop, Sep 10-15, Puerto del Carmen, Spain
null
10.1063/1.4802141
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The quark orbital angular momentum (OAM) has been recognized as an important piece of the proton spin puzzle. A lot of effort has been invested in trying to extract it quantitatively from the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs), which are accessed in high-energy processes and provide three-dimensional pictures of the nucleon. Recently, we have shown that it is more natural to access the quark OAM from the phase-space or Wigner distributions. We discuss the concept of Wigner distributions in the context of quantum field theory and show how they are related to the GPDs and the TMDs. We summarize the different definitions discussed in the literature for the quark OAM and show how they can in principle be extracted from the Wigner distributions.
[ { "created": "Tue, 27 Nov 2012 13:13:03 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2012 09:07:48 GMT", "version": "v2" } ]
2015-06-12
[ [ "Lorce", "Cedric", "", "IPNO and LPT, Orsay" ], [ "Pasquini", "Barbara", "", "Pavia U. and\n INFN, Pavia" ] ]
The quark orbital angular momentum (OAM) has been recognized as an important piece of the proton spin puzzle. A lot of effort has been invested in trying to extract it quantitatively from the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs), which are accessed in high-energy processes and provide three-dimensional pictures of the nucleon. Recently, we have shown that it is more natural to access the quark OAM from the phase-space or Wigner distributions. We discuss the concept of Wigner distributions in the context of quantum field theory and show how they are related to the GPDs and the TMDs. We summarize the different definitions discussed in the literature for the quark OAM and show how they can in principle be extracted from the Wigner distributions.
hep-ph/9410265
null
Yung Su Tsai
Production of Polarized tau Pairs and Tests of CP Violation Using Polarized e+e- Colliders Near Threshold
30 pages, 5 figures, uuencoded file, SLAC-PUB-6685
Phys.Rev.D51:3172-3181,1995
10.1103/PhysRevD.51.3172
null
hep-ph
null
We consider the production of tau pairs by electron-positron colliding beams at the maximum cross section near the threshold. At this energy tau pairs are produced mostly in the s-wave which implies that the spin of the tau pairs are almost always pointing in the beam direction independent of the production angle. When both electrons and positrons are longitudinally polarized in the same direction, for example 90%, one can obtain tau pairs with 99% polarization in the direction of the polarization vectors of the incident beams. Tests of CP violation and study of the structure of weak interactions using such polarized tau pairs are discussed.
[ { "created": "Tue, 11 Oct 1994 20:08:44 GMT", "version": "v1" } ]
2009-12-30
[ [ "Tsai", "Yung Su", "" ] ]
We consider the production of tau pairs by electron-positron colliding beams at the maximum cross section near the threshold. At this energy tau pairs are produced mostly in the s-wave which implies that the spin of the tau pairs are almost always pointing in the beam direction independent of the production angle. When both electrons and positrons are longitudinally polarized in the same direction, for example 90%, one can obtain tau pairs with 99% polarization in the direction of the polarization vectors of the incident beams. Tests of CP violation and study of the structure of weak interactions using such polarized tau pairs are discussed.
hep-ph/0110244
Esteban Calzetta
Mariana Gra\~na and Esteban Calzetta
Reheating and turbulence
10 pages, one figure included in text
Phys.Rev. D65 (2002) 063522
10.1103/PhysRevD.65.063522
null
hep-ph astro-ph
null
We show that the ''turbulent'' particle spectra found in numerical simulations of the behavior of matter fields during reheating admit a simple interpretation in terms of hydrodynamic models of the reheating period. We predict a particle number spectrum $n_{k}\propto k^{-\alpha}$ with $\alpha \sim 2$ for $k\to 0.$
[ { "created": "Wed, 17 Oct 2001 21:12:12 GMT", "version": "v1" }, { "created": "Thu, 17 Jan 2002 17:18:09 GMT", "version": "v2" } ]
2016-08-16
[ [ "Graña", "Mariana", "" ], [ "Calzetta", "Esteban", "" ] ]
We show that the ''turbulent'' particle spectra found in numerical simulations of the behavior of matter fields during reheating admit a simple interpretation in terms of hydrodynamic models of the reheating period. We predict a particle number spectrum $n_{k}\propto k^{-\alpha}$ with $\alpha \sim 2$ for $k\to 0.$
2203.08347
Christopher Potter
Laura Jeanty, Laura Nosler, Chris Potter
Sensitivity to decays of long-lived dark photons at the ILC (A Snowmass White Paper)
Expanded discussion of backgrounds, additional figures and tables
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the sensitivity to long-lived dark photons produced in Higgstrahlung events via the Higgs portal, $H \rightarrow \gamma_{D} \gamma_{D}$, with the Silicon Detector (SiD) at the International Linear Collider (ILC). These events provide a useful benchmark for tracking and vertex detector performance with long-lived particle decays at displaced vertices. The ILC is one of several Higgs factories proposed by the international community to study the properties of the Higgs boson at high precision.
[ { "created": "Wed, 16 Mar 2022 01:55:15 GMT", "version": "v1" }, { "created": "Sat, 25 Jun 2022 13:53:57 GMT", "version": "v2" } ]
2022-06-28
[ [ "Jeanty", "Laura", "" ], [ "Nosler", "Laura", "" ], [ "Potter", "Chris", "" ] ]
We investigate the sensitivity to long-lived dark photons produced in Higgstrahlung events via the Higgs portal, $H \rightarrow \gamma_{D} \gamma_{D}$, with the Silicon Detector (SiD) at the International Linear Collider (ILC). These events provide a useful benchmark for tracking and vertex detector performance with long-lived particle decays at displaced vertices. The ILC is one of several Higgs factories proposed by the international community to study the properties of the Higgs boson at high precision.
1305.4329
Hong Mao
Hong Mao
On the symmetry improved CJT formalism in the $O(4)$ linear sigma model
11 pages, 3 figures, corrected typos and added references, Accepted for publication in Nuclear Physics A
Nuclear Physics A 925 (2014) 185-198
10.1016/j.nuclphysa.2014.02.011
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By using the symmetry improved CJT effective formalism developed by Pilaftsis and Teresi, the chiral phase transition is reconsidered in the framework of the $O(4)$ linear sigma model in chiral limit. Our results confirm the restorations of the second-order phase transition and the Goldstone theorem in the Hartree approximation. Finally, we explicitly calculate the effective potentials via the order parameter for various temperatures and address advantages of the present method in comparison with the $O(N)$ model in large-$N$ approximation.
[ { "created": "Sun, 19 May 2013 06:35:06 GMT", "version": "v1" }, { "created": "Thu, 23 May 2013 05:56:31 GMT", "version": "v2" }, { "created": "Wed, 12 Jun 2013 03:55:44 GMT", "version": "v3" }, { "created": "Mon, 17 Feb 2014 23:17:01 GMT", "version": "v4" }, { "c...
2014-03-11
[ [ "Mao", "Hong", "" ] ]
By using the symmetry improved CJT effective formalism developed by Pilaftsis and Teresi, the chiral phase transition is reconsidered in the framework of the $O(4)$ linear sigma model in chiral limit. Our results confirm the restorations of the second-order phase transition and the Goldstone theorem in the Hartree approximation. Finally, we explicitly calculate the effective potentials via the order parameter for various temperatures and address advantages of the present method in comparison with the $O(N)$ model in large-$N$ approximation.
1105.4498
Matthew Wingate
Matthew Wingate
Lattice QCD Calculations with b Quarks: Status and Prospects
8 pages. Invited talk at the 13th International Conference on B-Physics at Hadron Machines (BEAUTY 2011), 4-8 April 2011, Amsterdam, The Netherlands, to appear as PoS(BEAUTY 2011)057. Version 2: updated discussion of UTfit Collaboration's LQCD inputs
null
null
DAMTP-2011-31
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This talk gives an overview of how lattice QCD calculations are influencing quark flavor physics. The first part of the talk focuses on the climb to higher precision; the second part surveys views along less-trodden paths.
[ { "created": "Mon, 23 May 2011 13:34:18 GMT", "version": "v1" }, { "created": "Mon, 30 May 2011 15:08:16 GMT", "version": "v2" } ]
2011-05-31
[ [ "Wingate", "Matthew", "" ] ]
This talk gives an overview of how lattice QCD calculations are influencing quark flavor physics. The first part of the talk focuses on the climb to higher precision; the second part surveys views along less-trodden paths.
hep-ph/0601217
Wolfgang Kilian
W. Kilian and P.M. Zerwas
ILC: Physics Scenarios
28pp, Talk 2005 Snowmass Workshop
ECONFC0508141:PLEN0003,2005
null
DESY 06-012
hep-ph
null
Experiments in the energy range from the scale of electroweak symmetry breaking to the TeV scale are expected to be crucial for unraveling the microscopic structure of matter and forces. The high precision which should be achieved in experiments at lepton colliders, is a necessary ingredient for providing a comprehensive picture of the mechanism breaking the electroweak symmetries and generating mass, the unification of forces, involving most likely supersymmetry, and the structure of space-time at small distances. In addition, clarifying the nature of the particles which build up cold dark matter in the universe, needs a lepton collider to match the high experimental precision which will be reached in cosmology experiments.
[ { "created": "Thu, 26 Jan 2006 16:16:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kilian", "W.", "" ], [ "Zerwas", "P. M.", "" ] ]
Experiments in the energy range from the scale of electroweak symmetry breaking to the TeV scale are expected to be crucial for unraveling the microscopic structure of matter and forces. The high precision which should be achieved in experiments at lepton colliders, is a necessary ingredient for providing a comprehensive picture of the mechanism breaking the electroweak symmetries and generating mass, the unification of forces, involving most likely supersymmetry, and the structure of space-time at small distances. In addition, clarifying the nature of the particles which build up cold dark matter in the universe, needs a lepton collider to match the high experimental precision which will be reached in cosmology experiments.
hep-ph/9708412
Randy Kobes
M. Carrington, R. Kobes, and E. Petitgirard
Cancellation of ladder graphs in an effective expansion
14 pages, 8 figures, LaTeX, uses epsf and revtex, also available at http://theory.uwinnipeg.ca/users/randy/webfiles/ladder.uu
Phys.Rev. D57 (1998) 2631-2634
10.1103/PhysRevD.57.2631
WIN-97-12
hep-ph
null
A resummation of ladder graphs is important in cases where infrared, collinear, or light-cone singularities render the loop expansion invalid, especially at high temperature where these effects are often enhanced. It has been noted in some recent examples of this resummation that the ladder graphs are canceled by other types of terms. In this note we show that this cancellation is quite general, and for the most part algebraic.
[ { "created": "Wed, 20 Aug 1997 03:32:04 GMT", "version": "v1" } ]
2009-10-30
[ [ "Carrington", "M.", "" ], [ "Kobes", "R.", "" ], [ "Petitgirard", "E.", "" ] ]
A resummation of ladder graphs is important in cases where infrared, collinear, or light-cone singularities render the loop expansion invalid, especially at high temperature where these effects are often enhanced. It has been noted in some recent examples of this resummation that the ladder graphs are canceled by other types of terms. In this note we show that this cancellation is quite general, and for the most part algebraic.
1411.4085
Stefan H\"oche
Stefan H\"oche
Introduction to parton-shower event generators
40 pages, 12 figures. Lectures presented at TASI 2014
null
null
SLAC-PUB 16160
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This lecture discusses the physics implemented by Monte Carlo event generators for hadron colliders. It details the construction of parton showers and the matching of parton showers to fixed-order calculations at higher orders in perturbative QCD. It also discusses approaches to merge calculations for a varying number of jets, the interface to the underlying event and hadronization.
[ { "created": "Fri, 14 Nov 2014 23:58:47 GMT", "version": "v1" }, { "created": "Thu, 18 Jun 2015 19:13:29 GMT", "version": "v2" } ]
2015-06-19
[ [ "Höche", "Stefan", "" ] ]
This lecture discusses the physics implemented by Monte Carlo event generators for hadron colliders. It details the construction of parton showers and the matching of parton showers to fixed-order calculations at higher orders in perturbative QCD. It also discusses approaches to merge calculations for a varying number of jets, the interface to the underlying event and hadronization.
hep-ph/9807374
Pierre Sikivie
S. Chang (U. of Florida), C. Hagmann (LLNL) and P. Sikivie (U. of Florida)
Studies of the motion and decay of axion walls bounded by strings
37 pages, 10 figures, a minor mistake was corrected, several references and comments were added
Phys.Rev. D59 (1999) 023505
10.1103/PhysRevD.59.023505
UFIFT-HEP-98-12
hep-ph astro-ph
null
We discuss the appearance at the QCD phase transition, and the subsequent decay, of axion walls bounded by strings in N=1 axion models. We argue on intuitive grounds that the main decay mechanism is into barely relativistic axions. We present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is $<\omega_a > \simeq 7 m_a$ for $v_a/m_a \simeq 500$. $<\omega_a>$ is found to increase approximately linearly with $\ln(v_a/m_a)$. Extrapolation of this behaviour yields $<\omega_a> \sim 60 m_a$ in axion models of interest. We find that the contribution to the cosmological energy density of axions from wall decay is of the same order of magnitude as that from vacuum realignment, with however large uncertainties. The velocity dispersion of axions from wall decay is found to be larger, by a factor $10^3$ or so, than that of axions from vacuum realignment and string decay. We discuss the implications of this for the formation and evolution of axion miniclusters and for the direct detection of axion dark matter on Earth. Finally we discuss the cosmology of axion models with $N>1$ in which the domain wall problem is solved by introducing a small U$_{PQ}$(1) breaking interaction. We find that in this case the walls decay into gravitational waves.
[ { "created": "Tue, 14 Jul 1998 20:17:04 GMT", "version": "v1" }, { "created": "Tue, 22 Sep 1998 15:13:29 GMT", "version": "v2" } ]
2009-10-31
[ [ "Chang", "S.", "", "U. of Florida" ], [ "Hagmann", "C.", "", "LLNL" ], [ "Sikivie", "P.", "", "U. of\n Florida" ] ]
We discuss the appearance at the QCD phase transition, and the subsequent decay, of axion walls bounded by strings in N=1 axion models. We argue on intuitive grounds that the main decay mechanism is into barely relativistic axions. We present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is $<\omega_a > \simeq 7 m_a$ for $v_a/m_a \simeq 500$. $<\omega_a>$ is found to increase approximately linearly with $\ln(v_a/m_a)$. Extrapolation of this behaviour yields $<\omega_a> \sim 60 m_a$ in axion models of interest. We find that the contribution to the cosmological energy density of axions from wall decay is of the same order of magnitude as that from vacuum realignment, with however large uncertainties. The velocity dispersion of axions from wall decay is found to be larger, by a factor $10^3$ or so, than that of axions from vacuum realignment and string decay. We discuss the implications of this for the formation and evolution of axion miniclusters and for the direct detection of axion dark matter on Earth. Finally we discuss the cosmology of axion models with $N>1$ in which the domain wall problem is solved by introducing a small U$_{PQ}$(1) breaking interaction. We find that in this case the walls decay into gravitational waves.
1705.03897
Yanou Cui
Yanou Cui and Francesco D'Eramo
Surprises from Complete Vector Portal Theories: New Insights into the Dark Sector and its Interplay with Higgs Physics
5 pages, 3 figures; v2: minor corrections, references added, journal version
Phys. Rev. D 96, 095006 (2017)
10.1103/PhysRevD.96.095006
SCIPP 17/05
hep-ph astro-ph.CO hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study UV complete theories where the Standard Model (SM) gauge group is extended with a new abelian $U(1)$, and the field content is augmented by an arbitrary number of scalar and fermion SM singlets, potentially including dark matter (DM) candidates. Considerations such as classical and quantum gauge invariance of the full theory and S-matrix unitarity, not applicable within a simplified model approach, are shown to have significant phenomenological consequences. The lack of gauge anomalies leads to compact relations among the $U(1)$ fermion charges, and puts a lower bound on the number of dark fermions. Contrary to naive expectations, the DM annihilation to Zh is found to be p-wave suppressed, as hinted by perturbative unitarity of S-matrix, with dramatic implications for DM thermal relic density and indirect searches. Within this framework, the interplay between dark matter, new vector boson and Higgs physics is rather natural and generic.
[ { "created": "Wed, 10 May 2017 18:00:14 GMT", "version": "v1" }, { "created": "Tue, 21 Nov 2017 23:58:53 GMT", "version": "v2" } ]
2017-11-29
[ [ "Cui", "Yanou", "" ], [ "D'Eramo", "Francesco", "" ] ]
We study UV complete theories where the Standard Model (SM) gauge group is extended with a new abelian $U(1)$, and the field content is augmented by an arbitrary number of scalar and fermion SM singlets, potentially including dark matter (DM) candidates. Considerations such as classical and quantum gauge invariance of the full theory and S-matrix unitarity, not applicable within a simplified model approach, are shown to have significant phenomenological consequences. The lack of gauge anomalies leads to compact relations among the $U(1)$ fermion charges, and puts a lower bound on the number of dark fermions. Contrary to naive expectations, the DM annihilation to Zh is found to be p-wave suppressed, as hinted by perturbative unitarity of S-matrix, with dramatic implications for DM thermal relic density and indirect searches. Within this framework, the interplay between dark matter, new vector boson and Higgs physics is rather natural and generic.
hep-ph/9610517
Ben Allanach
B.C. Allanach (Rutherford), S.F. King (Southampton U.), G.K. Leontaris (Ioannina U.), S.Lola (CERN)
Yukawa Textures in String Unified Models With SU(4)xO(4) Symmetry
Revised version to include string section on origin of non-renormalisable operators. 54 pages LaTeX
Phys.Rev.D56:2632-2655,1997
10.1103/PhysRevD.56.2632
CERN-TH-96-300. IOA-05-96. RAL-TR-96-091. SHEP-96-29
hep-ph
null
We discuss the origin of Yukawa textures in the string-inspired and string derived models based on the gauge group SU(4)xSU(2)_LxSU(2)_R supplemented by a U(1)_X gauged family symmetry. The gauge symmetries are broken down to those of the minimal supersymmetric standard model which is the effective theory below 10^16 GeV. The combination of the U(1)_X family symmetry and the Pati-Salam gauge group leads to a successful and predictive set of Yukawa textures involving two kinds of texture zeroes: horizontal and vertical texture zeroes. We discuss both symmetric and non-symmetric textures in models of this kind, and in the second case perform a detailed numerical fit to the charged fermion mass and mixing data. Two of the Yukawa textures allow a low energy fit to the data with a total chi^2 of 0.39 and 1.02 respectively, for three degrees of freedom. We also make a first attempt at deriving the non - renormalisable operators required for the Yukawa textures from string theory.
[ { "created": "Mon, 28 Oct 1996 17:14:11 GMT", "version": "v1" }, { "created": "Fri, 14 Mar 1997 11:10:50 GMT", "version": "v2" }, { "created": "Tue, 18 Mar 1997 14:30:57 GMT", "version": "v3" } ]
2014-11-17
[ [ "Allanach", "B. C.", "", "Rutherford" ], [ "King", "S. F.", "", "Southampton U." ], [ "Leontaris", "G. K.", "", "Ioannina U." ], [ "Lola", "S.", "", "CERN" ] ]
We discuss the origin of Yukawa textures in the string-inspired and string derived models based on the gauge group SU(4)xSU(2)_LxSU(2)_R supplemented by a U(1)_X gauged family symmetry. The gauge symmetries are broken down to those of the minimal supersymmetric standard model which is the effective theory below 10^16 GeV. The combination of the U(1)_X family symmetry and the Pati-Salam gauge group leads to a successful and predictive set of Yukawa textures involving two kinds of texture zeroes: horizontal and vertical texture zeroes. We discuss both symmetric and non-symmetric textures in models of this kind, and in the second case perform a detailed numerical fit to the charged fermion mass and mixing data. Two of the Yukawa textures allow a low energy fit to the data with a total chi^2 of 0.39 and 1.02 respectively, for three degrees of freedom. We also make a first attempt at deriving the non - renormalisable operators required for the Yukawa textures from string theory.
hep-ph/9808404
Bruce Bassett
Bruce A. Bassett (Oxford), David I. Kaiser (Harvard) and Roy Maartens (Portsmouth)
General Relativistic effects in preheating
10 pages. 1 .ps fig. Matches version to appear in Phys Lett B
Phys.Lett. B455 (1999) 84-89
10.1016/S0370-2693(99)00478-5
HUTP-98/A058, PU-RCG-98/11
hep-ph astro-ph gr-qc hep-th
null
General relativistic effects in the form of metric perturbations are usually neglected in the preheating era that follows inflation. We argue that in realistic multi-field models these effects are in fact crucial, and the fully coupled system of metric and quantum field fluctuations needs to be considered. Metric perturbations are resonantly amplified, breaking the scale-invariance of the primordial spectrum, and in turn stimulate scalar field resonances via gravitational rescattering. This non-gravitationally dominated nonlinear growth of gravitational fluctuations may have significant effects on the Doppler peaks in the cosmic background radiation, primordial black hole formation, gravitational waves and nonthermal symmetry restoration.
[ { "created": "Tue, 25 Aug 1998 08:31:15 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 1998 15:50:41 GMT", "version": "v2" }, { "created": "Mon, 19 Apr 1999 15:31:44 GMT", "version": "v3" } ]
2009-10-31
[ [ "Bassett", "Bruce A.", "", "Oxford" ], [ "Kaiser", "David I.", "", "Harvard" ], [ "Maartens", "Roy", "", "Portsmouth" ] ]
General relativistic effects in the form of metric perturbations are usually neglected in the preheating era that follows inflation. We argue that in realistic multi-field models these effects are in fact crucial, and the fully coupled system of metric and quantum field fluctuations needs to be considered. Metric perturbations are resonantly amplified, breaking the scale-invariance of the primordial spectrum, and in turn stimulate scalar field resonances via gravitational rescattering. This non-gravitationally dominated nonlinear growth of gravitational fluctuations may have significant effects on the Doppler peaks in the cosmic background radiation, primordial black hole formation, gravitational waves and nonthermal symmetry restoration.
1107.4309
Luis Anchordoqui
Luis A. Anchordoqui, Ignatios Antoniadis, Haim Goldberg, Xing Huang, Dieter Lust, Tomasz R. Taylor
Z'-gauge Bosons as Harbingers of Low Mass Strings
To be published in PRD
null
10.1103/PhysRevD.85.086003
MPP-2011-86; LMU-ASC 32/11; CERN-PH-TH/2011-180
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Massive Z'-gauge bosons act as excellent harbingers for string compactifications with a low string scale. In D-brane models they are associated to U(1) gauge symmetries that are either anomalous in four dimensions or exhibit a hidden higher dimensional anomaly. We discuss the possible signals of massive Z'-gauge bosons at hadron collider machines (Tevatron, LHC) in a minimal D-brane model consisting out of four stacks of D-branes. In this construction, there are two massive gauge bosons, which can be naturally associated with baryon number B and B-L (L being lepton number). Here baryon number is always anomalous in four dimensions, whereas the presence of a four-dimensional B-L anomaly depends on the U(1)-charges of the right handed neutrinos. In case B-L is anomaly free, a mass hierarchy between the two associated Z'-gauge bosons can be explained. In our phenomenological discussion about the possible discovery of massive Z'-gauge bosons, we take as a benchmark scenario the dijet plus W signal, recently observed by the CDF Collaboration at Tevatron. It reveals an excess in the dijet mass range 150 GeV/c^2, 4.1\sigma beyond SM expectations. We show that in the context of low-mass string theory this excess can be associated with the production and decay of a leptophobic Z', a singlet partner of SU(3) gluons coupled primarily to baryon number. Even if the CDF signal disappears, as indicated by the more recent D0 results, our analysis can still serve as the basis for future experimental search for massive Z'-gauge bosons in low string scale models. We provide the relevant cross sections for the production of Z'-gauge bosons in the TeV region, leading to predictions that are within reach of the present or the next LHC run.
[ { "created": "Thu, 21 Jul 2011 16:50:06 GMT", "version": "v1" }, { "created": "Thu, 18 Aug 2011 13:35:58 GMT", "version": "v2" }, { "created": "Sat, 24 Mar 2012 12:38:12 GMT", "version": "v3" } ]
2013-05-30
[ [ "Anchordoqui", "Luis A.", "" ], [ "Antoniadis", "Ignatios", "" ], [ "Goldberg", "Haim", "" ], [ "Huang", "Xing", "" ], [ "Lust", "Dieter", "" ], [ "Taylor", "Tomasz R.", "" ] ]
Massive Z'-gauge bosons act as excellent harbingers for string compactifications with a low string scale. In D-brane models they are associated to U(1) gauge symmetries that are either anomalous in four dimensions or exhibit a hidden higher dimensional anomaly. We discuss the possible signals of massive Z'-gauge bosons at hadron collider machines (Tevatron, LHC) in a minimal D-brane model consisting out of four stacks of D-branes. In this construction, there are two massive gauge bosons, which can be naturally associated with baryon number B and B-L (L being lepton number). Here baryon number is always anomalous in four dimensions, whereas the presence of a four-dimensional B-L anomaly depends on the U(1)-charges of the right handed neutrinos. In case B-L is anomaly free, a mass hierarchy between the two associated Z'-gauge bosons can be explained. In our phenomenological discussion about the possible discovery of massive Z'-gauge bosons, we take as a benchmark scenario the dijet plus W signal, recently observed by the CDF Collaboration at Tevatron. It reveals an excess in the dijet mass range 150 GeV/c^2, 4.1\sigma beyond SM expectations. We show that in the context of low-mass string theory this excess can be associated with the production and decay of a leptophobic Z', a singlet partner of SU(3) gluons coupled primarily to baryon number. Even if the CDF signal disappears, as indicated by the more recent D0 results, our analysis can still serve as the basis for future experimental search for massive Z'-gauge bosons in low string scale models. We provide the relevant cross sections for the production of Z'-gauge bosons in the TeV region, leading to predictions that are within reach of the present or the next LHC run.
1308.4455
Ho-Meoyng Choi
Ho-Meoyng Choi (Kyungpook National Univ.) and Chueng-Ryong Ji (North Carolina State Univ.)
Self-consistent covariant description of vector meson decay constants and chirality-even quark-antiquark distribution amplitudes up to twist-3 in the light-front quark model
16 pages, 4 figures
Physical Review D 89, 033011(2014)
10.1103/PhysRevD.89.033011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although the meson decay amplitude described by a two-point function may be regarded as one of the simplest possible physical observable, it is interesting that this apparently simple amplitude bears abundant fundamental informations on QCD vacuum dynamics and chiral symmetry. The light-front zero-mode issue of the vector meson decay constant $f_V$ is in this respect highly non-trivial and deserves careful analyses. We discuss the zero-mode issue in the light-front quark model (LFQM) prediction of $f_V$ from the perspective of the vacuum fluctuation consistent with the chiral symmetry of QCD. We extend the exactly solvable manifestly covariant Bethe-Salpeter model calculation to the more phenomenologically accessible realistic LFQM and present a self-consistent covariant description of $f_V$ analyzing the twist-2 and twist-3 quark-antiquark distribution amplitudes with even chirality.
[ { "created": "Wed, 21 Aug 2013 00:59:56 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 2013 09:01:12 GMT", "version": "v2" }, { "created": "Thu, 20 Feb 2014 02:05:55 GMT", "version": "v3" } ]
2015-06-16
[ [ "Choi", "Ho-Meoyng", "", "Kyungpook National Univ." ], [ "Ji", "Chueng-Ryong", "", "North\n Carolina State Univ." ] ]
Although the meson decay amplitude described by a two-point function may be regarded as one of the simplest possible physical observable, it is interesting that this apparently simple amplitude bears abundant fundamental informations on QCD vacuum dynamics and chiral symmetry. The light-front zero-mode issue of the vector meson decay constant $f_V$ is in this respect highly non-trivial and deserves careful analyses. We discuss the zero-mode issue in the light-front quark model (LFQM) prediction of $f_V$ from the perspective of the vacuum fluctuation consistent with the chiral symmetry of QCD. We extend the exactly solvable manifestly covariant Bethe-Salpeter model calculation to the more phenomenologically accessible realistic LFQM and present a self-consistent covariant description of $f_V$ analyzing the twist-2 and twist-3 quark-antiquark distribution amplitudes with even chirality.
hep-ph/0202186
Baldicchi Massimiliano
G. M. Prosperi
Confinement and bound states in QCD
11 pages, 2 figures, Conference: Color Confinement and Hadrons (Confinement 2000) Osaka, Japan
null
null
null
hep-ph
null
I revue the so called Wilson loop approach to bound state problem in QCD. I shall show how using appropriate path integral representations for the quark propagator in an external field it is possible to obtain corresponding path integral representations for various types of gauge invariant Green functions which have the important feature of involving the gauge field only trough Wilson loop correlators or their generalizations. Two different kinds of representations are used, one given in the form of a semi-relativistic expansion, the second completely relativistic of the Feynmann-Schwinger type. In this way starting from reasonable ansatz on the non perturbative part of the Wilson correlator one can obtain: expressions for the semi relativistic (spin dependent and momentum dependent) q \bar q and 3q potentials, a ``second order'' q \bar q Bethe-Salpeter equation and and a related Dyson-Schwinger equation. I shall concentrate on the three quark potential for which new controversial results have been obtained by lattice numerical simulations and on a three dimensional reduction of the BS equation obtained in the form of the eigenvalue equation of of a squared or a usual mass operator. We shall report on a numerical resolution of such equations which seems to give a comprehensive reproduction of the entire meson spectrum with the exception of light pseudo-scalar bound states for which a complete four dimensional treatment should be necessary.
[ { "created": "Tue, 19 Feb 2002 17:06:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Prosperi", "G. M.", "" ] ]
I revue the so called Wilson loop approach to bound state problem in QCD. I shall show how using appropriate path integral representations for the quark propagator in an external field it is possible to obtain corresponding path integral representations for various types of gauge invariant Green functions which have the important feature of involving the gauge field only trough Wilson loop correlators or their generalizations. Two different kinds of representations are used, one given in the form of a semi-relativistic expansion, the second completely relativistic of the Feynmann-Schwinger type. In this way starting from reasonable ansatz on the non perturbative part of the Wilson correlator one can obtain: expressions for the semi relativistic (spin dependent and momentum dependent) q \bar q and 3q potentials, a ``second order'' q \bar q Bethe-Salpeter equation and and a related Dyson-Schwinger equation. I shall concentrate on the three quark potential for which new controversial results have been obtained by lattice numerical simulations and on a three dimensional reduction of the BS equation obtained in the form of the eigenvalue equation of of a squared or a usual mass operator. We shall report on a numerical resolution of such equations which seems to give a comprehensive reproduction of the entire meson spectrum with the exception of light pseudo-scalar bound states for which a complete four dimensional treatment should be necessary.
0912.0113
Damiano Anselmi
Damiano Anselmi and Martina Taiuti
Renormalization Of High-Energy Lorentz Violating QED
17 pages, 1 figure; v2: typos corrected, some more comments, PRD published version
Phys.Rev.D81:085042,2010
10.1103/PhysRevD.81.085042
IFUP-TH 2009/20
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a QED extension that is unitary, CPT invariant and super-renormalizable, but violates Lorentz symmetry at high energies, and contains higher-dimension operators (LVQED). Divergent diagrams are only one- and two-loop. We compute the one-loop renormalizations at high and low energies and analyse the relation between them. It emerges that the power-like divergences of the low-energy theory are multiplied by arbitrary constants, inherited by the high-energy theory, and therefore can be set to zero at no cost, bypassing the hierarchy problem.
[ { "created": "Tue, 1 Dec 2009 10:12:35 GMT", "version": "v1" }, { "created": "Sun, 9 May 2010 15:57:04 GMT", "version": "v2" } ]
2010-05-12
[ [ "Anselmi", "Damiano", "" ], [ "Taiuti", "Martina", "" ] ]
We study a QED extension that is unitary, CPT invariant and super-renormalizable, but violates Lorentz symmetry at high energies, and contains higher-dimension operators (LVQED). Divergent diagrams are only one- and two-loop. We compute the one-loop renormalizations at high and low energies and analyse the relation between them. It emerges that the power-like divergences of the low-energy theory are multiplied by arbitrary constants, inherited by the high-energy theory, and therefore can be set to zero at no cost, bypassing the hierarchy problem.
hep-ph/9710305
Jose F. Nieves
Juan Carlos D'Olivo and Jose F. Nieves
Nucleon effects on the photon dispersion relations in matter
RevTeX
Phys.Rev. D57 (1998) 3116-3130
10.1103/PhysRevD.57.3116
null
hep-ph
null
We calculate the nucleon contribution to the photon self-energy in a plasma, including the effect of the anomalous magnetic moment of the nucleons. General formulas for the transverse and longitudinal components of the self-energy are obtained and we give explicit results in various limits of physical interest. The formulas are relevant for the study of the photon dispersion relations and the dynamical susceptibility in a nuclear medium such as the core of a supernova, and has implications with regard to the recent suggestion that the Cerenkov process $\nu \to \nu\gamma$ can take place in such a system.
[ { "created": "Thu, 9 Oct 1997 21:44:39 GMT", "version": "v1" } ]
2009-10-30
[ [ "D'Olivo", "Juan Carlos", "" ], [ "Nieves", "Jose F.", "" ] ]
We calculate the nucleon contribution to the photon self-energy in a plasma, including the effect of the anomalous magnetic moment of the nucleons. General formulas for the transverse and longitudinal components of the self-energy are obtained and we give explicit results in various limits of physical interest. The formulas are relevant for the study of the photon dispersion relations and the dynamical susceptibility in a nuclear medium such as the core of a supernova, and has implications with regard to the recent suggestion that the Cerenkov process $\nu \to \nu\gamma$ can take place in such a system.
0809.0779
Ulrich Ellwanger
Ulrich Ellwanger
The constrained NMSSM: mSUGRA and GMSB
6 pages, 5 Figures. Plenary talk given at SUSY 08
AIP Conf.Proc.1078:73-78,2009
10.1063/1.3052054
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review different constrained versions of the NMSSM: the fully constrained cNMSSM with universal boundary conditions for gauginos and all soft scalar masses and trilinear couplings, and the NMSSM with soft terms from Gauge Mediated Supersymmetry Breaking. Regarding the fully constrained cNMSSM, after imposing LEP constraints and the correct dark matter relic density, one single parameter is sufficient to describe the entire Higgs and sparticle spectrum of the model, which then contains always a singlino LSP. The NMSSM with soft terms from GMSB is phenomenologically viable if (and only if) the singlet is allowed to couple directly to the messenger sector; then various ranges in parameter space satisfy constraints from colliders and precision observables. Motivations for and phenomenological features of extra U(1)' gauge symmetries are briefly reviewed.
[ { "created": "Thu, 4 Sep 2008 09:31:14 GMT", "version": "v1" } ]
2009-02-02
[ [ "Ellwanger", "Ulrich", "" ] ]
We review different constrained versions of the NMSSM: the fully constrained cNMSSM with universal boundary conditions for gauginos and all soft scalar masses and trilinear couplings, and the NMSSM with soft terms from Gauge Mediated Supersymmetry Breaking. Regarding the fully constrained cNMSSM, after imposing LEP constraints and the correct dark matter relic density, one single parameter is sufficient to describe the entire Higgs and sparticle spectrum of the model, which then contains always a singlino LSP. The NMSSM with soft terms from GMSB is phenomenologically viable if (and only if) the singlet is allowed to couple directly to the messenger sector; then various ranges in parameter space satisfy constraints from colliders and precision observables. Motivations for and phenomenological features of extra U(1)' gauge symmetries are briefly reviewed.
hep-ph/9907548
Maurizio Lusignoli
Pasquale Di Bari, Paolo Lipari and Maurizio Lusignoli (INFN, Sezione di Roma, and Dipartimento di Fisica, Universita' di Roma "La Sapienza", Roma, Italy)
The $\nu_\mu \leftrightarrow \nu_s$ interpretation of the atmospheric neutrino data and cosmological constraints
45 pages, 14 figures, LaTeX2e; added discussion in subsection 6.3; to appear in International Journal of Modern Physics A
Int.J.Mod.Phys. A15 (2000) 2289-2328
10.1142/S0217751X00000951
ROME1-1259/99
hep-ph astro-ph
null
The data on atmospheric neutrinos can be explained assuming the existence of oscillations between muon neutrinos and light sterile neutrinos with mixing close to maximal, and Delta_m^2 approximately equal to 3 E-3 (eV^2). This interpretation of the data is in potential conflict with the successes of big bang nucleosynthesis (BBN), since oscillations can result in a too large contribution of the sterile state to the energy density of the universe at the epoch of nucleosynthesis. The possibility to evade these cosmological constraints has been recently the object of some controversy. In this work we rediscuss this problem and find that the inclusion of a small mixing of the sterile state with tau neutrino can result in the generation of a large lepton asymmetry that strongly suppress the muon-sterile neutrino oscillations eliminating the possible conflict with BBN bounds. In this scheme the mass of the tau neutrino must be larger than few eV's and is compatible with cosmological bounds. Our calculation is performed using a Pauli-Boltzmann method. In this approach it is also possible to develop analytic calculations that allow physical insight in the processes considered and give support to the numerical results.
[ { "created": "Thu, 29 Jul 1999 14:54:48 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 1999 16:54:21 GMT", "version": "v2" } ]
2017-09-06
[ [ "Di Bari", "Pasquale", "", "INFN, Sezione\n di Roma, and Dipartimento di Fisica, Universita' di Roma \"La Sapienza\", Roma,\n Italy" ], [ "Lipari", "Paolo", "", "INFN, Sezione\n di Roma, and Dipartimento di Fisica, Universita' di Roma \"La Sapienza\", Roma,\n Italy" ], ...
The data on atmospheric neutrinos can be explained assuming the existence of oscillations between muon neutrinos and light sterile neutrinos with mixing close to maximal, and Delta_m^2 approximately equal to 3 E-3 (eV^2). This interpretation of the data is in potential conflict with the successes of big bang nucleosynthesis (BBN), since oscillations can result in a too large contribution of the sterile state to the energy density of the universe at the epoch of nucleosynthesis. The possibility to evade these cosmological constraints has been recently the object of some controversy. In this work we rediscuss this problem and find that the inclusion of a small mixing of the sterile state with tau neutrino can result in the generation of a large lepton asymmetry that strongly suppress the muon-sterile neutrino oscillations eliminating the possible conflict with BBN bounds. In this scheme the mass of the tau neutrino must be larger than few eV's and is compatible with cosmological bounds. Our calculation is performed using a Pauli-Boltzmann method. In this approach it is also possible to develop analytic calculations that allow physical insight in the processes considered and give support to the numerical results.
hep-ph/0504159
Pavel Pobylitsa
P.V. Pobylitsa
Baryon wave function: Large-Nc QCD and lessons from models
58 pages
null
null
null
hep-ph
null
The structure of the 1/Nc expansion for the baryon distribution amplitude in QCD is tested using quark models. Earlier conjectures about this structure based on the evolution equation and on the soft-pion theorem are confirmed by the model analysis. The problem of the calculation of the baryon wave function at large Nc is reduced to the analysis of equations of motion for an effective classical dynamical system.
[ { "created": "Mon, 18 Apr 2005 19:45:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pobylitsa", "P. V.", "" ] ]
The structure of the 1/Nc expansion for the baryon distribution amplitude in QCD is tested using quark models. Earlier conjectures about this structure based on the evolution equation and on the soft-pion theorem are confirmed by the model analysis. The problem of the calculation of the baryon wave function at large Nc is reduced to the analysis of equations of motion for an effective classical dynamical system.
hep-ph/9911312
Shinya Kanemura
S. Kanemura (ITP, Univ. Karlsruhe), T. Kasai (Theory Group, KEK), and Y. Okada (Theory Group, KEK)
Upper and lower bounds of the lightest CP-even Higgs boson in the two-Higgs-doublet model
Talk given by S. Kanemura at the 2nd ECFA/DESY LCWS in Obernai, France (16-19. October 1999), 7 pages including 3 figures
null
10.1016/S0370-2693(99)01351-9
KA-TP-18-1999, KEK-TH-660
hep-ph
null
By imposing validity of the perturbation and stability of vacuum up to an energy scale $\Lambda$ ($\leq 10^{19}$ GeV), we evaluate mass bounds of the lightest CP-even Higgs-boson mass ($m_h$) in the two-Higgs-doublet model (2HDM) with a softly-broken discrete symmetry. The most general bounds are obtained as a function of $\Lambda$ vering all the free parameters under the experimental constraint from the $rho$ parameter and the b \to s \gamma$ results. We find that, while the upper bound is almost the same as in the SM, the lower bound is significantly reduced. In the decoupling regime where the model behaves like the SM at low energy, the lower bound is given, for example, by about 100 GeV for $\Lambda = 10^{19}$ GeV and $m_t = 175$ GeV, which is smaller by about 40 GeV than the corresponding lower bound in the SM. In general case, the $m_h$ is no longer bounded from below by these conditions. If we consider the experimental $b \to s \gamma$ constraint, small $m_h$ are excluded in Model II of the 2HDM.
[ { "created": "Thu, 11 Nov 1999 11:57:51 GMT", "version": "v1" } ]
2009-10-31
[ [ "Kanemura", "S.", "", "ITP, Univ. Karlsruhe" ], [ "Kasai", "T.", "", "Theory Group, KEK" ], [ "Okada", "Y.", "", "Theory Group, KEK" ] ]
By imposing validity of the perturbation and stability of vacuum up to an energy scale $\Lambda$ ($\leq 10^{19}$ GeV), we evaluate mass bounds of the lightest CP-even Higgs-boson mass ($m_h$) in the two-Higgs-doublet model (2HDM) with a softly-broken discrete symmetry. The most general bounds are obtained as a function of $\Lambda$ vering all the free parameters under the experimental constraint from the $rho$ parameter and the b \to s \gamma$ results. We find that, while the upper bound is almost the same as in the SM, the lower bound is significantly reduced. In the decoupling regime where the model behaves like the SM at low energy, the lower bound is given, for example, by about 100 GeV for $\Lambda = 10^{19}$ GeV and $m_t = 175$ GeV, which is smaller by about 40 GeV than the corresponding lower bound in the SM. In general case, the $m_h$ is no longer bounded from below by these conditions. If we consider the experimental $b \to s \gamma$ constraint, small $m_h$ are excluded in Model II of the 2HDM.
1508.06014
Sibo Zheng
Qiurong Mou and Sibo Zheng
A Heavy Scalar at the LHC from Vector Boson Fusion
Published version
Advances in High Energy Physics 2018 (2018) 9314613
10.1155/2018/9314613
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
A hypothetical scalar mixed with the standard model Higgs appears in few contexts of new physics. This study addresses the question what mass range is in the reach of $14$ TeV LHC given different magnitudes of mixing angle $\alpha$, where event simulations are based on production from vector boson fusion channel and decays into SM leptons through ${\rm WW}$ or ${\rm ZZ}$. It indicates that heavy scalar mass up to $539$ GeV and $937$ GeV can be excluded by integrated luminosity of $300$ $\rm{fb}^{-1}$ and $3000$ $\rm{fb}^{-1}$ respectively for $\sin^{2}\alpha$ larger than $0.04$.
[ { "created": "Tue, 25 Aug 2015 02:51:12 GMT", "version": "v1" }, { "created": "Sun, 4 Mar 2018 09:11:13 GMT", "version": "v2" }, { "created": "Thu, 26 Jul 2018 08:03:12 GMT", "version": "v3" } ]
2018-08-15
[ [ "Mou", "Qiurong", "" ], [ "Zheng", "Sibo", "" ] ]
A hypothetical scalar mixed with the standard model Higgs appears in few contexts of new physics. This study addresses the question what mass range is in the reach of $14$ TeV LHC given different magnitudes of mixing angle $\alpha$, where event simulations are based on production from vector boson fusion channel and decays into SM leptons through ${\rm WW}$ or ${\rm ZZ}$. It indicates that heavy scalar mass up to $539$ GeV and $937$ GeV can be excluded by integrated luminosity of $300$ $\rm{fb}^{-1}$ and $3000$ $\rm{fb}^{-1}$ respectively for $\sin^{2}\alpha$ larger than $0.04$.
1405.7427
Russell TerBeek III
Jayden L. Newstead, Russell H. TerBeek
The Reach of Threshold-Corrected Dark QCD
7 pages, 8 figures
Phys. Rev. D 90, 074008 (2014)
10.1103/PhysRevD.90.074008
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a recently-proposed model which posits the existence of composite dark matter, wherein dark "quarks" transforming as fundamentals under an $SU(3)_d$ gauge group undergo a confining phase and form dark baryons. The model attempts to explain both the $\mathcal{O}(1)$ relic density ratio, $\Omega_{\mathrm{dark}}/\Omega_{\mathrm{baryon}}\sim 5.4$, as well as the asymmetric production of both dark and baryonic matter via leptogenesis. Though the solution of $\beta$ functions for $SU(3)_c$ and $SU(3)_d$ constitutes the main drive of the model, no threshold corrections were taken into account as the renormalization scale crosses the mass threshold of the heavy new fields in the model. We extend this work by explicitly calculating the threshold-corrected renormalization-group flow for the theory using an effective-field matching technique. We find that the theory has a much wider range of applicability than previously thought, and that a significant fraction of models (defined by the number of fields contained therein) is able to account for the observed relic density.
[ { "created": "Thu, 29 May 2014 00:04:46 GMT", "version": "v1" } ]
2014-10-08
[ [ "Newstead", "Jayden L.", "" ], [ "TerBeek", "Russell H.", "" ] ]
We consider a recently-proposed model which posits the existence of composite dark matter, wherein dark "quarks" transforming as fundamentals under an $SU(3)_d$ gauge group undergo a confining phase and form dark baryons. The model attempts to explain both the $\mathcal{O}(1)$ relic density ratio, $\Omega_{\mathrm{dark}}/\Omega_{\mathrm{baryon}}\sim 5.4$, as well as the asymmetric production of both dark and baryonic matter via leptogenesis. Though the solution of $\beta$ functions for $SU(3)_c$ and $SU(3)_d$ constitutes the main drive of the model, no threshold corrections were taken into account as the renormalization scale crosses the mass threshold of the heavy new fields in the model. We extend this work by explicitly calculating the threshold-corrected renormalization-group flow for the theory using an effective-field matching technique. We find that the theory has a much wider range of applicability than previously thought, and that a significant fraction of models (defined by the number of fields contained therein) is able to account for the observed relic density.
hep-ph/0410263
Erik Barto\v{s}
E. Bartos, S. R. Gevorkyan, E. A. Kuraev, N. N. Nikolaev
Multiple exchanges in lepton pair production in high--energy heavy ion collisions
20 pages, 7 figures, REVTeX4 format
J.Exp.Theor.Phys. 100 (2005) 645-655; Zh.Eksp.Teor.Fiz. 100 (2005) 732-743
10.1134/1.1926426
null
hep-ph
null
The recent analysis of nuclear distortions in DIS off nuclei revealed a breaking of the conventional hard factorization for multijet observable. The related pQCD analysis of distortion effects for jet production in nucleus-nucleus collisions is as yet lacking. As a testing ground for such an analysis we consider the Abelian problem of higher order Coulomb distortions of the spectrum of lepton pairs produced in peripheral nuclear collisions. We report an explicit calculation of the contribution to the lepton pair production in the collision of two photons from one nucleus with two photons from the other nucleus, $2\gamma + 2\gamma \to \m{l}^+\m{l}^-$. The dependence of this amplitude on the transverse momenta has a highly nontrivial form the origin of which can be traced to the mismatch of the conservation of the Sudakov components for the momentum of leptons in the Coulomb field of the oppositely moving nuclei. The result suggests that the familiar eikonalization of Coulomb distortions breaks down for the oppositely moving Coulomb centers, which is bad news from the point of view of extensions to the pQCD treatment of jet production in nuclear collisions. On the other hand, we notice that the amplitude for the $2\gamma + 2\gamma \to \m{l}^+\m{l}^-$ process has a logarithmic enhancement for the lepton pairs with large transverse momentum, which is absent for $n\gamma + m\gamma \to \m{l}^+\m{l}^-$ processes with $m,n > 2$. We discuss the general structure of multiple exchanges and show how to deal with higher order terms which cannot be eikonalized.
[ { "created": "Tue, 19 Oct 2004 14:34:54 GMT", "version": "v1" } ]
2015-06-25
[ [ "Bartos", "E.", "" ], [ "Gevorkyan", "S. R.", "" ], [ "Kuraev", "E. A.", "" ], [ "Nikolaev", "N. N.", "" ] ]
The recent analysis of nuclear distortions in DIS off nuclei revealed a breaking of the conventional hard factorization for multijet observable. The related pQCD analysis of distortion effects for jet production in nucleus-nucleus collisions is as yet lacking. As a testing ground for such an analysis we consider the Abelian problem of higher order Coulomb distortions of the spectrum of lepton pairs produced in peripheral nuclear collisions. We report an explicit calculation of the contribution to the lepton pair production in the collision of two photons from one nucleus with two photons from the other nucleus, $2\gamma + 2\gamma \to \m{l}^+\m{l}^-$. The dependence of this amplitude on the transverse momenta has a highly nontrivial form the origin of which can be traced to the mismatch of the conservation of the Sudakov components for the momentum of leptons in the Coulomb field of the oppositely moving nuclei. The result suggests that the familiar eikonalization of Coulomb distortions breaks down for the oppositely moving Coulomb centers, which is bad news from the point of view of extensions to the pQCD treatment of jet production in nuclear collisions. On the other hand, we notice that the amplitude for the $2\gamma + 2\gamma \to \m{l}^+\m{l}^-$ process has a logarithmic enhancement for the lepton pairs with large transverse momentum, which is absent for $n\gamma + m\gamma \to \m{l}^+\m{l}^-$ processes with $m,n > 2$. We discuss the general structure of multiple exchanges and show how to deal with higher order terms which cannot be eikonalized.
2107.01827
Anatoly Butkevich
A.V. Butkevich
Analysis of flux-integrated semi-exclusive cross sections for charged current quasi-elastic neutrino scattering off 40Ar at energies available at the MicroBooNE experiment
17 pages, 7 figures
null
10.1103/PhysRevC.105.025501
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Flux-integrated semi-exclusive differential and integral cross sections for quasi-elastic neutrino charged-current scattering on argon are analyzed. We calculate these cross sections using the relativistic distorted-wave impulse approximation and compare with recent MicroBooNE data. We found that the measured cross sections can be described well within the experimental uncertainties with value of the nucleon axial mass $1 < M_A < 1.2$ GeV. The contribution of the exclusive channel $\boldmath{(\nu_{\mu}, \mu p)}$ to the flux-integrated inclusive cross sections is about 50\%.
[ { "created": "Mon, 5 Jul 2021 07:24:23 GMT", "version": "v1" } ]
2022-02-23
[ [ "Butkevich", "A. V.", "" ] ]
Flux-integrated semi-exclusive differential and integral cross sections for quasi-elastic neutrino charged-current scattering on argon are analyzed. We calculate these cross sections using the relativistic distorted-wave impulse approximation and compare with recent MicroBooNE data. We found that the measured cross sections can be described well within the experimental uncertainties with value of the nucleon axial mass $1 < M_A < 1.2$ GeV. The contribution of the exclusive channel $\boldmath{(\nu_{\mu}, \mu p)}$ to the flux-integrated inclusive cross sections is about 50\%.
0711.0950
Harmen J. Warringa
Dmitri E. Kharzeev, Larry D. McLerran, Harmen J. Warringa
The effects of topological charge change in heavy ion collisions: "Event by event P and CP violation"
33 pages, 7 figures
Nucl.Phys.A803:227-253,2008
10.1016/j.nuclphysa.2008.02.298
null
hep-ph nucl-ex nucl-th
null
Quantum chromodynamics (QCD) contains field configurations which can be characterized by a topological invariant, the winding number Q_w. Configurations with nonzero Q_w break the charge-parity CP symmetry of QCD. We consider a novel mechanism by which these configurations can separate charge in the presence of a background magnetic field - the "Chiral Magnetic Effect". We argue that sufficiently large magnetic fields are created in heavy ion collisions so that the Chiral Magnetic Effect causes preferential emission of charged particles along the direction of angular momentum. Since separation of charge is CP-odd, any observation of the Chiral Magnetic Effect could provide a clear demonstration of the topological nature of the QCD vacuum. We give an estimate of the effect and conclude that it might be observed experimentally.
[ { "created": "Tue, 6 Nov 2007 19:00:09 GMT", "version": "v1" } ]
2010-04-06
[ [ "Kharzeev", "Dmitri E.", "" ], [ "McLerran", "Larry D.", "" ], [ "Warringa", "Harmen J.", "" ] ]
Quantum chromodynamics (QCD) contains field configurations which can be characterized by a topological invariant, the winding number Q_w. Configurations with nonzero Q_w break the charge-parity CP symmetry of QCD. We consider a novel mechanism by which these configurations can separate charge in the presence of a background magnetic field - the "Chiral Magnetic Effect". We argue that sufficiently large magnetic fields are created in heavy ion collisions so that the Chiral Magnetic Effect causes preferential emission of charged particles along the direction of angular momentum. Since separation of charge is CP-odd, any observation of the Chiral Magnetic Effect could provide a clear demonstration of the topological nature of the QCD vacuum. We give an estimate of the effect and conclude that it might be observed experimentally.
2402.06723
Wouter Dekens
Maria Dawid, Vincenzo Cirigliano, Wouter Dekens
One-loop analysis of $\beta$ decays in SMEFT
25 pages, 2 figures
null
null
INT-PUB-24-004
hep-ph
http://creativecommons.org/licenses/by/4.0/
We perform a loop-level analysis of charged-current (CC) processes involving light leptons and quarks within the Standard Model Effective Field Theory (SMEFT). This work is motivated by the high precision reached in experiment and Standard Model calculations for CC decays of mesons, neutron, and nuclei, and by a lingering tension in the Cabibbo universality test. We identify the SMEFT operators that induce the largest loop-level contributions to CC processes. These include four-quark and four-fermion semileptonic operators involving two third-generation quarks. We discuss the available constraints on the relevant effective couplings and along the way we derive new loop-level bounds from $K \to \pi \nu \bar \nu$ on four-quark operators involving two top quarks. We find that low-energy CC processes are quite competitive with other probes, set constraints that do not depend on flavor-symmetry assumptions, and probe operators involving third-generation quarks up to effective scales of $\Lambda\simeq 8$ TeV. Finally, we briefly discuss single-field ultraviolet completions that could induce the relevant operators.
[ { "created": "Fri, 9 Feb 2024 19:00:03 GMT", "version": "v1" } ]
2024-02-13
[ [ "Dawid", "Maria", "" ], [ "Cirigliano", "Vincenzo", "" ], [ "Dekens", "Wouter", "" ] ]
We perform a loop-level analysis of charged-current (CC) processes involving light leptons and quarks within the Standard Model Effective Field Theory (SMEFT). This work is motivated by the high precision reached in experiment and Standard Model calculations for CC decays of mesons, neutron, and nuclei, and by a lingering tension in the Cabibbo universality test. We identify the SMEFT operators that induce the largest loop-level contributions to CC processes. These include four-quark and four-fermion semileptonic operators involving two third-generation quarks. We discuss the available constraints on the relevant effective couplings and along the way we derive new loop-level bounds from $K \to \pi \nu \bar \nu$ on four-quark operators involving two top quarks. We find that low-energy CC processes are quite competitive with other probes, set constraints that do not depend on flavor-symmetry assumptions, and probe operators involving third-generation quarks up to effective scales of $\Lambda\simeq 8$ TeV. Finally, we briefly discuss single-field ultraviolet completions that could induce the relevant operators.
hep-ph/0108106
Marek Karliner
Marek Karliner (Tel-Aviv University)
A possible resolution of the e+e- --> Nbar N puzzle
Invited talk at the workshop "e+e- Physics at Intermediate Energies", SLAC, April 30 - May 2, 2001; paper No. W10; 6 pages, 6 figures
eConf C010430 (2001) W10
null
null
hep-ph
null
We sketch some recent ideas proposed as the mechanism behind the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to threshold. The essential new point in the proposed mechanism is that it is a two-stage process, with a coherent state of pions serving as an intermediary between e+e- and the baryon-antibaryon system. Skyrmion-antiskyrmion annihilation is proposed as a concrete computational framework for a quantitative description of the baryon-antibaryon annihilation. We also point out the possible connection to similarly puzzling data on baryon-antibaryon production in photon-photon collision.
[ { "created": "Sun, 12 Aug 2001 20:05:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Karliner", "Marek", "", "Tel-Aviv University" ] ]
We sketch some recent ideas proposed as the mechanism behind the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to threshold. The essential new point in the proposed mechanism is that it is a two-stage process, with a coherent state of pions serving as an intermediary between e+e- and the baryon-antibaryon system. Skyrmion-antiskyrmion annihilation is proposed as a concrete computational framework for a quantitative description of the baryon-antibaryon annihilation. We also point out the possible connection to similarly puzzling data on baryon-antibaryon production in photon-photon collision.
hep-ph/0702193
Michael Gronau
Michael Gronau and Jonathan L. Rosner
Isospin of new physics in $|\Delta S|=1$ charmless B decays
22 pages, to be published in Phys. Rev. D
Phys.Rev.D75:094006,2007
10.1103/PhysRevD.75.094006
EFI 07-06, TECHNION-PH-2007-05
hep-ph hep-ex
null
New physics (NP) in charmless strangeness-changing $B$ and $B_s$ decays, which are dominated by the $b \to s$ penguin amplitudes, can either preserve isospin or change it by one unit. A general formalism is presented studying pairs of processes related to each other by isospin reflection. We discuss information on $\Delta I$ in NP amplitudes, provided by time-integrated CP-violating rate asymmetries in $B^+$ and $B^0$ decays (or in $B_s$ decays), differences between rates for isospin-reflected processes, and coefficients $S$ of $\sin \Delta m t$ in time-dependent CP asymmetries. These four asymmetries in $B^+$ and $B^0$ decays (or five asymmetries in $B_s$ decays) are shown to determine the magnitude and CP-violating phase of a potential isovector NP amplitude, and the imaginary part of an isoscalar amplitude, assuming that strong phases in NP amplitudes are negligible. This information may be compared with predictions of specific models, for which we discuss a few examples.
[ { "created": "Mon, 19 Feb 2007 18:08:46 GMT", "version": "v1" }, { "created": "Thu, 22 Feb 2007 20:41:59 GMT", "version": "v2" }, { "created": "Tue, 27 Feb 2007 10:38:57 GMT", "version": "v3" }, { "created": "Wed, 28 Feb 2007 20:14:50 GMT", "version": "v4" }, { "c...
2008-11-26
[ [ "Gronau", "Michael", "" ], [ "Rosner", "Jonathan L.", "" ] ]
New physics (NP) in charmless strangeness-changing $B$ and $B_s$ decays, which are dominated by the $b \to s$ penguin amplitudes, can either preserve isospin or change it by one unit. A general formalism is presented studying pairs of processes related to each other by isospin reflection. We discuss information on $\Delta I$ in NP amplitudes, provided by time-integrated CP-violating rate asymmetries in $B^+$ and $B^0$ decays (or in $B_s$ decays), differences between rates for isospin-reflected processes, and coefficients $S$ of $\sin \Delta m t$ in time-dependent CP asymmetries. These four asymmetries in $B^+$ and $B^0$ decays (or five asymmetries in $B_s$ decays) are shown to determine the magnitude and CP-violating phase of a potential isovector NP amplitude, and the imaginary part of an isoscalar amplitude, assuming that strong phases in NP amplitudes are negligible. This information may be compared with predictions of specific models, for which we discuss a few examples.
1808.01419
Xin-Qiang Li
Quan-Yi Hu, Xin-Qiang Li, Yu Muramatsu, and Ya-Dong Yang
R-parity violating solutions to the $R_{D^{(\ast)}}$ anomaly and their GUT-scale unifications
21 pages, 2 tables, 6 figures; more discussions and references added, final version to be published in PRD
Phys. Rev. D 99, 015008 (2019)
10.1103/PhysRevD.99.015008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, several $B$-physics experiments report interesting anomalies in the semi-leptonic decays of $B$-mesons, such as the excess in the $R_{D^{(\ast)}}$ measurements. These anomalies seem to suggest intriguing hints of lepton flavor non-universality, and the R-parity violating (RPV) interactions are candidates for explaining this non-universality. In this paper, we discuss the RPV interactions for resolving the $R_{D^{(\ast)}}$ anomaly with the Grand Unified Theory (GUT) assumption. To solve the $R_{D^{(\ast)}}$ anomaly, it is known that large RPV couplings and around $1~{\rm TeV}$ sfermion masses are required. At the same time, large RPV couplings are conducive to realize the bottom-tau Yukawa unification which appears in the GUT models. On the other hand, there are problems for realizing favorable sfermion masses in the constrained minimal supersymetric standard model. To resolve these problems, we show that two non-universalities, the non-universal sfermion masses and the non-universal gaugino masses, are favorable.
[ { "created": "Sat, 4 Aug 2018 03:47:42 GMT", "version": "v1" }, { "created": "Fri, 4 Jan 2019 06:27:45 GMT", "version": "v2" } ]
2019-01-09
[ [ "Hu", "Quan-Yi", "" ], [ "Li", "Xin-Qiang", "" ], [ "Muramatsu", "Yu", "" ], [ "Yang", "Ya-Dong", "" ] ]
Recently, several $B$-physics experiments report interesting anomalies in the semi-leptonic decays of $B$-mesons, such as the excess in the $R_{D^{(\ast)}}$ measurements. These anomalies seem to suggest intriguing hints of lepton flavor non-universality, and the R-parity violating (RPV) interactions are candidates for explaining this non-universality. In this paper, we discuss the RPV interactions for resolving the $R_{D^{(\ast)}}$ anomaly with the Grand Unified Theory (GUT) assumption. To solve the $R_{D^{(\ast)}}$ anomaly, it is known that large RPV couplings and around $1~{\rm TeV}$ sfermion masses are required. At the same time, large RPV couplings are conducive to realize the bottom-tau Yukawa unification which appears in the GUT models. On the other hand, there are problems for realizing favorable sfermion masses in the constrained minimal supersymetric standard model. To resolve these problems, we show that two non-universalities, the non-universal sfermion masses and the non-universal gaugino masses, are favorable.
0907.1577
Robert Shrock
Shmuel Nussinov and Robert Shrock
Gluon-Glueball Duality and Glueball Searches
10 pages, latex
Phys.Rev.D80:054003,2009
10.1103/PhysRevD.80.054003
TU-CU-SUNY preprint (YITP-SB-09-15)
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a notion of gluon-glueball duality analogous to quark-hadron duality. We apply this idea to the radiative decay of heavy orthoquarkonium, $Q\bar Q \to \gamma g g$, which has been used to search for glueballs. The duality is first introduced in two simplified contexts: (i) a hypothetical version of QCD without any light quarks and (ii) QCD in the large-$N_c$ limit. We then discuss how an approximate form of this duality could hold in real QCD, based on a hierarchy of time scales in the temporal evolution of the $gg$ subsystem in radiative orthoquarkonium decay. We apply this notion of gluon-glueball duality to suggest a method that could be useful in experimental searches for glueballs.
[ { "created": "Thu, 9 Jul 2009 14:44:51 GMT", "version": "v1" } ]
2009-09-24
[ [ "Nussinov", "Shmuel", "" ], [ "Shrock", "Robert", "" ] ]
We discuss a notion of gluon-glueball duality analogous to quark-hadron duality. We apply this idea to the radiative decay of heavy orthoquarkonium, $Q\bar Q \to \gamma g g$, which has been used to search for glueballs. The duality is first introduced in two simplified contexts: (i) a hypothetical version of QCD without any light quarks and (ii) QCD in the large-$N_c$ limit. We then discuss how an approximate form of this duality could hold in real QCD, based on a hierarchy of time scales in the temporal evolution of the $gg$ subsystem in radiative orthoquarkonium decay. We apply this notion of gluon-glueball duality to suggest a method that could be useful in experimental searches for glueballs.
hep-ph/0501005
Alexander Andrianov
A. A. Andrianov (1,2), V. A. Andrianov (2)((1) INFN Bologna, (2) St.Petersburg State University)
Quasilocal Quark Models as Effective Theory of Non-perturbative QCD
5 pages, Talk at the International Symposium "MENU 2004", 29.August-4.September, Beijing,China
Int.J.Mod.Phys. A20 (2005) 1850-1854
10.1142/S0217751X05023475
null
hep-ph nucl-th
null
We consider the Quasilocal Quark Model of NJL type (QNJLM) as an effective theory of non-perturbative QCD including scalar (S), pseudoscalar (P), vector (V) and axial-vector (A) four-fermion interaction with derivatives. In the presence of a strong attraction in the scalar channel the chiral symmetry is spontaneously broken and as a consequence the composite meson states are generated in all channels. With the help of Operator Product Expansion the appropriate set of Chiral Symmetry Restoration (CSR) Sum Rules in these channels are imposed as matching conditions to QCD at intermediate energies. The mass spectrum and some decay constants for ground and excited meson states are calculated.
[ { "created": "Sun, 2 Jan 2005 13:45:24 GMT", "version": "v1" } ]
2009-11-11
[ [ "Andrianov", "A. A.", "" ], [ "Andrianov", "V. A.", "" ] ]
We consider the Quasilocal Quark Model of NJL type (QNJLM) as an effective theory of non-perturbative QCD including scalar (S), pseudoscalar (P), vector (V) and axial-vector (A) four-fermion interaction with derivatives. In the presence of a strong attraction in the scalar channel the chiral symmetry is spontaneously broken and as a consequence the composite meson states are generated in all channels. With the help of Operator Product Expansion the appropriate set of Chiral Symmetry Restoration (CSR) Sum Rules in these channels are imposed as matching conditions to QCD at intermediate energies. The mass spectrum and some decay constants for ground and excited meson states are calculated.
hep-ph/0402002
Stephen D. H. Hsu
D.K. Hong and S.D.H. Hsu
The Fermion Sign Problem and High Density Effective Theory
Contribution to proceedings of KIAS-APCTP Symposium on Astro-Hadron Physics, published by World Scientific. Based on talk by S. Hsu
null
10.1142/9789812702524_0019
null
hep-ph hep-lat hep-th nucl-th
null
We investigate the positivity of the Euclidean path integral measure for low-energy modes in dense fermionic matter. We show that the sign problem usually associated with fermions is absent if one considers only low-energy degrees of freedom. We describe a method for simulating dense QCD on the lattice and give a proof using rigorous inequalities that the color-flavor locked (CFL) phase is the true vacuum of three flavor, massless QCD.
[ { "created": "Fri, 30 Jan 2004 22:54:46 GMT", "version": "v1" } ]
2017-08-23
[ [ "Hong", "D. K.", "" ], [ "Hsu", "S. D. H.", "" ] ]
We investigate the positivity of the Euclidean path integral measure for low-energy modes in dense fermionic matter. We show that the sign problem usually associated with fermions is absent if one considers only low-energy degrees of freedom. We describe a method for simulating dense QCD on the lattice and give a proof using rigorous inequalities that the color-flavor locked (CFL) phase is the true vacuum of three flavor, massless QCD.
1709.02571
Fu-Sheng Yu
Fu-Sheng Yu
Weak-decay searches for $Qs\bar u\bar d$ tetraquarks
5 pages, 4 figures
Eur.Phys.J.C 82, 641 (2022)
10.1140/epjc/s10052-022-10567-8
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose to search for the open heavy-flavor exotic states with the quark components of $Qs\bar u\bar d$ with $Q=b,c$ via their weak decays. If there exist such exotic states below the $BK$ or $DK$ thresholds, they can only decay weakly. The advantages include: (i) the experimental backgrounds from the secondary decay vertex are much lower due to the long lifetimes, (ii) the productions are large enough for only one heavy quark in such states, (iii) the thresholds of $BK$ or $DK$ are about 260 MeV higher compared to the $B_s\pi$ or $D_s\pi$ thresholds of the configurations of $Qu\bar s\bar d$ or $Qd\bar s\bar u$ , with a higher possibility to exist such weakly-decay particles, and (iv) if observed, their inner structures are easier understood since they can not be induced by the kinematic effects.
[ { "created": "Fri, 8 Sep 2017 07:10:27 GMT", "version": "v1" }, { "created": "Mon, 28 Mar 2022 16:55:08 GMT", "version": "v2" }, { "created": "Tue, 26 Jul 2022 22:30:06 GMT", "version": "v3" } ]
2022-07-28
[ [ "Yu", "Fu-Sheng", "" ] ]
We propose to search for the open heavy-flavor exotic states with the quark components of $Qs\bar u\bar d$ with $Q=b,c$ via their weak decays. If there exist such exotic states below the $BK$ or $DK$ thresholds, they can only decay weakly. The advantages include: (i) the experimental backgrounds from the secondary decay vertex are much lower due to the long lifetimes, (ii) the productions are large enough for only one heavy quark in such states, (iii) the thresholds of $BK$ or $DK$ are about 260 MeV higher compared to the $B_s\pi$ or $D_s\pi$ thresholds of the configurations of $Qu\bar s\bar d$ or $Qd\bar s\bar u$ , with a higher possibility to exist such weakly-decay particles, and (iv) if observed, their inner structures are easier understood since they can not be induced by the kinematic effects.
hep-ph/0206294
Cristian Villavicencio
M. Loewe and C. Villavicencio
Thermal Pions ns Isospin Chemical Potential Effects
5 pages, 2 figures. To appear in the proceedings of the International High-Energy Physics Conference on Quantum Chromodynamics QCD02, Montpellier, 2-9 July (2002)
null
10.1016/S0920-5632(03)01864-4
UCCHEP/ 20-02
hep-ph
null
The density corrections, in terms of the isospin chemical potential $\mu_I$, to the mass of the pions are investigated in the framework of the SU(2) low energy effective chiral invariant lagrangian. As a function of temperature and $\mu_I =0$, the mass remains quite stable, starting to grow for very high values of $T$, confirming previous results. However, the dependence for a non-vanishing chemical potential turns out to be much more dramatic. In particular, there are interesting corrections to the mass when both effects (temperature and chemical potential) are simultaneously present. At zero temperature the $\pi ^{\pm}$ should condensate when $\mu_{I} = \mp m_{\pi}$. This is not longer valid anymore at finite $T$. The mass of the $\pi_0$ acquires also a non trivial dependence on $\mu_I$ at finite $T$.
[ { "created": "Thu, 27 Jun 2002 22:21:44 GMT", "version": "v1" }, { "created": "Tue, 24 Sep 2002 18:57:44 GMT", "version": "v2" } ]
2009-11-07
[ [ "Loewe", "M.", "" ], [ "Villavicencio", "C.", "" ] ]
The density corrections, in terms of the isospin chemical potential $\mu_I$, to the mass of the pions are investigated in the framework of the SU(2) low energy effective chiral invariant lagrangian. As a function of temperature and $\mu_I =0$, the mass remains quite stable, starting to grow for very high values of $T$, confirming previous results. However, the dependence for a non-vanishing chemical potential turns out to be much more dramatic. In particular, there are interesting corrections to the mass when both effects (temperature and chemical potential) are simultaneously present. At zero temperature the $\pi ^{\pm}$ should condensate when $\mu_{I} = \mp m_{\pi}$. This is not longer valid anymore at finite $T$. The mass of the $\pi_0$ acquires also a non trivial dependence on $\mu_I$ at finite $T$.
1608.01650
Masato Yamanaka
Yoshio Koide and Masato Yamanaka
Muon-Electron Conversion in a Family Gauge Boson Model
14 pages, 3 figures
null
10.1016/j.physletb.2016.09.004
MISC-2016-07
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $\mu$-$e$ conversion in muonic atoms via an exchange of family gauge boson (FGB) $A_{2}^{\ 1}$ in a $U(3)$ FGB model. Within the class of FGB model, we consider three types of family-number assignments for quarks. We evaluate the $\mu$-$e$ conversion rate for various target nuclei, and find that next generation $\mu$-$e$ conversion search experiments can cover entire energy scale of the model for all of types of the quark family-number assignments. We show that the conversion rate in the model is so sensitive to up- and down-quark mixing matrices, $U^{u}$ and $U^{d}$, where the CKM matrix is given by $V_\text{CKM} = U^{u\dagger} U^d$. Precise measurements of conversion rates for various target nuclei can identify not only the types of quark family-number assignments, but also each quark mixing matrix individually.
[ { "created": "Thu, 4 Aug 2016 19:35:29 GMT", "version": "v1" } ]
2016-09-07
[ [ "Koide", "Yoshio", "" ], [ "Yamanaka", "Masato", "" ] ]
We study the $\mu$-$e$ conversion in muonic atoms via an exchange of family gauge boson (FGB) $A_{2}^{\ 1}$ in a $U(3)$ FGB model. Within the class of FGB model, we consider three types of family-number assignments for quarks. We evaluate the $\mu$-$e$ conversion rate for various target nuclei, and find that next generation $\mu$-$e$ conversion search experiments can cover entire energy scale of the model for all of types of the quark family-number assignments. We show that the conversion rate in the model is so sensitive to up- and down-quark mixing matrices, $U^{u}$ and $U^{d}$, where the CKM matrix is given by $V_\text{CKM} = U^{u\dagger} U^d$. Precise measurements of conversion rates for various target nuclei can identify not only the types of quark family-number assignments, but also each quark mixing matrix individually.
1011.5790
Sven-Olaf Moch
S. Alekhin and S. Moch
Heavy-quark deep-inelastic scattering with a running mass
16 pages Latex, 8 figures
null
10.1016/j.physletb.2011.04.026
DESY 10-212
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production of heavy quarks in deep-inelastic scattering within perturbative QCD. As a novelty, we employ for the first time the running mass definition in the MSbar scheme for deep-inelastic charm and bottom production. We observe an improved stability of the perturbative expansion and a reduced theoretical uncertainty due to variations of the renormalization and factorization scales. As our best estimate we extract from a global fit to fixed-target and HERA collider data for the charm-quark an MSbar mass of m_c(m_c) = 1.01 +- 0.09 (exp) +- 0.03 (th) GeV.
[ { "created": "Fri, 26 Nov 2010 14:05:34 GMT", "version": "v1" } ]
2015-05-20
[ [ "Alekhin", "S.", "" ], [ "Moch", "S.", "" ] ]
We study the production of heavy quarks in deep-inelastic scattering within perturbative QCD. As a novelty, we employ for the first time the running mass definition in the MSbar scheme for deep-inelastic charm and bottom production. We observe an improved stability of the perturbative expansion and a reduced theoretical uncertainty due to variations of the renormalization and factorization scales. As our best estimate we extract from a global fit to fixed-target and HERA collider data for the charm-quark an MSbar mass of m_c(m_c) = 1.01 +- 0.09 (exp) +- 0.03 (th) GeV.
2107.13748
Ning Li
Ning Li, Zhi-Feng Sun, Xiang Liu, and Shi-Lin Zhu
Perfect $DD^*$ molecular prediction matching the $T_{cc}$ observation at LHCb
2 pages, 2 figures
Chin. Phys. Lett. 38, 092001 (2021)
10.1088/0256-307X/38/9/092001
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In 2012, we investigated the possible molecular states composed of two charmed mesons [Phys.Rev. D 88, 114008 (2013), arXiv:1211.5007 [hep-ph](2012)]. The $D^*D$ system with the quantum numbers of $I(J^P)=0(1^+)$ was found to be a good candidate of the loosely bound molecular state. This state is very close to the $D^*D$ threshold with a binding energy around 0.47 MeV. This prediction was confirmed by the new LHCb observation of $T_{cc}^+$ [see Franz Muheim's talk at the European Physical Society conference on high energy physics 2021].
[ { "created": "Thu, 29 Jul 2021 05:06:27 GMT", "version": "v1" }, { "created": "Sun, 1 Aug 2021 03:08:33 GMT", "version": "v2" }, { "created": "Tue, 3 Aug 2021 08:09:13 GMT", "version": "v3" }, { "created": "Sun, 15 Aug 2021 03:07:05 GMT", "version": "v4" }, { "cre...
2021-09-07
[ [ "Li", "Ning", "" ], [ "Sun", "Zhi-Feng", "" ], [ "Liu", "Xiang", "" ], [ "Zhu", "Shi-Lin", "" ] ]
In 2012, we investigated the possible molecular states composed of two charmed mesons [Phys.Rev. D 88, 114008 (2013), arXiv:1211.5007 [hep-ph](2012)]. The $D^*D$ system with the quantum numbers of $I(J^P)=0(1^+)$ was found to be a good candidate of the loosely bound molecular state. This state is very close to the $D^*D$ threshold with a binding energy around 0.47 MeV. This prediction was confirmed by the new LHCb observation of $T_{cc}^+$ [see Franz Muheim's talk at the European Physical Society conference on high energy physics 2021].
1308.1368
Danny Marfatia
Jiajun Liao, Danny Marfatia, Kerry Whisnant
Dual models of the neutrino mass spectrum
12 pages, 1 eps figure. Version to appear in PRD
Phys. Rev. D 89, 013009 (2014)
10.1103/PhysRevD.89.013009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that any model with a homogeneous relationship among elements of the neutrino mass matrix with one mass hierarchy yields predictions for the oscillation parameters and Majorana phases similar to those given by a model with the same homogeneous relationship among cofactors of the neutrino mass matrix with the opposite mass hierarchy, except when the lightest mass is of order 20 meV or less.
[ { "created": "Tue, 6 Aug 2013 18:27:10 GMT", "version": "v1" }, { "created": "Fri, 10 Jan 2014 18:29:57 GMT", "version": "v2" } ]
2014-01-29
[ [ "Liao", "Jiajun", "" ], [ "Marfatia", "Danny", "" ], [ "Whisnant", "Kerry", "" ] ]
We show that any model with a homogeneous relationship among elements of the neutrino mass matrix with one mass hierarchy yields predictions for the oscillation parameters and Majorana phases similar to those given by a model with the same homogeneous relationship among cofactors of the neutrino mass matrix with the opposite mass hierarchy, except when the lightest mass is of order 20 meV or less.
hep-ph/0406124
Khamidbi Beshtoev Mukhamedovich
Kh. M. Beshtoev
Schemes of Neutrino Mixings (Oscillations) and Their Mixing Matrices
LATEX, 13 pages, no figures and tables
null
null
JINR Communication E2-2004-58, Dubna, 2004
hep-ph
null
Three schemes of neutrino mixings (oscillations) together with their mixing matrices (analogous to Kabibbo-Kobayashi-Maskawa matrices) are considered. In these schemes neutrino transitions are virtual if neutrino masses are different. Two of them belong to the so called mass mixing schemes (mixing parameters are expressed by elements of mass matrices) and the third scheme belongs to the charge mixing scheme (mixing parameters are expressed through charges). In the first scheme system of 6 equations for determination of the all elements of the mass matrix (neutrino masses and transition widths) by using experimental data are obtained. In the second and third ones the neutrino mixing angles are equal or close to maximal angles ($\pi/4$). It is obvious that the experiment must give an answer to the following question: Which of these schemes is realized indeed?
[ { "created": "Thu, 10 Jun 2004 15:16:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Beshtoev", "Kh. M.", "" ] ]
Three schemes of neutrino mixings (oscillations) together with their mixing matrices (analogous to Kabibbo-Kobayashi-Maskawa matrices) are considered. In these schemes neutrino transitions are virtual if neutrino masses are different. Two of them belong to the so called mass mixing schemes (mixing parameters are expressed by elements of mass matrices) and the third scheme belongs to the charge mixing scheme (mixing parameters are expressed through charges). In the first scheme system of 6 equations for determination of the all elements of the mass matrix (neutrino masses and transition widths) by using experimental data are obtained. In the second and third ones the neutrino mixing angles are equal or close to maximal angles ($\pi/4$). It is obvious that the experiment must give an answer to the following question: Which of these schemes is realized indeed?
1604.01008
Gabor Cynolter
G.Cynolter, J . Kov\'acs and E.Lendvai
Diphoton excess and VV-scattering
10 pages, 2 Latex figures, v2 typos corrected, references added, published version
null
10.1142/S0217732316501339
ITP-Budapest 668
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider minimal effective interactions of the 750 GeV mass resonance observed recently by ATLAS and CMS. Assuming a new scalar and gauge invariant effective interactions leads to non-trivial two particle scattering amplitudes with asymptotic gauge boson states. The longitudinally polarized $W\pm$ and $Z$ bosons interacting via dimension-five effective operators provide stringent constraints on the validity of the effective model. The large width found by ATLAS implying a bound of approximately 500 GeV already below the resonance, turns this scenario unlikely. For production mainly in gluon fusion we get an upper bound of $\sim 1.3$ TeV and strong limits on the masses of the underlying vector-like fermions are given.
[ { "created": "Mon, 4 Apr 2016 19:57:58 GMT", "version": "v1" }, { "created": "Mon, 11 Jul 2016 13:09:45 GMT", "version": "v2" } ]
2016-07-12
[ [ "Cynolter", "G.", "" ], [ "Kovács", "J .", "" ], [ "Lendvai", "E.", "" ] ]
We consider minimal effective interactions of the 750 GeV mass resonance observed recently by ATLAS and CMS. Assuming a new scalar and gauge invariant effective interactions leads to non-trivial two particle scattering amplitudes with asymptotic gauge boson states. The longitudinally polarized $W\pm$ and $Z$ bosons interacting via dimension-five effective operators provide stringent constraints on the validity of the effective model. The large width found by ATLAS implying a bound of approximately 500 GeV already below the resonance, turns this scenario unlikely. For production mainly in gluon fusion we get an upper bound of $\sim 1.3$ TeV and strong limits on the masses of the underlying vector-like fermions are given.
hep-ph/0108047
Butkevich
L. B. Bezrukov and A. V. Butkevich
Fast simulation of the Cherenkov light from showers
15 pages, 6 figures, submitted to Nucl. Instrum. and Methods
null
null
null
hep-ph
null
A method for fast simulation of the Cherenkov light generated by electromagnetic showers is described. The parametrization for the longitudinal profile is used and fluctuations and correlations of the parameters are taken into account in a consistent way. Our method dramatically reduces the CPU time and its results are in a rather good agreement with a full Monte Carlo simulation.
[ { "created": "Sun, 5 Aug 2001 06:14:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bezrukov", "L. B.", "" ], [ "Butkevich", "A. V.", "" ] ]
A method for fast simulation of the Cherenkov light generated by electromagnetic showers is described. The parametrization for the longitudinal profile is used and fluctuations and correlations of the parameters are taken into account in a consistent way. Our method dramatically reduces the CPU time and its results are in a rather good agreement with a full Monte Carlo simulation.
1005.4183
Harry Lipkin J
Harry J. Lipkin
Why do neutrinos with different masses interfere and oscillate? Why are states with different masses but same energy coherent? Overcoming barrier between particle & condensed matter physics
16 pages, no figures, new title and abstract clarification of previous version
null
null
null
hep-ph physics.ins-det quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino oscillations occur only if it is impossible to determine $\nu$ mass by using conservation laws on measurements of nucleon-lepton system absorbing $\nu$. No oscillations if $\nu$ detector is mass spectrometer. Beam is split into components with different masses entering different counters. For each event only one counter will click and determine $\nu$ mass. Condensed matter physics needed to describe the $\nu$ detector, show it is not a mass spectrometer and identify which properties of the incident $\nu$ are unobservable. Relativistic quantum field theory can only describe $\nu$ wave function entering detector but not large uncertain momentum transfers to detector nor associated energy-momentum asymmetry. Absorption of incident $\nu$'s with different momenta but same energy leaves no trace of initial $\nu$ momentum difference in finite-size $\nu$ detector with effectively infinite mass at rest in laboratory. Undetectable recoil-free momentum is transferred to the detector with negligible energy transfer. The Debye-Waller factor common in X-ray diffraction by crystals gives probability that absorbing $\nu$'s with different momenta produce same nucleon-charged-lepton final state. Oscillations in time described in textbooks as interference between $\nu$ states with different energies not observable in realistic experiments. Different energy $\nu$'s not coherent because energy can be determined by measurements on initial and final states. Experiments detecting $\nu$ produced by $\pi to \mu \nu$ decay observe no electrons even though $\nu$ mass eigenstates produce electrons. Electron amplitude canceled by interference between amplitudes from different $\nu$ mass eigenstates with same energy and different momenta entering massive detector.
[ { "created": "Sun, 23 May 2010 09:31:28 GMT", "version": "v1" }, { "created": "Wed, 27 Jul 2011 16:20:19 GMT", "version": "v2" }, { "created": "Sun, 7 Aug 2011 18:42:35 GMT", "version": "v3" }, { "created": "Sun, 4 Dec 2011 10:34:24 GMT", "version": "v4" }, { "cre...
2012-07-25
[ [ "Lipkin", "Harry J.", "" ] ]
Neutrino oscillations occur only if it is impossible to determine $\nu$ mass by using conservation laws on measurements of nucleon-lepton system absorbing $\nu$. No oscillations if $\nu$ detector is mass spectrometer. Beam is split into components with different masses entering different counters. For each event only one counter will click and determine $\nu$ mass. Condensed matter physics needed to describe the $\nu$ detector, show it is not a mass spectrometer and identify which properties of the incident $\nu$ are unobservable. Relativistic quantum field theory can only describe $\nu$ wave function entering detector but not large uncertain momentum transfers to detector nor associated energy-momentum asymmetry. Absorption of incident $\nu$'s with different momenta but same energy leaves no trace of initial $\nu$ momentum difference in finite-size $\nu$ detector with effectively infinite mass at rest in laboratory. Undetectable recoil-free momentum is transferred to the detector with negligible energy transfer. The Debye-Waller factor common in X-ray diffraction by crystals gives probability that absorbing $\nu$'s with different momenta produce same nucleon-charged-lepton final state. Oscillations in time described in textbooks as interference between $\nu$ states with different energies not observable in realistic experiments. Different energy $\nu$'s not coherent because energy can be determined by measurements on initial and final states. Experiments detecting $\nu$ produced by $\pi to \mu \nu$ decay observe no electrons even though $\nu$ mass eigenstates produce electrons. Electron amplitude canceled by interference between amplitudes from different $\nu$ mass eigenstates with same energy and different momenta entering massive detector.
0904.2124
Rohit Dhir
Rohit Dhir and R.C. Verma
Magnetic Moments of $J^P=3/2^+$ Heavy Baryons Using Effective Mass and Screened Charge Scheme
19 pages, Accepted for publication in EPJ-A
Eur.Phys.J.A42:243-249,2009
10.1140/epja/i2009-10872-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Magnetic moments of heavy charmed baryons with $J^P=3/2^+$ are predicted employing the concept of effective quark mass and screened charge of quark. We also extend our scheme to predict the $3/2^+ --> 1/2^+$ transition magnetic moments. A comparison of our results with the predictions obtained in recent models is presented.
[ { "created": "Tue, 14 Apr 2009 13:57:31 GMT", "version": "v1" }, { "created": "Mon, 21 Sep 2009 05:53:33 GMT", "version": "v2" } ]
2009-11-19
[ [ "Dhir", "Rohit", "" ], [ "Verma", "R. C.", "" ] ]
Magnetic moments of heavy charmed baryons with $J^P=3/2^+$ are predicted employing the concept of effective quark mass and screened charge of quark. We also extend our scheme to predict the $3/2^+ --> 1/2^+$ transition magnetic moments. A comparison of our results with the predictions obtained in recent models is presented.
1010.3974
Hua-Xing Chen
Hua-Xing Chen, Zi-Xing Cai, Peng-Zhi Huang and Shi-Lin Zhu
The Decay Properties of the 1^{-+} Hybrid State
one reference corrected
Phys.Rev.D83:014006,2011
10.1103/PhysRevD.83.014006
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the framework of the QCD sum rules, we consider the three-point correlation function, work at the limit q^2 -> 0 and m_\pi -> 0, and pick out the singular term ~ {1\over q^2} to extract the pionic coupling constants of the 1^{-+} hybrid meson. Then we calculate the decay widths of different modes. The decay width of the S-wave modes b_1 \pi, f_1\pi increases quickly as the hybrid meson mass and decay momentum increase. But for the low mass hybrid meson around 1.6 GeV, the P-wave decay mode \rho \pi is very important and its width is around 180 MeV, while the widths of \eta \pi and \eta^\prime \pi are strongly suppressed. We suggest the experimental search of \pi_1(1600) through the decay chains at BESIII: e^+e^- -> J/\psi(\psi') -> \pi_1 +\gamma or e^+e^- -> J/\psi(\psi') -> \pi_1 +\rho where the \pi_1 state can be reconstructed through the decay modes \pi_1 -> \rho\pi -> \pi^+\pi^-\pi^0 or \pi_1 -> f_1(1285)\pi^0. It is also interesting to look for \pi_1 using the available BELLE/BABAR data through the process e^+e^- -> \gamma^\ast -> \rho\pi_1, b_1\pi_1, \gamma \pi_1 etc.
[ { "created": "Tue, 19 Oct 2010 16:45:47 GMT", "version": "v1" }, { "created": "Wed, 22 Dec 2010 03:32:51 GMT", "version": "v2" }, { "created": "Wed, 12 Jan 2011 10:51:06 GMT", "version": "v3" }, { "created": "Fri, 29 Apr 2011 15:25:43 GMT", "version": "v4" } ]
2015-03-17
[ [ "Chen", "Hua-Xing", "" ], [ "Cai", "Zi-Xing", "" ], [ "Huang", "Peng-Zhi", "" ], [ "Zhu", "Shi-Lin", "" ] ]
Within the framework of the QCD sum rules, we consider the three-point correlation function, work at the limit q^2 -> 0 and m_\pi -> 0, and pick out the singular term ~ {1\over q^2} to extract the pionic coupling constants of the 1^{-+} hybrid meson. Then we calculate the decay widths of different modes. The decay width of the S-wave modes b_1 \pi, f_1\pi increases quickly as the hybrid meson mass and decay momentum increase. But for the low mass hybrid meson around 1.6 GeV, the P-wave decay mode \rho \pi is very important and its width is around 180 MeV, while the widths of \eta \pi and \eta^\prime \pi are strongly suppressed. We suggest the experimental search of \pi_1(1600) through the decay chains at BESIII: e^+e^- -> J/\psi(\psi') -> \pi_1 +\gamma or e^+e^- -> J/\psi(\psi') -> \pi_1 +\rho where the \pi_1 state can be reconstructed through the decay modes \pi_1 -> \rho\pi -> \pi^+\pi^-\pi^0 or \pi_1 -> f_1(1285)\pi^0. It is also interesting to look for \pi_1 using the available BELLE/BABAR data through the process e^+e^- -> \gamma^\ast -> \rho\pi_1, b_1\pi_1, \gamma \pi_1 etc.
hep-ph/9806301
Borzumati Francesca
F.M. Borzumati (Zurich Univ.), A. Djouadi (Montpellier Univ.)
Lower Bounds on Charged Higgs Bosons from LEP and the TEVATRON
9 pages, 4 figures
Phys.Lett.B549:170-176,2002
10.1016/S0370-2693(02)02889-7
ZU-TH 5/98, PM-98/1
hep-ph
null
We point out that charged Higgs bosons can decay into final states different than $\tau^+ \nu_\tau$ and $c \bar{s}$, even when they are light enough to be produced at LEPII or at the Tevatron, through top-quark decays. These additional decay modes are overlooked in ongoing searches even though they alter the existing lower bounds on the mass of charged Higgs bosons that are present in supersymmetric and two Higgs doublets models.
[ { "created": "Mon, 8 Jun 1998 11:25:19 GMT", "version": "v1" }, { "created": "Thu, 3 Oct 2002 03:18:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Borzumati", "F. M.", "", "Zurich Univ." ], [ "Djouadi", "A.", "", "Montpellier Univ." ] ]
We point out that charged Higgs bosons can decay into final states different than $\tau^+ \nu_\tau$ and $c \bar{s}$, even when they are light enough to be produced at LEPII or at the Tevatron, through top-quark decays. These additional decay modes are overlooked in ongoing searches even though they alter the existing lower bounds on the mass of charged Higgs bosons that are present in supersymmetric and two Higgs doublets models.
1403.2053
Kingman Cheung
Jung Chang, Kingman Cheung, Jae Sik Lee, and Chih-Ting Lu
Probing the Top-Yukawa Coupling in Associated Higgs production with a Single Top Quark
28 pages, 13 figures; a comment about NLO correction is added, references added; match the published version
null
10.1007/JHEP05(2014)062
CNU-HEP-14-01
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Associated production of the Higgs boson with a single top quark proceeds through Feynman diagrams, which are either proportional to the hWW, top-Yukawa, or the bottom-Yukawa couplings. It was shown in literature that the interference between the top-Yukawa and the gauge-Higgs diagrams can be significant, and thus the measurement of the cross sections can help pin down the sign and the size of the top-Yukawa coupling. Here we perform a detailed study with full detector simulations of such a possibility at the LHC-14 within the current allowed range of hWW and top-Yukawa couplings, using h-> b b-bar, \gamma\gamma, \tau+ \tau-, ZZ* -> 4 l modes. We found that the LHC-14 has the potential to distinguish the size and the sign of the top-Yukawa coupling. Among the channels the h-> b b-bar mode mode provides the best chance to probe the signal, followed by the h -> \gamma\gamma\ mode, which has the advantage of a narrow reconstructed mass peak. We also pointed out that the spatial separation among the final-state particles has the potential in differentiating among various values of the top-Yukawa coupling.
[ { "created": "Sun, 9 Mar 2014 12:29:22 GMT", "version": "v1" }, { "created": "Thu, 29 May 2014 07:07:04 GMT", "version": "v2" } ]
2015-06-19
[ [ "Chang", "Jung", "" ], [ "Cheung", "Kingman", "" ], [ "Lee", "Jae Sik", "" ], [ "Lu", "Chih-Ting", "" ] ]
Associated production of the Higgs boson with a single top quark proceeds through Feynman diagrams, which are either proportional to the hWW, top-Yukawa, or the bottom-Yukawa couplings. It was shown in literature that the interference between the top-Yukawa and the gauge-Higgs diagrams can be significant, and thus the measurement of the cross sections can help pin down the sign and the size of the top-Yukawa coupling. Here we perform a detailed study with full detector simulations of such a possibility at the LHC-14 within the current allowed range of hWW and top-Yukawa couplings, using h-> b b-bar, \gamma\gamma, \tau+ \tau-, ZZ* -> 4 l modes. We found that the LHC-14 has the potential to distinguish the size and the sign of the top-Yukawa coupling. Among the channels the h-> b b-bar mode mode provides the best chance to probe the signal, followed by the h -> \gamma\gamma\ mode, which has the advantage of a narrow reconstructed mass peak. We also pointed out that the spatial separation among the final-state particles has the potential in differentiating among various values of the top-Yukawa coupling.
0707.2855
Andrei Kataev
A.L.Kataev (INR, Moscow)
Non-planar structure of analytical QCD predictions for the Gottfried sum rule
12 pages, based on the talk at the Parralel Session of XI International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT07), April 23-27, 2007, Amsterdam; submitted to the Proceedings
PoSACAT2007:072,2007
null
null
hep-ph hep-ex hep-th
null
It is stressed that within large N_c-expansion {\bf analytical calculations} of the $(\alpha_s/\pi)^2$ QCD contributions to the valence part of the Gottfried sum rule for F_2 structure function of charged leptons-nucleon deep-inelastic scattering reveals the existence of the $O(1/N_c^2)$ {\bf non-planar} corrections only and the disappearance of the {\bf planar} O(N_c^0) perturbative terms. The relation between Gottfried and Adler sum rule for neutino-nucleon DIS is established and the proposal that the differebce between corresponding QCD corrections to higher non-singlet moments in charged-lepton and neutrino DIS are {\bf suppressed by 1/N_c^2} is made. The possible consequence of the cancellation of {\bf perturbative planar} graphs in the considered perturbative series, namely the existence of light-quark flavour asymmetry $\bar{u}(x)<\bar{d}(x)$, is mentioned. The effect of the similar origin, i.e. the relation of {\bf ``light-by-light-type''-type structure} in DIS characteristics at the $\alpha_s^3$-level to the generation of light quark-antiquark asymmetry, is also commented.
[ { "created": "Thu, 19 Jul 2007 09:16:35 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kataev", "A. L.", "", "INR, Moscow" ] ]
It is stressed that within large N_c-expansion {\bf analytical calculations} of the $(\alpha_s/\pi)^2$ QCD contributions to the valence part of the Gottfried sum rule for F_2 structure function of charged leptons-nucleon deep-inelastic scattering reveals the existence of the $O(1/N_c^2)$ {\bf non-planar} corrections only and the disappearance of the {\bf planar} O(N_c^0) perturbative terms. The relation between Gottfried and Adler sum rule for neutino-nucleon DIS is established and the proposal that the differebce between corresponding QCD corrections to higher non-singlet moments in charged-lepton and neutrino DIS are {\bf suppressed by 1/N_c^2} is made. The possible consequence of the cancellation of {\bf perturbative planar} graphs in the considered perturbative series, namely the existence of light-quark flavour asymmetry $\bar{u}(x)<\bar{d}(x)$, is mentioned. The effect of the similar origin, i.e. the relation of {\bf ``light-by-light-type''-type structure} in DIS characteristics at the $\alpha_s^3$-level to the generation of light quark-antiquark asymmetry, is also commented.
1308.3116
Igor O. Cherednikov
I.O. Cherednikov, T. Mertens, P. Taels, F.F. Van der Veken
Evolution of transverse-distance dependent parton densities at large-$x_B$ and geometry of the loop space
9 pages, 1 eps figure; needs ws-ijmpcs.cls (supplied). Invited talk presented at the QCD Evolution Workshop, May 6 -10, 2013, Thomas Jefferson National Accelerator Facility, Newport News (VA), USA
Int. J. Mod. Phys. Conf. Ser. 25 (2014) 1460006(1-9)
10.1142/S2010194514600064
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss possible applications of the equations of motion in the generalized Wilson loop space to the phenomenology of the three-dimensional parton distribution functions in the large-$x_B$ approximation. This regime is relevant for future experimental programs to be launched at the (approved) Jefferson Lab 12 GeV upgrade and the (planned) Electron-Ion Collider. We show that the geometrical evolution of the Wilson loops corresponds to the combined rapidity and renormalization-group equation of the transverse-distance dependent parton densities in the large-$x_B$ factorization scheme.
[ { "created": "Wed, 14 Aug 2013 13:24:15 GMT", "version": "v1" } ]
2014-01-09
[ [ "Cherednikov", "I. O.", "" ], [ "Mertens", "T.", "" ], [ "Taels", "P.", "" ], [ "Van der Veken", "F. F.", "" ] ]
We discuss possible applications of the equations of motion in the generalized Wilson loop space to the phenomenology of the three-dimensional parton distribution functions in the large-$x_B$ approximation. This regime is relevant for future experimental programs to be launched at the (approved) Jefferson Lab 12 GeV upgrade and the (planned) Electron-Ion Collider. We show that the geometrical evolution of the Wilson loops corresponds to the combined rapidity and renormalization-group equation of the transverse-distance dependent parton densities in the large-$x_B$ factorization scheme.
1509.08975
Meng-Ru Wu
Meng-Ru Wu, Huaiyu Duan, Yong-Zhong Qian
Physics of neutrino flavor transformation through matter-neutrino resonances
7 pages, 4 figures
Physics Letters B (2016), pp. 89-94
10.1016/j.physletb.2015.11.027
null
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.
[ { "created": "Tue, 29 Sep 2015 23:21:39 GMT", "version": "v1" } ]
2015-11-24
[ [ "Wu", "Meng-Ru", "" ], [ "Duan", "Huaiyu", "" ], [ "Qian", "Yong-Zhong", "" ] ]
In astrophysical environments such as core-collapse supernovae and neutron star-neutron star or neutron star-black hole mergers where dense neutrino media are present, matter-neutrino resonances (MNRs) can occur when the neutrino propagation potentials due to neutrino-electron and neutrino-neutrino forward scattering nearly cancel each other. We show that neutrino flavor transformation through MNRs can be explained by multiple adiabatic solutions similar to the Mikheyev-Smirnov-Wolfenstein mechanism. We find that for the normal neutrino mass hierarchy, neutrino flavor evolution through MNRs can be sensitive to the shape of neutrino spectra and the adiabaticity of the system, but such sensitivity is absent for the inverted hierarchy.
1605.00997
Chandan Mondal
Dipankar Chakrabarti and Chandan Mondal
Nucleon to $\Delta$ transition form factors and empirical transverse charge densities
9 pages, 5 figures; minor text modified, version to appear in Eur. Phys. J. A
Eur. Phys. J. A 52, 285 (2016)
10.1140/epja/i2016-16285-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the nucleon to $\Delta$ transition form factors in a soft-wall AdS/QCD model and a light-front quark-diquark model inspired by AdS/QCD. From the transition form factors we evaluate the transition charge densities which influences the nucleon to $\Delta$ excitation. Here we consider both the unpolarized and the transversely polarized cases. The AdS/QCD predictions are compared with available experimental data and with the results of the global parameterization, MAID2007.
[ { "created": "Tue, 3 May 2016 17:47:55 GMT", "version": "v1" }, { "created": "Fri, 2 Sep 2016 18:00:50 GMT", "version": "v2" } ]
2016-09-15
[ [ "Chakrabarti", "Dipankar", "" ], [ "Mondal", "Chandan", "" ] ]
We investigate the nucleon to $\Delta$ transition form factors in a soft-wall AdS/QCD model and a light-front quark-diquark model inspired by AdS/QCD. From the transition form factors we evaluate the transition charge densities which influences the nucleon to $\Delta$ excitation. Here we consider both the unpolarized and the transversely polarized cases. The AdS/QCD predictions are compared with available experimental data and with the results of the global parameterization, MAID2007.
hep-ph/9306309
Uri Sarid
Lawrence J. Hall, Riccardo Rattazzi and Uri Sarid
The Top Quark Mass in Supersymmetric SO(10) Unification
37 pages incl. 3 figures appended at bottom of file, RevTeX, [Revised, corrected & expanded] LBL-33997
Phys. Rev. D 50, 7048 (1994)
10.1103/PhysRevD.50.7048
null
hep-ph
null
The successful prediction of $\sin^2\theta_W$ suggests that the effective theory beneath the GUT scale is the two-Higgs MSSM. If we further assume that the unified gauge group contains SO(10), that the two light Higgs doublets lie mostly in a single irreducible SO(10) representation, and that the $t$, $b$ and $\tau$ masses originate in renormalizable Yukawa interactions of the form $16_3 O 16_3$, then also the top quark mass can be predicted in terms of the MSSM parameters. To compute $m_t$ we present a precise analytic approximation to the solution of the 2-loop renormalization group equations, and study supersymmetric and GUT threshold corrections and the input value of the $b$ quark mass. The large ratio of top to bottom quark masses derives from a large ratio, $\tan\beta$, of Higgs vacuum expectation values. We point out that when $\tan\beta$ is large, so are certain corrections to the $b$ quark mass prediction, unless a particular hierarchy exists in the parameters of the model. With such a hierarchy, which may result from approximate symmetries, the top mass prediction depends only weakly on the spectrum. Our results may be applied to any supersymmetric SO(10)-like model as long as $\lambda_t\simeq \lambda_b\simeq\lambda_\tau$ at the GUT scale and there are no intermediate mass scales in the desert.
[ { "created": "Thu, 24 Jun 1993 01:31:58 GMT", "version": "v1" }, { "created": "Tue, 26 Apr 1994 05:22:15 GMT", "version": "v2" } ]
2013-11-13
[ [ "Hall", "Lawrence J.", "" ], [ "Rattazzi", "Riccardo", "" ], [ "Sarid", "Uri", "" ] ]
The successful prediction of $\sin^2\theta_W$ suggests that the effective theory beneath the GUT scale is the two-Higgs MSSM. If we further assume that the unified gauge group contains SO(10), that the two light Higgs doublets lie mostly in a single irreducible SO(10) representation, and that the $t$, $b$ and $\tau$ masses originate in renormalizable Yukawa interactions of the form $16_3 O 16_3$, then also the top quark mass can be predicted in terms of the MSSM parameters. To compute $m_t$ we present a precise analytic approximation to the solution of the 2-loop renormalization group equations, and study supersymmetric and GUT threshold corrections and the input value of the $b$ quark mass. The large ratio of top to bottom quark masses derives from a large ratio, $\tan\beta$, of Higgs vacuum expectation values. We point out that when $\tan\beta$ is large, so are certain corrections to the $b$ quark mass prediction, unless a particular hierarchy exists in the parameters of the model. With such a hierarchy, which may result from approximate symmetries, the top mass prediction depends only weakly on the spectrum. Our results may be applied to any supersymmetric SO(10)-like model as long as $\lambda_t\simeq \lambda_b\simeq\lambda_\tau$ at the GUT scale and there are no intermediate mass scales in the desert.
hep-ph/0212316
Dmitri Kharzeev
D. Kharzeev, E. Levin and M. Nardi
QCD Saturation and Deuteron-Nucleus Collisions
16 pages, 5 figures; added Erratum with a discussion of centrality selection procedure and comparison to the published experimental results
Nucl.Phys.A730:448-459,2004; Erratum-ibid.A743:329-331,2004
10.1016/j.nuclphysa.2004.06.022
BNL-NT-02/30
hep-ph nucl-ex nucl-th
null
We make quantitative predictions for the rapidity and centrality dependencies of hadron multiplicities in dA collisions at RHIC basing on the ideas of parton saturation in the Color Glass Condensate.
[ { "created": "Fri, 20 Dec 2002 16:26:41 GMT", "version": "v1" }, { "created": "Thu, 16 Jan 2003 15:32:29 GMT", "version": "v2" }, { "created": "Tue, 12 Aug 2003 20:06:37 GMT", "version": "v3" }, { "created": "Mon, 8 Mar 2004 20:32:00 GMT", "version": "v4" } ]
2010-11-30
[ [ "Kharzeev", "D.", "" ], [ "Levin", "E.", "" ], [ "Nardi", "M.", "" ] ]
We make quantitative predictions for the rapidity and centrality dependencies of hadron multiplicities in dA collisions at RHIC basing on the ideas of parton saturation in the Color Glass Condensate.
2311.05683
Mario Fern\'andez Navarro
Mario Fern\'andez Navarro, Stephen F. King and Avelino Vicente
Tri-unification: a separate $SU(5)$ for each fermion family
19 pages + Appendix, 7 figures. v4: minor changes to scalar reps, conclusions unchanged
JHEP 05 (2024) 130
10.1007/JHEP05(2024)130
IFIC/23-48
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In this paper we discuss $SU(5)^{3}$ with cyclic symmetry as a possible grand unified theory (GUT). The basic idea of such a tri-unification is that there is a separate $SU(5)$ for each fermion family, with the light Higgs doublet(s) arising from the third family $SU(5)$, providing a basis for charged fermion mass hierarchies. $SU(5)^{3}$ tri-unification reconciles the idea of gauge non-universality with the idea of gauge coupling unification, opening the possibility to build consistent non-universal descriptions of Nature that are valid all the way up to the scale of grand unification. As a concrete example, we propose a grand unified embedding of the tri-hypercharge model $U(1)_Y^3$ based on an $SU(5)^{3}$ framework with cyclic symmetry. We discuss a minimal tri-hypercharge example which can account for all the quark and lepton (including neutrino) masses and mixing parameters. We show that it is possible to unify the many gauge couplings into a single gauge coupling associated with the cyclic $SU(5)^{3}$ gauge group, by assuming minimal multiplet splitting, together with a set of relatively light colour octet scalars. We also study proton decay in this example, and present the predictions for the proton lifetime in the dominant $e^+\pi^0$ channel.
[ { "created": "Thu, 9 Nov 2023 19:00:02 GMT", "version": "v1" }, { "created": "Mon, 20 Nov 2023 11:14:02 GMT", "version": "v2" }, { "created": "Mon, 13 May 2024 13:25:04 GMT", "version": "v3" }, { "created": "Wed, 26 Jun 2024 15:23:02 GMT", "version": "v4" } ]
2024-06-27
[ [ "Navarro", "Mario Fernández", "" ], [ "King", "Stephen F.", "" ], [ "Vicente", "Avelino", "" ] ]
In this paper we discuss $SU(5)^{3}$ with cyclic symmetry as a possible grand unified theory (GUT). The basic idea of such a tri-unification is that there is a separate $SU(5)$ for each fermion family, with the light Higgs doublet(s) arising from the third family $SU(5)$, providing a basis for charged fermion mass hierarchies. $SU(5)^{3}$ tri-unification reconciles the idea of gauge non-universality with the idea of gauge coupling unification, opening the possibility to build consistent non-universal descriptions of Nature that are valid all the way up to the scale of grand unification. As a concrete example, we propose a grand unified embedding of the tri-hypercharge model $U(1)_Y^3$ based on an $SU(5)^{3}$ framework with cyclic symmetry. We discuss a minimal tri-hypercharge example which can account for all the quark and lepton (including neutrino) masses and mixing parameters. We show that it is possible to unify the many gauge couplings into a single gauge coupling associated with the cyclic $SU(5)^{3}$ gauge group, by assuming minimal multiplet splitting, together with a set of relatively light colour octet scalars. We also study proton decay in this example, and present the predictions for the proton lifetime in the dominant $e^+\pi^0$ channel.
1312.3097
Kyohei Mukaida
Keisuke Harigaya and Kyohei Mukaida
Thermalization after/during Reheating
20 pages, 4 figures; v2: discussion on abelian gauge theory is modified; v3: published version
JHEP 1405 (2014) 006
10.1007/JHEP05(2014)006
IPMU 13-0233, UT-13-43
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If reheating of the Universe takes place via Planck-suppressed decay, it seems that the thermalization of produced particles might be delayed, since they have large energy/small number densities and number violating large angle scatterings which decrease the momentum of particles by large amount are inefficient correspondingly. In this paper, we study the thermalization of such "under occupied" decay products in detail, following recent developments in understanding the thermalization of non-abelian plasma. Contrary to the above naive expectation, it is shown that in most cases thermalization after/during reheating occurs instantaneously by properly taking account of scatterings with small angles and of particles with small momenta. In particular, the condition for instantaneous thermalization before the completion of reheating is found to be $\alpha^{8/5} \gg (m_\phi / M_{\rm pl}) (M_{\rm pl}^2 \Gamma_\phi / m_\phi^3)^{1/5}$, which is much milder than that obtained in previous works with small angle scatterings taken into account.
[ { "created": "Wed, 11 Dec 2013 09:50:52 GMT", "version": "v1" }, { "created": "Mon, 16 Dec 2013 13:46:22 GMT", "version": "v2" }, { "created": "Tue, 20 May 2014 19:46:44 GMT", "version": "v3" } ]
2014-05-21
[ [ "Harigaya", "Keisuke", "" ], [ "Mukaida", "Kyohei", "" ] ]
If reheating of the Universe takes place via Planck-suppressed decay, it seems that the thermalization of produced particles might be delayed, since they have large energy/small number densities and number violating large angle scatterings which decrease the momentum of particles by large amount are inefficient correspondingly. In this paper, we study the thermalization of such "under occupied" decay products in detail, following recent developments in understanding the thermalization of non-abelian plasma. Contrary to the above naive expectation, it is shown that in most cases thermalization after/during reheating occurs instantaneously by properly taking account of scatterings with small angles and of particles with small momenta. In particular, the condition for instantaneous thermalization before the completion of reheating is found to be $\alpha^{8/5} \gg (m_\phi / M_{\rm pl}) (M_{\rm pl}^2 \Gamma_\phi / m_\phi^3)^{1/5}$, which is much milder than that obtained in previous works with small angle scatterings taken into account.
1103.0914
Tobias Kasprzik
Ansgar Denner, Stefan Dittmaier, Tobias Kasprzik, Alexander M\"uck
Electroweak corrections to dilepton + jet production at hadron colliders
32 pages, 13 figures. v2, further phenomenological results included, version published in JHEP
JHEP06 (2011) 069
10.1007/JHEP06(2011)069
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first calculation of the next-to-leading-order electroweak corrections to Z-boson + jet hadroproduction including leptonic Z-boson decays is presented, i.e. to the production of a charged lepton--anti-lepton final state in association with one hard jet at the LHC and the Tevatron. The Z-boson resonance is treated consistently using the complex-mass scheme, and all off-shell effects as well as the contributions of the intermediate photon are taken into account. The corresponding next-to-leading-order QCD corrections have also been recalculated. The full calculation is implemented in a flexible Monte Carlo code. Numerical results for cross sections and distributions of this Standard Model benchmark process are presented for the Tevatron and the LHC.
[ { "created": "Fri, 4 Mar 2011 14:47:33 GMT", "version": "v1" }, { "created": "Wed, 13 Jul 2011 12:53:09 GMT", "version": "v2" } ]
2015-05-27
[ [ "Denner", "Ansgar", "" ], [ "Dittmaier", "Stefan", "" ], [ "Kasprzik", "Tobias", "" ], [ "Mück", "Alexander", "" ] ]
The first calculation of the next-to-leading-order electroweak corrections to Z-boson + jet hadroproduction including leptonic Z-boson decays is presented, i.e. to the production of a charged lepton--anti-lepton final state in association with one hard jet at the LHC and the Tevatron. The Z-boson resonance is treated consistently using the complex-mass scheme, and all off-shell effects as well as the contributions of the intermediate photon are taken into account. The corresponding next-to-leading-order QCD corrections have also been recalculated. The full calculation is implemented in a flexible Monte Carlo code. Numerical results for cross sections and distributions of this Standard Model benchmark process are presented for the Tevatron and the LHC.
hep-ph/9608213
Matteo Cacciari
M. Cacciari (DESY), M. Greco (Roma III), S. Rolli (Pavia and LBNL), A. Tanzini (Roma II)
Charmed Mesons Fragmentation Functions
Small changes in text and last figure (inclusion of Sudakov form factors). No qualitative changes in results
Phys.Rev.D55:2736-2740,1997
10.1103/PhysRevD.55.2736
DESY 96-146, LNF-96/037(P), LBNL-39175
hep-ph
null
Fragmentation functions for heavy-light mesons, like the charmed D, D^* mesons, are proposed. They rest on next-to-leading QCD Perturbative Fragmentation Functions for heavy quarks, with the addition of a non-perturbative term describing phenomenologically the quark --> meson transition. The cross section for production of large p_T D, D^* mesons at the Tevatron is evaluated in this framework.
[ { "created": "Fri, 2 Aug 1996 10:02:30 GMT", "version": "v1" }, { "created": "Wed, 13 Nov 1996 18:05:51 GMT", "version": "v2" } ]
2016-09-06
[ [ "Cacciari", "M.", "", "DESY" ], [ "Greco", "M.", "", "Roma III" ], [ "Rolli", "S.", "", "Pavia and LBNL" ], [ "Tanzini", "A.", "", "Roma II" ] ]
Fragmentation functions for heavy-light mesons, like the charmed D, D^* mesons, are proposed. They rest on next-to-leading QCD Perturbative Fragmentation Functions for heavy quarks, with the addition of a non-perturbative term describing phenomenologically the quark --> meson transition. The cross section for production of large p_T D, D^* mesons at the Tevatron is evaluated in this framework.
1001.3884
Sebastian Cassel
S. Cassel, D. M. Ghilencea, G. G. Ross
Testing SUSY at the LHC: Electroweak and Dark matter fine tuning at two-loop order
36 pages, 24 figures
Nucl.Phys.B835:110-134,2010
10.1016/j.nuclphysb.2010.03.031
OUTP-0930P, CERN-PH-TH-259
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the Constrained Minimal Supersymmetric Standard Model (CMSSM) we evaluate the electroweak fine tuning measure that provides a quantitative test of supersymmetry as a solution to the hierarchy problem. Taking account of current experimental constraints we compute the fine tuning at two-loop order and determine the limits on the CMSSM parameter space and the measurements at the LHC most relevant in covering it. Without imposing the LEPII bound on the Higgs mass, it is shown that the fine tuning computed at two-loop has a minimum $\Delta=8.8$ corresponding to a Higgs mass $m_h=114\pm 2$ GeV. Adding the constraint that the SUSY dark matter relic density should be within present bounds we find $\Delta=15$ corresponding to $m_h=114.7\pm 2$ GeV and this rises to $\Delta=17.8$ ($m_h=115.9\pm 2$ GeV) for SUSY dark matter abundance within 3$\sigma$ of the WMAP constraint. We extend the analysis to include the contribution of dark matter fine tuning. In this case the overall fine tuning and Higgs mass are only marginally larger for the case SUSY dark matter is subdominant and rises to $\Delta=28.7$ ($m_h=116.98\pm 2$ GeV) for the case of SUSY dark matter saturates the WMAP bound. For a Higgs mass above these values, fine tuning rises exponentially fast. The CMSSM spectrum that corresponds to minimal fine tuning is computed and provides a benchmark for future searches. It is characterised by heavy squarks and sleptons and light neutralinos, charginos and gluinos.
[ { "created": "Fri, 22 Jan 2010 14:14:54 GMT", "version": "v1" } ]
2014-11-20
[ [ "Cassel", "S.", "" ], [ "Ghilencea", "D. M.", "" ], [ "Ross", "G. G.", "" ] ]
In the framework of the Constrained Minimal Supersymmetric Standard Model (CMSSM) we evaluate the electroweak fine tuning measure that provides a quantitative test of supersymmetry as a solution to the hierarchy problem. Taking account of current experimental constraints we compute the fine tuning at two-loop order and determine the limits on the CMSSM parameter space and the measurements at the LHC most relevant in covering it. Without imposing the LEPII bound on the Higgs mass, it is shown that the fine tuning computed at two-loop has a minimum $\Delta=8.8$ corresponding to a Higgs mass $m_h=114\pm 2$ GeV. Adding the constraint that the SUSY dark matter relic density should be within present bounds we find $\Delta=15$ corresponding to $m_h=114.7\pm 2$ GeV and this rises to $\Delta=17.8$ ($m_h=115.9\pm 2$ GeV) for SUSY dark matter abundance within 3$\sigma$ of the WMAP constraint. We extend the analysis to include the contribution of dark matter fine tuning. In this case the overall fine tuning and Higgs mass are only marginally larger for the case SUSY dark matter is subdominant and rises to $\Delta=28.7$ ($m_h=116.98\pm 2$ GeV) for the case of SUSY dark matter saturates the WMAP bound. For a Higgs mass above these values, fine tuning rises exponentially fast. The CMSSM spectrum that corresponds to minimal fine tuning is computed and provides a benchmark for future searches. It is characterised by heavy squarks and sleptons and light neutralinos, charginos and gluinos.
hep-ph/0108261
Danny Marfatia
V. Barger, T. Han, S. Hesselbach and D. Marfatia
Testing radiative neutrino mass generation via R-parity violation at the Tevatron
Version to appear in PLB
Phys.Lett.B538:346-352,2002
10.1016/S0370-2693(02)02024-5
MADPH-01-1241
hep-ph
null
An R-parity violating SUSY model with lepton-number violating couplings $\lambda'_{i33}$, i=2,3 can generate a neutrino mass spectrum that explains the recent results from neutrino oscillation experiments. These R-parity violating couplings lead to a clean signal with at least one isolated lepton and at least three tagged $b$ jets that is accessible in chargino and neutralino production at the Tevatron collider. This signature can be probed at $3 \sigma$ up to $m_{1/2} = 230$ GeV (320 GeV) with an integrated luminosity of $2 fb^{-1}$ ($30 fb^{-1}$).
[ { "created": "Thu, 30 Aug 2001 22:54:11 GMT", "version": "v1" }, { "created": "Fri, 31 Aug 2001 21:34:05 GMT", "version": "v2" }, { "created": "Fri, 24 May 2002 23:05:53 GMT", "version": "v3" } ]
2009-09-15
[ [ "Barger", "V.", "" ], [ "Han", "T.", "" ], [ "Hesselbach", "S.", "" ], [ "Marfatia", "D.", "" ] ]
An R-parity violating SUSY model with lepton-number violating couplings $\lambda'_{i33}$, i=2,3 can generate a neutrino mass spectrum that explains the recent results from neutrino oscillation experiments. These R-parity violating couplings lead to a clean signal with at least one isolated lepton and at least three tagged $b$ jets that is accessible in chargino and neutralino production at the Tevatron collider. This signature can be probed at $3 \sigma$ up to $m_{1/2} = 230$ GeV (320 GeV) with an integrated luminosity of $2 fb^{-1}$ ($30 fb^{-1}$).
hep-ph/9312347
D. P. Roy
Debajyoti Choudhury and D.P. Roy
Signatures of an invisibly decaying Higgs particles at LHC
(e-mail: dproy@theory.tifr.res.in) LaTex; No. of pages 12, no. of figures 3 (available on request)
Phys.Lett.B322:368-373,1994
10.1016/0370-2693(94)91167-3
null
hep-ph
null
The Higgs particle can decay dominantly into an invisible channel in the Majoron models. We have explored the prospect of detecting such a Higgs particle at LHC via its associated production with a gluon, Z or W boson. While the signal/background ratio is too small for the first process, the latter two provide viable signatures for detecting such a Higgs particle.
[ { "created": "Tue, 28 Dec 1993 15:11:11 GMT", "version": "v1" } ]
2009-09-25
[ [ "Choudhury", "Debajyoti", "" ], [ "Roy", "D. P.", "" ] ]
The Higgs particle can decay dominantly into an invisible channel in the Majoron models. We have explored the prospect of detecting such a Higgs particle at LHC via its associated production with a gluon, Z or W boson. While the signal/background ratio is too small for the first process, the latter two provide viable signatures for detecting such a Higgs particle.
hep-ph/0204013
Ernest Ma
Ernest Ma (UC Riverside)
Neutrino Mass from Triplet and Doublet Scalars at the TeV Scale
6 pages, no figure
Phys.Rev. D66 (2002) 037301
10.1103/PhysRevD.66.037301
UCRHEP-T334 (April 2002)
hep-ph
null
If the minimal standard model of particle interactions is extended to include a scalar triplet with lepton number $L=-2$ and a scalar doublet with $L=-1$, neutrino masses $m_\nu \sim \mu_{12}^4 v^2/M^5 \sim 10^{-2}$ eV is possible, where $v \sim 10^2$ GeV is the electroweak symmetry breaking scale, $M \sim 1$ TeV is the typical mass of the new scalars, and $\mu_{12} \sim 1$ GeV is a soft lepton-number-violating parameter.
[ { "created": "Mon, 1 Apr 2002 21:09:27 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
If the minimal standard model of particle interactions is extended to include a scalar triplet with lepton number $L=-2$ and a scalar doublet with $L=-1$, neutrino masses $m_\nu \sim \mu_{12}^4 v^2/M^5 \sim 10^{-2}$ eV is possible, where $v \sim 10^2$ GeV is the electroweak symmetry breaking scale, $M \sim 1$ TeV is the typical mass of the new scalars, and $\mu_{12} \sim 1$ GeV is a soft lepton-number-violating parameter.
hep-ph/9502380
null
Yi-Yen Wu (Lawrence Berkeley Laboratory)
The Minimal Supersymmetric Model of Higgs-Higgs Condensation
The discussion of the following two topics are included, (1). How large can the lightest-Higgs mass be in the supersymmetric standard models? (2). The triviality bound of the Higgs mass, with the conclusion that the SUSY model of Higgs-Higgs condensation will be the most promising candidate if the lightest-Higgs mass of the MSSM is excluded by the future experiments
Phys.Rev. D52 (1995) 6562-6576
10.1103/PhysRevD.52.6562
LBL-36516, UCB-PTH-94/34
hep-ph
null
This paper is motivated by three issues associated with the supersymmetric extension of the standard model: the $\mu$ problem, the possibility of raising the upper bound on the lightest-Higgs mass, and the triviality problem associated with the Higgs sector. A new scheme based on the Higgs-Higgs condensation is proposed, and it is shown that these three issues are well solved by this scheme. As the first realization of this new scheme, the Minimal Supersymmetric Model of Higgs-Higgs Condensation (MSMHHC) is constructed and studied in detail. The MSMHHC is identical with the MSSM (Minimal Supersymmetric Standard Model) in the fundamental particle content, and their lagrangians differ only in the Higgs sector. The Higgs sector of the MSMHHC is based on the softly-broken supersymmetric Nambu$-$Jona-Lasinio model with the four-field interaction of the Higgs doublets. At low energy, these two Higgs doublets condense into two neutral Higgs gauge singlets, and the low-energy effective lagrangian of the MSMHHC has the form of the non-minimal supersymmetric standard model which contains two more Higgs singlets than the MSSM. Another unique feature of the MSMHHC is that heavy top quark always implies strongly-interacting low-energy Higgs sector, i.e., a large mass for the lightest Higgs boson. A systematic study of the parameter space is also made in order to reveal the qualitative features of the MSMHHC. Finally, we comment on the question "How large can the lightest-Higgs mass be?" with the conclusion that the supersymmetric model of Higgs-Higgs condensation will be the most promising candidate if the lightest-Higgs mass of the MSSM is excluded by the future experiments.
[ { "created": "Fri, 24 Feb 1995 04:30:45 GMT", "version": "v1" }, { "created": "Wed, 15 Mar 1995 04:14:42 GMT", "version": "v2" }, { "created": "Tue, 4 Jul 1995 04:53:12 GMT", "version": "v3" } ]
2009-10-28
[ [ "Wu", "Yi-Yen", "", "Lawrence Berkeley Laboratory" ] ]
This paper is motivated by three issues associated with the supersymmetric extension of the standard model: the $\mu$ problem, the possibility of raising the upper bound on the lightest-Higgs mass, and the triviality problem associated with the Higgs sector. A new scheme based on the Higgs-Higgs condensation is proposed, and it is shown that these three issues are well solved by this scheme. As the first realization of this new scheme, the Minimal Supersymmetric Model of Higgs-Higgs Condensation (MSMHHC) is constructed and studied in detail. The MSMHHC is identical with the MSSM (Minimal Supersymmetric Standard Model) in the fundamental particle content, and their lagrangians differ only in the Higgs sector. The Higgs sector of the MSMHHC is based on the softly-broken supersymmetric Nambu$-$Jona-Lasinio model with the four-field interaction of the Higgs doublets. At low energy, these two Higgs doublets condense into two neutral Higgs gauge singlets, and the low-energy effective lagrangian of the MSMHHC has the form of the non-minimal supersymmetric standard model which contains two more Higgs singlets than the MSSM. Another unique feature of the MSMHHC is that heavy top quark always implies strongly-interacting low-energy Higgs sector, i.e., a large mass for the lightest Higgs boson. A systematic study of the parameter space is also made in order to reveal the qualitative features of the MSMHHC. Finally, we comment on the question "How large can the lightest-Higgs mass be?" with the conclusion that the supersymmetric model of Higgs-Higgs condensation will be the most promising candidate if the lightest-Higgs mass of the MSSM is excluded by the future experiments.
1011.1756
Jacques Soffer
C. Bourrely, J. Soffer and T.T. Wu
Determination of the forward slope in $p~p$ and $\bar p~p$ elastic scattering up to LHC energy
12 pages, 6 figures, to appear in EPJC
Eur.Phys.J.C71:1601,2011
10.1140/epjc/s10052-011-1601-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the analysis of experimental data on $p p$ (or $\bar p p$) elastic differential cross section it is customary to define an average forward slope $b$ in the form $\exp{(-b|t|)}$, where $t$ is the momentum transfer. Taking as working example the results of experiments at Tevatron and SPS, we will show with the help of the impact picture approach, that this simplifying assumption hides interesting information on the complex non-flip scattering amplitude, and that the slope $b$ is not a constant. We investigate the variation of this slope parameter, including a model-independent way to extract this information from an accurate measurement of the elastic differential cross section. An extension of our results to the LHC energy domain is presented in view of future experiments.
[ { "created": "Mon, 8 Nov 2010 10:27:40 GMT", "version": "v1" }, { "created": "Wed, 9 Mar 2011 08:46:34 GMT", "version": "v2" } ]
2011-04-04
[ [ "Bourrely", "C.", "" ], [ "Soffer", "J.", "" ], [ "Wu", "T. T.", "" ] ]
In the analysis of experimental data on $p p$ (or $\bar p p$) elastic differential cross section it is customary to define an average forward slope $b$ in the form $\exp{(-b|t|)}$, where $t$ is the momentum transfer. Taking as working example the results of experiments at Tevatron and SPS, we will show with the help of the impact picture approach, that this simplifying assumption hides interesting information on the complex non-flip scattering amplitude, and that the slope $b$ is not a constant. We investigate the variation of this slope parameter, including a model-independent way to extract this information from an accurate measurement of the elastic differential cross section. An extension of our results to the LHC energy domain is presented in view of future experiments.
2206.08876
Jose Osvaldo Gonzalez Hernandez
M. Boglione, J.O. Gonzalez-Hernandez, A. Simonelli
Transverse Momentum Dependent Fragmentation Functions from recent BELLE data
19 pages, 14 figures, 6 tables
null
10.1103/PhysRevD.106.074024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new formalism for the factorization of the cross section for single hadron production in $e^+e^-$ annihilations, differential in $z_h$, $P_T$ and thrust, is applied to the phenomenological analysis of data recently measured by the BELLE Collaboration. Within this scheme the $e^+e^- \to hX$ cross section can be recast in the convolution of a perturbatively calculable coefficient and a universal transverse momentum dependent fragmentation function. While performing a next-to-leading order calculation of the perturbative part of the process to next-to-leading logarithmic accuracy, we examine and thoroughly discuss the suitability of a number of possible ansatz to model the non-perturbative part of this universal transverse momentum dependent fragmentation function, showing the extent to which present experimental data can actually constrain its shape and functional form in terms of $z_h$, $P_T$ and thrust.
[ { "created": "Fri, 17 Jun 2022 16:25:16 GMT", "version": "v1" } ]
2022-11-09
[ [ "Boglione", "M.", "" ], [ "Gonzalez-Hernandez", "J. O.", "" ], [ "Simonelli", "A.", "" ] ]
A new formalism for the factorization of the cross section for single hadron production in $e^+e^-$ annihilations, differential in $z_h$, $P_T$ and thrust, is applied to the phenomenological analysis of data recently measured by the BELLE Collaboration. Within this scheme the $e^+e^- \to hX$ cross section can be recast in the convolution of a perturbatively calculable coefficient and a universal transverse momentum dependent fragmentation function. While performing a next-to-leading order calculation of the perturbative part of the process to next-to-leading logarithmic accuracy, we examine and thoroughly discuss the suitability of a number of possible ansatz to model the non-perturbative part of this universal transverse momentum dependent fragmentation function, showing the extent to which present experimental data can actually constrain its shape and functional form in terms of $z_h$, $P_T$ and thrust.
1906.10831
Suyong Choi
Suyong Choi and Hayoung Oh
Improved Extrapolation Methods of Data-driven Background Estimation in High-Energy Physics
11 pages, 5 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Data-driven methods of background estimations are often used to obtain more reliable descriptions of backgrounds. In hadron collider experiments, data-driven techniques are used to estimate backgrounds due to multi-jet events, which are difficult to model accurately. In this article, we propose an improvement on one of the most widely used data-driven methods in the hadron collision environment, the "ABCD" method of extrapolation. We describe the mathematical background behind the data-driven methods and extend the idea to propose improved general methods.
[ { "created": "Wed, 26 Jun 2019 03:51:49 GMT", "version": "v1" }, { "created": "Thu, 27 Feb 2020 03:59:34 GMT", "version": "v2" }, { "created": "Fri, 6 Mar 2020 03:49:19 GMT", "version": "v3" }, { "created": "Sat, 3 Jul 2021 22:38:37 GMT", "version": "v4" } ]
2021-07-06
[ [ "Choi", "Suyong", "" ], [ "Oh", "Hayoung", "" ] ]
Data-driven methods of background estimations are often used to obtain more reliable descriptions of backgrounds. In hadron collider experiments, data-driven techniques are used to estimate backgrounds due to multi-jet events, which are difficult to model accurately. In this article, we propose an improvement on one of the most widely used data-driven methods in the hadron collision environment, the "ABCD" method of extrapolation. We describe the mathematical background behind the data-driven methods and extend the idea to propose improved general methods.
hep-ph/9901395
Mustafa Savci
T. M. Aliev, M. Savci (Middle East Technical University-Ankara-Turkey)
Semileptonic B -> a_1 l nu decay in QCD
12 pages, 2 figures, LaTeX formatted
Phys.Lett. B456 (1999) 256-263
10.1016/S0370-2693(99)00466-9
METU-PHYS-HEP-99-3
hep-ph
null
The form factors and the branching ratio of the "B -> a_1 l nu" decay are calculated in framework of QCD sum rules. A comparison of our results on form factors and branching ratio with the results from constituent quark model is presented.
[ { "created": "Sun, 24 Jan 1999 17:50:10 GMT", "version": "v1" } ]
2009-10-31
[ [ "Aliev", "T. M.", "", "Middle East Technical University-Ankara-Turkey" ], [ "Savci", "M.", "", "Middle East Technical University-Ankara-Turkey" ] ]
The form factors and the branching ratio of the "B -> a_1 l nu" decay are calculated in framework of QCD sum rules. A comparison of our results on form factors and branching ratio with the results from constituent quark model is presented.
hep-ph/9705419
Seungho Choe
Seungho Choe (Yonsei University)
Multiquark states and QCD sum rules
Latex, 6 pages, 2 ps figures. Talk given at YITP international Workshop on Recent Developments in QCD and Hadron Physics, Kyoto, Japan, Dec. 16-18, 1996
Soryushiron Kenkyu 95:D87,1997
null
null
hep-ph nucl-th
null
There have been arguments about hadronic molecules, which are weakly-bound states of two or more hadrons. We investigate the possibility of some candidates (f0 (980), a0 (980), f0 (1500), f0 (1710), etc.) using QCD sum rule approach and compare our results with multiquark states in the MIT bag model. We find that f0 (1500), f0 (1710) can be good candidates for vector-vector molecule-type multiquark states.
[ { "created": "Mon, 26 May 1997 04:28:13 GMT", "version": "v1" } ]
2011-04-15
[ [ "Choe", "Seungho", "", "Yonsei University" ] ]
There have been arguments about hadronic molecules, which are weakly-bound states of two or more hadrons. We investigate the possibility of some candidates (f0 (980), a0 (980), f0 (1500), f0 (1710), etc.) using QCD sum rule approach and compare our results with multiquark states in the MIT bag model. We find that f0 (1500), f0 (1710) can be good candidates for vector-vector molecule-type multiquark states.
1706.08309
Nicolas Greiner
Daniel Faeh, Nicolas Greiner
Diphoton production in association with two bottom jets
19 pages, 10 figures
null
10.1140/epjc/s10052-017-5296-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production of a photon pair in association with two bottom jets at the LHC. This process constitutes an important background to double Higgs production with the subsequent decay of the two Higgs bosons into a pair of photons and b-quarks respectively. We calculate this process at next-to-leading order accuracy in QCD and find that QCD corrections lead to a substantial increase of the production cross section due to new channels opening up at next-to-leading order and their inclusion is therefore inevitable for a reliable prediction. Furthermore, the approximation of massless b-quarks is scrutinized by calculating the process with both massless and massive b-quarks. We find that the massive bottom quark leads to a substantial reduction of the cross section where the biggest effect is however due to the use of a four flavor PDF set and the corresponding smaller values for the strong coupling constant.
[ { "created": "Mon, 26 Jun 2017 10:19:57 GMT", "version": "v1" } ]
2017-12-06
[ [ "Faeh", "Daniel", "" ], [ "Greiner", "Nicolas", "" ] ]
We study the production of a photon pair in association with two bottom jets at the LHC. This process constitutes an important background to double Higgs production with the subsequent decay of the two Higgs bosons into a pair of photons and b-quarks respectively. We calculate this process at next-to-leading order accuracy in QCD and find that QCD corrections lead to a substantial increase of the production cross section due to new channels opening up at next-to-leading order and their inclusion is therefore inevitable for a reliable prediction. Furthermore, the approximation of massless b-quarks is scrutinized by calculating the process with both massless and massive b-quarks. We find that the massive bottom quark leads to a substantial reduction of the cross section where the biggest effect is however due to the use of a four flavor PDF set and the corresponding smaller values for the strong coupling constant.
hep-ph/9703232
Ewan Davidson Stewart
Ewan D. Stewart
Flattening the Inflaton's Potential with Quantum Corrections II
14 pages, latex, 3 epsf figures
Phys. Rev. D 56, 2019 (1997)
10.1103/PhysRevD.56.2019
RESCEU-9/97
hep-ph astro-ph gr-qc hep-th
null
In a previous paper I showed that a classical scalar potential with $V''/V \sim 1$ can be sufficiently flattened by quantum corrections to give rise to slow-roll inflation. In this paper I give a hybrid inflation implementation of that idea which can naturally produce a spectral index in the observationally viable range even for $V^{1/4} \sim 10^{10}$ to $10^{11}$ GeV. Although any observationally viable spectral index can be obtained, the model does predict a distinctive spectral shape.
[ { "created": "Tue, 4 Mar 1997 17:07:31 GMT", "version": "v1" } ]
2016-08-24
[ [ "Stewart", "Ewan D.", "" ] ]
In a previous paper I showed that a classical scalar potential with $V''/V \sim 1$ can be sufficiently flattened by quantum corrections to give rise to slow-roll inflation. In this paper I give a hybrid inflation implementation of that idea which can naturally produce a spectral index in the observationally viable range even for $V^{1/4} \sim 10^{10}$ to $10^{11}$ GeV. Although any observationally viable spectral index can be obtained, the model does predict a distinctive spectral shape.
2011.13291
Zhi-Gang Wang
Zun-Yan Di, Zhi-Gang Wang, Guo-Liang Yu
Analysis of the possible $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ molecules with QCD sum rules
17 pages, 10 figures. arXiv admin note: text overlap with arXiv:1806.08703, arXiv:1901.05196, arXiv:1802.05354
Commun.Theor.Phys.71(2019)685
10.1088/0253-6102/71/6/685
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this article, we assume that there exist the pseudoscalar $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ molecular states $Z_{1,2}$ and construct the color singlet-singlet molecule-type interpolating currents to study their masses with the QCD sum rules. In calculations, we consider the contributions of the vacuum condensates up to dimension-10 and use the formula $\mu=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}}$ to determine the energy scales of the QCD spectral densities. The numerical results, $M_{Z_1}=4.61_{-0.08}^{+0.11}\,\text{GeV}$ and $M_{Z_2}=4.60_{-0.06}^{+0.07}\,\text{GeV}$, which lie above the $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ thresholds respectively, indicate that the $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ are difficult to form bound state molecular states, the $Z_{1,2}$ are probably resonance states.
[ { "created": "Thu, 26 Nov 2020 13:45:20 GMT", "version": "v1" } ]
2020-11-30
[ [ "Di", "Zun-Yan", "" ], [ "Wang", "Zhi-Gang", "" ], [ "Yu", "Guo-Liang", "" ] ]
In this article, we assume that there exist the pseudoscalar $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ molecular states $Z_{1,2}$ and construct the color singlet-singlet molecule-type interpolating currents to study their masses with the QCD sum rules. In calculations, we consider the contributions of the vacuum condensates up to dimension-10 and use the formula $\mu=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}}$ to determine the energy scales of the QCD spectral densities. The numerical results, $M_{Z_1}=4.61_{-0.08}^{+0.11}\,\text{GeV}$ and $M_{Z_2}=4.60_{-0.06}^{+0.07}\,\text{GeV}$, which lie above the $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ thresholds respectively, indicate that the $D\bar{D}_{s0}^*(2317)$ and $D^*\bar{D}_{s1}^*(2460)$ are difficult to form bound state molecular states, the $Z_{1,2}$ are probably resonance states.
hep-ph/9903438
Claude Bourrely
C. Bourrely, J. Soffer and Tai Tsun Wu
Impact-picture predictions for the $\gamma\gamma$ total cross section at LEP
5 pages, Latex, 1 figure. Revised version
Mod.Phys.Lett.A15:9-13,2000
10.1016/S0217-7323(00)00003-7
CPT-99/P.3793, CERN-TH/99-76
hep-ph
null
We show that the rising total cross section $\sigma(\gamma\gamma \to hadrons)$ recently observed by the L3 and OPAL Collaborations at LEP are fully consistent with the impact-picture for high-energy scattering. The impact picture is then used to predict this total cross section at higher energies. These experimental results confirm once more the success of the theoretical approach, which predicted for the first time, nearly thirty years ago, the universal increase of total cross sections at high energies.
[ { "created": "Mon, 22 Mar 1999 11:49:32 GMT", "version": "v1" }, { "created": "Wed, 16 Jun 1999 12:19:13 GMT", "version": "v2" } ]
2009-12-15
[ [ "Bourrely", "C.", "" ], [ "Soffer", "J.", "" ], [ "Wu", "Tai Tsun", "" ] ]
We show that the rising total cross section $\sigma(\gamma\gamma \to hadrons)$ recently observed by the L3 and OPAL Collaborations at LEP are fully consistent with the impact-picture for high-energy scattering. The impact picture is then used to predict this total cross section at higher energies. These experimental results confirm once more the success of the theoretical approach, which predicted for the first time, nearly thirty years ago, the universal increase of total cross sections at high energies.
1404.2924
Felix Yu
Felix Yu
Anatomizing Exotic Production of the Higgs Boson
27 pages
Phys. Rev. D 90, 015009 (2014)
10.1103/PhysRevD.90.015009
FERMILAB-PUB-14-072-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss exotic production modes of the Higgs boson and how their phenomenology can be probed in current Higgs analyses. We highlight the importance of differential distributions in disentangling standard production mechanisms from exotic modes. We present two model benchmarks for exotic Higgs production arising from chargino-neutralino production and study their impact on the current Higgs dataset. As a corollary, we emphasize that current Higgs coupling fits do not fully explore the space of new physics deviations possible in Higgs data.
[ { "created": "Thu, 10 Apr 2014 19:59:25 GMT", "version": "v1" } ]
2014-07-16
[ [ "Yu", "Felix", "" ] ]
We discuss exotic production modes of the Higgs boson and how their phenomenology can be probed in current Higgs analyses. We highlight the importance of differential distributions in disentangling standard production mechanisms from exotic modes. We present two model benchmarks for exotic Higgs production arising from chargino-neutralino production and study their impact on the current Higgs dataset. As a corollary, we emphasize that current Higgs coupling fits do not fully explore the space of new physics deviations possible in Higgs data.
hep-ph/9506279
Gerhard Schuler
Gerhard A. Schuler (CERN and Regensburg)
On the non-perturbative part of the photon structure function
Latex, 7 pages
null
null
CERN-TH/95-153
hep-ph
null
We discuss a dispersion relation in the photon mass and show how (in principle) model-independent constraints on the parton distribution functions of the photon, notably a momentum sumrule, can be obtained. We present two sets of parametrizations, SaS~1 and~2, corresponding to two rather extreme realizations of the non-perturbative part. Inclusive electron scattering off a real photon is found to be insufficient to constrain the non-perturbative components. The additional sensitivity provided by the photon virtuality is outlined. Previous approaches to model the non-perturbative input distributions are commented upon.
[ { "created": "Fri, 9 Jun 1995 13:53:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schuler", "Gerhard A.", "", "CERN and Regensburg" ] ]
We discuss a dispersion relation in the photon mass and show how (in principle) model-independent constraints on the parton distribution functions of the photon, notably a momentum sumrule, can be obtained. We present two sets of parametrizations, SaS~1 and~2, corresponding to two rather extreme realizations of the non-perturbative part. Inclusive electron scattering off a real photon is found to be insufficient to constrain the non-perturbative components. The additional sensitivity provided by the photon virtuality is outlined. Previous approaches to model the non-perturbative input distributions are commented upon.
1701.06935
Wilfried Buchmuller
Wilfried Buchmuller and Julian Schweizer
Flavour mixings in flux compactifications
28 pages, 3 figures, 3 tables
Phys. Rev. D 95, 075024 (2017)
10.1103/PhysRevD.95.075024
DESY 16-238
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A multiplicity of quark-lepton families can naturally arise as zero-modes in flux compactifications. The flavour structure of quark and lepton mass matrices is then determined by the wave function profiles of the zero-modes. We consider a supersymmetric $SO(10)\times U(1)$ model in six dimensions compactified on the orbifold $T^2/{\mathbb Z_2}$ with Abelian magnetic flux. A bulk $\mathbf{16}$-plet charged under the $U(1)$ provides the quark-lepton generations whereas two uncharged $\mathbf{10}$-plets yield two Higgs doublets. Bulk anomaly cancellation requires the presence of additional $\mathbf{16}$- and $\mathbf{10}$-plets. The corresponding zero-modes form vectorlike split multiplets that are needed to obtain a successful flavour phenomenology. We analyze the pattern of flavour mixings for the two heaviest families of the Standard Model and discuss possible generalizations to three and more generations.
[ { "created": "Tue, 24 Jan 2017 15:38:48 GMT", "version": "v1" } ]
2017-04-26
[ [ "Buchmuller", "Wilfried", "" ], [ "Schweizer", "Julian", "" ] ]
A multiplicity of quark-lepton families can naturally arise as zero-modes in flux compactifications. The flavour structure of quark and lepton mass matrices is then determined by the wave function profiles of the zero-modes. We consider a supersymmetric $SO(10)\times U(1)$ model in six dimensions compactified on the orbifold $T^2/{\mathbb Z_2}$ with Abelian magnetic flux. A bulk $\mathbf{16}$-plet charged under the $U(1)$ provides the quark-lepton generations whereas two uncharged $\mathbf{10}$-plets yield two Higgs doublets. Bulk anomaly cancellation requires the presence of additional $\mathbf{16}$- and $\mathbf{10}$-plets. The corresponding zero-modes form vectorlike split multiplets that are needed to obtain a successful flavour phenomenology. We analyze the pattern of flavour mixings for the two heaviest families of the Standard Model and discuss possible generalizations to three and more generations.
1004.3192
Valeriy Nazaruk
V.I.Nazaruk
$n\bar{n}$ conversion in finite nuclei
12 pages, 1 figures
null
10.1142/S0218301311018368
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The new model of $n\bar{n}$ transitions in nuclei based on unitary $S$-matrix is considered. The $|in>$-state of nucleus is described by single-particle shell model. The dynamical process part is calculated by means of field-theoretical approach with finite time interval. The lower limit on the free-space $n\bar{n}$ oscillation time $\tau_{{\rm min}}$ is in the range $10^{16}\; {\rm yr}>\tau_{{\rm min}}>1.2\cdot 10^{9}\; {\rm s}$. \end{abstract}
[ { "created": "Mon, 19 Apr 2010 13:45:36 GMT", "version": "v1" }, { "created": "Tue, 20 Apr 2010 13:46:55 GMT", "version": "v2" }, { "created": "Sun, 6 Feb 2011 16:39:00 GMT", "version": "v3" } ]
2015-05-18
[ [ "Nazaruk", "V. I.", "" ] ]
The new model of $n\bar{n}$ transitions in nuclei based on unitary $S$-matrix is considered. The $|in>$-state of nucleus is described by single-particle shell model. The dynamical process part is calculated by means of field-theoretical approach with finite time interval. The lower limit on the free-space $n\bar{n}$ oscillation time $\tau_{{\rm min}}$ is in the range $10^{16}\; {\rm yr}>\tau_{{\rm min}}>1.2\cdot 10^{9}\; {\rm s}$. \end{abstract}
1510.08452
Anton Rebhan
Frederic Br\"unner, Anton Rebhan
Glueball Decay in the Witten-Sakai-Sugimoto Model and Finite Quark Masses
8 pages, 1 figure. To appear in the proceedings of the 8th International Workshop on Chiral Dynamics, CD2015, Pisa,Italy
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss recent results on the calculation of glueball decay rates in the Witten-Sakai-Sugimoto model, which favor the $f_0(1710)$ meson as a glueball candidate. The flavor asymmetric decay of $f_0(1710)$ is frequently attributed to a putative chiral suppression in glueball decays, which is however questionable in view of the large constituent quark masses induced by chiral symmetry breaking. We find that this can be explained by what we call nonchiral enhancement when finite quark masses are included in the holographic model, with good quantitative agreement with experimental data for $f_0(1710)$. Assuming the latter to indeed be a nearly pure glueball, the model makes essentially parameter-free and thus falsifiable predictions for its decay rates involving vector mesons and an upper limit on the $\eta\eta'$ decay rate.
[ { "created": "Wed, 28 Oct 2015 20:05:16 GMT", "version": "v1" } ]
2015-10-30
[ [ "Brünner", "Frederic", "" ], [ "Rebhan", "Anton", "" ] ]
We discuss recent results on the calculation of glueball decay rates in the Witten-Sakai-Sugimoto model, which favor the $f_0(1710)$ meson as a glueball candidate. The flavor asymmetric decay of $f_0(1710)$ is frequently attributed to a putative chiral suppression in glueball decays, which is however questionable in view of the large constituent quark masses induced by chiral symmetry breaking. We find that this can be explained by what we call nonchiral enhancement when finite quark masses are included in the holographic model, with good quantitative agreement with experimental data for $f_0(1710)$. Assuming the latter to indeed be a nearly pure glueball, the model makes essentially parameter-free and thus falsifiable predictions for its decay rates involving vector mesons and an upper limit on the $\eta\eta'$ decay rate.
hep-ph/0205181
Christine T. H. Davies
Christine Davies
Lattice QCD
Lectures given at 55th Scottish Universities Summer School, St Andrews, August 2001
Heavy Flavour Physics, Scottish Graduate Textbook Series, Institute of Physics 2002, eds C. T. H. Davies and S. M. Playfer
null
null
hep-ph hep-lat
null
A general introduction to lattice QCD suitable for graduate students in experimental and theoretical particle physics. Aimed at those who want to know how lattice calculations are done, and what the pitfalls are, without having to do the calculations themselves.
[ { "created": "Thu, 16 May 2002 14:12:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Davies", "Christine", "" ] ]
A general introduction to lattice QCD suitable for graduate students in experimental and theoretical particle physics. Aimed at those who want to know how lattice calculations are done, and what the pitfalls are, without having to do the calculations themselves.
hep-ph/9503371
PostDoc Its
Xiao-Gang He
TEST OF CP VIOLATION IN NON-LEPTONIC HYPERON DECAYS
3 pages. Talk presented at the Beyond the Standard Model IV, Lake Tahoe, California, December 13 - 18, 1994
null
null
OITS-573
hep-ph
null
In this talk I discuss CP violation in hyperon decays in Left-Right symmetric models. I show that the asymmetry in polarization in $\Lambda \to p\pi^-$ can be as large as $6\times 10^{-4}$ in these models, which is an order of magnitude larger than the Standard Model prediction.
[ { "created": "Sat, 18 Mar 1995 00:05:58 GMT", "version": "v1" } ]
2016-09-01
[ [ "He", "Xiao-Gang", "" ] ]
In this talk I discuss CP violation in hyperon decays in Left-Right symmetric models. I show that the asymmetry in polarization in $\Lambda \to p\pi^-$ can be as large as $6\times 10^{-4}$ in these models, which is an order of magnitude larger than the Standard Model prediction.
hep-ph/9607243
Becirevic
Damir Becirevic
$B \to \rho \ell \nu_\ell$ Form Factors
15 pages, Latex, 4 figures
Phys. Rev. D 54, 6842 (1996)
10.1103/PhysRevD.54.6842
LPTHE 96/52
hep-ph
null
The bounds on the form factors for $B \to \rho \ell \nu_\ell$ decay are studied. Constrained by lattice data and a constrained conformal mapping, the more informations can be obtained for $A_1(q^2)$ form-factor which dominates the decay rate at large $q^2$. Specifically, we confirm a moderately increasing behavior of this form factor.
[ { "created": "Thu, 4 Jul 1996 19:34:36 GMT", "version": "v1" } ]
2016-08-24
[ [ "Becirevic", "Damir", "" ] ]
The bounds on the form factors for $B \to \rho \ell \nu_\ell$ decay are studied. Constrained by lattice data and a constrained conformal mapping, the more informations can be obtained for $A_1(q^2)$ form-factor which dominates the decay rate at large $q^2$. Specifically, we confirm a moderately increasing behavior of this form factor.
2201.01040
Vishal Ngairangbam Singh
Partha Konar and Vishal S. Ngairangbam
Influence of QCD parton shower in deep learning invisible Higgs through vector boson fusion
Added inference results for different signals on each trained network and comparison with matched LO samples for both recoil schemes. Matches accepted version in PRD
null
10.1103/PhysRevD.105.113003
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Vector boson fusion established itself as a highly reliable channel to probe the Higgs boson and an avenue to uncover new physics at the Large Hadron Collider. This channel provides the most stringent bound on Higgs' invisible decay branching ratio, where the current upper limits are significantly higher than the one expected in the Standard Model. It is remarkable that merely low-level calorimeter data from this characteristically simple process can improve this limit substantially by employing sophisticated deep-learning techniques. The construction of such neural networks seems to comprehend the event kinematics and radiation pattern exceptionally well. However, the full potential of this outstanding capability also warrants a precise theoretical projection of QCD parton showering and corresponding radiation pattern. This work demonstrates the relation using different recoil schemes in the parton shower with leading order and higher-order computation.
[ { "created": "Tue, 4 Jan 2022 08:42:20 GMT", "version": "v1" }, { "created": "Thu, 19 May 2022 06:27:57 GMT", "version": "v2" } ]
2022-06-29
[ [ "Konar", "Partha", "" ], [ "Ngairangbam", "Vishal S.", "" ] ]
Vector boson fusion established itself as a highly reliable channel to probe the Higgs boson and an avenue to uncover new physics at the Large Hadron Collider. This channel provides the most stringent bound on Higgs' invisible decay branching ratio, where the current upper limits are significantly higher than the one expected in the Standard Model. It is remarkable that merely low-level calorimeter data from this characteristically simple process can improve this limit substantially by employing sophisticated deep-learning techniques. The construction of such neural networks seems to comprehend the event kinematics and radiation pattern exceptionally well. However, the full potential of this outstanding capability also warrants a precise theoretical projection of QCD parton showering and corresponding radiation pattern. This work demonstrates the relation using different recoil schemes in the parton shower with leading order and higher-order computation.
1408.4785
Ernest Ma
Sean Fraser, Ernest Ma, and Oleg Popov
Scotogenic Inverse Seesaw Model of Neutrino Mass
10 pages, 2 figures, version to appear in PLB
null
10.1016/j.physletb.2014.08.069
UCRHEP-T543 (Aug 2014)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A variation of the original 2006 radiative seesaw model of neutrino mass through dark matter is shown to realize the notion of inverse seesaw naturally. The dark-matter candidate here is the lightest of three real singlet scalars which may also carry flavor.
[ { "created": "Wed, 20 Aug 2014 19:58:37 GMT", "version": "v1" }, { "created": "Sun, 31 Aug 2014 16:30:51 GMT", "version": "v2" } ]
2015-06-22
[ [ "Fraser", "Sean", "" ], [ "Ma", "Ernest", "" ], [ "Popov", "Oleg", "" ] ]
A variation of the original 2006 radiative seesaw model of neutrino mass through dark matter is shown to realize the notion of inverse seesaw naturally. The dark-matter candidate here is the lightest of three real singlet scalars which may also carry flavor.
hep-ph/9702250
Bob Holdom
B. Holdom
Dynamical Nonsupersymmetry Breaking
13 pages, 2 figures, Talk given at the International Workshop on Perspectives of Strong Coupling Gauge Theories (SCGT96), November 1996, Nagoya, Japan
null
null
UTPT-97-02
hep-ph
null
We emphasize the role that anomalous power-law scaling of 4-fermion operators, occurring in the presence of new strong interactions, could have in the generation of quark and lepton masses.
[ { "created": "Tue, 4 Feb 1997 19:04:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Holdom", "B.", "" ] ]
We emphasize the role that anomalous power-law scaling of 4-fermion operators, occurring in the presence of new strong interactions, could have in the generation of quark and lepton masses.
hep-ph/0407221
Tetsuya Onogi
Shoji Hashimoto (KEK) and Tetsuya Onogi (YITP)
Heavy Quarks on the Lattice
38 pages, Latex, ar.sty, 7 figures. A review based on the work until February 2004. To appear in the Annual Review of Nuclear & Particle Science, Vol. 54
Ann.Rev.Nucl.Part.Sci. 54 (2004) 451-486
10.1146/annurev.nucl.53.041002.110550
KEK-CP-155, YITP-04-40
hep-ph
null
Lattice quantum chromodynamics provides first principles calculations for hadrons containing heavy quarks -- charm and bottom quarks. Their mass spectra, decay rates, and some hadronic matrix elements can be calculated on the lattice in a model independent manner. In this review, we introduce the effective theories that treat heavy quarks on the lattice. We summarize results on the heavy quarkonium spectrum, which verify the validity of the effective theory approach. We then discuss applications to $B$ physics, which is the main target of the lattice theory of heavy quarks. We review progress in lattice calculations of the $B$ meson decay constant, the $B$ parameter, semi-leptonic decay form factors, and other important quantities.)
[ { "created": "Tue, 20 Jul 2004 04:49:45 GMT", "version": "v1" } ]
2009-11-10
[ [ "Hashimoto", "Shoji", "", "KEK" ], [ "Onogi", "Tetsuya", "", "YITP" ] ]
Lattice quantum chromodynamics provides first principles calculations for hadrons containing heavy quarks -- charm and bottom quarks. Their mass spectra, decay rates, and some hadronic matrix elements can be calculated on the lattice in a model independent manner. In this review, we introduce the effective theories that treat heavy quarks on the lattice. We summarize results on the heavy quarkonium spectrum, which verify the validity of the effective theory approach. We then discuss applications to $B$ physics, which is the main target of the lattice theory of heavy quarks. We review progress in lattice calculations of the $B$ meson decay constant, the $B$ parameter, semi-leptonic decay form factors, and other important quantities.)
hep-ph/0309165
Ian Jack Dr
I. Jack, D.R.T. Jones and R. Wild
Yukawa Textures and the mu-term
12 pages, uses Harvmac (option "b")
Phys.Lett. B580 (2004) 72-78
10.1016/j.physletb.2003.11.027
LTH 592
hep-ph
null
We show how with an anomaly-free U(1), simple assumptions concerning the origin of Yukawa textures and the Higgs mu-term lead to the prediction of a new physics scale of 10^8GeV and automatic conservation of baryon number.
[ { "created": "Mon, 15 Sep 2003 14:54:48 GMT", "version": "v1" } ]
2010-04-05
[ [ "Jack", "I.", "" ], [ "Jones", "D. R. T.", "" ], [ "Wild", "R.", "" ] ]
We show how with an anomaly-free U(1), simple assumptions concerning the origin of Yukawa textures and the Higgs mu-term lead to the prediction of a new physics scale of 10^8GeV and automatic conservation of baryon number.
1407.1317
Pilar Coloma
Mattias Blennow, Pilar Coloma and Enrique Fernandez-Martinez
Searching for sterile neutrinos at the ESS$\nu$SB
8 pages, 1 figure
null
10.1007/JHEP12(2014)120
FTUAM-14-24, IFT-UAM/CSIC-14-059, NORDITA-2014-81
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ESS$\nu$SB project is a proposed neutrino oscillation experiment based on the European Spallation Source with the search for leptonic CP as its main aim. In this letter we show that a near detector at around 1 km distance from the beamline is not only very desirable for keeping the systematic errors affecting the CP search under control, but would also provide a significant sensitivity probe for sterile neutrino oscillations in the region of the parameter space favored by the long-standing LSND anomaly. We find that the effective mixing angle $\theta_{\mu e}$ can be probed down to $\sin^2(2\theta_{\mu e}) \simeq 2(8)\cdot 10^{-3}$ at $5\sigma$ assuming 15% bin-to-bin (un)correlated systematics.
[ { "created": "Fri, 4 Jul 2014 20:00:09 GMT", "version": "v1" } ]
2015-06-22
[ [ "Blennow", "Mattias", "" ], [ "Coloma", "Pilar", "" ], [ "Fernandez-Martinez", "Enrique", "" ] ]
The ESS$\nu$SB project is a proposed neutrino oscillation experiment based on the European Spallation Source with the search for leptonic CP as its main aim. In this letter we show that a near detector at around 1 km distance from the beamline is not only very desirable for keeping the systematic errors affecting the CP search under control, but would also provide a significant sensitivity probe for sterile neutrino oscillations in the region of the parameter space favored by the long-standing LSND anomaly. We find that the effective mixing angle $\theta_{\mu e}$ can be probed down to $\sin^2(2\theta_{\mu e}) \simeq 2(8)\cdot 10^{-3}$ at $5\sigma$ assuming 15% bin-to-bin (un)correlated systematics.
2305.11079
Jamal Jalilian-Marian
Tolga Altinoluk, Guillaume Beuf and Jamal Jalilian-Marian
Renormalization of the gluon distribution function in the background field formalism
Latex, 20 pages, 2 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We derive the Leading Order DGLAP evolution of gluon distribution function in the target light cone gauge starting from its standard operator definition. The derivation is performed using the background field formalism employed in the Color Glass Condensate effective theory of small $x$ QCD. We adopt Mandelstam-Leibbrandt prescription to regulate in an unambiguous way the spurious singularity appearing in the light-cone gauge Feynman propagator. UV divergences are regulated via conventional dimensional regularization. The methods introduced in this paper represent the first steps in the construction of a unified framework for QCD evolution, which could address collinear physics as well as small $x$ physics and gluon saturation.
[ { "created": "Thu, 18 May 2023 16:08:03 GMT", "version": "v1" } ]
2023-05-19
[ [ "Altinoluk", "Tolga", "" ], [ "Beuf", "Guillaume", "" ], [ "Jalilian-Marian", "Jamal", "" ] ]
We derive the Leading Order DGLAP evolution of gluon distribution function in the target light cone gauge starting from its standard operator definition. The derivation is performed using the background field formalism employed in the Color Glass Condensate effective theory of small $x$ QCD. We adopt Mandelstam-Leibbrandt prescription to regulate in an unambiguous way the spurious singularity appearing in the light-cone gauge Feynman propagator. UV divergences are regulated via conventional dimensional regularization. The methods introduced in this paper represent the first steps in the construction of a unified framework for QCD evolution, which could address collinear physics as well as small $x$ physics and gluon saturation.
hep-ph/0105221
Asmaa Abada
A. Abada, Ph. Boucaud, G. Herdoiza, J.P. Leroy, J. Micheli, O. P\`ene, J. Rodr\'iguez-Quintero
Preliminaries on a Lattice Analysis of The Pion Light-cone Wave function: a Partonic Signal?
23 pages, 21 PS figures, Latex
Phys.Rev.D64:074511,2001
10.1103/PhysRevD.64.074511
LPT Orsay/00-111, UHU-FT/00-03
hep-ph hep-lat
null
We present the first attempt of a new method to compute the pion light-cone wave function (LCWF) on the lattice. We compute the matrix element between the pion and the vacuum of a non-local operator: the propagator of a ``scalar quark'' (named for short "squark"). A theoretical analysis shows that for some kinematical conditions (energetic pion and hard squark) this matrix element depends dominantly on the LCWF $\Phi_\pi(u), u\in [0,1]$. On the lattice, the discretization of the parton momenta imposes further constraints on the pion momentum. The two-point Green functions made of squark-quark and squark-squark fields show hadron-like bound-state behaviour and verify the standard energy spectrum. We show some indications that during a short time, after being created, the system of the spectator quark and the squark behave like partons, before they form a hadron-like bound state. This short time is the place where the partonic wave function has to be looked for.
[ { "created": "Tue, 22 May 2001 09:04:56 GMT", "version": "v1" } ]
2016-08-16
[ [ "Abada", "A.", "" ], [ "Boucaud", "Ph.", "" ], [ "Herdoiza", "G.", "" ], [ "Leroy", "J. P.", "" ], [ "Micheli", "J.", "" ], [ "Pène", "O.", "" ], [ "Rodríguez-Quintero", "J.", "" ] ]
We present the first attempt of a new method to compute the pion light-cone wave function (LCWF) on the lattice. We compute the matrix element between the pion and the vacuum of a non-local operator: the propagator of a ``scalar quark'' (named for short "squark"). A theoretical analysis shows that for some kinematical conditions (energetic pion and hard squark) this matrix element depends dominantly on the LCWF $\Phi_\pi(u), u\in [0,1]$. On the lattice, the discretization of the parton momenta imposes further constraints on the pion momentum. The two-point Green functions made of squark-quark and squark-squark fields show hadron-like bound-state behaviour and verify the standard energy spectrum. We show some indications that during a short time, after being created, the system of the spectator quark and the squark behave like partons, before they form a hadron-like bound state. This short time is the place where the partonic wave function has to be looked for.
hep-ph/9610267
Bernd Kniehl
B.A. Kniehl (MPI Munich), G. Kramer (Hamburg University), M. Spira (CERN)
Large-p_T Photoproduction of D^*+- Mesons in ep Collisions
31 pages (Latex), 13 figures (Postscript). This version of the manuscript is identical with the one being printed in Z. Phys. C
Z.Phys.C76:689-700,1997
10.1007/s002880050591
CERN-TH/96-274, DESY 96-210, MPI/PhT/96-103
hep-ph hep-ex
null
The cross section for the inclusive photoproduction of large-p_T D^*+- mesons is calculated at next-to-leading order, adopting different approaches to describe the fragmentation of charm quarks into D^*+- mesons. We treat the charm quark according to the massless factorization scheme, where it is assumed to be one of the active flavours inside the proton and the photon. We present inclusive single-particle distributions in transverse momentum and rapidity, including the contributions due to both direct and resolved photons. We compare and assess the various implementations of fragmentation. We argue that, in the high-p_T regime, a particularly realistic description can be obtained by convoluting the Altarelli-Parisi-evolved fragmentation functions of Peterson et al. with the hard-scattering cross sections of massless partons where the factorization of the collinear singularities associated with final-state charm quarks is converted to the massive-charm scheme. The predictions thus obtained agree well with recent experimental data by the H1 and ZEUS Collaborations at DESY HERA.
[ { "created": "Mon, 7 Oct 1996 13:13:00 GMT", "version": "v1" }, { "created": "Tue, 17 Jun 1997 12:39:38 GMT", "version": "v2" }, { "created": "Mon, 13 Oct 1997 08:23:18 GMT", "version": "v3" } ]
2014-11-17
[ [ "Kniehl", "B. A.", "", "MPI Munich" ], [ "Kramer", "G.", "", "Hamburg University" ], [ "Spira", "M.", "", "CERN" ] ]
The cross section for the inclusive photoproduction of large-p_T D^*+- mesons is calculated at next-to-leading order, adopting different approaches to describe the fragmentation of charm quarks into D^*+- mesons. We treat the charm quark according to the massless factorization scheme, where it is assumed to be one of the active flavours inside the proton and the photon. We present inclusive single-particle distributions in transverse momentum and rapidity, including the contributions due to both direct and resolved photons. We compare and assess the various implementations of fragmentation. We argue that, in the high-p_T regime, a particularly realistic description can be obtained by convoluting the Altarelli-Parisi-evolved fragmentation functions of Peterson et al. with the hard-scattering cross sections of massless partons where the factorization of the collinear singularities associated with final-state charm quarks is converted to the massive-charm scheme. The predictions thus obtained agree well with recent experimental data by the H1 and ZEUS Collaborations at DESY HERA.
hep-ph/0112033
Carlos Munoz
D.G. Cerdeno, S. Khalil, C. Munoz
Large dark matter cross sections from supergravity and superstrings
Talk given at COSMO-01, Rovaniemi, Finland, August 29-September 4, 2001. Latex, 13 pages, 7 figures
null
null
CERN-TH/2001-345, FTUAM 01/22, IFT-UAM/CSIC-01-38, IPPP/01/57, DCPT/01/112
hep-ph
null
We study the direct detection of supersymmetric dark matter in the light of recent experimental results. In particular, we show that regions in the parameter space of several scenarios with a neutralino-nucleon cross section of the order of $10^{-6}$ pb, i.e., where current dark matter detectors are sensitive, can be obtained. These are supergravity scenarios with intermediate unification scale, and superstring scenarios with D-branes.
[ { "created": "Mon, 3 Dec 2001 17:52:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cerdeno", "D. G.", "" ], [ "Khalil", "S.", "" ], [ "Munoz", "C.", "" ] ]
We study the direct detection of supersymmetric dark matter in the light of recent experimental results. In particular, we show that regions in the parameter space of several scenarios with a neutralino-nucleon cross section of the order of $10^{-6}$ pb, i.e., where current dark matter detectors are sensitive, can be obtained. These are supergravity scenarios with intermediate unification scale, and superstring scenarios with D-branes.
0806.2422
Sugumi Kanno
Sugumi Kanno, Masashi Kimura, Jiro Soda, Shuichiro Yokoyama
Anisotropic Inflation from Vector Impurity
16 pages, 4 figures, improved section V, to be published in JCAP
JCAP0808:034,2008
10.1088/1475-7516/2008/08/034
null
hep-ph astro-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an inflationary scenario with a vector impurity. We show that the universe undergoes anisotropic inflationary expansion due to a preferred direction determined by the vector. Using the slow-roll approximation, we find a formula to determine anisotropy of the inflationary universe. We discuss possible observable predictions of this scenario. In particular, it is stressed that primordial gravitational waves can be induced from curvature perturbations. Hence, even in low scale inflation, a sizable amount of primordial gravitational waves may be produced during inflation.
[ { "created": "Sun, 15 Jun 2008 06:42:28 GMT", "version": "v1" }, { "created": "Wed, 25 Jun 2008 05:39:47 GMT", "version": "v2" }, { "created": "Fri, 1 Aug 2008 14:05:42 GMT", "version": "v3" } ]
2008-11-26
[ [ "Kanno", "Sugumi", "" ], [ "Kimura", "Masashi", "" ], [ "Soda", "Jiro", "" ], [ "Yokoyama", "Shuichiro", "" ] ]
We study an inflationary scenario with a vector impurity. We show that the universe undergoes anisotropic inflationary expansion due to a preferred direction determined by the vector. Using the slow-roll approximation, we find a formula to determine anisotropy of the inflationary universe. We discuss possible observable predictions of this scenario. In particular, it is stressed that primordial gravitational waves can be induced from curvature perturbations. Hence, even in low scale inflation, a sizable amount of primordial gravitational waves may be produced during inflation.
2006.16220
Joshua Foster
Christopher Dessert, Joshua W. Foster, Yonatan Kahn, Benjamin R. Safdi
Systematics in the XENON1T data: the 15-keV anti-axion
9 pages, 7 figures, supplementary code at https://github.com/joshwfoster/XenonSystematics
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The XENON1T collaboration has found an excess of electron recoil events in their Science Run 1 data below ~7 keV with a spectral shape consistent with that expected from a solar-axion-induced signal. The claimed statistical significance of the solar-axion model over the null hypothesis is 3.5$\sigma$. In this work we provide evidence for mismodeling in the electron recoil data that may decrease the local significance of the axion model to as low as $p \approx 0.1$. To reach this conclusion, we search for a signal with the spectral template of the solar axion model, but shifted to higher (unphysical) energies above ~7 keV. We find that the distribution of significances found from this side-band analysis does not follow the expected chi-square distribution, which allows us to quantify the extent to which mismodeling may be affecting the interpretation of the data at energies below ~7 keV. For example, we find that there is an even higher-significance fit to the data when the solar axion model is shifted upwards in energy by ~15 keV and allowed to have a negative normalization.
[ { "created": "Mon, 29 Jun 2020 17:39:14 GMT", "version": "v1" } ]
2020-06-30
[ [ "Dessert", "Christopher", "" ], [ "Foster", "Joshua W.", "" ], [ "Kahn", "Yonatan", "" ], [ "Safdi", "Benjamin R.", "" ] ]
The XENON1T collaboration has found an excess of electron recoil events in their Science Run 1 data below ~7 keV with a spectral shape consistent with that expected from a solar-axion-induced signal. The claimed statistical significance of the solar-axion model over the null hypothesis is 3.5$\sigma$. In this work we provide evidence for mismodeling in the electron recoil data that may decrease the local significance of the axion model to as low as $p \approx 0.1$. To reach this conclusion, we search for a signal with the spectral template of the solar axion model, but shifted to higher (unphysical) energies above ~7 keV. We find that the distribution of significances found from this side-band analysis does not follow the expected chi-square distribution, which allows us to quantify the extent to which mismodeling may be affecting the interpretation of the data at energies below ~7 keV. For example, we find that there is an even higher-significance fit to the data when the solar axion model is shifted upwards in energy by ~15 keV and allowed to have a negative normalization.
2104.12230
Vladimir Baryshevsky
V. G. Baryshevsky, P. I. Porshnev
Predicting outcomes of electric dipole and magnetic moment experiments
null
null
10.1088/1402-4896/ac50c8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The anomalous magnetic and electric dipole moments in spin motion equation acquire pseudoscalar corrections if the $T(CP)$-noninvariance is admitted. It allows to explain the discrepancy between experimental and theoretical values of muon $(g-2)$ factor under assumption that the pseudoscalar correction is the dominant source of this discrepancy.
[ { "created": "Sun, 25 Apr 2021 19:04:37 GMT", "version": "v1" } ]
2022-02-23
[ [ "Baryshevsky", "V. G.", "" ], [ "Porshnev", "P. I.", "" ] ]
The anomalous magnetic and electric dipole moments in spin motion equation acquire pseudoscalar corrections if the $T(CP)$-noninvariance is admitted. It allows to explain the discrepancy between experimental and theoretical values of muon $(g-2)$ factor under assumption that the pseudoscalar correction is the dominant source of this discrepancy.
1005.1224
Mikihiko Nakao
Tobias Hurth and Mikihiko Nakao
Radiative and Electroweak Penguin Decays of B Mesons
Invited contribution to the Annual Review of Nuclear and Particle Science, corrections added based on the published version, 40 pages, 6 figures
Ann.Rev.Nucl.Part.Sci.60:645-677,2010
10.1146/annurev.nucl.012809.104424
MZ-TH/10-07; CERN-PH-TH/2010-068; KEK-PREPRINT-2010-9
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The huge datasets collected at the two B factories, Belle and BaBar, have made it possible to explore the radiative penguin process b --> s gamma, the electroweak penguin process b --> s l+ l- and the suppressed radiative process b --> d gamma in detail, all in exclusive channels and inclusive measurements. Theoretical tools have also advanced to meet or surpass the experimental precision, especially in inclusive calculations and the various ratios of exclusive channels. In this article, we review the theoretical and experimental progress over the past decade in the radiative and electroweak penguin decays of B mesons.
[ { "created": "Fri, 7 May 2010 14:52:00 GMT", "version": "v1" }, { "created": "Fri, 7 Jan 2011 01:51:31 GMT", "version": "v2" } ]
2011-02-18
[ [ "Hurth", "Tobias", "" ], [ "Nakao", "Mikihiko", "" ] ]
The huge datasets collected at the two B factories, Belle and BaBar, have made it possible to explore the radiative penguin process b --> s gamma, the electroweak penguin process b --> s l+ l- and the suppressed radiative process b --> d gamma in detail, all in exclusive channels and inclusive measurements. Theoretical tools have also advanced to meet or surpass the experimental precision, especially in inclusive calculations and the various ratios of exclusive channels. In this article, we review the theoretical and experimental progress over the past decade in the radiative and electroweak penguin decays of B mesons.