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hep-ph/0108208
German Sharov
V. P. Petrov, G. S. Sharov
Special Classes of Solutions for Linear String Baryon Configuration
6 pages, no figures, LaTeX
null
null
TSU-01-21
hep-ph
null
For the linear string baryon model with three material points (three quarks) joined sequentially by the relativistic strings, the class of motions admitting linearizable boundary conditions is investigated. These motions may be represented as the Fourier series with eigenfunctions of some boundary-value problem. The two types of rotational motions are found among the mentioned class of solutions.
[ { "created": "Fri, 24 Aug 2001 17:16:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Petrov", "V. P.", "" ], [ "Sharov", "G. S.", "" ] ]
For the linear string baryon model with three material points (three quarks) joined sequentially by the relativistic strings, the class of motions admitting linearizable boundary conditions is investigated. These motions may be represented as the Fourier series with eigenfunctions of some boundary-value problem. The two types of rotational motions are found among the mentioned class of solutions.
0907.1791
Oscar St{\aa}l
Farvah Mahmoudi, Oscar St{\aa}l
Flavor constraints on two-Higgs-doublet models with general diagonal Yukawa couplings
24 pages, 11 figures. v2: Minor changes to text and numerics, results and conclusions unchanged. References added
Phys.Rev.D81:035016,2010
10.1103/PhysRevD.81.035016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider constraints from flavor physics on two-Higgs-doublet models (2HDM) with general, flavor-diagonal, Yukawa couplings. Analyzing the charged Higgs contribution to different observables, we find that $b\to s\gamma$ transitions and $\Delta M_{B_d}$ restrict the coupling $\lambda_{tt}$ of the top quark (corresponding to $\cot\beta$ in models with a $Z_2$ symmetry) to $|\lambda_{tt}|<1$ for $m_{H^+}\lesssim 500$ GeV. Stringent constraints from $B$ meson decays are obtained also on the other third generation couplings $\lambda_{bb}$ and $\lambda_{\tau\tau}$, but with stronger dependence on $m_{H^+}$. For the second generation, we obtain constraints on combinations of $\lambda_{ss}$, $\lambda_{cc}$, and $\lambda_{\mu\mu}$ from leptonic $K$ and $D_s$ decays. The limits on the general couplings are translated to the common 2HDM types I -- IV with a $Z_2$ symmetry, and presented on the $(m_{H^+},\tan\beta)$ plane. The flavor constraints are most excluding in the type II model which lacks a decoupling limit in $\tan\beta$. We obtain a lower limit $m_{H^+}\gtrsim 300$ GeV in models of type II and III, while no lower bound on $m_{H^+}$ is found for types I and IV.
[ { "created": "Fri, 10 Jul 2009 12:39:06 GMT", "version": "v1" }, { "created": "Thu, 12 Nov 2009 14:45:23 GMT", "version": "v2" } ]
2010-02-19
[ [ "Mahmoudi", "Farvah", "" ], [ "Stål", "Oscar", "" ] ]
We consider constraints from flavor physics on two-Higgs-doublet models (2HDM) with general, flavor-diagonal, Yukawa couplings. Analyzing the charged Higgs contribution to different observables, we find that $b\to s\gamma$ transitions and $\Delta M_{B_d}$ restrict the coupling $\lambda_{tt}$ of the top quark (corresponding to $\cot\beta$ in models with a $Z_2$ symmetry) to $|\lambda_{tt}|<1$ for $m_{H^+}\lesssim 500$ GeV. Stringent constraints from $B$ meson decays are obtained also on the other third generation couplings $\lambda_{bb}$ and $\lambda_{\tau\tau}$, but with stronger dependence on $m_{H^+}$. For the second generation, we obtain constraints on combinations of $\lambda_{ss}$, $\lambda_{cc}$, and $\lambda_{\mu\mu}$ from leptonic $K$ and $D_s$ decays. The limits on the general couplings are translated to the common 2HDM types I -- IV with a $Z_2$ symmetry, and presented on the $(m_{H^+},\tan\beta)$ plane. The flavor constraints are most excluding in the type II model which lacks a decoupling limit in $\tan\beta$. We obtain a lower limit $m_{H^+}\gtrsim 300$ GeV in models of type II and III, while no lower bound on $m_{H^+}$ is found for types I and IV.
hep-ph/9612426
Lisa Randall
Lisa Randall
New Mechanisms of Gauge-Mediated Supersymmetry Breaking
LaTeX, BoxedEPS, 23 pages, 3 figures included
Nucl.Phys.B495:37-56,1997
10.1016/S0550-3213(97)00225-3
MIT-CTP-2591
hep-ph hep-th
null
We introduce new mechanisms for the communication of supersymmetry breaking via gauge interactions. These models do not require complicated dynamics to induce a nonvanishing F term for a singlet. The first class of models communicates supersymmetry breaking to the visible sector through a ``mediator" field that transforms under both a messenger gauge group of the dynamical supersymmetry breaking sector and the standard model gauge group. This model has distinctive phenomenology; in particular, the scalar superpartners should be heavier by at least an order of magnitude than the gaugino superpartners. The second class of models has phenomenology more similar to the ``standard" messenger sectors. A singlet is incorporated, but the model does not require complicated mechanisms to generate a singlet F term. The role of the singlet is to couple fields from the dynamical symmetry breaking sector to fields transforming under the standard model gauge group. We also mention a potential solution to the $\mu$ problem.
[ { "created": "Thu, 19 Dec 1996 23:51:26 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 1996 03:48:01 GMT", "version": "v2" } ]
2016-09-06
[ [ "Randall", "Lisa", "" ] ]
We introduce new mechanisms for the communication of supersymmetry breaking via gauge interactions. These models do not require complicated dynamics to induce a nonvanishing F term for a singlet. The first class of models communicates supersymmetry breaking to the visible sector through a ``mediator" field that transforms under both a messenger gauge group of the dynamical supersymmetry breaking sector and the standard model gauge group. This model has distinctive phenomenology; in particular, the scalar superpartners should be heavier by at least an order of magnitude than the gaugino superpartners. The second class of models has phenomenology more similar to the ``standard" messenger sectors. A singlet is incorporated, but the model does not require complicated mechanisms to generate a singlet F term. The role of the singlet is to couple fields from the dynamical symmetry breaking sector to fields transforming under the standard model gauge group. We also mention a potential solution to the $\mu$ problem.
hep-ph/0609065
Jose Antonio Oller
Jose A. Oller, Joaquim Prades, Michela Verbeni
Aspects of Strangeness -1 Meson-Baryon Scattering
6 figures, 3 figures, talk given in the IVth International Conference on Quarks and Nuclear Physics (QNP06), Madrid June 5th and 10th, 2006. One reference is updated
Eur.Phys.J.A31:527-533,2007
10.1140/epja/i2006-10185-6
null
hep-ph nucl-th
null
We consider meson-baryon interactions in S-wave with strangeness -1. This is a sector populated by plenty of resonances interacting in several two-body coupled channels. We consider a large set of experimental data, where the recent experiments are remarkably accurate. This requires a sound theoretical description to account for all the data and we employ Unitary Chiral Perturbation Theory up to and including O(p^2). The spectroscopy of our solutions is studied within this approach, discussing the rise from the pole content of two \Lambda(1405) resonances and of the \Lambda(1670), \Lambda(1800), \Sigma(1480), \Sigma(1620) and \Sigma(1750). We finally argue about our preferred fit.
[ { "created": "Wed, 6 Sep 2006 17:28:16 GMT", "version": "v1" }, { "created": "Tue, 20 Feb 2007 12:37:45 GMT", "version": "v2" } ]
2008-11-26
[ [ "Oller", "Jose A.", "" ], [ "Prades", "Joaquim", "" ], [ "Verbeni", "Michela", "" ] ]
We consider meson-baryon interactions in S-wave with strangeness -1. This is a sector populated by plenty of resonances interacting in several two-body coupled channels. We consider a large set of experimental data, where the recent experiments are remarkably accurate. This requires a sound theoretical description to account for all the data and we employ Unitary Chiral Perturbation Theory up to and including O(p^2). The spectroscopy of our solutions is studied within this approach, discussing the rise from the pole content of two \Lambda(1405) resonances and of the \Lambda(1670), \Lambda(1800), \Sigma(1480), \Sigma(1620) and \Sigma(1750). We finally argue about our preferred fit.
hep-ph/0207302
Ketevi A. Assamagan
Ketevi A. Assamagan, Aldo Deandrea, Pierre-Antoine Delsart
Search for the lepton flavor violating decay A^0/H^0 --> tau^{+/-} mu^{+/-} at hadron colliders
19 pages, 21 figures. Updated version takes into account the recent results on the muon g-2 measurements. Submitted to Phys. Rev. D. Added minor corrections from a referee
Phys.Rev. D67 (2003) 035001
10.1103/PhysRevD.67.035001
BNL-69300, LYCEN-2002-27, ATL-COM-PHYS-2002-031
hep-ph
null
In the two Higgs doublet model type III and in several other extensions of the Standard Model, there are no discrete symmetries that suppress flavor changing couplings at tree level. The experimental observation of the nu_mu -- nu_tau flavor oscillation may suggest the non-conservation of lepton number. This would lead to the decay of the type A^0/H^0 --> tau^{+/-} mu^{+/-}. We determine the present low energy limit on lepton flavor violating (LFV) couplings from the muon g-2 measurement and discuss the prospects for detecting lepton flavor violating decays at the TeVatron and at the Large Hadron Collider. The achievable bounds on the LFV coupling parameter lambda_{tau mu} are presented.
[ { "created": "Wed, 24 Jul 2002 18:23:08 GMT", "version": "v1" }, { "created": "Mon, 12 Aug 2002 19:03:20 GMT", "version": "v2" }, { "created": "Wed, 14 Aug 2002 14:17:42 GMT", "version": "v3" } ]
2009-11-07
[ [ "Assamagan", "Ketevi A.", "" ], [ "Deandrea", "Aldo", "" ], [ "Delsart", "Pierre-Antoine", "" ] ]
In the two Higgs doublet model type III and in several other extensions of the Standard Model, there are no discrete symmetries that suppress flavor changing couplings at tree level. The experimental observation of the nu_mu -- nu_tau flavor oscillation may suggest the non-conservation of lepton number. This would lead to the decay of the type A^0/H^0 --> tau^{+/-} mu^{+/-}. We determine the present low energy limit on lepton flavor violating (LFV) couplings from the muon g-2 measurement and discuss the prospects for detecting lepton flavor violating decays at the TeVatron and at the Large Hadron Collider. The achievable bounds on the LFV coupling parameter lambda_{tau mu} are presented.
hep-ph/9511328
Vesna Mikuta-Martinis
M. Martinis, and V. Mikuta-Martinis (Rudjer Boskovic Institute, Zagreb, Croatia)
Need for the intensity-dependent pion-nucleon coupling in multipion production processes
18 pages, no figures, latex
null
null
IRB-TH-8/95, submitted to Phys.Rev.D
hep-ph nucl-th
null
We give reasons in support of the use of an effective intensity-dependent pion-nucleon coupling Hamiltonian for describing the properties of the pion multiplicity distribution and the corresponding factorial moments within the thermal-density matrix approach.We explain the appearance of the negative-binomial (NB) distribution for pions and the well-known empi- rical relation of Wroblewski.Our model Hamiltonian is written as a linear combination of the generators of the SU(1,1) group.We find the generating function for the pion multiplicity distribution at finite temperature T and discuss the properties of the second-order factorial moment.Also, we show that an intensity-dependent pion-nucleon coupling generates the squeezed states of the pion field. At T=0, these squeezed states become an inherent property of the NB distribution.
[ { "created": "Wed, 15 Nov 1995 15:46:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Martinis", "M.", "", "Rudjer Boskovic Institute,\n Zagreb, Croatia" ], [ "Mikuta-Martinis", "V.", "", "Rudjer Boskovic Institute,\n Zagreb, Croatia" ] ]
We give reasons in support of the use of an effective intensity-dependent pion-nucleon coupling Hamiltonian for describing the properties of the pion multiplicity distribution and the corresponding factorial moments within the thermal-density matrix approach.We explain the appearance of the negative-binomial (NB) distribution for pions and the well-known empi- rical relation of Wroblewski.Our model Hamiltonian is written as a linear combination of the generators of the SU(1,1) group.We find the generating function for the pion multiplicity distribution at finite temperature T and discuss the properties of the second-order factorial moment.Also, we show that an intensity-dependent pion-nucleon coupling generates the squeezed states of the pion field. At T=0, these squeezed states become an inherent property of the NB distribution.
2001.02421
Hoang Nam Cao
Tran N. Hung, Cao H. Nam
Probing an emergent $U(1)$ extension of the Standard Model at colliders
21 pages, 13 figures, 2 tables; v2: Title changed, Sections III and IV improved significantly, typos corrected, references added, a new author included
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We explore the potential of probing for a new neutral gauge boson that emerges from a topologically nontrivial structure of spacetime, focusing on its couplings to the fermions of the Standard Model. We analyze the current experimental constraints on the mass of the new gauge boson and the radius of the fifth dimension, using the LEP bound and the LHC with 140 $\text{fb}^{-1}$ luminosity. In addition, we investigate the indirect search of the new gauge boson and its discrimination from other hypothetical gauge bosons like those predicted in the $U(1)_{B-L}$ and $U(1)_R$ models by studying the forward-backward, left-right, and left-right-forward-backward asymmetries.
[ { "created": "Wed, 8 Jan 2020 09:25:56 GMT", "version": "v1" }, { "created": "Tue, 21 Mar 2023 04:41:59 GMT", "version": "v2" } ]
2023-03-22
[ [ "Hung", "Tran N.", "" ], [ "Nam", "Cao H.", "" ] ]
We explore the potential of probing for a new neutral gauge boson that emerges from a topologically nontrivial structure of spacetime, focusing on its couplings to the fermions of the Standard Model. We analyze the current experimental constraints on the mass of the new gauge boson and the radius of the fifth dimension, using the LEP bound and the LHC with 140 $\text{fb}^{-1}$ luminosity. In addition, we investigate the indirect search of the new gauge boson and its discrimination from other hypothetical gauge bosons like those predicted in the $U(1)_{B-L}$ and $U(1)_R$ models by studying the forward-backward, left-right, and left-right-forward-backward asymmetries.
0909.2664
A. H. Rezaeian
Amir H. Rezaeian
Nuclear modification factor in p+pb collisions at LHC and saturation
4 pages, 3 figures, talk given at "The 2009 Europhysics Conference on High Energy Physics", 16-22 July 2009, Krakow, Poland
PoS EPS-HEP2009:045,2009
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide predictions for the nuclear modification factor R_{pA} for pions and direct photon production in p+A collisions at LHC energy at midrapidity within different saturation models fitted to HERA data. In our approach we have no free parameters to adjust and all model parameters are fitted to other reactions. Our approach gives a rather good description of PHENIX data for R_{pA} for pions. We show that, in various saturation models, the pion Cronin enhancement is replaced by a moderate suppression at LHC energy at midrapidity due to gluon shadowing effects. However, Cronin enhancement of direct photons can survive at LHC energy in models with a larger saturation scale. We show that both shadowing and saturation effects are important at LHC in p+A collisions and give rise to a rather sizable effect in the nuclear modification factor R_{pA}. Therefore, a precise measurement of p+A collisions at LHC is crucial in order to understand the underlying dynamics of heavy ion collisions.
[ { "created": "Mon, 14 Sep 2009 21:04:38 GMT", "version": "v1" }, { "created": "Wed, 23 Dec 2009 18:16:16 GMT", "version": "v2" } ]
2014-11-20
[ [ "Rezaeian", "Amir H.", "" ] ]
We provide predictions for the nuclear modification factor R_{pA} for pions and direct photon production in p+A collisions at LHC energy at midrapidity within different saturation models fitted to HERA data. In our approach we have no free parameters to adjust and all model parameters are fitted to other reactions. Our approach gives a rather good description of PHENIX data for R_{pA} for pions. We show that, in various saturation models, the pion Cronin enhancement is replaced by a moderate suppression at LHC energy at midrapidity due to gluon shadowing effects. However, Cronin enhancement of direct photons can survive at LHC energy in models with a larger saturation scale. We show that both shadowing and saturation effects are important at LHC in p+A collisions and give rise to a rather sizable effect in the nuclear modification factor R_{pA}. Therefore, a precise measurement of p+A collisions at LHC is crucial in order to understand the underlying dynamics of heavy ion collisions.
2003.06859
Kurosh Javidan
K. Javidan, M. M. Yazdanpanah and H. Nematollahi
Non-Extensive Behaviour of the QCD Strong Coupling Constant
14 pages, 5 figures
Eur. Phys. J. A (2021) 57: 78
10.1140/epja/s10050-021-00391-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The compatibility of theoretically calculated values for the strong coupling constant,through the renormalization group approach with experimental data is studied. There exist considerable divergence in-between theoretical and experimental results at low energies, which can not be explained by thermal field theory and considering chemical potential. Such great deviation can be treated successfully by considering the q-generalized statistical effects through adding a q-nonextensive parameter in the fitting of theoretical results on experimental data.
[ { "created": "Sun, 15 Mar 2020 16:04:26 GMT", "version": "v1" }, { "created": "Sat, 4 Apr 2020 13:30:00 GMT", "version": "v2" } ]
2021-05-28
[ [ "Javidan", "K.", "" ], [ "Yazdanpanah", "M. M.", "" ], [ "Nematollahi", "H.", "" ] ]
The compatibility of theoretically calculated values for the strong coupling constant,through the renormalization group approach with experimental data is studied. There exist considerable divergence in-between theoretical and experimental results at low energies, which can not be explained by thermal field theory and considering chemical potential. Such great deviation can be treated successfully by considering the q-generalized statistical effects through adding a q-nonextensive parameter in the fitting of theoretical results on experimental data.
hep-ph/9708282
Matteo Cacciari
Matteo Cacciari (DESY)
On Heavy Quarks Photoproduction and c -> D* Fragmentation Functions
11 pages, LaTeX, 10 plots included. To appear in the Proceedings of the Ringberg Workshop ``New Trends in HERA Physics'', 25-30 May 1997
null
null
DESY 97-156
hep-ph
null
The state of the art of the theoretical calculations for heavy quarks photoproduction is reviewed. The full fixed order next-to-leading order massive calculation and the resummation of large log(p_T/m) terms for differential cross sections are described. The implementation of a non-perturbative fragmentation function describing the c -> D* meson transition is also discussed.
[ { "created": "Thu, 7 Aug 1997 16:34:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cacciari", "Matteo", "", "DESY" ] ]
The state of the art of the theoretical calculations for heavy quarks photoproduction is reviewed. The full fixed order next-to-leading order massive calculation and the resummation of large log(p_T/m) terms for differential cross sections are described. The implementation of a non-perturbative fragmentation function describing the c -> D* meson transition is also discussed.
0807.2870
Gregory Soyez
S. Munier, G. P. Salam and G. Soyez
Travelling waves and impact-parameter correlations
13 pages, 11 figures; corrected typos
Phys.Rev.D78:054009,2008
10.1103/PhysRevD.78.054009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is usually assumed that the high-energy evolution of partons in QCD remains local in coordinate space. In particular, fixed impact-parameter scattering is thought to be in the universality class of one-dimensional reaction-diffusion processes as if the evolutions at different points in the transverse plane became uncorrelated through rapidity evolution. We check this assumption by numerically comparing a toy model with QCD-like impact-parameter dependence to its exact counterpart with uniform evolution in impact-parameter space. We find quantitative differences, but which seem to amount to a mere rescaling of the strong coupling constant. Since the rescaling factor does not show any strong alpha_s-dependence, we conclude that locality is well verified, up to subleading terms at small alpha_s.
[ { "created": "Thu, 17 Jul 2008 20:21:55 GMT", "version": "v1" }, { "created": "Wed, 3 Sep 2008 13:03:32 GMT", "version": "v2" } ]
2009-01-09
[ [ "Munier", "S.", "" ], [ "Salam", "G. P.", "" ], [ "Soyez", "G.", "" ] ]
It is usually assumed that the high-energy evolution of partons in QCD remains local in coordinate space. In particular, fixed impact-parameter scattering is thought to be in the universality class of one-dimensional reaction-diffusion processes as if the evolutions at different points in the transverse plane became uncorrelated through rapidity evolution. We check this assumption by numerically comparing a toy model with QCD-like impact-parameter dependence to its exact counterpart with uniform evolution in impact-parameter space. We find quantitative differences, but which seem to amount to a mere rescaling of the strong coupling constant. Since the rescaling factor does not show any strong alpha_s-dependence, we conclude that locality is well verified, up to subleading terms at small alpha_s.
hep-ph/9706305
Paige Wheeler
Peter Arnold
B Violation in the Hot Standard Model
16 pages, Latex, all figures included with epsf
null
null
UW/PT 97-15
hep-ph
null
I explain, as simply and pedagogically as I can, recent arguments that the high-temperature baryon number violation rate depends on the electroweak coupling as $\Gamma = # \alpha_\w^5 T^4$ (up to higher order corrections). This is in contrast to the form $\Gamma = # \alpha_\w^4 T^4$ that has historically been assumed in discussions of electroweak baryogenesis. I will give a general analysis of the time scale for non-perturbative gauge field fluctuations in hot non-Abelian plasmas.
[ { "created": "Mon, 9 Jun 1997 20:32:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Arnold", "Peter", "" ] ]
I explain, as simply and pedagogically as I can, recent arguments that the high-temperature baryon number violation rate depends on the electroweak coupling as $\Gamma = # \alpha_\w^5 T^4$ (up to higher order corrections). This is in contrast to the form $\Gamma = # \alpha_\w^4 T^4$ that has historically been assumed in discussions of electroweak baryogenesis. I will give a general analysis of the time scale for non-perturbative gauge field fluctuations in hot non-Abelian plasmas.
1112.0302
Sichun Sun
David B. Kaplan and Sichun Sun
Spacetime as a topological insulator: Mechanism for the origin of the fermion generations
Substantially revised version, to appear in Phys. Rev. Lett
null
10.1103/PhysRevLett.108.181807
INT-PUB-11-061
hep-ph cond-mat.mes-hall hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a mechanism whereby the three generations of quarks and leptons correspond to surface modes in a five-dimensional theory. These modes arise from a nonlinear fermion dispersion relation in the extra dimension, much in the same manner as fermion surface modes in a topological insulator or lattice implementation of domain wall fermions. We also show that the topological properties can persist in a deconstructed version of the model in four dimensions.
[ { "created": "Thu, 1 Dec 2011 20:41:50 GMT", "version": "v1" }, { "created": "Thu, 8 Dec 2011 20:56:57 GMT", "version": "v2" }, { "created": "Fri, 13 Apr 2012 19:24:32 GMT", "version": "v3" } ]
2013-05-30
[ [ "Kaplan", "David B.", "" ], [ "Sun", "Sichun", "" ] ]
We suggest a mechanism whereby the three generations of quarks and leptons correspond to surface modes in a five-dimensional theory. These modes arise from a nonlinear fermion dispersion relation in the extra dimension, much in the same manner as fermion surface modes in a topological insulator or lattice implementation of domain wall fermions. We also show that the topological properties can persist in a deconstructed version of the model in four dimensions.
2310.18972
German F. R. Sborlini
Prasanna K. Dhani, Germ\'an Rodrigo, German F. R. Sborlini
Towards higher-order collinear splittings with massive partons
6 pages. Contribution to the Proceedings of the EPS-HEP 2023 Conference
PoS(EPS-HEP2023)275
null
IFIC/23-47
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
The singularities associated with QCD factorization in the collinear limit are key ingredients for high-precision theoretical predictions in particle physics. They govern the collinear behaviour of scattering amplitudes, as well as the perturbative energy evolution of parton densities (PDFs) and fragmentation functions (FFs). In this talk, we present the computation of multiple collinear and higher-order QCD splittings with massive partons. Our results are highly-relevant for the consistent introduction of mass effects in the subtraction formalism and PDF/FF evolution.
[ { "created": "Sun, 29 Oct 2023 10:42:52 GMT", "version": "v1" } ]
2023-10-31
[ [ "Dhani", "Prasanna K.", "" ], [ "Rodrigo", "Germán", "" ], [ "Sborlini", "German F. R.", "" ] ]
The singularities associated with QCD factorization in the collinear limit are key ingredients for high-precision theoretical predictions in particle physics. They govern the collinear behaviour of scattering amplitudes, as well as the perturbative energy evolution of parton densities (PDFs) and fragmentation functions (FFs). In this talk, we present the computation of multiple collinear and higher-order QCD splittings with massive partons. Our results are highly-relevant for the consistent introduction of mass effects in the subtraction formalism and PDF/FF evolution.
hep-ph/9309252
null
R. Arnowitt and Pran Nath
Testing Supergravity Grand Unification at Future Accelerator and Underground Experiments
7 figures available upon request, CTP-TAMU-32/93, NUB-TH-3066/93 and SSCL-Preprint-440
Phys.Rev.D49:1479-1485,1994
10.1103/PhysRevD.49.1479
null
hep-ph
null
The full parameter space of supergravity grand unified theory with $SU(5)$ type $p \rightarrow \bar{\nu} K$ proton decay is analysed using renormalization group induced electroweak symmetry breaking under the restrictions that the universal scalar mass $m_o$ and gluino mass are $\leq 1$ TeV (no extreme fine tuning) and the Higgs triplet mass obeys $M_{H_3}/M_G < 10$. Future proton decay experiments at SuperKamiokande or ICARUS can reach a sensitivity for the $\bar{\nu} K$ mode of $(2-5) \times 10^{33}$ yr allowing a number of predictions concerning the SUSY mass spectrum. Thus either the $p \rightarrow\bar{\nu} K$ decay mode will be seen at these experiments or a chargino of mass $m_{\tilde{W}} < 100$ GeV will exist and hence be observable at LEP2. Further, if $(p \rightarrow \bar{\nu} K) > 1.5 \times 10^{33}$ yr, then either the light Higgs has mass $m_h \leq 95$ GeV or $m_{\tilde{W}} \leq 100$ GeV i.e. either the light Higgs or the light chargino (or both) would be observable at LEP2. Thus, the combination of future accelerator and future underground experiments allow for strong experimental tests of this theory.
[ { "created": "Fri, 10 Sep 1993 04:39:12 GMT", "version": "v1" } ]
2008-11-26
[ [ "Arnowitt", "R.", "" ], [ "Nath", "Pran", "" ] ]
The full parameter space of supergravity grand unified theory with $SU(5)$ type $p \rightarrow \bar{\nu} K$ proton decay is analysed using renormalization group induced electroweak symmetry breaking under the restrictions that the universal scalar mass $m_o$ and gluino mass are $\leq 1$ TeV (no extreme fine tuning) and the Higgs triplet mass obeys $M_{H_3}/M_G < 10$. Future proton decay experiments at SuperKamiokande or ICARUS can reach a sensitivity for the $\bar{\nu} K$ mode of $(2-5) \times 10^{33}$ yr allowing a number of predictions concerning the SUSY mass spectrum. Thus either the $p \rightarrow\bar{\nu} K$ decay mode will be seen at these experiments or a chargino of mass $m_{\tilde{W}} < 100$ GeV will exist and hence be observable at LEP2. Further, if $(p \rightarrow \bar{\nu} K) > 1.5 \times 10^{33}$ yr, then either the light Higgs has mass $m_h \leq 95$ GeV or $m_{\tilde{W}} \leq 100$ GeV i.e. either the light Higgs or the light chargino (or both) would be observable at LEP2. Thus, the combination of future accelerator and future underground experiments allow for strong experimental tests of this theory.
hep-ph/0512230
Vladimir Galkin
D. Ebert, R. N. Faustov, V. O. Galkin
Masses of heavy tetraquarks in the relativistic quark model
10 pages, 1 figure, minor changes, version to be published in Phys.Lett.B
Phys.Lett. B634 (2006) 214-219
10.1016/j.physletb.2006.01.026
HU-EP-05/82
hep-ph
null
The masses of heavy tetraquarks with hidden charm and bottom are calculated in the framework of the relativistic quark model. The tetraquark is considered as the bound state of a heavy-light diquark and antidiquark. The light quark in a heavy-light diquark is treated completely relativistically. The internal structure of the diquark is taken into account by calculating the diquark-gluon form factor in terms of the diquark wave functions. New experimental data on charmonium-like states above open charm threshold are discussed. The obtained results indicate that the X(3872) can be the tetraquark state with hidden charm. The masses of ground state tetraquarks with hidden bottom are found to be below the open bottom threshold.
[ { "created": "Mon, 19 Dec 2005 11:32:09 GMT", "version": "v1" }, { "created": "Mon, 13 Feb 2006 13:01:11 GMT", "version": "v2" } ]
2009-11-11
[ [ "Ebert", "D.", "" ], [ "Faustov", "R. N.", "" ], [ "Galkin", "V. O.", "" ] ]
The masses of heavy tetraquarks with hidden charm and bottom are calculated in the framework of the relativistic quark model. The tetraquark is considered as the bound state of a heavy-light diquark and antidiquark. The light quark in a heavy-light diquark is treated completely relativistically. The internal structure of the diquark is taken into account by calculating the diquark-gluon form factor in terms of the diquark wave functions. New experimental data on charmonium-like states above open charm threshold are discussed. The obtained results indicate that the X(3872) can be the tetraquark state with hidden charm. The masses of ground state tetraquarks with hidden bottom are found to be below the open bottom threshold.
hep-ph/0211046
Kazumasa Ohkuma
Toshiyuki Morii (Kobe Univ.) and Kazumasa Ohkuma (Yokohama National Univ.)
Charmed Hadron Production in Polarized pp Collisions
1+6 pages, Latex2e, 4 eps figures, Talk given at SPIN 2002, Brookhaven National Laboratory, September 9-13, 2002, To appear in the Proceedings
null
10.1063/1.1607154
KOBE-FHD-02-05, YNU-HEPTH-02-103
hep-ph
null
To extract information about polarized gluons in the proton, production of charmed hadrons, in particular, \Lambda_c^+ baryon in pp collisions was studied. We calculated the transverse momentum distribution and the pseudo-rapidity distribution of the spin correlation asymmetry A_{LL} between the initial proton and the produced \Lambda_c^+. Those statistical sensitivities were also calculated under the condition of RHIC experiment. We found that the pseudo-rapidity distribution of A_{LL} is promising for testing the model of polarized gluons in the proton and also the spin-dependent fragmentation model of a charm quark decaying into \Lambda_c^+ baryon.
[ { "created": "Tue, 5 Nov 2002 05:51:04 GMT", "version": "v1" } ]
2009-11-07
[ [ "Morii", "Toshiyuki", "", "Kobe Univ." ], [ "Ohkuma", "Kazumasa", "", "Yokohama National\n Univ." ] ]
To extract information about polarized gluons in the proton, production of charmed hadrons, in particular, \Lambda_c^+ baryon in pp collisions was studied. We calculated the transverse momentum distribution and the pseudo-rapidity distribution of the spin correlation asymmetry A_{LL} between the initial proton and the produced \Lambda_c^+. Those statistical sensitivities were also calculated under the condition of RHIC experiment. We found that the pseudo-rapidity distribution of A_{LL} is promising for testing the model of polarized gluons in the proton and also the spin-dependent fragmentation model of a charm quark decaying into \Lambda_c^+ baryon.
hep-ph/9608280
Kurt Riesselmann
Kurt Riesselmann and Scott Willenbrock
Ruling Out a Strongly-Interacting Standard Higgs Model
29 pages, 6 figures. The complete paper including figures is also available via WWW at http://www.physik.tu-muenchen.de/tumphy/d/T30d/PAPERS/TUM-HEP-236-96.ps.gz
Phys.Rev.D55:311-321,1997
10.1103/PhysRevD.55.311
TUM-HEP-236/96, ILL-(TH)-96-4
hep-ph hep-lat
null
Previous work has suggested that perturbation theory is unreliable for Higgs- and Goldstone-boson scattering, at energies above the Higgs mass, for relatively small values of the Higgs quartic coupling $\lambda(\mu)$. By performing a summation of nonlogarithmic terms, we show that perturbation theory is in fact reliable up to relatively large coupling. This eliminates the possibility of a strongly-interacting standard Higgs model at energies above the Higgs mass, complementing earlier studies which excluded strong interactions at energies near the Higgs mass. The summation can be formulated in terms of an appropriate scale in the running coupling, $\mu=\sqrt{s}/e\approx\sqrt{s}/2.7$, so it can easily be incorporated in renormalization-group improved tree-level amplitudes as well as higher-order calculations.
[ { "created": "Fri, 9 Aug 1996 11:56:44 GMT", "version": "v1" } ]
2014-11-17
[ [ "Riesselmann", "Kurt", "" ], [ "Willenbrock", "Scott", "" ] ]
Previous work has suggested that perturbation theory is unreliable for Higgs- and Goldstone-boson scattering, at energies above the Higgs mass, for relatively small values of the Higgs quartic coupling $\lambda(\mu)$. By performing a summation of nonlogarithmic terms, we show that perturbation theory is in fact reliable up to relatively large coupling. This eliminates the possibility of a strongly-interacting standard Higgs model at energies above the Higgs mass, complementing earlier studies which excluded strong interactions at energies near the Higgs mass. The summation can be formulated in terms of an appropriate scale in the running coupling, $\mu=\sqrt{s}/e\approx\sqrt{s}/2.7$, so it can easily be incorporated in renormalization-group improved tree-level amplitudes as well as higher-order calculations.
1510.04949
Jaume Tarr\'us
Jaume Tarr\'us Castell\`a
Heavy hybrids in pNRQCD
Proceedings for the conference Quark Confinement and the Hadron spectrum XI
null
null
TUM-EFT 59/14
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report on the calculation of the Quarkonium Hybrid masses for the $cg\bar{c}$, $bg\bar{c}$ and $bg\bar{b}$ systems~\cite{hbrpaper}. A QCD analog of the Born-Oppenheimer approximation including the $\Lambda$--doubling terms has been used. The gluonic static energies are obtained combining the short range description from potential non--relativistic QCD (pNRQCD) and lattice QCD calculations. The effect $\Lambda$--doubling terms is to mix the contributions of the static energies to the hybrid states leading to the break of the degeneracy between spin symmetry multiplets with opposite parity. The spin symmetry multiplets with mixed contributions from different static energies have a lower mass with respect to the parity opposite that remains without mixed contributions. We compare with direct lattice calculations and discuss several experimental candidates.
[ { "created": "Fri, 16 Oct 2015 17:06:55 GMT", "version": "v1" } ]
2015-10-23
[ [ "Castellà", "Jaume Tarrús", "" ] ]
We report on the calculation of the Quarkonium Hybrid masses for the $cg\bar{c}$, $bg\bar{c}$ and $bg\bar{b}$ systems~\cite{hbrpaper}. A QCD analog of the Born-Oppenheimer approximation including the $\Lambda$--doubling terms has been used. The gluonic static energies are obtained combining the short range description from potential non--relativistic QCD (pNRQCD) and lattice QCD calculations. The effect $\Lambda$--doubling terms is to mix the contributions of the static energies to the hybrid states leading to the break of the degeneracy between spin symmetry multiplets with opposite parity. The spin symmetry multiplets with mixed contributions from different static energies have a lower mass with respect to the parity opposite that remains without mixed contributions. We compare with direct lattice calculations and discuss several experimental candidates.
2111.09895
Joel Doss
Timothy Cohen, Joel Doss, Xiaochuan Lu
Unitarity Bounds on Effective Field Theories at the LHC
38 pages + appendix, 21 figures
null
10.1007/JHEP04(2022)155
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective Field Theory (EFT) extensions of the Standard Model are tools to compute observables $\big(e.g.$ cross sections with partonic center-of-mass energy $\sqrt{\hat{s}}\,\big)$ as a systematically improvable expansion suppressed by a new physics scale $M$. If one is interested in EFT predictions in the parameter space where $M<\sqrt{\hat{s}}$, concerns of self-consistency emerge, which can manifest as a violation of perturbative partial-wave unitarity. However, when we search for the effects of an EFT at a hadron collider with center-of-mass energy $\sqrt{s}$ using an inclusive strategy, we typically do not have access to the event-by-event value of $\sqrt{\hat{s}}$. This motivates the need for a formalism that incorporates parton distribution functions into the perturbative partial-wave unitarity analysis. Developing such a framework and initiating an exploration of its implications is the goal of this work. Our approach opens up a potentially valid region of the EFT parameter space where $M \ll \sqrt{s}$. We provide evidence that there exist valid EFTs in this parameter space. The perturbative unitarity bounds are sensitive to the details of a given search, an effect we investigate by varying kinematic cuts.
[ { "created": "Thu, 18 Nov 2021 19:00:05 GMT", "version": "v1" }, { "created": "Mon, 6 Jun 2022 17:05:08 GMT", "version": "v2" } ]
2022-06-07
[ [ "Cohen", "Timothy", "" ], [ "Doss", "Joel", "" ], [ "Lu", "Xiaochuan", "" ] ]
Effective Field Theory (EFT) extensions of the Standard Model are tools to compute observables $\big(e.g.$ cross sections with partonic center-of-mass energy $\sqrt{\hat{s}}\,\big)$ as a systematically improvable expansion suppressed by a new physics scale $M$. If one is interested in EFT predictions in the parameter space where $M<\sqrt{\hat{s}}$, concerns of self-consistency emerge, which can manifest as a violation of perturbative partial-wave unitarity. However, when we search for the effects of an EFT at a hadron collider with center-of-mass energy $\sqrt{s}$ using an inclusive strategy, we typically do not have access to the event-by-event value of $\sqrt{\hat{s}}$. This motivates the need for a formalism that incorporates parton distribution functions into the perturbative partial-wave unitarity analysis. Developing such a framework and initiating an exploration of its implications is the goal of this work. Our approach opens up a potentially valid region of the EFT parameter space where $M \ll \sqrt{s}$. We provide evidence that there exist valid EFTs in this parameter space. The perturbative unitarity bounds are sensitive to the details of a given search, an effect we investigate by varying kinematic cuts.
0804.3182
Heinrich Leutwyler
H. Leutwyler
Model independent determination of the sigma pole
10 pages, 4 figures, Contribution to the proceedings of the Workshop on Scalar Mesons and Related Topics, honouring the 70th birthday of Michael Scadron, Lisbon, Portugal, Feb. 11-16, 2008
AIPConf.Proc.1030:46-55,2008
10.1063/1.2973552
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first part of this report reviews recent developments at the interface between lattice work on QCD with light dynamical quarks, effective field theory and low energy precision experiments. Then I discuss how dispersion theory can be used to analyze the low energy structure of the $\pi\pi$ scattering amplitude in a model independent manner. This leads to an exact formula for the mass and width of the lowest few resonances, in terms of observable quantities. As an application, I consider the pole position of the $\sigma$, paying particular to error propagation in the numerical analysis. The report is based on work done in collaboration with Irinel Caprini and Gilberto Colangelo.
[ { "created": "Sun, 20 Apr 2008 10:16:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Leutwyler", "H.", "" ] ]
The first part of this report reviews recent developments at the interface between lattice work on QCD with light dynamical quarks, effective field theory and low energy precision experiments. Then I discuss how dispersion theory can be used to analyze the low energy structure of the $\pi\pi$ scattering amplitude in a model independent manner. This leads to an exact formula for the mass and width of the lowest few resonances, in terms of observable quantities. As an application, I consider the pole position of the $\sigma$, paying particular to error propagation in the numerical analysis. The report is based on work done in collaboration with Irinel Caprini and Gilberto Colangelo.
1510.07421
Marc Schlegel
Marc Schlegel, Patriz Hinderer, Werner Vogelsang
NLO K-factors for Single-Inclusive Leptoproduction of Hadrons
10 pages, 8 figures, contribution to the proceedings of QCD Evolution 2015, Jefferson Lab, Newport News, Virginia, USA, May 26-30, 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings we discuss next-to-leading order (NLO) perturbative-QCD calculations of the cross section for the process $\ell N\to h X$. We briefly present the main features of the calculation and in particular analyze the role of quasi-real photons that enter the processes because the scattered lepton is not observed. We find that the NLO corrections are sizable for the spin-averaged cross section. In order to quantify this statement we present the K-factors of the cross sections for fixed target experiments HERMES, JLab12 and COMPASS.
[ { "created": "Mon, 26 Oct 2015 09:34:35 GMT", "version": "v1" } ]
2015-10-27
[ [ "Schlegel", "Marc", "" ], [ "Hinderer", "Patriz", "" ], [ "Vogelsang", "Werner", "" ] ]
In these proceedings we discuss next-to-leading order (NLO) perturbative-QCD calculations of the cross section for the process $\ell N\to h X$. We briefly present the main features of the calculation and in particular analyze the role of quasi-real photons that enter the processes because the scattered lepton is not observed. We find that the NLO corrections are sizable for the spin-averaged cross section. In order to quantify this statement we present the K-factors of the cross sections for fixed target experiments HERMES, JLab12 and COMPASS.
hep-ph/9706397
Edmond Iancu
Jean-Paul Blaizot and Edmond Iancu, Service de Physique Theorique, Saclay, France
The Bloch-Nordsieck propagator at finite temperature
LaTex file, 35 pages, 6 eps figures included
Phys. Rev. D 56, 7877 (1997)
10.1103/PhysRevD.56.7877
Saclay-T97/052
hep-ph
null
We have shown recently that the resummation of soft photon contributions leads to a non-exponential decay of the fermion excitations in hot QED plasmas. The retarded propagator of a massless fermion was found to behave as $S_R(t >> 1/gT) \sim \exp{-\alpha T t [\ln(\omega_p t) + C]}$, where $\omega_p=gT/3$ is the plasma frequency, $\alpha=g^2/4\pi$, and $C$ is a constant, independent of $g$, which was left undefined. This term is computed in this paper. In gauges with unphysical degrees of freedom, it is gauge-fixing independent provided an infrared regulator is introduced in the gauge sector. We also extend our analysis to hot QCD and express the quark and gluon propagators in the form of three-dimensional Euclidean functional integrals which may be evaluated on the lattice.
[ { "created": "Wed, 18 Jun 1997 10:22:09 GMT", "version": "v1" } ]
2016-08-25
[ [ "Blaizot", "Jean-Paul", "" ], [ "Iancu", "Edmond", "" ], [ "Theorique", "Service de Physique", "" ], [ "Saclay", "", "" ], [ "France", "", "" ] ]
We have shown recently that the resummation of soft photon contributions leads to a non-exponential decay of the fermion excitations in hot QED plasmas. The retarded propagator of a massless fermion was found to behave as $S_R(t >> 1/gT) \sim \exp{-\alpha T t [\ln(\omega_p t) + C]}$, where $\omega_p=gT/3$ is the plasma frequency, $\alpha=g^2/4\pi$, and $C$ is a constant, independent of $g$, which was left undefined. This term is computed in this paper. In gauges with unphysical degrees of freedom, it is gauge-fixing independent provided an infrared regulator is introduced in the gauge sector. We also extend our analysis to hot QCD and express the quark and gluon propagators in the form of three-dimensional Euclidean functional integrals which may be evaluated on the lattice.
hep-ph/0202181
Mr Qiang Zhao
Frank E. Close and Qiang Zhao
Pedagogic model for Deeply Virtual Compton Scattering with quark-hadron duality
Version accepted by Phys. Rev. D
Phys.Rev. D66 (2002) 054001
10.1103/PhysRevD.66.054001
null
hep-ph nucl-th
null
We show how quark-hadron duality can emerge for valence spin averaged structure functions, and for the non-forward distributions of Deeply Virtual Compton Scattering. Novel factorisations of the non-forward amplitudes are proposed. Some implications for large angle scattering and deviations from the quark counting rules are illustrated.
[ { "created": "Tue, 19 Feb 2002 10:37:33 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 2002 13:49:41 GMT", "version": "v2" } ]
2009-11-07
[ [ "Close", "Frank E.", "" ], [ "Zhao", "Qiang", "" ] ]
We show how quark-hadron duality can emerge for valence spin averaged structure functions, and for the non-forward distributions of Deeply Virtual Compton Scattering. Novel factorisations of the non-forward amplitudes are proposed. Some implications for large angle scattering and deviations from the quark counting rules are illustrated.
hep-ph/9705320
Tom Browder
T.E. Browder (University of Hawaii), A. Datta (Iowa State University), X.-G. He (University of Melbourne), and S. Pakvasa (University of Hawaii)
CP Violation in Quasi-inclusive $B\to K^{(*)} X$ Decays
28 pages, REVTEX format with 20 figures. Updated acknowledgments. Corrected typographical errors and updated the bibliography. To appear in Physical Review D
Phys.Rev.D57:6829-6842,1998
10.1103/PhysRevD.57.6829
UH 511-864-96, AMES-HET-97-05
hep-ph hep-ex
null
We consider the possibility of observing CP violation in quasi-inclusive decays of the type $B^-\to K^- X$, $B^-\to K^{*-} X$, $\bar B^0\to K^- X$ and $\bar B^0\to K^{*-} X$, where $X$ does not contain strange quarks. We present estimates of rates and asymmetries for these decays in the Standard Model and comment on the experimental feasibility of observing CP violation in these decays at future $B$ factories. We find the rate asymmetries can be quite sizeable.
[ { "created": "Wed, 14 May 1997 23:55:31 GMT", "version": "v1" }, { "created": "Fri, 16 May 1997 02:02:38 GMT", "version": "v2" }, { "created": "Tue, 14 Apr 1998 00:03:45 GMT", "version": "v3" } ]
2014-11-17
[ [ "Browder", "T. E.", "", "University of Hawaii" ], [ "Datta", "A.", "", "Iowa State University" ], [ "He", "X. -G.", "", "University of Melbourne" ], [ "Pakvasa", "S.", "", "University of Hawaii" ] ]
We consider the possibility of observing CP violation in quasi-inclusive decays of the type $B^-\to K^- X$, $B^-\to K^{*-} X$, $\bar B^0\to K^- X$ and $\bar B^0\to K^{*-} X$, where $X$ does not contain strange quarks. We present estimates of rates and asymmetries for these decays in the Standard Model and comment on the experimental feasibility of observing CP violation in these decays at future $B$ factories. We find the rate asymmetries can be quite sizeable.
hep-ph/0212234
Marcio Jose Menon
R. F. \'Avila, E. G. S. Luna, and M. J. Menon
Analytic models and forward scattering from accelerator to cosmic-ray energies
16 pages, 7 figures, aps-revtex, wording changes, corrected typos, to appear in Physical Review D
Phys.Rev. D67 (2003) 054020
10.1103/PhysRevD.67.054020
null
hep-ph hep-ex hep-th
null
Analytic models for hadron-hadron scattering are characterized by analytical parametrizations for the forward amplitudes and the use of dispersion relation techniques to study the total cross section $\sigma_{tot}$ and the $\rho$ parameter. In this paper we investigate four aspects related to the application of the model to $pp$ and $\bar{p}p$ scattering, from accelerator to cosmic-ray energies: 1) the effect of different estimations for $\sigma_{tot}$ from cosmic-ray experiments; 2) the differences between individual and global (simultaneous) fits to $\sigma_{tot}$ and $\rho$; 3) the role of the subtraction constant in the dispersion relations; 4) the effect of distinct asymptotic inputs from different analytic models. This is done by using as a framework the single Pomeron and the maximal Odderon parametrizations for the total cross section. Our main conclusions are the following: 1) Despite the small influence from different cosmic-ray estimations, the results allow us to extract an upper bound for the soft pomeron intercept: $1 + \epsilon = 1.094$; 2) although global fits present good statistical results, in general, this procedure constrains the rise of $\sigma_{tot}$; 3) the subtraction constant as a free parameter affects the fit results at both low and high energies; 4) independently of the cosmic-ray information used and the subtraction constant, global fits with the odderon parametrization predict that, above $\sqrt s \approx 70$ GeV, $\rho_{pp}(s)$ becomes greater than $\rho_{\bar{p}p}(s)$, and this result is in complete agreement with all the data presently available. In particular, we infer $\rho_{pp} = 0.134 \pm 0.005$ at $\sqrt s = 200$ GeV and $0.151 \pm 0.007$ at 500 GeV (BNL RHIC energies).
[ { "created": "Mon, 16 Dec 2002 22:09:47 GMT", "version": "v1" }, { "created": "Wed, 19 Mar 2003 17:50:48 GMT", "version": "v2" } ]
2009-11-07
[ [ "Ávila", "R. F.", "" ], [ "Luna", "E. G. S.", "" ], [ "Menon", "M. J.", "" ] ]
Analytic models for hadron-hadron scattering are characterized by analytical parametrizations for the forward amplitudes and the use of dispersion relation techniques to study the total cross section $\sigma_{tot}$ and the $\rho$ parameter. In this paper we investigate four aspects related to the application of the model to $pp$ and $\bar{p}p$ scattering, from accelerator to cosmic-ray energies: 1) the effect of different estimations for $\sigma_{tot}$ from cosmic-ray experiments; 2) the differences between individual and global (simultaneous) fits to $\sigma_{tot}$ and $\rho$; 3) the role of the subtraction constant in the dispersion relations; 4) the effect of distinct asymptotic inputs from different analytic models. This is done by using as a framework the single Pomeron and the maximal Odderon parametrizations for the total cross section. Our main conclusions are the following: 1) Despite the small influence from different cosmic-ray estimations, the results allow us to extract an upper bound for the soft pomeron intercept: $1 + \epsilon = 1.094$; 2) although global fits present good statistical results, in general, this procedure constrains the rise of $\sigma_{tot}$; 3) the subtraction constant as a free parameter affects the fit results at both low and high energies; 4) independently of the cosmic-ray information used and the subtraction constant, global fits with the odderon parametrization predict that, above $\sqrt s \approx 70$ GeV, $\rho_{pp}(s)$ becomes greater than $\rho_{\bar{p}p}(s)$, and this result is in complete agreement with all the data presently available. In particular, we infer $\rho_{pp} = 0.134 \pm 0.005$ at $\sqrt s = 200$ GeV and $0.151 \pm 0.007$ at 500 GeV (BNL RHIC energies).
1611.07956
Zurab Tavartkiladze
Avtandil Achelashvili, Zurab Tavartkiladze
Calculable Cosmological CP Violation and Resonant Leptogenesis
Appendix B, on RH sneutrino contribution to the baryon asymmetry, added. Clarifying discussions and references added
Phys. Rev. D 96, 015015 (2017)
10.1103/PhysRevD.96.015015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the extension of MSSM by two right handed neutrinos, which masses are degenerate at tree level, we address the issue of leptogenesis. Investigating the quantum corrections in details, we show that the lepton asymmetry is induced at 1-loop level and decisive role is played by the tau lepton Yukawa coupling. On a concrete and predictive neutrino model, which enables to predict the CP violating $\delta $ phase and relate it to the cosmological CP asymmetry, we demonstrate that the needed amount of the baryon asymmetry is generated via the resonant leptogenesis.
[ { "created": "Wed, 23 Nov 2016 19:57:37 GMT", "version": "v1" }, { "created": "Tue, 29 Nov 2016 20:41:21 GMT", "version": "v2" }, { "created": "Mon, 12 Jun 2017 11:31:23 GMT", "version": "v3" } ]
2017-07-26
[ [ "Achelashvili", "Avtandil", "" ], [ "Tavartkiladze", "Zurab", "" ] ]
Within the extension of MSSM by two right handed neutrinos, which masses are degenerate at tree level, we address the issue of leptogenesis. Investigating the quantum corrections in details, we show that the lepton asymmetry is induced at 1-loop level and decisive role is played by the tau lepton Yukawa coupling. On a concrete and predictive neutrino model, which enables to predict the CP violating $\delta $ phase and relate it to the cosmological CP asymmetry, we demonstrate that the needed amount of the baryon asymmetry is generated via the resonant leptogenesis.
hep-ph/0305204
Robert Harlander
Robert Harlander and William Kilgore
Techniques for NNLO Higgs production in the Standard Model and the MSSM
4 pages, LaTeX, 4 ps-files included. Talk presented at the XXXVIIIth Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, France, March 22-29, 2003
null
null
BNL-HET-03/11, CERN-TH/2003-112
hep-ph
null
New techniques developed in connection with the NNLO corrections to the Higgs production rate at hadron colliders and some recent applications are reviewed.
[ { "created": "Mon, 19 May 2003 09:05:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Harlander", "Robert", "" ], [ "Kilgore", "William", "" ] ]
New techniques developed in connection with the NNLO corrections to the Higgs production rate at hadron colliders and some recent applications are reviewed.
1111.3258
Chun-Yu Cui
Chun-Yu Cui, Yong-Lu Liu and Ming-Qiu Huang
$B^{\ast}_{s1}B^{\ast}K$ form factor from QCD sum rules
12 pages, 6 figures. arXiv admin note: text overlap with arXiv:1009.5320 by other authors
Phys.Lett.B707:129-136,2012
10.1016/j.physletb.2011.12.022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we calculate the form factors and the coupling constant of the $g_{B^{\ast}_{s1}B^{\ast} K}$ vertex in the framework of the three-point QCD sum rules. Three point correlation functions responsible for the vertex are evaluated by considering both $B^{\ast}$ and $K$ mesons as off-shell states. The form factors obtained are different if the $B^{\ast}$ or the $K$ meson is off-shell but give the same coupling constant.
[ { "created": "Mon, 14 Nov 2011 16:00:35 GMT", "version": "v1" }, { "created": "Thu, 24 Nov 2011 18:02:40 GMT", "version": "v2" }, { "created": "Wed, 18 Apr 2012 09:50:59 GMT", "version": "v3" } ]
2012-04-19
[ [ "Cui", "Chun-Yu", "" ], [ "Liu", "Yong-Lu", "" ], [ "Huang", "Ming-Qiu", "" ] ]
In this article, we calculate the form factors and the coupling constant of the $g_{B^{\ast}_{s1}B^{\ast} K}$ vertex in the framework of the three-point QCD sum rules. Three point correlation functions responsible for the vertex are evaluated by considering both $B^{\ast}$ and $K$ mesons as off-shell states. The form factors obtained are different if the $B^{\ast}$ or the $K$ meson is off-shell but give the same coupling constant.
1612.06094
George Lazarides
G. Lazarides, C. Panagiotakopoulos, Q.Shafi
Axion, mu Term, and Supersymmetric Hybrid Inflation
11 pages including 6 figures, uses Revtex, version published in Phys. Rev. D
null
10.1103/PhysRevD.95.055017
UT-STPD-16/02
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how successful supersymmetric hybrid inflation is realized in realistic models where the resolution of the minimal supersymmetric standard model mu problem is intimately linked with axion physics. The scalar fields that accompany the axion, such as the saxion, are closely monitored during and after inflation to ensure that the axion isocurvature perturbations lie below the observational limits. The scalar spectral index n_s is about 0.96 - 0.97, while the tensor-to-scalar ratio r, a canonical measure of gravity waves, lies well below the observable range in our example. The axion domain walls are inflated away, and depending on the axion decay constant f_a and the magnitude of the mu parameter, the axions and/or the lightest supersymmetric particle compose the dark matter in the universe. Non-thermal leptogenesis is naturally implemented in this class of models.
[ { "created": "Mon, 19 Dec 2016 09:51:45 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2017 07:38:50 GMT", "version": "v2" } ]
2017-04-05
[ [ "Lazarides", "G.", "" ], [ "Panagiotakopoulos", "C.", "" ], [ "Shafi", "Q.", "" ] ]
We show how successful supersymmetric hybrid inflation is realized in realistic models where the resolution of the minimal supersymmetric standard model mu problem is intimately linked with axion physics. The scalar fields that accompany the axion, such as the saxion, are closely monitored during and after inflation to ensure that the axion isocurvature perturbations lie below the observational limits. The scalar spectral index n_s is about 0.96 - 0.97, while the tensor-to-scalar ratio r, a canonical measure of gravity waves, lies well below the observable range in our example. The axion domain walls are inflated away, and depending on the axion decay constant f_a and the magnitude of the mu parameter, the axions and/or the lightest supersymmetric particle compose the dark matter in the universe. Non-thermal leptogenesis is naturally implemented in this class of models.
1811.06059
Juan Yepes
Juan Yepes
Top partners tackling vector dark matter
10 pages, 9 figures
Physics Letters B 811 (2020) 135890
10.1016/j.physletb.2020.135890
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The WIMP-nucleon scattering cross section in a simple dark matter model and its constraints from the latest direct detection experiment are treated here at the loop level. We consider a scenario with an emerging vector dark matter field that interacts with the Standard Model quarks, via loop contributions that are sourced from a scalar mediator. The involved parameter space for the dark matter-mediator masses is constrained by the Xenon1T limit and the neutrino floor. The current direct detection bounds are eluded by invoking the top partners in a Composite Higgs model, whose scale mass helps us in suppressing the WIMP-nucleon cross section.
[ { "created": "Wed, 14 Nov 2018 20:52:32 GMT", "version": "v1" }, { "created": "Fri, 20 Nov 2020 00:11:55 GMT", "version": "v2" } ]
2020-11-23
[ [ "Yepes", "Juan", "" ] ]
The WIMP-nucleon scattering cross section in a simple dark matter model and its constraints from the latest direct detection experiment are treated here at the loop level. We consider a scenario with an emerging vector dark matter field that interacts with the Standard Model quarks, via loop contributions that are sourced from a scalar mediator. The involved parameter space for the dark matter-mediator masses is constrained by the Xenon1T limit and the neutrino floor. The current direct detection bounds are eluded by invoking the top partners in a Composite Higgs model, whose scale mass helps us in suppressing the WIMP-nucleon cross section.
hep-ph/0110417
Jamal Jalilian-Marian
Jamal Jalilian-Marian (BNL) and Sangyong Jeon (McGill University and RBRC)
Probing Gluons in Nuclei: the Case of $\eta'$
16 pages, 3 figures
Phys.Rev. C65 (2002) 065201
10.1103/PhysRevC.65.065201
null
hep-ph nucl-th
null
Using the recently proposed $gg --> eta'$ effective vertex, we investigate the production of $\eta'$ from gluon fusion in $pA$ collisions. We show that measuring $\eta'$ production cross-section at moderate $x_{\eta'}$ yields direct information on the small $x$ gluon distribution function of the nucleus. At RHIC, the smallest accessible $x$ turns out to be $O(10^{-5})$ and at LHC, it is $O(10^{-8})$. Therefore, $\eta'$ is an excellent probe of the Color Glass Condensate.
[ { "created": "Wed, 31 Oct 2001 19:09:00 GMT", "version": "v1" } ]
2009-11-07
[ [ "Jalilian-Marian", "Jamal", "", "BNL" ], [ "Jeon", "Sangyong", "", "McGill University and\n RBRC" ] ]
Using the recently proposed $gg --> eta'$ effective vertex, we investigate the production of $\eta'$ from gluon fusion in $pA$ collisions. We show that measuring $\eta'$ production cross-section at moderate $x_{\eta'}$ yields direct information on the small $x$ gluon distribution function of the nucleus. At RHIC, the smallest accessible $x$ turns out to be $O(10^{-5})$ and at LHC, it is $O(10^{-8})$. Therefore, $\eta'$ is an excellent probe of the Color Glass Condensate.
1303.5553
Oleg Selyugin
O.V. Selyugin
Generalized hadron structure and elastic scattering
6 pages, 4 figures, talk on the ASI "Symmetries and Spin", Prague
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The new parameterization of the Generalized Parton Distributions (GPDs) t-dependence is investigated. It is shown that the new form of the GPDS allows one to reproduce sufficiently well the electromagnetic form factors of the proton and neutron at small and large momentum transfer and obtain a good description of the elastic nucleon-nucleon scattering at high energies.
[ { "created": "Fri, 22 Mar 2013 09:23:57 GMT", "version": "v1" } ]
2013-03-25
[ [ "Selyugin", "O. V.", "" ] ]
The new parameterization of the Generalized Parton Distributions (GPDs) t-dependence is investigated. It is shown that the new form of the GPDS allows one to reproduce sufficiently well the electromagnetic form factors of the proton and neutron at small and large momentum transfer and obtain a good description of the elastic nucleon-nucleon scattering at high energies.
1603.08913
Adrian Carmona
Adrian Carmona
A 750 GeV graviton from holographic composite dark sectors
9 pages, 9 figures; v2: revised and improved analysis, discussion on the interplay with the radion dynamics added, matches version accepted in Physics Letters B
null
10.1016/j.physletb.2016.07.040
CERN-TH-2016-073
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the 750 GeV di-photon excess can be interpreted as a spin-2 resonance arising from a strongly interacting dark sector featuring some departure from conformality. This spin-2 resonance has negligible couplings to the SM particles, with the exception of the SM gauge bosons which mediate between the two sectors. We have explicitly studied the collider constraints as well as some theoretical bounds in a holographic five dimensional model with a warp factor that deviates from AdS$_5$. In particular, we have shown that it is not possible to decouple the vector resonances arising from the strong sector while explaining the di-photon anomaly and keeping the five dimensional gravity theory under perturbative control. However, vector resonances with masses around the TeV scale can be present while all experimental constraints are met.
[ { "created": "Tue, 29 Mar 2016 19:50:10 GMT", "version": "v1" }, { "created": "Mon, 18 Jul 2016 10:25:45 GMT", "version": "v2" } ]
2016-08-24
[ [ "Carmona", "Adrian", "" ] ]
We show that the 750 GeV di-photon excess can be interpreted as a spin-2 resonance arising from a strongly interacting dark sector featuring some departure from conformality. This spin-2 resonance has negligible couplings to the SM particles, with the exception of the SM gauge bosons which mediate between the two sectors. We have explicitly studied the collider constraints as well as some theoretical bounds in a holographic five dimensional model with a warp factor that deviates from AdS$_5$. In particular, we have shown that it is not possible to decouple the vector resonances arising from the strong sector while explaining the di-photon anomaly and keeping the five dimensional gravity theory under perturbative control. However, vector resonances with masses around the TeV scale can be present while all experimental constraints are met.
hep-ph/0006131
Alessandro Bacchetta
A. Bacchetta, P.J. Mulders (Free University of Amsterdam)
Semi-inclusive vector meson production in DIS
3 pages, uses sprocl.sty, talk given at the DIS2000 conference, Liverpool, England, April 2000, to appear in the conference proceedings
null
null
VUTH 00-15
hep-ph
null
We analyze one-particle inclusive DIS in the case when a spin-1 hadron (such as a vector meson) is observed in the final state. We consider only leading order contributions in 1/Q, but we include transverse momentum of partons. Several new fragmentation functions appear in cross sections. One of them can be measured in connection with the transverse-spin disbtribution function h_1.
[ { "created": "Tue, 13 Jun 2000 11:56:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bacchetta", "A.", "", "Free University of Amsterdam" ], [ "Mulders", "P. J.", "", "Free University of Amsterdam" ] ]
We analyze one-particle inclusive DIS in the case when a spin-1 hadron (such as a vector meson) is observed in the final state. We consider only leading order contributions in 1/Q, but we include transverse momentum of partons. Several new fragmentation functions appear in cross sections. One of them can be measured in connection with the transverse-spin disbtribution function h_1.
0903.1971
Seong Chan Park
Chuan-Ren Chen, Mihoko M. Nojiri, Seong Chan Park, Jing Shu and Michihisa Takeuchi
Dark matter and collider phenomenology of split-UED
32 pages, 15 figures
JHEP 0909:078,2009
10.1088/1126-6708/2009/09/078
IPMU08-0023, YITP-09-16, KEK-TH-1306
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explicitly show that split-universal extra dimension (split-UED), a recently suggested extension of universal extra dimension (UED) model, can nicely explain recent anomalies in cosmic-ray positrons and electrons observed by PAMELA and ATIC/PPB-BETS. Kaluza-Klein (KK) dark matters mainly annihilate into leptons because the hadronic branching fraction is highly suppressed by large KK quark masses and the antiproton flux agrees very well with the observation where no excess is found . The flux of cosmic gamma-rays from pion decay is also highly suppressed and hardly detected in low energy region (E<20 GeV). Collider signatures of colored KK particles at the LHC, especially q_1 q_1 production, are studied in detail. Due to the large split in masses of KK quarks and other particles, hard p_T jets and missing E_T are generated, which make it possible to suppress the standard model background and discover the signals.
[ { "created": "Wed, 11 Mar 2009 13:48:52 GMT", "version": "v1" } ]
2014-11-18
[ [ "Chen", "Chuan-Ren", "" ], [ "Nojiri", "Mihoko M.", "" ], [ "Park", "Seong Chan", "" ], [ "Shu", "Jing", "" ], [ "Takeuchi", "Michihisa", "" ] ]
We explicitly show that split-universal extra dimension (split-UED), a recently suggested extension of universal extra dimension (UED) model, can nicely explain recent anomalies in cosmic-ray positrons and electrons observed by PAMELA and ATIC/PPB-BETS. Kaluza-Klein (KK) dark matters mainly annihilate into leptons because the hadronic branching fraction is highly suppressed by large KK quark masses and the antiproton flux agrees very well with the observation where no excess is found . The flux of cosmic gamma-rays from pion decay is also highly suppressed and hardly detected in low energy region (E<20 GeV). Collider signatures of colored KK particles at the LHC, especially q_1 q_1 production, are studied in detail. Due to the large split in masses of KK quarks and other particles, hard p_T jets and missing E_T are generated, which make it possible to suppress the standard model background and discover the signals.
1305.4756
Guo-Li Wang
Guo-Li Wang, Yue Jiang, Tianhong Wang, Wan-Li Ju
The Properties of $D^{*}_{s1}(2700)^{+}$
12 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The new particle $D^{*}_{s1}(2700)^{+}$ has stimulated many attentions. There are different assignments of its inherent properties. It may be a $2^3S_1$, $1^3D_1$ or the mixture of $2^3S_1-1^3D_1$ $c\bar s$ $1^-$ state. By considering its mass, decay modes, full width, production rate, and comparing with current experimental data, we point out that there is another more reasonable assignment: $D^{*}_{s1}(2700)^{+}$ could be identified as two resonances, one of which is a $2^3S_1$ state, another is a 1D state, and both are $c\bar s$ $1^-$ states. The two states have very close masses, which are around 2700 MeV, and both have broad decay widths. So in experiments, the overlapping of $DK$ or $D^*K$ invariant mass distribution coming from their decays is found, but the current experiments could not distinguish these two resonances and reported one particle.
[ { "created": "Tue, 21 May 2013 08:41:06 GMT", "version": "v1" } ]
2013-05-22
[ [ "Wang", "Guo-Li", "" ], [ "Jiang", "Yue", "" ], [ "Wang", "Tianhong", "" ], [ "Ju", "Wan-Li", "" ] ]
The new particle $D^{*}_{s1}(2700)^{+}$ has stimulated many attentions. There are different assignments of its inherent properties. It may be a $2^3S_1$, $1^3D_1$ or the mixture of $2^3S_1-1^3D_1$ $c\bar s$ $1^-$ state. By considering its mass, decay modes, full width, production rate, and comparing with current experimental data, we point out that there is another more reasonable assignment: $D^{*}_{s1}(2700)^{+}$ could be identified as two resonances, one of which is a $2^3S_1$ state, another is a 1D state, and both are $c\bar s$ $1^-$ states. The two states have very close masses, which are around 2700 MeV, and both have broad decay widths. So in experiments, the overlapping of $DK$ or $D^*K$ invariant mass distribution coming from their decays is found, but the current experiments could not distinguish these two resonances and reported one particle.
1008.2317
Wojciech Broniowski
Wojciech Broniowski, Enrique Ruiz Arriola
Pion transition form factor in the Regge approach
10 pages, talk presented by WB at Light Cone 2010, Valencia, 14-18 June 2010
PoS LC2010:062,2010
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the BaBar puzzle within the Regge approach. After reviewing the chiral quark models in applications to PDF and PDA of the pion, we argue that variants of these models, fulfilling the chiral anomaly, may in fact violate the second Terazawa-West unitarity bound, which is based on unverified assumptions for the real part of the amplitude. Consequently, the transition form factor need not vanish at large values of the photon virtuality. Then we show that the experimental data may be properly explained with incomplete vector-meson dominance in a simple model with one state, as well as in more sophisticated radial Regge models including infinitely many states. We also consider the experimental constraint from the rare Z -> pi0 gamma decay, which is comfortably satisfied in our approach. Finally, we point out that the photon momentum asymmetry parameter may noticeably influence the precision fits to the data.
[ { "created": "Fri, 13 Aug 2010 13:44:31 GMT", "version": "v1" }, { "created": "Tue, 21 Sep 2010 09:12:59 GMT", "version": "v2" } ]
2011-03-10
[ [ "Broniowski", "Wojciech", "" ], [ "Arriola", "Enrique Ruiz", "" ] ]
We explore the BaBar puzzle within the Regge approach. After reviewing the chiral quark models in applications to PDF and PDA of the pion, we argue that variants of these models, fulfilling the chiral anomaly, may in fact violate the second Terazawa-West unitarity bound, which is based on unverified assumptions for the real part of the amplitude. Consequently, the transition form factor need not vanish at large values of the photon virtuality. Then we show that the experimental data may be properly explained with incomplete vector-meson dominance in a simple model with one state, as well as in more sophisticated radial Regge models including infinitely many states. We also consider the experimental constraint from the rare Z -> pi0 gamma decay, which is comfortably satisfied in our approach. Finally, we point out that the photon momentum asymmetry parameter may noticeably influence the precision fits to the data.
1608.06578
Maxime Gouzevitch
Alexandra Carvalho, Martino Dall'Osso, Pablo de Castro Manzano, Tommaso Dorigo, Florian Goertz, Maxime Gouzevich and Mia Tosi
Analytical parametrization and shape classification of anomalous HH production in the EFT approach
20 pages, 10 figures, LHC Higgs Cross Section Working Group report http://cds.cern.ch/record/2199287
null
null
LHCHXSWG-2016-001
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this document we study the effect of anomalous Higgs boson couplings on non-resonant pair production of Higgs bosons ($HH$) at the LHC. We explore the space of the five parameters $\kappa_{\lambda}$, $\kappa_{t}$, $c_2$, $c_g$, and $c_{2g}$ in terms of the corresponding kinematics of the final state, and describe a partition of the space into a limited number of regions featuring similar phenomenology in the kinematics of $HH$ final state. We call clusters the sets of points belonging to the same region; to each cluster corresponds a representative point which we call a benchmark. We discuss a possible technique to estimate the sensitivity of an experimental search to the kinematical differences between the phenomenology of the benchmark points and the rest of the parameter space contained in the corresponding cluster. We also provide an analytical parametrization of the cross-section modifications that the variation of anomalous couplings produces with respect to standard model $HH$ production along with a recipe to translate the results into other parameter-space bases. Finally, we provide a preliminary analysis of variations in the topology of the final state within each region based on recent LHC results.
[ { "created": "Tue, 19 Jul 2016 21:21:03 GMT", "version": "v1" } ]
2016-08-24
[ [ "Carvalho", "Alexandra", "" ], [ "Dall'Osso", "Martino", "" ], [ "Manzano", "Pablo de Castro", "" ], [ "Dorigo", "Tommaso", "" ], [ "Goertz", "Florian", "" ], [ "Gouzevich", "Maxime", "" ], [ "Tosi", "Mia", ...
In this document we study the effect of anomalous Higgs boson couplings on non-resonant pair production of Higgs bosons ($HH$) at the LHC. We explore the space of the five parameters $\kappa_{\lambda}$, $\kappa_{t}$, $c_2$, $c_g$, and $c_{2g}$ in terms of the corresponding kinematics of the final state, and describe a partition of the space into a limited number of regions featuring similar phenomenology in the kinematics of $HH$ final state. We call clusters the sets of points belonging to the same region; to each cluster corresponds a representative point which we call a benchmark. We discuss a possible technique to estimate the sensitivity of an experimental search to the kinematical differences between the phenomenology of the benchmark points and the rest of the parameter space contained in the corresponding cluster. We also provide an analytical parametrization of the cross-section modifications that the variation of anomalous couplings produces with respect to standard model $HH$ production along with a recipe to translate the results into other parameter-space bases. Finally, we provide a preliminary analysis of variations in the topology of the final state within each region based on recent LHC results.
hep-ph/0305210
J. T. Londergan
A. Gardestig, A.P. Szczepaniak, and J.T. Londergan
Separation of Soft and Hard Physics in Deeply Virtual Compton Scattering
14 pages, 5 figures
Phys.Rev. D68 (2003) 034005
10.1103/PhysRevD.68.034005
null
hep-ph
null
A model for deeply virtual Compton scattering, based on analytical light-cone hadron wave functions is presented and studied at energies currently accessible at Jefferson Laboratory, DESY, and beyond. It is shown that perpendicular vector components play an important role at Q^2 < 10 GeV^2 and that the meson-exchange diagrams are important at all energies. This could significantly impact the physical interpretation of the underlying hadron amplitudes.
[ { "created": "Mon, 19 May 2003 16:03:00 GMT", "version": "v1" } ]
2009-11-10
[ [ "Gardestig", "A.", "" ], [ "Szczepaniak", "A. P.", "" ], [ "Londergan", "J. T.", "" ] ]
A model for deeply virtual Compton scattering, based on analytical light-cone hadron wave functions is presented and studied at energies currently accessible at Jefferson Laboratory, DESY, and beyond. It is shown that perpendicular vector components play an important role at Q^2 < 10 GeV^2 and that the meson-exchange diagrams are important at all energies. This could significantly impact the physical interpretation of the underlying hadron amplitudes.
hep-ph/0211129
Francesco Caravaglios
Francesco Caravaglios
Looking for new solutions to the hierarchy problem
14 pages, 1 figure
null
null
null
hep-ph hep-th
null
While in first and second quantization the fundamental operators are respectively coordinates and fields (functions), an extension of quantum field theory can be achieved if the usual pair of conjugate momenta is represented by functionals. After a brief introduction on the hierarchy problem, we show how the ordinary quantum field theory can arise from a specific limit of this extension. We will also show how this extension can offer new solutions to the hierarchy problem. The peculiarity that makes this scenario appealing (as possible solution of the hierarchy problem), is the absence of new light particles at (or close to) the electroweak scale. This is in much better agreement with the experimental observation, since (until now) all searches for new physics signals have confirmed the remarkable success of the Standard Model (contrary to common expectations).
[ { "created": "Sat, 9 Nov 2002 10:06:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Caravaglios", "Francesco", "" ] ]
While in first and second quantization the fundamental operators are respectively coordinates and fields (functions), an extension of quantum field theory can be achieved if the usual pair of conjugate momenta is represented by functionals. After a brief introduction on the hierarchy problem, we show how the ordinary quantum field theory can arise from a specific limit of this extension. We will also show how this extension can offer new solutions to the hierarchy problem. The peculiarity that makes this scenario appealing (as possible solution of the hierarchy problem), is the absence of new light particles at (or close to) the electroweak scale. This is in much better agreement with the experimental observation, since (until now) all searches for new physics signals have confirmed the remarkable success of the Standard Model (contrary to common expectations).
2007.12866
Feng Yuan
Xiaohui Liu, Felix Ringer, Werner Vogelsang, Feng Yuan
Lepton-jet Correlation in Deep Inelastic Scattering
10 pages, 5 figures
Phys. Rev. D 102, 094022 (2020)
10.1103/PhysRevD.102.094022
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the lepton-jet correlation in deep inelastic scattering. We perform one-loop calculations for the spin averaged and transverse spin dependent differential cross sections depending on the total transverse momentum of the final state lepton and the jet. The transverse momentum dependent (TMD) factorization formalism is applied to describe the relevant observables. To show the physics reach of this process, we perform a phenomenological study for HERA kinematics and comment on an ongoing analysis of experimental data. In addition, we highlight the potential of this process to constrain small-$x$ dynamics.
[ { "created": "Sat, 25 Jul 2020 06:26:09 GMT", "version": "v1" } ]
2020-11-25
[ [ "Liu", "Xiaohui", "" ], [ "Ringer", "Felix", "" ], [ "Vogelsang", "Werner", "" ], [ "Yuan", "Feng", "" ] ]
We study the lepton-jet correlation in deep inelastic scattering. We perform one-loop calculations for the spin averaged and transverse spin dependent differential cross sections depending on the total transverse momentum of the final state lepton and the jet. The transverse momentum dependent (TMD) factorization formalism is applied to describe the relevant observables. To show the physics reach of this process, we perform a phenomenological study for HERA kinematics and comment on an ongoing analysis of experimental data. In addition, we highlight the potential of this process to constrain small-$x$ dynamics.
0810.1016
Lijun Zhu
Kaustubh Agashe, Aleksandr Azatov and Lijun Zhu
Flavor Violation Tests of Warped/Composite SM in the Two-Site Approach
46 pages with 10 figures
null
10.1103/PhysRevD.79.056006
UMD-PP-08-015
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study flavor violation in the quark sector in a purely 4D, two-site effective field theory description of the Standard Model and just their first Kaluza-Klein excitations from a warped extra dimension. The warped 5D framework can provide solutions to both the Planck-weak and flavor hierarchies of the SM. It is also related (via the AdS/CFT correspondence) to partial compositeness of the SM. We focus on the dominant contributions in the two-site model to two observables which we argue provide the strongest flavor constraints, namely, epsilon_K and BR(b -> s gamma), where contributions in the two-site model occur at tree and loop-level, respectively. In particular, we demonstrate that a "tension" exists between these two observables in the sense that they have opposite dependence on composite site Yukawa couplings, making it difficult to decouple flavor-violating effects using this parameter. We choose the size of the composite site QCD coupling based on the relation of the two-site model to the 5D model (addressing the Planck-weak hierarchy), where we match the 5D QCD coupling to the 4D coupling at the loop-level and assuming negligible tree-level brane-localized kinetic terms. We estimate that a larger size of the 5D gauge coupling is constrained by the requirement of 5D perturbativity. We find that \sim O(5) TeV mass scale for the new particles in the two-site model can then be consistent with both observables. We also compare our analysis of epsilon_K in the two-site model to that in 5D models, including both the cases of a brane-localized and bulk Higgs.
[ { "created": "Mon, 6 Oct 2008 19:42:19 GMT", "version": "v1" }, { "created": "Fri, 31 Oct 2008 22:05:47 GMT", "version": "v2" } ]
2009-11-13
[ [ "Agashe", "Kaustubh", "" ], [ "Azatov", "Aleksandr", "" ], [ "Zhu", "Lijun", "" ] ]
We study flavor violation in the quark sector in a purely 4D, two-site effective field theory description of the Standard Model and just their first Kaluza-Klein excitations from a warped extra dimension. The warped 5D framework can provide solutions to both the Planck-weak and flavor hierarchies of the SM. It is also related (via the AdS/CFT correspondence) to partial compositeness of the SM. We focus on the dominant contributions in the two-site model to two observables which we argue provide the strongest flavor constraints, namely, epsilon_K and BR(b -> s gamma), where contributions in the two-site model occur at tree and loop-level, respectively. In particular, we demonstrate that a "tension" exists between these two observables in the sense that they have opposite dependence on composite site Yukawa couplings, making it difficult to decouple flavor-violating effects using this parameter. We choose the size of the composite site QCD coupling based on the relation of the two-site model to the 5D model (addressing the Planck-weak hierarchy), where we match the 5D QCD coupling to the 4D coupling at the loop-level and assuming negligible tree-level brane-localized kinetic terms. We estimate that a larger size of the 5D gauge coupling is constrained by the requirement of 5D perturbativity. We find that \sim O(5) TeV mass scale for the new particles in the two-site model can then be consistent with both observables. We also compare our analysis of epsilon_K in the two-site model to that in 5D models, including both the cases of a brane-localized and bulk Higgs.
1806.08719
Maxim Dvornikov
Maxim Dvornikov (1, 2, 3) ((1) IZMIRAN, (2) Tomsk State University, (3) Nordita)
Spin-flavor oscillations of Dirac neutrinos in a plane electromagnetic wave
23 pages in LaTeX2e, 23 eps figures; paper was significantly extended, new Sec. 5 was added, several new figures and references were included; version published in PRD
Phys. Rev. D 98, 075025 (2018)
10.1103/PhysRevD.98.075025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study spin and spin-flavor oscillations of Dirac neutrinos in a plane electromagnetic wave with circular polarization. The evolution of massive neutrinos with nonzero magnetic moments in the field of an electromagnetic wave is based on the exact solution of the Dirac-Pauli equation. We formulate the initial condition problem to describe spin-flavor oscillations in an electromagnetic wave. The transition probabilities for spin and spin-flavor oscillations are obtained. In case of spin-flavor oscillations, we analyze the transition and survival probabilities for different neutrino magnetic moments and various channels of neutrino oscillations. As an application of the obtained results, we study the possibility of existence of $\nu_{e\mathrm{L}}\to\nu_{\mu\mathrm{R}}$ oscillations in an electromagnetic wave emitted by a highly magnetized neutron star. Our results are compared with findings of other authors.
[ { "created": "Fri, 22 Jun 2018 15:16:03 GMT", "version": "v1" }, { "created": "Tue, 30 Oct 2018 17:18:10 GMT", "version": "v2" } ]
2018-11-01
[ [ "Dvornikov", "Maxim", "" ] ]
We study spin and spin-flavor oscillations of Dirac neutrinos in a plane electromagnetic wave with circular polarization. The evolution of massive neutrinos with nonzero magnetic moments in the field of an electromagnetic wave is based on the exact solution of the Dirac-Pauli equation. We formulate the initial condition problem to describe spin-flavor oscillations in an electromagnetic wave. The transition probabilities for spin and spin-flavor oscillations are obtained. In case of spin-flavor oscillations, we analyze the transition and survival probabilities for different neutrino magnetic moments and various channels of neutrino oscillations. As an application of the obtained results, we study the possibility of existence of $\nu_{e\mathrm{L}}\to\nu_{\mu\mathrm{R}}$ oscillations in an electromagnetic wave emitted by a highly magnetized neutron star. Our results are compared with findings of other authors.
1812.11513
Mikolaj Misiak
M. Misiak, M. Paraskevas, J. Rosiek, K. Suxho and B. Zglinicki
Effective Field Theories in R_xi gauges
16 pages, no figures
null
10.1007/JHEP02(2019)051
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In effective quantum field theories, higher dimensional operators can affect the canonical normalization of kinetic terms at tree level. These contributions for scalars and gauge bosons should be carefully included in the gauge fixing procedure, in order to end up with a convenient set of Feynman rules. We develop such a setup for the linear R_xi-gauges. It involves a suitable reduction of the operator basis, a generalized gauge fixing term, and a corresponding ghost sector. Our approach extends previous results for the dimension-six Standard Model Effective Field Theory to a generic class of effective theories with operators of arbitrary dimension.
[ { "created": "Sun, 30 Dec 2018 11:23:18 GMT", "version": "v1" } ]
2019-02-20
[ [ "Misiak", "M.", "" ], [ "Paraskevas", "M.", "" ], [ "Rosiek", "J.", "" ], [ "Suxho", "K.", "" ], [ "Zglinicki", "B.", "" ] ]
In effective quantum field theories, higher dimensional operators can affect the canonical normalization of kinetic terms at tree level. These contributions for scalars and gauge bosons should be carefully included in the gauge fixing procedure, in order to end up with a convenient set of Feynman rules. We develop such a setup for the linear R_xi-gauges. It involves a suitable reduction of the operator basis, a generalized gauge fixing term, and a corresponding ghost sector. Our approach extends previous results for the dimension-six Standard Model Effective Field Theory to a generic class of effective theories with operators of arbitrary dimension.
hep-ph/9912428
Sedigheh Deldar
Sedigheh Deldar
Potentials between static SU(3) sources in the fat-center-vortices model
Compare to the previosly archived edition, I have extended the work to include various classes of vortex flux distribution which has resulted in some interesting new results on the relevance of the flux distributions for the physical consequences of the model. This version corresponds to the published version
JHEP 0101:013,2001
10.1088/1126-6708/2001/01/013
null
hep-ph hep-lat
null
The potentials between static sources in various representaions in SU(3) are calculated based on the fat-center-vortices model of Faber, Greensite and Olejnik. At intermediate distances, most distributions of the flux within vortices lead to potentials that are qualitatively in agreement with ``Casimir scaling,'' which says that the string tension is proportional to the quadratic operator of the representation. However, at the quantitative level, violations of Casimir scaling are generally much larger than those seen in numerical simulations, indicating that additional physical input to the fat-center-vortices model is required. At large distances, screening occurs for zero-triality representations; for the representations with non-zero triality the string tension equals that of the fundamental representation. Some rather ``unphysical,'' flux distributions can lead to violations of Casimir scaling at intermediate distances and violations of the expected ordering of representations at large distances.
[ { "created": "Mon, 20 Dec 1999 18:56:42 GMT", "version": "v1" }, { "created": "Thu, 22 Nov 2001 07:47:00 GMT", "version": "v2" } ]
2010-02-03
[ [ "Deldar", "Sedigheh", "" ] ]
The potentials between static sources in various representaions in SU(3) are calculated based on the fat-center-vortices model of Faber, Greensite and Olejnik. At intermediate distances, most distributions of the flux within vortices lead to potentials that are qualitatively in agreement with ``Casimir scaling,'' which says that the string tension is proportional to the quadratic operator of the representation. However, at the quantitative level, violations of Casimir scaling are generally much larger than those seen in numerical simulations, indicating that additional physical input to the fat-center-vortices model is required. At large distances, screening occurs for zero-triality representations; for the representations with non-zero triality the string tension equals that of the fundamental representation. Some rather ``unphysical,'' flux distributions can lead to violations of Casimir scaling at intermediate distances and violations of the expected ordering of representations at large distances.
1112.3538
Elizabeth H. Simmons
Elizabeth H. Simmons, R. Sekhar Chivukula, Baradhwaj Coleppa, Heather E. Logan, Adam Martin
Topcolor in the LHC Era
15 pages, 5 figures. Contribution to KMI Inauguration Conference "Quest for the Origin of Particles and the Universe" (KMIIN), 24-26 Nov. 2011, KMI, Nagoya University
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ongoing LHC searches for the standard model Higgs Boson in WW or ZZ decay modes strongly constrain the top-Higgs state predicted in many models with new dynamics that preferentially affects top quarks. Such a state couples strongly to top-quarks, and is therefore produced through gluon fusion at a rate that can be greatly enhanced relative to the rate for the standard model Higgs boson. As we discuss in this talk, a top-Higgs state with mass less than 300 GeV is excluded at 95% CL if the associated top-pion has a mass of 150 GeV, and the constraint is even stronger if the mass of the top-pion state exceeds the top-quark mass or if the top-pion decay constant is a substantial fraction of the weak scale. These results have significant implications for theories with strong top dynamics, such as topcolor-assisted technicolor, top-seesaw models, and certain Higgsless models.
[ { "created": "Thu, 15 Dec 2011 15:27:34 GMT", "version": "v1" } ]
2011-12-16
[ [ "Simmons", "Elizabeth H.", "" ], [ "Chivukula", "R. Sekhar", "" ], [ "Coleppa", "Baradhwaj", "" ], [ "Logan", "Heather E.", "" ], [ "Martin", "Adam", "" ] ]
Ongoing LHC searches for the standard model Higgs Boson in WW or ZZ decay modes strongly constrain the top-Higgs state predicted in many models with new dynamics that preferentially affects top quarks. Such a state couples strongly to top-quarks, and is therefore produced through gluon fusion at a rate that can be greatly enhanced relative to the rate for the standard model Higgs boson. As we discuss in this talk, a top-Higgs state with mass less than 300 GeV is excluded at 95% CL if the associated top-pion has a mass of 150 GeV, and the constraint is even stronger if the mass of the top-pion state exceeds the top-quark mass or if the top-pion decay constant is a substantial fraction of the weak scale. These results have significant implications for theories with strong top dynamics, such as topcolor-assisted technicolor, top-seesaw models, and certain Higgsless models.
1405.1551
A. D. Polosa
L. Maiani, F. Piccinini, A. D. Polosa and V. Riquer
The Z(4430) and a New Paradigm for Spin Interactions in Tetraquarks
17 pages, 1 figure, comments added, typos corrected, to appear in Phys Rev D
null
10.1103/PhysRevD.89.114010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Following the recent confirmation of the Z+(4430) resonance with J^{PG}=1^{++}, we have re-examined the model of S- and P-wave tetraquarks. We propose a `type-II' diquark-antidiquark model which shows to be very effective at producing a simple and comprehensive picture of the J^{PG}=1^{++} and 1^{--} sectors of the recently discovered charged tetraquarks and of the observed Y resonances. The model is still faced with the unresolved difficulty of explaining why some states seem to have incomplete isospin multiplets.
[ { "created": "Wed, 7 May 2014 09:56:44 GMT", "version": "v1" }, { "created": "Sat, 17 May 2014 10:05:06 GMT", "version": "v2" } ]
2015-06-19
[ [ "Maiani", "L.", "" ], [ "Piccinini", "F.", "" ], [ "Polosa", "A. D.", "" ], [ "Riquer", "V.", "" ] ]
Following the recent confirmation of the Z+(4430) resonance with J^{PG}=1^{++}, we have re-examined the model of S- and P-wave tetraquarks. We propose a `type-II' diquark-antidiquark model which shows to be very effective at producing a simple and comprehensive picture of the J^{PG}=1^{++} and 1^{--} sectors of the recently discovered charged tetraquarks and of the observed Y resonances. The model is still faced with the unresolved difficulty of explaining why some states seem to have incomplete isospin multiplets.
hep-ph/0512063
Euro Spallucci
Alex Casanova, Euro Spallucci
TeV Mini Black Hole Decay at Future Colliders
22 pages, 9 figures, 4 tables; ``quick review'' for Class. and Quantum Grav
Class.Quant.Grav.23:R45-R62,2006
10.1088/0264-9381/23/3/R01
null
hep-ph
null
It is generally believed that mini black holes decay by emitting elementary particles with a black body energy spectrum. The original calculation lead to the conclusion that about the 90% of the black hole mass is radiated away in the form of photons, neutrinos and light leptons, mainly electrons and muons. With the advent of String Theory, such a scenario must be updated by including new effects coming from the stringy nature of particles and interactions.By taking for granted that black holes can be produced in hadronic collisions, then their decay must take into account that: (i) we live in a D3-Brane embedded into an higher dimensional bulk spacetime; (ii) fundamental interactions, including gravity, are unified at TeV energy scale. Thus, the formal description of the Hawking radiation mechanism has to be extended to the case of more than four spacetime dimensions and include the presence of D-branes. Furthermore, unification of fundamental interactions at an energy scale many order of magnitude lower than the Planck energy implies that any kind of fundamental particle, not only leptons, is expected to be emitted. A detailed understanding of the new scenario is instrumental for optimal tuning of detectors at future colliders, where, hopefully, this exciting new physics will be tested. In this article we review higher dimensional black hole decay, considering not only the emission of particles according to Hawking mechanism, but also their near horizon QED/QCD interactions. The ultimate motivation is to build up a phenomenologically reliable scenario, allowing a clear experimental signature of the event.
[ { "created": "Mon, 5 Dec 2005 12:36:51 GMT", "version": "v1" } ]
2009-11-11
[ [ "Casanova", "Alex", "" ], [ "Spallucci", "Euro", "" ] ]
It is generally believed that mini black holes decay by emitting elementary particles with a black body energy spectrum. The original calculation lead to the conclusion that about the 90% of the black hole mass is radiated away in the form of photons, neutrinos and light leptons, mainly electrons and muons. With the advent of String Theory, such a scenario must be updated by including new effects coming from the stringy nature of particles and interactions.By taking for granted that black holes can be produced in hadronic collisions, then their decay must take into account that: (i) we live in a D3-Brane embedded into an higher dimensional bulk spacetime; (ii) fundamental interactions, including gravity, are unified at TeV energy scale. Thus, the formal description of the Hawking radiation mechanism has to be extended to the case of more than four spacetime dimensions and include the presence of D-branes. Furthermore, unification of fundamental interactions at an energy scale many order of magnitude lower than the Planck energy implies that any kind of fundamental particle, not only leptons, is expected to be emitted. A detailed understanding of the new scenario is instrumental for optimal tuning of detectors at future colliders, where, hopefully, this exciting new physics will be tested. In this article we review higher dimensional black hole decay, considering not only the emission of particles according to Hawking mechanism, but also their near horizon QED/QCD interactions. The ultimate motivation is to build up a phenomenologically reliable scenario, allowing a clear experimental signature of the event.
hep-ph/9703393
Hrachia M. Asatrian
H. M. Asatrian, G. K. Yeghiyan, A. N. Ioannissian
CP-Violation in b Quark Radiative Inclusive Decays
PACS 13.25.Hw, 12.15.Ji, published
Phys. Lett. B399 (1997) 303
10.1016/S0370-2693(97)00297-9
IC/96/193
hep-ph
null
The direct CP-violations in $SU(2)_{L}\times SU(2)_{R} \times U(1)$ model and two-Higgs doublet extension of the standard model for $b \to d\gamma$ and $b \to s\gamma$ decays are investigated. The calculated value of CP-asymmetry for these two models and for $b \to d\gamma$ and $b \to s\gamma$ decays for the wide range of parameters may exceed the value, predicted by the standard model and has a sign opposite to that of the latter.
[ { "created": "Sun, 23 Mar 1997 12:19:53 GMT", "version": "v1" }, { "created": "Tue, 23 Sep 1997 05:32:48 GMT", "version": "v2" } ]
2009-10-30
[ [ "Asatrian", "H. M.", "" ], [ "Yeghiyan", "G. K.", "" ], [ "Ioannissian", "A. N.", "" ] ]
The direct CP-violations in $SU(2)_{L}\times SU(2)_{R} \times U(1)$ model and two-Higgs doublet extension of the standard model for $b \to d\gamma$ and $b \to s\gamma$ decays are investigated. The calculated value of CP-asymmetry for these two models and for $b \to d\gamma$ and $b \to s\gamma$ decays for the wide range of parameters may exceed the value, predicted by the standard model and has a sign opposite to that of the latter.
1407.6608
Max Zoller
Max F. Zoller
Three-loop beta function for the Higgs self-coupling
Contribution to the proceedings of the Loops and Legs 2014 conference
PoS(LL2014)014
null
TTP14-021, SFB/CPP-14-40
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the last two years the renormalization group functions for the couplings and fields of the Standard Model have been computed at three-loop level. The evolution of the self-coupling $\lambda$ of the Standard Model Higgs boson is of particular importance due to its close connection with the stability of the Standard Model vacuum state. In this talk the three-loop corrections to the $\beta$-function for this crucial coupling are discussed. The calculation of three-loop $\beta$-functions and anomalous dimensions poses special technical challenges, such as the huge number of diagrams and the proper treatment of $\gamma_5$ in dimensional regularization. In order to avoid infrared divergences resulting from setting external momenta to zero in the case of the Higgs self-coupling an auxiliary mass is used to compute the ultraviolet divergences needed for the renormalization constants. This method is explained in some detail. Finally, an update for the status of the vacuum stability problem in the Standard Model up to the Planck scale is presented.
[ { "created": "Thu, 24 Jul 2014 15:03:37 GMT", "version": "v1" } ]
2014-07-25
[ [ "Zoller", "Max F.", "" ] ]
In the last two years the renormalization group functions for the couplings and fields of the Standard Model have been computed at three-loop level. The evolution of the self-coupling $\lambda$ of the Standard Model Higgs boson is of particular importance due to its close connection with the stability of the Standard Model vacuum state. In this talk the three-loop corrections to the $\beta$-function for this crucial coupling are discussed. The calculation of three-loop $\beta$-functions and anomalous dimensions poses special technical challenges, such as the huge number of diagrams and the proper treatment of $\gamma_5$ in dimensional regularization. In order to avoid infrared divergences resulting from setting external momenta to zero in the case of the Higgs self-coupling an auxiliary mass is used to compute the ultraviolet divergences needed for the renormalization constants. This method is explained in some detail. Finally, an update for the status of the vacuum stability problem in the Standard Model up to the Planck scale is presented.
1808.02909
Vincent Cheung
Vincent Cheung, Ramona Vogt
Production and polarization of prompt $J/\psi$ in the improved color evaporation model using the $k_T$-factorization approach
null
Phys. Rev. D 98, 114029 (2018)
10.1103/PhysRevD.98.114029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the polarization of prompt $J/\psi$ production in the improved color evaporation model at leading order employing the $k_T$-factorization approach. In this paper, we present the polarization parameter $\lambda_\vartheta$ of prompt $J/\psi$ as a function of transverse momentum in $p+p$ and $p$ + A collisions to compare with data in the helicity, Collins-Soper and Gottfried-Jackson frames. We also present calculations of the charmonium production cross sections as a function of rapidity and transverse momentum. This is the first $p_T$-dependent calculation of charmonium polarization in the improved color evaporation model. We find agreement with both charmonium cross sections and polarization measurements.
[ { "created": "Wed, 8 Aug 2018 18:27:14 GMT", "version": "v1" } ]
2019-01-02
[ [ "Cheung", "Vincent", "" ], [ "Vogt", "Ramona", "" ] ]
We calculate the polarization of prompt $J/\psi$ production in the improved color evaporation model at leading order employing the $k_T$-factorization approach. In this paper, we present the polarization parameter $\lambda_\vartheta$ of prompt $J/\psi$ as a function of transverse momentum in $p+p$ and $p$ + A collisions to compare with data in the helicity, Collins-Soper and Gottfried-Jackson frames. We also present calculations of the charmonium production cross sections as a function of rapidity and transverse momentum. This is the first $p_T$-dependent calculation of charmonium polarization in the improved color evaporation model. We find agreement with both charmonium cross sections and polarization measurements.
1102.5009
John Ellis
John Ellis
Searching for Particle Physics Beyond the Standard Model at the LHC and Elsewhere
20 pages, 11 figures, talk presented at the 11th conference on "Frontiers of Fundamental Physics", Paris, July 2010
null
10.1063/1.4727987
CERN-PH-TH/2011-003, KCL-PH-TH/2011-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Following a general introduction to open questions beyond the Standard Model, the prospects for addressing them in the new era opened up by the LHC are reviewed. Sample highlights are given of ways in which the LHC is already probing beyond previous experiments, including the searches for supersymmetry, quark and gluon substructure and microscopic black holes.
[ { "created": "Thu, 24 Feb 2011 14:51:40 GMT", "version": "v1" } ]
2015-05-27
[ [ "Ellis", "John", "" ] ]
Following a general introduction to open questions beyond the Standard Model, the prospects for addressing them in the new era opened up by the LHC are reviewed. Sample highlights are given of ways in which the LHC is already probing beyond previous experiments, including the searches for supersymmetry, quark and gluon substructure and microscopic black holes.
hep-ph/9804457
Mayumi Aoki
Mayumi Aoki (Graduate School of Humanities and Sciences, Ochanomizu University), Noriyuki Oshimo (Institute for Cosmic Ray Research, University of Tokyo), Akio Sugamoto (Department of Physics, Ochanomizu University)
Baryon asymmetry and neutron EDM
5 pages, To be published in the Proceedings of the International Workshop on JHF Science (JHF98) held at KEK from March 3 to March 7
null
null
OCHA-PP-117
hep-ph
null
Baryon asymmetry of the universe can be generated by new sources of $CP$ violation intrinsic in supersymmetric extension of the standard model. This scenario predicts the neutron electric dipole moment to be not much smaller than its present experimental upper bound.
[ { "created": "Thu, 30 Apr 1998 08:48:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Aoki", "Mayumi", "", "Graduate School of Humanities and Sciences, Ochanomizu\n University" ], [ "Oshimo", "Noriyuki", "", "Institute for Cosmic Ray Research, University\n of Tokyo" ], [ "Sugamoto", "Akio", "", "Department of Physics, Ochanomizu University...
Baryon asymmetry of the universe can be generated by new sources of $CP$ violation intrinsic in supersymmetric extension of the standard model. This scenario predicts the neutron electric dipole moment to be not much smaller than its present experimental upper bound.
1411.2104
Hideaki Okane
Takuya Morozumi, Hideaki Okane, Hiroyuki Umeeda
Precise Discussion of Time-Reversal Asymmetries in B-meson decays
29pages, 5 figures. In version3, the title is changed. The difference between the event number asymmetry and the asymmetry measured by BaBar experiment is clarified
null
10.1007/JHEP02(2015)174
HUPD1404
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
BaBar collaboration announced that they observed time reversal (T) asymmetry through $B$ meson system. In the experiment, time dependencies of two distinctive processes, $B_- \rightarrow \bar{B^0}$ and $\bar{B^0}\rightarrow B_-$($-$ expresses CP value) are compared with each other. In our study, we examine event number difference of these two processes. In contrast to the BaBar asymmetry, the asymmetry of events number includes the overall normalization difference for rates. Time dependence of the asymmetry is more general and it includes terms absent in one used by BaBar collaboration. Both of the BaBar asymmetry and ours are naively thought to be T-odd since two processes compared are related with flipping time direction. We investigate the time reversal transformation property of our asymmetry. Using our notation, one can see that the asymmetry is not precisely a T-odd quantity, taking into account indirect CP and CPT violation of K meson systems. The effect of $\epsilon_K$ is extracted and gives rise to $\mathcal{O}(10^{-3})$ contribution. The introduced parameters are invariant under rephasing of quarks so that the coefficients of our asymmetry are expressed as phase convention independent quantities. Some combinations of the asymmetry enable us to extract parameters for wrong sign decays of $B_d$ meson, CPT violation, etc. We also study the reason why the T-even terms are allowed to contribute to the asymmetry, and find that several conditions are needed for the asymmetry to be a T-odd quantity.
[ { "created": "Sat, 8 Nov 2014 10:24:30 GMT", "version": "v1" }, { "created": "Fri, 12 Dec 2014 13:53:01 GMT", "version": "v2" }, { "created": "Wed, 14 Jan 2015 01:44:26 GMT", "version": "v3" } ]
2015-06-23
[ [ "Morozumi", "Takuya", "" ], [ "Okane", "Hideaki", "" ], [ "Umeeda", "Hiroyuki", "" ] ]
BaBar collaboration announced that they observed time reversal (T) asymmetry through $B$ meson system. In the experiment, time dependencies of two distinctive processes, $B_- \rightarrow \bar{B^0}$ and $\bar{B^0}\rightarrow B_-$($-$ expresses CP value) are compared with each other. In our study, we examine event number difference of these two processes. In contrast to the BaBar asymmetry, the asymmetry of events number includes the overall normalization difference for rates. Time dependence of the asymmetry is more general and it includes terms absent in one used by BaBar collaboration. Both of the BaBar asymmetry and ours are naively thought to be T-odd since two processes compared are related with flipping time direction. We investigate the time reversal transformation property of our asymmetry. Using our notation, one can see that the asymmetry is not precisely a T-odd quantity, taking into account indirect CP and CPT violation of K meson systems. The effect of $\epsilon_K$ is extracted and gives rise to $\mathcal{O}(10^{-3})$ contribution. The introduced parameters are invariant under rephasing of quarks so that the coefficients of our asymmetry are expressed as phase convention independent quantities. Some combinations of the asymmetry enable us to extract parameters for wrong sign decays of $B_d$ meson, CPT violation, etc. We also study the reason why the T-even terms are allowed to contribute to the asymmetry, and find that several conditions are needed for the asymmetry to be a T-odd quantity.
hep-ph/9408305
Rik Tangerman
R.D. Tangerman and P.J. Mulders
Polarized twist-three distributions $g_T$ and $h_L$ and the role of intrinsic transverse momentum
21 pages, REVTEX 3.0 (6 figures included in separate LATEX file using feynman.tex, others available upon request), NIKHEF-94-P7
null
null
null
hep-ph
null
In a nonstandard way we split up the polarized quark distributions $g_T$ and $h_L$ into their twist-two, quark-mass, and interaction-dependent parts, emphasizing the sensitivity to quark intrinsic transverse momentum. We show how to derive the Burkhardt-Cottingham sum rule in this approach and derive a similar sum rule for the chiral-odd distribution $h_2$. The effect of intrinsic transverse momentum in experimental observables is illustrated in the calculation of the ${\cal O}(1/Q)$ double-spin asymmetry $A_{LT}$ in Drell-Yan scattering.
[ { "created": "Tue, 16 Aug 1994 15:35:35 GMT", "version": "v1" } ]
2009-09-25
[ [ "Tangerman", "R. D.", "" ], [ "Mulders", "P. J.", "" ] ]
In a nonstandard way we split up the polarized quark distributions $g_T$ and $h_L$ into their twist-two, quark-mass, and interaction-dependent parts, emphasizing the sensitivity to quark intrinsic transverse momentum. We show how to derive the Burkhardt-Cottingham sum rule in this approach and derive a similar sum rule for the chiral-odd distribution $h_2$. The effect of intrinsic transverse momentum in experimental observables is illustrated in the calculation of the ${\cal O}(1/Q)$ double-spin asymmetry $A_{LT}$ in Drell-Yan scattering.
hep-ph/9911380
Mark Trodden
Marcelo Gleiser and Mark Trodden
Weakly First Order Cosmological Phase Transitions and Fermion Production
5 pages, 4 figures, RevTeX. Some extra clarifying discussion added. To appear in Phys. Lett. B
Phys.Lett. B517 (2001) 7-12
10.1016/S0370-2693(01)00974-1
CWRU-P34-99
hep-ph
null
We study weakly first order cosmological phase transitions in finite temperature field theories. Focusing on the standard electroweak theory and its minimal supersymmetric extension, we identify the regimes of Higgs masses for which the phase transition in these models proceeds by significant phase mixing and the coarsening of the subsequent domain network. This dynamics is distinct from that for strongly first order transitions, which proceed by the nucleation and propagation of critical bubbles. We describe how electroweak baryogenesis might take place in these models, explaining how our new picture can relax the sphaleron washout bound of traditional scenarios.
[ { "created": "Tue, 16 Nov 1999 16:15:51 GMT", "version": "v1" }, { "created": "Mon, 17 Sep 2001 18:09:07 GMT", "version": "v2" } ]
2009-10-31
[ [ "Gleiser", "Marcelo", "" ], [ "Trodden", "Mark", "" ] ]
We study weakly first order cosmological phase transitions in finite temperature field theories. Focusing on the standard electroweak theory and its minimal supersymmetric extension, we identify the regimes of Higgs masses for which the phase transition in these models proceeds by significant phase mixing and the coarsening of the subsequent domain network. This dynamics is distinct from that for strongly first order transitions, which proceed by the nucleation and propagation of critical bubbles. We describe how electroweak baryogenesis might take place in these models, explaining how our new picture can relax the sphaleron washout bound of traditional scenarios.
2004.03622
Stephan Narison
Stephan Narison (LUPM-CNRS-IN2P2, Montpellier)
Spectra and Decay Constants of $B_c$-like and $B^*_0$ Mesons in QCD
11 pages, 14 Figures, 3 Tables : Misprints corrected - Version to appear in Phys. Lett. B. arXiv admin note: text overlap with arXiv:1906.03614
null
10.1016/j.physletb.2020.135522
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the existing state of art of the QCD expressions of the two-point correlators into the Inverse Laplace sum rules (LSR) within stability criteria, we present a first analysis of the spectra and decay constants of B_c-like scalar (0^{++}) and axial-vector (1^{++}) mesons and revisit the ones of the B^*_c(1^{--}) vector meson. Improved predictions are obtained by combining these LSR results with the some mass-splittings from Heavy Quark Symmetry (HQS). We complete the analysis by revisiting the B^*_{0}(0^{++}) mass which might be likely identified with the B^*_J(5732) experimental candidate. The results for the spectra collected in Table 2 are compared with some recent lattice and potential models ones. New estimates of the decay constants are given in Table 3.
[ { "created": "Tue, 7 Apr 2020 18:01:21 GMT", "version": "v1" }, { "created": "Thu, 28 May 2020 09:56:52 GMT", "version": "v2" }, { "created": "Wed, 3 Jun 2020 15:39:12 GMT", "version": "v3" } ]
2023-08-08
[ [ "Narison", "Stephan", "", "LUPM-CNRS-IN2P2, Montpellier" ] ]
Using the existing state of art of the QCD expressions of the two-point correlators into the Inverse Laplace sum rules (LSR) within stability criteria, we present a first analysis of the spectra and decay constants of B_c-like scalar (0^{++}) and axial-vector (1^{++}) mesons and revisit the ones of the B^*_c(1^{--}) vector meson. Improved predictions are obtained by combining these LSR results with the some mass-splittings from Heavy Quark Symmetry (HQS). We complete the analysis by revisiting the B^*_{0}(0^{++}) mass which might be likely identified with the B^*_J(5732) experimental candidate. The results for the spectra collected in Table 2 are compared with some recent lattice and potential models ones. New estimates of the decay constants are given in Table 3.
1401.8124
Ilkka Helenius
Ilkka Helenius, Kari J. Eskola, Hannu Paukkunen
Centrality and rapidity dependence of inclusive pion and prompt photon production in p+Pb collisions at the LHC with EPS09s nPDFs
8 pages, 8 figures, Prepared for the Proceedings of "9th International Workshop on High-pT Physics at LHC", LPSC Grenoble, France, 24-28 September 2013
null
10.1088/1742-6596/589/1/012010
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The centrality dependencies of the inclusive neutral pion and prompt photon nuclear modification factors for p+Pb collisions at the LHC are studied using a spatially dependent set of nuclear PDFs, EPS09s. The calculations are performed at mid- and forward rapidities searching for an observable which would optimally probe the spatial dependence of the nuclear PDFs. In addition, we discuss to which $x$ values of the nucleus the different observables are sensitive.
[ { "created": "Fri, 31 Jan 2014 10:51:10 GMT", "version": "v1" } ]
2015-06-18
[ [ "Helenius", "Ilkka", "" ], [ "Eskola", "Kari J.", "" ], [ "Paukkunen", "Hannu", "" ] ]
The centrality dependencies of the inclusive neutral pion and prompt photon nuclear modification factors for p+Pb collisions at the LHC are studied using a spatially dependent set of nuclear PDFs, EPS09s. The calculations are performed at mid- and forward rapidities searching for an observable which would optimally probe the spatial dependence of the nuclear PDFs. In addition, we discuss to which $x$ values of the nucleus the different observables are sensitive.
1005.5022
Neda Sadooghi
Sh. Fayazbakhsh and N. Sadooghi
Color neutral 2SC phase of cold and dense quark matter in the presence of constant magnetic fields
33 pages, 9 Figures, 5 Tables; V2: Version accepted for publication in PRD
Phys.Rev.D82:045010,2010
10.1103/PhysRevD.82.045010
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The color neutral two-flavor superconducting (2SC) phase of cold and dense quark matter is studied in the presence of constant magnetic fields and at moderate baryon densities. In the first part of the paper, a two-flavor effective Nambu--Jona-Lasinio model consisting of a chiral symmetry breaking mass gap sigma_{B}, a color superconducting mass gap Delta_{B} and a color neutrality coefficient mu_{8} is introduced in the presence of a rotated U(1) magnetic field B. To study the phenomenon of magnetic catalysis in the presence of strong magnetic fields, the gap equations corresponding to sigma_{B} and Delta_{B}, as well as mu_{8} are solved in the lowest Landau level approximation. In the second part of the paper, a detailed numerical analysis is performed to explore the effect of any arbitrary magnetic field on the above mass gaps and the color neutrality coefficient. The structure of the chiral symmetry breaking and color superconducting phases is also presented in the mu_{c}-B plane, and the effect of the color neutrality coefficient mu_{8} on the phase structure of the model is explored. As it turns out, whereas the transition from the chiral symmetry breaking to color superconducting phase is of first order, nonvanishing mu_{8} affects essentially the second order phase transition from color superconducting to the normal phase.
[ { "created": "Thu, 27 May 2010 10:25:56 GMT", "version": "v1" }, { "created": "Tue, 13 Jul 2010 13:44:14 GMT", "version": "v2" } ]
2011-08-17
[ [ "Fayazbakhsh", "Sh.", "" ], [ "Sadooghi", "N.", "" ] ]
The color neutral two-flavor superconducting (2SC) phase of cold and dense quark matter is studied in the presence of constant magnetic fields and at moderate baryon densities. In the first part of the paper, a two-flavor effective Nambu--Jona-Lasinio model consisting of a chiral symmetry breaking mass gap sigma_{B}, a color superconducting mass gap Delta_{B} and a color neutrality coefficient mu_{8} is introduced in the presence of a rotated U(1) magnetic field B. To study the phenomenon of magnetic catalysis in the presence of strong magnetic fields, the gap equations corresponding to sigma_{B} and Delta_{B}, as well as mu_{8} are solved in the lowest Landau level approximation. In the second part of the paper, a detailed numerical analysis is performed to explore the effect of any arbitrary magnetic field on the above mass gaps and the color neutrality coefficient. The structure of the chiral symmetry breaking and color superconducting phases is also presented in the mu_{c}-B plane, and the effect of the color neutrality coefficient mu_{8} on the phase structure of the model is explored. As it turns out, whereas the transition from the chiral symmetry breaking to color superconducting phase is of first order, nonvanishing mu_{8} affects essentially the second order phase transition from color superconducting to the normal phase.
1712.02707
Amaresh Jaiswal
Amaresh Jaiswal, Partha Pratim Bhaduri
Effect of an anisotropic escape mechanism on elliptic flow in relativistic heavy-ion collisions
6 pages, 2 figures, published version
Phys. Rev. C 97, 044909 (2018)
10.1103/PhysRevC.97.044909
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effect of anisotropic escape mechanism on elliptic flow in relativistic heavy-ion collisions. We use Glauber model to generate initial conditions and ignore hydrodynamic expansion in the transverse direction. We employ Beer-Lambert law to allow for the transmittance of produced hadrons in the medium and calculate the anisotropy generated due to the suppression of particles traversing through the medium. In order to separate non-flow contribution due to surface bias effects, we ignore hydrodynamic expansion in the transverse direction and consider purely longitudinal boost-invariant expansion. We calculate the transverse momentum dependence of elliptic flow, generated from anisotropic escape mechanism due to surface bias effects, for various centralities in $\sqrt{s_{NN}}=200$ GeV Au$+$Au collisions at RHIC and $\sqrt{s_{NN}}=2.76$ TeV Pb$+$Pb collisions at LHC. We find that the surface bias effects have a sizable contribution to the total elliptic flow observed in heavy-ion collisions indicating that the viscosity of the QCD matter extracted from hydrodynamic simulations may be underestimated.
[ { "created": "Thu, 7 Dec 2017 16:44:01 GMT", "version": "v1" }, { "created": "Tue, 17 Apr 2018 03:58:07 GMT", "version": "v2" } ]
2018-04-18
[ [ "Jaiswal", "Amaresh", "" ], [ "Bhaduri", "Partha Pratim", "" ] ]
We study the effect of anisotropic escape mechanism on elliptic flow in relativistic heavy-ion collisions. We use Glauber model to generate initial conditions and ignore hydrodynamic expansion in the transverse direction. We employ Beer-Lambert law to allow for the transmittance of produced hadrons in the medium and calculate the anisotropy generated due to the suppression of particles traversing through the medium. In order to separate non-flow contribution due to surface bias effects, we ignore hydrodynamic expansion in the transverse direction and consider purely longitudinal boost-invariant expansion. We calculate the transverse momentum dependence of elliptic flow, generated from anisotropic escape mechanism due to surface bias effects, for various centralities in $\sqrt{s_{NN}}=200$ GeV Au$+$Au collisions at RHIC and $\sqrt{s_{NN}}=2.76$ TeV Pb$+$Pb collisions at LHC. We find that the surface bias effects have a sizable contribution to the total elliptic flow observed in heavy-ion collisions indicating that the viscosity of the QCD matter extracted from hydrodynamic simulations may be underestimated.
0910.4396
Atri Bhattacharya
Atri Bhattacharya, Sandhya Choubey, Raj Gandhi and Atsushi Watanabe
Diffuse Ultra-High Energy Neutrino Fluxes and Physics Beyond the Standard Model
v1: 5 pages, 3 figures v2: One new figure and related discussion added, references added v3: Published version. 7 pages, 5 figures
Phys.Lett.B690:42-47,2010
10.1016/j.physletb.2010.04.078
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study spectral distortions of diffuse ultra-high energy (UHE) neutrino flavour fluxes resulting due to physics beyond the Standard Model (SM). Even large spectral differences between flavours at the source are massaged into a common shape at earth by SM oscillations, thus, any significant observed spectral differences are an indicator of new physics present in the oscillation probability during propagation. Neutrino decay and Lorentz symmetry violation (LV) are examples, and result in significant distortion of the fluxes and the well-known bounds on them, which may allow UHE detectors to probe lifetimes, the mass hierarchy and LV parameters over a broad range.
[ { "created": "Fri, 23 Oct 2009 15:50:03 GMT", "version": "v1" }, { "created": "Wed, 3 Feb 2010 15:37:15 GMT", "version": "v2" }, { "created": "Thu, 10 Jun 2010 19:16:53 GMT", "version": "v3" } ]
2014-11-20
[ [ "Bhattacharya", "Atri", "" ], [ "Choubey", "Sandhya", "" ], [ "Gandhi", "Raj", "" ], [ "Watanabe", "Atsushi", "" ] ]
We study spectral distortions of diffuse ultra-high energy (UHE) neutrino flavour fluxes resulting due to physics beyond the Standard Model (SM). Even large spectral differences between flavours at the source are massaged into a common shape at earth by SM oscillations, thus, any significant observed spectral differences are an indicator of new physics present in the oscillation probability during propagation. Neutrino decay and Lorentz symmetry violation (LV) are examples, and result in significant distortion of the fluxes and the well-known bounds on them, which may allow UHE detectors to probe lifetimes, the mass hierarchy and LV parameters over a broad range.
hep-ph/0212182
Felipe J. Llanes-Estrada
Felipe J. Llanes-Estrada and Pedro Bicudo
Relativistic Quark Model Calculation of the l1, l2 Coefficients of the Chiral Lagrangian
Proc. V Intnal. Conf. on Quark Confinement and the Hadron Spectrum, Gargnano,Italy 2002
null
10.1142/9789812704269_0059
null
hep-ph
null
We briefly report on a relativistic quark model scheme to calculate the O(P^4) pion-pion vertex in the planar approximation and in the chiral limit. The calculation is reduced to the solution of simple integral equations (Bethe-Salpeter like) by an effective use of chiral Ward Identities. Specific model computations are provided.
[ { "created": "Fri, 13 Dec 2002 14:13:00 GMT", "version": "v1" } ]
2017-08-23
[ [ "Llanes-Estrada", "Felipe J.", "" ], [ "Bicudo", "Pedro", "" ] ]
We briefly report on a relativistic quark model scheme to calculate the O(P^4) pion-pion vertex in the planar approximation and in the chiral limit. The calculation is reduced to the solution of simple integral equations (Bethe-Salpeter like) by an effective use of chiral Ward Identities. Specific model computations are provided.
2211.00961
Abhishek Iyer M
G. Cacciapaglia, A. Deandrea, A.M. Iyer, A. Pinto
Sifting composite from elementary models at FCCee and CePC
7 Pages, 2 Figures
SciPost Phys. 14, 170 (2023)
10.21468/SciPostPhys.14.6.170
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
New Physics models with either an elementary or composite origin are often associated with a similar imprint in a direct search at colliders, case in point being the production of a light pseudoscalar in association with a monochromatic photon from the decay of a Z boson at future $e+e-$ colliders. We exploit the correlation between the discovery of a signal in the Z decays and electroweak precision measurements as a tool to distinguish a composite model from an elementary scalar one. Our results offer an appealing and rich physics case for future colliders and demonstrate how a lepton collider at the Z mass can be a discovery machine for new physics in the Higgs sector.
[ { "created": "Wed, 2 Nov 2022 08:58:21 GMT", "version": "v1" } ]
2023-06-22
[ [ "Cacciapaglia", "G.", "" ], [ "Deandrea", "A.", "" ], [ "Iyer", "A. M.", "" ], [ "Pinto", "A.", "" ] ]
New Physics models with either an elementary or composite origin are often associated with a similar imprint in a direct search at colliders, case in point being the production of a light pseudoscalar in association with a monochromatic photon from the decay of a Z boson at future $e+e-$ colliders. We exploit the correlation between the discovery of a signal in the Z decays and electroweak precision measurements as a tool to distinguish a composite model from an elementary scalar one. Our results offer an appealing and rich physics case for future colliders and demonstrate how a lepton collider at the Z mass can be a discovery machine for new physics in the Higgs sector.
hep-ph/0206053
Y. B. Bergner
Y. Bergner, Luis M. A. Bettencourt
A Step Beyond the Bounce: Bubble Dynamics in Quantum Phase Transitions
12 pages, multiple figures
Phys.Rev.D68:025014,2003
10.1103/PhysRevD.68.025014
MIT-CTP-3273
hep-ph cond-mat hep-lat hep-th nlin.PS
null
We study the dynamical evolution of a phase interface or bubble in the context of a \lambda \phi^4 + g \phi^6 scalar quantum field theory. We use a self-consistent mean-field approximation derived from a 2PI effective action to construct an initial value problem for the expectation value of the quantum field and two-point function. We solve the equations of motion numerically in (1+1)-dimensions and compare the results to the purely classical evolution. We find that the quantum fluctuations dress the classical profile, affecting both the early time expansion of the bubble and the behavior upon collision with a neighboring interface.
[ { "created": "Wed, 5 Jun 2002 15:47:21 GMT", "version": "v1" }, { "created": "Thu, 13 Jun 2002 21:59:55 GMT", "version": "v2" } ]
2014-11-17
[ [ "Bergner", "Y.", "" ], [ "Bettencourt", "Luis M. A.", "" ] ]
We study the dynamical evolution of a phase interface or bubble in the context of a \lambda \phi^4 + g \phi^6 scalar quantum field theory. We use a self-consistent mean-field approximation derived from a 2PI effective action to construct an initial value problem for the expectation value of the quantum field and two-point function. We solve the equations of motion numerically in (1+1)-dimensions and compare the results to the purely classical evolution. We find that the quantum fluctuations dress the classical profile, affecting both the early time expansion of the bubble and the behavior upon collision with a neighboring interface.
2312.05957
Yizhuang Liu
Yizhuang Liu
Causality constraints on TMD soft factors: the exponential regulator without cuts
24 pages, 3 figures. Typos related to L^-, L^+ in certain Wilson-lines are corrected and a new appendix B on path-connectedness of certain regions is added
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that as a result of causality-constrained coordinate space analyticity, the Drell-Yan-shape transverse-momentum dependent soft factor in the exponential regulator allows below-threshold (Euclidean) parametric representations without cuts, to all orders in perturbation theory. Moreover, it is identical to another soft factor with natural interpretation as a space-like form factor and this relation continues to hold for a larger class of TMD soft factors that interpolate between three different rapidity regulators: the off-light-cone regulator, the finite light-front length regulator and the exponential regulator.
[ { "created": "Sun, 10 Dec 2023 18:01:13 GMT", "version": "v1" }, { "created": "Tue, 12 Dec 2023 15:12:12 GMT", "version": "v2" }, { "created": "Mon, 18 Dec 2023 18:57:59 GMT", "version": "v3" }, { "created": "Tue, 2 Jan 2024 21:19:20 GMT", "version": "v4" }, { "cr...
2024-01-09
[ [ "Liu", "Yizhuang", "" ] ]
We show that as a result of causality-constrained coordinate space analyticity, the Drell-Yan-shape transverse-momentum dependent soft factor in the exponential regulator allows below-threshold (Euclidean) parametric representations without cuts, to all orders in perturbation theory. Moreover, it is identical to another soft factor with natural interpretation as a space-like form factor and this relation continues to hold for a larger class of TMD soft factors that interpolate between three different rapidity regulators: the off-light-cone regulator, the finite light-front length regulator and the exponential regulator.
2310.03631
Vedran Brdar
Fernando Arias-Arag\'on, Vedran Brdar, J\'er\'emie Quevillon
New Directions for ALP Searches Combining Nuclear Reactors and Haloscopes
7 pages, 4 figures
Phys. Rev. Lett. 132, 211802 (2024)
10.1103/PhysRevLett.132.211802
CERN-TH-2023-178
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we propose reactoscope, a novel experimental setup for axion-like particle (ALP) searches. Nuclear reactors produce a copious number of photons, a fraction of which could convert into ALPs via Primakoff process in the reactor core. The generated flux of ALPs leaves the nuclear power plant and its passage through a region with a strong magnetic field results in the efficient conversion to photons which can be detected. Such magnetic field is the key component of axion haloscope experiments. Adjacent nuclear reactor and axion haloscope experiment exist in Grenoble, France. There, the Institut Laue-Langevin (ILL) research reactor is situated only $\sim 700$ m from GrAHal, the axion haloscope platform designed to offer several volume and magnetic field (up to 43 T) configurations. We derive sensitivity projections for photophilic ALP searches with ILL and GrAHal, and also scrutinize analogous realizations, such as the one comprising of CAST experiment at CERN and Bugey nuclear power plant. The results that we obtain complement and extend the reach of existing laboratory experiments, e.g. light-shining-through-walls. While the derived sensitivities are not competitive when compared to the astrophysical limits, our analysis is free from the assumptions associated to those.
[ { "created": "Thu, 5 Oct 2023 16:05:02 GMT", "version": "v1" }, { "created": "Thu, 23 May 2024 08:13:04 GMT", "version": "v2" } ]
2024-05-24
[ [ "Arias-Aragón", "Fernando", "" ], [ "Brdar", "Vedran", "" ], [ "Quevillon", "Jérémie", "" ] ]
In this work we propose reactoscope, a novel experimental setup for axion-like particle (ALP) searches. Nuclear reactors produce a copious number of photons, a fraction of which could convert into ALPs via Primakoff process in the reactor core. The generated flux of ALPs leaves the nuclear power plant and its passage through a region with a strong magnetic field results in the efficient conversion to photons which can be detected. Such magnetic field is the key component of axion haloscope experiments. Adjacent nuclear reactor and axion haloscope experiment exist in Grenoble, France. There, the Institut Laue-Langevin (ILL) research reactor is situated only $\sim 700$ m from GrAHal, the axion haloscope platform designed to offer several volume and magnetic field (up to 43 T) configurations. We derive sensitivity projections for photophilic ALP searches with ILL and GrAHal, and also scrutinize analogous realizations, such as the one comprising of CAST experiment at CERN and Bugey nuclear power plant. The results that we obtain complement and extend the reach of existing laboratory experiments, e.g. light-shining-through-walls. While the derived sensitivities are not competitive when compared to the astrophysical limits, our analysis is free from the assumptions associated to those.
2406.00957
Xiaoyun Chen
Xiaoyun Chen, Yue Tan
The light quarkonium and charmonium mass shifts in an unquenched quark model
11 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The unquenched quark model for the light quarkonium and the charmonium states is explored in the present work. The quark-pair creation operator in the $^3P_0$ model, which mix the two-quark and four-quark components is modified by considering the effects of the created quark pair's energy, as well as the separation between the created quark pair and the valence quark pair. All the wave functions needed including the mesons and the relative motion between two mesons are all obtained by solving the corresponding Schr\"{o}dinger equation with the help of the Gaussian expansion method. Our aim of the present work is to find a new set of parameters which can give a good description of the mass spectrum of the low-lying light quarkonium and charmonium states. Moreover, some exotic states, for example $X(3872)$ can be described well in the unquenched quark model.
[ { "created": "Mon, 3 Jun 2024 03:16:47 GMT", "version": "v1" } ]
2024-06-04
[ [ "Chen", "Xiaoyun", "" ], [ "Tan", "Yue", "" ] ]
The unquenched quark model for the light quarkonium and the charmonium states is explored in the present work. The quark-pair creation operator in the $^3P_0$ model, which mix the two-quark and four-quark components is modified by considering the effects of the created quark pair's energy, as well as the separation between the created quark pair and the valence quark pair. All the wave functions needed including the mesons and the relative motion between two mesons are all obtained by solving the corresponding Schr\"{o}dinger equation with the help of the Gaussian expansion method. Our aim of the present work is to find a new set of parameters which can give a good description of the mass spectrum of the low-lying light quarkonium and charmonium states. Moreover, some exotic states, for example $X(3872)$ can be described well in the unquenched quark model.
hep-ph/9212307
null
John F. Donoghue and Jusak Tandean
The Equivalence Theorem and Global Anomalies
8 pages, LaTeX, figure available upon request, UMHEP-381
Phys.Lett. B301 (1993) 372-375
10.1016/0370-2693(93)91165-J
null
hep-ph
null
In the presence of some forms of global anomalies, the equivalence theorem, which relates the interactions of longitudinal gauge bosons to those of the Goldstone bosons, is not always valid. This can occur when the Goldstone sector contains an anomaly which is canceled in the gauge currents by the effects of a different sector of the theory. The example of the Standard Model without Higgs particles is used to illustrate this phenomena.
[ { "created": "Wed, 23 Dec 1992 18:43:44 GMT", "version": "v1" } ]
2009-10-22
[ [ "Donoghue", "John F.", "" ], [ "Tandean", "Jusak", "" ] ]
In the presence of some forms of global anomalies, the equivalence theorem, which relates the interactions of longitudinal gauge bosons to those of the Goldstone bosons, is not always valid. This can occur when the Goldstone sector contains an anomaly which is canceled in the gauge currents by the effects of a different sector of the theory. The example of the Standard Model without Higgs particles is used to illustrate this phenomena.
hep-ph/0412115
Makiko Nagashima
George Wei-Shu Hou
B-> phi K^(*) CPV/Polarization, and Collider Implications
4 pages, 4 figures. Presented at 32nd International Conference on High-Energy Physics (ICHEP 04), Beijing, China, 16-22 Aug 2004
null
null
null
hep-ph
null
The hint for BSM CP violation in B-> phi K_S is now more confused, but the phi K^* polarization anomaly seems real. We present a picture based on a flavor-mixed, right-handed "strange-beauty" squark \widetilde{sb}_{1R}, driven light by the large \tilde s_R-\tilde b_R squark flavor mixing, which carries a unique new CP phase. The \widetilde{sb}_{1R} could impact on S_{phi K_S} (or alternatively S_{eta^\prime K_S}), B_s mixing, \sin2Phi_{B_s}, S_{K_S\pi^0\gamma} and other b-> s transitions, and can be searched for directly at the Tevatron. Whether SM or BSM, a heuristic model is given where transverse phi K^* polarization descends from the gluon helicity of on-shell b-> sg.
[ { "created": "Wed, 8 Dec 2004 12:48:36 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hou", "George Wei-Shu", "" ] ]
The hint for BSM CP violation in B-> phi K_S is now more confused, but the phi K^* polarization anomaly seems real. We present a picture based on a flavor-mixed, right-handed "strange-beauty" squark \widetilde{sb}_{1R}, driven light by the large \tilde s_R-\tilde b_R squark flavor mixing, which carries a unique new CP phase. The \widetilde{sb}_{1R} could impact on S_{phi K_S} (or alternatively S_{eta^\prime K_S}), B_s mixing, \sin2Phi_{B_s}, S_{K_S\pi^0\gamma} and other b-> s transitions, and can be searched for directly at the Tevatron. Whether SM or BSM, a heuristic model is given where transverse phi K^* polarization descends from the gluon helicity of on-shell b-> sg.
1611.06919
Joao Pacheco B. C. de Melo Dr.
J. P. B. C. de Melo, K. Tsushima (Laboratorio de F{\i}sica Te\'orica e Computacional - LFTC, Universidade Cruzeiro do Sul)
In-medium rho-meson properties in a light-front approach
8 Pages, 6 eps figures. Proceedings of Light-Cone 2016, Lisbon Portugal
null
10.1007/s00601-017-1233-2
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Properties of \r{ho}-meson in symmetric nuclear matter are investigated within a light-front constituent quark model (LFCQM), using the in-medium input calculated by the quark-meson coupling (QMC) model. The LFCQM used here was previously applied in vacuum to calculate the \r{ho}-meson electromagnetic properties, namely, charge G 0 , magnetic G 1 , and quadrupole G 2 form factors, as well as the electromagnetic radius and decay constant. We predict the in-medium modifications of the \r{ho}-meson electromagnetic form factors in symmetric nuclear matter.
[ { "created": "Mon, 21 Nov 2016 17:49:04 GMT", "version": "v1" } ]
2017-03-08
[ [ "de Melo", "J. P. B. C.", "", "Laboratorio de Fısica Teórica e\n Computacional - LFTC, Universidade Cruzeiro do Sul" ], [ "Tsushima", "K.", "", "Laboratorio de Fısica Teórica e\n Computacional - LFTC, Universidade Cruzeiro do Sul" ] ]
Properties of \r{ho}-meson in symmetric nuclear matter are investigated within a light-front constituent quark model (LFCQM), using the in-medium input calculated by the quark-meson coupling (QMC) model. The LFCQM used here was previously applied in vacuum to calculate the \r{ho}-meson electromagnetic properties, namely, charge G 0 , magnetic G 1 , and quadrupole G 2 form factors, as well as the electromagnetic radius and decay constant. We predict the in-medium modifications of the \r{ho}-meson electromagnetic form factors in symmetric nuclear matter.
hep-ph/0112040
Xin-Heng Guo
X.-H. Guo and A.W. Thomas
Chiral extrapolation of lattice data for the hyperfine splittings of heavy mesons
27 pages, 6 figures
Phys.Rev.D65:074019,2002
10.1103/PhysRevD.65.074019
ADP-01-53/T485
hep-ph
null
Hyperfine splittings between the heavy vector (D*, B*) and pseudoscalar (D, B) mesons have been calculated numerically in lattice QCD, where the pion mass (which is related to the light quark mass) is much larger than its physical value. Naive linear chiral extrapolations of the lattice data to the physical mass of the pion lead to hyperfine splittings which are smaller than experimental data. In order to extrapolate these lattice data to the physical mass of the pion more reasonably, we apply the effective chiral perturbation theory for heavy mesons, which is invariant under chiral symmetry when the light quark masses go to zero and heavy quark symmetry when the heavy quark masses go to infinity. This leads to a phenomenological functional form with three parameters to extrapolate the lattice data. It is found that the extrapolated hyperfine splittings are even smaller than those obtained using linear extrapolation. We conclude that the source of the discrepancy between lattice data for hyperfine splittings and experiment must lie in non-chiral physics.
[ { "created": "Tue, 4 Dec 2001 05:58:15 GMT", "version": "v1" } ]
2010-02-17
[ [ "Guo", "X. -H.", "" ], [ "Thomas", "A. W.", "" ] ]
Hyperfine splittings between the heavy vector (D*, B*) and pseudoscalar (D, B) mesons have been calculated numerically in lattice QCD, where the pion mass (which is related to the light quark mass) is much larger than its physical value. Naive linear chiral extrapolations of the lattice data to the physical mass of the pion lead to hyperfine splittings which are smaller than experimental data. In order to extrapolate these lattice data to the physical mass of the pion more reasonably, we apply the effective chiral perturbation theory for heavy mesons, which is invariant under chiral symmetry when the light quark masses go to zero and heavy quark symmetry when the heavy quark masses go to infinity. This leads to a phenomenological functional form with three parameters to extrapolate the lattice data. It is found that the extrapolated hyperfine splittings are even smaller than those obtained using linear extrapolation. We conclude that the source of the discrepancy between lattice data for hyperfine splittings and experiment must lie in non-chiral physics.
1606.09268
Hubert Spiesberger
R. Bucoveanu, M. Gorchtein, H. Spiesberger
Precision Measurement of sin2(theta_w) at MESA
null
null
null
MITP/16-064
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A forthcoming experiment of low-energy elastic electron proton scattering at the new MESA facility in Mainz is planned to provide a high-precision measurement of the parity-violating polarisation asymmetry. This experiment is expected to lead to a precision determination of the weak mixing angle, competitive with Z-pole data. We discuss the challenges for theory to derive predictions with the required accuracy.
[ { "created": "Wed, 29 Jun 2016 20:19:43 GMT", "version": "v1" } ]
2016-07-01
[ [ "Bucoveanu", "R.", "" ], [ "Gorchtein", "M.", "" ], [ "Spiesberger", "H.", "" ] ]
A forthcoming experiment of low-energy elastic electron proton scattering at the new MESA facility in Mainz is planned to provide a high-precision measurement of the parity-violating polarisation asymmetry. This experiment is expected to lead to a precision determination of the weak mixing angle, competitive with Z-pole data. We discuss the challenges for theory to derive predictions with the required accuracy.
0904.1695
Yuki Adachi
Yuki Adachi, C. S. Lim and Nobuhito Maru
Lower Bound for Compactification Scale from Muon g - 2 in the Gauge-Higgs Unification
42 pages, 22 ps files, We reanalyzed muon g-2 in the ten dimensional representation
Nucl.Phys.B839:52-95,2010
10.1016/j.nuclphysb.2010.06.001
KOBE-TH-09-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a muon anomalous magnetic moment in a five dimensional SU (3) gauge- Higgs unification compactified on M^4 \times S^1 /Z_2 space-time including Z_2 -odd bulk mass for a fermion. We calculate one-loop corrections to the anomalous magnetic moment of muon and find a lower bound for the compactification scale to be around 5 \sim 6 TeV by comparing nonzero Kaluza-Klein mode contributions with the muon (g - 2) experiment at BNL.
[ { "created": "Fri, 10 Apr 2009 14:40:30 GMT", "version": "v1" }, { "created": "Tue, 9 Feb 2010 11:02:03 GMT", "version": "v2" }, { "created": "Thu, 3 Jun 2010 05:46:21 GMT", "version": "v3" } ]
2014-11-18
[ [ "Adachi", "Yuki", "" ], [ "Lim", "C. S.", "" ], [ "Maru", "Nobuhito", "" ] ]
We discuss a muon anomalous magnetic moment in a five dimensional SU (3) gauge- Higgs unification compactified on M^4 \times S^1 /Z_2 space-time including Z_2 -odd bulk mass for a fermion. We calculate one-loop corrections to the anomalous magnetic moment of muon and find a lower bound for the compactification scale to be around 5 \sim 6 TeV by comparing nonzero Kaluza-Klein mode contributions with the muon (g - 2) experiment at BNL.
hep-ph/0008086
Roberto Ugoccioni
J. Dias de Deus and R. Ugoccioni (CENTRA/IST, Lisboa)
Particle Densities in Heavy Ion Collisions at High Energy and the Dual String Model
6 pages, 2 figures, latex; corrected HIJING and added WA98 in fig.1; references added/updated; to appear in PLB
Phys.Lett. B491 (2000) 253-256
10.1016/S0370-2693(00)01055-8
FISIST/11-2000/CENTRA
hep-ph
null
We analyse recent results on charged particle pseudo-rapidity densities from RHIC in the framework of the Dual String Model, in particular when including string fusion. The model, in a simple way, agrees with all the existing data and is consistent with the presence of the percolation transition to the Quark-Gluon Plasma already at the CERN-SPS.
[ { "created": "Wed, 9 Aug 2000 18:20:03 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2000 13:28:52 GMT", "version": "v2" } ]
2009-10-31
[ [ "de Deus", "J. Dias", "", "CENTRA/IST, Lisboa" ], [ "Ugoccioni", "R.", "", "CENTRA/IST, Lisboa" ] ]
We analyse recent results on charged particle pseudo-rapidity densities from RHIC in the framework of the Dual String Model, in particular when including string fusion. The model, in a simple way, agrees with all the existing data and is consistent with the presence of the percolation transition to the Quark-Gluon Plasma already at the CERN-SPS.
1212.1636
Jay Tasson
Jay D. Tasson
Antimatter, the SME, and Gravity
10 pages, presented at the 10th International Conference on Low Energy Antiproton Physics (LEAP 2011), Vancouver, Canada, April 2011
Hyperfine Interact. 213, 137 (2012)
10.1007/s10751-012-0642-3
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number of SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.
[ { "created": "Fri, 7 Dec 2012 15:53:36 GMT", "version": "v1" } ]
2012-12-10
[ [ "Tasson", "Jay D.", "" ] ]
A general field-theoretic framework for the analysis of CPT and Lorentz violation is provided by the Standard-Model Extension (SME). This work discusses a number of SME-based proposals for tests of CPT and Lorentz symmetry, including antihydrogen spectroscopy and antimatter gravity tests.
1805.09239
Juri Fiaschi
Elena Accomando, Juri Fiaschi, Francesco Hautmann, Stefano Moretti
Neutral Current Forward-Backward Asymmetry: from $\theta_W$ to PDF Determinations
9 pages, 6 figures
Eur. Phys. J. C (2018) 78: 663
10.1140/epjc/s10052-018-6120-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measurements of the forward-backward asymmetry in neutral-current Drell-Yan di-lepton production have primarily been used for determinations of the weak mixing angle $\theta_W$. We observe that, unlike the case of Run-I of the Large Hadron Collider (LHC Run-I), for the first time at the LHC Run-II the reconstructed forward-backward asymmetry has the capability of placing useful constraints on the determination of the parton distribution functions (PDFs). By examining the statistical and the PDF uncertainties on the reconstructed forward-backward asymmetry, we investigate its potential for disentangling the flavour content of quark and antiquark PDFs. Access to the valence/sea $u$-quark and to the sea up-type antiquark PDFs, in particular, may be gained by the appropriate use of selection cuts in the rapidity of the emerging lepton pair in regions both near the $Z$-boson peak and away from it, in a manner complementary, though more indirect, to the case of the charged-current asymmetry. We study the extension of these results for the planned high-luminosity (HL) LHC.
[ { "created": "Wed, 23 May 2018 15:54:22 GMT", "version": "v1" }, { "created": "Sun, 19 Aug 2018 13:01:16 GMT", "version": "v2" }, { "created": "Mon, 18 Mar 2019 15:22:43 GMT", "version": "v3" } ]
2019-03-19
[ [ "Accomando", "Elena", "" ], [ "Fiaschi", "Juri", "" ], [ "Hautmann", "Francesco", "" ], [ "Moretti", "Stefano", "" ] ]
Measurements of the forward-backward asymmetry in neutral-current Drell-Yan di-lepton production have primarily been used for determinations of the weak mixing angle $\theta_W$. We observe that, unlike the case of Run-I of the Large Hadron Collider (LHC Run-I), for the first time at the LHC Run-II the reconstructed forward-backward asymmetry has the capability of placing useful constraints on the determination of the parton distribution functions (PDFs). By examining the statistical and the PDF uncertainties on the reconstructed forward-backward asymmetry, we investigate its potential for disentangling the flavour content of quark and antiquark PDFs. Access to the valence/sea $u$-quark and to the sea up-type antiquark PDFs, in particular, may be gained by the appropriate use of selection cuts in the rapidity of the emerging lepton pair in regions both near the $Z$-boson peak and away from it, in a manner complementary, though more indirect, to the case of the charged-current asymmetry. We study the extension of these results for the planned high-luminosity (HL) LHC.
2308.03070
Jiaxuan Luo
Jiaxuan. Luo, Xinbai. Li, Zebo. Tang, Xin. Wu, Wangmei. Zha
The effect of initial nuclear deformation on dielectron photoproduction in hadronic heavy-ion collisions
8 pages, 5 figures, 4 tables
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Significant excesses of $e^+e^-$ pair production at very low transverse momentum ($p_T <$ 0.15 GeV/c) were observed by the STAR collaboration in hadronic heavy-ion collisions. Such enhancement is assumed to be a sign of photon-photon production in heavy-ion collisions with hadronic overlap, based on comparisons with model calculations for spherical Au + Au collisions. However, there is a lack of calculations for $e^+e^-$ pair production from coherent photon-photon interactions in hadronic U + U collisions, due to the deformity of Uranium nuclei. In this article, we present calculations for $e^+e^-$ pair photoproduction at $\sqrt{s_{NN}}$ = 193 GeV in both spherical and deformed U + U collisions within STAR detector acceptance using the equivalent photon approximation (EPA). We conduct event-by-event analysis to investigate the effects of initial nuclear deformation on pair production. Our numerical results show good agreement with experimental data for the 40%--60% and 60%--80% centrality classes in U + U collisions, and the differences between spherical and deformed configurations are approximately 3\%. We also calculate the yields of the photoproduced $e^+e^-$ pair in hadronic deformed Ru + Ru and Zr + Zr collisions at $\sqrt{s_{NN}}$ = 200 GeV. The results reveal that the ratios of the yields of Ru to Zr exhibit very small differences ($<$ 1%) between spherical and deformed cases.
[ { "created": "Sun, 6 Aug 2023 09:42:29 GMT", "version": "v1" } ]
2023-08-08
[ [ "Luo", "Jiaxuan.", "" ], [ "Li", "Xinbai.", "" ], [ "Tang", "Zebo.", "" ], [ "Wu", "Xin.", "" ], [ "Zha", "Wangmei.", "" ] ]
Significant excesses of $e^+e^-$ pair production at very low transverse momentum ($p_T <$ 0.15 GeV/c) were observed by the STAR collaboration in hadronic heavy-ion collisions. Such enhancement is assumed to be a sign of photon-photon production in heavy-ion collisions with hadronic overlap, based on comparisons with model calculations for spherical Au + Au collisions. However, there is a lack of calculations for $e^+e^-$ pair production from coherent photon-photon interactions in hadronic U + U collisions, due to the deformity of Uranium nuclei. In this article, we present calculations for $e^+e^-$ pair photoproduction at $\sqrt{s_{NN}}$ = 193 GeV in both spherical and deformed U + U collisions within STAR detector acceptance using the equivalent photon approximation (EPA). We conduct event-by-event analysis to investigate the effects of initial nuclear deformation on pair production. Our numerical results show good agreement with experimental data for the 40%--60% and 60%--80% centrality classes in U + U collisions, and the differences between spherical and deformed configurations are approximately 3\%. We also calculate the yields of the photoproduced $e^+e^-$ pair in hadronic deformed Ru + Ru and Zr + Zr collisions at $\sqrt{s_{NN}}$ = 200 GeV. The results reveal that the ratios of the yields of Ru to Zr exhibit very small differences ($<$ 1%) between spherical and deformed cases.
hep-ph/9308206
null
Vittorio Del Duca
Parton-Parton Elastic Scattering and Rapidity Gaps at SSC and LHC Energies
7 pages
null
null
null
hep-ph
null
The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at SSC and LHC energies.
[ { "created": "Mon, 2 Aug 1993 20:37:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Del Duca", "Vittorio", "" ] ]
The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at SSC and LHC energies.
hep-ph/0510197
Andrea Romanino
G.F. Giudice and A. Romanino
Electric Dipole Moments in Split Supersymmetry
null
Phys.Lett. B634 (2006) 307-314
10.1016/j.physletb.2006.01.027
null
hep-ph
null
We perform a quantitative study of the neutron and electron electric dipole moments (EDM) in Supersymmetry, in the limit of heavy scalars. The leading contributions arise at two loops. We give the complete analytic result, including a new contribution associated with Z-Higgs exchange, which plays an important and often leading role in the neutron EDM. The predictions for the EDM are typically within the sensitivities of the next generation experiments. We also analyse the correlation between the electron and neutron EDM, which provides a robust test of Split Supersymmetry.
[ { "created": "Fri, 14 Oct 2005 18:31:48 GMT", "version": "v1" } ]
2009-11-11
[ [ "Giudice", "G. F.", "" ], [ "Romanino", "A.", "" ] ]
We perform a quantitative study of the neutron and electron electric dipole moments (EDM) in Supersymmetry, in the limit of heavy scalars. The leading contributions arise at two loops. We give the complete analytic result, including a new contribution associated with Z-Higgs exchange, which plays an important and often leading role in the neutron EDM. The predictions for the EDM are typically within the sensitivities of the next generation experiments. We also analyse the correlation between the electron and neutron EDM, which provides a robust test of Split Supersymmetry.
1306.2964
Stephon Alexander
Stephon H.S. Alexander
The Sterile Neutrino Field and Late Time Acceleration
4 pages, 1 figure
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that when the neutrino minimal standard model ($\nu MSM$) with a light sterile neutrino has a long range interaction between the neutrino vacuum charge density and a dark U(1) gauge potential, late time acceleration is dynamically realized. Moreover, the relation between the scale of dark energy, the weak and Planck masses derived by Arkani-Hamed et. al \cite{ArkaniHamed:2000tc} that addresses the coincidence problem arises naturally in this model. Assuming that the cosmological constant is zero by some as yet known mechanism, the only fine tuning in our model is the mass of the sterile neutrino. We show that perturbations of the vector fields are oscillatory and hence, there are no instabilities.
[ { "created": "Wed, 12 Jun 2013 20:12:15 GMT", "version": "v1" } ]
2013-06-14
[ [ "Alexander", "Stephon H. S.", "" ] ]
We show that when the neutrino minimal standard model ($\nu MSM$) with a light sterile neutrino has a long range interaction between the neutrino vacuum charge density and a dark U(1) gauge potential, late time acceleration is dynamically realized. Moreover, the relation between the scale of dark energy, the weak and Planck masses derived by Arkani-Hamed et. al \cite{ArkaniHamed:2000tc} that addresses the coincidence problem arises naturally in this model. Assuming that the cosmological constant is zero by some as yet known mechanism, the only fine tuning in our model is the mass of the sterile neutrino. We show that perturbations of the vector fields are oscillatory and hence, there are no instabilities.
hep-ph/9706268
null
Markus A. Luty and Eduardo Ponton
Effective Lagrangians and Light Gravitino Phenomenology
15 pages, LaTeX2e, 1 eps figure. Removed erroneous claim of coupling of photon to gravitino to photons at order M^2 E^2 / F^2. Strongest bound is from invisible Z width, giving F > (140 GeV)^2
Phys.Rev. D57 (1998) 4167-4173
10.1103/PhysRevD.57.4167
UMD-PP-97-116
hep-ph
null
We construct the low-energy effective lagrangian for a light gravitino coupled to the minimal supersymmetric standard model under the assumption that supersymmetry breaking is communicated to the observable sector dominantly through soft terms. Our effective lagrangian is written in terms of the spin-1/2 Goldstino (the longitudinal component of the gravitino) transforming under a non-linear realization of supersymmetry. In this lagrangian, the Goldstino is derivatively coupled and all couplings of the Goldstino to light fields are determined uniquely by the supersymmetry-breaking scale \sqrt{F}. This lagrangian is therefore a useful starting point for further investigation of the light gravitino in gauge-mediated supersymmetry breaking models. We show that the invisible width of the Z into Goldstinos gives the constraint \sqrt{F} > 140 GeV.
[ { "created": "Thu, 5 Jun 1997 20:17:26 GMT", "version": "v1" }, { "created": "Wed, 10 Sep 1997 20:51:56 GMT", "version": "v2" }, { "created": "Thu, 18 Dec 1997 22:06:30 GMT", "version": "v3" } ]
2009-10-30
[ [ "Luty", "Markus A.", "" ], [ "Ponton", "Eduardo", "" ] ]
We construct the low-energy effective lagrangian for a light gravitino coupled to the minimal supersymmetric standard model under the assumption that supersymmetry breaking is communicated to the observable sector dominantly through soft terms. Our effective lagrangian is written in terms of the spin-1/2 Goldstino (the longitudinal component of the gravitino) transforming under a non-linear realization of supersymmetry. In this lagrangian, the Goldstino is derivatively coupled and all couplings of the Goldstino to light fields are determined uniquely by the supersymmetry-breaking scale \sqrt{F}. This lagrangian is therefore a useful starting point for further investigation of the light gravitino in gauge-mediated supersymmetry breaking models. We show that the invisible width of the Z into Goldstinos gives the constraint \sqrt{F} > 140 GeV.
hep-ph/0311215
Ernest Ma
Ernest Ma
The Neutrino Mass Matrix - From A_4 to Z_3
15 pages, no figure, talk at 9th Adriatic Meeting, Dubrovnik (September 2003)
SpringerProc.Phys.98:3-13,2005
null
UCRHEP-T366
hep-ph
null
With the recent experimental advance in our precise knowledge of the neutrino oscillation parameters, the correct form of the 3 X 3 neutrino mass matrix is now approximately known. I discuss how this may be obtained from symmetry principles, using as examples the finite groups A_4 and Z_3, in two complete theories of leptons (and quarks).
[ { "created": "Mon, 17 Nov 2003 18:25:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ma", "Ernest", "" ] ]
With the recent experimental advance in our precise knowledge of the neutrino oscillation parameters, the correct form of the 3 X 3 neutrino mass matrix is now approximately known. I discuss how this may be obtained from symmetry principles, using as examples the finite groups A_4 and Z_3, in two complete theories of leptons (and quarks).
1112.6402
Marcelo Loewe
M. Loewe, F. Marquez, R. Zamora
The cylindrical \delta-potential and the Dirac equation
11 pages, 2 figures
J. Phys. A: Math. Theor. 45 (2012) 465303
10.1088/1751-8113/45/46/465303
null
hep-ph quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we discuss the Dirac equation in the presence of an attractive cylindrical \delta-shell potential V(\rho)=-a\delta(\rho-\rho_0), where \rho is the radial coordinate and a>0. We present a detailed discussion on the boundary conditions the wave function has to satisfy when crossing the support of the potential, proceeding then to explore the dependence of the ground state on the parameter a, analyzing the occurrence of supercritical effects. We also apply the Foldy-Wouthuysen transformation, discussing the non-relativistic limit of this problem.
[ { "created": "Thu, 29 Dec 2011 20:05:50 GMT", "version": "v1" }, { "created": "Tue, 9 Oct 2012 21:20:59 GMT", "version": "v2" }, { "created": "Sun, 4 Nov 2012 01:02:17 GMT", "version": "v3" } ]
2012-11-06
[ [ "Loewe", "M.", "" ], [ "Marquez", "F.", "" ], [ "Zamora", "R.", "" ] ]
In this article we discuss the Dirac equation in the presence of an attractive cylindrical \delta-shell potential V(\rho)=-a\delta(\rho-\rho_0), where \rho is the radial coordinate and a>0. We present a detailed discussion on the boundary conditions the wave function has to satisfy when crossing the support of the potential, proceeding then to explore the dependence of the ground state on the parameter a, analyzing the occurrence of supercritical effects. We also apply the Foldy-Wouthuysen transformation, discussing the non-relativistic limit of this problem.
hep-ph/9910283
Georg Weiglein
S. Heinemeyer, W. Hollik and G. Weiglein
Precise Calculations for the Neutral Higgs-Boson Masses in the MSSM
5 pages, 1 figure, to appear in the proceedings of the International Workshop on Linear Colliders, Sitges, April 28 - May 5, 1999
null
null
DESY 99-148, KA-TP-16-1999
hep-ph
null
We review the comparison of the results for the neutral CP-even Higgs-boson masses recently obtained within the Feynman-diagrammatic approach with the previous results based on the renormalization group approach. We show that the results differ by new genuine two-loop contributions present in the Feynman-diagrammatic calculation. The numerical effect of these terms on the result for m_h is briefly discussed.
[ { "created": "Fri, 8 Oct 1999 14:51:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Heinemeyer", "S.", "" ], [ "Hollik", "W.", "" ], [ "Weiglein", "G.", "" ] ]
We review the comparison of the results for the neutral CP-even Higgs-boson masses recently obtained within the Feynman-diagrammatic approach with the previous results based on the renormalization group approach. We show that the results differ by new genuine two-loop contributions present in the Feynman-diagrammatic calculation. The numerical effect of these terms on the result for m_h is briefly discussed.
2009.00640
Martin Beneke
Martin Beneke, Robert Szafron, Kai Urban
Sommerfeld-corrected relic abundance of wino dark matter with NLO electroweak potentials
48 pages, LaTeX
null
10.1007/JHEP02(2021)020
TUM-HEP-1281/20, CERN-TH-2020-144
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extending previous work, we calculate the electroweak potentials for all co-annihilation channels of wino dark matter at the one-loop order and obtain the wino relic abundance including the Sommerfeld effect at the next-to-leading order (NLO).
[ { "created": "Tue, 1 Sep 2020 18:09:21 GMT", "version": "v1" } ]
2021-02-24
[ [ "Beneke", "Martin", "" ], [ "Szafron", "Robert", "" ], [ "Urban", "Kai", "" ] ]
Extending previous work, we calculate the electroweak potentials for all co-annihilation channels of wino dark matter at the one-loop order and obtain the wino relic abundance including the Sommerfeld effect at the next-to-leading order (NLO).
hep-ph/9812361
Rathin Adhikari
R. Adhikari, G. Rajasekaran (Matscience, Chennai)
Constraints on mixing angles of Majorana neutrinos
Some corrections and clarifications added
Phys.Rev.D61:031301,2000
10.1103/PhysRevD.61.031301
IMSC-98/12/57
hep-ph
null
By combining the inputs from the neutrinoless double beta decay and the fits of cosmological models of dark matter with solar and atmospheric neutrino data, we obtain constraints on two of the mixing angles of Majorana neutrinos, which become stronger when coupled with the reactor neutrino data. These constraints are strong enough to rule out Majorana neutrinos if the small angle solution of solar neutrino puzzle is borne out.
[ { "created": "Mon, 14 Dec 1998 19:43:44 GMT", "version": "v1" }, { "created": "Tue, 15 Dec 1998 18:30:29 GMT", "version": "v2" }, { "created": "Tue, 29 Dec 1998 21:58:37 GMT", "version": "v3" }, { "created": "Wed, 6 Oct 1999 23:35:06 GMT", "version": "v4" } ]
2009-12-30
[ [ "Adhikari", "R.", "", "Matscience, Chennai" ], [ "Rajasekaran", "G.", "", "Matscience, Chennai" ] ]
By combining the inputs from the neutrinoless double beta decay and the fits of cosmological models of dark matter with solar and atmospheric neutrino data, we obtain constraints on two of the mixing angles of Majorana neutrinos, which become stronger when coupled with the reactor neutrino data. These constraints are strong enough to rule out Majorana neutrinos if the small angle solution of solar neutrino puzzle is borne out.
0903.1553
Rachid Benbrik
Abdesslam Arhrib, Rachid Benbrik, Chuan-Hung Chen
Lepton flavor violating tau decays in type-III seesaw mechanism
15 pages, 1 figure, to match version in press in Phys.Rev.D
Phys.Rev.D81:113003,2010
10.1103/PhysRevD.81.113003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the lepton flavor violating $\tau\to \ell P(V)$ ($P,V= \pi^0, \eta, \eta^{\prime}, \rho^0, \omega, \phi$) and $\tau\to 3\ell$ ($\ell = e, \mu$) decays are studied in the framework of the type-III seesaw model, in which new triplet fermions with a zero hypercharge (Y=0) interact with ordinary lepton doublets via Yukawa couplings, and affect tree-level leptonic Z-boson couplings. We investigate the experimental bound from the leptonic Z decay to get contraint on the exsiting parameters space. We predict that the upper limits on the branching ratios of $\tau\to \ell P(V)$ and $\tau\to 3\ell$ can reach the experimental current limits.
[ { "created": "Mon, 9 Mar 2009 13:12:48 GMT", "version": "v1" }, { "created": "Thu, 8 Apr 2010 04:45:04 GMT", "version": "v2" }, { "created": "Thu, 20 May 2010 02:57:43 GMT", "version": "v3" } ]
2014-11-18
[ [ "Arhrib", "Abdesslam", "" ], [ "Benbrik", "Rachid", "" ], [ "Chen", "Chuan-Hung", "" ] ]
In this paper, the lepton flavor violating $\tau\to \ell P(V)$ ($P,V= \pi^0, \eta, \eta^{\prime}, \rho^0, \omega, \phi$) and $\tau\to 3\ell$ ($\ell = e, \mu$) decays are studied in the framework of the type-III seesaw model, in which new triplet fermions with a zero hypercharge (Y=0) interact with ordinary lepton doublets via Yukawa couplings, and affect tree-level leptonic Z-boson couplings. We investigate the experimental bound from the leptonic Z decay to get contraint on the exsiting parameters space. We predict that the upper limits on the branching ratios of $\tau\to \ell P(V)$ and $\tau\to 3\ell$ can reach the experimental current limits.
hep-ph/0111382
Jian-jun Yang
Jian-Jun Yang (Santa Maria U. and Nanjing Normal U.)
$q \to \Lambda$ Fragmentation Function and Nucleon Transversity Distribution in a Diquark Model
Talk given in a seminar of U. Santa Maria
Nucl.Phys. A699 (2002) 562-578
10.1016/S0375-9474(01)01281-7
USM-TH-117
hep-ph
null
Based on a simple quark-diquark model, we propose a set of unpolarized, longitudinally polarized and transversely polarized fragmentation functions for the $\Lambda$ by fitting the unpolarized $\Lambda$ production data in $e^+ e ^- $ annihilation. It is found that the helicity structure of the obtained $\Lambda$ fragmentation functions is supported by the all available experimental data on the longitudinal $\Lambda$ polarization. Within the same framework of the diquark model, the nucleon transversity distributions are presented and consistent descriptions of the available HERMES data on the azimuthal spin asymmetries in pion electroproduction are obtained. Furthermore, the spin transfers to the transversely polarized $\Lambda$ in the charged lepton DIS on a transversely polarized nucleon target are predicted for future experiments.
[ { "created": "Wed, 28 Nov 2001 19:22:05 GMT", "version": "v1" } ]
2009-11-07
[ [ "Yang", "Jian-Jun", "", "Santa Maria U. and Nanjing Normal U." ] ]
Based on a simple quark-diquark model, we propose a set of unpolarized, longitudinally polarized and transversely polarized fragmentation functions for the $\Lambda$ by fitting the unpolarized $\Lambda$ production data in $e^+ e ^- $ annihilation. It is found that the helicity structure of the obtained $\Lambda$ fragmentation functions is supported by the all available experimental data on the longitudinal $\Lambda$ polarization. Within the same framework of the diquark model, the nucleon transversity distributions are presented and consistent descriptions of the available HERMES data on the azimuthal spin asymmetries in pion electroproduction are obtained. Furthermore, the spin transfers to the transversely polarized $\Lambda$ in the charged lepton DIS on a transversely polarized nucleon target are predicted for future experiments.
1407.8124
Holger Gies
Holger Gies and Ren\'e Sondenheimer
Higgs Mass Bounds from Renormalization Flow for a Higgs-top-bottom model
20 pages, 6 figures
null
10.1140/epjc/s10052-015-3284-1
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a chiral Yukawa model mimicking the Higgs-top-bottom sector of the standard model. We re-analyze the conventional arguments that relate a lower bound for the Higgs mass with vacuum stability in the light of exact results for the regularized fermion determinant as well as in the framework of the functional renormalization group. In both cases, we find no indication for vacuum instability nor meta-stability induced by top-fluctuations if the cutoff is kept finite but arbitrary. A lower bound for the Higgs mass arises for the class of standard bare potentials of \phi^4 type from the requirement of a well-defined functional integral (i.e., stability of the bare potential). This consistency bound can however be relaxed considerably by more general forms of the bare potential without necessarily introducing new meta-stable minima.
[ { "created": "Wed, 30 Jul 2014 16:55:50 GMT", "version": "v1" } ]
2015-06-22
[ [ "Gies", "Holger", "" ], [ "Sondenheimer", "René", "" ] ]
We study a chiral Yukawa model mimicking the Higgs-top-bottom sector of the standard model. We re-analyze the conventional arguments that relate a lower bound for the Higgs mass with vacuum stability in the light of exact results for the regularized fermion determinant as well as in the framework of the functional renormalization group. In both cases, we find no indication for vacuum instability nor meta-stability induced by top-fluctuations if the cutoff is kept finite but arbitrary. A lower bound for the Higgs mass arises for the class of standard bare potentials of \phi^4 type from the requirement of a well-defined functional integral (i.e., stability of the bare potential). This consistency bound can however be relaxed considerably by more general forms of the bare potential without necessarily introducing new meta-stable minima.
hep-ph/9902233
Yu. A. Simonov
Yu.A.Simonov (ITEP)
Perturbative-nonperturbative interference in the static QCD interaction at small distances
LaTeX, 13 pages, references added
Phys.Rept. 320 (1999) 265-274
10.1016/S0370-1573(99)00069-1
null
hep-ph
null
Short distance static quark--antiquark interaction is studied systematically using the background perturbation theory with nonperturbative background described by field correlators. A universal linear term $\frac{6N_c\alpha_s\sigma r}{2\pi}$ is observed at small distance $r$ due to the interference between perturbative and nonperturbative contributions. Possible modifications of this term due to additional subleading terms are discussed and implications for systematic corrections to OPE are formulated.
[ { "created": "Wed, 3 Feb 1999 16:47:36 GMT", "version": "v1" }, { "created": "Mon, 15 Feb 1999 16:54:30 GMT", "version": "v2" }, { "created": "Tue, 30 Mar 1999 14:30:34 GMT", "version": "v3" } ]
2009-10-31
[ [ "Simonov", "Yu. A.", "", "ITEP" ] ]
Short distance static quark--antiquark interaction is studied systematically using the background perturbation theory with nonperturbative background described by field correlators. A universal linear term $\frac{6N_c\alpha_s\sigma r}{2\pi}$ is observed at small distance $r$ due to the interference between perturbative and nonperturbative contributions. Possible modifications of this term due to additional subleading terms are discussed and implications for systematic corrections to OPE are formulated.
1502.04718
Giacomo Cacciapaglia
Alexandre Arbey, Giacomo Cacciapaglia, Haiying Cai, Aldo Deandrea, Solene Le Corre and Francesco Sannino
Fundamental Composite Electroweak Dynamics: Status at the LHC
30 pages, 8 figures
Phys. Rev. D 95, 015028 (2017)
10.1103/PhysRevD.95.015028
CERN-PH-TH/2015-027, LYCEN 2015-02, CP3-Origins-2015-007
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the current status of the fundamental composite electroweak dynamics paradigm after the discovery of the Higgs boson at the Large Hadron Collider experiments. Our analysis serves as universal and minimal template for a wide class of models with the two limits in parameter space being composite Goldstone Higgs models and Technicolor. This is possible because of the existence of a unified description, both at the effective and fundamental Lagrangian levels, of models of composite Higgs dynamics where the Higgs boson itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation of the condensate. We constrain the available parameter space at the effective Lagrangian level. We show that a wide class of models of fundamental composite electroweak dynamics, including Technicolor, are compatible with experiments. The results are relevant for future searches of a fundamental composite nature of the Higgs mechanism at the Large Hadron Collider.
[ { "created": "Mon, 16 Feb 2015 21:06:12 GMT", "version": "v1" } ]
2017-02-08
[ [ "Arbey", "Alexandre", "" ], [ "Cacciapaglia", "Giacomo", "" ], [ "Cai", "Haiying", "" ], [ "Deandrea", "Aldo", "" ], [ "Corre", "Solene Le", "" ], [ "Sannino", "Francesco", "" ] ]
We determine the current status of the fundamental composite electroweak dynamics paradigm after the discovery of the Higgs boson at the Large Hadron Collider experiments. Our analysis serves as universal and minimal template for a wide class of models with the two limits in parameter space being composite Goldstone Higgs models and Technicolor. This is possible because of the existence of a unified description, both at the effective and fundamental Lagrangian levels, of models of composite Higgs dynamics where the Higgs boson itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation of the condensate. We constrain the available parameter space at the effective Lagrangian level. We show that a wide class of models of fundamental composite electroweak dynamics, including Technicolor, are compatible with experiments. The results are relevant for future searches of a fundamental composite nature of the Higgs mechanism at the Large Hadron Collider.
hep-ph/0407095
Thomas Fritzsche
T. Fritzsche and W. Hollik
One-loop calculations for SUSY processes
Talk presented at Loops and Legs in Quantum Field Theory, Zinnowitz, Germany, April 2004
null
10.1016/j.nuclphysbps.2004.09.043
MPP-2004-83
hep-ph
null
Strategy and results for complete one-loop computations in the Minimal Supersymmetric Standard Model are reviewed, with applications to the calculation of SUSY mass spectra and SUSY-particle processes. Determination of renormalization constants and counterterms are described in the on-shell renormalization scheme, and a translation between $\bar{\rm DR}$ and on-shell parameters is given. As an example, cross sections for chargino and neutralino pair production in $e^+e^-$ annihilation are presented, complete at the one-loop level.
[ { "created": "Thu, 8 Jul 2004 09:43:15 GMT", "version": "v1" } ]
2009-11-10
[ [ "Fritzsche", "T.", "" ], [ "Hollik", "W.", "" ] ]
Strategy and results for complete one-loop computations in the Minimal Supersymmetric Standard Model are reviewed, with applications to the calculation of SUSY mass spectra and SUSY-particle processes. Determination of renormalization constants and counterterms are described in the on-shell renormalization scheme, and a translation between $\bar{\rm DR}$ and on-shell parameters is given. As an example, cross sections for chargino and neutralino pair production in $e^+e^-$ annihilation are presented, complete at the one-loop level.
hep-ph/0503002
Gaetano Lambiase
G. Lambiase
Effects of CPT and Lorentz Invariance Violation on Pulsar Kicks
10 pages, 1 figure
Phys.Rev. D71 (2005) 065005
10.1103/PhysRevD.71.065005
null
hep-ph astro-ph gr-qc
null
The breakdown of Lorentz's and CPT invariance, as described by the Extension of the Standard Model, gives rise to a modification of the dispersion relation of particles. Consequences of such a modification are reviewed in the framework of pulsar kicks induced by neutrino oscillations (active-sterile conversion). A peculiar feature of the modified energy-momentum relations is the occurrence of terms of the form $\delta {\bbox \Pi}\cdot {\bf {\hat p}}$, where $\delta {\bbox \Pi}$ accounts for the difference of spatial components of flavor depending coefficients which lead to the departure of the Lorentz symmetry, and ${\bf {\hat p}}={\bf p}/p$, being ${\bf p}$ the neutrino momentum. Owing to the relative orientation of ${\bf p}$ with respect to $\delta {\bbox \Pi}$, the {\it coupling} $\delta {\bbox \Pi}\cdot {\bf {\hat p}}$ may induce the mechanism to generate the observed pulsar velocities. Topics related to the velocity distribution of pulsars are also discussed.
[ { "created": "Tue, 1 Mar 2005 00:11:56 GMT", "version": "v1" } ]
2009-11-11
[ [ "Lambiase", "G.", "" ] ]
The breakdown of Lorentz's and CPT invariance, as described by the Extension of the Standard Model, gives rise to a modification of the dispersion relation of particles. Consequences of such a modification are reviewed in the framework of pulsar kicks induced by neutrino oscillations (active-sterile conversion). A peculiar feature of the modified energy-momentum relations is the occurrence of terms of the form $\delta {\bbox \Pi}\cdot {\bf {\hat p}}$, where $\delta {\bbox \Pi}$ accounts for the difference of spatial components of flavor depending coefficients which lead to the departure of the Lorentz symmetry, and ${\bf {\hat p}}={\bf p}/p$, being ${\bf p}$ the neutrino momentum. Owing to the relative orientation of ${\bf p}$ with respect to $\delta {\bbox \Pi}$, the {\it coupling} $\delta {\bbox \Pi}\cdot {\bf {\hat p}}$ may induce the mechanism to generate the observed pulsar velocities. Topics related to the velocity distribution of pulsars are also discussed.
1711.02862
Pilar Hernandez
M. Drewes, B. Garbrecht, P. Hernandez, M. Kekic, J. Lopez-Pavon, J. Racker, N. Rius, J. Salvado and D. Teresi
ARS Leptogenesis
46 pages, 8 figures. Chapter 2 of the review volume: Leptogenesis: Current Challenges for Model Building, Phenomenology and Non-Equilibrium Field Theory
null
10.1142/S0217751X18420022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the current status of the leptogenesis scenario originally proposed by Akhmedov, Rubakov and Smirnov (ARS). It takes place in the parametric regime where the right-handed neutrinos are at the electroweak scale or below and the CP-violating effects are induced by the coherent superposition of different right-handed mass eigenstates. Two main theoretical approaches to derive quantum kinetic equations, the Hamiltonian time evolution as well as the Closed-Time-Path technique are presented, and we discuss their relations. For scenarios with two right-handed neutrinos, we chart the viable parameter space. Both, a Bayesian analysis, that determines the most likely configurations for viable leptogenesis given different variants of flat priors, and a determination of the maximally allowed mixing between the light, mostly left-handed, and heavy, mostly right-handed, neutrino states are discussed. Rephasing invariants are shown to be a useful tool to classify and to understand various distinct contributions to ARS leptogenesis that can dominate in different parametric regimes. While these analyses are carried out for the parametric regime where initial asymmetries are generated predominantly from lepton-number conserving, but flavor violating effects, we also review the contributions from lepton-number violating operators and identify the regions of parameter space where these are relevant.
[ { "created": "Wed, 8 Nov 2017 08:15:05 GMT", "version": "v1" } ]
2018-04-04
[ [ "Drewes", "M.", "" ], [ "Garbrecht", "B.", "" ], [ "Hernandez", "P.", "" ], [ "Kekic", "M.", "" ], [ "Lopez-Pavon", "J.", "" ], [ "Racker", "J.", "" ], [ "Rius", "N.", "" ], [ "Salvado", "J.", ...
We review the current status of the leptogenesis scenario originally proposed by Akhmedov, Rubakov and Smirnov (ARS). It takes place in the parametric regime where the right-handed neutrinos are at the electroweak scale or below and the CP-violating effects are induced by the coherent superposition of different right-handed mass eigenstates. Two main theoretical approaches to derive quantum kinetic equations, the Hamiltonian time evolution as well as the Closed-Time-Path technique are presented, and we discuss their relations. For scenarios with two right-handed neutrinos, we chart the viable parameter space. Both, a Bayesian analysis, that determines the most likely configurations for viable leptogenesis given different variants of flat priors, and a determination of the maximally allowed mixing between the light, mostly left-handed, and heavy, mostly right-handed, neutrino states are discussed. Rephasing invariants are shown to be a useful tool to classify and to understand various distinct contributions to ARS leptogenesis that can dominate in different parametric regimes. While these analyses are carried out for the parametric regime where initial asymmetries are generated predominantly from lepton-number conserving, but flavor violating effects, we also review the contributions from lepton-number violating operators and identify the regions of parameter space where these are relevant.
0902.1055
J.D. Vergados
J.D. Vergados (University of Ioannina, Ioannina, Greece), F.T. Avignone III (University of South Carolina, Columbia, USA), I. Giomataris (CEA, Saclay, DAPNIA, Gif-sur-Yvette, Cedex, France)
Coherent Neutral Current Neutrino-Nucleus Scattering at a Spallation Source; a Valuable Experimental Probe
15 LaTex pages, 14 figures, 3 Tables
Phys.Rev.D79:113001,2009
10.1103/PhysRevD.79.113001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The coherent contribution of all neutrons in neutrino nucleus scattering due to the neutral current is examined considering the Spallation Neutron Source (SNS) as a source of neutrinos. SNS is a prolific pulsed source of electron and muon neutrinos as well as muon antineutrinos.
[ { "created": "Fri, 6 Feb 2009 10:42:05 GMT", "version": "v1" } ]
2009-06-30
[ [ "Vergados", "J. D.", "", "University of Ioannina, Ioannina, Greece" ], [ "Avignone", "F. T.", "III", "University of South Carolina, Columbia, USA" ], [ "Giomataris", "I.", "", "CEA, Saclay, DAPNIA, Gif-sur-Yvette, Cedex, France" ] ]
The coherent contribution of all neutrons in neutrino nucleus scattering due to the neutral current is examined considering the Spallation Neutron Source (SNS) as a source of neutrinos. SNS is a prolific pulsed source of electron and muon neutrinos as well as muon antineutrinos.
1411.1731
Kevin Ludwick
Pham Q. Hung and Kevin J. Ludwick
Constraining Inflationary Dark Matter in the Luminogenesis Model
Added section reviewing model, removed unecessary section; 13 pages, 4 figures
JCAP09(2015)031
10.1088/1475-7516/2015/09/031
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using renormalization-group flow and cosmological constraints on inflation models, we exploit a unique connection between cosmological inflation and the dynamical mass of dark-matter particles in the luminogenesis model, a unification model with the gauge group $SU(3)_C \times SU(6) \times U(1)_Y$, which breaks to the Standard Model with an extra gauge group for dark matter when the inflaton rolls into the true vacuum. In this model, inflaton decay gives rise to dark matter, which in turn decays to luminous matter in the right proportion that agrees with cosmological data. Some attractive features of this model include self-interacting dark matter, which may resolve the problems of dwarf-galaxy structures and dark-matter cusps at the centers of galaxies.
[ { "created": "Thu, 6 Nov 2014 20:20:45 GMT", "version": "v1" }, { "created": "Tue, 11 Nov 2014 16:18:44 GMT", "version": "v2" }, { "created": "Wed, 6 May 2015 15:03:48 GMT", "version": "v3" }, { "created": "Thu, 17 Sep 2015 22:07:54 GMT", "version": "v4" } ]
2015-12-02
[ [ "Hung", "Pham Q.", "" ], [ "Ludwick", "Kevin J.", "" ] ]
Using renormalization-group flow and cosmological constraints on inflation models, we exploit a unique connection between cosmological inflation and the dynamical mass of dark-matter particles in the luminogenesis model, a unification model with the gauge group $SU(3)_C \times SU(6) \times U(1)_Y$, which breaks to the Standard Model with an extra gauge group for dark matter when the inflaton rolls into the true vacuum. In this model, inflaton decay gives rise to dark matter, which in turn decays to luminous matter in the right proportion that agrees with cosmological data. Some attractive features of this model include self-interacting dark matter, which may resolve the problems of dwarf-galaxy structures and dark-matter cusps at the centers of galaxies.
2406.03100
Jia-Shu Niu
Jia-Shu Niu
Exploring the Dark Frontier: White Dwarf-Based Constraints on Light Dark Matter
8 pages (including Supplementary Material), 1 figure, 1 table. Comments are welcomed
null
null
null
hep-ph astro-ph.CO astro-ph.HE astro-ph.SR
http://creativecommons.org/licenses/by/4.0/
In the vast expanse of our galaxy, white dwarfs (WDs) are natural sentinels, capturing the enigmatic dark matter (DM) particles that incessantly traverse their interiors. These celestial bodies provide a unique vantage point for probing interactions between DM particles and their constituents-nuclei or electrons-should such interactions exist. The captured DM particles may accumulate, undergo mutual annihilation, or be evaporated by the WD's own nuclei or electrons, thereby perturbing the standard cooling sequence predicted by stellar evolution theory. This letter reports pioneering constraints on DM-electron interactions derived from an in-depth analysis of four pulsating WDs. By leveraging the period variation rates of their pulsation modes, we delineate the following constraints: for a form factor $F(q) = 1$, in the DM mass range $20 \mathrm{MeV}/c^{2} \lesssim m_{\chi} \lesssim 80 \mathrm{MeV}/c^{2}$ with a cross-section limit of $\sigma_{\chi,e} \lesssim 10^{-56} \mathrm{cm}^{2}$; for a form factor $F(q) = (\alpha m_{e})^{2}/q^{2}$, in a the DM mass range $20\mathrm{MeV}/c^{2} \lesssim m_{\chi} \lesssim 70 \mathrm{MeV}/c^{2}$ with a limit of $\sigma_{\chi,e} \lesssim 10^{-52} \mathrm{cm}^{2}$. These newly established constraints surpass current direct detection experiments by over fifteen orders of magnitude, forging a path into the uncharted territories of the DM parameter space. This work not only advances our understanding of light dark matter-electron interactions but also exemplifies the potential of WDs as important astrophysical laboratories for probing the elusive nature of DM.
[ { "created": "Wed, 5 Jun 2024 09:43:55 GMT", "version": "v1" } ]
2024-06-06
[ [ "Niu", "Jia-Shu", "" ] ]
In the vast expanse of our galaxy, white dwarfs (WDs) are natural sentinels, capturing the enigmatic dark matter (DM) particles that incessantly traverse their interiors. These celestial bodies provide a unique vantage point for probing interactions between DM particles and their constituents-nuclei or electrons-should such interactions exist. The captured DM particles may accumulate, undergo mutual annihilation, or be evaporated by the WD's own nuclei or electrons, thereby perturbing the standard cooling sequence predicted by stellar evolution theory. This letter reports pioneering constraints on DM-electron interactions derived from an in-depth analysis of four pulsating WDs. By leveraging the period variation rates of their pulsation modes, we delineate the following constraints: for a form factor $F(q) = 1$, in the DM mass range $20 \mathrm{MeV}/c^{2} \lesssim m_{\chi} \lesssim 80 \mathrm{MeV}/c^{2}$ with a cross-section limit of $\sigma_{\chi,e} \lesssim 10^{-56} \mathrm{cm}^{2}$; for a form factor $F(q) = (\alpha m_{e})^{2}/q^{2}$, in a the DM mass range $20\mathrm{MeV}/c^{2} \lesssim m_{\chi} \lesssim 70 \mathrm{MeV}/c^{2}$ with a limit of $\sigma_{\chi,e} \lesssim 10^{-52} \mathrm{cm}^{2}$. These newly established constraints surpass current direct detection experiments by over fifteen orders of magnitude, forging a path into the uncharted territories of the DM parameter space. This work not only advances our understanding of light dark matter-electron interactions but also exemplifies the potential of WDs as important astrophysical laboratories for probing the elusive nature of DM.
1910.00534
Xavier Calmet
Xavier Calmet
Cosmological Time Evolution of the Higgs Mass and Gravitational Waves
null
null
10.1142/S0217751X20400357
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out that gravitational wave detectors such as LISA have the potential of probing a cosmological time evolution of the Higgs boson self-coupling constant $\lambda$ and thus the Higgs boson's mass $m_H= \sqrt{ 2 \lambda} v$. The phase transition of the Standard Model could have been a first order one if the Higgs mass was below 72 GeV at a temperature $T_\star \ge 100$ GeV. Gravitational waves could thus have been produced during the electroweak phase transition. A discovery by LISA of a stochastic background of gravitational waves with a characteristic frequency $k_\star \ge 10^{-5}$ Hz could be interpreted as a sign that the Higgs boson self-coupling constant was smaller in the past. This interpretation would be particularly tempting if the Large Hadron Collider did not discover any physics beyond the Standard Model by the time such waves are seen. The same mechanism could also account for baryogenesis.
[ { "created": "Tue, 1 Oct 2019 16:39:36 GMT", "version": "v1" } ]
2020-03-18
[ [ "Calmet", "Xavier", "" ] ]
We point out that gravitational wave detectors such as LISA have the potential of probing a cosmological time evolution of the Higgs boson self-coupling constant $\lambda$ and thus the Higgs boson's mass $m_H= \sqrt{ 2 \lambda} v$. The phase transition of the Standard Model could have been a first order one if the Higgs mass was below 72 GeV at a temperature $T_\star \ge 100$ GeV. Gravitational waves could thus have been produced during the electroweak phase transition. A discovery by LISA of a stochastic background of gravitational waves with a characteristic frequency $k_\star \ge 10^{-5}$ Hz could be interpreted as a sign that the Higgs boson self-coupling constant was smaller in the past. This interpretation would be particularly tempting if the Large Hadron Collider did not discover any physics beyond the Standard Model by the time such waves are seen. The same mechanism could also account for baryogenesis.
1601.02113
Lorenzo Magnea
Lorenzo Magnea
The growing toolbox of perturbative QCD
Talk given at the Workshop "LFC15: Physics Prospects for Linear and Other Future Colliders", ECT*, Trento, 7-11 September 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Advances in perturbative QCD techniques have been crucial for the successful interpretation of the data collected in Run I of LHC, and for the discovery of the Higgs boson. I will very briefly highlight some recent additions to the QCD toolbox, and note how these new tools are likely to be essential for future precision physics, both in Run II at the LHC, and in view of future hadron and lepton colliders.
[ { "created": "Sat, 9 Jan 2016 14:02:42 GMT", "version": "v1" } ]
2016-01-12
[ [ "Magnea", "Lorenzo", "" ] ]
Advances in perturbative QCD techniques have been crucial for the successful interpretation of the data collected in Run I of LHC, and for the discovery of the Higgs boson. I will very briefly highlight some recent additions to the QCD toolbox, and note how these new tools are likely to be essential for future precision physics, both in Run II at the LHC, and in view of future hadron and lepton colliders.