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hep-ph/0310029
Pawel Jankowski
F.Cornet (Granada U.), P.Jankowski (Warsaw U.), M.Krawczyk (Warsaw U)
CJK- Improved LO Parton Distributions in the Real Photon and Their Experimental Uncertainties
Prepared for Photon 2003: International Conference on the Structure and Interactions of the Photon (Including the 15th International Workshop on Photon-Photon Collisions), Frascati (Italy), 7-11 April 2003; 10 pages, Latex using espcrc2 style, 1 tex and 5 postscript figures; FORTRAN programs available at http://www.fuw.edu.pl/~pjank/param.html
Nucl.Phys.Proc.Suppl.126:28-37,2004
10.1016/S0920-5632(03)02304-1
ITF-2003-28, UG-FT-155/03, CAFPE-25/03
hep-ph
null
A new analysis of the radiatively generated, LO quark (u,d,s,c,b) and gluon densities in the real, unpolarized photon, improved in respect to our paper [1], is presented. We perform four new global fits to the experimental data for F2^gamma, two using a standard FFNS approach and two based on ACOT(chi) scheme [2], leading to the FFNS(CJK) and CJK models. We also present the analysis of the uncertainties of the new CJK 2 parton distributions due to the experimental errors, the very first such analysis performed for the photon. This analysis is based on the Hessian method, for a comparison for chosen cross-sections we use also the Lagrange method.
[ { "created": "Thu, 2 Oct 2003 11:26:00 GMT", "version": "v1" } ]
2011-01-25
[ [ "Cornet", "F.", "", "Granada U." ], [ "Jankowski", "P.", "", "Warsaw U." ], [ "Krawczyk", "M.", "", "Warsaw U" ] ]
A new analysis of the radiatively generated, LO quark (u,d,s,c,b) and gluon densities in the real, unpolarized photon, improved in respect to our paper [1], is presented. We perform four new global fits to the experimental data for F2^gamma, two using a standard FFNS approach and two based on ACOT(chi) scheme [2], leading to the FFNS(CJK) and CJK models. We also present the analysis of the uncertainties of the new CJK 2 parton distributions due to the experimental errors, the very first such analysis performed for the photon. This analysis is based on the Hessian method, for a comparison for chosen cross-sections we use also the Lagrange method.
1705.00263
Fred Jegerlehner
Fred Jegerlehner
Muon g-2 Theory: the Hadronic Part
17 pages, 26 figures
null
10.1051/epjconf/201816600022
DESY 17-058, HU-EP-17/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present a status report of the hadronic vacuum polarization effects for the muon $g-2$, to be considered as an update of [1]. The update concerns recent new inclusive $R$ measurements from KEDR in the energy range 1.84 to 3.72 GeV. For the leading order contributions I find $a_\mu^{\mathrm{had}(1)}=(688.07\pm 4.14)[688.77\pm3.38]\times 10^{-10}$ based on $e^+e^-$data [incl. $\tau$ data], $a_\mu^{\mathrm{had}(2)}= (-9.93\pm 0.07) \times 10^{-10}$ (NLO) and $a_\mu^{\mathrm{had}(3)}= (1.22\pm 0.01) \times 10^{-10}$ (NNLO). Collecting recent progress in the hadronic light-by-light scattering I adopt $\pi^0,\eta,\eta'$ [$95 \pm 12$] + axial--vector [$8 \pm ~3$] + scalar [$-6\pm ~1$] + $\pi,K$ loops [$-20\pm 5$] + quark loops [$22\pm ~4$] + tensor [$1\pm ~0$] + NLO [$3\pm ~2$] which yields $ a^{(6)}_\mu(\mathrm{lbl},\mathrm{had})=(103 \pm 29) \times 10^{-11}.$ With these updates I find $a_\mu^{\rm exp}-a_\mu^{\rm the}=(31.3\pm 7.7)\times 10^{-10}$ a 4.1 $\sigma$ deviation. Recent lattice QCD results and future prospects to improve hadronic contributions are discussed.
[ { "created": "Sun, 30 Apr 2017 02:30:23 GMT", "version": "v1" } ]
2018-02-14
[ [ "Jegerlehner", "Fred", "" ] ]
I present a status report of the hadronic vacuum polarization effects for the muon $g-2$, to be considered as an update of [1]. The update concerns recent new inclusive $R$ measurements from KEDR in the energy range 1.84 to 3.72 GeV. For the leading order contributions I find $a_\mu^{\mathrm{had}(1)}=(688.07\pm 4.14)[688.77\pm3.38]\times 10^{-10}$ based on $e^+e^-$data [incl. $\tau$ data], $a_\mu^{\mathrm{had}(2)}= (-9.93\pm 0.07) \times 10^{-10}$ (NLO) and $a_\mu^{\mathrm{had}(3)}= (1.22\pm 0.01) \times 10^{-10}$ (NNLO). Collecting recent progress in the hadronic light-by-light scattering I adopt $\pi^0,\eta,\eta'$ [$95 \pm 12$] + axial--vector [$8 \pm ~3$] + scalar [$-6\pm ~1$] + $\pi,K$ loops [$-20\pm 5$] + quark loops [$22\pm ~4$] + tensor [$1\pm ~0$] + NLO [$3\pm ~2$] which yields $ a^{(6)}_\mu(\mathrm{lbl},\mathrm{had})=(103 \pm 29) \times 10^{-11}.$ With these updates I find $a_\mu^{\rm exp}-a_\mu^{\rm the}=(31.3\pm 7.7)\times 10^{-10}$ a 4.1 $\sigma$ deviation. Recent lattice QCD results and future prospects to improve hadronic contributions are discussed.
2203.07827
Wolfgang Sch\"afer
Anna Cisek, Wolfgang Sch\"afer, Antoni Szczurek
Structure and production mechanism of the enigmatic $X(3872)$ in high-energy hadronic reactions
17 pages, 7 figures, v2: references added, v3: a diagram added, minor changes
null
10.1140/epjc/s10052-022-11029-x
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We calculate the total cross section and transverse momentum distributions for the production of enigmatic $\chi_{c,1}(3872)$ (or X(3872)) assuming different scenarios: $c \bar c$ state and $D^{0*} {\bar D}^0 + D^0 {\bar D}^{0*}$ molecule. The derivative of the $c \bar c$ wave function needed in the first scenario is taken from a potential model calculations. Compared to earlier calculation of molecular state we include not only single parton scattering (SPS) but also double parton scattering (DPS) contributions. The latter one seems to give smaller contribution than the SPS one. The upper limit for the DPS production of $\chi_{c,1}(3872)$ is much below the CMS data. We compare results of our calculations with existing experimental data of CMS, ATLAS and LHCb collaborations. Reasonable cross sections can be obtained in either $c \bar c$ or molecular $D {\bar D}^*$ scenarios for $X(3872)$. Also a hybrid scenario is not excluded.
[ { "created": "Tue, 15 Mar 2022 12:30:01 GMT", "version": "v1" }, { "created": "Mon, 21 Mar 2022 08:30:50 GMT", "version": "v2" }, { "created": "Fri, 20 May 2022 08:57:52 GMT", "version": "v3" } ]
2022-12-14
[ [ "Cisek", "Anna", "" ], [ "Schäfer", "Wolfgang", "" ], [ "Szczurek", "Antoni", "" ] ]
We calculate the total cross section and transverse momentum distributions for the production of enigmatic $\chi_{c,1}(3872)$ (or X(3872)) assuming different scenarios: $c \bar c$ state and $D^{0*} {\bar D}^0 + D^0 {\bar D}^{0*}$ molecule. The derivative of the $c \bar c$ wave function needed in the first scenario is taken from a potential model calculations. Compared to earlier calculation of molecular state we include not only single parton scattering (SPS) but also double parton scattering (DPS) contributions. The latter one seems to give smaller contribution than the SPS one. The upper limit for the DPS production of $\chi_{c,1}(3872)$ is much below the CMS data. We compare results of our calculations with existing experimental data of CMS, ATLAS and LHCb collaborations. Reasonable cross sections can be obtained in either $c \bar c$ or molecular $D {\bar D}^*$ scenarios for $X(3872)$. Also a hybrid scenario is not excluded.
0707.0677
Roman Zwicky
Roman Zwicky
Unparticles at heavy flavour scales: CP violating phenomena
33 pages, 9 figures
Phys.Rev.D77:036004,2008
10.1103/PhysRevD.77.036004
DCPT/07/58, IPPP/07/29
hep-ph
null
Coupling the scale invariant unparticle sector to flavour physics and assuming that it remains scale invariant we investigate its consequences in heavy flavour physics. A drastic feature of unparticle physics is an unusual phase leading to novel CP violating phenomena. We consider the CP asymmetry in the leptonic decay B^+ -> tau^+ nu and the hadronic decay B_d -> D^+D^-, taking into account constraints of branching ratios and time dependent CP asymmetries. Generic plots are shown and it turns out that there exist parameters for which the CP violation is maximal. A prediction of a large CP asymmetry in B_d -> D^+D^- is difficult to achieve in other models without contradicting the current data in other channels. The prediction of a CP asymmetry in leptonic decays, such as B^+ -> tau^+ nu, is novel. We identify the CP compensating mode due to the unparticles and show explicitly that it exactly cancels the CP asymmetry of B^+ -> tau^+ nu as demanded by CPT invariance. Building up on earlier works we investigate the breaking of scale invaricance, due to the coupling to the Higgs and the size of the effects in the weak sector resorting to a dimensional analysis. An enhancement is observed on the grounds of the relevance of the unparticle interaction operator as compared to the weak four-Fermi term.
[ { "created": "Wed, 4 Jul 2007 18:25:34 GMT", "version": "v1" } ]
2008-11-26
[ [ "Zwicky", "Roman", "" ] ]
Coupling the scale invariant unparticle sector to flavour physics and assuming that it remains scale invariant we investigate its consequences in heavy flavour physics. A drastic feature of unparticle physics is an unusual phase leading to novel CP violating phenomena. We consider the CP asymmetry in the leptonic decay B^+ -> tau^+ nu and the hadronic decay B_d -> D^+D^-, taking into account constraints of branching ratios and time dependent CP asymmetries. Generic plots are shown and it turns out that there exist parameters for which the CP violation is maximal. A prediction of a large CP asymmetry in B_d -> D^+D^- is difficult to achieve in other models without contradicting the current data in other channels. The prediction of a CP asymmetry in leptonic decays, such as B^+ -> tau^+ nu, is novel. We identify the CP compensating mode due to the unparticles and show explicitly that it exactly cancels the CP asymmetry of B^+ -> tau^+ nu as demanded by CPT invariance. Building up on earlier works we investigate the breaking of scale invaricance, due to the coupling to the Higgs and the size of the effects in the weak sector resorting to a dimensional analysis. An enhancement is observed on the grounds of the relevance of the unparticle interaction operator as compared to the weak four-Fermi term.
0803.3450
Pavel Fileviez Perez
Pavel Fileviez Perez, Tao Han, Gui-Yu Huang, Tong Li, Kai Wang
Testing a Neutrino Mass Generation Mechanism at the Large Hadron Collider
5 pages, 4 figures, published in PRD Rapid Communication
Phys.Rev.D78:071301,2008
10.1103/PhysRevD.78.071301
MADPH-08-1505, NSF-KITP-08-36
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Large Hadron Collider could be a discovery machine for the neutrino mass pattern and its Majorana nature in the context of a well-motivated TeV scale Type II seesaw model. This is achieved by identifying the flavor structure of the lepton number violating decays of the charged Higgs bosons. The observation of either H^+ --> tau^+ nubar or H^+ --> e^+ nubar will be particularly robust to determine the neutrino spectra since they are independent of the unknown Majorana phases, which could be probed via the H^{++} --> e^+_i e^+_j decays. In a less favorable scenario when the leptonic channels are suppressed, one needs to observe the decays H^+ --> W^+ H_1, and H^+ --> t bbar to confirm the triplet-doublet mixing that implies the Type II relation. The associated production H^{++} H^{-} is crucial in order to test the triplet nature of the Higgs field.
[ { "created": "Mon, 24 Mar 2008 22:36:23 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 2008 00:11:28 GMT", "version": "v2" } ]
2008-10-09
[ [ "Perez", "Pavel Fileviez", "" ], [ "Han", "Tao", "" ], [ "Huang", "Gui-Yu", "" ], [ "Li", "Tong", "" ], [ "Wang", "Kai", "" ] ]
The Large Hadron Collider could be a discovery machine for the neutrino mass pattern and its Majorana nature in the context of a well-motivated TeV scale Type II seesaw model. This is achieved by identifying the flavor structure of the lepton number violating decays of the charged Higgs bosons. The observation of either H^+ --> tau^+ nubar or H^+ --> e^+ nubar will be particularly robust to determine the neutrino spectra since they are independent of the unknown Majorana phases, which could be probed via the H^{++} --> e^+_i e^+_j decays. In a less favorable scenario when the leptonic channels are suppressed, one needs to observe the decays H^+ --> W^+ H_1, and H^+ --> t bbar to confirm the triplet-doublet mixing that implies the Type II relation. The associated production H^{++} H^{-} is crucial in order to test the triplet nature of the Higgs field.
hep-ph/0211014
Lorenzo Magnea
S. Forte, J.I. Latorre, L. Magnea and A. Piccione
A determination of alpha_s from scaling violations with truncated moments
5 pages, no figures. Talk given by L. Magnea at QCD02, Montpellier, July 2002
Nucl.Phys.Proc.Suppl.121:46-50,2003
10.1016/S0920-5632(03)01810-3
DFTT 36/02
hep-ph
null
We describe a determination of the strong coupling alpha_s(M_Z) from scaling violations of the nonsinglet DIS structure function, which is based on two novel techniques aimed at controlling and minimizing the theoretical error: a neural network parametrization of BCDMS and NMC data, and QCD evolution by means of truncated Mellin moments.
[ { "created": "Fri, 1 Nov 2002 18:02:53 GMT", "version": "v1" } ]
2014-11-17
[ [ "Forte", "S.", "" ], [ "Latorre", "J. I.", "" ], [ "Magnea", "L.", "" ], [ "Piccione", "A.", "" ] ]
We describe a determination of the strong coupling alpha_s(M_Z) from scaling violations of the nonsinglet DIS structure function, which is based on two novel techniques aimed at controlling and minimizing the theoretical error: a neural network parametrization of BCDMS and NMC data, and QCD evolution by means of truncated Mellin moments.
1803.02521
Bao-Dong Sun
Bao-Dong Sun and Yu-Bing Dong
$\rho$ meson impact parameter distributions
null
Chinese Physics C (2018)
10.1088/1674-1137/42/6/063104
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the $\rho$ meson impact parameter dependent parton distributions and the impact parameter dependent form factors are introduced and discussed. By employing a Gaussian form wave packet, we calculate the impact parameter distributions of $\rho$ meson based on a light-front constituent quark model.
[ { "created": "Wed, 7 Mar 2018 04:28:21 GMT", "version": "v1" }, { "created": "Tue, 15 May 2018 10:05:30 GMT", "version": "v2" } ]
2018-05-16
[ [ "Sun", "Bao-Dong", "" ], [ "Dong", "Yu-Bing", "" ] ]
In this paper, the $\rho$ meson impact parameter dependent parton distributions and the impact parameter dependent form factors are introduced and discussed. By employing a Gaussian form wave packet, we calculate the impact parameter distributions of $\rho$ meson based on a light-front constituent quark model.
hep-ph/9911469
Sergey Goloskokov
S.V.Goloskokov
Diffractive hadron production and pomeron coupling structure
6 pages, latex, 4 figures, to be published in Proc. of the International Bogolyubov Conference "Problems of Theoretical and Mathematical Physics", September 27- October 6, Moscow-Dubna-Kyiv
null
null
null
hep-ph
null
Large-distance effects, which lead to the spin-flip part of the hadron -pomeron coupling in QCD -models, are discussed. We study spin asymmetries in exclusive reactions and in diffractive $Q \bar Q$ and vector meson production which are sensitive to the spin-dependent part of the pomeron coupling.
[ { "created": "Wed, 24 Nov 1999 14:23:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Goloskokov", "S. V.", "" ] ]
Large-distance effects, which lead to the spin-flip part of the hadron -pomeron coupling in QCD -models, are discussed. We study spin asymmetries in exclusive reactions and in diffractive $Q \bar Q$ and vector meson production which are sensitive to the spin-dependent part of the pomeron coupling.
1601.07391
Andrea Lami
A. Lami, J. Portoles (IFIC, Valencia) and P. Roig (Cinvestav, Mexico)
Lepton Flavour Violation in Hadron Decays of the Tau Lepton in the Simplest Little Higgs Model
13 pages, 13 Figures
Phys. Rev. D 93, 076008 (2016)
10.1103/PhysRevD.93.076008
IFIC/16-04
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study Lepton Flavour Violating hadron decays of the tau lepton within the Simplest Little Higgs model. Namely we consider $\tau \rightarrow \mu (P, V, PP)$ where $P$ and $V$ are short for a pseudoscalar and a vector meson. We find that, in the most positive scenarios, branching ratios for these processes are predicted to be, at least, four orders of magnitude smaller than present experimental bounds.
[ { "created": "Wed, 27 Jan 2016 14:44:00 GMT", "version": "v1" } ]
2016-04-25
[ [ "Lami", "A.", "", "IFIC, Valencia" ], [ "Portoles", "J.", "", "IFIC, Valencia" ], [ "Roig", "P.", "", "Cinvestav, Mexico" ] ]
We study Lepton Flavour Violating hadron decays of the tau lepton within the Simplest Little Higgs model. Namely we consider $\tau \rightarrow \mu (P, V, PP)$ where $P$ and $V$ are short for a pseudoscalar and a vector meson. We find that, in the most positive scenarios, branching ratios for these processes are predicted to be, at least, four orders of magnitude smaller than present experimental bounds.
1807.09615
Kolja Kauder
Kolja Kauder (for the JETSCAPE Collaboration)
JETSCAPE v1.0 Quickstart Guide
Proceedings of Quark Matter 2018, submitted to Nuclear Physics A. 4 pages, 2 figures
null
10.1016/j.nuclphysa.2018.09.033
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The JETSCAPE collaboration announced the first public release of its framework and Monte Carlo event generator at this conference, providing a unified interface and a comprehensive suite of model implementations for all stages of ultra-relativistic heavy ion collisions. This release focuses on validation of the framework and the $pp$ reference. A full manual is under development. In the mean-time, these proceedings will provide a guide for installation and simulation runs in lieu of the more traditional summary of the presentation.
[ { "created": "Tue, 24 Jul 2018 14:33:29 GMT", "version": "v1" }, { "created": "Mon, 13 Aug 2018 16:56:58 GMT", "version": "v2" } ]
2019-02-20
[ [ "Kauder", "Kolja", "", "for the JETSCAPE Collaboration" ] ]
The JETSCAPE collaboration announced the first public release of its framework and Monte Carlo event generator at this conference, providing a unified interface and a comprehensive suite of model implementations for all stages of ultra-relativistic heavy ion collisions. This release focuses on validation of the framework and the $pp$ reference. A full manual is under development. In the mean-time, these proceedings will provide a guide for installation and simulation runs in lieu of the more traditional summary of the presentation.
hep-ph/9610345
Salman Habib
Fred Cooper, Salman Habib, Yuval Kluger, and Emil Mottola
Nonequilibrium Dynamics of Symmetry Breaking in Lambda Phi^4 Field Theory
32 pages (21 figures), RevTeX (plus macro), uses epsf
Phys.Rev. D55 (1997) 6471-6503
10.1103/PhysRevD.55.6471
LA-UR-96-3336
hep-ph
null
The time evolution of O(N) symmetric lambda Phi^4 scalar field theory is studied in the large N limit. In this limit the <Phi> mean field and two-point correlation function <Phi Phi> evolve together as a self-consistent closed Hamiltonian system, characterized by a Gaussian density matrix. The static part of the effective Hamiltonian defines the True Effective Potential U_eff for configurations far from thermal equilibrium. Numerically solving the time evolution equations for energy densities corresponding to a quench in the unstable spinodal region, we find results quite different from what might be inferred from the equilibrium free energy ``effective'' potential F. Typical time evolutions show effectively irreversible energy flow from the coherent mean fields to the quantum fluctuating modes, due to the creation of massless Goldstone bosons near threshold. The plasma frequency and collisionless damping rate of the mean fields are calculated in terms of the particle number density by a linear response analysis and compared with the numerical results. Dephasing of the fluctuations leads also to the growth of an effective entropy and the transition from quantum to classical behavior of the ensemble. In addition to casting some light on fundamental issues of nonequilibrium quantum statistical mechanics, the general framework presented in this work may be applied to a study of the dynamics of second order phase transitions in a wide variety of Landau-Ginsburg systems described by a scalar order parameter.
[ { "created": "Mon, 14 Oct 1996 09:06:24 GMT", "version": "v1" } ]
2016-09-06
[ [ "Cooper", "Fred", "" ], [ "Habib", "Salman", "" ], [ "Kluger", "Yuval", "" ], [ "Mottola", "Emil", "" ] ]
The time evolution of O(N) symmetric lambda Phi^4 scalar field theory is studied in the large N limit. In this limit the <Phi> mean field and two-point correlation function <Phi Phi> evolve together as a self-consistent closed Hamiltonian system, characterized by a Gaussian density matrix. The static part of the effective Hamiltonian defines the True Effective Potential U_eff for configurations far from thermal equilibrium. Numerically solving the time evolution equations for energy densities corresponding to a quench in the unstable spinodal region, we find results quite different from what might be inferred from the equilibrium free energy ``effective'' potential F. Typical time evolutions show effectively irreversible energy flow from the coherent mean fields to the quantum fluctuating modes, due to the creation of massless Goldstone bosons near threshold. The plasma frequency and collisionless damping rate of the mean fields are calculated in terms of the particle number density by a linear response analysis and compared with the numerical results. Dephasing of the fluctuations leads also to the growth of an effective entropy and the transition from quantum to classical behavior of the ensemble. In addition to casting some light on fundamental issues of nonequilibrium quantum statistical mechanics, the general framework presented in this work may be applied to a study of the dynamics of second order phase transitions in a wide variety of Landau-Ginsburg systems described by a scalar order parameter.
hep-ph/0106011
Igor Sokalski
I.A.Sokalski, E.V.Bugaev, S.I.Klimushin (Institute for Nuclear Research, Russian Academy of Science, Moscow)
MUM: flexible precise algorithm for the muon propagation
Contribution to the 27th ICRC (Hamburg, August 7-15, 2001), 4 pages, 5 .eps figures, uses icrc.cls
null
null
null
hep-ph
null
We present a new muon propagation Monte Carlo FORTRAN code MUM (MUons+Medium) which possesses some advantages over analogous codes presently in use. The most important features of the algorithm are described. Data on the test for algorithm accuracy are presented. Contributions of different sources to the resulting error of simulation are considered. Selected results obtained with MUM are given and compared with ones from other codes.
[ { "created": "Fri, 1 Jun 2001 13:11:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sokalski", "I. A.", "", "Institute for Nuclear\n Research, Russian Academy of Science, Moscow" ], [ "Bugaev", "E. V.", "", "Institute for Nuclear\n Research, Russian Academy of Science, Moscow" ], [ "Klimushin", "S. I.", "", "Institute for Nuclear\n Research, Russian Academy of Science, Moscow" ] ]
We present a new muon propagation Monte Carlo FORTRAN code MUM (MUons+Medium) which possesses some advantages over analogous codes presently in use. The most important features of the algorithm are described. Data on the test for algorithm accuracy are presented. Contributions of different sources to the resulting error of simulation are considered. Selected results obtained with MUM are given and compared with ones from other codes.
hep-ph/0210057
Carsten Van de Bruck
Ph. Brax, C. van de Bruck, A.-C. Davis and C.S. Rhodes
Varying Constants in Brane World Scenarios
5 pages, LaTeX, 5 figures; based on a talk given by C. van de Bruck at JENAM 2002, Porto; typos corrected
Astrophys.Space Sci. 283 (2003) 627-632
10.1023/A:1022543206870
DAMTP-2002-118; T02/118
hep-ph gr-qc hep-th
null
Higher-dimensional theories imply that some constants, such as the gravitational constant and the strength of the gauge-couplings, are not fundamental constants. Instead they are related to the sizes of the extra--dimensional space, which are moduli fields in the four--dimensional effective theory. We study the cosmological evolution of the moduli fields appearing in brane world scenarios and discuss the implications for varying constants.
[ { "created": "Thu, 3 Oct 2002 13:24:19 GMT", "version": "v1" }, { "created": "Fri, 4 Oct 2002 14:05:26 GMT", "version": "v2" } ]
2009-11-07
[ [ "Brax", "Ph.", "" ], [ "van de Bruck", "C.", "" ], [ "Davis", "A. -C.", "" ], [ "Rhodes", "C. S.", "" ] ]
Higher-dimensional theories imply that some constants, such as the gravitational constant and the strength of the gauge-couplings, are not fundamental constants. Instead they are related to the sizes of the extra--dimensional space, which are moduli fields in the four--dimensional effective theory. We study the cosmological evolution of the moduli fields appearing in brane world scenarios and discuss the implications for varying constants.
0911.3865
Wolfgang Bietenholz
Wolfgang Bietenholz
On the Isomorphic Description of Chiral Symmetry Breaking by Non-Unitary Lie Groups
18 pages, to appear in Int. J. Mod. Phys. A
Int.J.Mod.Phys.A25:1699-1712,2010
10.1142/S0217751X10048123
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well-known that chiral symmetry breaking ($\chi$SB) in QCD with $N_{f}=2$ light quark flavours can be described by orthogonal groups as $O(4) \to O(3)$, due to local isomorphisms. Here we discuss the question how specific this property is. We consider generalised forms of $\chi$SB involving an arbitrary number of light flavours of continuum or lattice fermions, in various representations. We search systematically for isomorphic descriptions by non-unitary, compact Lie groups. It turns out that there are a few alternative options in terms of orthogonal groups, while we did not find any description entirely based on symplectic or exceptional Lie groups. If we adapt such an alternative as the symmetry breaking pattern for a generalised Higgs mechanism, we may consider a Higgs particle composed of bound fermions and trace back the mass generation to $\chi$SB. In fact, some of the patterns that we encounter appear in technicolour models. In particular if one observes a Higgs mechanism that can be expressed in terms of orthogonal groups, we specify in which cases it could also represent some kind of $\chi$SB of techniquarks.
[ { "created": "Thu, 19 Nov 2009 18:41:24 GMT", "version": "v1" } ]
2010-04-22
[ [ "Bietenholz", "Wolfgang", "" ] ]
It is well-known that chiral symmetry breaking ($\chi$SB) in QCD with $N_{f}=2$ light quark flavours can be described by orthogonal groups as $O(4) \to O(3)$, due to local isomorphisms. Here we discuss the question how specific this property is. We consider generalised forms of $\chi$SB involving an arbitrary number of light flavours of continuum or lattice fermions, in various representations. We search systematically for isomorphic descriptions by non-unitary, compact Lie groups. It turns out that there are a few alternative options in terms of orthogonal groups, while we did not find any description entirely based on symplectic or exceptional Lie groups. If we adapt such an alternative as the symmetry breaking pattern for a generalised Higgs mechanism, we may consider a Higgs particle composed of bound fermions and trace back the mass generation to $\chi$SB. In fact, some of the patterns that we encounter appear in technicolour models. In particular if one observes a Higgs mechanism that can be expressed in terms of orthogonal groups, we specify in which cases it could also represent some kind of $\chi$SB of techniquarks.
2008.09116
Alexis Plascencia
Pavel Fileviez Perez, Alexis D. Plascencia
Electric Dipole Moments, New Forces and Dark Matter
9 pages, 10 figures. v2: Minor changes to the text, accepted for publication in JHEP
JHEP 03 (2021) 185
10.1007/JHEP03(2021)185
null
hep-ph hep-ex hep-th
http://creativecommons.org/licenses/by/4.0/
New sources of CP violation beyond the Standard Model are crucial to explain the baryon asymmetry in the Universe. We discuss the impact of new CP violating interactions in theories where a dark matter candidate is predicted by the cancellation of gauge anomalies. In these theories, the constraint on the dark matter relic density implies an upper bound on the new symmetry breaking scale from which all new states acquire their masses. We investigate in detail the predictions for electric dipole moments and show that if the relevant CP-violating phase is large, experiments such as the ACME collaboration will be able to fully probe the theory.
[ { "created": "Thu, 20 Aug 2020 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 17 Feb 2021 21:27:19 GMT", "version": "v2" } ]
2021-03-24
[ [ "Perez", "Pavel Fileviez", "" ], [ "Plascencia", "Alexis D.", "" ] ]
New sources of CP violation beyond the Standard Model are crucial to explain the baryon asymmetry in the Universe. We discuss the impact of new CP violating interactions in theories where a dark matter candidate is predicted by the cancellation of gauge anomalies. In these theories, the constraint on the dark matter relic density implies an upper bound on the new symmetry breaking scale from which all new states acquire their masses. We investigate in detail the predictions for electric dipole moments and show that if the relevant CP-violating phase is large, experiments such as the ACME collaboration will be able to fully probe the theory.
hep-ph/9810534
Luc Marleau
B. Dion, T. Gregoire, D. London, L. Marleau and H. Nadeau
Bilepton Production at Hadron Colliders
20 pages (LATEX), 7 figures, minor modifications
Phys.Rev. D59 (1999) 075006
10.1103/PhysRevD.59.075006
LAVAL-PHY-98-12, UdeM-GPP-TH-98-53, McGill-98/26
hep-ph
null
We examine, as model-independently as possible, the production of bileptons at hadron colliders. When a particular model is necessary or useful, we choose the 3-3-1 model. We consider a variety of processes: q anti-q -> Y^{++} Y^{--}, u anti-d -> Y^{++} Y^{-}, anti-u d -> Y^+ Y^{--}, q anti-q -> Y^{++} e^{-} e^{-}, q anti-q -> phi^{++} phi^{--}, u anti-d -> -> phi^{++} phi^{-}, and anti-u d -> phi^{+} phi^{--}, where Y and phi are vector and scalar bileptons, respectively. Given the present low-energy constraints, we find that at the Tevatron, vector bileptons are unobservable, while light scalar bileptons (M_phi <= 300 GeV) are just barely observable. At the LHC, the reach is extended considerably: vector bileptons of mass M_Y <= 1 TeV are observable, as are scalar bileptons of mass M_phi <= 850 GeV.
[ { "created": "Thu, 29 Oct 1998 18:34:03 GMT", "version": "v1" }, { "created": "Fri, 27 Nov 1998 14:24:33 GMT", "version": "v2" } ]
2009-10-31
[ [ "Dion", "B.", "" ], [ "Gregoire", "T.", "" ], [ "London", "D.", "" ], [ "Marleau", "L.", "" ], [ "Nadeau", "H.", "" ] ]
We examine, as model-independently as possible, the production of bileptons at hadron colliders. When a particular model is necessary or useful, we choose the 3-3-1 model. We consider a variety of processes: q anti-q -> Y^{++} Y^{--}, u anti-d -> Y^{++} Y^{-}, anti-u d -> Y^+ Y^{--}, q anti-q -> Y^{++} e^{-} e^{-}, q anti-q -> phi^{++} phi^{--}, u anti-d -> -> phi^{++} phi^{-}, and anti-u d -> phi^{+} phi^{--}, where Y and phi are vector and scalar bileptons, respectively. Given the present low-energy constraints, we find that at the Tevatron, vector bileptons are unobservable, while light scalar bileptons (M_phi <= 300 GeV) are just barely observable. At the LHC, the reach is extended considerably: vector bileptons of mass M_Y <= 1 TeV are observable, as are scalar bileptons of mass M_phi <= 850 GeV.
hep-ph/0011071
Shro Oleg Ivanovich
A. F. Krutov, O. I. Shro and V. E. Troitsky
Isgur--Wise function in a relativistic model of constituent quarks
10 pages, latex, 1 figure as eps-file
Phys.Lett.B502:140-146,2001
10.1016/S0370-2693(00)01377-0
null
hep-ph
null
The integral representation for Isgur -- Wise function (IWF) is obtained in the framework of instant--form relativistic Hamiltonian dynamics for mesons with one heavy quark. The upper and lower limits are calculated for the slope parameter of IWF $\rho^2$ by the model independent way. IWF is calculated for different wave functions of quarks in the meson. The difference between the limits of $\rho^2$ equals 1/3. The constraint on the slope parameter is in a good agreement with experiments. The weak dependence of IWF on the choice of wave functions is found.
[ { "created": "Mon, 6 Nov 2000 10:26:16 GMT", "version": "v1" }, { "created": "Wed, 8 Nov 2000 07:56:23 GMT", "version": "v2" } ]
2014-11-17
[ [ "Krutov", "A. F.", "" ], [ "Shro", "O. I.", "" ], [ "Troitsky", "V. E.", "" ] ]
The integral representation for Isgur -- Wise function (IWF) is obtained in the framework of instant--form relativistic Hamiltonian dynamics for mesons with one heavy quark. The upper and lower limits are calculated for the slope parameter of IWF $\rho^2$ by the model independent way. IWF is calculated for different wave functions of quarks in the meson. The difference between the limits of $\rho^2$ equals 1/3. The constraint on the slope parameter is in a good agreement with experiments. The weak dependence of IWF on the choice of wave functions is found.
hep-ph/0607011
Pierpaolo Mastrolia
Pierpaolo Mastrolia
Unitarity Cuts: NLO Six-Gluon Amplitudes in QCD
talk given at Loops & Legs 2006, April 23-28, Eisenach (Germany)
null
10.1016/j.nuclphysbps.2006.09.046
null
hep-ph
null
We report on a technique for evaluating finite unitarity cut for one-loop amplitudes in gauge theories, and discuss its application to the cut-constructible part of six-gluon amplitude in QCD.
[ { "created": "Sun, 2 Jul 2006 10:56:10 GMT", "version": "v1" } ]
2009-11-11
[ [ "Mastrolia", "Pierpaolo", "" ] ]
We report on a technique for evaluating finite unitarity cut for one-loop amplitudes in gauge theories, and discuss its application to the cut-constructible part of six-gluon amplitude in QCD.
0908.3319
Miguel Sanchis
Miguel-Angel Sanchis-Lozano
Signatures of (Un)particles from a Hidden Sector in multiparticle dynamics at Tevatron/LHC
4 pages, 2 figs, Talk given at SUSY09, Northeastern University, Boston June 2009
AIP Conf.Proc.1200:774-777,2010
10.1063/1.3327727
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of multiparticle dynamics in hadron-hadron collisions at Tevatron and LHC could provide useful information on new physics in addition to the expected signatures on the transverse plane. We suggest that an analysis of inclusive correlations between emitted particles in $pp$ inelastic collisions, and factorial moments of multiplicity distributions, may be helpful in uncovering (un)particles from Hidden Sectors, using underlying events tagged by hard products like high $p_T$ leptons and photons, and applying stringent selection criteria like event shape variables, etc
[ { "created": "Sun, 23 Aug 2009 17:43:37 GMT", "version": "v1" } ]
2015-05-14
[ [ "Sanchis-Lozano", "Miguel-Angel", "" ] ]
The study of multiparticle dynamics in hadron-hadron collisions at Tevatron and LHC could provide useful information on new physics in addition to the expected signatures on the transverse plane. We suggest that an analysis of inclusive correlations between emitted particles in $pp$ inelastic collisions, and factorial moments of multiplicity distributions, may be helpful in uncovering (un)particles from Hidden Sectors, using underlying events tagged by hard products like high $p_T$ leptons and photons, and applying stringent selection criteria like event shape variables, etc
1912.13313
Konstantin Stankevich
Konstantin Stankevich, Alexander Studenikin
The effect of neutrino quantum decoherence
Proceedings of European Physical Society Conference on High Energy Physics - EPS-HEP2019, 10-17 July, 2019. Submitted to Proceedings of Science. arXiv admin note: text overlap with arXiv:1912.13311
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutrino oscillation patterns can be modified by neutrino interactions with external environments including electromagnetic fields that can influence on neutrinos in the case neutrinos have nonzero electromagnetic properties [1]. The phenomenon of neutrino oscillations can proceed only in the case of the coherent superposition of neutrino mass states. An external environment can modify a neutrino evolution in a way that conditions for the coherent superposition of neutrino mass states are violated. Such a violation is called quantum decoherence of neutrino states and leads to the suppression of flavor neutrino oscillations [2, 3]. Note that neutrino decoherence appeared due to the wave separation of different mass states is usually not related to quantum neutrino decoherence, the effect that is not considered below. We consider the neutrino quantum decoherence due to neutrino radiative decay in the presence of an electron medium and radiation field. The corresponding damping of neutrino oscillations is calculated.
[ { "created": "Tue, 31 Dec 2019 14:24:02 GMT", "version": "v1" } ]
2020-01-01
[ [ "Stankevich", "Konstantin", "" ], [ "Studenikin", "Alexander", "" ] ]
The neutrino oscillation patterns can be modified by neutrino interactions with external environments including electromagnetic fields that can influence on neutrinos in the case neutrinos have nonzero electromagnetic properties [1]. The phenomenon of neutrino oscillations can proceed only in the case of the coherent superposition of neutrino mass states. An external environment can modify a neutrino evolution in a way that conditions for the coherent superposition of neutrino mass states are violated. Such a violation is called quantum decoherence of neutrino states and leads to the suppression of flavor neutrino oscillations [2, 3]. Note that neutrino decoherence appeared due to the wave separation of different mass states is usually not related to quantum neutrino decoherence, the effect that is not considered below. We consider the neutrino quantum decoherence due to neutrino radiative decay in the presence of an electron medium and radiation field. The corresponding damping of neutrino oscillations is calculated.
hep-ph/0001097
Krutenkova Anna
A.B.Kaidalov and A.P.Krutenkova (ITEP, Moscow)
On Importance of Inelastic Rescatterings in Pion Double Charge Exchange on Nuclei
25 pages, 13 figures, LaTeX style files cernart.sty and crna12.sty
null
null
null
hep-ph
null
Different aspects of the Gribov--Glauber approach for calculation of inclusive pion double charge exchange (DCX) on nuclei are investigated. Recently we have shown that inelastic rescatterings (IR) with two (and more) pions in the intermediate states give an important contribution to the process of DCX at energies above $\sim0.6 GeV$. In this paper we use the one pion exchange model to study in details amplitudes of two pion production. This allows us to verify theoretical assumptions made in the previous paper and to predict cross section for the forward inclusive pion DCX at energies $\ga1 GeV$, where IR dominate over the conventional DCX mechanism of two sequential single charge exchanges.
[ { "created": "Wed, 12 Jan 2000 16:40:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kaidalov", "A. B.", "", "ITEP, Moscow" ], [ "Krutenkova", "A. P.", "", "ITEP, Moscow" ] ]
Different aspects of the Gribov--Glauber approach for calculation of inclusive pion double charge exchange (DCX) on nuclei are investigated. Recently we have shown that inelastic rescatterings (IR) with two (and more) pions in the intermediate states give an important contribution to the process of DCX at energies above $\sim0.6 GeV$. In this paper we use the one pion exchange model to study in details amplitudes of two pion production. This allows us to verify theoretical assumptions made in the previous paper and to predict cross section for the forward inclusive pion DCX at energies $\ga1 GeV$, where IR dominate over the conventional DCX mechanism of two sequential single charge exchanges.
0907.2527
Ulrich Langenfeld
U. Langenfeld, S. Moch, and P. Uwer
New results for t bar t production at hadron colliders
5 pages, 9 figures, to appear in the proceedings of the XVII International Workshop on Deep-Inelastic Scattering and Related Subjects, DIS 2009, 26-30 April 2009, Madrid
null
null
DESY-09-104, SFB/CPP-09-61, HU-EP-09/31
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present new theoretical predictions for the t bar t production cross section at NNLO at the Tevatron and the LHC. We discuss the scale uncertainty and the errors due to the parton distribution functions (PDFs). For the LHC, we present a fit formula for the pair production cross section as a function of the center of mass energy and we provide predictions for the pair production cross section of a hypothetical heavy fourth generation quark t'.
[ { "created": "Wed, 15 Jul 2009 08:40:48 GMT", "version": "v1" } ]
2009-07-16
[ [ "Langenfeld", "U.", "" ], [ "Moch", "S.", "" ], [ "Uwer", "P.", "" ] ]
We present new theoretical predictions for the t bar t production cross section at NNLO at the Tevatron and the LHC. We discuss the scale uncertainty and the errors due to the parton distribution functions (PDFs). For the LHC, we present a fit formula for the pair production cross section as a function of the center of mass energy and we provide predictions for the pair production cross section of a hypothetical heavy fourth generation quark t'.
hep-ph/9310321
null
V.Barone, M.Genovese, N.N.Nikolaev, E.Predazzi and B.G.Zakharov
Shadowing in deuterium and the small--$x$ limit of $F_2^n/F_2^p$ and $F_2^p - F_2^n$
6 pages, latex, DFTT-93-61
Phys.Lett. B321 (1994) 137-139
10.1016/0370-2693(94)90339-5
null
hep-ph
null
We discuss the updated NMC determination of $F_2^n/F_2^p$ and $F_2^p - F_2^n$. Shadowing effects in deuterium make the structure functions determined by the NMC sensibly different from the true ones in the low--$x$ region. We show that the departure of $F_2^n/F_2^p$ and $F_2^p-F_2^n$ from the Regge expectations at small $x$ observed by the NMC likely disappears if one takes into account the shadowing corrections.
[ { "created": "Wed, 20 Oct 1993 16:50:20 GMT", "version": "v1" } ]
2009-10-22
[ [ "Barone", "V.", "" ], [ "Genovese", "M.", "" ], [ "Nikolaev", "N. N.", "" ], [ "Predazzi", "E.", "" ], [ "Zakharov", "B. G.", "" ] ]
We discuss the updated NMC determination of $F_2^n/F_2^p$ and $F_2^p - F_2^n$. Shadowing effects in deuterium make the structure functions determined by the NMC sensibly different from the true ones in the low--$x$ region. We show that the departure of $F_2^n/F_2^p$ and $F_2^p-F_2^n$ from the Regge expectations at small $x$ observed by the NMC likely disappears if one takes into account the shadowing corrections.
hep-ph/9809540
Mercedes Fatas
Angel Morales (University of Zaragoza)
Review on Double Beta Decay Experiments and Comparison with Theory
12 pages, 9 figures. To be published in Neutrino 98 Conference Proceedings, Nucl. Phys. B (Proc. Suppl.). Ed. by Y. Suzuki and Y. Totsuka
Nucl.Phys.Proc.Suppl. 77 (1999) 335-345
10.1016/S0920-5632(99)00440-5
null
hep-ph
null
The current situation of the double beta decay direct counting experiments is briefly reviewed. A comparison with the theoretical predictions in some representative nuclear models is presented.
[ { "created": "Fri, 25 Sep 1998 17:28:57 GMT", "version": "v1" } ]
2009-10-31
[ [ "Morales", "Angel", "", "University of Zaragoza" ] ]
The current situation of the double beta decay direct counting experiments is briefly reviewed. A comparison with the theoretical predictions in some representative nuclear models is presented.
hep-ph/0204197
Stanley J. Brodsky
Stanley J. Brodsky (SLAC)
Physics Opportunities at a Photon-Photon Collider
Invited Talk presented at the 4th International Workshop On Electron-Electron Interactions at TeV Energies (E- E- 01), University of California, Santa Cruz, CA, 7-9 December 2001
Int.J.Mod.Phys.A18:2871-2892,2003
10.1142/S0217751X03016343
SLAC-PUB-9197
hep-ph
null
The advent of back-scattered laser beams for electron-positron colliders will allow detailed studies of a large array of high energy photon-photon and photon-electron collision processes with polarized beams. These include tests of electroweak theory in photon-photon annihilation such as $\gamma \gamma \to W^+ W^-$, $\gamma \gamma \to $ Higgs bosons, and higher-order loop processes, such as $\gamma \gamma \to \gamma \gamma, Z \gamma, H^0 Z^0$ and $Z Z.$ Methods for measuring the anomalous magnetic and quadrupole moments of the $W$ and $Z$ gauge bosons to high precision in polarized electron-photon and photon-photon collisions are discussed. Since each photon can be resolved into a $W^+ W^-$ pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying $W W$ collisions and annihilation. I also review high energy $\gamma \gamma$ and $e \gamma$ tests of quantum chromodynamics, including the production of two gluon jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes which are also important for the analysis of exclusive semi-leptonic and two-body hadronic B-decays.
[ { "created": "Tue, 16 Apr 2002 22:21:36 GMT", "version": "v1" } ]
2009-09-11
[ [ "Brodsky", "Stanley J.", "", "SLAC" ] ]
The advent of back-scattered laser beams for electron-positron colliders will allow detailed studies of a large array of high energy photon-photon and photon-electron collision processes with polarized beams. These include tests of electroweak theory in photon-photon annihilation such as $\gamma \gamma \to W^+ W^-$, $\gamma \gamma \to $ Higgs bosons, and higher-order loop processes, such as $\gamma \gamma \to \gamma \gamma, Z \gamma, H^0 Z^0$ and $Z Z.$ Methods for measuring the anomalous magnetic and quadrupole moments of the $W$ and $Z$ gauge bosons to high precision in polarized electron-photon and photon-photon collisions are discussed. Since each photon can be resolved into a $W^+ W^-$ pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying $W W$ collisions and annihilation. I also review high energy $\gamma \gamma$ and $e \gamma$ tests of quantum chromodynamics, including the production of two gluon jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes which are also important for the analysis of exclusive semi-leptonic and two-body hadronic B-decays.
1805.06832
Abhishek Iyer M
Abhishek M. Iyer
$B$ anomalies: From warped models to colliders
4 Pages, 2 Figures. Contributions to the proceedings for Rencontres de Moriond, QCD and High energy interactions 2018
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the anomalies in the semi leptonic decays of $B$ mesons in a warped custodial framework. Two possible solutions of lepton non-universality are discussed: A) The muon singlets couple non-universally to NP and B) The non-universality is in the coupling of lepton doublets. Both these scenarios are characterized by different predictions for rare Kaon decays. An essential feature of these scenarios is that the electron contribution to the Wilson coefficients (WC) is non-vanishing, thereby offering possibilities for different patterns of solutions. Beginning with a generic $Z'$ model, we demonstrate how the observation of the ratio $N_{\mu\mu}/N_{ee}$ can be mapped to a given pattern of WC which satisfy the anomalies.
[ { "created": "Thu, 17 May 2018 15:51:13 GMT", "version": "v1" } ]
2018-05-18
[ [ "Iyer", "Abhishek M.", "" ] ]
We address the anomalies in the semi leptonic decays of $B$ mesons in a warped custodial framework. Two possible solutions of lepton non-universality are discussed: A) The muon singlets couple non-universally to NP and B) The non-universality is in the coupling of lepton doublets. Both these scenarios are characterized by different predictions for rare Kaon decays. An essential feature of these scenarios is that the electron contribution to the Wilson coefficients (WC) is non-vanishing, thereby offering possibilities for different patterns of solutions. Beginning with a generic $Z'$ model, we demonstrate how the observation of the ratio $N_{\mu\mu}/N_{ee}$ can be mapped to a given pattern of WC which satisfy the anomalies.
hep-ph/0203016
Adnan Bashir
A. Bashir, A. Huet and A. Raya (U. of Michoacan)
Gauge Dependence of Mass and Condensate in Chirally Asymmetric Phase of Quenched QED3
14 pages, 11 figures, uses revtex
Phys.Rev.D66:025029,2002
10.1103/PhysRevD.66.025029
null
hep-ph
null
We study three dimensional quenched Quantum Electrodynamics in the bare vertex approximation. We investigate the gauge dependence of the dynamically generated Euclidean mass of the fermion and the chiral condensate for a wide range of values of the covariant gauge parameter $\xi$. We find that (i) away from $\xi=0$, gauge dependence of the said quantities is considerably reduced without resorting to sophisticated vertex {\em ansatze}, (ii) wavefunction renormalization plays an important role in restoring gauge invariance and (iii) the Ward-Green-Takahashi identity seems to increase the gauge dependence when used in conjunction with some simplifying assumptions. In the Landau gauge, we also verify that our results are in agreement with those based upon dimensional regularization scheme within the numerical accuracy available.
[ { "created": "Sat, 2 Mar 2002 00:28:22 GMT", "version": "v1" } ]
2009-08-11
[ [ "Bashir", "A.", "", "U. of Michoacan" ], [ "Huet", "A.", "", "U. of Michoacan" ], [ "Raya", "A.", "", "U. of Michoacan" ] ]
We study three dimensional quenched Quantum Electrodynamics in the bare vertex approximation. We investigate the gauge dependence of the dynamically generated Euclidean mass of the fermion and the chiral condensate for a wide range of values of the covariant gauge parameter $\xi$. We find that (i) away from $\xi=0$, gauge dependence of the said quantities is considerably reduced without resorting to sophisticated vertex {\em ansatze}, (ii) wavefunction renormalization plays an important role in restoring gauge invariance and (iii) the Ward-Green-Takahashi identity seems to increase the gauge dependence when used in conjunction with some simplifying assumptions. In the Landau gauge, we also verify that our results are in agreement with those based upon dimensional regularization scheme within the numerical accuracy available.
hep-ph/9709352
Kirill Melnikov
Dmitri Ivanov and Kirill Melnikov
Lepton pair production by a high energy photon in a strong electromagnetic field
20 pages, Latex, 2 Figures
Phys.Rev. D57 (1998) 4025-4034
10.1103/PhysRevD.57.4025
TTP96-35, NTZ-24/97
hep-ph
null
Using impact-factor representation, we consider the lepton pair production by an incident high-energy photon in a strong electromagnetic field of a nucleus. By summing leading terms of perturbation series, we obtain a simple formula for the amplitude, valid to all orders in ${\cal O}(\alpha Z)$ and arbitrary field of the nucleus. Using these results, we derive, in a simple manner, the results for the lepton pair production by a virtual incident photon in a Coulomb field. For real incident photon our results coincide with the known ones. Also, a particular example of a non-Coulomb potential is discussed in some detail.
[ { "created": "Mon, 15 Sep 1997 18:13:22 GMT", "version": "v1" } ]
2009-10-30
[ [ "Ivanov", "Dmitri", "" ], [ "Melnikov", "Kirill", "" ] ]
Using impact-factor representation, we consider the lepton pair production by an incident high-energy photon in a strong electromagnetic field of a nucleus. By summing leading terms of perturbation series, we obtain a simple formula for the amplitude, valid to all orders in ${\cal O}(\alpha Z)$ and arbitrary field of the nucleus. Using these results, we derive, in a simple manner, the results for the lepton pair production by a virtual incident photon in a Coulomb field. For real incident photon our results coincide with the known ones. Also, a particular example of a non-Coulomb potential is discussed in some detail.
2307.05425
Sean Carroll
George B. Field and Sean M. Carroll
Axions and Cosmic Magnetic Fields
null
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that if axions are the dark matter, their coupling to electromagnetism results in exponential growth of a helical magnetic field when the axion field first rolls down its potential. After an inverse cascade, the relevant length scales to day are of order 10-100 kpc, of astrophysical interest. Our mechanism for allowing the field to grow relies on a nuance of MHD. Faraday's Law says that an electric field is needed to create a magnetic field. Previous authors relied on conventional Ohm's law to calculate E, but the resistivity is negligible and therefore they assume E is as well. We use a modified Ohm's Law that includes the effects of self-induction in limiting the current driven by a given E, which allows a magnetic field to grow.
[ { "created": "Tue, 11 Jul 2023 16:47:41 GMT", "version": "v1" }, { "created": "Fri, 14 Jul 2023 18:14:05 GMT", "version": "v2" } ]
2023-07-18
[ [ "Field", "George B.", "" ], [ "Carroll", "Sean M.", "" ] ]
We argue that if axions are the dark matter, their coupling to electromagnetism results in exponential growth of a helical magnetic field when the axion field first rolls down its potential. After an inverse cascade, the relevant length scales to day are of order 10-100 kpc, of astrophysical interest. Our mechanism for allowing the field to grow relies on a nuance of MHD. Faraday's Law says that an electric field is needed to create a magnetic field. Previous authors relied on conventional Ohm's law to calculate E, but the resistivity is negligible and therefore they assume E is as well. We use a modified Ohm's Law that includes the effects of self-induction in limiting the current driven by a given E, which allows a magnetic field to grow.
hep-ph/9905379
Misha Kalmykov
J.Fleischer, M.Yu.Kalmykov, A.V.Kotikov
Recursion relations for two-loop self-energy diagrams on-shell
Talk given by J.Fleischer at 6th International Workshop on Software Engineering, Artificial Intelligence, Neural Nets, Genetic Algorithms, Symbolic Algebra, Automatic Calculation (AIHENP 99), Heraklion, Crete, Greece, 12-16 April, 1999; 8 pages, LaTeX, 3 eps-figures
null
null
null
hep-ph
null
A set of recurrence relations for on-shell two-loop self-energy diagrams with one mass is presented, which allows to reduce the diagrams with arbitrary indices (powers of scalar propagators) to a set of the master integrals. The SHELL2 package is used for the calculation of special types of diagrams. A method of calculation of higher order \epsilon-expansion of master integrals is demonstrated.
[ { "created": "Tue, 18 May 1999 10:23:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fleischer", "J.", "" ], [ "Kalmykov", "M. Yu.", "" ], [ "Kotikov", "A. V.", "" ] ]
A set of recurrence relations for on-shell two-loop self-energy diagrams with one mass is presented, which allows to reduce the diagrams with arbitrary indices (powers of scalar propagators) to a set of the master integrals. The SHELL2 package is used for the calculation of special types of diagrams. A method of calculation of higher order \epsilon-expansion of master integrals is demonstrated.
hep-ph/9808346
Eric S. Swanson
P.R. Page (LANL), E.S. Swanson (NCSU), and A.P. Szczepaniak (IUB)
Hybrid Meson Decay Phenomenology
37 pages, 2 figures, 6 tables, Revtex
Phys.Rev.D59:034016,1999
10.1103/PhysRevD.59.034016
null
hep-ph
null
The phenomenology of a newly developed model of hybrid meson decay is developed. The decay mechanism is based on the heavy quark expansion of QCD and the strong coupling flux tube picture of nonperturbative glue. A comprehensive list of partial decay widths of a wide variety of light, $s\bar s$, $c\bar c$, and $b \bar b$ hybrid mesons is presented. Results which appear approximately universal are highlighted along with those which distinguish different hybrid decay models. Finally, we examine several interesting hybrid candidates in detail.
[ { "created": "Mon, 17 Aug 1998 18:47:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Page", "P. R.", "", "LANL" ], [ "Swanson", "E. S.", "", "NCSU" ], [ "Szczepaniak", "A. P.", "", "IUB" ] ]
The phenomenology of a newly developed model of hybrid meson decay is developed. The decay mechanism is based on the heavy quark expansion of QCD and the strong coupling flux tube picture of nonperturbative glue. A comprehensive list of partial decay widths of a wide variety of light, $s\bar s$, $c\bar c$, and $b \bar b$ hybrid mesons is presented. Results which appear approximately universal are highlighted along with those which distinguish different hybrid decay models. Finally, we examine several interesting hybrid candidates in detail.
hep-ph/9512326
null
Hilmar Forkel (ECT*, Trento, Italy)
Strangeness in the Nucleon: The Strange Vector Form Factors
12 pages (LaTeX), 2 postscript figures, to appear in Prog. Part. Nucl. Phys. 36 (1996)
Prog.Part.Nucl.Phys. 36 (1996) 229-238
10.1016/0146-6410(96)00027-0
ECT*/Dec/95-004
hep-ph nucl-th
null
We discuss two descriptions of the nucleon's strange vector form factors in the framework of vector meson dominance. The first, an updated and extended version of Jaffe's dispersion analysis, approximates the spectral functions of the form factors as a sum of vector meson poles, whereas the second combines vector meson dominance in the $\omega$ and $\phi$ meson sector with an intrinsic strangeness distribution from a kaon cloud. (Plenary talk given at the International School for Nuclear Physics, 17th Course: Quarks and Hadrons in Nuclei, Erice, Sicily, Sept 19-27, 1995.)
[ { "created": "Mon, 18 Dec 1995 04:30:46 GMT", "version": "v1" } ]
2009-10-28
[ [ "Forkel", "Hilmar", "", "ECT*, Trento, Italy" ] ]
We discuss two descriptions of the nucleon's strange vector form factors in the framework of vector meson dominance. The first, an updated and extended version of Jaffe's dispersion analysis, approximates the spectral functions of the form factors as a sum of vector meson poles, whereas the second combines vector meson dominance in the $\omega$ and $\phi$ meson sector with an intrinsic strangeness distribution from a kaon cloud. (Plenary talk given at the International School for Nuclear Physics, 17th Course: Quarks and Hadrons in Nuclei, Erice, Sicily, Sept 19-27, 1995.)
hep-ph/0605257
Hans-Ulrich Martyn
H.-U. Martyn
Detecting metastable staus and gravitinos at the ILC
13 pages, 5 figures
Eur.Phys.J.C48:15-24,2006
10.1140/epjc/s2006-02630-7
DESY 06-075
hep-ph
null
A study of various SUSY scenarios is presented in which the lightest supersymmetric particle is the gravitino $\sG$ and the next-to-lightest supersymmetric particle is a scalar tau $\stau$ with lifetimes ranging from seconds to years. Gravitinos are interesting dark matter candidates which can be produced in decays of heavier sparticles at the International Linear Collider (ILC), but remain undetected in direct searches of astrophysical experiments. We investigate the detection and measurement of metastable staus, which may be copiously produced at the ILC either directly or via cascade decays. A proper choice of the experimental conditions will allow one to stop large samples of staus in the calorimeters of the ILC detector and to study the subsequent decays $\stau\to\tau\sG$. Detailed simulations show that the properties of the stau and the gravitino, such as stau mass and lifetime and gravitino mass, can be accurately determined at a future ILC and may provide direct access to the gravitational coupling, respectively Planck scale.
[ { "created": "Wed, 24 May 2006 12:55:30 GMT", "version": "v1" } ]
2009-01-07
[ [ "Martyn", "H. -U.", "" ] ]
A study of various SUSY scenarios is presented in which the lightest supersymmetric particle is the gravitino $\sG$ and the next-to-lightest supersymmetric particle is a scalar tau $\stau$ with lifetimes ranging from seconds to years. Gravitinos are interesting dark matter candidates which can be produced in decays of heavier sparticles at the International Linear Collider (ILC), but remain undetected in direct searches of astrophysical experiments. We investigate the detection and measurement of metastable staus, which may be copiously produced at the ILC either directly or via cascade decays. A proper choice of the experimental conditions will allow one to stop large samples of staus in the calorimeters of the ILC detector and to study the subsequent decays $\stau\to\tau\sG$. Detailed simulations show that the properties of the stau and the gravitino, such as stau mass and lifetime and gravitino mass, can be accurately determined at a future ILC and may provide direct access to the gravitational coupling, respectively Planck scale.
1405.4706
Diego Aristizabal
D. Aristizabal Sierra, M. Tortola, J. W. F. Valle, A. Vicente
Leptogenesis with a dynamical seesaw scale
16 pages, 7 figures. V2: few clarifications and references added. Matches published version in JCAP
JCAP07(2014)052
10.1088/1475-7516/2014/07/052
IFIC/14-33
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the simplest type-I seesaw leptogenesis scenario right-handed neutrino annihilation processes are absent. However, in the presence of new interactions these processes are possible and can affect the resulting $B-L$ asymmetry in an important way. A prominent example is provided by models with spontaneous lepton number violation, where the existence of new dynamical degrees of freedom can play a crucial role. In this context, we provide a model-independent discussion of the effects of right-handed neutrino annihilations. We show that in the weak washout regime, as long as the scattering processes remain slow compared with the Hubble expansion rate throughout the relevant temperature range, the efficiency can be largely enhanced, reaching in some cases maximal values. Moreover, the $B-L$ asymmetry yield turns out to be independent upon initial conditions, in contrast to the "standard" case. On the other hand, when the annihilation processes are fast, the right-handed neutrino distribution tends to a thermal one down to low temperatures, implying a drastic suppression of the efficiency which in some cases can render the $B-L$ generation mechanism inoperative.
[ { "created": "Mon, 19 May 2014 13:03:03 GMT", "version": "v1" }, { "created": "Thu, 31 Jul 2014 09:51:42 GMT", "version": "v2" } ]
2014-08-01
[ [ "Sierra", "D. Aristizabal", "" ], [ "Tortola", "M.", "" ], [ "Valle", "J. W. F.", "" ], [ "Vicente", "A.", "" ] ]
In the simplest type-I seesaw leptogenesis scenario right-handed neutrino annihilation processes are absent. However, in the presence of new interactions these processes are possible and can affect the resulting $B-L$ asymmetry in an important way. A prominent example is provided by models with spontaneous lepton number violation, where the existence of new dynamical degrees of freedom can play a crucial role. In this context, we provide a model-independent discussion of the effects of right-handed neutrino annihilations. We show that in the weak washout regime, as long as the scattering processes remain slow compared with the Hubble expansion rate throughout the relevant temperature range, the efficiency can be largely enhanced, reaching in some cases maximal values. Moreover, the $B-L$ asymmetry yield turns out to be independent upon initial conditions, in contrast to the "standard" case. On the other hand, when the annihilation processes are fast, the right-handed neutrino distribution tends to a thermal one down to low temperatures, implying a drastic suppression of the efficiency which in some cases can render the $B-L$ generation mechanism inoperative.
hep-ph/0102246
Jeonghyeon Song
Chun Liu (ITP, Beijing) and Jeonghyeon Song (KIAS)
A Model for Neutrino Warm Dark Matter and Neutrino Oscillations
11 pages, Final version to appear in PLB, References added
Phys.Lett. B512 (2001) 247-251
10.1016/S0370-2693(01)00730-4
ASITP-2001-002 and KIAS-P01007
hep-ph
null
The muon- and tau-neutrinos with the mass in the keV range, which are allowed in a low reheating temperature cosmology, can compose the warm dark matter of the universe. A model of four light neutrinos including the keV scale $\nu_\mu$ and $\nu_\tau$ is studied, which combines the seesaw mechanism and the Abelian flavor symmetry. The atmospheric neutrino anomaly is due to the $\nu_\mu-\nu_\tau$ oscillation. The solar neutrino problem is answered by the oscillation into the light sterile neutrino, where the SMA, LMA, and LOW-QVO solutions can be accommodated in our scenario.
[ { "created": "Tue, 20 Feb 2001 06:13:16 GMT", "version": "v1" }, { "created": "Wed, 21 Feb 2001 00:32:27 GMT", "version": "v2" }, { "created": "Thu, 7 Jun 2001 01:42:13 GMT", "version": "v3" } ]
2009-11-07
[ [ "Liu", "Chun", "", "ITP, Beijing" ], [ "Song", "Jeonghyeon", "", "KIAS" ] ]
The muon- and tau-neutrinos with the mass in the keV range, which are allowed in a low reheating temperature cosmology, can compose the warm dark matter of the universe. A model of four light neutrinos including the keV scale $\nu_\mu$ and $\nu_\tau$ is studied, which combines the seesaw mechanism and the Abelian flavor symmetry. The atmospheric neutrino anomaly is due to the $\nu_\mu-\nu_\tau$ oscillation. The solar neutrino problem is answered by the oscillation into the light sterile neutrino, where the SMA, LMA, and LOW-QVO solutions can be accommodated in our scenario.
hep-ph/0009201
Maria Krawczyk
Maria Krawczyk (Institute of Theoretical Physics, University of Warsaw, Poland), Jan Zochowski (Bialystok University, Poland) and Peter Mattig (Weizmann Institute, Rehovot, Israel)
The light Higgs window in the 2HDM at GigaZ
Latex file, 11 pages, 6 ps figures
Eur.Phys.J.C19:463-469,2001
10.1007/s100520100585
IFT-2000-22
hep-ph
null
The sensitivity to a light Higgs boson in the general 2HDM (II), with a mass below 40 GeV, is estimated for an future e+e- linear collider operating with very high luminosity at the Z peak (GigaZ). We consider a possible Higgs boson production via the Bjorken process, the (hA) pair production, the Yukawa process Z -> b {\bar b} h(A), -> tau {\bar tau} h(A), and the decay Z ->h(A)+gamma. Although the discovery potential is considerably extended compared to the current sensitivities, mainly from LEP, the existence of a h or A even with a mass of a few GeV cannot be excluded with two billion Z decays. The need to study the very light Higgs scenario at a linear e+e- collider running at several hundred GeV and the LHC is emphasised.
[ { "created": "Sun, 17 Sep 2000 15:04:29 GMT", "version": "v1" } ]
2009-01-07
[ [ "Krawczyk", "Maria", "", "Institute of Theoretical Physics, University of\n Warsaw, Poland" ], [ "Zochowski", "Jan", "", "Bialystok University, Poland" ], [ "Mattig", "Peter", "", "Weizmann Institute, Rehovot, Israel" ] ]
The sensitivity to a light Higgs boson in the general 2HDM (II), with a mass below 40 GeV, is estimated for an future e+e- linear collider operating with very high luminosity at the Z peak (GigaZ). We consider a possible Higgs boson production via the Bjorken process, the (hA) pair production, the Yukawa process Z -> b {\bar b} h(A), -> tau {\bar tau} h(A), and the decay Z ->h(A)+gamma. Although the discovery potential is considerably extended compared to the current sensitivities, mainly from LEP, the existence of a h or A even with a mass of a few GeV cannot be excluded with two billion Z decays. The need to study the very light Higgs scenario at a linear e+e- collider running at several hundred GeV and the LHC is emphasised.
1903.04151
Laurent Schoeffel
C. Baldenegro, S. Hassani, C. Royon, L. Schoeffel
Extending the constraint for axion-like particles as resonances at the LHC and laser beam experiments
23 pages, 4 figures, 1 table
Phys Lett B, PLB34704, 2019
10.1016/j.physletb.2019.06.029
null
hep-ph physics.optics
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the discovery potential of axion-like particles (ALP), pseudo-scalars weakly coupled to Standard Model fields, at the Large Hadron Collider (LHC). Our focus is on ALPs coupled to the electromagnetic field, which would induce anomalous scattering of light-by-light. This can be directly probed in central exclusive production of photon pairs in ultra-peripheral collisions at the LHC in proton and heavy ion collisions. We consider non-standard collision modes of the LHC, such as argon-argon collisions at $\sqrt{s_{NN}} = 7$ TeV and proton-lead collisions at $\sqrt{s_{NN}} = 8.16$ TeV to access regions in the parameter space complementary to the ones previously considered for lead-lead or proton-proton collisions. In addition, we show that, using laser beam interactions, we can constrain ALPs as resonant deviations in the refractive index, induced by anomalous light-by-light scattering effects. If we combine the aforementioned approaches, ALPs can be probed in a wide range of masses from the eV scale up to the TeV scale.
[ { "created": "Mon, 11 Mar 2019 07:36:22 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2019 15:42:00 GMT", "version": "v2" }, { "created": "Mon, 17 Jun 2019 19:44:06 GMT", "version": "v3" }, { "created": "Wed, 19 Jun 2019 07:14:04 GMT", "version": "v4" } ]
2019-06-20
[ [ "Baldenegro", "C.", "" ], [ "Hassani", "S.", "" ], [ "Royon", "C.", "" ], [ "Schoeffel", "L.", "" ] ]
We study the discovery potential of axion-like particles (ALP), pseudo-scalars weakly coupled to Standard Model fields, at the Large Hadron Collider (LHC). Our focus is on ALPs coupled to the electromagnetic field, which would induce anomalous scattering of light-by-light. This can be directly probed in central exclusive production of photon pairs in ultra-peripheral collisions at the LHC in proton and heavy ion collisions. We consider non-standard collision modes of the LHC, such as argon-argon collisions at $\sqrt{s_{NN}} = 7$ TeV and proton-lead collisions at $\sqrt{s_{NN}} = 8.16$ TeV to access regions in the parameter space complementary to the ones previously considered for lead-lead or proton-proton collisions. In addition, we show that, using laser beam interactions, we can constrain ALPs as resonant deviations in the refractive index, induced by anomalous light-by-light scattering effects. If we combine the aforementioned approaches, ALPs can be probed in a wide range of masses from the eV scale up to the TeV scale.
hep-ph/0202229
Alexander D. Smirnov
A.D. Smirnov (Yaroslavl State University, Russia)
Bounds on scalar leptoquark and scalar gluon masses from S, T, U in the minimal four color symmetry model
14 pages, 2 figures, to appear in Physics Letters B
Phys.Lett. B531 (2002) 237-244
10.1016/S0370-2693(02)01432-6
YARU-HE-02/01
hep-ph
null
The contributions into radiative correction parameters S, T, U from scalar leptoquark and scalar gluon doublets are investigated in the minimal four color symmetry model. It is shown that the current experimental data on S, T, U allow the scalar leptoquarks and the scalar gluons to be relatively light (with masses of order of 1 TeV or less), the lightest particles are preferred to lie below 400 GeV. In particular, the lightest scalar leptoquarks with masses below 300 GeV are shown to be compatible with the current data on S, T, U at $\chi^2 < 3.1 (3.2)$ for $m_H = 115 (300) GeV$ in comparison with $\chi^2 = 3.5 (5.0)$ in the Standard Model. The lightest scalar gluon in this case is expected to lie below 850 (720) GeV. The possible significance of such particles in the t-quark physics at LHC is emphasized.
[ { "created": "Mon, 25 Feb 2002 14:05:38 GMT", "version": "v1" } ]
2009-11-07
[ [ "Smirnov", "A. D.", "", "Yaroslavl State University, Russia" ] ]
The contributions into radiative correction parameters S, T, U from scalar leptoquark and scalar gluon doublets are investigated in the minimal four color symmetry model. It is shown that the current experimental data on S, T, U allow the scalar leptoquarks and the scalar gluons to be relatively light (with masses of order of 1 TeV or less), the lightest particles are preferred to lie below 400 GeV. In particular, the lightest scalar leptoquarks with masses below 300 GeV are shown to be compatible with the current data on S, T, U at $\chi^2 < 3.1 (3.2)$ for $m_H = 115 (300) GeV$ in comparison with $\chi^2 = 3.5 (5.0)$ in the Standard Model. The lightest scalar gluon in this case is expected to lie below 850 (720) GeV. The possible significance of such particles in the t-quark physics at LHC is emphasized.
2107.03025
Jason Evans
John Ellis, Jason L. Evans, Natsumi Nagata, Dimitri V. Nanopoulos and Keith A. Olive
Flipped $g_\mu-2$
17 pages, 5 figures
null
10.1140/epjc/s10052-021-09829-8
KCL-PH-TH/2021-46,CERN-TH-2021-099, ACT-1-21, MI-HET-751, UMN-TH-4018/21, FTPI-MINN-21/11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the possible magnitude of the supersymmetric contribution to $g_\mu - 2$ in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and the soft supersymmetry-breaking masses of right-handed sleptons are unrelated to the other gaugino, slepton and squark masses. Consequently, the lightest neutralino and the right-handed smuon may be light enough to mitigate the discrepancy between the experimental measurement of $g_\mu - 2$ and the Standard Model calculation, in which case they may be detectable at the LHC and/or a 250 GeV $e^+ e^-$ collider, whereas the other gauginos and sfermions are heavy enough to escape detection at the LHC.
[ { "created": "Wed, 7 Jul 2021 05:47:53 GMT", "version": "v1" } ]
2021-12-22
[ [ "Ellis", "John", "" ], [ "Evans", "Jason L.", "" ], [ "Nagata", "Natsumi", "" ], [ "Nanopoulos", "Dimitri V.", "" ], [ "Olive", "Keith A.", "" ] ]
We analyze the possible magnitude of the supersymmetric contribution to $g_\mu - 2$ in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and the soft supersymmetry-breaking masses of right-handed sleptons are unrelated to the other gaugino, slepton and squark masses. Consequently, the lightest neutralino and the right-handed smuon may be light enough to mitigate the discrepancy between the experimental measurement of $g_\mu - 2$ and the Standard Model calculation, in which case they may be detectable at the LHC and/or a 250 GeV $e^+ e^-$ collider, whereas the other gauginos and sfermions are heavy enough to escape detection at the LHC.
hep-ph/0701073
Sergo Gerasimov
S.B. Gerasimov (Dubna, JINR)
Dispersion total photoproduction sum rules for nucleons and few-body nuclei revisited
8 pages, Latex; The report presented at Advanced Studies Institute: Symmetries and Spin (SPIN-Praha-2006), Prague, Czech Republic, 19-26 Jul 2006
Czech.J.Phys.56:F195-F201,2006
null
null
hep-ph
null
The questions on the presense and quantitative role of the constant terms in the real part of the high-energy photon-nucleon and photon-nucleus amplitudes representing the contribution of the non-Regge (the fixed j=0-pole) singularities in the finite-energy sum rules (FESR) for the photoabsorption cross sections on nucleons and the lightest atomic nuclei are discussed and new testable relations are presented for relevant combinations of the Compton scattering amplitudes.
[ { "created": "Wed, 10 Jan 2007 09:44:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gerasimov", "S. B.", "", "Dubna, JINR" ] ]
The questions on the presense and quantitative role of the constant terms in the real part of the high-energy photon-nucleon and photon-nucleus amplitudes representing the contribution of the non-Regge (the fixed j=0-pole) singularities in the finite-energy sum rules (FESR) for the photoabsorption cross sections on nucleons and the lightest atomic nuclei are discussed and new testable relations are presented for relevant combinations of the Compton scattering amplitudes.
hep-ph/0607155
Thomas Schwetz
S.T. Petcov, T. Schwetz
Precision measurement of solar neutrino oscillation parameters by a long-baseline reactor neutrino experiment in Europe
16 pages, 6 figures
Phys.Lett.B642:487-494,2006
10.1016/j.physletb.2006.09.063
SISSA 40/2006/EP
hep-ph hep-ex
null
We consider the determination of the solar neutrino oscillation parameters $\Delta m^2_{21}$ and $\theta_{12}$ by studying oscillations of reactor anti-neutrinos emitted by nuclear power plants (located mainly in France) with a detector installed in the Frejus underground laboratory. The performances of a water Cerenkov detector of 147 kt fiducial mass doped with 0.1% of Gadolinium (MEMPHYS-Gd) and of a 50 kt scale liquid scintillator detector (LENA) are compared. In both cases 3$\sigma$ uncertainties below 3% on $\Delta m^2_{21}$ and of about 20% on $\sin^2\theta_{12}$ can be obtained after one year of data taking. The Gadolinium doped Super-Kamiokande detector (SK-Gd) in Japan can reach a similar precision if the SK/MEMPHYS fiducial mass ratio of 1 to 7 is compensated by a longer SK-Gd data taking time. Several years of reactor neutrino data collected by MEMPHYS-Gd or LENA would allow a determination of $\Delta m^2_{21}$ and $\sin^2\theta_{12}$ with uncertainties of approximately 1% and 10% at 3$\sigma$, respectively. These accuracies are comparable to those that can be reached in the measurement of the atmospheric neutrino oscillation parameters $\Delta m^2_{31}$ and $\sin^2\theta_{23}$ in long-baseline superbeam experiments.
[ { "created": "Thu, 13 Jul 2006 16:34:14 GMT", "version": "v1" } ]
2008-11-26
[ [ "Petcov", "S. T.", "" ], [ "Schwetz", "T.", "" ] ]
We consider the determination of the solar neutrino oscillation parameters $\Delta m^2_{21}$ and $\theta_{12}$ by studying oscillations of reactor anti-neutrinos emitted by nuclear power plants (located mainly in France) with a detector installed in the Frejus underground laboratory. The performances of a water Cerenkov detector of 147 kt fiducial mass doped with 0.1% of Gadolinium (MEMPHYS-Gd) and of a 50 kt scale liquid scintillator detector (LENA) are compared. In both cases 3$\sigma$ uncertainties below 3% on $\Delta m^2_{21}$ and of about 20% on $\sin^2\theta_{12}$ can be obtained after one year of data taking. The Gadolinium doped Super-Kamiokande detector (SK-Gd) in Japan can reach a similar precision if the SK/MEMPHYS fiducial mass ratio of 1 to 7 is compensated by a longer SK-Gd data taking time. Several years of reactor neutrino data collected by MEMPHYS-Gd or LENA would allow a determination of $\Delta m^2_{21}$ and $\sin^2\theta_{12}$ with uncertainties of approximately 1% and 10% at 3$\sigma$, respectively. These accuracies are comparable to those that can be reached in the measurement of the atmospheric neutrino oscillation parameters $\Delta m^2_{31}$ and $\sin^2\theta_{23}$ in long-baseline superbeam experiments.
0704.1153
Feng Yuan
Jian-Wei Qiu, Werner Vogelsang, Feng Yuan
Asymmetric Di-jet Production in Polarized Hadronic Collisions
11 pages, 2 figures
Phys.Lett.B650:373-378,2007
10.1016/j.physletb.2007.05.023
BNL-NT-07/15, RBRC-665
hep-ph
null
Using the collinear QCD factorization approach, we study the single-transverse-spin dependent cross section Delta sigma(S_perp) for the hadronic production of two jets of momenta P_1=P+q/2 and P_2=-P+q/2. We consider the kinematic region where the transverse components of the momentum vectors satisfy P_perp >> q_perp >> Lambda_QCD. For the case of initial-state gluon radiation, we show that at the leading power in q_perp/P_perp and at the lowest non-trivial perturbative order, the dependence of Delta sigma(S_perp) on q_perp decouples from that on P_perp, so that the cross section can be factorized into a hard part that is a function only of the single scale P_perp, and into perturbatively generated transverse-momentum dependent (TMD) parton distributions with transverse momenta k_perp = O(q_perp).
[ { "created": "Mon, 9 Apr 2007 22:12:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Qiu", "Jian-Wei", "" ], [ "Vogelsang", "Werner", "" ], [ "Yuan", "Feng", "" ] ]
Using the collinear QCD factorization approach, we study the single-transverse-spin dependent cross section Delta sigma(S_perp) for the hadronic production of two jets of momenta P_1=P+q/2 and P_2=-P+q/2. We consider the kinematic region where the transverse components of the momentum vectors satisfy P_perp >> q_perp >> Lambda_QCD. For the case of initial-state gluon radiation, we show that at the leading power in q_perp/P_perp and at the lowest non-trivial perturbative order, the dependence of Delta sigma(S_perp) on q_perp decouples from that on P_perp, so that the cross section can be factorized into a hard part that is a function only of the single scale P_perp, and into perturbatively generated transverse-momentum dependent (TMD) parton distributions with transverse momenta k_perp = O(q_perp).
hep-ph/0209198
Klaus Werner
K. Werner, H.J. Drescher, S.Ostapchenko, T.Pierog
The Nexus Model
Invited talk given at the International Workshop on the Physics of the Quark Gluon Plasma, Palaiseau, France, September 4-7, 2001
null
null
null
hep-ph
null
The interpretation of experimental results at RHIC and in the future also at LHC requires very reliable and realistic models. Considerable effort has been devoted to the development of such models during the past decade, many of them being heavily used in order to analyze data. There are, however, serious inconsistencies in the above-mentioned approaches. In this paper, we will introduce a fully self-consistent formulation of the multiple-scattering scheme in the framework of a Gribov-Regge type effective theory.
[ { "created": "Wed, 18 Sep 2002 09:09:56 GMT", "version": "v1" } ]
2016-09-06
[ [ "Werner", "K.", "" ], [ "Drescher", "H. J.", "" ], [ "Ostapchenko", "S.", "" ], [ "Pierog", "T.", "" ] ]
The interpretation of experimental results at RHIC and in the future also at LHC requires very reliable and realistic models. Considerable effort has been devoted to the development of such models during the past decade, many of them being heavily used in order to analyze data. There are, however, serious inconsistencies in the above-mentioned approaches. In this paper, we will introduce a fully self-consistent formulation of the multiple-scattering scheme in the framework of a Gribov-Regge type effective theory.
hep-ph/0212027
Pavel Pobylitsa
P. V. Pobylitsa
T-odd quark distributions: QCD versus chiral models
3 pages
null
null
null
hep-ph
null
The T-odd quark distrbutions are shown to vanish in the chiral sigma model in contrast to the opposite widespread opinion. This failure of the chiral sigma model is a feature of the model itself and has nothing to do with the recent progress in the clarification of the status of the T-odd distributions in QCD.
[ { "created": "Mon, 2 Dec 2002 20:48:12 GMT", "version": "v1" }, { "created": "Mon, 23 Dec 2002 14:05:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Pobylitsa", "P. V.", "" ] ]
The T-odd quark distrbutions are shown to vanish in the chiral sigma model in contrast to the opposite widespread opinion. This failure of the chiral sigma model is a feature of the model itself and has nothing to do with the recent progress in the clarification of the status of the T-odd distributions in QCD.
hep-ph/9811280
Juan Carlos Montero
J. C. Montero, V. Pleitez and O. Ravinez (Instituto de Fisica Teorica, IFT-UNESP)
Soft superweak CP violation in a 331 model
REVTEX, 21 pages, 10 eps figures
Phys.Rev. D60 (1999) 076003
10.1103/PhysRevD.60.076003
IFT-P.082/98
hep-ph
null
We show that it is possible to implement soft superweak CP violation in the context of a 331 model with only three triplets. All CP violation effects come from the exchange of singly and doubly charged scalars. We consider the implication of this mechanism in the quark and lepton sectors. In particular it is shown that in this model, as in most of those which incorporate the scalar mediated CP violation, it is possible to have large electric dipole moments for the muon and the tau lepton while keeping small those of the electron and the neutron. The CKM mixing matrix is real up to the two loop level.
[ { "created": "Mon, 9 Nov 1998 18:49:57 GMT", "version": "v1" } ]
2016-09-06
[ [ "Montero", "J. C.", "", "Instituto de Fisica Teorica,\n IFT-UNESP" ], [ "Pleitez", "V.", "", "Instituto de Fisica Teorica,\n IFT-UNESP" ], [ "Ravinez", "O.", "", "Instituto de Fisica Teorica,\n IFT-UNESP" ] ]
We show that it is possible to implement soft superweak CP violation in the context of a 331 model with only three triplets. All CP violation effects come from the exchange of singly and doubly charged scalars. We consider the implication of this mechanism in the quark and lepton sectors. In particular it is shown that in this model, as in most of those which incorporate the scalar mediated CP violation, it is possible to have large electric dipole moments for the muon and the tau lepton while keeping small those of the electron and the neutron. The CKM mixing matrix is real up to the two loop level.
1010.5217
Antonio Pich
Antonio Pich
Flavour constraints on multi-Higgs-doublet models: Yukawa alignment
6 pages, 5 figures. Talk given in the "Third Workshop on Theory, Phenomenology and Experiments in Heavy Flavour Physics" (Capri, 5-7 July 2010)
Nucl.Phys.Proc.Suppl.209:182-187,2010
10.1016/j.nuclphysbps.2010.12.030
IFIC/10-41, FTUV/10-1025
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In multi-Higgs-doublet models, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation. With N Higgs doublets (and no right-handed neutrinos) the Yukawa Lagrangian is characterized by the fermion masses, the CKM quark mixing matrix and 3(N-1) complex couplings. Quantum corrections break the alignment, generating a minimal-flavour-violation structure with flavour-blind phases. The aligned multi-Higgs-doublet models lead to a rich and viable phenomenology with an interesting hierarchy of flavour-changing neutral current effects, suppressing them in light-quark systems while allowing potentially relevant signals in heavy-quark transitions.
[ { "created": "Mon, 25 Oct 2010 18:34:56 GMT", "version": "v1" } ]
2011-04-05
[ [ "Pich", "Antonio", "" ] ]
In multi-Higgs-doublet models, the alignment in flavour space of all Yukawa matrices coupling to a given right-handed fermion guarantees the absence of tree-level flavour-changing neutral couplings, while introducing new sources of CP violation. With N Higgs doublets (and no right-handed neutrinos) the Yukawa Lagrangian is characterized by the fermion masses, the CKM quark mixing matrix and 3(N-1) complex couplings. Quantum corrections break the alignment, generating a minimal-flavour-violation structure with flavour-blind phases. The aligned multi-Higgs-doublet models lead to a rich and viable phenomenology with an interesting hierarchy of flavour-changing neutral current effects, suppressing them in light-quark systems while allowing potentially relevant signals in heavy-quark transitions.
2106.13857
Manoranjan Dutta
Manoranjan Dutta (1), Subhaditya Bhattacharya (2), Purusottam Ghosh (3), Narendra Sahu (1) ((1) Indian Institute of Technology Hyderabad, (2) Indian Institute of Technology Guwahati (3) Harish-Chandra Research Institute, Allahabad)
Majorana Dark Matter and Neutrino mass in a singlet-doublet extension of the Standard Model
DAE-BRNS-HEP symposium 2020 Proccedings
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
A minimal extension of the Standard Model (SM) by a vector-like fermion doublet and three right handed (RH) singlet neutrinos is proposed in order to explain dark matter and tiny neutrino mass simultaneously. The DM arises as a mixture of the neutral component of the fermion doublet and one of the RH neutrinos, both assumed to be odd under an imposed $\mathcal{Z}_2$ symmetry. Being Majorana in nature, the DM escapes from $Z$-mediated direct search constraints to mark a significant difference from singlet-doublet Dirac DM. The other two $\mathcal{Z}_2$ even heavy RH neutrinos give rise masses and mixing of light neutrinos via Type-I Seesaw mechanism. Relic density and direct search allowed parameter space for the model is investigated through detailed numerical scan.
[ { "created": "Fri, 25 Jun 2021 19:31:04 GMT", "version": "v1" } ]
2021-06-29
[ [ "Dutta", "Manoranjan", "" ], [ "Bhattacharya", "Subhaditya", "" ], [ "Ghosh", "Purusottam", "" ], [ "Sahu", "Narendra", "" ] ]
A minimal extension of the Standard Model (SM) by a vector-like fermion doublet and three right handed (RH) singlet neutrinos is proposed in order to explain dark matter and tiny neutrino mass simultaneously. The DM arises as a mixture of the neutral component of the fermion doublet and one of the RH neutrinos, both assumed to be odd under an imposed $\mathcal{Z}_2$ symmetry. Being Majorana in nature, the DM escapes from $Z$-mediated direct search constraints to mark a significant difference from singlet-doublet Dirac DM. The other two $\mathcal{Z}_2$ even heavy RH neutrinos give rise masses and mixing of light neutrinos via Type-I Seesaw mechanism. Relic density and direct search allowed parameter space for the model is investigated through detailed numerical scan.
1207.4861
Gilad Perez
Gian F. Giudice, Gilad Perez, Yotam Soreq
Flavor Beyond the Standard Universe
12 pages, 4 figures
null
null
CERN-PH-TH/2012-202
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility that the observed pattern of quark masses is the consequence of a statistical distribution of Yukawa couplings within the multiverse. We employ the anthropic condition that only two ultra light quarks exist, justifying the observed richness of organic chemistry. Moreover, the mass of the recently discovered Higgs boson suggests that the top Yukawa coupling lies near the critical condition where the electroweak vacuum becomes unstable, leading to a new kind of flavor puzzle and to a new anthropic condition. We scan Yukawa couplings according to distributions motivated by high-scale flavor dynamics and find cases in which our pattern of quark masses has a plausible probability within the multiverse. Finally we show that, under some assumptions, these distributions can significantly ameliorate the runaway behavior leading to weakless universes.
[ { "created": "Fri, 20 Jul 2012 07:14:29 GMT", "version": "v1" } ]
2012-07-23
[ [ "Giudice", "Gian F.", "" ], [ "Perez", "Gilad", "" ], [ "Soreq", "Yotam", "" ] ]
We explore the possibility that the observed pattern of quark masses is the consequence of a statistical distribution of Yukawa couplings within the multiverse. We employ the anthropic condition that only two ultra light quarks exist, justifying the observed richness of organic chemistry. Moreover, the mass of the recently discovered Higgs boson suggests that the top Yukawa coupling lies near the critical condition where the electroweak vacuum becomes unstable, leading to a new kind of flavor puzzle and to a new anthropic condition. We scan Yukawa couplings according to distributions motivated by high-scale flavor dynamics and find cases in which our pattern of quark masses has a plausible probability within the multiverse. Finally we show that, under some assumptions, these distributions can significantly ameliorate the runaway behavior leading to weakless universes.
hep-ph/0005151
Ed Stoeffhaas
D. Zeppenfeld
Measurement of Higgs Properties at the LHC
6 pages, Revtex (singlespaced), uses epsfig.sty, 1 postscript figure. Talk given at the 35th Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, France, March 18-25, 2000
null
null
MADPH-00-1179
hep-ph
null
A SM-like Higgs boson can be produced in a variety of channels at the LHC. By combining information from production via gluon fusion and weak boson fusion, various partial widths and the total Higgs boson width can be extracted. Expected accuracies for 200 fb^{-1} of data are in the 10% range.
[ { "created": "Tue, 16 May 2000 16:31:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zeppenfeld", "D.", "" ] ]
A SM-like Higgs boson can be produced in a variety of channels at the LHC. By combining information from production via gluon fusion and weak boson fusion, various partial widths and the total Higgs boson width can be extracted. Expected accuracies for 200 fb^{-1} of data are in the 10% range.
1403.3970
Carlos Louren\c{c}o
Pietro Faccioli, Valentin Knuenz, Carlos Lourenco, Joao Seixas, Hermine K. Woehri
Quarkonium production in the LHC era: a polarized perspective
Submitted to Phys. Lett. B
null
10.1016/j.physletb.2014.07.006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Polarization measurements are usually considered as the most difficult challenge for the QCD description of quarkonium production. In fact, global data fits for the determination of the non-perturbative parameters of bound-state formation traditionally exclude polarization observables and use them as a posteriori verifications of the predictions, with perplexing results. With a change of perspective, we move polarization data to the centre of the study, advocating that they actually provide the strongest fundamental indications about the production mechanisms, even before we explicitly consider perturbative calculations. Considering psi(2S) and Y(3S) measurements from LHC experiments and state-of-the-art NLO short-distance calculations in the framework of non-relativistic QCD factorization (NRQCD), we perform a search for a kinematic domain where the polarizations can be correctly reproduced together with the cross sections, by systematically scanning the phase space and accurately treating the experimental uncertainties. This strategy provides a straightforward solution to the "quarkonium polarization puzzle" and reassuring signs that the theoretical framework is reliable. At the same time, the results expose unexpected hierarchies in the non-perturbative NRQCD parameters, that open new paths towards the understanding of bound-state formation in QCD.
[ { "created": "Sun, 16 Mar 2014 22:43:23 GMT", "version": "v1" } ]
2015-06-19
[ [ "Faccioli", "Pietro", "" ], [ "Knuenz", "Valentin", "" ], [ "Lourenco", "Carlos", "" ], [ "Seixas", "Joao", "" ], [ "Woehri", "Hermine K.", "" ] ]
Polarization measurements are usually considered as the most difficult challenge for the QCD description of quarkonium production. In fact, global data fits for the determination of the non-perturbative parameters of bound-state formation traditionally exclude polarization observables and use them as a posteriori verifications of the predictions, with perplexing results. With a change of perspective, we move polarization data to the centre of the study, advocating that they actually provide the strongest fundamental indications about the production mechanisms, even before we explicitly consider perturbative calculations. Considering psi(2S) and Y(3S) measurements from LHC experiments and state-of-the-art NLO short-distance calculations in the framework of non-relativistic QCD factorization (NRQCD), we perform a search for a kinematic domain where the polarizations can be correctly reproduced together with the cross sections, by systematically scanning the phase space and accurately treating the experimental uncertainties. This strategy provides a straightforward solution to the "quarkonium polarization puzzle" and reassuring signs that the theoretical framework is reliable. At the same time, the results expose unexpected hierarchies in the non-perturbative NRQCD parameters, that open new paths towards the understanding of bound-state formation in QCD.
hep-ph/0209231
Andreas S. Kronfeld
Andreas S. Kronfeld
Progress in Lattice QCD
Invited talk at the XXII Physics in Collisions Conference (PIC02), Stanford, Ca, USA, June 2002, 15+1 pp. PSN FRBT05
eConfC020620:FRBT05,2002
null
FERMILAB-Conf-02/228-T
hep-ph hep-lat
null
After reviewing some of the mathematical foundations and numerical difficulties facing lattice QCD, I review the status of several calculations relevant to experimental high-energy physics. The topics considered are moments of structure functions, which may prove relevant to search for new phenomena at the LHC, and several aspects of flavor physics, which are relevant to understanding CP and flavor violation.
[ { "created": "Thu, 19 Sep 2002 19:25:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kronfeld", "Andreas S.", "" ] ]
After reviewing some of the mathematical foundations and numerical difficulties facing lattice QCD, I review the status of several calculations relevant to experimental high-energy physics. The topics considered are moments of structure functions, which may prove relevant to search for new phenomena at the LHC, and several aspects of flavor physics, which are relevant to understanding CP and flavor violation.
2203.09407
Paul Caucal
Paul Caucal, Yacine Mehtar-Tani
Universality aspects of quantum corrections to transverse momentum broadening in QCD media
57 pages, 15 figures
null
10.1007/JHEP09(2022)023
null
hep-ph cond-mat.stat-mech nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study non-linear quantum corrections to transverse momentum broadening (TMB) of a fast parton propagating in dense QCD matter in the leading logarithmic approximation. These non-local corrections yield an anomalous super-diffusive behavior characterized by a heavy tailed distribution which is associated with L\'{e}vy random walks. Using a formal analogy with the physics of traveling waves, we show that at late times the transverse momentum distribution tends to a universal scaling regime. We derive analytic solutions in terms of an asymptotic expansion around the scaling limit for both fixed and running coupling. We note that our analytic approach yields a good agreement with the exact numerical solutions down to realistic values of medium length. Finally, we discuss the interplay between system size and energy dependence of the diffusion coefficient $\hat q$ and its connection with the gluon distribution function that is manifest at large transverse momentum transfer.
[ { "created": "Thu, 17 Mar 2022 16:00:44 GMT", "version": "v1" } ]
2022-09-21
[ [ "Caucal", "Paul", "" ], [ "Mehtar-Tani", "Yacine", "" ] ]
We study non-linear quantum corrections to transverse momentum broadening (TMB) of a fast parton propagating in dense QCD matter in the leading logarithmic approximation. These non-local corrections yield an anomalous super-diffusive behavior characterized by a heavy tailed distribution which is associated with L\'{e}vy random walks. Using a formal analogy with the physics of traveling waves, we show that at late times the transverse momentum distribution tends to a universal scaling regime. We derive analytic solutions in terms of an asymptotic expansion around the scaling limit for both fixed and running coupling. We note that our analytic approach yields a good agreement with the exact numerical solutions down to realistic values of medium length. Finally, we discuss the interplay between system size and energy dependence of the diffusion coefficient $\hat q$ and its connection with the gluon distribution function that is manifest at large transverse momentum transfer.
hep-ph/0602087
Wayne W. Repko
Ali Abbasabadi and Wayne W. Repko
Higgs boson decay into Z bosons and a photon
4 pages, 5 figures, RevTeX, figures corrected
JHEP 0608 (2006) 048
10.1088/1126-6708/2006/08/048
null
hep-ph
null
We have performed a one-loop calculation of the width of the rare decay H -> Z Z \gamma in the standard model for Higgs boson masses 190 GeV \leq m_H \leq 250 GeV. We find that the most dominant helicity combinations for the Z bosons and the photon is when one of the Z bosons is longitudinally polarized and the other Z boson and the photon have the same helicity. A comparison of the decay width \Gamma(H->Z Z \gamma) to those of H->\gamma \gamma and H->\gamma Z shows that the ratios of the decay widths are \Gamma(H->Z Z \gamma) / \Gamma(H->\gamma\gamma) ~ \Gamma(H->Z Z \gamma) / \Gamma(H->\gamma Z) ~ 10^{-7}.
[ { "created": "Thu, 9 Feb 2006 21:19:40 GMT", "version": "v1" }, { "created": "Tue, 21 Feb 2006 16:11:34 GMT", "version": "v2" } ]
2009-11-11
[ [ "Abbasabadi", "Ali", "" ], [ "Repko", "Wayne W.", "" ] ]
We have performed a one-loop calculation of the width of the rare decay H -> Z Z \gamma in the standard model for Higgs boson masses 190 GeV \leq m_H \leq 250 GeV. We find that the most dominant helicity combinations for the Z bosons and the photon is when one of the Z bosons is longitudinally polarized and the other Z boson and the photon have the same helicity. A comparison of the decay width \Gamma(H->Z Z \gamma) to those of H->\gamma \gamma and H->\gamma Z shows that the ratios of the decay widths are \Gamma(H->Z Z \gamma) / \Gamma(H->\gamma\gamma) ~ \Gamma(H->Z Z \gamma) / \Gamma(H->\gamma Z) ~ 10^{-7}.
1808.05514
Alexander Kaloshin
A.E. Kaloshin and D.M.Voronin
Neutrino propagation in media and axis of complete polarization
16 pages, journal version
null
10.1140/epjc/s10052-019-6659-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct a spectral representation of neutrino propagator in moving matter or in external magnetic field. In both cases there exists fixed four-dimensional axis of polarization, such that the corresponding spin projectors commute with propagator. As a result, all eigenvalues of propagator and, consequently, dispersion laws for neutrino in media are classified according to spin projection onto this axis. Use of the found spin projectors simplifies essentially the eigenvalue problem and allows to build spectral representation of propagator in moving matter or external magnetic field in analogy with the vacuum propagator.
[ { "created": "Thu, 16 Aug 2018 14:31:38 GMT", "version": "v1" }, { "created": "Sat, 16 Mar 2019 14:40:35 GMT", "version": "v2" } ]
2019-03-27
[ [ "Kaloshin", "A. E.", "" ], [ "Voronin", "D. M.", "" ] ]
We construct a spectral representation of neutrino propagator in moving matter or in external magnetic field. In both cases there exists fixed four-dimensional axis of polarization, such that the corresponding spin projectors commute with propagator. As a result, all eigenvalues of propagator and, consequently, dispersion laws for neutrino in media are classified according to spin projection onto this axis. Use of the found spin projectors simplifies essentially the eigenvalue problem and allows to build spectral representation of propagator in moving matter or external magnetic field in analogy with the vacuum propagator.
hep-ph/9612478
Big Bad Bob
Qaisar Shafi and Robert K. Schaefer, (Bartol Research Institute, University of Delaware)
The Cold Plus Hot Dark Matter Model From Supersymmetric Inflation
13 pages LaTEX, with two postscript figures. To appear in the Proceedings of the Dark Matter '96 meeting in Heldelberg, Germany
null
null
null
hep-ph astro-ph
null
The cold plus hot dark matter (CHDM) model is arguably the best theory we currently have for a consistent description of the observed large scale structure formation. This is especially true if the primordial density fluctuations are assumed to be essentially scale invariant, in which case a mixture with 20-25 % HDM, 5- 10 % baryons, and the rest in CDM correctly predicted (in 1989) the quadrupole anisotropy measured a few years later by the COBE satellite. After a brief historical introduction, we present a model of supersymmetric inflation in which the CHDM model is neatly realized with a spectral index n= 0.98, while the dark matter consists of a few eV `tau' neutrino and the LSP (essentially the `bino'). We also provide a comparison of this model against the observations.
[ { "created": "Fri, 27 Dec 1996 20:53:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Shafi", "Qaisar", "" ], [ "Schaefer", "Robert K.", "" ] ]
The cold plus hot dark matter (CHDM) model is arguably the best theory we currently have for a consistent description of the observed large scale structure formation. This is especially true if the primordial density fluctuations are assumed to be essentially scale invariant, in which case a mixture with 20-25 % HDM, 5- 10 % baryons, and the rest in CDM correctly predicted (in 1989) the quadrupole anisotropy measured a few years later by the COBE satellite. After a brief historical introduction, we present a model of supersymmetric inflation in which the CHDM model is neatly realized with a spectral index n= 0.98, while the dark matter consists of a few eV `tau' neutrino and the LSP (essentially the `bino'). We also provide a comparison of this model against the observations.
hep-ph/0011109
Antonio D. Polosa
N.A. Tornqvist and A.D. Polosa
How can one understand the lightest scalars, especially the sigma
9 pages; Invited plenary talk by N.A. Tornqvist at the ''Biennial Conference on Low Energy Antiproton Physics'' (LEAP2000), Venice, Italy, August 20-26, 2000. To appear in Nucl. Phys. A (proc. suppl.)
Nucl.Phys. A692 (2001) 259-267
10.1016/S0375-9474(01)01185-X
HIP-2000-60/TH
hep-ph
null
We discuss how the a_0(980), f_0(980), K^*_0(1430) and particularly the broad sigma resonance can be understood within a coupled channel framework, which includes all light two-pseudoscalar thresholds together with constraints from Adler zeroes, flavour symmetric couplings, unitarity and physically acceptable analyticity. All (qbar q) scalars are, when unitarized, strongly distorted by hadronic mass shifts, and the nonstrange isoscalar state becomes a very broad resonance, with its pole at 470-i250 MeV. We believe this is the sigma meson required by models for spontaneous breaking of chiral symmetry. Recently this light resonance has clearly been observed in D-> sigma pi-> 3pi by the E791 experiment at Fermilab, and we discuss how this decay channel can be predicted in a Constituent Quark Meson Model (CQM), which incorporates heavy quark and chiral symmetries. We also discuss the less well known phenomenon that with a large coupling there can appear two physical resonance poles on the second sheet although only one bare quark-antiquark state is put in. The f_0(980) and f_0(1370) resonance poles can thus be two manifestations of the same (sbar s) quark state. Both of these states are seen clearly in D_s-> 3pi by the E791 experiment, where (sbar s) intermediate states are expected to be dominant.
[ { "created": "Wed, 8 Nov 2000 13:12:13 GMT", "version": "v1" } ]
2009-10-31
[ [ "Tornqvist", "N. A.", "" ], [ "Polosa", "A. D.", "" ] ]
We discuss how the a_0(980), f_0(980), K^*_0(1430) and particularly the broad sigma resonance can be understood within a coupled channel framework, which includes all light two-pseudoscalar thresholds together with constraints from Adler zeroes, flavour symmetric couplings, unitarity and physically acceptable analyticity. All (qbar q) scalars are, when unitarized, strongly distorted by hadronic mass shifts, and the nonstrange isoscalar state becomes a very broad resonance, with its pole at 470-i250 MeV. We believe this is the sigma meson required by models for spontaneous breaking of chiral symmetry. Recently this light resonance has clearly been observed in D-> sigma pi-> 3pi by the E791 experiment at Fermilab, and we discuss how this decay channel can be predicted in a Constituent Quark Meson Model (CQM), which incorporates heavy quark and chiral symmetries. We also discuss the less well known phenomenon that with a large coupling there can appear two physical resonance poles on the second sheet although only one bare quark-antiquark state is put in. The f_0(980) and f_0(1370) resonance poles can thus be two manifestations of the same (sbar s) quark state. Both of these states are seen clearly in D_s-> 3pi by the E791 experiment, where (sbar s) intermediate states are expected to be dominant.
hep-ph/9211295
Andreas Wirzba
A. Wirzba
Nuclear Matter Aspects of Skyrmions
20 pages, LaTeX, TH Darmstadt: IKDA 92/37
null
null
null
hep-ph nucl-th
null
As an alternative approach to the infinite-array description of dense matter in the Skyrme model, we report about the properties of a single skyrmion on a compact 3-sphere of finite radius. The density of this matter can be increased by decreasing the hypersphere radius. As in the array calculations one encounters a transition to a distinct high density phase characterized by a delocalization in energy and baryon charge and by increased symmetries. We will argue that the high density phase has to be interpreted as chirally restored one. The arguments are based on the formation of complete chiral multiplets and the vanishing of the pionic massless Goldstone modes in the high-density fluctuation spectrum. We show that the restoration of chiral symmetry is common to any chirally invariant extension of the usual Skyrme model - whether via higher-order contact terms or via the introduction of stabilizing vector mesons which act over a finite range. (Talk at the workshop on ``Baryons as Skyrme Solitons'', Siegen, Germany, Sept. 27-30, 1992)
[ { "created": "Mon, 23 Nov 1992 15:10:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Wirzba", "A.", "" ] ]
As an alternative approach to the infinite-array description of dense matter in the Skyrme model, we report about the properties of a single skyrmion on a compact 3-sphere of finite radius. The density of this matter can be increased by decreasing the hypersphere radius. As in the array calculations one encounters a transition to a distinct high density phase characterized by a delocalization in energy and baryon charge and by increased symmetries. We will argue that the high density phase has to be interpreted as chirally restored one. The arguments are based on the formation of complete chiral multiplets and the vanishing of the pionic massless Goldstone modes in the high-density fluctuation spectrum. We show that the restoration of chiral symmetry is common to any chirally invariant extension of the usual Skyrme model - whether via higher-order contact terms or via the introduction of stabilizing vector mesons which act over a finite range. (Talk at the workshop on ``Baryons as Skyrme Solitons'', Siegen, Germany, Sept. 27-30, 1992)
1006.2171
Dilip Kumar Ghosh
Debajyoti Choudhury and Dilip Kumar Ghosh
A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC
18 pages, 9 figures, Figure 1 is modified, more discussions are added in section 2. new references added
JHEP 1102:033,2011
10.1007/JHEP02(2011)033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A fourth chiral generation, with $m_{t^\prime}$ in the range $\sim (300 - 500)$ GeV and a moderate value of the CP-violating phase can explain the anomalous like-sign dimuon charge asymmetry observed recently by the D0 collaboration. The required parameters are found to be consistent with constraints from other $B$ and $K$ decays. The presence of such quarks, apart from being detectable in the early stages of the LHC, would also have important consequences in the electroweak symmetry breaking sector.
[ { "created": "Thu, 10 Jun 2010 23:27:20 GMT", "version": "v1" }, { "created": "Wed, 21 Jul 2010 09:28:46 GMT", "version": "v2" } ]
2011-02-18
[ [ "Choudhury", "Debajyoti", "" ], [ "Ghosh", "Dilip Kumar", "" ] ]
A fourth chiral generation, with $m_{t^\prime}$ in the range $\sim (300 - 500)$ GeV and a moderate value of the CP-violating phase can explain the anomalous like-sign dimuon charge asymmetry observed recently by the D0 collaboration. The required parameters are found to be consistent with constraints from other $B$ and $K$ decays. The presence of such quarks, apart from being detectable in the early stages of the LHC, would also have important consequences in the electroweak symmetry breaking sector.
2009.12220
Roman Gerasimov
V.S. Fadin, R.E. Gerasimov
Parton distributions in radiative corrections to the cross section of electron-proton scattering
arXiv admin note: text overlap with arXiv:1812.10710
null
null
Budker INP 2020-10
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The structure function approach and the parton picture, developed for the theoretical description of the deep inelastic electron-proton scattering, also proved to be very effective for calculation of radiative corrections in Quantum Electrodynamics. We use them to calculate radiative corrections to the cross section of electron-proton scattering due to electron-photon interaction, in the experimental setup with the recoil proton detection, proposed by A.A. Vorobev to measure the proton radius. In the one-loop approximation, explicit expressions for these corrections are obtained for arbitrary momentum transfers. It is shown that, at momentum transfers small compared with the proton mass, various contributions to the corrections mutually cancel each other with power accuracy. In two loops, the corrections are obtained in the leading logarithmic approximation.
[ { "created": "Thu, 24 Sep 2020 07:54:12 GMT", "version": "v1" } ]
2020-09-28
[ [ "Fadin", "V. S.", "" ], [ "Gerasimov", "R. E.", "" ] ]
The structure function approach and the parton picture, developed for the theoretical description of the deep inelastic electron-proton scattering, also proved to be very effective for calculation of radiative corrections in Quantum Electrodynamics. We use them to calculate radiative corrections to the cross section of electron-proton scattering due to electron-photon interaction, in the experimental setup with the recoil proton detection, proposed by A.A. Vorobev to measure the proton radius. In the one-loop approximation, explicit expressions for these corrections are obtained for arbitrary momentum transfers. It is shown that, at momentum transfers small compared with the proton mass, various contributions to the corrections mutually cancel each other with power accuracy. In two loops, the corrections are obtained in the leading logarithmic approximation.
hep-ph/0509345
Shahin Agaev
S. S. Agaev (IPP, Baku State Univ.)
Higher twist distribution amplitudes of the pion and electromagnetic form factor $F_{\pi}(Q^2)$
13 pages, 7 figures; the version to appear in Phys.Rev. D
Phys.Rev. D72 (2005) 074020
10.1103/PhysRevD.72.074020
null
hep-ph
null
The pion electromagnetic form factor is calculated within the QCD light-cone sum rule method and using a renormalon model for the higher twist distribution amplitudes (DAs). The theoretical predictions are compared with the experimental data and constraints on the pion leading and twist-4 DAs are extracted. An upper bound on the twist-4 contribution to the form factor and estimates of effects due to higher conformal spins in the pion twist-4 DAs are obtained.
[ { "created": "Thu, 29 Sep 2005 12:54:37 GMT", "version": "v1" }, { "created": "Thu, 13 Oct 2005 08:34:10 GMT", "version": "v2" } ]
2009-11-11
[ [ "Agaev", "S. S.", "", "IPP, Baku State Univ." ] ]
The pion electromagnetic form factor is calculated within the QCD light-cone sum rule method and using a renormalon model for the higher twist distribution amplitudes (DAs). The theoretical predictions are compared with the experimental data and constraints on the pion leading and twist-4 DAs are extracted. An upper bound on the twist-4 contribution to the form factor and estimates of effects due to higher conformal spins in the pion twist-4 DAs are obtained.
hep-ph/0610051
Manuel Pincetti
M. Pincetti, B. Pasquini, S. Boffi (Pavia U. and INFN, Pavia)
Chiral-Odd Generalized Parton Distributions and Transversity in Light-Front Constituent Quark Models
8 pages, 3 figures. Invited talk at the "Advanced Studies Institute on SYMMETRIES AND SPIN" (SPIN-Praha-2006), 19-26 July, 2006, Prague. To be pubblished in Czechoslovak Journal of Physics. Some references added
Czech.J.Phys.56:F229-F236,2006
null
null
hep-ph
null
We present the general framework to calculate chiral-odd generalized parton distributions in the overlap representation using the Fock-state decomposition in the transverse spin basis. In the forward limit we derive the transversity distribution, the tensor charge and the angular momentum sum rule for quarks with transverse polarization in an unpolarized nucleon. Numerical results are obtained by applying the formalism to the case of light-cone wavefunctions of constituent quark models.
[ { "created": "Wed, 4 Oct 2006 15:31:49 GMT", "version": "v1" }, { "created": "Thu, 5 Oct 2006 09:21:40 GMT", "version": "v2" } ]
2008-11-26
[ [ "Pincetti", "M.", "", "Pavia U. and INFN, Pavia" ], [ "Pasquini", "B.", "", "Pavia U. and INFN, Pavia" ], [ "Boffi", "S.", "", "Pavia U. and INFN, Pavia" ] ]
We present the general framework to calculate chiral-odd generalized parton distributions in the overlap representation using the Fock-state decomposition in the transverse spin basis. In the forward limit we derive the transversity distribution, the tensor charge and the angular momentum sum rule for quarks with transverse polarization in an unpolarized nucleon. Numerical results are obtained by applying the formalism to the case of light-cone wavefunctions of constituent quark models.
hep-ph/9504389
Serguei Khlebnikov
S.Yu. Khlebnikov and R.G. Schnathorst
Strong-coupling expansions for chiral models of electroweak symmetry breaking
11 pages, latex, no figures
Phys.Lett. B358 (1995) 81-86
10.1016/0370-2693(95)00993-U
PURD-TH-95-01
hep-ph
null
We consider chiral $U(N)\times U(N)$ models with fermions in the limit of infinitely large local bare Yukawa coupling. When the scalar field is subject to non-linear constraint, phase transitions in these models are seen to be identical to those in the corresponding purely bosonic ones. Relaxing the non-linear constraint, we compute the seventh-order strong-coupling series for the susceptibility in these models and analyze them numerically for the $U(2)\times U(2)$ case. We find that in four dimensions the approach to the phase transition follows to a good accuracy the mean-field critical behavior, indicating the absence of non-trivial fixed points at strong coupling and being consistent with the first-order nature of the transition. In three dimensions, the strongly-coupled bosonic $U(2)\times U(2)$ model (without gauge fields) has a first-order transition strong enough to accommodate electroweak baryogenesis only for a narrow region of the bare parameter space.
[ { "created": "Tue, 25 Apr 1995 01:56:24 GMT", "version": "v1" } ]
2009-10-28
[ [ "Khlebnikov", "S. Yu.", "" ], [ "Schnathorst", "R. G.", "" ] ]
We consider chiral $U(N)\times U(N)$ models with fermions in the limit of infinitely large local bare Yukawa coupling. When the scalar field is subject to non-linear constraint, phase transitions in these models are seen to be identical to those in the corresponding purely bosonic ones. Relaxing the non-linear constraint, we compute the seventh-order strong-coupling series for the susceptibility in these models and analyze them numerically for the $U(2)\times U(2)$ case. We find that in four dimensions the approach to the phase transition follows to a good accuracy the mean-field critical behavior, indicating the absence of non-trivial fixed points at strong coupling and being consistent with the first-order nature of the transition. In three dimensions, the strongly-coupled bosonic $U(2)\times U(2)$ model (without gauge fields) has a first-order transition strong enough to accommodate electroweak baryogenesis only for a narrow region of the bare parameter space.
hep-ph/0112231
Gudrun Heinrich
M. Fontannaz, J.Ph. Guillet, G. Heinrich
A NLO calculation of the large p_T photon + photon -> photon + jet cross section
23 pages LaTex, 11 figures
Eur.Phys.J.C23:503-511,2002
10.1007/s100520200907
LAPTH-887/01, LPT-Orsay 01-105, IPPP/01/68, DCPT/01/136
hep-ph
null
We study the production of an isolated large p_T photon as well as the production of an isolated prompt photon plus a jet in e^+e^- collisions. Our results are obtained by a NLO Monte Carlo program of partonic event generator type. We discuss the possibilities to constrain the parton densities in the real photon and compare to preliminary OPAL data.
[ { "created": "Mon, 17 Dec 2001 19:50:38 GMT", "version": "v1" } ]
2011-09-13
[ [ "Fontannaz", "M.", "" ], [ "Guillet", "J. Ph.", "" ], [ "Heinrich", "G.", "" ] ]
We study the production of an isolated large p_T photon as well as the production of an isolated prompt photon plus a jet in e^+e^- collisions. Our results are obtained by a NLO Monte Carlo program of partonic event generator type. We discuss the possibilities to constrain the parton densities in the real photon and compare to preliminary OPAL data.
hep-ph/0402157
Toshifumi Yamashita
Naoyuki Haba and Toshifumi Yamashita
Dynamical symmetry breaking in Gauge-Higgs unification of 5D ${\mathcal N}=1$ SUSY theory
15 pages, 4 figures;disscutions on Higgs quartic couplings added
JHEP 0404:016,2004
10.1088/1126-6708/2004/04/016
KUNS-1895
hep-ph
null
We study the dynamical symmetry breaking in the gauge-Higgs unification of the 5D ${\mathcal N}=1$ SUSY theory, compactified on an orbifold, $S^1/Z_2$. This theory identifies Wilson line degrees of freedoms as ``Higgs doublets''. We consider $SU(3)_c \times SU(3)_W$ and SU(6) models, in which the gauge symmetries are reduced to $SU(3)_c \times SU(2)_L \times U(1)_Y$ and $SU(3)_c \times SU(2)_L \times U(1)_Y \times U(1)$, respectively, through the orbifolding boundary conditions. Quarks and leptons are bulk fields, so that Yukawa interactions can be derived from the 5D gauge interactions. We estimate the one loop effective potential of ``Higgs doublets'', and analyze the vacuum structures in these two models. We find that the effects of bulk quarks and leptons destabilize the suitable electro-weak vacuum. We show that the introduction of suitable numbers of extra bulk fields possessing the suitable representations can realize the appropriate electro-weak symmetry breaking.
[ { "created": "Sun, 15 Feb 2004 08:31:48 GMT", "version": "v1" }, { "created": "Thu, 25 Mar 2004 14:10:24 GMT", "version": "v2" } ]
2010-11-19
[ [ "Haba", "Naoyuki", "" ], [ "Yamashita", "Toshifumi", "" ] ]
We study the dynamical symmetry breaking in the gauge-Higgs unification of the 5D ${\mathcal N}=1$ SUSY theory, compactified on an orbifold, $S^1/Z_2$. This theory identifies Wilson line degrees of freedoms as ``Higgs doublets''. We consider $SU(3)_c \times SU(3)_W$ and SU(6) models, in which the gauge symmetries are reduced to $SU(3)_c \times SU(2)_L \times U(1)_Y$ and $SU(3)_c \times SU(2)_L \times U(1)_Y \times U(1)$, respectively, through the orbifolding boundary conditions. Quarks and leptons are bulk fields, so that Yukawa interactions can be derived from the 5D gauge interactions. We estimate the one loop effective potential of ``Higgs doublets'', and analyze the vacuum structures in these two models. We find that the effects of bulk quarks and leptons destabilize the suitable electro-weak vacuum. We show that the introduction of suitable numbers of extra bulk fields possessing the suitable representations can realize the appropriate electro-weak symmetry breaking.
1210.2603
Rathin Adhikari
Zini Rahman, Arnab Dasgupta, Rathin Adhikari
Non-standard interaction effect on $CP$ violation in neutrino oscillation with super-beam
21 pages, 8 figures(39 eps files), text, figures modified
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have studied the $CP$ violation discovery reach in neutrino oscillation experiment with superbeam in presence of non-standard interactions of neutrinos with matter for both short and long baselines. For the most important channel of oscillation ($\nu_\mu \rightarrow \nu_e$) for $CP$ violation discovery there is significant effect in the oscillation probability particularly due to NSIs' $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ for longer baseline and higher energy in comparison to other NSIs'. Interestingly for these two NSIs' (for real and higher allowed values) there is possibility of better discovery reach of $CP$ violation than that with only Standard Model interactions of neutrinos with matter provided that NSI values are known. For complex NSIs' we have shown the $CP$ violation discovery reach in the plane of Dirac phase $\delta$ and NSI phase $\phi_{ij}$. Our analysis indicates that for some values of some NSI phases total $CP$ violation may not be observable for any values of $\delta $.
[ { "created": "Tue, 9 Oct 2012 14:08:18 GMT", "version": "v1" }, { "created": "Mon, 28 Jan 2013 12:00:11 GMT", "version": "v2" }, { "created": "Mon, 21 Apr 2014 11:57:02 GMT", "version": "v3" } ]
2014-04-22
[ [ "Rahman", "Zini", "" ], [ "Dasgupta", "Arnab", "" ], [ "Adhikari", "Rathin", "" ] ]
We have studied the $CP$ violation discovery reach in neutrino oscillation experiment with superbeam in presence of non-standard interactions of neutrinos with matter for both short and long baselines. For the most important channel of oscillation ($\nu_\mu \rightarrow \nu_e$) for $CP$ violation discovery there is significant effect in the oscillation probability particularly due to NSIs' $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ for longer baseline and higher energy in comparison to other NSIs'. Interestingly for these two NSIs' (for real and higher allowed values) there is possibility of better discovery reach of $CP$ violation than that with only Standard Model interactions of neutrinos with matter provided that NSI values are known. For complex NSIs' we have shown the $CP$ violation discovery reach in the plane of Dirac phase $\delta$ and NSI phase $\phi_{ij}$. Our analysis indicates that for some values of some NSI phases total $CP$ violation may not be observable for any values of $\delta $.
hep-ph/9703229
Pedro Bicudo
P. Bicudo (Centro de Fisica das Interacoes fundamentais, Instituto Superior Tecnico, Lisboa)
Spontaneous Chiral Symmetry Breaking Beyond BCS
4 pages in latex revtex, 0 Postscript figures
null
null
FISIST/5-97/CFIF
hep-ph
null
At the BCS level of chiral symmetry breaking, the mass gap equation for quark-antiquark condensation only uses the kernel of the Bethe-Salpeter equation. We introduce coupled channels with ladder mesons in the mass gap equation. Consistency is insured by the Ward Identity for axial currents, and the $\pi$ remains a Goldstone boson in the chiral limit. We find that bare mesons with confined quarks do not contribute to the mass gap equation, and estimate that the contribution of full mesons may be large.
[ { "created": "Tue, 4 Mar 1997 14:23:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bicudo", "P.", "", "Centro de Fisica das Interacoes fundamentais, Instituto\n Superior Tecnico, Lisboa" ] ]
At the BCS level of chiral symmetry breaking, the mass gap equation for quark-antiquark condensation only uses the kernel of the Bethe-Salpeter equation. We introduce coupled channels with ladder mesons in the mass gap equation. Consistency is insured by the Ward Identity for axial currents, and the $\pi$ remains a Goldstone boson in the chiral limit. We find that bare mesons with confined quarks do not contribute to the mass gap equation, and estimate that the contribution of full mesons may be large.
1512.02091
Florian Domingo
Florian Domingo (IFCA / IFT)
Update of the flavour-physics constraints in the NMSSM
22 pages, 7 figures
null
10.1140/epjc/s10052-016-4298-z
IFT-UAM/CSIC-15-130
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the impact of several flavour-changing observables in the $B$- and the Kaon sectors on the parameter space of the NMSSM, in a minimal flavour violating version of this model. Our purpose consists in updating our previous results in arXiv:0710.3714 and designing an up-to-date flavour test for the public package NMSSMTools. We provide details concerning our implementation of the constraints in a series of brief reviews of the current status of the considered channels. Finally, we present a few consequences of these flavour constraints for the NMSSM, turning to two specific scenarios: one is characteristic of the MSSM-limit and illustrates the workings of charged-Higgs and genuinely supersymmetric contributions to flavour-changing processes; the second focus is a region where a light CP-odd Higgs is present. Strong limits are found whenever an enhancement factor - large $\tan\beta$, light $H^{\pm}$, resonant pseudoscalar - comes into play.
[ { "created": "Mon, 7 Dec 2015 15:34:21 GMT", "version": "v1" } ]
2016-09-21
[ [ "Domingo", "Florian", "", "IFCA / IFT" ] ]
We consider the impact of several flavour-changing observables in the $B$- and the Kaon sectors on the parameter space of the NMSSM, in a minimal flavour violating version of this model. Our purpose consists in updating our previous results in arXiv:0710.3714 and designing an up-to-date flavour test for the public package NMSSMTools. We provide details concerning our implementation of the constraints in a series of brief reviews of the current status of the considered channels. Finally, we present a few consequences of these flavour constraints for the NMSSM, turning to two specific scenarios: one is characteristic of the MSSM-limit and illustrates the workings of charged-Higgs and genuinely supersymmetric contributions to flavour-changing processes; the second focus is a region where a light CP-odd Higgs is present. Strong limits are found whenever an enhancement factor - large $\tan\beta$, light $H^{\pm}$, resonant pseudoscalar - comes into play.
hep-ph/9907506
Masahide Yamaguchi
Masahide Yamaguchi
Scaling Property of the global string in the radiation dominated universe
18 pages, 9 figures, to appear in Phys. Rev. D
Phys.Rev. D60 (1999) 103511
10.1103/PhysRevD.60.103511
null
hep-ph astro-ph
null
We investigate the evolution of the global string network in the radiation dominated universe by use of numerical simulations in 3+1 dimensions. We find that the global string network settles down to the scaling regime where the energy density of global strings, $\rho_{s}$, is given by $\rho_{s} = \xi \mu / t^2$ with $\mu$ the string tension per unit length and the scaling parameter, $\xi \sim (0.9-1.3)$, irrespective of the cosmic time. We also find that the loop distribution function can be fitted with that predicted by the so-called one scale model. Concretely, the number density, $n_{l}(t)$, of the loop with the length, $l$, is given by $n_{l}(t) = \nu/[t^{3/2} (l + \kappa t)^{5/2}]$ where $\nu \sim 0.0865$ and $\kappa$ is related with the Nambu-Goldstone(NG) boson radiation power from global strings, $P$, as $P = \kappa \mu$ with $\kappa \sim 0.535$. Therefore, the loop production function also scales and the typical scale of produced loops is nearly the horizon distance. Thus, the evolution of the global string network in the radiation dominated universe can be well described by the one scale model in contrast with that of the local string network.
[ { "created": "Tue, 27 Jul 1999 01:41:04 GMT", "version": "v1" } ]
2016-09-06
[ [ "Yamaguchi", "Masahide", "" ] ]
We investigate the evolution of the global string network in the radiation dominated universe by use of numerical simulations in 3+1 dimensions. We find that the global string network settles down to the scaling regime where the energy density of global strings, $\rho_{s}$, is given by $\rho_{s} = \xi \mu / t^2$ with $\mu$ the string tension per unit length and the scaling parameter, $\xi \sim (0.9-1.3)$, irrespective of the cosmic time. We also find that the loop distribution function can be fitted with that predicted by the so-called one scale model. Concretely, the number density, $n_{l}(t)$, of the loop with the length, $l$, is given by $n_{l}(t) = \nu/[t^{3/2} (l + \kappa t)^{5/2}]$ where $\nu \sim 0.0865$ and $\kappa$ is related with the Nambu-Goldstone(NG) boson radiation power from global strings, $P$, as $P = \kappa \mu$ with $\kappa \sim 0.535$. Therefore, the loop production function also scales and the typical scale of produced loops is nearly the horizon distance. Thus, the evolution of the global string network in the radiation dominated universe can be well described by the one scale model in contrast with that of the local string network.
hep-ph/0702203
Vladimir Zykunov
Vladimir A. Zykunov
Electroweak corrections to the Drell-Yan process in the high dimuon mass range
Changed content; 11 pp, 5 fig
null
null
null
hep-ph
null
The complete electroweak radiative O(\alpha) corrections to the Drell-Yan process at large invariant dimuon mass have been studied. All formulas for the cross sections and kinematical restrictions are presented in explicit form, for the simplification of calculation and coding the theta- and delta-functions are actively used. The FORTRAN code READY for the numerical analysis in the high energy region corresponding to the future experiments at the CERN Large Hadron Collider has been constructed. To simulate the detector acceptance we used the standard CMS detector cuts. The radiative corrections are found to become large at high dimuon mass M, the complete corrections at "bare" setup change the dimuon mass distribution up to ~ -5.6% (-23.2%; -35.3%) at the LHC energy and M=1 (3; 5)TeV.
[ { "created": "Tue, 20 Feb 2007 14:37:55 GMT", "version": "v1" }, { "created": "Mon, 7 May 2007 18:45:16 GMT", "version": "v2" } ]
2007-05-23
[ [ "Zykunov", "Vladimir A.", "" ] ]
The complete electroweak radiative O(\alpha) corrections to the Drell-Yan process at large invariant dimuon mass have been studied. All formulas for the cross sections and kinematical restrictions are presented in explicit form, for the simplification of calculation and coding the theta- and delta-functions are actively used. The FORTRAN code READY for the numerical analysis in the high energy region corresponding to the future experiments at the CERN Large Hadron Collider has been constructed. To simulate the detector acceptance we used the standard CMS detector cuts. The radiative corrections are found to become large at high dimuon mass M, the complete corrections at "bare" setup change the dimuon mass distribution up to ~ -5.6% (-23.2%; -35.3%) at the LHC energy and M=1 (3; 5)TeV.
hep-ph/0311058
Weizhen Deng
Weizhen Deng, Xiaolin Chen, Dahai Lu, ShiLin Zhu
$SU(3)_F$ Meson Mass Formula from Random Phase Approximation
null
Chin.Phys.Lett. 21 (2004) 624-625
10.1088/0256-307X/21/4/009
null
hep-ph
null
We present a $SU(3)_F$ meson mass formula from random phase approximation (RPA). Both the mesons of ground-state pseudoscalar octet and the ground-state vector octet are described quite well in this mass formula. We also estimate the current and constituent quark masses from the na\"{\i}ve quark model with the PCAC relation.
[ { "created": "Wed, 5 Nov 2003 01:13:36 GMT", "version": "v1" }, { "created": "Fri, 9 Jan 2004 05:48:38 GMT", "version": "v2" } ]
2009-11-10
[ [ "Deng", "Weizhen", "" ], [ "Chen", "Xiaolin", "" ], [ "Lu", "Dahai", "" ], [ "Zhu", "ShiLin", "" ] ]
We present a $SU(3)_F$ meson mass formula from random phase approximation (RPA). Both the mesons of ground-state pseudoscalar octet and the ground-state vector octet are described quite well in this mass formula. We also estimate the current and constituent quark masses from the na\"{\i}ve quark model with the PCAC relation.
1502.06251
Edward Shuryak
Edward Shuryak
Gauge topology and confinement: an update
This is a writeup for proceedings of the 9th International Workshop on Critical Point and Onset of Deconfinement - CPOD2014. A talk of similar structure and content has also been given at The 32nd International Symposium on Lattice Field Theory, Columbia University, New York, June 2014
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the instanton ensemble the fermionic zero modes collectivize and break chiral symmetry. Recent studies of resulting zero mode zone confirm its very small width and overall importance for lattice simulations. Confinement however has been related with completely different topological objects, the magnetic monopoles. Instanton constituents -- instanton dyons, discovered at nonzero holonomy by Pierre van Baal and others -- are able to explain both confinement and chiral symmetry breaking. The talk summarizes recent works deriving the instanton-dyon mutual interactions, and statistical studies of their ensemble. At high density the screening is robust enough to do it analytically, in the mean-field-type approach: we call this limit Dense Dyonic Plasma (DDP). Above $T_c$ the classical interaction between the dyons induce strong correlations and should be studied by direct numerical simulations. Those works are now in progress.
[ { "created": "Sun, 22 Feb 2015 17:23:18 GMT", "version": "v1" } ]
2015-02-24
[ [ "Shuryak", "Edward", "" ] ]
In the instanton ensemble the fermionic zero modes collectivize and break chiral symmetry. Recent studies of resulting zero mode zone confirm its very small width and overall importance for lattice simulations. Confinement however has been related with completely different topological objects, the magnetic monopoles. Instanton constituents -- instanton dyons, discovered at nonzero holonomy by Pierre van Baal and others -- are able to explain both confinement and chiral symmetry breaking. The talk summarizes recent works deriving the instanton-dyon mutual interactions, and statistical studies of their ensemble. At high density the screening is robust enough to do it analytically, in the mean-field-type approach: we call this limit Dense Dyonic Plasma (DDP). Above $T_c$ the classical interaction between the dyons induce strong correlations and should be studied by direct numerical simulations. Those works are now in progress.
hep-ph/0307255
Brent D. Nelson
Brent D. Nelson
Experimental Signatures of Kahler Stabilization of the Dilaton
Proceedings of talk given at "Supergravity at 20," Northeastern University, March 17-21, 2003
null
null
MCTP 03-34
hep-ph
null
We investigate the collider signatures of modular invariant gaugino condensation, with Kahler stabilization of the dilaton, in the context of weakly coupled heterotic string-based models as an example of how supergravity can be used to build a meaningful string phenomenology.
[ { "created": "Sun, 20 Jul 2003 19:22:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nelson", "Brent D.", "" ] ]
We investigate the collider signatures of modular invariant gaugino condensation, with Kahler stabilization of the dilaton, in the context of weakly coupled heterotic string-based models as an example of how supergravity can be used to build a meaningful string phenomenology.
hep-ph/0007286
Kevin Lynch
Kevin R. Lynch, Meenakshi Narain, Elizabeth H. Simmons (Boston U.) and Stephen Mrenna (UC, Davis)
Finding Z' bosons coupled preferentially to the third family at CERN LEP and the Fermilab Tevatron
LaTeX2e, 24 pages (including title page), 13 figures; version 2: corrected typographical errors and bad figure placement; version 3: added references and updated introduction; version 4: changes to compensate for old latex version on arXiv server; version 5: additional references, and embedded fonts in eps files for PRD; version 6: corrected some minor typos to address PRD referee's comments
Phys.Rev.D63:035006,2001
10.1103/PhysRevD.63.035006
BUHEP-00-4, UCD-2000-12
hep-ph hep-ex
null
Z' bosons that couple preferentially to the third generation fermions can arise in models with extended weak (SU(2)xSU(2)) or hypercharge (U(1)xU(1)) gauge groups. We show that existing limits on quark-lepton compositeness set by the LEP and Tevatron experiments translate into lower bounds of order a few hundred GeV on the masses of these Z' bosons. Resonances of this mass can be directly produced at the Tevatron. Accordingly, we explore in detail the limits that can be set at Run II using the process p pbar -> Z' -> tau tau -> e mu. We also comment on the possibility of using hadronically-decaying taus to improve the limits.
[ { "created": "Tue, 25 Jul 2000 21:57:16 GMT", "version": "v1" }, { "created": "Wed, 26 Jul 2000 00:05:47 GMT", "version": "v2" }, { "created": "Fri, 11 Aug 2000 19:19:42 GMT", "version": "v3" }, { "created": "Wed, 16 Aug 2000 20:15:45 GMT", "version": "v4" }, { "created": "Wed, 18 Oct 2000 17:31:13 GMT", "version": "v5" } ]
2011-03-23
[ [ "Lynch", "Kevin R.", "", "Boston U." ], [ "Narain", "Meenakshi", "", "Boston U." ], [ "Simmons", "Elizabeth H.", "", "Boston U." ], [ "Mrenna", "Stephen", "", "UC, Davis" ] ]
Z' bosons that couple preferentially to the third generation fermions can arise in models with extended weak (SU(2)xSU(2)) or hypercharge (U(1)xU(1)) gauge groups. We show that existing limits on quark-lepton compositeness set by the LEP and Tevatron experiments translate into lower bounds of order a few hundred GeV on the masses of these Z' bosons. Resonances of this mass can be directly produced at the Tevatron. Accordingly, we explore in detail the limits that can be set at Run II using the process p pbar -> Z' -> tau tau -> e mu. We also comment on the possibility of using hadronically-decaying taus to improve the limits.
hep-ph/9509355
Peter Cho
Peter Cho
Prompt Upsilon and Psi Production at LEP
15 pages, harvmac, 3 uuencoded figures
Phys.Lett. B368 (1996) 171-178
10.1016/0370-2693(95)01484-5
CALT-68-2020
hep-ph
null
Color-octet contributions to quarkonia production at LEP are studied herein. The short distance formation of heavy quark-antiquark pairs in color-octet configurations via gluon fragmentation processes is significantly enhanced relative to the creation of color-singlet pairs via heavy quark fragmentation. But the subsequent long distance hadronization of these colored pairs into physical quarkonium bound states is suppressed compared to the nonperturbative evolution of their colorless counterparts. We find that the overall LEP rates for gluon fragmentation into prompt Upsilon and Psi vector bosons exceed those from heavy quark fragmentation. Inclusion of the dominant color-octet quarkonium production channel eliminates sizable discrepancies between previous predictions and recent measurements of prompt $Z \to \Jpsi+X$, $Z \to \psi'+X$ and $Z \to \Upsilon+X$ branching fractions.
[ { "created": "Fri, 22 Sep 1995 00:29:33 GMT", "version": "v1" } ]
2009-10-28
[ [ "Cho", "Peter", "" ] ]
Color-octet contributions to quarkonia production at LEP are studied herein. The short distance formation of heavy quark-antiquark pairs in color-octet configurations via gluon fragmentation processes is significantly enhanced relative to the creation of color-singlet pairs via heavy quark fragmentation. But the subsequent long distance hadronization of these colored pairs into physical quarkonium bound states is suppressed compared to the nonperturbative evolution of their colorless counterparts. We find that the overall LEP rates for gluon fragmentation into prompt Upsilon and Psi vector bosons exceed those from heavy quark fragmentation. Inclusion of the dominant color-octet quarkonium production channel eliminates sizable discrepancies between previous predictions and recent measurements of prompt $Z \to \Jpsi+X$, $Z \to \psi'+X$ and $Z \to \Upsilon+X$ branching fractions.
1910.08065
Hajime Fukuda
Hajime Fukuda, Natsumi Nagata, Hideyuki Oide, Hidetoshi Otono and Satoshi Shirai
Cornering Higgsino: Use of Soft Displaced Track
6 pages, 2 figures
Phys. Rev. Lett. 124, 101801 (2020)
10.1103/PhysRevLett.124.101801
KYUSHU-RCAPP-2019-05, UT-19-24, IPMU19-0145
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Higgsino has been intensively searched for in the LHC experiments in recent years. Currently, there is an uncharted region beyond the LEP Higgsino mass limit where the mass splitting between the neutral and charged Higgsinos is around $0.3$-$1$ GEV, which is unexplored by either the soft di-lepton or disappearing track searches. This region is, however, of great importance from a phenomenological point of view, as many supersymmetric models predict such a mass spectrum. In this letter, we propose a possibility of filling this gap by using a soft micro-displaced track on top of the mono-jet event selection, which allows us to discriminate a signature of the charged Higgsino decay from the Standard Model background. It is found that this new strategy is potentially sensitive to a Higgsino mass of $\lesssim 180$ $(250)$ GeV at the LHC Run 2 (HL-LHC) for a charged-neutral mass splitting of $\simeq 0.5$ GeV.
[ { "created": "Thu, 17 Oct 2019 17:54:36 GMT", "version": "v1" }, { "created": "Sun, 20 Oct 2019 22:17:08 GMT", "version": "v2" }, { "created": "Thu, 20 Feb 2020 19:29:45 GMT", "version": "v3" } ]
2020-03-18
[ [ "Fukuda", "Hajime", "" ], [ "Nagata", "Natsumi", "" ], [ "Oide", "Hideyuki", "" ], [ "Otono", "Hidetoshi", "" ], [ "Shirai", "Satoshi", "" ] ]
Higgsino has been intensively searched for in the LHC experiments in recent years. Currently, there is an uncharted region beyond the LEP Higgsino mass limit where the mass splitting between the neutral and charged Higgsinos is around $0.3$-$1$ GEV, which is unexplored by either the soft di-lepton or disappearing track searches. This region is, however, of great importance from a phenomenological point of view, as many supersymmetric models predict such a mass spectrum. In this letter, we propose a possibility of filling this gap by using a soft micro-displaced track on top of the mono-jet event selection, which allows us to discriminate a signature of the charged Higgsino decay from the Standard Model background. It is found that this new strategy is potentially sensitive to a Higgsino mass of $\lesssim 180$ $(250)$ GeV at the LHC Run 2 (HL-LHC) for a charged-neutral mass splitting of $\simeq 0.5$ GeV.
hep-ph/0608026
Stephen P. Martin
Stephen P. Martin
Refined gluino and squark pole masses beyond leading order
14 pages. v2: typos in equations (A.11), (A.17), and (A.18) fixed
Phys.Rev. D74 (2006) 075009
10.1103/PhysRevD.74.075009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The physical pole and running masses of squarks and gluinos have recently been related at two-loop order in a mass-independent renormalization scheme. I propose a general method for improvement of such formulas, and argue that better accuracy results. The improved version gives an imaginary part of the pole mass that agrees exactly with the direct calculation of the physical width at next-to-leading order. I also find the leading three-loop contributions to the gluino pole mass in the case that squarks are heavier, using effective field theory and renormalization group methods. The efficacy of these improvements for the gluino and squarks is illustrated with numerical examples. Some necessary three-loop results for gauge coupling and fermion mass beta functions and pole masses in theories with more than one type of fermion representation, which are not directly accessible from the published literature, are presented in an Appendix.
[ { "created": "Wed, 2 Aug 2006 21:55:22 GMT", "version": "v1" }, { "created": "Tue, 11 Dec 2018 05:33:41 GMT", "version": "v2" } ]
2018-12-12
[ [ "Martin", "Stephen P.", "" ] ]
The physical pole and running masses of squarks and gluinos have recently been related at two-loop order in a mass-independent renormalization scheme. I propose a general method for improvement of such formulas, and argue that better accuracy results. The improved version gives an imaginary part of the pole mass that agrees exactly with the direct calculation of the physical width at next-to-leading order. I also find the leading three-loop contributions to the gluino pole mass in the case that squarks are heavier, using effective field theory and renormalization group methods. The efficacy of these improvements for the gluino and squarks is illustrated with numerical examples. Some necessary three-loop results for gauge coupling and fermion mass beta functions and pole masses in theories with more than one type of fermion representation, which are not directly accessible from the published literature, are presented in an Appendix.
hep-ph/9703411
null
I. Schmidt and J. Soffer
Melosh Rotation and the Nucleon Tensor Charge
8 pages, Latex file, no ps figure
Phys.Lett.B407:331-334,1997
10.1016/S0370-2693(97)00737-5
CPT-97/P.3460
hep-ph
null
By making use of the effect of the Melosh rotation, we show that one can estimate, in a simple way, the nucleon tensor charge in a relativistic quark model formulated on the light-cone. We discuss the physical significance of our results and compare them with those recently obtained in different phenomenological models.
[ { "created": "Tue, 25 Mar 1997 10:20:25 GMT", "version": "v1" } ]
2010-11-19
[ [ "Schmidt", "I.", "" ], [ "Soffer", "J.", "" ] ]
By making use of the effect of the Melosh rotation, we show that one can estimate, in a simple way, the nucleon tensor charge in a relativistic quark model formulated on the light-cone. We discuss the physical significance of our results and compare them with those recently obtained in different phenomenological models.
2008.13442
Qing-Hong Cao
Qing-Hong Cao, Ke-Pan Xie, Hao Zhang, Rui Zhang
A New Observable for Measuring CP Property of Top-Higgs Interaction
null
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new dihedral angle observable to measure the CP property of the interaction of top quark and Higgs boson in the $t\bar{t}H$ production at the 14~TeV LHC. We consider two decay modes of the Higgs boson, $H\to b\bar{b}$ and $H\to \gamma\gamma$ and show that the dihedral angle distribution is able to distinguish the CP-even and the CP-odd hypothesis at 95\% confidence level with an integrated luminosity of $\sim 180~{\rm fb}^{-1}$.
[ { "created": "Mon, 31 Aug 2020 09:04:20 GMT", "version": "v1" } ]
2020-09-01
[ [ "Cao", "Qing-Hong", "" ], [ "Xie", "Ke-Pan", "" ], [ "Zhang", "Hao", "" ], [ "Zhang", "Rui", "" ] ]
We propose a new dihedral angle observable to measure the CP property of the interaction of top quark and Higgs boson in the $t\bar{t}H$ production at the 14~TeV LHC. We consider two decay modes of the Higgs boson, $H\to b\bar{b}$ and $H\to \gamma\gamma$ and show that the dihedral angle distribution is able to distinguish the CP-even and the CP-odd hypothesis at 95\% confidence level with an integrated luminosity of $\sim 180~{\rm fb}^{-1}$.
hep-ph/9406273
Arnd Leike
D. Bardin, A. Leike, T. Riemann
Semi-Analytical Approach to Higgs Production at LEP 2
6 latex pages; 3 figures, feinman.sty and nuclphys.sty included as uuencoded file, CERN-TH.703/94, LMU 08/94
Nucl.Phys.Proc.Suppl.37B:274-278,1994
10.1016/0920-5632(94)90684-X
null
hep-ph
null
The cross-section for the reaction $e^+e^- \rightarrow b\bar{b}\mu^+\mu^-$ is calculated with a semi-analytical integration of the phase space. Compact formulae are obtained for the total cross section and for invariant mass distributions of the $\mu^+\mu^-$ and $b\bar{b}$ pairs. The background diagrams to $ZH$ production yield analytically cumbersome but numerically small contributions. The numerical results are compared with those from a Monte Carlo approach.
[ { "created": "Fri, 10 Jun 1994 09:50:07 GMT", "version": "v1" } ]
2011-01-25
[ [ "Bardin", "D.", "" ], [ "Leike", "A.", "" ], [ "Riemann", "T.", "" ] ]
The cross-section for the reaction $e^+e^- \rightarrow b\bar{b}\mu^+\mu^-$ is calculated with a semi-analytical integration of the phase space. Compact formulae are obtained for the total cross section and for invariant mass distributions of the $\mu^+\mu^-$ and $b\bar{b}$ pairs. The background diagrams to $ZH$ production yield analytically cumbersome but numerically small contributions. The numerical results are compared with those from a Monte Carlo approach.
hep-ph/9702320
Christopher T. Hill
Christopher T. Hill (Fermilab)
``Topcolor''; Invited talk presented at "Strongly Coupled Gauge Theories, 1996", Nagoya, Japan, Nov. 1996
19 pages, Latex. No Figures included. email: Hill@fnal.gov
null
null
FERMILAB-Conf-97/032-T
hep-ph
null
We review a class of dynamical models in which top condensation occurs at the weak scale, giving rise to the large top quark mass and other phenomena. This typically requires a color embedding, $SU(3)_c \rightarrow SU(3)_1\times SU(3)_2$. These models imply many signatures addressable in near term experiments at colliders and in fixed target mode.
[ { "created": "Wed, 12 Feb 1997 21:27:59 GMT", "version": "v1" } ]
2016-09-06
[ [ "Hill", "Christopher T.", "", "Fermilab" ] ]
We review a class of dynamical models in which top condensation occurs at the weak scale, giving rise to the large top quark mass and other phenomena. This typically requires a color embedding, $SU(3)_c \rightarrow SU(3)_1\times SU(3)_2$. These models imply many signatures addressable in near term experiments at colliders and in fixed target mode.
hep-ph/9612215
Gestt Trentadue
N.P. Merenkov (PTI Kharkov)
Small angle Bhabha scattering at LEP1. Wide-narrow angular acceptance
33 pages, LaTeX, submitted to ZhETF
J.Exp.Theor.Phys. 85 (1997) 217-233; Zh.Eksp.Teor.Fiz. 112 (1997) 400-428
10.1134/1.558268
null
hep-ph
null
Analytical method is applied for description of the small angle Bhabha scattering at LEP1. Inclusive event selection for asymmetrical wide-narrow circular detectors is considered. The QED correction to the Born cross-section is calculated with leading and next-to-leading accuracy in the second order of perturbation theory and with leading one --- in the third order. All contributions in the second order due to photonic radiative corrections and pair production are calculated starting from essential Feynman diagrams. The third order correction is computed by means of electron structure function. Numerical results illustrate the analytical calculsations.
[ { "created": "Sat, 30 Nov 1996 16:37:22 GMT", "version": "v1" } ]
2009-10-30
[ [ "Merenkov", "N. P.", "", "PTI Kharkov" ] ]
Analytical method is applied for description of the small angle Bhabha scattering at LEP1. Inclusive event selection for asymmetrical wide-narrow circular detectors is considered. The QED correction to the Born cross-section is calculated with leading and next-to-leading accuracy in the second order of perturbation theory and with leading one --- in the third order. All contributions in the second order due to photonic radiative corrections and pair production are calculated starting from essential Feynman diagrams. The third order correction is computed by means of electron structure function. Numerical results illustrate the analytical calculsations.
0903.0564
David Emmanuel-Costa
D. Emmanuel-Costa, C. Simoes
Reconstruction of Quark Mass Matrices with Weak Basis Texture Zeroes from Experimental Input
RevTeX4, 3 tables, 21 pages; misprints corrected and one reference added
null
10.1103/PhysRevD.79.073006
CFTP-IST/09-18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
All quark mass matrices with texture zeroes obtained through weak basis transformations are confronted with the experimental data. The reconstruction of the quark mass matrices M_u and M_d at the electroweak scale is performed in a weak basis where the matrices are Hermitian and have a maximum of three vanishing elements. The same procedure is also accomplished for the Yukawa coupling matrices at the grand unification scale in the context of the Standard Model and its minimal supersymmetric extension as well as of the two Higgs doublet model. The analysis of all viable power structures on the quark Yukawa coupling matrices that could naturally appear from a Froggatt-Nielsen mechanism is also presented.
[ { "created": "Tue, 3 Mar 2009 20:16:04 GMT", "version": "v1" }, { "created": "Thu, 12 Mar 2009 16:23:21 GMT", "version": "v2" } ]
2013-05-29
[ [ "Emmanuel-Costa", "D.", "" ], [ "Simoes", "C.", "" ] ]
All quark mass matrices with texture zeroes obtained through weak basis transformations are confronted with the experimental data. The reconstruction of the quark mass matrices M_u and M_d at the electroweak scale is performed in a weak basis where the matrices are Hermitian and have a maximum of three vanishing elements. The same procedure is also accomplished for the Yukawa coupling matrices at the grand unification scale in the context of the Standard Model and its minimal supersymmetric extension as well as of the two Higgs doublet model. The analysis of all viable power structures on the quark Yukawa coupling matrices that could naturally appear from a Froggatt-Nielsen mechanism is also presented.
2111.09994
Adolfo Guevara
Adolfo Guevara, Gabriel L\'opez Castro and Pablo Roig
Improved description of di-lepton production in $\tau^-\to\nu_\tau P^-$ decays
28 pages, 14 figures, 3 tables
Phys. Rev. D 105, 076007 (2022)
10.1103/PhysRevD.105.076007
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Recently, the Belle collaboration reported the first measurements of the $\tau^- \to\nu_{\tau}\pi^-e^+e^-$ branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this branching fraction which turned out to be compatible with that reported by Belle, although with a large uncertainty. This is the motivation to seek for improvements on our previous evaluation of $\tau^- \to \nu_{\tau}\pi^-\ell^+\ell^-$ decays ($\ell=e,\,\mu$). In this paper we improve our calculation of the $WP^-\gamma^*$ vertex by including flavour symmetry breaking effects in the framework of the Resonance Chiral Theory. We impose QCD short-distance behaviour to constrain most parameters and data on the $\pi^-e^+e^-$ spectrum reported by Belle to fix the remaining free ones. As a result, improved predictions for the branching ratios and hadronic/leptonic spectra are reported, in good agreement with observations. Analogous calculations for the strangeness-changing $\tau^- \to \nu_{\tau}K^-\ell^+\ell^-$ transitions are reported for the first time. Albeit one expects the $m_{\pi\mu^+\mu^-}$ spectrum to be measured in Belle-II and the observables with $\ell=e$ can be improved, it is rather unlikely that the $K$ channels can be measured due to the suppression factor $|V_{ud}/V_{us}|^2=0.05$.
[ { "created": "Fri, 19 Nov 2021 01:12:13 GMT", "version": "v1" }, { "created": "Tue, 8 Mar 2022 15:49:44 GMT", "version": "v2" } ]
2022-04-14
[ [ "Guevara", "Adolfo", "" ], [ "Castro", "Gabriel López", "" ], [ "Roig", "Pablo", "" ] ]
Recently, the Belle collaboration reported the first measurements of the $\tau^- \to\nu_{\tau}\pi^-e^+e^-$ branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this branching fraction which turned out to be compatible with that reported by Belle, although with a large uncertainty. This is the motivation to seek for improvements on our previous evaluation of $\tau^- \to \nu_{\tau}\pi^-\ell^+\ell^-$ decays ($\ell=e,\,\mu$). In this paper we improve our calculation of the $WP^-\gamma^*$ vertex by including flavour symmetry breaking effects in the framework of the Resonance Chiral Theory. We impose QCD short-distance behaviour to constrain most parameters and data on the $\pi^-e^+e^-$ spectrum reported by Belle to fix the remaining free ones. As a result, improved predictions for the branching ratios and hadronic/leptonic spectra are reported, in good agreement with observations. Analogous calculations for the strangeness-changing $\tau^- \to \nu_{\tau}K^-\ell^+\ell^-$ transitions are reported for the first time. Albeit one expects the $m_{\pi\mu^+\mu^-}$ spectrum to be measured in Belle-II and the observables with $\ell=e$ can be improved, it is rather unlikely that the $K$ channels can be measured due to the suppression factor $|V_{ud}/V_{us}|^2=0.05$.
hep-ph/9405334
Giovanni Amelino-Camelia
G. Amelino-Camelia, F. Buccella, and L. Rosa
Majorana Masses for Neutrinos in SO(10)
published in Proceedings of the Second International Workshop on Neutrino Telescopes, VENEZIA/2/13-15/90, edited by Milla Baldo Ceolin (1990), Plain Tex, (1 figure not included)
null
null
null
hep-ph
null
We study the predictions for Majorana masses for neutrinos in SO(10) grandunification models. (This paper precedes and is cited in the article "PROTON DECAY AND NEUTRINO MASSES IN SO(10)", hep-ph/9405332)
[ { "created": "Thu, 19 May 1994 20:18:34 GMT", "version": "v1" } ]
2009-09-25
[ [ "Amelino-Camelia", "G.", "" ], [ "Buccella", "F.", "" ], [ "Rosa", "L.", "" ] ]
We study the predictions for Majorana masses for neutrinos in SO(10) grandunification models. (This paper precedes and is cited in the article "PROTON DECAY AND NEUTRINO MASSES IN SO(10)", hep-ph/9405332)
1211.4004
Marco Battaglia
A. Arbey, M. Battaglia, A. Djouadi and F. Mahmoudi
An update of the constraints on the phenomenological MSSM from the new LHC Higgs results
14 pages, 8 figures. This update is based on results presented at HCP 2012 and the December 2012 CERN Council LHC Jamboree. It features larger scan statistics and additional plots
Physics Letters B 720 (2013), pp. 153-160
10.1016/j.physletb.2013.02.001
CERN-PH-TH/2012-316; LPT-ORSAY-12/111
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Updated results on the search of Higgs bosons at the LHC with up to 17/fb of data have just been presented by the ATLAS and CMS collaborations. New constraints are provided by the LHCb and XENON experiments with the observation of the rare decay B_s -> mu+mu- and new limits on dark matter direct detection. In this paper, we update and extend the results on the implications of these data on the phenomenological Minimal Supersymmetric extension of the Standard Model (pMSSM) by using high statistics, flat scans of its 19 parameters. The new LHC data on bb and tau tau decays of the lightest Higgs state and the new CMS limits from the tau tau searches for the heavier Higgs states set stronger constraints on the pMSSM parameter space.
[ { "created": "Fri, 16 Nov 2012 20:02:17 GMT", "version": "v1" }, { "created": "Tue, 26 Feb 2013 17:01:31 GMT", "version": "v2" } ]
2013-02-27
[ [ "Arbey", "A.", "" ], [ "Battaglia", "M.", "" ], [ "Djouadi", "A.", "" ], [ "Mahmoudi", "F.", "" ] ]
Updated results on the search of Higgs bosons at the LHC with up to 17/fb of data have just been presented by the ATLAS and CMS collaborations. New constraints are provided by the LHCb and XENON experiments with the observation of the rare decay B_s -> mu+mu- and new limits on dark matter direct detection. In this paper, we update and extend the results on the implications of these data on the phenomenological Minimal Supersymmetric extension of the Standard Model (pMSSM) by using high statistics, flat scans of its 19 parameters. The new LHC data on bb and tau tau decays of the lightest Higgs state and the new CMS limits from the tau tau searches for the heavier Higgs states set stronger constraints on the pMSSM parameter space.
2112.12395
Oleksandr Tomalak
Oleksandr Tomalak
Radiative (anti)neutrino energy spectra from muon, pion, and kaon decays
14 pages, 2 figures. v2: journal version; minor corrections
Phys. Lett. B 829, 137108 (2022)
10.1016/j.physletb.2022.137108
LA-UR-21-30638, FERMILAB-PUB-21-739-T
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
To describe low-energy (anti)neutrino fluxes in modern coherent elastic neutrino-nucleus scattering experiments as well as high-energy fluxes in precision-frontier projects such as the Enhanced NeUtrino BEams from kaon Tagging (ENUBET) and the Neutrinos from STORed Muons (nuSTORM), we evaluate (anti)neutrino energy spectra from radiative muon ($\mu^- \to e^- \bar{\nu}_e \nu_\mu (\gamma),~\mu^+ \to e^+ {\nu}_e \bar{\nu}_\mu (\gamma)$), pion $\pi_{\ell 2}$ ($\pi^- \to \mu^- \bar{\nu}_\mu (\gamma),~\pi^+ \to \mu^+ {\nu}_\mu (\gamma)$), and kaon $K_{\ell 2}$ ($K^- \to \mu^- \bar{\nu}_\mu (\gamma),~K^+ \to \mu^+ {\nu}_\mu (\gamma)$) decays. We compare detailed $\mathrm{O} \left( \alpha \right)$ distributions to the well-known tree-level results, investigate electron-mass corrections and provide energy spectra in analytical form. Radiative corrections introduce continuous and divergent spectral components near the endpoint, on top of the monochromatic tree-level meson-decay spectra, which can change the flux-averaged cross section at $6\times 10^{-5}$ level for the scattering on $^{40}\mathrm{Ar}$ nucleus with (anti)neutrinos from the pion decay at rest. Radiative effects modify the expected (anti)neutrino fluxes from the muon decay around the peak region by $3-4$ permille, which is a precision goal for next-generation artificial neutrino sources.
[ { "created": "Thu, 23 Dec 2021 07:38:50 GMT", "version": "v1" }, { "created": "Mon, 25 Apr 2022 17:21:49 GMT", "version": "v2" } ]
2022-04-27
[ [ "Tomalak", "Oleksandr", "" ] ]
To describe low-energy (anti)neutrino fluxes in modern coherent elastic neutrino-nucleus scattering experiments as well as high-energy fluxes in precision-frontier projects such as the Enhanced NeUtrino BEams from kaon Tagging (ENUBET) and the Neutrinos from STORed Muons (nuSTORM), we evaluate (anti)neutrino energy spectra from radiative muon ($\mu^- \to e^- \bar{\nu}_e \nu_\mu (\gamma),~\mu^+ \to e^+ {\nu}_e \bar{\nu}_\mu (\gamma)$), pion $\pi_{\ell 2}$ ($\pi^- \to \mu^- \bar{\nu}_\mu (\gamma),~\pi^+ \to \mu^+ {\nu}_\mu (\gamma)$), and kaon $K_{\ell 2}$ ($K^- \to \mu^- \bar{\nu}_\mu (\gamma),~K^+ \to \mu^+ {\nu}_\mu (\gamma)$) decays. We compare detailed $\mathrm{O} \left( \alpha \right)$ distributions to the well-known tree-level results, investigate electron-mass corrections and provide energy spectra in analytical form. Radiative corrections introduce continuous and divergent spectral components near the endpoint, on top of the monochromatic tree-level meson-decay spectra, which can change the flux-averaged cross section at $6\times 10^{-5}$ level for the scattering on $^{40}\mathrm{Ar}$ nucleus with (anti)neutrinos from the pion decay at rest. Radiative effects modify the expected (anti)neutrino fluxes from the muon decay around the peak region by $3-4$ permille, which is a precision goal for next-generation artificial neutrino sources.
1705.11113
Chandrasekhar Chatterjee
Chandrasekhar Chatterjee and Muneto Nitta
Stable non-Abelian semi-superfluid vortices in dense QCD
Prepared for proceedings of Quarks and Compact Stars 2017 to be published in JPS Conf. Proc
null
10.7566/JPSCP.20.011012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Color superconductivity is expected to be formed in high density quark matter where color symmetry is spontaneously broken in the presence of di-quark condensate. Stable non-Abelian vortices or color magnetic flux tubes exist in the color-flavor locked phase at asymptotically high density. $\mathbb{C}P^2$ Nambu-Goldstone(NG) bosons and Majorana fermions belonging to the triplet representation are localized around a non-Abelian vortex. We discuss the zero mode analysis and the low-energy effective world sheet theory of a non-Abelian vortex. We determine the interactions of these bosonic and fermionic modes by using the nonlinear realization method. We also discuss the Aharanov-Bohm (AB) phases of charged particles, such as, electrons, muons, and color-flavor locked mesons made of tetra-quarks encircling around a non-Abelian vortex in the presence of electro-magnetic fields. This is a review based on our recent works arXiv:1602.01677, arXiv:1512.06603, arXiv:1612.09419.
[ { "created": "Wed, 31 May 2017 14:33:33 GMT", "version": "v1" } ]
2018-02-14
[ [ "Chatterjee", "Chandrasekhar", "" ], [ "Nitta", "Muneto", "" ] ]
Color superconductivity is expected to be formed in high density quark matter where color symmetry is spontaneously broken in the presence of di-quark condensate. Stable non-Abelian vortices or color magnetic flux tubes exist in the color-flavor locked phase at asymptotically high density. $\mathbb{C}P^2$ Nambu-Goldstone(NG) bosons and Majorana fermions belonging to the triplet representation are localized around a non-Abelian vortex. We discuss the zero mode analysis and the low-energy effective world sheet theory of a non-Abelian vortex. We determine the interactions of these bosonic and fermionic modes by using the nonlinear realization method. We also discuss the Aharanov-Bohm (AB) phases of charged particles, such as, electrons, muons, and color-flavor locked mesons made of tetra-quarks encircling around a non-Abelian vortex in the presence of electro-magnetic fields. This is a review based on our recent works arXiv:1602.01677, arXiv:1512.06603, arXiv:1612.09419.
hep-ph/9411343
Taekoon Lee
TAekoon Lee
Anomalous Cross Section from Perturbation Theory
19 pages
null
null
FERMILAB-PUB-94/385-T
hep-ph
null
We present the anomalous cross section for baryon number violation in the standard model from the perturbation of large-order behavior of forward scattering amplitudes to the order $\left(\epsilon /n\right)^{8/3} \ln\left(\epsilon /n\right)$. An improved high energy behavior of the anomalous cross section is observed. We also argue that the asymptotic form of $F(\epsilon g) \equiv -g \ln \sigma_{ano} $ is given in the form: $F(\epsilon g) \rightarrow d + c \cdot \epsilon g $ for $ \epsilon g \rightarrow \infty$ with $c, d $ constants satisfying $c, d \geq 0$, and $F(\epsilon g) >0$ for all energies. The constants are not determined.
[ { "created": "Mon, 21 Nov 1994 02:27:46 GMT", "version": "v1" } ]
2009-09-25
[ [ "Lee", "TAekoon", "" ] ]
We present the anomalous cross section for baryon number violation in the standard model from the perturbation of large-order behavior of forward scattering amplitudes to the order $\left(\epsilon /n\right)^{8/3} \ln\left(\epsilon /n\right)$. An improved high energy behavior of the anomalous cross section is observed. We also argue that the asymptotic form of $F(\epsilon g) \equiv -g \ln \sigma_{ano} $ is given in the form: $F(\epsilon g) \rightarrow d + c \cdot \epsilon g $ for $ \epsilon g \rightarrow \infty$ with $c, d $ constants satisfying $c, d \geq 0$, and $F(\epsilon g) >0$ for all energies. The constants are not determined.
hep-ph/9708321
Georg Weiglein
G. Weiglein
Precise Predictions for the W-Boson Mass
14 pages, LaTeX, 4 Postscript figures; talk given at the Cracow Epiphany Conference on W Boson, Cracow, January 1997; the paper is also available via www at http://www-itp.physik.uni-karlsruhe.de/prep/prep97/preplist97.html
Acta Phys.Polon.B28:1381-1394,1997
null
KA-TP-06-1997
hep-ph
null
Recent results for higher-order corrections to the relation between the vector-boson masses in the Standard Model and Supersymmetry are summarized. In the Standard Model, the Higgs-mass dependence of the two-loop contributions to Delta r is studied. Exact results are given for the Higgs-dependent two-loop corrections associated with the fermions, i.e. no expansion in the top-quark and the Higgs-boson mass is made. The results for the top quark are compared with results of an expansion up to next-to-leading order in the top-quark mass. Agreement is found within 30 % of the two-loop result. In Supersymmetry, the two-loop QCD corrections to the stop- and sbottom-loop contributions to the rho parameter are presented. The two-loop corrections modify the one-loop contribution by up to 30 %; the gluino decouples for large masses. Contrary to the SM case where the QCD corrections are negative and screen the one-loop value, the corresponding corrections in the supersymmetric case are in general positive, increasing the sensitivity in the search for scalar quarks through their virtual effects in high-precision electroweak observables.
[ { "created": "Tue, 12 Aug 1997 13:32:35 GMT", "version": "v1" } ]
2011-03-17
[ [ "Weiglein", "G.", "" ] ]
Recent results for higher-order corrections to the relation between the vector-boson masses in the Standard Model and Supersymmetry are summarized. In the Standard Model, the Higgs-mass dependence of the two-loop contributions to Delta r is studied. Exact results are given for the Higgs-dependent two-loop corrections associated with the fermions, i.e. no expansion in the top-quark and the Higgs-boson mass is made. The results for the top quark are compared with results of an expansion up to next-to-leading order in the top-quark mass. Agreement is found within 30 % of the two-loop result. In Supersymmetry, the two-loop QCD corrections to the stop- and sbottom-loop contributions to the rho parameter are presented. The two-loop corrections modify the one-loop contribution by up to 30 %; the gluino decouples for large masses. Contrary to the SM case where the QCD corrections are negative and screen the one-loop value, the corresponding corrections in the supersymmetric case are in general positive, increasing the sensitivity in the search for scalar quarks through their virtual effects in high-precision electroweak observables.
hep-ph/9305310
null
A. Djouadi, M. Drees and H. K\"onig
Supersymmetric QCD corrections to quark pair production in e+ e- annihilation
17 pages, LaTeX with EQUATION.STY, 4 figures available on request; MAD/PH/754
Phys.Rev. D48 (1993) 3081-3089
10.1103/PhysRevD.48.3081
null
hep-ph
null
We calculate supersymmetric QCD corrections (squark/gluino loops) to quark pair production in e+ e- annihilation, allowing for mixing between left- and right-handed squarks and taking into account the effects of nonzero quark masses. Corrections to the Z boson partial widths are generally small and positive, except in the case of large b-squark mixing, where they become negative. At high-energy e+ e- colliders, larger corrections to the total cross sections are possible. Corrections to forward-backward asymmetries are negligible except possibly for top quarks, where they are sensitive to t-squark mixing. We also comment on the possibility that the gluino mass is only a few GeV.
[ { "created": "Tue, 25 May 1993 00:57:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Djouadi", "A.", "" ], [ "Drees", "M.", "" ], [ "König", "H.", "" ] ]
We calculate supersymmetric QCD corrections (squark/gluino loops) to quark pair production in e+ e- annihilation, allowing for mixing between left- and right-handed squarks and taking into account the effects of nonzero quark masses. Corrections to the Z boson partial widths are generally small and positive, except in the case of large b-squark mixing, where they become negative. At high-energy e+ e- colliders, larger corrections to the total cross sections are possible. Corrections to forward-backward asymmetries are negligible except possibly for top quarks, where they are sensitive to t-squark mixing. We also comment on the possibility that the gluino mass is only a few GeV.
1403.6729
Kim Maltman
P.A. Boyle, L. Del Debbio, N. Garron, R.J. Hudspith, E. Kerrane, K. Maltman and J.M. Zanotti
A Combined NNLO Lattice-Continuum Determination of $L_{10}^r$
21 pages, 4 figures, 1 table. Updated references, one additional clarifying footnote in discussion section
Phys. Rev. D 89, 094510 (2014)
10.1103/PhysRevD.89.094510
Trinity College Dublin preprint TCDMATH14--02, University of Adelaide preprint ADP-14-6/T864
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The renormalized next-to-leading-order (NLO) chiral low-energy constant, $L_{10}^r$, is determined in a complete next-to-next-to-leading-order (NNLO) analysis, using a combination of lattice and continuum data for the flavor $ud$ $V-A$ correlator and results from a recent chiral sum-rule analysis of the flavor-breaking combination of $ud$ and $us$ $V-A$ correlator differences. The analysis also fixes two combinations of NNLO low-energy constants, the determination of which is crucial to the precision achieved for $L_{10}^r$. Using the results of the flavor-breaking chiral $V-A$ sum rule obtained with current versions of the strange hadronic $\tau$ branching fractions as input, we find $L_{10}^r(m_\rho )\, =\, -0.00346(32)$. This result represents the first NNLO determination of $L_{10}^r$ having all inputs under full theoretical and/or experimental control, and the best current precision for this quantity.
[ { "created": "Wed, 26 Mar 2014 16:02:14 GMT", "version": "v1" }, { "created": "Wed, 23 Apr 2014 13:59:04 GMT", "version": "v2" } ]
2014-06-11
[ [ "Boyle", "P. A.", "" ], [ "Del Debbio", "L.", "" ], [ "Garron", "N.", "" ], [ "Hudspith", "R. J.", "" ], [ "Kerrane", "E.", "" ], [ "Maltman", "K.", "" ], [ "Zanotti", "J. M.", "" ] ]
The renormalized next-to-leading-order (NLO) chiral low-energy constant, $L_{10}^r$, is determined in a complete next-to-next-to-leading-order (NNLO) analysis, using a combination of lattice and continuum data for the flavor $ud$ $V-A$ correlator and results from a recent chiral sum-rule analysis of the flavor-breaking combination of $ud$ and $us$ $V-A$ correlator differences. The analysis also fixes two combinations of NNLO low-energy constants, the determination of which is crucial to the precision achieved for $L_{10}^r$. Using the results of the flavor-breaking chiral $V-A$ sum rule obtained with current versions of the strange hadronic $\tau$ branching fractions as input, we find $L_{10}^r(m_\rho )\, =\, -0.00346(32)$. This result represents the first NNLO determination of $L_{10}^r$ having all inputs under full theoretical and/or experimental control, and the best current precision for this quantity.
hep-ph/0403284
A. A. Arkhipov
A.A. Arkhipov
What Can we Learn about $\Theta$ Baryon from Unified Picture for Hadron Spectra
28 pages, 13 figures, 2 Tables; misprint removed; analysis of ZEUS and DUBNA PBC experiments added, discussion extended, references added
null
null
null
hep-ph hep-ex nucl-ex
null
An analysis of the recent results from several experimental groups reported observation of a new $\Theta$ baryon has been presented from a view point of the unified picture for hadron spectra developed early \cite{12}. It is shown that, in fact, two different $\Theta$ baryons have been discovered. We have also established that both $\Theta$ baryons are excellently incorporated in the unified picture for hadron spectra. It is argued that the presented experimental material revealed an existence of the positive srangeness $\Theta$ partners for the observed $\Lambda$ and $\Sigma$ states with negative strangeness as we predicted.
[ { "created": "Mon, 29 Mar 2004 17:35:33 GMT", "version": "v1" }, { "created": "Mon, 5 Apr 2004 16:55:34 GMT", "version": "v2" }, { "created": "Tue, 25 May 2004 16:54:44 GMT", "version": "v3" } ]
2007-05-23
[ [ "Arkhipov", "A. A.", "" ] ]
An analysis of the recent results from several experimental groups reported observation of a new $\Theta$ baryon has been presented from a view point of the unified picture for hadron spectra developed early \cite{12}. It is shown that, in fact, two different $\Theta$ baryons have been discovered. We have also established that both $\Theta$ baryons are excellently incorporated in the unified picture for hadron spectra. It is argued that the presented experimental material revealed an existence of the positive srangeness $\Theta$ partners for the observed $\Lambda$ and $\Sigma$ states with negative strangeness as we predicted.
2203.16881
Tingfei Li
Bo Feng, Tingfei Li
PV-Reduction of Sunset Topology with Auxiliary Vector
36 pages,1 figure, 3 tables
null
10.1088/1572-9494/ac7f97
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
Passarino-Veltman (PV) reduction method has been proved to be very useful for the computation of general one-loop integrals. However, not much progress has been made when applying to higher loops. Recently, we have improved the PV-reduction method by introducing an auxiliary vector. In this paper, we apply our new method to the simplest two-loop integrals, i.e., the sunset topology. We show how to use differential operators to establish algebraic recursion relations for reduction coefficients. Our algorithm can be easily applied to the reduction of integrals with arbitrary high-rank tensor structures. We demonstrate the efficiency of our algorithm by computing the reduction with the total tensor rank up to four.
[ { "created": "Thu, 31 Mar 2022 08:21:27 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2022 11:36:10 GMT", "version": "v2" }, { "created": "Tue, 12 Jul 2022 14:30:46 GMT", "version": "v3" } ]
2022-09-14
[ [ "Feng", "Bo", "" ], [ "Li", "Tingfei", "" ] ]
Passarino-Veltman (PV) reduction method has been proved to be very useful for the computation of general one-loop integrals. However, not much progress has been made when applying to higher loops. Recently, we have improved the PV-reduction method by introducing an auxiliary vector. In this paper, we apply our new method to the simplest two-loop integrals, i.e., the sunset topology. We show how to use differential operators to establish algebraic recursion relations for reduction coefficients. Our algorithm can be easily applied to the reduction of integrals with arbitrary high-rank tensor structures. We demonstrate the efficiency of our algorithm by computing the reduction with the total tensor rank up to four.
hep-ph/9907417
Mary Alberg
Mary Alberg (1 and 2), Ernest M. Henley (1 and 3), and Gerald A. Miller (1) ((1) University of Washington, (2) Seattle University, (3) Institute for Nuclear Theory)
Omega Meson Cloud and the Proton's Light Anti-Quark Distribution
6 pages, 2 figures, LaTex
Phys.Lett.B471:396-399,2000
10.1016/S0370-2693(99)01419-7
NT@UW-99-37
hep-ph nucl-th
null
We use the meson cloud model of the nucleon to calculate distribution functions for $(\bar {d} - \bar{u})$ and $ \bar{d}/\bar{u}$ in the proton. Including the effect of the omega meson cloud, with a coupling constant $g_\omega^2/4\pi\approx 8$, allows a reasonably good description of the data.
[ { "created": "Mon, 19 Jul 1999 18:14:13 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alberg", "Mary", "", "1 and 2" ], [ "Henley", "Ernest M.", "", "1 and 3" ], [ "Miller", "Gerald A.", "" ] ]
We use the meson cloud model of the nucleon to calculate distribution functions for $(\bar {d} - \bar{u})$ and $ \bar{d}/\bar{u}$ in the proton. Including the effect of the omega meson cloud, with a coupling constant $g_\omega^2/4\pi\approx 8$, allows a reasonably good description of the data.
1504.07126
Yuji Omura
Yuji Omura
Natural SUSY from unification of SUSY breaking and GUT breaking
4 pages, 4 figures, to appear in the proceedings of Toyama International Workshop on Higgs as a Probe of New Physics 2015, 11-15, February, 2015
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce an explicit supersymmetric unification model where grand unified gauge symmetry breaking and supersymmetry (SUSY) breaking are caused by the same field. Besides, the SM-charged particles are also predicted by the symmetry breaking sector, and their loop corrections induce the soft SUSY breaking terms. Especially, nonzero A-term and B-term are generated at one-loop level according to the mediation via the vector superfields, so that the electro-weak symmetry breaking and 125 GeV Higgs mass could be achieved even if the stop mass is around 1 TeV.
[ { "created": "Mon, 27 Apr 2015 15:12:30 GMT", "version": "v1" } ]
2015-04-28
[ [ "Omura", "Yuji", "" ] ]
We introduce an explicit supersymmetric unification model where grand unified gauge symmetry breaking and supersymmetry (SUSY) breaking are caused by the same field. Besides, the SM-charged particles are also predicted by the symmetry breaking sector, and their loop corrections induce the soft SUSY breaking terms. Especially, nonzero A-term and B-term are generated at one-loop level according to the mediation via the vector superfields, so that the electro-weak symmetry breaking and 125 GeV Higgs mass could be achieved even if the stop mass is around 1 TeV.
hep-ph/9305293
Felix Schlumpf
Felix Schlumpf
Magnetic Moments of the Baryon Decuplet in a Relativistic Quark Model
10 pages ReVTeX, SLAC-PUB-6218
Phys.Rev. D48 (1993) 4478-4480
10.1103/PhysRevD.48.4478
null
hep-ph
null
The magnetic moments of the baryon decuplet are calculated in a relativistic constituent quark model using the light-front formalism. Of particular interest are the magnetic moments of the $\Omega^-$ and $\Delta^{++}$ for which new recent experimental measurements are available. Our calculation for the magnetic moment ratio $\mu(\Delta^{++})/\mu(p)$ is in excellent agreement with the experimental ratio, while our ratio $\mu(\Omega^-)/\mu(\Lambda^0)$ is slightly higher than the experimental ratio.
[ { "created": "Thu, 20 May 1993 20:18:37 GMT", "version": "v1" } ]
2009-10-22
[ [ "Schlumpf", "Felix", "" ] ]
The magnetic moments of the baryon decuplet are calculated in a relativistic constituent quark model using the light-front formalism. Of particular interest are the magnetic moments of the $\Omega^-$ and $\Delta^{++}$ for which new recent experimental measurements are available. Our calculation for the magnetic moment ratio $\mu(\Delta^{++})/\mu(p)$ is in excellent agreement with the experimental ratio, while our ratio $\mu(\Omega^-)/\mu(\Lambda^0)$ is slightly higher than the experimental ratio.
hep-ph/9412234
Michael Martin Nieto
Michael Martin Nieto, T. Goldman, John D. Anderson, Eunice L. Lau, and J. P\'erez-Mercader
Theoretical Motivation for Gravitation Experiments on Ultra-Low Energy Antiprotons and Antihydrogen
Written version of invited contribution to LEAP'94: Third Biennial Conference on Low-Energy Antiproton Physics. LaTeX, 9 pages
Third Biennial Conference on Low-Energy Antiproton Physics, LEAP'94, ed. G. Kernel, P. Krizan, and M. Mikuz (World Sci. 1995) 606
null
LA-UR-94-3953; LAEFF-94/14
hep-ph astro-ph gr-qc
null
We know that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when we try to combine these theories, we must beware of physical pitfalls. Modern theories of quantum gravity are trying to overcome these problems. Any ideas must confront the present agreement with general relativity, but yet be free to wonder about not understood phenomena, such as the dark matter problem and the anomalous spacecraft data which we announce here. This all has led some ``intrepid" theorists to consider a new gravitational regime, that of antimatter. Even more ``daring" experimentalists are attempting, or considering attempting, the measurement of the gravitational force on antimatter, including low-energy antiprotons and, perhaps most enticing, antihydrogen.
[ { "created": "Mon, 5 Dec 1994 16:52:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nieto", "Michael Martin", "" ], [ "Goldman", "T.", "" ], [ "Anderson", "John D.", "" ], [ "Lau", "Eunice L.", "" ], [ "Pérez-Mercader", "J.", "" ] ]
We know that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when we try to combine these theories, we must beware of physical pitfalls. Modern theories of quantum gravity are trying to overcome these problems. Any ideas must confront the present agreement with general relativity, but yet be free to wonder about not understood phenomena, such as the dark matter problem and the anomalous spacecraft data which we announce here. This all has led some ``intrepid" theorists to consider a new gravitational regime, that of antimatter. Even more ``daring" experimentalists are attempting, or considering attempting, the measurement of the gravitational force on antimatter, including low-energy antiprotons and, perhaps most enticing, antihydrogen.
hep-ph/0511265
Robertus Potting
R. Lehnert and R. Potting
Vacuum Cherenkov radiation in Maxwell-Chern-Simons electrodynamics
9 pages, 3 figures, presented at the Third Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, August 2004
null
10.1142/9789812702173_0025
null
hep-ph
null
We study the Cherenkov effect in the context of the Maxwell-Chern-Simons (MCS) limit of the Standard Model Extension. We present a method to determine the exact radiation rate for a point charge.
[ { "created": "Tue, 22 Nov 2005 22:36:47 GMT", "version": "v1" } ]
2016-11-03
[ [ "Lehnert", "R.", "" ], [ "Potting", "R.", "" ] ]
We study the Cherenkov effect in the context of the Maxwell-Chern-Simons (MCS) limit of the Standard Model Extension. We present a method to determine the exact radiation rate for a point charge.
1603.03772
John Kearney
Roni Harnik, Kiel Howe and John Kearney
Tadpole-Induced Electroweak Symmetry Breaking and pNGB Higgs Models
21 pages, 5 figures
null
10.1007/JHEP03(2017)111
FERMILAB-PUB-16-076-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate induced electroweak symmetry breaking (EWSB) in models in which the Higgs is a pseudo-Nambu-Goldstone boson (pNGB). In pNGB Higgs models, Higgs properties and precision electroweak measurements imply a hierarchy between the EWSB and global symmetry-breaking scales, $v_H \ll f_H$. When the pNGB potential is generated radiatively, this hierarchy requires fine-tuning to a degree of at least $\sim v_H^2/f_H^2$. We show that if Higgs EWSB is induced by a tadpole arising from an auxiliary sector at scale $f_\Sigma \ll v_H$, this tuning is significantly ameliorated or can even be removed. We present explicit examples both in Twin Higgs models and in Composite Higgs models based on $SO(5)/SO(4)$. For the Twin case, the result is a fully natural model with $f_H \sim 1$ TeV and the lightest colored top partners at 2 TeV. These models also have an appealing mechanism to generate the scales of the auxiliary sector and Higgs EWSB directly from the scale $f_H$, with a natural hierarchy $f_\Sigma \ll v_H \ll f_H \sim{\rm TeV}$. The framework predicts modified Higgs coupling as well as new Higgs and vector states at LHC13.
[ { "created": "Fri, 11 Mar 2016 21:00:00 GMT", "version": "v1" } ]
2017-04-26
[ [ "Harnik", "Roni", "" ], [ "Howe", "Kiel", "" ], [ "Kearney", "John", "" ] ]
We investigate induced electroweak symmetry breaking (EWSB) in models in which the Higgs is a pseudo-Nambu-Goldstone boson (pNGB). In pNGB Higgs models, Higgs properties and precision electroweak measurements imply a hierarchy between the EWSB and global symmetry-breaking scales, $v_H \ll f_H$. When the pNGB potential is generated radiatively, this hierarchy requires fine-tuning to a degree of at least $\sim v_H^2/f_H^2$. We show that if Higgs EWSB is induced by a tadpole arising from an auxiliary sector at scale $f_\Sigma \ll v_H$, this tuning is significantly ameliorated or can even be removed. We present explicit examples both in Twin Higgs models and in Composite Higgs models based on $SO(5)/SO(4)$. For the Twin case, the result is a fully natural model with $f_H \sim 1$ TeV and the lightest colored top partners at 2 TeV. These models also have an appealing mechanism to generate the scales of the auxiliary sector and Higgs EWSB directly from the scale $f_H$, with a natural hierarchy $f_\Sigma \ll v_H \ll f_H \sim{\rm TeV}$. The framework predicts modified Higgs coupling as well as new Higgs and vector states at LHC13.
hep-ph/0006074
Igor M. Suslov
I. M. Suslov (P.L.Kapitza Institute for Physical Problems, Russia)
Structure of High Order Corrections to Lipatov's Asymptotics
8 pages, ps
J.Exp.Theor.Phys. 90 (2000) 571-578; Zh.Eksp.Teor.Fiz. 117 (2000) 659-667
10.1134/1.559153
null
hep-ph cond-mat hep-th
null
High orders of perturbation theory can be calculated by the Lipatov method, whereby they are determined by saddle-point configurations (instantons) of the corresponding functional integrals. For most field theories, the Lipatov asymptotics has the functional form c a^N \Gamma(N+b) (N is the order of perturbation theory), and the relative corrections to it have a form of a series in powers of 1/N. It is shown that this series diverges factorially and its high-order coefficients can be calculated using a procedure similar to Lipatov's one. The K-th expansion coefficient has the form const(\ln(S1/S0))^{-K}\Gamma(K+(r1-r0)/2), where S0 and S1 are the values of the action for the first and the second instanton of the field theory under consideration, while r0 and r1 are the corresponding numbers of zero modes. The instantons satisfy the same equation as in the Lipatov method and are assumed to be renumbered in order of increasing of their action. This result has the universal character and is valid in any field theory for which the Lipatov asymptotic form is as specified above.
[ { "created": "Thu, 8 Jun 2000 11:58:01 GMT", "version": "v1" } ]
2009-10-31
[ [ "Suslov", "I. M.", "", "P.L.Kapitza Institute for Physical Problems, Russia" ] ]
High orders of perturbation theory can be calculated by the Lipatov method, whereby they are determined by saddle-point configurations (instantons) of the corresponding functional integrals. For most field theories, the Lipatov asymptotics has the functional form c a^N \Gamma(N+b) (N is the order of perturbation theory), and the relative corrections to it have a form of a series in powers of 1/N. It is shown that this series diverges factorially and its high-order coefficients can be calculated using a procedure similar to Lipatov's one. The K-th expansion coefficient has the form const(\ln(S1/S0))^{-K}\Gamma(K+(r1-r0)/2), where S0 and S1 are the values of the action for the first and the second instanton of the field theory under consideration, while r0 and r1 are the corresponding numbers of zero modes. The instantons satisfy the same equation as in the Lipatov method and are assumed to be renumbered in order of increasing of their action. This result has the universal character and is valid in any field theory for which the Lipatov asymptotic form is as specified above.