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hep-ph/0009210
Tri Nang Pham
Claudia Isola and T. N. Pham
Analysis of $B \to K\pi$ decays with small elastic final state interactions
LaTeX, with ReVTeX, 15 pages, 3 figures, correct header title, misprint in the abstract removed
null
null
CPHT-S 085.0900
hep-ph
null
An analysis of $B \to K\pi$ decays is given, assuming a small elastic $\pi K $ rescattering phase difference.Using factorization model only for the tree-level and electroweak penguin amplitudes, we show that the strong penguin amplitude, its absorptive part and the CP-violation weak phase $\gamma$ can be obtained from the measured $B \to K\pi$ branching ratios. The strength of the strong penguin and its absorptive part thus obtained from the CLEO data, are found to be very close to factorization model values and suggests a current $s$ quark mass around $m_{s} = 106 \rm MeV$. The central value of $\gamma$ is found to be around $76.10^{\circ}$, with a possible value in the range $50^{\circ}-100^{\circ}$.
[ { "created": "Mon, 18 Sep 2000 15:01:29 GMT", "version": "v1" }, { "created": "Tue, 19 Sep 2000 20:24:18 GMT", "version": "v2" } ]
2007-05-23
[ [ "Isola", "Claudia", "" ], [ "Pham", "T. N.", "" ] ]
An analysis of $B \to K\pi$ decays is given, assuming a small elastic $\pi K $ rescattering phase difference.Using factorization model only for the tree-level and electroweak penguin amplitudes, we show that the strong penguin amplitude, its absorptive part and the CP-violation weak phase $\gamma$ can be obtained from the measured $B \to K\pi$ branching ratios. The strength of the strong penguin and its absorptive part thus obtained from the CLEO data, are found to be very close to factorization model values and suggests a current $s$ quark mass around $m_{s} = 106 \rm MeV$. The central value of $\gamma$ is found to be around $76.10^{\circ}$, with a possible value in the range $50^{\circ}-100^{\circ}$.
hep-ph/9905357
Norma Mankoc-Borstnik
Norma Mankoc Borstnik, Holger Bech Nielsen and Colin Froggatt
What comes beyond the standard model?
Latex, 80 pages, Proceedings to the Workshop at Bled, Slovenia, 29 June - 9 July 1998. Published as a Proceedings by DMFA - Zaloznistvo, Ljubljana, Slovenia
null
null
null
hep-ph
null
The Proceedings collects the results of ten days of discussions on the open questions of the Standard electroweak model as well as the review of the introductory talks, connected with the discussions.
[ { "created": "Sun, 16 May 1999 16:47:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Borstnik", "Norma Mankoc", "" ], [ "Nielsen", "Holger Bech", "" ], [ "Froggatt", "Colin", "" ] ]
The Proceedings collects the results of ten days of discussions on the open questions of the Standard electroweak model as well as the review of the introductory talks, connected with the discussions.
0802.0669
Vadim Guzey
K. Goeke (Ruhr U., Bochum), V. Guzey (Jefferson Lab), M. Siddikov (Ruhr U., Bochum & Uzbekistan Natl. U.)
Deeply Virtual Compton Scattering on nucleons and nuclei in generalized vector meson dominance model
25 pages, 9 figures, 1 table
Eur.Phys.J.A36:49-60,2008
10.1140/epja/i2008-10549-x
JLAB-THY-08-774
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/publicdomain/
We consider Deeply Virtual Compton Scattering (DVCS) on nucleons and nuclei in the framework of generalized vector meson dominance (GVMD) model. We demonstrate that the GVMD model provides a good description of the HERA data on the dependence of the proton DVCS cross section on Q^2, W (at Q^2=4 GeV^2) and t. At Q^2 = 8 GeV^2, the soft W-behavior of the GVMD model somewhat underestimates the W-dependence of the DVCS cross section due to the hard contribution not present in the GVMD model. We estimate 1/Q^2 power-suppressed corrections to the DVCS amplitude and the DVCS cross section and find them large. We also make predictions for the nuclear DVCS amplitude and cross section in the kinematics of the future Electron-Ion Collider. We predict significant nuclear shadowing, which matches well predictions of the leading-twist nuclear shadowing in DIS on nuclei.
[ { "created": "Tue, 5 Feb 2008 17:14:55 GMT", "version": "v1" } ]
2008-11-26
[ [ "Goeke", "K.", "", "Ruhr U., Bochum" ], [ "Guzey", "V.", "", "Jefferson Lab" ], [ "Siddikov", "M.", "", "Ruhr U., Bochum & Uzbekistan Natl. U." ] ]
We consider Deeply Virtual Compton Scattering (DVCS) on nucleons and nuclei in the framework of generalized vector meson dominance (GVMD) model. We demonstrate that the GVMD model provides a good description of the HERA data on the dependence of the proton DVCS cross section on Q^2, W (at Q^2=4 GeV^2) and t. At Q^2 = 8 GeV^2, the soft W-behavior of the GVMD model somewhat underestimates the W-dependence of the DVCS cross section due to the hard contribution not present in the GVMD model. We estimate 1/Q^2 power-suppressed corrections to the DVCS amplitude and the DVCS cross section and find them large. We also make predictions for the nuclear DVCS amplitude and cross section in the kinematics of the future Electron-Ion Collider. We predict significant nuclear shadowing, which matches well predictions of the leading-twist nuclear shadowing in DIS on nuclei.
2009.04858
Guo-Li Liu
Su-Ya Bie, Guo-Li Liu, Wenyu Wang
Top Rare Decays t-> cV in the Mirror Twin Higgs Models
16 pages, 4 figures. To appear in Chin. Phys. C
null
10.1088/1674-1137/abc1d5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay t -> c V (V=\gamma, Z, g) process in the mirror twin Higgs models with the colorless top partners are studied in this paper. We found that the branching ratios of these decays can in some parameter spaces alter the standard model expectations greatly and may be detectable according to the currently precision electroweak measurements. Thus, the constraints on the model parameters may be obtained from the branching fraction of the decay processes, which may serve as a robust detection to this new physics model.
[ { "created": "Thu, 10 Sep 2020 13:43:42 GMT", "version": "v1" } ]
2021-02-03
[ [ "Bie", "Su-Ya", "" ], [ "Liu", "Guo-Li", "" ], [ "Wang", "Wenyu", "" ] ]
The decay t -> c V (V=\gamma, Z, g) process in the mirror twin Higgs models with the colorless top partners are studied in this paper. We found that the branching ratios of these decays can in some parameter spaces alter the standard model expectations greatly and may be detectable according to the currently precision electroweak measurements. Thus, the constraints on the model parameters may be obtained from the branching fraction of the decay processes, which may serve as a robust detection to this new physics model.
1202.3281
Seung-il Nam
Seung-il Nam, Chung-Wen Kao
Fragmentation and quark distribution functions for the pion and kaon with explicit flavor-SU(3)-symmetry breaking
13 pages, 16 figures
null
10.1103/PhysRevD.85.094023
KIAS-P12014; CYCU-HEP-12-01
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the unpolarized pion and kaon fragmentation functions, employing the nonlocal chiral-quark model, which manifests the nonlocal interactions between the quarks and pseudoscalar mesons, considering the explicit flavor-SU(3)-symmetry breaking in terms of the current-quark masses. Moreover, we study the quark-distribution functions, derived from the fragmentation ones with the Drell-Yan-Levi relation. Numerical results are evaluated to higher Q^2 by the DGLAP evolution and compared with the empirical data. The ratios between the relevant valance quark-distribution functions are also discussed. It turns out that the present results are in relatively good agreement with available data and other theoretical estimations.
[ { "created": "Wed, 15 Feb 2012 11:17:15 GMT", "version": "v1" } ]
2015-06-04
[ [ "Nam", "Seung-il", "" ], [ "Kao", "Chung-Wen", "" ] ]
We investigate the unpolarized pion and kaon fragmentation functions, employing the nonlocal chiral-quark model, which manifests the nonlocal interactions between the quarks and pseudoscalar mesons, considering the explicit flavor-SU(3)-symmetry breaking in terms of the current-quark masses. Moreover, we study the quark-distribution functions, derived from the fragmentation ones with the Drell-Yan-Levi relation. Numerical results are evaluated to higher Q^2 by the DGLAP evolution and compared with the empirical data. The ratios between the relevant valance quark-distribution functions are also discussed. It turns out that the present results are in relatively good agreement with available data and other theoretical estimations.
0801.0937
Tsuneo Uematsu
Yoshio Kitadono, Ken Sasaki, Takahiro Ueda and Tsuneo Uematsu
Target Mass Corrections for the Virtual Photon Structure Functions to the Next-to-next-to-leading Order in QCD
24 pages, LaTeX, 7 eps figures, REVTeX 4
Phys.Rev.D77:054019,2008
10.1103/PhysRevD.77.054019
YNU-HEPTh-07-102,KUNS-2119
hep-ph
null
We investigate target mass effects in the unpolarized virtual photon structure functions $F_2^\gamma(x,Q^2,P^2)$ and $F_L^\gamma(x,Q^2,P^2)$ in perturbative QCD for the kinematical region $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2(-P^2)$ is the mass squared of the probe (target) photon and $\Lambda$ is the QCD scale parameter. We obtain the Nachtmann moments for the structure functions and then, by inverting the moments, we get the expressions in closed form for $F_2^\gamma(x,Q^2,P^2)$ up to the next-to-next-to-leading order and for $F_L^\gamma(x,Q^2,P^2)$ up to the next-to-leading order, both of which include the target mass corrections. Numerical analysis exhibits that target mass effects appear at large $x$ and become sizable near $x_{\rm max}(=1/(1+\frac{P^2}{Q^2}))$, the maximal value of $x$, as the ratio $P^2/Q^2$ increases.
[ { "created": "Mon, 7 Jan 2008 10:16:10 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kitadono", "Yoshio", "" ], [ "Sasaki", "Ken", "" ], [ "Ueda", "Takahiro", "" ], [ "Uematsu", "Tsuneo", "" ] ]
We investigate target mass effects in the unpolarized virtual photon structure functions $F_2^\gamma(x,Q^2,P^2)$ and $F_L^\gamma(x,Q^2,P^2)$ in perturbative QCD for the kinematical region $\Lambda^2 \ll P^2 \ll Q^2$, where $-Q^2(-P^2)$ is the mass squared of the probe (target) photon and $\Lambda$ is the QCD scale parameter. We obtain the Nachtmann moments for the structure functions and then, by inverting the moments, we get the expressions in closed form for $F_2^\gamma(x,Q^2,P^2)$ up to the next-to-next-to-leading order and for $F_L^\gamma(x,Q^2,P^2)$ up to the next-to-leading order, both of which include the target mass corrections. Numerical analysis exhibits that target mass effects appear at large $x$ and become sizable near $x_{\rm max}(=1/(1+\frac{P^2}{Q^2}))$, the maximal value of $x$, as the ratio $P^2/Q^2$ increases.
1612.07479
Kazem Azizi
K. Azizi, Y. Sarac, H. Sundu
Analysis of $P_c^+(4380)$ and $P_c^+(4450)$ as pentaquark states in the molecular picture with QCD sum rules
11 Pages, 2 Figures and 2 Tables
Phys. Rev. D 95, 094016 (2017)
10.1103/PhysRevD.95.094016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To better understand the nature and internal structure of the exotic states discovered by many collaborations, more information on their electromagnetic properties and their strong and weak interactions with other hadrons is needed. The residue or current coupling constant of these states together with their mass are the main inputs in determinations of such properties. We perform QCD sum rules analyses on the hidden-charm pentaquark states with spin-parities $ J^{P}= \frac{3}{2}^{\pm}$ and $ J^{P}= \frac{5}{2}^{\pm}$ to calculate their residue and mass. In the calculations, we adopt a molecular picture for $ J^{P}= \frac{3}{2}^{\pm}$ states and a mixed current in a molecular form for $ J^{P}= \frac{5}{2}^{\pm}$. Our analyses show that the $P_c^+(4380)$ and $P_c^+(4450)$, observed by LHCb Collaboration, can be considered as hidden-charm pentaquark states with $ J^{P}= \frac{3}{2}^{-}$ and $ J^{P}= \frac{5}{2}^{+}$, respectively.
[ { "created": "Thu, 22 Dec 2016 08:09:01 GMT", "version": "v1" }, { "created": "Fri, 5 May 2017 07:21:36 GMT", "version": "v2" } ]
2017-05-31
[ [ "Azizi", "K.", "" ], [ "Sarac", "Y.", "" ], [ "Sundu", "H.", "" ] ]
To better understand the nature and internal structure of the exotic states discovered by many collaborations, more information on their electromagnetic properties and their strong and weak interactions with other hadrons is needed. The residue or current coupling constant of these states together with their mass are the main inputs in determinations of such properties. We perform QCD sum rules analyses on the hidden-charm pentaquark states with spin-parities $ J^{P}= \frac{3}{2}^{\pm}$ and $ J^{P}= \frac{5}{2}^{\pm}$ to calculate their residue and mass. In the calculations, we adopt a molecular picture for $ J^{P}= \frac{3}{2}^{\pm}$ states and a mixed current in a molecular form for $ J^{P}= \frac{5}{2}^{\pm}$. Our analyses show that the $P_c^+(4380)$ and $P_c^+(4450)$, observed by LHCb Collaboration, can be considered as hidden-charm pentaquark states with $ J^{P}= \frac{3}{2}^{-}$ and $ J^{P}= \frac{5}{2}^{+}$, respectively.
2208.05377
Wolfgang Sch\"afer
Izabela Babiarz, Roman Pasechnik, Wolfgang Sch\"afer, Antoni Szczurek
Light-front approach to axial-vector quarkonium $\gamma^* \gamma^*$ form factors
25 pages, 7 figures
null
10.1007/JHEP09(2022)170
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we perform a detailed study of transition form factors for axial-vector meson production via the two-photon fusion process $\gamma^* \gamma^* \to 1^{++}$, with space-like virtual photons in the initial state and a $P$-wave axial-vector quarkonium in the final state. In this analysis, we employ the formalism of light-front quarkonium wave functions obtained from a solution of the Schr\"odinger equation for a selection of interquark potentials for $Q \bar Q$ interaction. We found the helicity structure and covariant decomposition of the matrix elements that can be generically applied for any $q \bar q$ axial-vector meson $\gamma^* \gamma^* \to 1^{++}$ transition, while our numerical results are given for the phenomenologically relevant charmonium $\chi_{c1}$ state. We present the helicity form factors as functions of both photon virtualities. We also obtain, that $Q F_{\rm LT}(Q^2,0)/F_{\rm TT}(Q^2,0) = {\rm const.}$
[ { "created": "Wed, 10 Aug 2022 14:49:14 GMT", "version": "v1" } ]
2022-10-19
[ [ "Babiarz", "Izabela", "" ], [ "Pasechnik", "Roman", "" ], [ "Schäfer", "Wolfgang", "" ], [ "Szczurek", "Antoni", "" ] ]
In this work, we perform a detailed study of transition form factors for axial-vector meson production via the two-photon fusion process $\gamma^* \gamma^* \to 1^{++}$, with space-like virtual photons in the initial state and a $P$-wave axial-vector quarkonium in the final state. In this analysis, we employ the formalism of light-front quarkonium wave functions obtained from a solution of the Schr\"odinger equation for a selection of interquark potentials for $Q \bar Q$ interaction. We found the helicity structure and covariant decomposition of the matrix elements that can be generically applied for any $q \bar q$ axial-vector meson $\gamma^* \gamma^* \to 1^{++}$ transition, while our numerical results are given for the phenomenologically relevant charmonium $\chi_{c1}$ state. We present the helicity form factors as functions of both photon virtualities. We also obtain, that $Q F_{\rm LT}(Q^2,0)/F_{\rm TT}(Q^2,0) = {\rm const.}$
0811.0521
Dipankar Chakrabarti
D. Chakrabarti, R. Manohar, A. Mukherjee
Chiral odd GPDs in transverse and longitudinal impact parameter spaces
1 figure and references added, typos corrected. version to appear in Phys.Rev.D
Phys.Rev.D79:034006,2009
10.1103/PhysRevD.79.034006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the chiral odd generalized parton distributions (GPDs) for non-zero skewness $\zeta$ in transverse and longitudinal position spaces by taking Fourier transform with respect to the transverse and longitudinal momentum transfer respectively. We present overlap formulas for the chiral-odd GPDs in terms of light-front wave functions (LFWFs) of the proton both in the ERBL and DGLAP regions. We calculate them in a field theory inspired model of a relativistic spin 1/2 composite state with the correct correlation between the different LFWFs in Fock space, namely that of the quantum fluctuations of an electron in a generalized form of QED. We show the spin-orbit correlation effect of the two-particle LFWF as well as the correlation between the constituent spin and the transverse spin of the target.
[ { "created": "Tue, 4 Nov 2008 14:34:30 GMT", "version": "v1" }, { "created": "Wed, 4 Feb 2009 09:38:12 GMT", "version": "v2" } ]
2009-11-13
[ [ "Chakrabarti", "D.", "" ], [ "Manohar", "R.", "" ], [ "Mukherjee", "A.", "" ] ]
We investigate the chiral odd generalized parton distributions (GPDs) for non-zero skewness $\zeta$ in transverse and longitudinal position spaces by taking Fourier transform with respect to the transverse and longitudinal momentum transfer respectively. We present overlap formulas for the chiral-odd GPDs in terms of light-front wave functions (LFWFs) of the proton both in the ERBL and DGLAP regions. We calculate them in a field theory inspired model of a relativistic spin 1/2 composite state with the correct correlation between the different LFWFs in Fock space, namely that of the quantum fluctuations of an electron in a generalized form of QED. We show the spin-orbit correlation effect of the two-particle LFWF as well as the correlation between the constituent spin and the transverse spin of the target.
hep-ph/0205305
Loic Grandchamp
L. Grandchamp and R. Rapp
Charmonium Suppression and Regeneration from SPS to RHIC
17 pages, 15 figures
Nucl.Phys.A709:415-439,2002
10.1016/S0375-9474(02)01027-8
null
hep-ph nucl-th
null
The production of charmonia is investigated for heavy-ion collisions from SPS to RHIC energies. Our approach incorporates two sources of $J/\Psi$ yield: (i) a direct contribution arising from early (hard) parton-parton collisions, subject to subsequent nuclear absorption, quark-gluon plasma and hadronic dissociation, and (ii) statistical production at the hadronization transition by coalescence of $c$ and $\bar{c}$ quarks. Within an expanding thermal fireball framework, the model reproduces $J/\Psi$ centrality dependencies observed at the SPS in Pb-Pb and S-U collisions reasonably well. The study of the $\Psi'/\Psi$ ratio at SPS points at the importance of the hadronic phase for $\Psi'$ interactions, possibly related to effects of chiral symmetry restoration. Predictions are given for the centrality dependence of the $N_{J/\Psi}/N_{c\bar{c}}$ ratio at full RHIC energy. We also calculate the excitation function of this ratio. The latter exhibits a characteristic minimum structure signalling the transition from the standard $J/\Psi$ suppression scenario prevailing at SPS to dominantly thermal regeneration at collider energies.
[ { "created": "Mon, 27 May 2002 15:04:52 GMT", "version": "v1" } ]
2011-05-05
[ [ "Grandchamp", "L.", "" ], [ "Rapp", "R.", "" ] ]
The production of charmonia is investigated for heavy-ion collisions from SPS to RHIC energies. Our approach incorporates two sources of $J/\Psi$ yield: (i) a direct contribution arising from early (hard) parton-parton collisions, subject to subsequent nuclear absorption, quark-gluon plasma and hadronic dissociation, and (ii) statistical production at the hadronization transition by coalescence of $c$ and $\bar{c}$ quarks. Within an expanding thermal fireball framework, the model reproduces $J/\Psi$ centrality dependencies observed at the SPS in Pb-Pb and S-U collisions reasonably well. The study of the $\Psi'/\Psi$ ratio at SPS points at the importance of the hadronic phase for $\Psi'$ interactions, possibly related to effects of chiral symmetry restoration. Predictions are given for the centrality dependence of the $N_{J/\Psi}/N_{c\bar{c}}$ ratio at full RHIC energy. We also calculate the excitation function of this ratio. The latter exhibits a characteristic minimum structure signalling the transition from the standard $J/\Psi$ suppression scenario prevailing at SPS to dominantly thermal regeneration at collider energies.
hep-ph/9305258
John Terning
Thomas Appelquist and John Terning
Revenge of the One-Family Technicolor Models
16 pages, LaTeX
Phys.Lett. B315 (1993) 139-145
10.1016/0370-2693(93)90171-D
null
hep-ph
null
We describe how isospin splitting and techniquark-technilepton splitting in one-family technicolor models can reduce the predicted value of the electroweak radiative correction parameter S, without making a large contribution to the T parameter.
[ { "created": "Wed, 12 May 1993 19:38:31 GMT", "version": "v1" } ]
2009-10-22
[ [ "Appelquist", "Thomas", "" ], [ "Terning", "John", "" ] ]
We describe how isospin splitting and techniquark-technilepton splitting in one-family technicolor models can reduce the predicted value of the electroweak radiative correction parameter S, without making a large contribution to the T parameter.
2103.06933
Daniel Vagie
Huai-Ke Guo, Kuver Sinha, Daniel Vagie, Graham White
The Benefits of Diligence: How Precise are Predicted Gravitational Wave Spectra in Models with Phase Transitions?
43 pages, 16 figures, 1 table
JHEP06(2021)164
10.1007/JHEP06(2021)164
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models of particle physics that feature phase transitions typically provide predictions for stochastic gravitational wave signals at future detectors and such predictions are used to delineate portions of the model parameter space that can be constrained. The question is: how precise are such predictions? Uncertainties enter in the calculation of the macroscopic thermal parameters and the dynamics of the phase transition itself. We calculate such uncertainties with increasing levels of sophistication in treating the phase transition dynamics. Currently, the highest level of diligence corresponds to careful treatments of the source lifetime; mean bubble separation; going beyond the bag model approximation in solving the hydrodynamics equations and explicitly calculating the fraction of energy in the fluid from these equations rather than using a fit; and including fits for the energy lost to vorticity modes and reheating effects. The lowest level of diligence incorporates none of these effects. We compute the percolation and nucleation temperatures, the mean bubble separation, the fluid velocity, and ultimately the gravitational wave spectrum corresponding to the level of highest diligence for three explicit examples: SMEFT, a dark sector Higgs model, and the real singlet-extended Standard Model (xSM). In each model, we contrast different levels of diligence in the calculation and find that the difference in the final predicted signal can be several orders of magnitude. Our results indicate that calculating the gravitational wave spectrum for particle physics models and deducing precise constraints on the parameter space of such models continues to remain very much a work in progress and warrants care.
[ { "created": "Thu, 11 Mar 2021 20:07:36 GMT", "version": "v1" }, { "created": "Mon, 12 Jul 2021 16:13:57 GMT", "version": "v2" } ]
2021-07-13
[ [ "Guo", "Huai-Ke", "" ], [ "Sinha", "Kuver", "" ], [ "Vagie", "Daniel", "" ], [ "White", "Graham", "" ] ]
Models of particle physics that feature phase transitions typically provide predictions for stochastic gravitational wave signals at future detectors and such predictions are used to delineate portions of the model parameter space that can be constrained. The question is: how precise are such predictions? Uncertainties enter in the calculation of the macroscopic thermal parameters and the dynamics of the phase transition itself. We calculate such uncertainties with increasing levels of sophistication in treating the phase transition dynamics. Currently, the highest level of diligence corresponds to careful treatments of the source lifetime; mean bubble separation; going beyond the bag model approximation in solving the hydrodynamics equations and explicitly calculating the fraction of energy in the fluid from these equations rather than using a fit; and including fits for the energy lost to vorticity modes and reheating effects. The lowest level of diligence incorporates none of these effects. We compute the percolation and nucleation temperatures, the mean bubble separation, the fluid velocity, and ultimately the gravitational wave spectrum corresponding to the level of highest diligence for three explicit examples: SMEFT, a dark sector Higgs model, and the real singlet-extended Standard Model (xSM). In each model, we contrast different levels of diligence in the calculation and find that the difference in the final predicted signal can be several orders of magnitude. Our results indicate that calculating the gravitational wave spectrum for particle physics models and deducing precise constraints on the parameter space of such models continues to remain very much a work in progress and warrants care.
0907.3669
Hung-Ming Tsai
Hung-Ming Tsai and Berndt M\"uller
Aspects of thermal strange quark production: the deconfinement and chiral phase transitions
4 pages, 2 figures, final version - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee
Nucl.Phys.A830:551c-554c,2009
10.1016/j.nuclphysa.2009.09.045
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the gluonic sector of the three-flavor PNJL model by obtaining the adjoint Polyakov loop and the gluon distribution function in the mean-field approximation. Besides, we explore the thermal strange quark pair-production processes, $q\bar {q} \to s\bar {s}$ and $gg \to s \bar {s}$, with the aid of the three-flavor PNJL model. The results help us identify the temperature where the gluonic contribution to the production rate becomes dominant, which is an innovative phenomenon compared with the result obtained in free perturbation theory.
[ { "created": "Tue, 21 Jul 2009 19:56:34 GMT", "version": "v1" }, { "created": "Fri, 11 Sep 2009 07:13:31 GMT", "version": "v2" } ]
2009-11-18
[ [ "Tsai", "Hung-Ming", "" ], [ "Müller", "Berndt", "" ] ]
We study the gluonic sector of the three-flavor PNJL model by obtaining the adjoint Polyakov loop and the gluon distribution function in the mean-field approximation. Besides, we explore the thermal strange quark pair-production processes, $q\bar {q} \to s\bar {s}$ and $gg \to s \bar {s}$, with the aid of the three-flavor PNJL model. The results help us identify the temperature where the gluonic contribution to the production rate becomes dominant, which is an innovative phenomenon compared with the result obtained in free perturbation theory.
hep-ph/9808321
Mirjam Cvetic
Mirjam Cvetic, Lisa Everett, Jing Wang
Units and Numerical Values of the Effective Couplings in Perturbative Heterotic String Vacua
RevTeX, 8pg
Phys.Rev.D59:107901,1999
10.1103/PhysRevD.59.107901
UPR-0810-T
hep-ph hep-th
null
We determine the units and numerical values for a class of couplings in the effective theory of perturbative heterotic string vacua, with the emphasis on the correct translation between the canonical gauge coupling g and Planck scale M_Planck ~ 1.2 x 10^19 GeV as used in the effective theory description and the string coupling g_string and string tension alpha' as used in the S-matrix amplitude calculation. In particular, we determine the effective couplings in the superpotential and revisit the Fayet-Iliopoulos (FI) term in a class of models with an anomalous U(1). We derive the values of the effective Yukawa couplings (at the third and fourth order) after the restabilization of vacuum along a particular F- and D-flat direction and show that they are comparable in magnitude. The result corrects results quoted in the literature, and may have implications for the string derived phenomenology, e.g., that of fermion textures.
[ { "created": "Thu, 13 Aug 1998 22:34:26 GMT", "version": "v1" } ]
2009-09-17
[ [ "Cvetic", "Mirjam", "" ], [ "Everett", "Lisa", "" ], [ "Wang", "Jing", "" ] ]
We determine the units and numerical values for a class of couplings in the effective theory of perturbative heterotic string vacua, with the emphasis on the correct translation between the canonical gauge coupling g and Planck scale M_Planck ~ 1.2 x 10^19 GeV as used in the effective theory description and the string coupling g_string and string tension alpha' as used in the S-matrix amplitude calculation. In particular, we determine the effective couplings in the superpotential and revisit the Fayet-Iliopoulos (FI) term in a class of models with an anomalous U(1). We derive the values of the effective Yukawa couplings (at the third and fourth order) after the restabilization of vacuum along a particular F- and D-flat direction and show that they are comparable in magnitude. The result corrects results quoted in the literature, and may have implications for the string derived phenomenology, e.g., that of fermion textures.
2202.08091
Xin-Qiang Li
Fang-Min Cai, Shuichiro Funatsu, Xin-Qiang Li, and Ya-Dong Yang
Rare top-quark decays $t \to cg(g)$ in the aligned two-Higgs-doublet model
48 pages, 6 figures, and 4 tables; more references and discussions added, final version published in the journal
null
10.1140/epjc/s10052-022-10815-x
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update the Standard Model (SM) predictions for the branching ratios of the rare top-quark decays $t \to cg(g)$, and evaluate the maximum rates that can be reached in the aligned as well as in the four conventional two-Higgs-doublet models (2HDMs) with $\mathcal{Z}_2$ symmetries. Taking into account the relevant constraints on the model parameters resulting from a global fit obtained at the $95.5\%$ confidence level, we find that the branching ratios of $t \to cg$ and $t \to cgg$ decays can reach up to $3.36\times 10^{-9}$ and $2.95\times 10^{-9}$ respectively, being therefore of the same order, in the aligned 2HDM (A2HDM). This is obviously different from the SM case, where the predicted branching ratio of the three-body decay $t \to cgg$ is about two orders of magnitude larger than that of the two-body decay $t \to cg$. On the other hand, compared with the SM predictions, no significant enhancements are observed in the four conventional 2HDMs with $\mathcal{Z}_2$ symmetries for the branching ratios of these two decays. Nevertheless, the predicted branching ratios of $t \to cg$ and $t \to cgg$ decays in the A2HDM are still out of the expected sensitivities of the future high-luminosity Large Hadron Collider and the Future Circular Collider in hadron-hadron mode.
[ { "created": "Wed, 16 Feb 2022 14:24:02 GMT", "version": "v1" }, { "created": "Thu, 6 Oct 2022 09:36:42 GMT", "version": "v2" } ]
2022-10-26
[ [ "Cai", "Fang-Min", "" ], [ "Funatsu", "Shuichiro", "" ], [ "Li", "Xin-Qiang", "" ], [ "Yang", "Ya-Dong", "" ] ]
We update the Standard Model (SM) predictions for the branching ratios of the rare top-quark decays $t \to cg(g)$, and evaluate the maximum rates that can be reached in the aligned as well as in the four conventional two-Higgs-doublet models (2HDMs) with $\mathcal{Z}_2$ symmetries. Taking into account the relevant constraints on the model parameters resulting from a global fit obtained at the $95.5\%$ confidence level, we find that the branching ratios of $t \to cg$ and $t \to cgg$ decays can reach up to $3.36\times 10^{-9}$ and $2.95\times 10^{-9}$ respectively, being therefore of the same order, in the aligned 2HDM (A2HDM). This is obviously different from the SM case, where the predicted branching ratio of the three-body decay $t \to cgg$ is about two orders of magnitude larger than that of the two-body decay $t \to cg$. On the other hand, compared with the SM predictions, no significant enhancements are observed in the four conventional 2HDMs with $\mathcal{Z}_2$ symmetries for the branching ratios of these two decays. Nevertheless, the predicted branching ratios of $t \to cg$ and $t \to cgg$ decays in the A2HDM are still out of the expected sensitivities of the future high-luminosity Large Hadron Collider and the Future Circular Collider in hadron-hadron mode.
hep-ph/0201260
P. K. Das pg phy
Prasanta Das (IIT, Kanpur) and Uma Mahanta (HRI, Allahabad)
Tadpole diagrams due to KK modes of graviton and radion do not contribute to the $\rho$ parameter
Latex, 7 pages, 1 eps figure
null
null
null
hep-ph
null
In this brief report we show that tadpole diagrams due to KK modes of the graviton and radion do not contribute to the vectorial isospin breaking $\rho$ parameter. Our result is fairly general and it holds both for ADD and RS type scenarios. It shows that the difference between the results of different publications on this subject is not due to some of them not having considered tadpole diagrams in estimating the contribution to the $\rho$ parameter.
[ { "created": "Mon, 28 Jan 2002 18:06:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Das", "Prasanta", "", "IIT, Kanpur" ], [ "Mahanta", "Uma", "", "HRI, Allahabad" ] ]
In this brief report we show that tadpole diagrams due to KK modes of the graviton and radion do not contribute to the vectorial isospin breaking $\rho$ parameter. Our result is fairly general and it holds both for ADD and RS type scenarios. It shows that the difference between the results of different publications on this subject is not due to some of them not having considered tadpole diagrams in estimating the contribution to the $\rho$ parameter.
hep-ph/0112063
Gustavo Burdman
Gustavo Burdman
Rare B decays beyond B-> Xs gamma
11 pages, 2 ps figures. Invited talk at Heavy Flavors 9, Caltech, Pasadena, Sept. 10-13 2001
AIP Conf.Proc. 618 (2002) 169-179
10.1063/1.1478834
null
hep-ph
null
I discuss recent progress in our understanding of exclusive rare and semileptonic decays. I show the impact of HQET when combined with the predictions in the Large Energy Limit of QCD, focusing first on applications to $B\to K^*\ell^+\ell^+$. I also discuss the constraints on semileptonic form-factors that appear in HQET/LEET with the use of radiative decay data, and update these to include the effects of next-to-leading order contributions in $B\to K^*\gamma$, as well as the latest data.
[ { "created": "Tue, 4 Dec 2001 22:14:37 GMT", "version": "v1" } ]
2009-11-07
[ [ "Burdman", "Gustavo", "" ] ]
I discuss recent progress in our understanding of exclusive rare and semileptonic decays. I show the impact of HQET when combined with the predictions in the Large Energy Limit of QCD, focusing first on applications to $B\to K^*\ell^+\ell^+$. I also discuss the constraints on semileptonic form-factors that appear in HQET/LEET with the use of radiative decay data, and update these to include the effects of next-to-leading order contributions in $B\to K^*\gamma$, as well as the latest data.
1609.03445
Mahdi Ahmadian Shalchi
M. A. Shalchi, M. R. Hadizadeh
R-Matrix Calculations for Few-Quark Bound States
null
Eur. Phys. J. C (2016) 76: 522
10.1140/epjc/s10052-016-4369-1
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The R--matrix method is implemented to study the heavy charm and bottom diquark, triquark, tetraquark and pentaquarks in configuration space, as the bound states of quark--antiquark, diquark--quark, diquark--antidiquark and diquark--antitriquark systems, respectively. The mass spectrum and the size of these systems are calculated for different partial wave channels. The calculated masses are compared with recent theoretical results obtained by other methods in momentum and configuration spaces and also by available experimental data.
[ { "created": "Mon, 12 Sep 2016 15:21:41 GMT", "version": "v1" }, { "created": "Fri, 30 Sep 2016 21:09:27 GMT", "version": "v2" } ]
2016-10-04
[ [ "Shalchi", "M. A.", "" ], [ "Hadizadeh", "M. R.", "" ] ]
The R--matrix method is implemented to study the heavy charm and bottom diquark, triquark, tetraquark and pentaquarks in configuration space, as the bound states of quark--antiquark, diquark--quark, diquark--antidiquark and diquark--antitriquark systems, respectively. The mass spectrum and the size of these systems are calculated for different partial wave channels. The calculated masses are compared with recent theoretical results obtained by other methods in momentum and configuration spaces and also by available experimental data.
1006.1947
Henry Tsz-King Wong
M. Deniz er al., TEXONO Collaboration
Constraints on Non-Standard Neutrino Interactions and Unparticle Physics with Neutrino-Electron Scattering at the Kuo-Sheng Nuclear Power Reactor
8 pages, 6 figures, 1 table ; Published Version in V2 with minor revisions
Phys.Rev.D82:033004,2010
10.1103/PhysRevD.82.033004
AS-TEXONO/10-03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino-electron scatterings are purely leptonic processes with robust Standard Model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. The $\nuebar$-e data taken at the Kuo-Sheng Reactor Neutrino Laboratory were used to probe two scenarios: Non-Standard Neutrino Interactions (NSI) and Unparticle Physics. New constraints were placed to the NSI parameters ($\el$,$\er$) and ($\etl$,$\etr$) for the Non-Universal and Flavor-Changing channels, respectively, as well as to the coupling constants for scalar ($\lambda_0$) and vector ($\lambda_1$) unparticles to the neutrinos and electrons.
[ { "created": "Thu, 10 Jun 2010 04:56:01 GMT", "version": "v1" }, { "created": "Mon, 9 Aug 2010 06:12:02 GMT", "version": "v2" } ]
2014-11-21
[ [ "al.", "M. Deniz er", "" ], [ "Collaboration", "TEXONO", "" ] ]
Neutrino-electron scatterings are purely leptonic processes with robust Standard Model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. The $\nuebar$-e data taken at the Kuo-Sheng Reactor Neutrino Laboratory were used to probe two scenarios: Non-Standard Neutrino Interactions (NSI) and Unparticle Physics. New constraints were placed to the NSI parameters ($\el$,$\er$) and ($\etl$,$\etr$) for the Non-Universal and Flavor-Changing channels, respectively, as well as to the coupling constants for scalar ($\lambda_0$) and vector ($\lambda_1$) unparticles to the neutrinos and electrons.
1610.07606
Anthony DiFranzo
Anthony DiFranzo and Gopolang Mohlabeng
Multi-component Dark Matter through a Radiative Higgs Portal
22 pages, 9 figures, published version, updated text and references
J. High Energ. Phys. (2017) 2017: 80
10.1007/JHEP01(2017)080
FERMILAB-PUB-16-456-T, UCI-HEP-TR-2016-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a multi-component dark matter model where interactions with the Standard Model are primarily via the Higgs boson. The model contains vector-like fermions charged under $SU(2)_W \times U(1)_Y$ and under the dark gauge group, $U(1)^\prime$. This results in two dark matter candidates. A spin-1 and a spin-1/2 candidate, which have loop and tree-level couplings to the Higgs, respectively. We explore the resulting effect on the dark matter relic abundance, while also evaluating constraints on the Higgs invisible width and from direct detection experiments. Generally, we find that this model is highly constrained when the fermionic candidate is the predominant fraction of the dark matter relic abundance.
[ { "created": "Mon, 24 Oct 2016 20:00:00 GMT", "version": "v1" }, { "created": "Mon, 23 Jan 2017 21:11:59 GMT", "version": "v2" } ]
2017-01-25
[ [ "DiFranzo", "Anthony", "" ], [ "Mohlabeng", "Gopolang", "" ] ]
We study a multi-component dark matter model where interactions with the Standard Model are primarily via the Higgs boson. The model contains vector-like fermions charged under $SU(2)_W \times U(1)_Y$ and under the dark gauge group, $U(1)^\prime$. This results in two dark matter candidates. A spin-1 and a spin-1/2 candidate, which have loop and tree-level couplings to the Higgs, respectively. We explore the resulting effect on the dark matter relic abundance, while also evaluating constraints on the Higgs invisible width and from direct detection experiments. Generally, we find that this model is highly constrained when the fermionic candidate is the predominant fraction of the dark matter relic abundance.
1201.6337
Franz Gross
Franz Gross, G. Ramalho and M. T. Pena
Spin and angular momentum in the nucleon
27 pages; 13 figures
Phys. Rev. D 85, 093006 (2012) [27 pages]
10.1103/PhysRevD.85.093006
JLAB-THY-12-1489
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the covariant spectator theory (CST), we present the results of a valence quark-diquark model calculation of the nucleon structure function f(x) measured in unpolarized deep inelastic scattering (DIS), and the structure functions g1(x) and g2(x) measured in DIS using polarized beams and targets. Parameters of the wave functions are adjusted to fit all the data. The fit fixes both the shape of the wave functions and the relative strength of each component. Two solutions are found that fit f(x) and g1(x), but only one of these gives a good description of g2(x). This fit requires the nucleon CST wave functions contain a large D-wave component (about 35%) and a small P-wave component (about 0.6%). The significance of these results is discussed.
[ { "created": "Mon, 30 Jan 2012 20:15:51 GMT", "version": "v1" } ]
2012-05-24
[ [ "Gross", "Franz", "" ], [ "Ramalho", "G.", "" ], [ "Pena", "M. T.", "" ] ]
Using the covariant spectator theory (CST), we present the results of a valence quark-diquark model calculation of the nucleon structure function f(x) measured in unpolarized deep inelastic scattering (DIS), and the structure functions g1(x) and g2(x) measured in DIS using polarized beams and targets. Parameters of the wave functions are adjusted to fit all the data. The fit fixes both the shape of the wave functions and the relative strength of each component. Two solutions are found that fit f(x) and g1(x), but only one of these gives a good description of g2(x). This fit requires the nucleon CST wave functions contain a large D-wave component (about 35%) and a small P-wave component (about 0.6%). The significance of these results is discussed.
1510.08462
Zhengkang Zhang
James D. Wells and Zhengkang Zhang
Effective theories of universal theories
40 pages + appendix and references, 8 tables
null
10.1007/JHEP01(2016)123
MCTP-15-24
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well-known but sometimes overlooked that constraints on the oblique parameters (most notably $S$ and $T$ parameters) are generally speaking only applicable to a special class of new physics scenarios known as universal theories. In the effective field theory (EFT) framework, the oblique parameters should not be associated with Wilson coefficients in a particular operator basis, unless restrictions have been imposed on the EFT so that it describes universal theories. We work out these restrictions, and present a detailed EFT analysis of universal theories. We find that at the dimension-6 level, universal theories are completely characterized by 16 parameters. They are conveniently chosen to be: 5 oblique parameters that agree with the commonly-adopted ones, 4 anomalous triple-gauge couplings, 3 rescaling factors for the $h^3$, $hff$, $hVV$ vertices, 3 parameters for $hVV$ vertices absent in the Standard Model, and 1 four-fermion coupling of order $y_f^2$. All these parameters are defined in an unambiguous and basis-independent way, allowing for consistent constraints on the universal theories parameter space from precision electroweak and Higgs data.
[ { "created": "Wed, 28 Oct 2015 20:08:44 GMT", "version": "v1" }, { "created": "Thu, 19 Nov 2015 18:29:41 GMT", "version": "v2" } ]
2016-02-17
[ [ "Wells", "James D.", "" ], [ "Zhang", "Zhengkang", "" ] ]
It is well-known but sometimes overlooked that constraints on the oblique parameters (most notably $S$ and $T$ parameters) are generally speaking only applicable to a special class of new physics scenarios known as universal theories. In the effective field theory (EFT) framework, the oblique parameters should not be associated with Wilson coefficients in a particular operator basis, unless restrictions have been imposed on the EFT so that it describes universal theories. We work out these restrictions, and present a detailed EFT analysis of universal theories. We find that at the dimension-6 level, universal theories are completely characterized by 16 parameters. They are conveniently chosen to be: 5 oblique parameters that agree with the commonly-adopted ones, 4 anomalous triple-gauge couplings, 3 rescaling factors for the $h^3$, $hff$, $hVV$ vertices, 3 parameters for $hVV$ vertices absent in the Standard Model, and 1 four-fermion coupling of order $y_f^2$. All these parameters are defined in an unambiguous and basis-independent way, allowing for consistent constraints on the universal theories parameter space from precision electroweak and Higgs data.
hep-ph/9311224
null
A.C. Pearson
Why the real time formalism doesn't factorise
7 pages, Imperial/TP/93-94/7
null
null
null
hep-ph
null
We show that in the real time formalism, the generating functional for thermal Green functions does not factorise. However for most calculations, the normal real time Feynman rules can still be used to give correct results.
[ { "created": "Thu, 4 Nov 1993 14:35:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pearson", "A. C.", "" ] ]
We show that in the real time formalism, the generating functional for thermal Green functions does not factorise. However for most calculations, the normal real time Feynman rules can still be used to give correct results.
hep-ph/0101201
Chuan Hung Chen
Chuan-Hung Chen and C.Q. Geng
Lepton Asymmetries in Heavy Baryon Decays of $\Lambda_b\to\Lambda l^+l^-$
10 pages, 9 figures, revised version
Phys.Lett. B516 (2001) 327-336
10.1016/S0370-2693(01)00937-6
null
hep-ph
null
We study the dilepton forward-backward and the longitudinal, normal and transverse lepton polarization asymmetries in the heavy baryon decays of $\Lambda_b\to\Lambda l^+l^-$. We show that the asymmetries have a less dependence on the non-perturbative QCD effects. In the standard model, we find that the integrated forward-backward asymmetries (FBAs) and three components of the polarizations in the QCD sum rule approach (pole model) are $-0.13\ (-0.12)$ and $(58.3,-9.4,-0.07)%$ ($(58.3,-12.6,-0.07)%$) for $\Lambda_b\to\Lambda\mu^+\mu^-$ and $-0.04 (-0.03)$ and $(10.9,-10.0,-0.39)%$ ($(10.9,-0.2,-0.34)%$) for $\Lambda_b\to\Lambda\tau^+\tau^-$, respectively.
[ { "created": "Thu, 18 Jan 2001 03:35:34 GMT", "version": "v1" }, { "created": "Mon, 19 Mar 2001 10:11:21 GMT", "version": "v2" } ]
2010-06-02
[ [ "Chen", "Chuan-Hung", "" ], [ "Geng", "C. Q.", "" ] ]
We study the dilepton forward-backward and the longitudinal, normal and transverse lepton polarization asymmetries in the heavy baryon decays of $\Lambda_b\to\Lambda l^+l^-$. We show that the asymmetries have a less dependence on the non-perturbative QCD effects. In the standard model, we find that the integrated forward-backward asymmetries (FBAs) and three components of the polarizations in the QCD sum rule approach (pole model) are $-0.13\ (-0.12)$ and $(58.3,-9.4,-0.07)%$ ($(58.3,-12.6,-0.07)%$) for $\Lambda_b\to\Lambda\mu^+\mu^-$ and $-0.04 (-0.03)$ and $(10.9,-10.0,-0.39)%$ ($(10.9,-0.2,-0.34)%$) for $\Lambda_b\to\Lambda\tau^+\tau^-$, respectively.
2305.00013
Ian Lewis
Samuel D. Lane, Hye-Sung Lee, Ian M. Lewis
Multi-photon decays of the Higgs boson at the LHC
23 pages, 12 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many new physics scenarios predict multi-photon Higgs resonances. One such scenario is the dark axion portal model. The primary decay chain that we study is the Higgs to dark photon ($\gamma_D$) pairs that subsequently decay into a photon ($\gamma$) and an axion-like particle ($a$). The axion-like particles then decay into photon pairs. Hence, the signal is a six-photon Higgs decay: $h\rightarrow \gamma_D\,\gamma_D\rightarrow 2\,\gamma 2\,a\rightarrow 6\gamma$. However, depending on the relevant kinematics, the photons can become well-collimated and appear as photon-jets (multiple photons that appear as a single photon in the detector) or $\xi$-jets (non-isolated multi-photon signals that do not pass the isolation criterion). These effects cause the true six-photon resonance to appear as other multi-photon signals, such as two and four photons. We classify the mass regions where two, four, and six-photon resonances dominate. The four-photon signal is particularly interesting. These events mainly occur when the photons from the axion-like particles are collimated into photon-jets. The decay of the dark photon is then $\gamma_D\rightarrow \gamma a\rightarrow \gamma+\gamma$-jet, which is an apparent violation of the Landau-Yang theorem. We show that current measurements of $h\rightarrow 2\gamma$ and searches for $h\rightarrow 4\gamma$ at the Large Hadron Collider (LHC) can limit ${\rm BR}(h\rightarrow \gamma_D\gamma_D)\lesssim 10^{-3}$. This model also motivates new searches for Higgs decays into six isolated photons or $\xi$-jets at the LHC. While there are currently no dedicated searches, we show that many of the Higgs to six isolated photons or $\xi$-jet events could pass two or three-photon triggers. That is, new physics could be found by reanalyzing existing data. These multi-photon signals provide excellent footing to explore new physics at the LHC and beyond.
[ { "created": "Fri, 28 Apr 2023 18:00:00 GMT", "version": "v1" } ]
2023-05-02
[ [ "Lane", "Samuel D.", "" ], [ "Lee", "Hye-Sung", "" ], [ "Lewis", "Ian M.", "" ] ]
Many new physics scenarios predict multi-photon Higgs resonances. One such scenario is the dark axion portal model. The primary decay chain that we study is the Higgs to dark photon ($\gamma_D$) pairs that subsequently decay into a photon ($\gamma$) and an axion-like particle ($a$). The axion-like particles then decay into photon pairs. Hence, the signal is a six-photon Higgs decay: $h\rightarrow \gamma_D\,\gamma_D\rightarrow 2\,\gamma 2\,a\rightarrow 6\gamma$. However, depending on the relevant kinematics, the photons can become well-collimated and appear as photon-jets (multiple photons that appear as a single photon in the detector) or $\xi$-jets (non-isolated multi-photon signals that do not pass the isolation criterion). These effects cause the true six-photon resonance to appear as other multi-photon signals, such as two and four photons. We classify the mass regions where two, four, and six-photon resonances dominate. The four-photon signal is particularly interesting. These events mainly occur when the photons from the axion-like particles are collimated into photon-jets. The decay of the dark photon is then $\gamma_D\rightarrow \gamma a\rightarrow \gamma+\gamma$-jet, which is an apparent violation of the Landau-Yang theorem. We show that current measurements of $h\rightarrow 2\gamma$ and searches for $h\rightarrow 4\gamma$ at the Large Hadron Collider (LHC) can limit ${\rm BR}(h\rightarrow \gamma_D\gamma_D)\lesssim 10^{-3}$. This model also motivates new searches for Higgs decays into six isolated photons or $\xi$-jets at the LHC. While there are currently no dedicated searches, we show that many of the Higgs to six isolated photons or $\xi$-jet events could pass two or three-photon triggers. That is, new physics could be found by reanalyzing existing data. These multi-photon signals provide excellent footing to explore new physics at the LHC and beyond.
hep-ph/0607285
Manuel Toharia
Brooks Thomas and Manuel Toharia
Lepton Flavor Violation and Supersymmetric Dirac Leptogenesis
15 pages, 4 figures, corrected parametric dependance on leading LFV term, figure 2 and discussion modified accordingly, conclusions unchanged
Phys.Rev.D75:013013,2007
10.1103/PhysRevD.75.013013
MCTP-06-17
hep-ph
null
Dirac leptogenesis (or Dirac neutrinogenesis), in which neutrinos are purely Dirac particles, is an interesting alternative to the standard leptogenesis scenario. In its supersymmetric version, the modified form of the superpotential required for successful baryogenesis contributes new, generically non-flavor-diagonal terms to the slepton and sneutrino mass matrices. In this work, we examine how current experimental bounds on flavor-changing effects in the lepton sector (and particularly the bound on Mu -> e Gamma) constrain Dirac leptogenesis and we find that it is capable of succeeding with superpartner masses as low as 100 GeV. For such light scalars and electroweakinos, upcoming experiments such as MEG are generically expected to observe signals of lepton flavor violation.
[ { "created": "Wed, 26 Jul 2006 02:56:54 GMT", "version": "v1" }, { "created": "Tue, 29 Aug 2006 01:33:29 GMT", "version": "v2" } ]
2008-11-26
[ [ "Thomas", "Brooks", "" ], [ "Toharia", "Manuel", "" ] ]
Dirac leptogenesis (or Dirac neutrinogenesis), in which neutrinos are purely Dirac particles, is an interesting alternative to the standard leptogenesis scenario. In its supersymmetric version, the modified form of the superpotential required for successful baryogenesis contributes new, generically non-flavor-diagonal terms to the slepton and sneutrino mass matrices. In this work, we examine how current experimental bounds on flavor-changing effects in the lepton sector (and particularly the bound on Mu -> e Gamma) constrain Dirac leptogenesis and we find that it is capable of succeeding with superpartner masses as low as 100 GeV. For such light scalars and electroweakinos, upcoming experiments such as MEG are generically expected to observe signals of lepton flavor violation.
0802.0171
Bernd Kniehl
Joachim Brod, Frank Fugel, and Bernd A. Kniehl
Dominant two-loop electroweak corrections to the hadroproduction of a pseudoscalar Higgs boson and its photonic decay
9 pages, 3 figures
Phys.Rev.D78:011303,2008
10.1103/PhysRevD.78.011303
DESY 08-010, TTP08-05, SFB/CPP-08-10
hep-ph
null
We present the dominant two-loop electroweak corrections to the partial decay widths to gluon jets and prompt photons of the neutral CP-odd Higgs boson A^0, with mass M_{A^0} < 2 M_W, in the two-Higgs-doublet model for low to intermediate values of the ratio tan(beta) = v_2/v_1 of the vacuum expectation values. They apply as they stand to the production cross sections in hadronic and two-photon collisions, at the Tevatron, the LHC, and a future photon collider. The appearance of three gamma_5 matrices in closed fermion loops requires special care in the dimensional regularization of ultraviolet divergences. The corrections are negative and amount to several percent, so that they fully compensate or partly screen the enhancement due to QCD corrections.
[ { "created": "Fri, 1 Feb 2008 17:27:20 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brod", "Joachim", "" ], [ "Fugel", "Frank", "" ], [ "Kniehl", "Bernd A.", "" ] ]
We present the dominant two-loop electroweak corrections to the partial decay widths to gluon jets and prompt photons of the neutral CP-odd Higgs boson A^0, with mass M_{A^0} < 2 M_W, in the two-Higgs-doublet model for low to intermediate values of the ratio tan(beta) = v_2/v_1 of the vacuum expectation values. They apply as they stand to the production cross sections in hadronic and two-photon collisions, at the Tevatron, the LHC, and a future photon collider. The appearance of three gamma_5 matrices in closed fermion loops requires special care in the dimensional regularization of ultraviolet divergences. The corrections are negative and amount to several percent, so that they fully compensate or partly screen the enhancement due to QCD corrections.
1602.08212
Albino Hernandez-Galeana
Albino Hernandez-Galeana
Charged Fermion Masses and Mixing from a SU(3) Family Symmetry Model
LaTex 14 pages, 1 figure. Contribution to Proceedings to the 18th Bled workshop "What comes beyond the standard models.", 11-19 July, 2015, Bled, Slovenia. version with minor improvements and corrections. arXiv admin note: substantial text overlap with arXiv:1212.4571, arXiv:1312.3403
Bled Workshops in Physics, Vol.16, No. 2, (2015) 47-62. ( ISSN: 1580-4992 )
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the framework of a Beyond Standard Model (BSM) with a local $SU(3)$ family symmetry, we report an updated fit of parameters which account for the known spectrum of quarks and charged lepton masses and the quark mixing in a $4\times 4$ non-unitary $V_{CKM}$. In this scenario, ordinary heavy fermions, top and bottom quarks and tau lepton, become massive at tree level from Dirac See-saw mechanisms implemented by the introduction of a new set of $SU(2)_L$ weak singlet vector-like fermions, $U,D,E,N$, with $N$ a sterile neutrino. The $N_{L,R}$ sterile neutrinos allow the implementation of a $8\times 8$ general See-saw Majorana neutrino mass matrix with four massless eigenvalues at tree level. Hence, light fermions, including neutrinos, obtain masses from loop radiative corrections mediated by the massive $SU(3)$ gauge bosons. $SU(3)$ family symmetry is broken spontaneously in two stages, whose hierarchy of scales yield an approximate $SU(2)$ global symmetry associated with the $Z_1, Y_1^\pm$ gauge boson masses of the order of 2 TeV. A global fit of parameters to include neutrino masses and lepton mixing is in progress.
[ { "created": "Fri, 26 Feb 2016 06:35:05 GMT", "version": "v1" } ]
2016-02-29
[ [ "Hernandez-Galeana", "Albino", "" ] ]
Within the framework of a Beyond Standard Model (BSM) with a local $SU(3)$ family symmetry, we report an updated fit of parameters which account for the known spectrum of quarks and charged lepton masses and the quark mixing in a $4\times 4$ non-unitary $V_{CKM}$. In this scenario, ordinary heavy fermions, top and bottom quarks and tau lepton, become massive at tree level from Dirac See-saw mechanisms implemented by the introduction of a new set of $SU(2)_L$ weak singlet vector-like fermions, $U,D,E,N$, with $N$ a sterile neutrino. The $N_{L,R}$ sterile neutrinos allow the implementation of a $8\times 8$ general See-saw Majorana neutrino mass matrix with four massless eigenvalues at tree level. Hence, light fermions, including neutrinos, obtain masses from loop radiative corrections mediated by the massive $SU(3)$ gauge bosons. $SU(3)$ family symmetry is broken spontaneously in two stages, whose hierarchy of scales yield an approximate $SU(2)$ global symmetry associated with the $Z_1, Y_1^\pm$ gauge boson masses of the order of 2 TeV. A global fit of parameters to include neutrino masses and lepton mixing is in progress.
2108.10035
Siamak Sadat Gousheh
S. Abbaslu, S. Rostam Zadeh and S. S. Gousheh
Contribution of the thermal mass to the chiral vortical effect and magnetobaryogenesis
28 pages, 2 figures, 4 tables, 4 Appendices
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the chiral vortical effect can exist in a nonchiral electroweak plasma in thermal equilibrium using the effective thermal masses of the fermions in the symmetric phase. We use a nonperturbative formula for the vortical current, which has been recently obtained and is a functional of the dispersion relation. Then, taking into account the effect of fermion thermal mass in the dispersion relation, we show that the corresponding hyperelectric vortical current receives implicit thermal corrections proportional to T2, from both the gauge and Yukawa interactions of the fermion. We show that the contributions of gauge interactions to the thermal masses in the total hyperelectric vortical current cancel out due to the gauge symmetries, while those of the Yukawa interactions do not cancel out. We finally show that, due to this current, only small transient vorticity fluctuations about the zero background value in a nonchiral electroweak plasma in thermal equilibrium can activate the chiral vortical effect, leading to the generation of hypermagnetic fields and matter-antimatter asymmetries in the symmetric phase of the early Universe, in the temperature range 100GeV<T<10TeV, all starting from zero initial values, even in the presence of the weak sphaleron processes.
[ { "created": "Mon, 23 Aug 2021 09:51:01 GMT", "version": "v1" }, { "created": "Fri, 8 Jul 2022 18:01:34 GMT", "version": "v2" }, { "created": "Sun, 27 Aug 2023 14:40:06 GMT", "version": "v3" } ]
2023-08-29
[ [ "Abbaslu", "S.", "" ], [ "Zadeh", "S. Rostam", "" ], [ "Gousheh", "S. S.", "" ] ]
We show that the chiral vortical effect can exist in a nonchiral electroweak plasma in thermal equilibrium using the effective thermal masses of the fermions in the symmetric phase. We use a nonperturbative formula for the vortical current, which has been recently obtained and is a functional of the dispersion relation. Then, taking into account the effect of fermion thermal mass in the dispersion relation, we show that the corresponding hyperelectric vortical current receives implicit thermal corrections proportional to T2, from both the gauge and Yukawa interactions of the fermion. We show that the contributions of gauge interactions to the thermal masses in the total hyperelectric vortical current cancel out due to the gauge symmetries, while those of the Yukawa interactions do not cancel out. We finally show that, due to this current, only small transient vorticity fluctuations about the zero background value in a nonchiral electroweak plasma in thermal equilibrium can activate the chiral vortical effect, leading to the generation of hypermagnetic fields and matter-antimatter asymmetries in the symmetric phase of the early Universe, in the temperature range 100GeV<T<10TeV, all starting from zero initial values, even in the presence of the weak sphaleron processes.
0908.3581
Ayse Cagil
Ayse Cagil, Mehmet T. Zeyrek
$Z_L$ associated pair production of charged Higgs bosons in the littlest Higgs model at $e^{+}e^{-}$ colliders
20 pages, 5 figures, version published in Physical Review D
Phys.Rev.D80:055021,2009
10.1103/PhysRevD.80.055021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of single and doubly charged Higgs bosons associated with standard model gauge boson $Z_L$ in $e^{+}e^{-}$ colliders are examined. The sensitivity of these processes on the littlest Higgs model parameters in the range of compatibility with electroweak precision observables are analyzed. The possibility of detecting lepton flavor violation processes are also discussed.
[ { "created": "Tue, 25 Aug 2009 10:07:20 GMT", "version": "v1" }, { "created": "Mon, 12 Mar 2012 12:46:43 GMT", "version": "v2" } ]
2012-03-13
[ [ "Cagil", "Ayse", "" ], [ "Zeyrek", "Mehmet T.", "" ] ]
The production of single and doubly charged Higgs bosons associated with standard model gauge boson $Z_L$ in $e^{+}e^{-}$ colliders are examined. The sensitivity of these processes on the littlest Higgs model parameters in the range of compatibility with electroweak precision observables are analyzed. The possibility of detecting lepton flavor violation processes are also discussed.
hep-ph/0701032
Harry Lipkin J
Harry J. Lipkin
From Sakata Model to Goldberg-Ne'eman Quarks and Nambu QCD Phenomenology and "Right" and "Wrong" experiments
8 pages
Prog.Theor.Phys.Suppl.167:155-162,2007
10.1143/PTPS.167.155
null
hep-ph
null
The basic theoretical milestones were the Sakata SU(3) symmetry, the Goldberg-Ne'eman composite model with SU(3) triplets having baryon number (1/3) and the Nambu color gauge Lagrangian. The transition was led in right and wrong directions by experiments interpreted by phenomenology. A "good" experiment on $\bar p p$ annihilation at rest showed that the Sakata model predictions disagreed with experiment. A "bad" experiment prevented the use of the Goldberg-Ne'eman triplet model to predict the existence and masses of the of the $\Xi^*$ and $\Omega^-$. More "good" experiments revealed the existence and mass of the $\Xi^*$ and the $\Omega^-$ and the absence of positive strangeness baryon resonances, thus confirming the "tenfold way". Further "good experiments" revealed the existence of the vector meson nonet, SU(3) breaking with singlet-octet mixing and the suppression of the $\phi \to \rho \pi$ decay. These led to the quark triplet model. The paradox of peculiar statistics then arose as the $\Delta^{++}$ and $\Omega^-$ contained three identical spin-1/2 fermions coupled symmetrically to spin (3/2). This led to color and the Nambu QCD. The book "Lie Groups for Pedestrians" used the Sakata model with the name "sakaton" for the $pn\Lambda$ triplet to teach the algebra of SU(3) to particle physicists in the U.S. and Europe who knew no group theory. The Sakata model had a renaissance in hypernuclear physics in the 1970's.
[ { "created": "Thu, 4 Jan 2007 18:08:42 GMT", "version": "v1" }, { "created": "Wed, 31 Jan 2007 14:52:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lipkin", "Harry J.", "" ] ]
The basic theoretical milestones were the Sakata SU(3) symmetry, the Goldberg-Ne'eman composite model with SU(3) triplets having baryon number (1/3) and the Nambu color gauge Lagrangian. The transition was led in right and wrong directions by experiments interpreted by phenomenology. A "good" experiment on $\bar p p$ annihilation at rest showed that the Sakata model predictions disagreed with experiment. A "bad" experiment prevented the use of the Goldberg-Ne'eman triplet model to predict the existence and masses of the of the $\Xi^*$ and $\Omega^-$. More "good" experiments revealed the existence and mass of the $\Xi^*$ and the $\Omega^-$ and the absence of positive strangeness baryon resonances, thus confirming the "tenfold way". Further "good experiments" revealed the existence of the vector meson nonet, SU(3) breaking with singlet-octet mixing and the suppression of the $\phi \to \rho \pi$ decay. These led to the quark triplet model. The paradox of peculiar statistics then arose as the $\Delta^{++}$ and $\Omega^-$ contained three identical spin-1/2 fermions coupled symmetrically to spin (3/2). This led to color and the Nambu QCD. The book "Lie Groups for Pedestrians" used the Sakata model with the name "sakaton" for the $pn\Lambda$ triplet to teach the algebra of SU(3) to particle physicists in the U.S. and Europe who knew no group theory. The Sakata model had a renaissance in hypernuclear physics in the 1970's.
hep-ph/0601090
Chris Bird
C. Bird, R. Kowalewski, M. Pospelov
Dark matter pair-production in b -> s transitions
23 pages, 11 figures,Invited Review for MPLA; Corrected minor typos, added two references
Mod.Phys.Lett.A21:457-478,2006
10.1142/S0217732306019852
UVIC-TH/06-01
hep-ph
null
The flavour-changing neutral current transition b \to s can serve as a sensitive probe of WIMP dark matter models, if the WIMP mass is under 2 GeV. In this work we extend our earlier analysis to a generic class of models where the interaction between the dark matter sector and the Standard Model matter sector is mediated by the Higgs boson(s). We show that experimental limits on the decays of B-mesons to K(K^*) and missing energy provide stringent constraints on the parameter space of such models, but do not rule out sub-GeV WIMPs in a model-independent way. We find that in the context of the NMSSM with light pseudoscalar Higgs, the WIMP masses under a few hundred MeV are generically excluded with the exception of few highly tuned points in the parameter space.
[ { "created": "Thu, 12 Jan 2006 06:55:04 GMT", "version": "v1" }, { "created": "Sun, 5 Mar 2006 05:06:14 GMT", "version": "v2" } ]
2009-11-11
[ [ "Bird", "C.", "" ], [ "Kowalewski", "R.", "" ], [ "Pospelov", "M.", "" ] ]
The flavour-changing neutral current transition b \to s can serve as a sensitive probe of WIMP dark matter models, if the WIMP mass is under 2 GeV. In this work we extend our earlier analysis to a generic class of models where the interaction between the dark matter sector and the Standard Model matter sector is mediated by the Higgs boson(s). We show that experimental limits on the decays of B-mesons to K(K^*) and missing energy provide stringent constraints on the parameter space of such models, but do not rule out sub-GeV WIMPs in a model-independent way. We find that in the context of the NMSSM with light pseudoscalar Higgs, the WIMP masses under a few hundred MeV are generically excluded with the exception of few highly tuned points in the parameter space.
1506.05042
Fernando M\'endez
J. Gamboa and F. Mendez
Dark and Visible Photons as Source of CP Violation
4 pages, no figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of excess gamma radiation in the center of galaxy is discussed assuming that the photon's production is dominated by two kinds of processes, the first one due to the conventional kinetic mixing term and, secondly, due to a kinetic mixing term violating the CP symmetry between dark and visible photons. The CP violation symmetry between dark and visible sectors is not forbidden and, in principle, could be considered as an additional source of CP violation. The conversion probability between dark and visible photons is calculated and compared between both processes. The processes violating CP are less significant but contribute non-trivially to the excess gamma radiation.
[ { "created": "Tue, 16 Jun 2015 17:34:26 GMT", "version": "v1" } ]
2015-06-17
[ [ "Gamboa", "J.", "" ], [ "Mendez", "F.", "" ] ]
The problem of excess gamma radiation in the center of galaxy is discussed assuming that the photon's production is dominated by two kinds of processes, the first one due to the conventional kinetic mixing term and, secondly, due to a kinetic mixing term violating the CP symmetry between dark and visible photons. The CP violation symmetry between dark and visible sectors is not forbidden and, in principle, could be considered as an additional source of CP violation. The conversion probability between dark and visible photons is calculated and compared between both processes. The processes violating CP are less significant but contribute non-trivially to the excess gamma radiation.
1407.3792
Roman Kogler
M. Baak, J. Cuth, J. Haller, A. Hoecker, R. Kogler, K. Moenig, M. Schott, J. Stelzer
The global electroweak fit at NNLO and prospects for the LHC and ILC
26 pages, 9 figures
null
10.1140/epjc/s10052-014-3046-5
DESY-14-124
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For a long time, global fits of the electroweak sector of the Standard Model (SM) have been used to exploit measurements of electroweak precision observables at lepton colliders (LEP, SLC), together with measurements at hadron colliders (Tevatron, LHC), and accurate theoretical predictions at multi-loop level, to constrain free parameters of the SM, such as the Higgs and top masses. Today, all fundamental SM parameters entering these fits are experimentally determined, including information on the Higgs couplings, and the global fits are used as powerful tools to assess the validity of the theory and to constrain scenarios for new physics. Future measurements at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) promise to improve the experimental precision of key observables used in the fits. This paper presents updated electroweak fit results using newest NNLO theoretical predictions, and prospects for the LHC and ILC. The impact of experimental and theoretical uncertainties is analysed in detail. We compare constraints from the electroweak fit on the Higgs couplings with direct LHC measurements, and examine present and future prospects of these constraints using a model with modified couplings of the Higgs boson to fermions and bosons.
[ { "created": "Mon, 14 Jul 2014 20:00:04 GMT", "version": "v1" } ]
2015-06-22
[ [ "Baak", "M.", "" ], [ "Cuth", "J.", "" ], [ "Haller", "J.", "" ], [ "Hoecker", "A.", "" ], [ "Kogler", "R.", "" ], [ "Moenig", "K.", "" ], [ "Schott", "M.", "" ], [ "Stelzer", "J.", "" ] ]
For a long time, global fits of the electroweak sector of the Standard Model (SM) have been used to exploit measurements of electroweak precision observables at lepton colliders (LEP, SLC), together with measurements at hadron colliders (Tevatron, LHC), and accurate theoretical predictions at multi-loop level, to constrain free parameters of the SM, such as the Higgs and top masses. Today, all fundamental SM parameters entering these fits are experimentally determined, including information on the Higgs couplings, and the global fits are used as powerful tools to assess the validity of the theory and to constrain scenarios for new physics. Future measurements at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) promise to improve the experimental precision of key observables used in the fits. This paper presents updated electroweak fit results using newest NNLO theoretical predictions, and prospects for the LHC and ILC. The impact of experimental and theoretical uncertainties is analysed in detail. We compare constraints from the electroweak fit on the Higgs couplings with direct LHC measurements, and examine present and future prospects of these constraints using a model with modified couplings of the Higgs boson to fermions and bosons.
1504.07617
Jan Hajer
Jan Hajer, Ying-Ying Li, Tao Liu, John F.H. Shiu
Heavy Higgs Bosons at 14 TeV and 100 TeV
published version
null
10.1007/JHEP11(2015)124
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Searching for Higgs bosons beyond the Standard Model (BSM) is one of the most important missions for hadron colliders. As a landmark of BSM physics, the MSSM Higgs sector at the LHC is expected to be tested up to the scale of the decoupling limit of O(1) TeV, except for a wedge region centered around $\tan\beta \sim 3 -10$, which has been known to be difficult to probe. In this article, we present a dedicated study testing the decoupled MSSM Higgs sector, at the LHC and a next-generation $pp$-collider, proposing to search in channels with associated Higgs productions, with the neutral and charged Higgs further decaying into $tt$ and $tb$, respectively. In the case of neutral Higgs we are able to probe for the so far uncovered wedge region via $pp\to bb H/A \to bbtt$. Additionally, we cover the the high $\tan\beta$ range with $pp\to bb H/A \to bb\tau\tau$. The combination of these searches with channels dedicated to the low $\tan\beta$ region, such as $pp\to H/A \to tt$ and $pp\to tt H/A \to tttt$ potentially covers the full $\tan\beta$ range. The search for charged Higgs has a slightly smaller sensitivity for the moderate $\tan\beta$ region, but additionally probes for the higher and lower $\tan\beta$ regions with even greater sensitivity, via $pp\to tb H^\pm \to tbtb$. While the LHC will be able to probe the whole $\tan\beta$ range for Higgs masses of O(1) TeV by combining these channels, we show that a future 100 TeV $pp$-collider has a potential to push the sensitivity reach up to $\sim \mathcal O(10)$ TeV. In order to deal with the novel kinematics of top quarks produced by heavy Higgs decays, the multivariate Boosted Decision Tree (BDT) method is applied in our collider analyses. The BDT-based tagging efficiencies of both hadronic and leptonic top-jets, and their mutual fake rates as well as the faking rates by other jets ($h$, $Z$, $W$, $b$, etc.) are also presented.
[ { "created": "Tue, 28 Apr 2015 19:55:43 GMT", "version": "v1" }, { "created": "Fri, 30 Oct 2015 17:37:27 GMT", "version": "v2" } ]
2016-01-20
[ [ "Hajer", "Jan", "" ], [ "Li", "Ying-Ying", "" ], [ "Liu", "Tao", "" ], [ "Shiu", "John F. H.", "" ] ]
Searching for Higgs bosons beyond the Standard Model (BSM) is one of the most important missions for hadron colliders. As a landmark of BSM physics, the MSSM Higgs sector at the LHC is expected to be tested up to the scale of the decoupling limit of O(1) TeV, except for a wedge region centered around $\tan\beta \sim 3 -10$, which has been known to be difficult to probe. In this article, we present a dedicated study testing the decoupled MSSM Higgs sector, at the LHC and a next-generation $pp$-collider, proposing to search in channels with associated Higgs productions, with the neutral and charged Higgs further decaying into $tt$ and $tb$, respectively. In the case of neutral Higgs we are able to probe for the so far uncovered wedge region via $pp\to bb H/A \to bbtt$. Additionally, we cover the the high $\tan\beta$ range with $pp\to bb H/A \to bb\tau\tau$. The combination of these searches with channels dedicated to the low $\tan\beta$ region, such as $pp\to H/A \to tt$ and $pp\to tt H/A \to tttt$ potentially covers the full $\tan\beta$ range. The search for charged Higgs has a slightly smaller sensitivity for the moderate $\tan\beta$ region, but additionally probes for the higher and lower $\tan\beta$ regions with even greater sensitivity, via $pp\to tb H^\pm \to tbtb$. While the LHC will be able to probe the whole $\tan\beta$ range for Higgs masses of O(1) TeV by combining these channels, we show that a future 100 TeV $pp$-collider has a potential to push the sensitivity reach up to $\sim \mathcal O(10)$ TeV. In order to deal with the novel kinematics of top quarks produced by heavy Higgs decays, the multivariate Boosted Decision Tree (BDT) method is applied in our collider analyses. The BDT-based tagging efficiencies of both hadronic and leptonic top-jets, and their mutual fake rates as well as the faking rates by other jets ($h$, $Z$, $W$, $b$, etc.) are also presented.
hep-ph/9708271
Andrei Shuvaev
Yu. M. Shabelski, A. G. Shuvaev (St.Petersburg Nuclear Physics Institute)
Heavy quark pair correlations in QCD
11 pages, LaTeX, 8 figures
Eur.Phys.J.C6:313-319,1999
10.1007/s100520050342
null
hep-ph
null
The azimutal correlations of heavy quarks produced in the high energy $pp$ ($p\bar{p}$) collisions are calculated in the framework of QCD without the usual assumptions of the parton model. The virtual nature of the interacting gluons as well as their transverse motion and different polarizations are taken into account. We give some predictions for the azimutal correlations of charm and beauty hadrons produced at Tevatron-collider and LHC.
[ { "created": "Thu, 7 Aug 1997 10:03:17 GMT", "version": "v1" } ]
2011-01-25
[ [ "Shabelski", "Yu. M.", "", "St.Petersburg Nuclear Physics\n Institute" ], [ "Shuvaev", "A. G.", "", "St.Petersburg Nuclear Physics\n Institute" ] ]
The azimutal correlations of heavy quarks produced in the high energy $pp$ ($p\bar{p}$) collisions are calculated in the framework of QCD without the usual assumptions of the parton model. The virtual nature of the interacting gluons as well as their transverse motion and different polarizations are taken into account. We give some predictions for the azimutal correlations of charm and beauty hadrons produced at Tevatron-collider and LHC.
1905.02892
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the $P_c(4312)$, $P_c(4440)$, $P_c(4457)$ and related hidden-charm pentaquark states with QCD sum rules
20 pages, 14 figures. arXiv admin note: text overlap with arXiv:1806.10384
Int.J.Mod.Phys.A35(2020)2050003
10.1142/S0217751X20500037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we restudy the ground state mass spectrum of the diquark-diquark-antiquark type $uudc\bar{c}$ pentaquark states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of $13$ in a consistent way. The predicted masses support assigning the $P_c(4312)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$, assigning the $P_c(4440)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$, ${\frac{3}{2}}^-$ or ${\frac{5}{2}}^-$, assigning the $P_c(4457)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$ or ${\frac{3}{2}}^-$.
[ { "created": "Tue, 7 May 2019 09:10:17 GMT", "version": "v1" }, { "created": "Mon, 10 Jun 2019 07:55:52 GMT", "version": "v2" }, { "created": "Tue, 1 Oct 2019 12:15:26 GMT", "version": "v3" }, { "created": "Sat, 21 Dec 2019 13:27:35 GMT", "version": "v4" } ]
2020-02-27
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we restudy the ground state mass spectrum of the diquark-diquark-antiquark type $uudc\bar{c}$ pentaquark states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of $13$ in a consistent way. The predicted masses support assigning the $P_c(4312)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$, assigning the $P_c(4440)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$, ${\frac{3}{2}}^-$ or ${\frac{5}{2}}^-$, assigning the $P_c(4457)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$ or ${\frac{3}{2}}^-$.
2302.07149
Mohammed Boukidi
Hamza Abouabid (1), Abdesslam Arhrib (1), Rachid Benbrik (2), Mohammed Boukidi (2), Jaouad El Falaki (3)((1) Universit\'e Abdelmalek Essaadi, FSTT, Tangier, Morocco, (2) Polydisciplinary Faculty, Laboratory of Fundamental and Applied Physics, Cadi Ayyad University, Sidi Bouzid, Safi, Morocco, (3) LPTHE, Physics Department, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco)
The oblique parameters in the 2HDM with Vector-Like Quarks: Confronting $M_W$ CDF-II Anomaly
37 pages, 13 figures, more discussions added and references updated, version published in JPG
null
10.1088/1361-6471/ad3f34
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The CDF collaboration has released a new measurement of the $W$ boson mass using their complete data set with 8.8 fb$^{-1}$ in $p\bar{p}$ collisions. This result deviates from the Standard Model prediction by around 7$\sigma$. We explain how the two Higgs doublet model (2HDM) with vector-like quarks is affected by the recently discovered W boson mass. In our study, we include both theoretical constraints such as perturbative unitarity and vacuum stability as well as a number of experimental constraints. We also look into how the effective mixing angle, measured by the SLD collaboration in addition to the CDF W-boson mass, is used to determine the $S$ and $T$ parameters. In the alignment limit, we investigate the case where the lighter CP-even neutral Higgs boson of the 2HDM is the one found at the LHC and demonstrate how the parameter space of the 2HDM type II in the presence of vector-like quarks is constrained. It is found that in most cases, there is a cancellation between the 2HDM and vector-like quarks contributions, which enlarges the parameter space of both models.
[ { "created": "Tue, 14 Feb 2023 15:58:49 GMT", "version": "v1" }, { "created": "Wed, 17 Apr 2024 14:29:09 GMT", "version": "v2" } ]
2024-04-18
[ [ "Abouabid", "Hamza", "" ], [ "Arhrib", "Abdesslam", "" ], [ "Benbrik", "Rachid", "" ], [ "Boukidi", "Mohammed", "" ], [ "Falaki", "Jaouad El", "" ] ]
The CDF collaboration has released a new measurement of the $W$ boson mass using their complete data set with 8.8 fb$^{-1}$ in $p\bar{p}$ collisions. This result deviates from the Standard Model prediction by around 7$\sigma$. We explain how the two Higgs doublet model (2HDM) with vector-like quarks is affected by the recently discovered W boson mass. In our study, we include both theoretical constraints such as perturbative unitarity and vacuum stability as well as a number of experimental constraints. We also look into how the effective mixing angle, measured by the SLD collaboration in addition to the CDF W-boson mass, is used to determine the $S$ and $T$ parameters. In the alignment limit, we investigate the case where the lighter CP-even neutral Higgs boson of the 2HDM is the one found at the LHC and demonstrate how the parameter space of the 2HDM type II in the presence of vector-like quarks is constrained. It is found that in most cases, there is a cancellation between the 2HDM and vector-like quarks contributions, which enlarges the parameter space of both models.
1510.06412
Keith Olive
Keith A. Olive
Supersymmetric Dark Matter after Run I at the LHC: From a TeV to a PeV
22 pages, 21 figures, prepared for the Proceedings of the 18th International Conference From the Planck Scale to the Electroweak Scale, 25-29 May 2015, Ioannina, Greece
null
null
FTPI-MINN-15/45, UMN-TH-3508/15
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The absence of low energy supersymmetry in run I data at the LHC has pushed the nominal scale for supersymmetry beyond a TeV. While this is consistent with the discovery of the Higgs boson at \approx 125 GeV, simple models with scalar and gaugino mass universality are being pushed into corners of parameter space. Some possibilities within the constrained minimal supersymmetric extension of the standard model (with four parameters) are discussed along with a one parameter extension in which the Higgs soft masses are non-universal. Also discussed are 2-, 3-, and 4-parameter versions of pure gravity mediated models with a wino, Higgsino, or bino LSP respectively.
[ { "created": "Wed, 21 Oct 2015 20:11:16 GMT", "version": "v1" } ]
2015-10-23
[ [ "Olive", "Keith A.", "" ] ]
The absence of low energy supersymmetry in run I data at the LHC has pushed the nominal scale for supersymmetry beyond a TeV. While this is consistent with the discovery of the Higgs boson at \approx 125 GeV, simple models with scalar and gaugino mass universality are being pushed into corners of parameter space. Some possibilities within the constrained minimal supersymmetric extension of the standard model (with four parameters) are discussed along with a one parameter extension in which the Higgs soft masses are non-universal. Also discussed are 2-, 3-, and 4-parameter versions of pure gravity mediated models with a wino, Higgsino, or bino LSP respectively.
hep-ph/9203201
null
M. Dine, R.G. Leigh, P. Huet, A.D. Linde and D.A. Linde
Comments on the Electroweak Phase Transition
14 pages, 2 figures (not included)
Phys.Lett.B283:319-325,1992
10.1016/0370-2693(92)90026-Z
null
hep-ph
null
We report on an investigation of various problems related to the theory of the electroweak phase transition. This includes a determination of the nature of the phase transition, a discussion of the possible role of higher order radiative corrections and the theory of the formation and evolution of the bubbles of the new phase. We find in particular that no dangerous linear terms appear in the effective potential. However, the strength of the first order phase transition is 2/3 times less than what follows from the one-loop approximation. This rules out baryogenesis in the minimal version of the electroweak theory.
[ { "created": "Mon, 24 Feb 1992 20:07:00 GMT", "version": "v1" } ]
2009-09-29
[ [ "Dine", "M.", "" ], [ "Leigh", "R. G.", "" ], [ "Huet", "P.", "" ], [ "Linde", "A. D.", "" ], [ "Linde", "D. A.", "" ] ]
We report on an investigation of various problems related to the theory of the electroweak phase transition. This includes a determination of the nature of the phase transition, a discussion of the possible role of higher order radiative corrections and the theory of the formation and evolution of the bubbles of the new phase. We find in particular that no dangerous linear terms appear in the effective potential. However, the strength of the first order phase transition is 2/3 times less than what follows from the one-loop approximation. This rules out baryogenesis in the minimal version of the electroweak theory.
2003.09181
Zhan-Wei Liu
Zhan-Wei Liu, Jia-Jun Wu, Derek B. Leinweber, Anthony W. Thomas
Kaonic Hydrogen and Deuterium in Hamiltonian Effective Field Theory
7 pages, 3 figures, published version
Phys. Lett. B 808 (2020) 135652
10.1016/j.physletb.2020.135652
ADP-20-8/T1118
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
The anti-kaon nucleon scattering lengths resulting from a Hamiltonian effective field theory analysis of experimental data and lattice QCD studies are presented. The same Hamiltonian is then used to compute the scattering length for the $K^- d$ system, taking careful account of the effects of recoil on the energy at which the $\bar{K}N$ T-matrices are evaluated. These results are then used to estimate the shift and width of the $1S$ levels of anti-kaonic hydrogen and deuterium. The $K^- p$ result is in excellent agreement with the SIDDHARTA measurement. In the $K^- d$ case the imaginary part of the scattering length and consequently the width of the $1S$ state are considerably larger than found in earlier work. This is a consequence of the effect of recoil on the energy of the $\bar{K}N$ energy, which enhances the role of the $\Lambda(1405)$ resonance.
[ { "created": "Fri, 20 Mar 2020 10:37:47 GMT", "version": "v1" }, { "created": "Wed, 29 Jul 2020 04:33:51 GMT", "version": "v2" } ]
2020-07-30
[ [ "Liu", "Zhan-Wei", "" ], [ "Wu", "Jia-Jun", "" ], [ "Leinweber", "Derek B.", "" ], [ "Thomas", "Anthony W.", "" ] ]
The anti-kaon nucleon scattering lengths resulting from a Hamiltonian effective field theory analysis of experimental data and lattice QCD studies are presented. The same Hamiltonian is then used to compute the scattering length for the $K^- d$ system, taking careful account of the effects of recoil on the energy at which the $\bar{K}N$ T-matrices are evaluated. These results are then used to estimate the shift and width of the $1S$ levels of anti-kaonic hydrogen and deuterium. The $K^- p$ result is in excellent agreement with the SIDDHARTA measurement. In the $K^- d$ case the imaginary part of the scattering length and consequently the width of the $1S$ state are considerably larger than found in earlier work. This is a consequence of the effect of recoil on the energy of the $\bar{K}N$ energy, which enhances the role of the $\Lambda(1405)$ resonance.
2311.17149
Taylor Murphy
Diyar Agin, Benjamin Fuks, Mark D. Goodsell, Taylor Murphy
Monojets reveal overlapping excesses for light compressed higgsinos
7 pages, 2 figures. Updated to resemble Phys. Lett. B Version of Record
Phys. Lett. B 853 (2024) 138597
10.1016/j.physletb.2024.138597
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ATLAS and CMS collaborations have recently presented results of searches for compressed electroweakinos in final states including soft leptons. These searches are sensitive to mass splittings ranging from quite small values of about 5 GeV to O(10) GeV, which are endemic to scenarios with wino-like and higgsino-like lightest supersymmetric particles (LSPs). While all experimental results exhibit apparently compatible mild excesses, these soft-lepton analyses, taken together with disappearing-track searches targeting much smaller splittings, notably leave unconstrained a sizeable region of parameter space with modest splittings of 1-5 GeV. We point out that this gap can be closed, for scenarios with a higgsino-like LSP, by monojet searches. On the other hand, we find at the same time that current monojet searches show excesses in a region partially overlapping that favoured by the soft-lepton analyses. We provide an up-to-date map of these results and show, among others, a best-fit point with an excess greater than $2\sigma$ that is consistent with a higgsino-like LSP mass around 177 GeV. We finally comment on how such a point can be realised in the MSSM.
[ { "created": "Tue, 28 Nov 2023 19:00:01 GMT", "version": "v1" }, { "created": "Fri, 26 Apr 2024 14:34:39 GMT", "version": "v2" } ]
2024-04-29
[ [ "Agin", "Diyar", "" ], [ "Fuks", "Benjamin", "" ], [ "Goodsell", "Mark D.", "" ], [ "Murphy", "Taylor", "" ] ]
The ATLAS and CMS collaborations have recently presented results of searches for compressed electroweakinos in final states including soft leptons. These searches are sensitive to mass splittings ranging from quite small values of about 5 GeV to O(10) GeV, which are endemic to scenarios with wino-like and higgsino-like lightest supersymmetric particles (LSPs). While all experimental results exhibit apparently compatible mild excesses, these soft-lepton analyses, taken together with disappearing-track searches targeting much smaller splittings, notably leave unconstrained a sizeable region of parameter space with modest splittings of 1-5 GeV. We point out that this gap can be closed, for scenarios with a higgsino-like LSP, by monojet searches. On the other hand, we find at the same time that current monojet searches show excesses in a region partially overlapping that favoured by the soft-lepton analyses. We provide an up-to-date map of these results and show, among others, a best-fit point with an excess greater than $2\sigma$ that is consistent with a higgsino-like LSP mass around 177 GeV. We finally comment on how such a point can be realised in the MSSM.
hep-ph/9911335
Gennaro Corcella
Gennaro Corcella (Milano), Michael H. Seymour (RAL)
Simulations of Top Production and Decay at the Linear Collider
6 pages, 3 figures. Talk given at the 2nd ECFA/DESY Study on Physics and Detectors for a Linear Electron-Positron Collider, LNF, Frascati, Italy, 8-10 November 1998
null
null
BICOCCA-FT-99-38, RAL-TR-1999-076
hep-ph
null
We review the present status of simulations of top production and decay in the HERWIG event generator. We show the phenomenological impact of the recently-implemented matrix-element corrections to top decays for e+e- collisions at 360 GeV and discuss possible further improvements for studies of future experiments at the Linear Collider.
[ { "created": "Fri, 12 Nov 1999 18:18:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Corcella", "Gennaro", "", "Milano" ], [ "Seymour", "Michael H.", "", "RAL" ] ]
We review the present status of simulations of top production and decay in the HERWIG event generator. We show the phenomenological impact of the recently-implemented matrix-element corrections to top decays for e+e- collisions at 360 GeV and discuss possible further improvements for studies of future experiments at the Linear Collider.
0903.2329
Omar Benhar
Omar Benhar and Davide Meloni
Impact of nuclear effects on the determination of the nucleon axial mass
4 pages, three figures
Phys.Rev.D80:073003,2009
10.1103/PhysRevD.80.073003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analize the influence of nuclear effects on the determination of the nucleon axial mass from nuclear cross sections. Our work is based on a formalism widely applied to describe electron-nucleus scattering data in the impulse approximation regime. The results of numerical calculations show that correlation effects, not taken into account by the relativistic Fermi gas model, sizably affect the $Q^2$-dependence of the cross section. However, their inclusion does not appear to explain the large values of the axial mass recently reported by the K2K and MiniBooNE collaborations.
[ { "created": "Fri, 13 Mar 2009 08:24:02 GMT", "version": "v1" } ]
2009-10-29
[ [ "Benhar", "Omar", "" ], [ "Meloni", "Davide", "" ] ]
We analize the influence of nuclear effects on the determination of the nucleon axial mass from nuclear cross sections. Our work is based on a formalism widely applied to describe electron-nucleus scattering data in the impulse approximation regime. The results of numerical calculations show that correlation effects, not taken into account by the relativistic Fermi gas model, sizably affect the $Q^2$-dependence of the cross section. However, their inclusion does not appear to explain the large values of the axial mass recently reported by the K2K and MiniBooNE collaborations.
hep-ph/0503048
Grzegorz Wilk
O.V.Utyuzh, G.Wilk and Z.Wlodarczyk
Multiparticle production processes from the Information Theory point of view
Talk given at 4th Budapest Winter School On Heavy Ion Physics (2004) 16 pages, 5 figures; version published in APH (HIP)
Acta Phys.Hung. A25 (2006) 65-81
10.1556/APH.25.2006.1.6
null
hep-ph nucl-th
null
We look at multiparticle production processes from the Information Theory point of view, both in its extensive and nonextensive versions. Examples of both symmetric (like pp or AA) and asymmetric (like pA) collisions are considered showing that some ways of description of experimental data used in the literature are of more general validity than usually anticipated.}
[ { "created": "Fri, 4 Mar 2005 12:29:39 GMT", "version": "v1" }, { "created": "Sat, 5 Mar 2005 14:43:59 GMT", "version": "v2" }, { "created": "Mon, 14 Mar 2005 14:16:15 GMT", "version": "v3" }, { "created": "Sat, 7 May 2005 14:48:13 GMT", "version": "v4" }, { "created": "Wed, 22 Feb 2006 14:02:03 GMT", "version": "v5" } ]
2009-11-11
[ [ "Utyuzh", "O. V.", "" ], [ "Wilk", "G.", "" ], [ "Wlodarczyk", "Z.", "" ] ]
We look at multiparticle production processes from the Information Theory point of view, both in its extensive and nonextensive versions. Examples of both symmetric (like pp or AA) and asymmetric (like pA) collisions are considered showing that some ways of description of experimental data used in the literature are of more general validity than usually anticipated.}
1305.3843
S. Descotes-Genon
V. Bernard (IPN Orsay), S. Descotes-Genon (LPT Orsay), M. Knecht (CPT Marseille)
Isospin breaking in the phases of the Ke4 form factors
48 pages, 7 figures
null
10.1140/epjc/s10052-013-2478-7
CPT-P001-2013, LPT-ORSAY/13-35
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Isospin breaking in the Kl4 form factors induced by the difference between charged and neutral pion masses is studied. Starting from suitably subtracted dispersion representations, the form factors are constructed in an iterative way up to two loops in the low-energy expansion by implementing analyticity, crossing, and unitarity due to two-meson intermediate states. Analytical expressions for the phases of the two-loop form factors of the K\pm -> pi^+ pi^- e^\pm nu_e channel are given, allowing one to connect the difference of form-factor phase shifts measured experimentally (out of the isospin limit) and the difference of S- and P-wave pi-pi phase shifts studied theoretically (in the isospin limit). The isospin-breaking correction consists of the sum of a universal part, involving only pi-pi rescattering, and a process-dependent contribution, involving the form factors in the coupled channels. The dependence on the two S-wave scattering lengths a_0^0 and a_0^2 in the isospin limit is worked out in a general way, in contrast to previous analyses based on one-loop chiral perturbation theory. The latter is used only to assess the subtraction constants involved in the dispersive approach. The two-loop universal and process-dependent contributions are estimated and cancel partially to yield an isospin-breaking correction close to the one-loop case. The recent results on the phases of K^\pm -> pi^+ pi^- e^\pm nu_e form factors obtained by the NA48/2 collaboration at the CERN SPS are reanalysed including this isospin-breaking correction to extract values for the scattering lengths a_0^0 and a_0^2, as well as for low-energy constants and order parameters of two-flavour ChPT.
[ { "created": "Thu, 16 May 2013 15:26:22 GMT", "version": "v1" } ]
2015-06-16
[ [ "Bernard", "V.", "", "IPN Orsay" ], [ "Descotes-Genon", "S.", "", "LPT Orsay" ], [ "Knecht", "M.", "", "CPT\n Marseille" ] ]
Isospin breaking in the Kl4 form factors induced by the difference between charged and neutral pion masses is studied. Starting from suitably subtracted dispersion representations, the form factors are constructed in an iterative way up to two loops in the low-energy expansion by implementing analyticity, crossing, and unitarity due to two-meson intermediate states. Analytical expressions for the phases of the two-loop form factors of the K\pm -> pi^+ pi^- e^\pm nu_e channel are given, allowing one to connect the difference of form-factor phase shifts measured experimentally (out of the isospin limit) and the difference of S- and P-wave pi-pi phase shifts studied theoretically (in the isospin limit). The isospin-breaking correction consists of the sum of a universal part, involving only pi-pi rescattering, and a process-dependent contribution, involving the form factors in the coupled channels. The dependence on the two S-wave scattering lengths a_0^0 and a_0^2 in the isospin limit is worked out in a general way, in contrast to previous analyses based on one-loop chiral perturbation theory. The latter is used only to assess the subtraction constants involved in the dispersive approach. The two-loop universal and process-dependent contributions are estimated and cancel partially to yield an isospin-breaking correction close to the one-loop case. The recent results on the phases of K^\pm -> pi^+ pi^- e^\pm nu_e form factors obtained by the NA48/2 collaboration at the CERN SPS are reanalysed including this isospin-breaking correction to extract values for the scattering lengths a_0^0 and a_0^2, as well as for low-energy constants and order parameters of two-flavour ChPT.
hep-ph/9807407
Jerry Franklin
Jerrold Franklin
Comment on Octet Baryon Magnetic Moments in the Chiral Quark Model with Configuration Mixing
5 pages, Latex file
Phys.Rev. D61 (2000) 098301
10.1103/PhysRevD.61.098301
TUHE9871
hep-ph
null
The importance of exchange currents, and of conserving isotopic spin at both the quark and baryon levels in application of the chiral quark model to any calculation of baryon magnetic moments is emphasized.
[ { "created": "Fri, 17 Jul 1998 19:08:57 GMT", "version": "v1" } ]
2009-10-31
[ [ "Franklin", "Jerrold", "" ] ]
The importance of exchange currents, and of conserving isotopic spin at both the quark and baryon levels in application of the chiral quark model to any calculation of baryon magnetic moments is emphasized.
1607.02142
Javier Fuentes-Mart\'in
Javier Fuentes-Martin, Jorge Portoles, Pedro Ruiz-Femenia
Integrating out heavy particles with functional methods: a simplified framework
24 pages. Uses feynMF package
JHEP 1609 (2016) 156
10.1007/JHEP09(2016)156
IFIC/16-28, TUM-HEP-1047/16
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a systematic procedure to obtain the one-loop low-energy effective Lagrangian resulting from integrating out the heavy fields of a given ultraviolet theory. We show that the matching coefficients are determined entirely by the hard region of the functional determinant involving the heavy fields. This represents an important simplification with respect the conventional matching approach, where the full and effective theory contributions have to be computed separately and a cancellation of the infrared divergent parts has to take place. We illustrate the method with a descriptive toy model and with an extension of the Standard Model with a heavy real scalar triplet. A comparison with other schemes that have been put forward recently is also provided.
[ { "created": "Thu, 7 Jul 2016 20:00:01 GMT", "version": "v1" } ]
2016-10-03
[ [ "Fuentes-Martin", "Javier", "" ], [ "Portoles", "Jorge", "" ], [ "Ruiz-Femenia", "Pedro", "" ] ]
We present a systematic procedure to obtain the one-loop low-energy effective Lagrangian resulting from integrating out the heavy fields of a given ultraviolet theory. We show that the matching coefficients are determined entirely by the hard region of the functional determinant involving the heavy fields. This represents an important simplification with respect the conventional matching approach, where the full and effective theory contributions have to be computed separately and a cancellation of the infrared divergent parts has to take place. We illustrate the method with a descriptive toy model and with an extension of the Standard Model with a heavy real scalar triplet. A comparison with other schemes that have been put forward recently is also provided.
2406.05102
Giacomo Polesello
Roy Aleksan, Emmanuel Perez, Giacomo Polesello, Nicol\`o Valle
Timing-based mass measurement of exotic long-lived particles at the FCC-ee
16 pages, 11 figures, 1 table
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The very high luminosity run foreseen at the $Z$-pole for the FCC-ee will allow the detection in $Z$ decays of new particles with very low couplings to the Standard Model. These particles will have measurable flight paths before they decay. If the timing and the position of the decay vertex can be measured with high precision, the mass of such particles can be measured by exploiting the constrained kinematics of an $e^+e^-$ collider. The mass resolution achievable with this technique is studied through a detailed analysis in the framework of a parametrised simulation of the performance of the IDEA detector. The adopted benchmark model is the production of Heavy Neutral Leptons, which is one of the key channels for new physics discovery at the FCC-ee.
[ { "created": "Mon, 3 Jun 2024 12:35:33 GMT", "version": "v1" } ]
2024-06-10
[ [ "Aleksan", "Roy", "" ], [ "Perez", "Emmanuel", "" ], [ "Polesello", "Giacomo", "" ], [ "Valle", "Nicolò", "" ] ]
The very high luminosity run foreseen at the $Z$-pole for the FCC-ee will allow the detection in $Z$ decays of new particles with very low couplings to the Standard Model. These particles will have measurable flight paths before they decay. If the timing and the position of the decay vertex can be measured with high precision, the mass of such particles can be measured by exploiting the constrained kinematics of an $e^+e^-$ collider. The mass resolution achievable with this technique is studied through a detailed analysis in the framework of a parametrised simulation of the performance of the IDEA detector. The adopted benchmark model is the production of Heavy Neutral Leptons, which is one of the key channels for new physics discovery at the FCC-ee.
1102.0392
Marco Ciuchini
Marco Ciuchini, Maurizio Pierini and Luca Silvestrini
Theoretical uncertainty in sin 2beta: An update
8 pages, 2 figures, 3 tables, Proceedings of CKM2010, the 6th International Workshop on the CKM Unitarity Triangle, University of Warwick, UK, 6-10 September 2010
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The source of theoretical uncertainty in the extraction of sin 2beta from the measurement of the golden channel Bd -> J/psi K0 is briefly reviewed. An updated estimate of this uncertainty based on SU(3) flavour symmetry and the measurement of the decay Bd -> J/psi pi0 is also presented.
[ { "created": "Wed, 2 Feb 2011 09:53:57 GMT", "version": "v1" } ]
2011-02-03
[ [ "Ciuchini", "Marco", "" ], [ "Pierini", "Maurizio", "" ], [ "Silvestrini", "Luca", "" ] ]
The source of theoretical uncertainty in the extraction of sin 2beta from the measurement of the golden channel Bd -> J/psi K0 is briefly reviewed. An updated estimate of this uncertainty based on SU(3) flavour symmetry and the measurement of the decay Bd -> J/psi pi0 is also presented.
hep-ph/0506285
Matteo Beccaria
Matteo Beccaria
Sudakov Expansions and Top Quark Physics at LHC
4 pages, PostScript file
null
10.1063/1.2125634
XVII Incontri di Fisica delle Alte Energie - IFAE 2005 Catania, 30/3 - 2/4 2005
hep-ph
null
We review some peculiar features of Sudakov expansions in the calculation of electroweak radiative corrections in the MSSM at high energy. We give specific examples and consider in particular the process b g -> t W of single top quark production relevant for the top quark physics programme at LHC.
[ { "created": "Tue, 28 Jun 2005 08:30:13 GMT", "version": "v1" } ]
2015-06-25
[ [ "Beccaria", "Matteo", "" ] ]
We review some peculiar features of Sudakov expansions in the calculation of electroweak radiative corrections in the MSSM at high energy. We give specific examples and consider in particular the process b g -> t W of single top quark production relevant for the top quark physics programme at LHC.
hep-ph/9408247
Andrei Linde
V.V.Kopenkin, A.K.Managadze, I.V.Rakobolskaya, T.M.Roganova
Alignment in Gamma-Hadron Families of Cosmic Rays
15 pages, 2 tables, 6 figures (not included), Stanford University preprint SU-ITP-94-25
Phys. Rev. D 52, 2766 (1995)
10.1103/PhysRevD.52.2766
null
hep-ph hep-th nucl-th
null
Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, $E_0 > 10^{16}$ eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.
[ { "created": "Sat, 6 Aug 1994 00:22:54 GMT", "version": "v1" } ]
2016-08-24
[ [ "Kopenkin", "V. V.", "" ], [ "Managadze", "A. K.", "" ], [ "Rakobolskaya", "I. V.", "" ], [ "Roganova", "T. M.", "" ] ]
Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, $E_0 > 10^{16}$ eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.
1705.05388
Farinaldo Queiroz
Miguel D. Campos, D. Cogollo, Manfred Lindner, T. Melo, Farinaldo S. Queiroz, Werner Rodejohann
Neutrino Masses and Absence of Flavor Changing Interactions in the 2HDM from Gauge Principles
54 pages, 10 figures
null
10.1007/JHEP08(2017)092
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose several Two Higgs Doublet Models with the addition of an Abelian gauge group which free the usual framework from flavor changing neutral interactions and explain neutrino masses through the seesaw mechanism. We discuss the kinetic and mass-mixing gripping phenomenology which encompass several constraints coming from atomic parity violation, the muon anomalous magnetic moment, rare meson decays, Higgs physics, LEP precision data, neutrino-electron scattering, low energy accelerators and LHC probes.
[ { "created": "Mon, 15 May 2017 18:00:07 GMT", "version": "v1" } ]
2017-09-13
[ [ "Campos", "Miguel D.", "" ], [ "Cogollo", "D.", "" ], [ "Lindner", "Manfred", "" ], [ "Melo", "T.", "" ], [ "Queiroz", "Farinaldo S.", "" ], [ "Rodejohann", "Werner", "" ] ]
We propose several Two Higgs Doublet Models with the addition of an Abelian gauge group which free the usual framework from flavor changing neutral interactions and explain neutrino masses through the seesaw mechanism. We discuss the kinetic and mass-mixing gripping phenomenology which encompass several constraints coming from atomic parity violation, the muon anomalous magnetic moment, rare meson decays, Higgs physics, LEP precision data, neutrino-electron scattering, low energy accelerators and LHC probes.
1603.05932
Oscar Moreno
O. Moreno, T. W. Donnelly
Elastic vector and axial scattering of weakly interacting particles off nuclei
11 pages, 14 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the elastic scattering of particles interacting with nuclei through vector and axial currents with overall couplings of the order of the Standard Model weak interaction, or smaller; the dominant contribution to the elastic cross section is identified as the coherent component and is therefore spin-independent. Differential and integrated cross sections are obtained for a wide range of incident particle masses and velocities and for nuclear targets with different masses; vector, axial and overall couplings of the incident particle and of the hadronic target to the massive exchanged boson are also kept general. This study naturally encompasses several kinds of possible dark matter components, including active and sterile neutrinos or neutralinos, and addresses the prospects for their direct detection through elastic scattering off nuclei.
[ { "created": "Thu, 17 Mar 2016 16:25:26 GMT", "version": "v1" } ]
2016-03-21
[ [ "Moreno", "O.", "" ], [ "Donnelly", "T. W.", "" ] ]
We analyze the elastic scattering of particles interacting with nuclei through vector and axial currents with overall couplings of the order of the Standard Model weak interaction, or smaller; the dominant contribution to the elastic cross section is identified as the coherent component and is therefore spin-independent. Differential and integrated cross sections are obtained for a wide range of incident particle masses and velocities and for nuclear targets with different masses; vector, axial and overall couplings of the incident particle and of the hadronic target to the massive exchanged boson are also kept general. This study naturally encompasses several kinds of possible dark matter components, including active and sterile neutrinos or neutralinos, and addresses the prospects for their direct detection through elastic scattering off nuclei.
hep-ph/9801342
Shinohara Tadatomi
I.S.Sogami, K.Nishida, H.Tanaka, T.Shinohara (Kyoto Sangyo University)
Approximate Sum Rules of CKM Matrix Elements from Quasi-Democratic Mass Matrices
Latex, 15 pages, no figures
Prog.Theor.Phys.99:281-292,1998
10.1143/PTP.99.281
null
hep-ph
null
To extract sum rules of CKM matrix elements, eigenvalue problems for quasi-democratic mass matrices are solved in the first order perturbation approximation with respect to small deviations from the democratic limit. Mass spectra of up and down quark sectors and the CKM matrix are shown to have clear and distinctive hierarchical structures. Numerical analysis shows that the absolute values of calculated CKM matrix elements fit the experimental data quite well. The order of the magnitude of the Jarlskog parameter is estimated by the relation $|J| \approx \sqrt{2}(m_c/m_t + m_s/m_b)|V_{us}|^2|V_{cb}|/4$.
[ { "created": "Mon, 19 Jan 1998 12:14:23 GMT", "version": "v1" } ]
2014-11-17
[ [ "Sogami", "I. S.", "", "Kyoto Sangyo University" ], [ "Nishida", "K.", "", "Kyoto Sangyo University" ], [ "Tanaka", "H.", "", "Kyoto Sangyo University" ], [ "Shinohara", "T.", "", "Kyoto Sangyo University" ] ]
To extract sum rules of CKM matrix elements, eigenvalue problems for quasi-democratic mass matrices are solved in the first order perturbation approximation with respect to small deviations from the democratic limit. Mass spectra of up and down quark sectors and the CKM matrix are shown to have clear and distinctive hierarchical structures. Numerical analysis shows that the absolute values of calculated CKM matrix elements fit the experimental data quite well. The order of the magnitude of the Jarlskog parameter is estimated by the relation $|J| \approx \sqrt{2}(m_c/m_t + m_s/m_b)|V_{us}|^2|V_{cb}|/4$.
hep-ph/0608108
Jaroslaw Nowak
Jaroslaw A. Nowak and Jan T. Sobczyk
Hadron production in Wroclaw neutrino event generator
Presented at 20th Max Born Symposium: Nuclear Effects in Neutrino Interactions, Wroclaw, Poland, 7-10 Dec 2005
Acta Phys.Polon. B37 (2006) 2371-2378
null
null
hep-ph hep-ex
null
Results from the Wroclaw Monte Carlo neutrino generator of events are reported. Predictions for charged hadron multiplicities, neutral pion and strange particle production are presented and compared with available data.
[ { "created": "Thu, 10 Aug 2006 11:07:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nowak", "Jaroslaw A.", "" ], [ "Sobczyk", "Jan T.", "" ] ]
Results from the Wroclaw Monte Carlo neutrino generator of events are reported. Predictions for charged hadron multiplicities, neutral pion and strange particle production are presented and compared with available data.
hep-ph/9607278
Copenhagen Bennett
D.L. Bennett, H.B. Nielsen (The Niels Bohr Institute)
Gauge Couplings calculated from Multiple Point Criticality yield $\alpha^{-1}=136._8\pm 9$: At Last the Elusive Case of $U(1)$
4 figures, 85 pages, accepted for publication in Intl. J. Mod. Phys. A, this is a second replacement that should correct the lack of references in the original version
Int.J.Mod.Phys. A14 (1999) 3313-3385
10.1142/S0217751X9900155X
NBI-HE-96-29
hep-ph
null
We calculate the $U(1)$ continuum gauge coupling using the values of action parameters at the multiple point in the phase diagram of a lattice gauge theory. The multiple point is where a maximum number of phases convene. We obtain for the running inverse finestructure constant the values $\alpha_1^{-1}=56\pm 5$ and $\alpha_1^{-1}=99\pm 5$ at respectively the Planck scale and the $M_Z$ scale. The gauge group underlying the phase diagram in which we seek multiple point values of action parameters is what we call the Anti Grand Unified Theory (AGUT) gauge group $SMG^3$ which is the Cartesian product of 3 standard model groups (SMGs). There is one SMG factor for each of the $N_{gen}=3$ generations of quarks and leptons. In our model, this gauge group $SMG^3$ is the predecessor to the usual standard model group. The latter arises as the diagonal subgroup surviving the Planck scale breakdown of $SMG^3. This breakdown leads to a weakening of the $U(1)$ coupling by a $N_{gen}$-related factor. The most important correction obtained from using multiple point parameter values (in a multi-parameter phase diagram instead of the single critical parameter value obtained say in the 1-dimensional phase diagram of a Wilson action) comes from including the influence of having phases confined solely w.r.t. discrete subgroups. In particular, what matters is that the degree of first-orderness is taken into account in making the transition from these latter phases at the multiple point to the totally Coulomb-like phase. Combined with the results of earlier work on the non-Abelian gauge couplings, the results presented here lead to our prediction of $\alpha^{-1}=136._8\pm 9$ as the value for the fine-structure constant at low energies.
[ { "created": "Wed, 10 Jul 1996 13:07:04 GMT", "version": "v1" }, { "created": "Sun, 14 Jul 1996 18:01:00 GMT", "version": "v2" } ]
2009-10-28
[ [ "Bennett", "D. L.", "", "The Niels Bohr Institute" ], [ "Nielsen", "H. B.", "", "The Niels Bohr Institute" ] ]
We calculate the $U(1)$ continuum gauge coupling using the values of action parameters at the multiple point in the phase diagram of a lattice gauge theory. The multiple point is where a maximum number of phases convene. We obtain for the running inverse finestructure constant the values $\alpha_1^{-1}=56\pm 5$ and $\alpha_1^{-1}=99\pm 5$ at respectively the Planck scale and the $M_Z$ scale. The gauge group underlying the phase diagram in which we seek multiple point values of action parameters is what we call the Anti Grand Unified Theory (AGUT) gauge group $SMG^3$ which is the Cartesian product of 3 standard model groups (SMGs). There is one SMG factor for each of the $N_{gen}=3$ generations of quarks and leptons. In our model, this gauge group $SMG^3$ is the predecessor to the usual standard model group. The latter arises as the diagonal subgroup surviving the Planck scale breakdown of $SMG^3. This breakdown leads to a weakening of the $U(1)$ coupling by a $N_{gen}$-related factor. The most important correction obtained from using multiple point parameter values (in a multi-parameter phase diagram instead of the single critical parameter value obtained say in the 1-dimensional phase diagram of a Wilson action) comes from including the influence of having phases confined solely w.r.t. discrete subgroups. In particular, what matters is that the degree of first-orderness is taken into account in making the transition from these latter phases at the multiple point to the totally Coulomb-like phase. Combined with the results of earlier work on the non-Abelian gauge couplings, the results presented here lead to our prediction of $\alpha^{-1}=136._8\pm 9$ as the value for the fine-structure constant at low energies.
2406.00756
Daeho Park
Daeho Park, Su Houng Lee
An AI-Inspired Numerical Method in the Quark Model: Application to Finding the Wave Functions for Heavy Tetraquark States
7 pages, 5 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The current ongoing advancements in AI have shed light on the landscape of numerical analysis in science. Inspired by the path of achievement of AI, we have developed a method to construct accurate ground state wave functions of multiquark configurations within a quark model. We successfully tested our method through comparisons with meson-type two-body systems with analytic and numerical solutions. We then applied our method to find the ground-state solutions of $T_{cc}$($ud\bar{c}\bar{c}$) and $T_{bb}$($ud\bar{b}\bar{b}$) states. Our findings indicate that our approach outperforms existing methods, achieving greater accuracy in reproducing highly intricate configurations. Within the model parameters, we find that the $T_{cc}$ is a compact multiquark configuration.
[ { "created": "Sun, 2 Jun 2024 14:18:28 GMT", "version": "v1" } ]
2024-06-04
[ [ "Park", "Daeho", "" ], [ "Lee", "Su Houng", "" ] ]
The current ongoing advancements in AI have shed light on the landscape of numerical analysis in science. Inspired by the path of achievement of AI, we have developed a method to construct accurate ground state wave functions of multiquark configurations within a quark model. We successfully tested our method through comparisons with meson-type two-body systems with analytic and numerical solutions. We then applied our method to find the ground-state solutions of $T_{cc}$($ud\bar{c}\bar{c}$) and $T_{bb}$($ud\bar{b}\bar{b}$) states. Our findings indicate that our approach outperforms existing methods, achieving greater accuracy in reproducing highly intricate configurations. Within the model parameters, we find that the $T_{cc}$ is a compact multiquark configuration.
hep-ph/0011002
Serguei Alekhine
Alekhin Sergey (IHEP, Protvino)
Global fit to the charged leptons DIS data: \boldmath{$\alpha_{\rm s}$,} parton distributions, and high twists
34 pages, REVTeX, 14 figures (EPS)
Phys.Rev. D63 (2001) 094022
null
null
hep-ph
null
We perform the NLO QCD analysis of the world data on inclusive deep inelastic scattering cross sections of charged leptons off the proton and the deuterium targets. The parton distributions, the value of strong coupling constant $\alpha_{\rm s}$, and the twist 4 contributions to the structure functions $F_2$ and $F_{\rm L}$ are extracted with the complete account for the correlations of data points due to the systematic errors. Sensitivity of the $\alpha_{\rm s}$ value and the high twist contribution to the procedures of accounting for the systematic errors is studied. The impact of theoretical uncertainties on the value of $\alpha_{\rm s}$ and on the parton distributions is analysed. The obtained value of strong coupling constant with the account of these uncertainties is $\alpha_{\rm s}(M_{\rm Z})=0.1165\pm0.0017({\rm stat+syst}) \pm^{0.0026}_{0.0034}({\rm theor})$. The uncertainties of parton-parton luminosities for the FNAL and LHC colliders are estimated.
[ { "created": "Wed, 1 Nov 2000 01:07:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sergey", "Alekhin", "", "IHEP, Protvino" ] ]
We perform the NLO QCD analysis of the world data on inclusive deep inelastic scattering cross sections of charged leptons off the proton and the deuterium targets. The parton distributions, the value of strong coupling constant $\alpha_{\rm s}$, and the twist 4 contributions to the structure functions $F_2$ and $F_{\rm L}$ are extracted with the complete account for the correlations of data points due to the systematic errors. Sensitivity of the $\alpha_{\rm s}$ value and the high twist contribution to the procedures of accounting for the systematic errors is studied. The impact of theoretical uncertainties on the value of $\alpha_{\rm s}$ and on the parton distributions is analysed. The obtained value of strong coupling constant with the account of these uncertainties is $\alpha_{\rm s}(M_{\rm Z})=0.1165\pm0.0017({\rm stat+syst}) \pm^{0.0026}_{0.0034}({\rm theor})$. The uncertainties of parton-parton luminosities for the FNAL and LHC colliders are estimated.
hep-ph/0703261
Juan Antonio Aguilar-Saavedra
F. del Aguila, J. A. Aguilar-Saavedra, R. Pittau
Heavy neutrino signals at large hadron colliders
Latex 36 pages, 49 PS figures. Major extension incorporating analysis for e+- e+-, e+- mu+- and e+- mu-+ final states. Final version to appear in JHEP
JHEP0710:047,2007
10.1088/1126-6708/2007/10/047
null
hep-ph
null
We study the LHC discovery potential for heavy Majorana neutrino singlets in the process pp -> W+ -> l+ N -> l+ l+ jj (l=e,mu) plus its charge conjugate. With a fast detector simulation we show that backgrounds involving two like-sign charged leptons are not negligible and, moreover, they cannot be eliminated with simple sequential kinematical cuts. Using a likelihood analysis it is shown that, for heavy neutrinos coupling only to the muon, LHC has 5 sigma sensitivity for masses up to 200 GeV in the final state mu+- mu+- jj. This reduction in sensitivity, compared to previous parton-level estimates, is driven by the ~ 10^2-10^3 times larger background. Limits are also provided for e+- e+- jj and e+- mu+- jj final states, as well as for Tevatron. For heavy Dirac neutrinos the prospects are worse because backgrounds involving two opposite charge leptons are much larger. For this case, we study the observability of the lepton flavour violating signal e+- mu-+ jj. As a by-product of our analysis, heavy neutrino production has been implemented within the ALPGEN framework.
[ { "created": "Fri, 23 Mar 2007 19:58:43 GMT", "version": "v1" }, { "created": "Sat, 14 Apr 2007 11:07:58 GMT", "version": "v2" }, { "created": "Thu, 23 Aug 2007 17:55:09 GMT", "version": "v3" }, { "created": "Wed, 3 Oct 2007 22:13:43 GMT", "version": "v4" } ]
2008-11-26
[ [ "del Aguila", "F.", "" ], [ "Aguilar-Saavedra", "J. A.", "" ], [ "Pittau", "R.", "" ] ]
We study the LHC discovery potential for heavy Majorana neutrino singlets in the process pp -> W+ -> l+ N -> l+ l+ jj (l=e,mu) plus its charge conjugate. With a fast detector simulation we show that backgrounds involving two like-sign charged leptons are not negligible and, moreover, they cannot be eliminated with simple sequential kinematical cuts. Using a likelihood analysis it is shown that, for heavy neutrinos coupling only to the muon, LHC has 5 sigma sensitivity for masses up to 200 GeV in the final state mu+- mu+- jj. This reduction in sensitivity, compared to previous parton-level estimates, is driven by the ~ 10^2-10^3 times larger background. Limits are also provided for e+- e+- jj and e+- mu+- jj final states, as well as for Tevatron. For heavy Dirac neutrinos the prospects are worse because backgrounds involving two opposite charge leptons are much larger. For this case, we study the observability of the lepton flavour violating signal e+- mu-+ jj. As a by-product of our analysis, heavy neutrino production has been implemented within the ALPGEN framework.
0807.4922
Takayuki Kubo
Masaki Asano, Takayuki Kubo, Shigeki Matsumoto and Masato Senami
Light Higgs boson scenario in the SUSY seesaw model
17 pages, 5 figures
Phys. Rev. D 80, 095017 (2009)
10.1103/PhysRevD.80.095017
UT-HET 012, KEK-TH-1264
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is demonstrated that the light Higgs boson scenario, which the lightest Higgs mass is less than the LEP bound, mh > 114.4 GeV, is consistent with the SUSY seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass is investigated in terms of lepton flavor violating charged lepton decays. We also discuss the effect of the modification of renormalization group equations by the right-handed neutrinos on the b to s gamma process and the relic abundance of dark matter in the light Higgs boson scenario.
[ { "created": "Wed, 30 Jul 2008 19:06:05 GMT", "version": "v1" } ]
2013-05-29
[ [ "Asano", "Masaki", "" ], [ "Kubo", "Takayuki", "" ], [ "Matsumoto", "Shigeki", "" ], [ "Senami", "Masato", "" ] ]
It is demonstrated that the light Higgs boson scenario, which the lightest Higgs mass is less than the LEP bound, mh > 114.4 GeV, is consistent with the SUSY seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass is investigated in terms of lepton flavor violating charged lepton decays. We also discuss the effect of the modification of renormalization group equations by the right-handed neutrinos on the b to s gamma process and the relic abundance of dark matter in the light Higgs boson scenario.
1611.08786
Ai-Jun Ma
Ai-Jun Ma, Ya Li, Wen-Fei Wang and Zhen-Jun Xiao
The quasi-two-body decays $B_{(s)} \to (D_{(s)},\bar{D}_{(s)}) \rho \to (D_{(s)}, \bar{D}_{(s)})\pi \pi$ in the perturbative QCD factorization approach
17 pages, 3 figures and 2 tables. matching the published version
Nucl.Phys. B923 (2017) 54-72
10.1016/j.nuclphysb.2017.07.014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we studied the $B_{(s)} \to (D_{(s)},\bar{D}_{(s)}) \rho \to (D_{(s)}, \bar{D}_{(s)})\pi \pi$ decays by employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach. We use the two-pion distribution amplitudes $\Phi_{\pi\pi}$, which contains both resonant and nonresonant contributions from the pion pair, to describe the final state interactions (FSIs) between the pions in the resonant region. We found that (a) for all considered decays, the PQCD predictions for their branching ratios based on the quasi-two-body and the two-body framework agree well with each other due to ${\cal B}(\rho \to \pi\pi) \approx 100\%$; For $B^+\to \bar{D^0}\rho^+\to \bar{D^0}\pi^+ \pi^0$ and other four considered decay modes, the PQCD predictions do agree well with the measured values within errors; (b) the great difference between the PQCD predictions for ${\cal B}(B\to \bar{D} \rho \to \bar{D} \pi\pi)$ and ${\cal B}(B\to D \rho \to D \pi\pi)$ can be understood by the strong CKM suppression factor $ R_{\rm CKM} \approx 3 \times 10^{-4}$; (c) for the $B_s\to D \rho \to D \pi\pi$ and $B_s\to \bar{D} \rho \to \bar{D} \pi\pi$ decays, however, the PQCD predictions of $R_{\rm s1}\approx 0.13$ and $R_{\rm s2}\approx 0.14$ do agree very well with the moderate CKM suppression factor $R^s_{\rm CKM}\approx 0.14$; and (d) the PQCD predictions for the ratios $R_{D\rho}$ and the strong phase difference $\cos\delta_{D\rho}$ of the three $B \to \bar{D} \rho$ decay modes agree well with the LHCb measurements within one standard deviation.
[ { "created": "Sun, 27 Nov 2016 04:43:24 GMT", "version": "v1" }, { "created": "Tue, 14 Feb 2017 07:17:24 GMT", "version": "v2" }, { "created": "Wed, 14 Jun 2017 12:22:59 GMT", "version": "v3" }, { "created": "Fri, 15 Sep 2017 03:08:14 GMT", "version": "v4" } ]
2017-09-18
[ [ "Ma", "Ai-Jun", "" ], [ "Li", "Ya", "" ], [ "Wang", "Wen-Fei", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper, we studied the $B_{(s)} \to (D_{(s)},\bar{D}_{(s)}) \rho \to (D_{(s)}, \bar{D}_{(s)})\pi \pi$ decays by employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach. We use the two-pion distribution amplitudes $\Phi_{\pi\pi}$, which contains both resonant and nonresonant contributions from the pion pair, to describe the final state interactions (FSIs) between the pions in the resonant region. We found that (a) for all considered decays, the PQCD predictions for their branching ratios based on the quasi-two-body and the two-body framework agree well with each other due to ${\cal B}(\rho \to \pi\pi) \approx 100\%$; For $B^+\to \bar{D^0}\rho^+\to \bar{D^0}\pi^+ \pi^0$ and other four considered decay modes, the PQCD predictions do agree well with the measured values within errors; (b) the great difference between the PQCD predictions for ${\cal B}(B\to \bar{D} \rho \to \bar{D} \pi\pi)$ and ${\cal B}(B\to D \rho \to D \pi\pi)$ can be understood by the strong CKM suppression factor $ R_{\rm CKM} \approx 3 \times 10^{-4}$; (c) for the $B_s\to D \rho \to D \pi\pi$ and $B_s\to \bar{D} \rho \to \bar{D} \pi\pi$ decays, however, the PQCD predictions of $R_{\rm s1}\approx 0.13$ and $R_{\rm s2}\approx 0.14$ do agree very well with the moderate CKM suppression factor $R^s_{\rm CKM}\approx 0.14$; and (d) the PQCD predictions for the ratios $R_{D\rho}$ and the strong phase difference $\cos\delta_{D\rho}$ of the three $B \to \bar{D} \rho$ decay modes agree well with the LHCb measurements within one standard deviation.
2006.14388
Luciano Maiani prof
C. Becchi, A. Giachino, L. Maiani, E. Santopinto
A study of $c c\bar{c}\bar{c}$ tetraquark decays in 4 muons and in $D^{(*)} \bar{D}^{(*)}$ at LHC
comments added, new figure, new references
null
10.1016/j.physletb.2020.135952
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a quantitative analysis of the decays of $cc\bar c\bar c$ tetraquarks with $J^{PC}=0^{++}, 2^{++}$ into 4 muons and into hidden- and open-charm mesons and estimate, for the first time, the fully charmed tetraquark decay width. The calculated cross section upper limit is $\sim 40$ fb for the 4 muons channel, and $\sim 28$ nb for the $D^{(*)} \bar D^{(*)} \to e\mu$ channel. On the basis of our results, with the present sensitivity LHCb should detect both signals, for $0^{++}$ and $2^{++}$ fully-charmed tetraquarks.
[ { "created": "Thu, 25 Jun 2020 13:23:14 GMT", "version": "v1" }, { "created": "Sun, 4 Oct 2020 05:53:57 GMT", "version": "v2" } ]
2020-12-30
[ [ "Becchi", "C.", "" ], [ "Giachino", "A.", "" ], [ "Maiani", "L.", "" ], [ "Santopinto", "E.", "" ] ]
We perform a quantitative analysis of the decays of $cc\bar c\bar c$ tetraquarks with $J^{PC}=0^{++}, 2^{++}$ into 4 muons and into hidden- and open-charm mesons and estimate, for the first time, the fully charmed tetraquark decay width. The calculated cross section upper limit is $\sim 40$ fb for the 4 muons channel, and $\sim 28$ nb for the $D^{(*)} \bar D^{(*)} \to e\mu$ channel. On the basis of our results, with the present sensitivity LHCb should detect both signals, for $0^{++}$ and $2^{++}$ fully-charmed tetraquarks.
1107.0559
Artem Lipatov
A.V. Lipatov, N.P. Zotov
Phenomenology of kt-factorization for inclusive top quark pair production at hadron colliders
8 pages, 2 figures
Phys. Lett. B 704, 189 (2011)
10.1016/j.physletb.2011.08.072
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the inclusive top quark pair production in proton-proton and proton-antiproton collisions at high energies in the framework of kt-factorization QCD approach. Our study is based on the off-shell partonic subprocesses g*g* -> QQ and q*q* -> QQ, where the transverse momentum of both incoming quarks and gluons are taken into account. The unintegrated parton densities in a proton are determined by the Kimber-Martin-Ryskin prescription as well as the CCFM evolution equation. The conservative error analisys is performed and comparison with the results of traditional NLO pQCD calculations is done. Our predictions agree well with the recent experimental data taken by the D0, CDF, CMS and ATLAS collaborations at the Tevatron and LHC energies.
[ { "created": "Mon, 4 Jul 2011 08:32:22 GMT", "version": "v1" } ]
2015-05-28
[ [ "Lipatov", "A. V.", "" ], [ "Zotov", "N. P.", "" ] ]
We investigate the inclusive top quark pair production in proton-proton and proton-antiproton collisions at high energies in the framework of kt-factorization QCD approach. Our study is based on the off-shell partonic subprocesses g*g* -> QQ and q*q* -> QQ, where the transverse momentum of both incoming quarks and gluons are taken into account. The unintegrated parton densities in a proton are determined by the Kimber-Martin-Ryskin prescription as well as the CCFM evolution equation. The conservative error analisys is performed and comparison with the results of traditional NLO pQCD calculations is done. Our predictions agree well with the recent experimental data taken by the D0, CDF, CMS and ATLAS collaborations at the Tevatron and LHC energies.
1211.7267
Leonid Glozman
L. Ya. Glozman
Confinement, chiral symmetry breaking and the mass generation of hadrons
Invited talk at Light Cone 2012, 8-13 July, 2012, Cracow, Poland
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A key question to QCD is what mechanism generates the hadron mass in the light quark sector, where both confinement and chiral symmetry breaking are in the game. Are confinement and chiral symmetry breaking in the vacuum uniquely interconnected? Can hadrons survive chiral symmetry restoration? If yes, what happens with their mass and what symmetries beyond the chiral symmetry are there? We review our recent insights. In particular, in a dynamical lattice simulation we artificially restore chiral symmetry by removing the low-lying Dirac modes of the valence quark propagators, which is a well defined procedure and keep gluodynamics intact. Hadrons survive this artificial chiral restoration and their mass is surprisingly large. All hadrons fall into chiral multiplets and some of them are degenerate, i.e. the spectrum reveals some higher symmetry, that includes the chiral symmetry as a subgroup. The U(1)_A symmetry does not get restored after removal of the chiral modes from the valence quarks.
[ { "created": "Fri, 30 Nov 2012 14:38:39 GMT", "version": "v1" } ]
2012-12-03
[ [ "Glozman", "L. Ya.", "" ] ]
A key question to QCD is what mechanism generates the hadron mass in the light quark sector, where both confinement and chiral symmetry breaking are in the game. Are confinement and chiral symmetry breaking in the vacuum uniquely interconnected? Can hadrons survive chiral symmetry restoration? If yes, what happens with their mass and what symmetries beyond the chiral symmetry are there? We review our recent insights. In particular, in a dynamical lattice simulation we artificially restore chiral symmetry by removing the low-lying Dirac modes of the valence quark propagators, which is a well defined procedure and keep gluodynamics intact. Hadrons survive this artificial chiral restoration and their mass is surprisingly large. All hadrons fall into chiral multiplets and some of them are degenerate, i.e. the spectrum reveals some higher symmetry, that includes the chiral symmetry as a subgroup. The U(1)_A symmetry does not get restored after removal of the chiral modes from the valence quarks.
1712.05246
Kre\v{s}imir Kumeri\v{c}ki
Kresimir Kumericki, Timon Mede, Ivica Picek
Renormalizable SU(5) Completions of a Zee-type Neutrino Mass Model
LaTeX, 31 pages
Phys. Rev. D 97, 055012 (2018)
10.1103/PhysRevD.97.055012
ZTF-EP-17-07
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the potential of a selected model of radiative neutrino masses to be implemented in a renormalizable SU(5) unification framework. The Zee-type model under consideration uncovers the SU(5) representations in which the new fields are embedded and which may contain also other light states leading to the unification of gauge couplings. We perform an exhaustive search which reveals specific patterns of new states and demonstrate that such patterns are consistent with a general choice of relevant scalar potential. It turns out that all of the specific scenarios which lead to successful unification include the colored scalars testable at the LHC.
[ { "created": "Thu, 14 Dec 2017 14:26:18 GMT", "version": "v1" } ]
2018-03-14
[ [ "Kumericki", "Kresimir", "" ], [ "Mede", "Timon", "" ], [ "Picek", "Ivica", "" ] ]
We explore the potential of a selected model of radiative neutrino masses to be implemented in a renormalizable SU(5) unification framework. The Zee-type model under consideration uncovers the SU(5) representations in which the new fields are embedded and which may contain also other light states leading to the unification of gauge couplings. We perform an exhaustive search which reveals specific patterns of new states and demonstrate that such patterns are consistent with a general choice of relevant scalar potential. It turns out that all of the specific scenarios which lead to successful unification include the colored scalars testable at the LHC.
1411.6975
Olga Solovtsova
A.V. Sidorov, O.P. Solovtsova
Polarized nonsinglet {Delta q}_3 and nonsinglet fragmentation function D^{pi+}_{u_v} in the analytic approach to QCD
7 pages, 8 figures, talk given at the XXII International Baldin Seminar on High Energy Physics Problems, September 15-20, 2014, JINR, Dubna, Russia. Some minor typos are corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the application of an analytic approach called the analytic perturbation theory (APT) to the QCD analysis of DIS data. In particular, the results of the QCD analysis of a set of `fake' data on the polarized nonsinglet Delta{q3} and the nonsinglet fragmentation function D^{pi+}_{u_v} by using the Q^2-evolution within the APT are considered. The `fake' data are constructed based on parametrization of the polarized PDF and nonsinglet combination of the pion fragmentation functions. We confirm that APT can be successfully applied to QCD analysis of Delta{q_3}(x,Q^2) and D^{pi+}_{u_v}(z,Q^2) and that the inequality Lambda_{APT} > Lambda_{PT} obtained previously for the xF3(x) structure function takes place.
[ { "created": "Tue, 25 Nov 2014 19:19:45 GMT", "version": "v1" }, { "created": "Thu, 15 Jan 2015 12:36:17 GMT", "version": "v2" } ]
2015-01-16
[ [ "Sidorov", "A. V.", "" ], [ "Solovtsova", "O. P.", "" ] ]
We discuss the application of an analytic approach called the analytic perturbation theory (APT) to the QCD analysis of DIS data. In particular, the results of the QCD analysis of a set of `fake' data on the polarized nonsinglet Delta{q3} and the nonsinglet fragmentation function D^{pi+}_{u_v} by using the Q^2-evolution within the APT are considered. The `fake' data are constructed based on parametrization of the polarized PDF and nonsinglet combination of the pion fragmentation functions. We confirm that APT can be successfully applied to QCD analysis of Delta{q_3}(x,Q^2) and D^{pi+}_{u_v}(z,Q^2) and that the inequality Lambda_{APT} > Lambda_{PT} obtained previously for the xF3(x) structure function takes place.
2002.09875
Quan-Yi Hu
Quan-Yi Hu, Ya-Dong Yang and Min-Di Zheng
Revisiting the $B$-physics anomalies in $R$-parity violating MSSM
10 pages, 8 figures, matches to the version published in EPJC
Eur. Phys. J. C 80, 365 (2020)
10.1140/epjc/s10052-020-7940-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, several deviations from the Standard Model predictions in semileptonic decays of $B$-meson might suggest the existence of new physics which would break the lepton-flavour universality. In this work, we have explored the possibility of using muon sneutrinos and right-handed sbottoms to solve these $B$-physics anomalies simultaneously in $R$-parity violating minimal supersymmetric standard model. We find that the photonic penguin induced by exchanging sneutrino can provide sizable lepton flavour universal contribution due to the existence of logarithmic enhancement for the first time. This prompts us to use the two-parameter scenario $(C^{\rm V}_9, \, C^{\rm U}_9)$ to explain $b \to s \ell^+ \ell^-$ anomaly. Finally, the numerical analyses show that the muon sneutrinos and right-handed sbottoms can explain $b \to s \ell^+ \ell^-$ and $R(D^{(\ast)})$ anomalies simultaneously, and satisfy the constraints of other related processes, such as $B \to K^{(\ast)} \nu \bar\nu$ decays, $B_s-\bar B_s$ mixing, $Z$ decays, as well as $D^0 \to \mu^+ \mu^-$, $\tau \to \mu \rho^0$, $B \to \tau \nu$, $D_s \to \tau \nu$, $\tau \to K \nu$, $\tau \to \mu \gamma$, and $\tau \to \mu\mu\mu$ decays.
[ { "created": "Sun, 23 Feb 2020 09:42:23 GMT", "version": "v1" }, { "created": "Wed, 4 Mar 2020 10:29:19 GMT", "version": "v2" }, { "created": "Thu, 7 May 2020 02:53:57 GMT", "version": "v3" } ]
2020-05-20
[ [ "Hu", "Quan-Yi", "" ], [ "Yang", "Ya-Dong", "" ], [ "Zheng", "Min-Di", "" ] ]
In recent years, several deviations from the Standard Model predictions in semileptonic decays of $B$-meson might suggest the existence of new physics which would break the lepton-flavour universality. In this work, we have explored the possibility of using muon sneutrinos and right-handed sbottoms to solve these $B$-physics anomalies simultaneously in $R$-parity violating minimal supersymmetric standard model. We find that the photonic penguin induced by exchanging sneutrino can provide sizable lepton flavour universal contribution due to the existence of logarithmic enhancement for the first time. This prompts us to use the two-parameter scenario $(C^{\rm V}_9, \, C^{\rm U}_9)$ to explain $b \to s \ell^+ \ell^-$ anomaly. Finally, the numerical analyses show that the muon sneutrinos and right-handed sbottoms can explain $b \to s \ell^+ \ell^-$ and $R(D^{(\ast)})$ anomalies simultaneously, and satisfy the constraints of other related processes, such as $B \to K^{(\ast)} \nu \bar\nu$ decays, $B_s-\bar B_s$ mixing, $Z$ decays, as well as $D^0 \to \mu^+ \mu^-$, $\tau \to \mu \rho^0$, $B \to \tau \nu$, $D_s \to \tau \nu$, $\tau \to K \nu$, $\tau \to \mu \gamma$, and $\tau \to \mu\mu\mu$ decays.
hep-ph/9406252
Taku Izubuchi
K. Hagiwara, T. Izubuchi, M. Tanaka and I. Watanabe
Gluon and Charm Distributions in the Photon
59 pages, REVTeX, PostScript figures appended, KEK-TH-376, KEK preprint 93-160, UT--659
Phys.Rev.D51:3197-3219,1995
10.1103/PhysRevD.51.3197
null
hep-ph
null
We study systematically the sensitivity of the photon structure function data on the gluon contents of the photon, by using the leading order Altarelli--Parisi (AP) equations. Charm quark contribution is studied in the quark parton model and by using the massive quark AP equations of Gl\"uck, Hoffmann and Reya. The present photon structure function data are found to allow wide range of gluon distributions in the photon. We give a set of six scale-dependent parton distributions in the photon (WHIT1 to WHIT6), which have systematically different gluon contents. Sensitivity of the structure function at small $x$ and that of the total charm quark production cross section to the effective gluon distribution are discussed.
[ { "created": "Wed, 8 Jun 1994 12:18:49 GMT", "version": "v1" } ]
2010-03-25
[ [ "Hagiwara", "K.", "" ], [ "Izubuchi", "T.", "" ], [ "Tanaka", "M.", "" ], [ "Watanabe", "I.", "" ] ]
We study systematically the sensitivity of the photon structure function data on the gluon contents of the photon, by using the leading order Altarelli--Parisi (AP) equations. Charm quark contribution is studied in the quark parton model and by using the massive quark AP equations of Gl\"uck, Hoffmann and Reya. The present photon structure function data are found to allow wide range of gluon distributions in the photon. We give a set of six scale-dependent parton distributions in the photon (WHIT1 to WHIT6), which have systematically different gluon contents. Sensitivity of the structure function at small $x$ and that of the total charm quark production cross section to the effective gluon distribution are discussed.
hep-ph/9501240
Paolo Nason
G. Altarelli (CERN), P. Nason (CERN), G. Ridolfi (CERN).
A Study of Ultraviolet Renormalon Ambiguities in the Determination of $\as$ from $\tau$ Decay
32 pages, epsfig.sty.
Z.Phys. C68 (1995) 257-268
10.1007/BF01566673
CERN-TH.7537/94, GeF-TH-1/95 and IFUM 489/FT
hep-ph
null
The divergent large-order behaviour of the perturbative series relevant for the determination of $\as$ from $\tau$ decay is controlled by the leading ultraviolet (UV) renormalon. Even in the absence of the first infrared (IR) renormalon, an ambiguity of order $\Lambda^2/m_\tau^2$ is introduced. We make a quantitative study of the practical implications of this ambiguity. We discuss the magnitude of UV renormalon corrections obtained in the large-$N_f$ limit, which, although unrealistic, is nevertheless interesting to some extent. We then study a number of improved approximants for the perturbative series, based on a change of variable in the Borel representation, such as to displace the leading UV renormalon singularity at a larger distance from the origin than the first IR renormalon. The spread of the resulting values of $\as(m^2_\tau)$ obtained by different approximants, at different renormalization scales, is exhibited as a measure of the underlying ambiguities. Finally, on the basis of mathematical models, we discuss the prospects of an actual improvement, given the signs and magnitudes of the computed coefficients, the size of $\as(m^2_\tau)$ and what is known of the asymptotic properties of the series. Our conclusion is that a realistic estimate of the theoretical error cannot go below $\delta\as(m^2_\tau) \sim \pm 0.060$, or $\delta\as(m^2_{\sss Z}) \sim \pm 0.006$.
[ { "created": "Mon, 9 Jan 1995 11:23:47 GMT", "version": "v1" } ]
2016-09-01
[ [ "Altarelli", "G.", "", "CERN" ], [ "Nason", "P.", "", "CERN" ], [ "Ridolfi", "G.", "", "CERN" ], [ ".", "", "" ] ]
The divergent large-order behaviour of the perturbative series relevant for the determination of $\as$ from $\tau$ decay is controlled by the leading ultraviolet (UV) renormalon. Even in the absence of the first infrared (IR) renormalon, an ambiguity of order $\Lambda^2/m_\tau^2$ is introduced. We make a quantitative study of the practical implications of this ambiguity. We discuss the magnitude of UV renormalon corrections obtained in the large-$N_f$ limit, which, although unrealistic, is nevertheless interesting to some extent. We then study a number of improved approximants for the perturbative series, based on a change of variable in the Borel representation, such as to displace the leading UV renormalon singularity at a larger distance from the origin than the first IR renormalon. The spread of the resulting values of $\as(m^2_\tau)$ obtained by different approximants, at different renormalization scales, is exhibited as a measure of the underlying ambiguities. Finally, on the basis of mathematical models, we discuss the prospects of an actual improvement, given the signs and magnitudes of the computed coefficients, the size of $\as(m^2_\tau)$ and what is known of the asymptotic properties of the series. Our conclusion is that a realistic estimate of the theoretical error cannot go below $\delta\as(m^2_\tau) \sim \pm 0.060$, or $\delta\as(m^2_{\sss Z}) \sim \pm 0.006$.
2011.02469
Andrej Arbuzov
M.K. Volkov, A.B. Arbuzov, K. Nurlan, and A.A. Pivovarov
Fixing the vector coupling constant $g_\rho = 5.0$ in the NJL model and final-state interactions in processes $\rho \to e^+e^-[\mu^+\mu^-]$, $\rho \to \pi^+\pi^-$, $\tau \to \pi^-\pi^0\nu_\tau$, and $e^+e^-\to\pi^+\pi^-$
4 pages, 6 figures, misprints are corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility to use the width of the decay $\rho \to e^{+}e^{-}$ to fix the input parameter $g_\rho=5.0$ of the $SU(2) \times SU(2)$ chiral-symmetric Nambu--Jona-Lasinio model is discussed. It is shown that for a consistent simultaneous description of the processes $\rho \to e^{+}e^{-}$, $\rho \to \pi^{+}\pi^{-}$, $\tau^{-} \to \pi^{-}\pi^{0} \nu_{\tau}$, and $e^{+}e^{-} \to \pi^{+}\pi^{-}$ can be constructed. Taking into account the interaction of pions in the final state appears to be important. The obtained theoretical results for the considered processes are in a satisfactory agreement with experimental data.
[ { "created": "Wed, 4 Nov 2020 18:38:37 GMT", "version": "v1" }, { "created": "Thu, 5 Nov 2020 12:52:10 GMT", "version": "v2" } ]
2020-11-06
[ [ "Volkov", "M. K.", "" ], [ "Arbuzov", "A. B.", "" ], [ "Nurlan", "K.", "" ], [ "Pivovarov", "A. A.", "" ] ]
The possibility to use the width of the decay $\rho \to e^{+}e^{-}$ to fix the input parameter $g_\rho=5.0$ of the $SU(2) \times SU(2)$ chiral-symmetric Nambu--Jona-Lasinio model is discussed. It is shown that for a consistent simultaneous description of the processes $\rho \to e^{+}e^{-}$, $\rho \to \pi^{+}\pi^{-}$, $\tau^{-} \to \pi^{-}\pi^{0} \nu_{\tau}$, and $e^{+}e^{-} \to \pi^{+}\pi^{-}$ can be constructed. Taking into account the interaction of pions in the final state appears to be important. The obtained theoretical results for the considered processes are in a satisfactory agreement with experimental data.
1707.02061
Toshitaka Tatsumi
Toshitaka Tatsumi
Inhomogeneous Chiral Phase in Quark Matter
8 pages,3 figures, Proc. of QCS2017 (Kyoto, Japan)
null
10.7566/JPSCP.20.011008
null
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent development of inhomogeneous chiral phase in Kyoto group is briefly reviewed. First, the nesting effect of the Fermi surface is emphasized as a key mechanism leading to inhomogeneous chiral phase. After introduction of inhomogeneous chiral phase, some topological aspect is discussed in 1+1 dimensions and in the presence of the magnetic field in 1+3 dimensions. Spectral asymmetry gives rise to anomalous quark number and is closely related to chiral anomaly. It may induce spontaneous magnetization and a novel Lifshitz point may appear on the line $\mu=0$. Some astronomical implications are briefly discussed. Finally, the effects of the fluctuations around the order parameter are discussed; the propagator of the fluctuations exhibits a singularity at finite momentum and changes the properties of the phase transition through loop diagrams.
[ { "created": "Fri, 7 Jul 2017 07:39:50 GMT", "version": "v1" } ]
2018-02-14
[ [ "Tatsumi", "Toshitaka", "" ] ]
Recent development of inhomogeneous chiral phase in Kyoto group is briefly reviewed. First, the nesting effect of the Fermi surface is emphasized as a key mechanism leading to inhomogeneous chiral phase. After introduction of inhomogeneous chiral phase, some topological aspect is discussed in 1+1 dimensions and in the presence of the magnetic field in 1+3 dimensions. Spectral asymmetry gives rise to anomalous quark number and is closely related to chiral anomaly. It may induce spontaneous magnetization and a novel Lifshitz point may appear on the line $\mu=0$. Some astronomical implications are briefly discussed. Finally, the effects of the fluctuations around the order parameter are discussed; the propagator of the fluctuations exhibits a singularity at finite momentum and changes the properties of the phase transition through loop diagrams.
2109.04852
Gabriel Massoni Salla
Daniele Barducci, Enrico Bertuzzo, Giovanni Grilli di Cortona, Gabriel M. Salla
Dark Photon bounds in the dark EFT
22 pages; v2: Expanded discussion on the UV completion, version accepted for publication in JHEP
JHEP 12 (2021) 081
10.1007/JHEP12(2021)081
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark photons are massive abelian gauge bosons that interact with ordinary photons via a kinetic mixing with the hypercharge field strength tensor. This theory is probed by a variety of different experiments and limits are set on a combination of the dark photon mass and kinetic mixing parameter. These limits can however be strongly modified by the presence of additional heavy degrees of freedom. Using the framework of dark effective field theory, we study how robust are the current experimental bounds when these new states are present. We focus in particular on the possible existence of a dark dipole interaction between the Standard Model leptons and the dark photon. We show that, under certain assumptions, the presence of a dark dipole modifies existing supernov{\ae} bounds for cut-off scales up to $\mathcal{O}(10 - 100~\text{TeV})$. On the other hand, terrestrial experiments, such as LSND and E137, can probe cut-off scales up to $\mathcal{O}(3~\text{TeV})$. For the latter experiment we highlight that the bound may extend down to vanishing kinetic mixing.
[ { "created": "Fri, 10 Sep 2021 13:06:25 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 2021 12:30:53 GMT", "version": "v2" } ]
2022-05-17
[ [ "Barducci", "Daniele", "" ], [ "Bertuzzo", "Enrico", "" ], [ "di Cortona", "Giovanni Grilli", "" ], [ "Salla", "Gabriel M.", "" ] ]
Dark photons are massive abelian gauge bosons that interact with ordinary photons via a kinetic mixing with the hypercharge field strength tensor. This theory is probed by a variety of different experiments and limits are set on a combination of the dark photon mass and kinetic mixing parameter. These limits can however be strongly modified by the presence of additional heavy degrees of freedom. Using the framework of dark effective field theory, we study how robust are the current experimental bounds when these new states are present. We focus in particular on the possible existence of a dark dipole interaction between the Standard Model leptons and the dark photon. We show that, under certain assumptions, the presence of a dark dipole modifies existing supernov{\ae} bounds for cut-off scales up to $\mathcal{O}(10 - 100~\text{TeV})$. On the other hand, terrestrial experiments, such as LSND and E137, can probe cut-off scales up to $\mathcal{O}(3~\text{TeV})$. For the latter experiment we highlight that the bound may extend down to vanishing kinetic mixing.
hep-ph/9607271
Debajyoti Choudhury
Debajyoti Choudhury (MPI, Munich) and Maria Krawczyk (ITP, Warsaw)
Light Neutral Higgs Bosons at the Low Energy $\gamma \gamma $ Collider
8 pages (LaTeX), 7 figures (postscript versions included as a uuencoded tarred gzipped file)
Phys.Rev.D55:2774-2778,1997
10.1103/PhysRevD.55.2774
MPI-PTh/96-46, IFT-96/13
hep-ph
null
A light neutral Higgs boson in the framework of the general two Higgs doublet model (2HDM) is not excluded by existing data. We point out that it can be looked for at the proposed low energy $\gamma \gamma$ collider. Failure to detect one may lead to important limits on the parameters of the general 2HDM.
[ { "created": "Tue, 9 Jul 1996 21:05:53 GMT", "version": "v1" } ]
2011-04-15
[ [ "Choudhury", "Debajyoti", "", "MPI, Munich" ], [ "Krawczyk", "Maria", "", "ITP, Warsaw" ] ]
A light neutral Higgs boson in the framework of the general two Higgs doublet model (2HDM) is not excluded by existing data. We point out that it can be looked for at the proposed low energy $\gamma \gamma$ collider. Failure to detect one may lead to important limits on the parameters of the general 2HDM.
1103.2122
Markus Schulze
Kirill Melnikov and Markus Schulze
Top quark spin correlations at the Tevatron and the LHC
6 pages, 4 figures; reference added
Phys.Lett.B700:17-20,2011
10.1016/j.physletb.2011.04.043
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spin correlations of top quarks produced in hadron collisions have not been observed experimentally with large significance. In this Letter, we propose a new variable that may enable demonstration of the existence of spin correlations with 3-4 sigma significance using just a few hundred dilepton events both at the Tevatron and the LHC. Such number of dilepton events has been observed at the Tevatron. At the LHC, it will become available once integrated luminosity of a few hundred inverse picobarns is collected.
[ { "created": "Thu, 10 Mar 2011 20:52:37 GMT", "version": "v1" }, { "created": "Mon, 21 Mar 2011 15:11:33 GMT", "version": "v2" } ]
2015-03-19
[ [ "Melnikov", "Kirill", "" ], [ "Schulze", "Markus", "" ] ]
Spin correlations of top quarks produced in hadron collisions have not been observed experimentally with large significance. In this Letter, we propose a new variable that may enable demonstration of the existence of spin correlations with 3-4 sigma significance using just a few hundred dilepton events both at the Tevatron and the LHC. Such number of dilepton events has been observed at the Tevatron. At the LHC, it will become available once integrated luminosity of a few hundred inverse picobarns is collected.
hep-ph/0612292
Mario E. Gomez
John Ellis, Mario E. Gomez, Smaragda Lola
CP and Lepton-Number Violation in GUT Neutrino Models with Abelian Flavour Symmetries
30 pages, 6 figures
JHEP 0707:052,2007
10.1088/1126-6708/2007/07/052
CERN-PH-TH/2006-181
hep-ph
null
We study the possible magnitudes of CP and lepton-number-violating quantities in specific GUT models of massive neutrinos with different Abelian flavour groups, taking into account experimental constraints and requiring successful leptogenesis. We discuss SU(5) and flipped SU(5) models that are consistent with the present data on neutrino mixing and upper limits on the violations of charged-lepton flavours and explore their predictions for the CP-violating oscillation and Majorana phases. In particular, we discuss string-derived flipped SU(5) models with selection rules that modify the GUT structure and provide additional constraints on the operators, which are able to account for the magnitudes of some of the coefficients that are often set as arbitrary parameters in generic Abelian models.
[ { "created": "Thu, 21 Dec 2006 22:23:08 GMT", "version": "v1" }, { "created": "Wed, 18 Jul 2007 22:48:28 GMT", "version": "v2" } ]
2009-09-11
[ [ "Ellis", "John", "" ], [ "Gomez", "Mario E.", "" ], [ "Lola", "Smaragda", "" ] ]
We study the possible magnitudes of CP and lepton-number-violating quantities in specific GUT models of massive neutrinos with different Abelian flavour groups, taking into account experimental constraints and requiring successful leptogenesis. We discuss SU(5) and flipped SU(5) models that are consistent with the present data on neutrino mixing and upper limits on the violations of charged-lepton flavours and explore their predictions for the CP-violating oscillation and Majorana phases. In particular, we discuss string-derived flipped SU(5) models with selection rules that modify the GUT structure and provide additional constraints on the operators, which are able to account for the magnitudes of some of the coefficients that are often set as arbitrary parameters in generic Abelian models.
1101.3822
Alexey A. Petrov
Alexey A Petrov
CP-violation in charm
7 pages, presented at the 6th International Workshop on the CKM Unitarity Triangle (CKM2010), University of Warwick, UK, 6-10 September 2010
null
null
WSU-HEP-1004
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review recent results in theoretical and experimental analyses of CP-violation in charmed transitions, paying particular attention to constraints on parameters of beyond the Standard Model interactions.
[ { "created": "Thu, 20 Jan 2011 05:18:17 GMT", "version": "v1" } ]
2011-01-21
[ [ "Petrov", "Alexey A", "" ] ]
I review recent results in theoretical and experimental analyses of CP-violation in charmed transitions, paying particular attention to constraints on parameters of beyond the Standard Model interactions.
hep-ph/9807314
Zhang
Meng Ta-chung, R. Rittel, K. Tabelow and Zhang Yang
Formation of color-singlet gluon-clusters and inelastic diffractive scattering. Part II: Derivation of the $t$- and $M_x^2/s$-dependence of cross-sections in the SOC-approach
21 pages, 4 PS figures
null
null
null
hep-ph
null
The $t$-dependence and the $(M_x^2/s)$-dependence of the double differential cross-sections for inelastic diffractive scattering off proton-target are discussed. Here $t$ stands for the four-momentum-transfer squared, $M_x$ for the missing mass, and $\sqrt{s}$ for the total c.m.s. energy. It is shown, that the space-time properties of the color-singlet gluon-clusters due to SOC, discussed in Part I, lead to simple analytical formulae for $d^2\sigma/dt d(M_x^2/s)$ and for $d\sigma/dt$, and that the obtained results are in good agreement with the existing data. Further experiments are suggested.
[ { "created": "Thu, 9 Jul 1998 18:27:14 GMT", "version": "v1" }, { "created": "Wed, 15 Jul 1998 15:22:35 GMT", "version": "v2" }, { "created": "Wed, 10 Feb 1999 17:19:19 GMT", "version": "v3" } ]
2007-05-23
[ [ "Ta-chung", "Meng", "" ], [ "Rittel", "R.", "" ], [ "Tabelow", "K.", "" ], [ "Yang", "Zhang", "" ] ]
The $t$-dependence and the $(M_x^2/s)$-dependence of the double differential cross-sections for inelastic diffractive scattering off proton-target are discussed. Here $t$ stands for the four-momentum-transfer squared, $M_x$ for the missing mass, and $\sqrt{s}$ for the total c.m.s. energy. It is shown, that the space-time properties of the color-singlet gluon-clusters due to SOC, discussed in Part I, lead to simple analytical formulae for $d^2\sigma/dt d(M_x^2/s)$ and for $d\sigma/dt$, and that the obtained results are in good agreement with the existing data. Further experiments are suggested.
1706.08664
David Latimer
Kyle M. Whitcomb and David C. Latimer
Scattering from a quantum anapole at low energies
null
Am. J. Phys. 85, 932 (2017)
10.1119/1.5003377
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In quantum field theory, the photon-fermion vertex can be described in terms of four form factors which encode the static electromagnetic properties of the particle, namely its charge, magnetic dipole moment, electric dipole moment, and anapole moment. For Majorana fermions, only the anapole moment can be nonzero, a consequence of the fact that these particles are their own antiparticles. Using the framework of quantum field theory, we perform a scattering calculation which probes the anapole moment with a spinless charged particle. In the limit of low-momentum transfer, we confirm that the anapole can be classically likened to a point-like toroidal solenoid whose magnetic field is confined to the origin. Such a toroidal current distribution can be used to demonstrate the Aharonov-Bohm effect. We find that, in the non-relativistic limit, our scattering cross section agrees with a quantum mechanical computation of the cross section for a spinless current scattered by an infinitesimally thin toroidal solenoid. Our presentation is geared toward advanced undergraduate or beginning graduate students. This work serves as an introduction to the anapole moment and also provides an example of how one can develop an understanding of a particle's electromagnetic properties in quantum field theory.
[ { "created": "Tue, 27 Jun 2017 04:04:11 GMT", "version": "v1" } ]
2017-11-22
[ [ "Whitcomb", "Kyle M.", "" ], [ "Latimer", "David C.", "" ] ]
In quantum field theory, the photon-fermion vertex can be described in terms of four form factors which encode the static electromagnetic properties of the particle, namely its charge, magnetic dipole moment, electric dipole moment, and anapole moment. For Majorana fermions, only the anapole moment can be nonzero, a consequence of the fact that these particles are their own antiparticles. Using the framework of quantum field theory, we perform a scattering calculation which probes the anapole moment with a spinless charged particle. In the limit of low-momentum transfer, we confirm that the anapole can be classically likened to a point-like toroidal solenoid whose magnetic field is confined to the origin. Such a toroidal current distribution can be used to demonstrate the Aharonov-Bohm effect. We find that, in the non-relativistic limit, our scattering cross section agrees with a quantum mechanical computation of the cross section for a spinless current scattered by an infinitesimally thin toroidal solenoid. Our presentation is geared toward advanced undergraduate or beginning graduate students. This work serves as an introduction to the anapole moment and also provides an example of how one can develop an understanding of a particle's electromagnetic properties in quantum field theory.
2002.03590
Sinan Kuday
I. Hos, S. Kuday and H. Sayg{\i}n
The Observation of Jet Azimuthal Angular Decorrelation at FCC-ep
11 pages, 15 figures, 3 tables. Accepted by IJMPA in 13/02/2023
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Higher collision energies at future colliders may eventually lead to the falsification of standard fixed-order perturbation theory and linear evolutions due to non-linear structure of QCD at small-x. New physics researches that is strictly based on accurate jet measurements will undoubtedly have this observation known as BFKL effect via angular jet decorrelations taking into account the Mueller-Navelet jets. As one of the frontier colliders, FCC-ep, has a great observation potential on parton densities through asymmetrical collisions. We aim to test the observability of azimuthal angular jet decorrelations with the recent event generators (HERWIG, PYTHIA) at the particle level for FCC-ep centre of mass energies 3.5 TeV in proton-electron collisions. Jets are reconstructed by the Anti-kT algorithm (R = 0.5), with $p_{T} > 35 GeV$ and selected in the range of |y|<6. Relevant rapidity regions has been analyzed with the azimuthal-angle difference between Mueller-Navelet Jets (${\Delta}{\Phi}$) in the rapidity seperation (${\Delta}y $) and the distributions of cosn(${\pi}-{\Delta}{\Phi}$) are presented in comparison as the result.
[ { "created": "Mon, 10 Feb 2020 08:12:46 GMT", "version": "v1" }, { "created": "Wed, 2 Sep 2020 09:12:32 GMT", "version": "v2" }, { "created": "Mon, 13 Feb 2023 12:41:44 GMT", "version": "v3" } ]
2023-02-14
[ [ "Hos", "I.", "" ], [ "Kuday", "S.", "" ], [ "Saygın", "H.", "" ] ]
Higher collision energies at future colliders may eventually lead to the falsification of standard fixed-order perturbation theory and linear evolutions due to non-linear structure of QCD at small-x. New physics researches that is strictly based on accurate jet measurements will undoubtedly have this observation known as BFKL effect via angular jet decorrelations taking into account the Mueller-Navelet jets. As one of the frontier colliders, FCC-ep, has a great observation potential on parton densities through asymmetrical collisions. We aim to test the observability of azimuthal angular jet decorrelations with the recent event generators (HERWIG, PYTHIA) at the particle level for FCC-ep centre of mass energies 3.5 TeV in proton-electron collisions. Jets are reconstructed by the Anti-kT algorithm (R = 0.5), with $p_{T} > 35 GeV$ and selected in the range of |y|<6. Relevant rapidity regions has been analyzed with the azimuthal-angle difference between Mueller-Navelet Jets (${\Delta}{\Phi}$) in the rapidity seperation (${\Delta}y $) and the distributions of cosn(${\pi}-{\Delta}{\Phi}$) are presented in comparison as the result.
hep-ph/9910272
Nathan Isgur
Nathan Isgur (Jefferson Lab)
Meson-like Baryons and the Spin-Orbit Puzzle
24 pages, 4 figures
Phys.Rev.D62:014025,2000
10.1103/PhysRevD.62.014025
JLAB-THY-99-30
hep-ph
null
I describe a special class of meson-like \Lambda_Q excited states and present evidence supporting the similarity of their spin-independent spectra to those of mesons. I then examine spin-dependent forces in these baryons, showing that predicted effects of spin-orbit forces are small for them for the same reason they are small for the analogous mesons: a fortuitous cancellation between large spin-orbit forces due to one-gluon-exchange and equally large inverted spin-orbit forces due to Thomas precession in the confining potential. In addition to eliminating the baryon spin-orbit puzzle in these states, this solution provides a new perspective on spin-orbit forces in all baryons.
[ { "created": "Thu, 7 Oct 1999 17:23:26 GMT", "version": "v1" } ]
2014-11-17
[ [ "Isgur", "Nathan", "", "Jefferson Lab" ] ]
I describe a special class of meson-like \Lambda_Q excited states and present evidence supporting the similarity of their spin-independent spectra to those of mesons. I then examine spin-dependent forces in these baryons, showing that predicted effects of spin-orbit forces are small for them for the same reason they are small for the analogous mesons: a fortuitous cancellation between large spin-orbit forces due to one-gluon-exchange and equally large inverted spin-orbit forces due to Thomas precession in the confining potential. In addition to eliminating the baryon spin-orbit puzzle in these states, this solution provides a new perspective on spin-orbit forces in all baryons.
1404.3073
Bin Wang
Bin Wang, Zhu-Fang Cui, Wei-Min Sun and Hong-Shi Zong
A model study of the chiral phase diagram of QCD
15 pages, 6 figures. Few-Body Systems 2013
null
10.1007/s00601-013-0737-7
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the chiral phase transition of QCD at finite temperature and density by using the rank-2 confining separable gluon propagator model in the framework of Dyson-Schwinger Equations. The critical end point is located at (T_CEP, {\mu}_CEP) = (69 MeV, 270.3 MeV). It is also found that the first order phase transition might not end at one point, but experiences a two-phase coexisting meta-stable state. A comparison with the results in the previous literature is given.
[ { "created": "Fri, 11 Apr 2014 11:10:32 GMT", "version": "v1" } ]
2016-11-02
[ [ "Wang", "Bin", "" ], [ "Cui", "Zhu-Fang", "" ], [ "Sun", "Wei-Min", "" ], [ "Zong", "Hong-Shi", "" ] ]
In this paper we study the chiral phase transition of QCD at finite temperature and density by using the rank-2 confining separable gluon propagator model in the framework of Dyson-Schwinger Equations. The critical end point is located at (T_CEP, {\mu}_CEP) = (69 MeV, 270.3 MeV). It is also found that the first order phase transition might not end at one point, but experiences a two-phase coexisting meta-stable state. A comparison with the results in the previous literature is given.
hep-ph/9809357
Durmus Ali Demir
D. A. Demir, N. K. Pak
One-Loop Effects in Supergravity Models with an Additional U(1)
16 pages, 6 postscript figures
Phys.Rev. D57 (1998) 6609-6617
10.1103/PhysRevD.57.6609
null
hep-ph
null
For an Abelian extended Supergravity model, we investigate some important low energy parameters: \tan\beta, Z-Z' mixing angle, lightest CP-even Higgs mass bound, Z' mass, and effective \mu parameter. By integrating the RGE's from string scale down to the weak scale we constuct the scalar potential, and analyze the quantities above at the tree- and one-loop levels by including the contributions of top squarks and top quark in the effective potential. PACS: 04.65.+e, 12.60.Jv
[ { "created": "Sun, 13 Sep 1998 13:54:35 GMT", "version": "v1" } ]
2009-10-31
[ [ "Demir", "D. A.", "" ], [ "Pak", "N. K.", "" ] ]
For an Abelian extended Supergravity model, we investigate some important low energy parameters: \tan\beta, Z-Z' mixing angle, lightest CP-even Higgs mass bound, Z' mass, and effective \mu parameter. By integrating the RGE's from string scale down to the weak scale we constuct the scalar potential, and analyze the quantities above at the tree- and one-loop levels by including the contributions of top squarks and top quark in the effective potential. PACS: 04.65.+e, 12.60.Jv
1504.02409
Jeremie Quevillon
Aleksandra Drozd, John Ellis, J\'er\'emie Quevillon and Tevong You
Comparing EFT and Exact One-Loop Analyses of Non-Degenerate Stops
25 pages, v2 corrects three equations and some typos, with plot results and conclusions unchanged
null
null
KCL-PH-TH/2015-17, LCTS/2015-08, CERN-PH-TH/2015-072
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a universal approach to the one-loop effective field theory (EFT) using the Covariant Derivative Expansion (CDE) method. We generalise previous results to include broader classes of UV models, showing how expressions previously obtained assuming degenerate heavy-particle masses can be extended to non-degenerate cases. We apply our method to the general MSSM with non-degenerate stop squarks, illustrating our approach with calculations of the coefficients of dimension-6 operators contributing to the $hgg$ and $h\gamma\gamma$ couplings, and comparing with exact calculations of one-loop Feynman diagrams. We then use present and projected future sensitivities to these operator coefficients to obtain present and possible future indirect constraints on stop masses. The current sensitivity is already comparable to that of direct LHC searches, and future FCC-ee measurements could be sensitive to stop masses above a TeV. The universality of our one-loop EFT approach facilitates extending these constraints to a broader class of UV models.
[ { "created": "Thu, 9 Apr 2015 18:17:50 GMT", "version": "v1" }, { "created": "Wed, 10 Feb 2016 18:07:42 GMT", "version": "v2" } ]
2016-02-11
[ [ "Drozd", "Aleksandra", "" ], [ "Ellis", "John", "" ], [ "Quevillon", "Jérémie", "" ], [ "You", "Tevong", "" ] ]
We develop a universal approach to the one-loop effective field theory (EFT) using the Covariant Derivative Expansion (CDE) method. We generalise previous results to include broader classes of UV models, showing how expressions previously obtained assuming degenerate heavy-particle masses can be extended to non-degenerate cases. We apply our method to the general MSSM with non-degenerate stop squarks, illustrating our approach with calculations of the coefficients of dimension-6 operators contributing to the $hgg$ and $h\gamma\gamma$ couplings, and comparing with exact calculations of one-loop Feynman diagrams. We then use present and projected future sensitivities to these operator coefficients to obtain present and possible future indirect constraints on stop masses. The current sensitivity is already comparable to that of direct LHC searches, and future FCC-ee measurements could be sensitive to stop masses above a TeV. The universality of our one-loop EFT approach facilitates extending these constraints to a broader class of UV models.
1806.09508
Sangjun Lee
Kiwoon Choi, Sangjun Lee, Hyeonseok Seong, Seokhoon Yun
Gamma-ray spectral modulations induced by photon-ALP-dark photon oscillations
12 pages, 3 figures. v3: realization of background dark photon gauge fields included; v4: PRD accepted version, figures updated, chi-square analysis presented in Sec. III, observational constraints revisited in Sec. IV C and D
Phys. Rev. D 101, 043007 (2020)
10.1103/PhysRevD.101.043007
CTPU-PTC-18-18, KIAS-P19027
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently it has been noticed that the Fermi-LAT data of gamma-rays from some galactic pulsars and supernova remnants reveal spectral modulations that might be explained by the conversion of photons to ALPs (axion-like particles) induced by the conventional ALP coupling to photon in the presence of galactic magnetic fields. However the corresponding ALP mass and coupling are in a severe tension with the observational constraints from CAST, SN1987A, and other gamma-ray observations. Motivated by this, we examine an alternative possibility that those spectral modulations are explained by other type of ALP coupling involving both the ordinary photon and a massless dark photon, when nonzero background dark photon gauge fields are assumed. We find that our scheme results in oscillations among the photon, ALP, and dark photon, which can explain the gamma-ray spectral modulations of galactic pulsars or supernova remnants, while satisfying the known observational constraints.
[ { "created": "Mon, 25 Jun 2018 14:53:51 GMT", "version": "v1" }, { "created": "Wed, 27 Jun 2018 07:59:58 GMT", "version": "v2" }, { "created": "Fri, 3 May 2019 06:57:10 GMT", "version": "v3" }, { "created": "Sun, 17 May 2020 06:08:31 GMT", "version": "v4" } ]
2020-05-19
[ [ "Choi", "Kiwoon", "" ], [ "Lee", "Sangjun", "" ], [ "Seong", "Hyeonseok", "" ], [ "Yun", "Seokhoon", "" ] ]
Recently it has been noticed that the Fermi-LAT data of gamma-rays from some galactic pulsars and supernova remnants reveal spectral modulations that might be explained by the conversion of photons to ALPs (axion-like particles) induced by the conventional ALP coupling to photon in the presence of galactic magnetic fields. However the corresponding ALP mass and coupling are in a severe tension with the observational constraints from CAST, SN1987A, and other gamma-ray observations. Motivated by this, we examine an alternative possibility that those spectral modulations are explained by other type of ALP coupling involving both the ordinary photon and a massless dark photon, when nonzero background dark photon gauge fields are assumed. We find that our scheme results in oscillations among the photon, ALP, and dark photon, which can explain the gamma-ray spectral modulations of galactic pulsars or supernova remnants, while satisfying the known observational constraints.
1506.01410
Nobuchika Okada
Nobuchika Okada, Qaisar Shafi
$\mu$-Term Hybrid Inflation and Split Supersymmetry
10 pages, 5 figures, some minor changes
null
10.1016/j.physletb.2017.11.015
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider $\mu$-term hybrid inflation which, in its minimal format with gravity mediated supersymmetry breaking, leads to split supersymmetry. The MSSM $\mu$-term in this framework is larger than the gravitino mass $m_G$, and successful inflation requires $m_G$ (and hence also $|\mu|$) $\gtrsim 5 \times 10^7$ GeV, such that the gravitino decays before the LSP neutralino freezes out. Assuming universal scalar masses of the same order as $m_G$, this leads to split supersymmetry. The LSP wino with mass $\simeq$ 2 TeV is a plausible dark matter candidate, the gluino may be accessible at the LHC, and the MSSM parameter $\tan \beta \simeq 1.7$ in order to be compatible with the measured Higgs boson mass. The tensor-to-scalar ratio $r$, a canonical measure of gravity waves, can be as high as $0.001$.
[ { "created": "Wed, 3 Jun 2015 21:13:38 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 2015 14:29:41 GMT", "version": "v2" } ]
2018-02-01
[ [ "Okada", "Nobuchika", "" ], [ "Shafi", "Qaisar", "" ] ]
We consider $\mu$-term hybrid inflation which, in its minimal format with gravity mediated supersymmetry breaking, leads to split supersymmetry. The MSSM $\mu$-term in this framework is larger than the gravitino mass $m_G$, and successful inflation requires $m_G$ (and hence also $|\mu|$) $\gtrsim 5 \times 10^7$ GeV, such that the gravitino decays before the LSP neutralino freezes out. Assuming universal scalar masses of the same order as $m_G$, this leads to split supersymmetry. The LSP wino with mass $\simeq$ 2 TeV is a plausible dark matter candidate, the gluino may be accessible at the LHC, and the MSSM parameter $\tan \beta \simeq 1.7$ in order to be compatible with the measured Higgs boson mass. The tensor-to-scalar ratio $r$, a canonical measure of gravity waves, can be as high as $0.001$.
1312.1631
Ernst Trojan
Ernst Trojan and George V. Vlasov
Reply to Comment on "Acoustics of tachyon Fermi gas"
4 pages, 1 suppl. figure
Phys. Rev. D 85, 128502 (2012)
10.1103/PhysRevD.85.128502
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a paper appearing in this issue of Physical Review D, Burmistrov raises some critical comments on the thermodynamics of a cold tachyon Fermi gas [E. Trojan and G. V. Vlasov, Phys. Rev. D 83, 124013 (2011)]. However, apart from any possible theoretical speculation, there are the basic physical principles to test the theory.
[ { "created": "Thu, 5 Dec 2013 17:55:28 GMT", "version": "v1" } ]
2015-06-18
[ [ "Trojan", "Ernst", "" ], [ "Vlasov", "George V.", "" ] ]
In a paper appearing in this issue of Physical Review D, Burmistrov raises some critical comments on the thermodynamics of a cold tachyon Fermi gas [E. Trojan and G. V. Vlasov, Phys. Rev. D 83, 124013 (2011)]. However, apart from any possible theoretical speculation, there are the basic physical principles to test the theory.
hep-ph/0110329
Dmitri Ryzhikh
D. A. Ryzhikh (ITEP, Moscow, Russia), K. A. Ter-Martirosyan (ITEP, Moscow, Russia)
Neutrino Mixing and Leptonic CP Phase in Neutrino Oscillations
null
JETP Lett. 74 (2001) 139-143; Erratum-ibid. 76 (2002) 401
10.1134/1.1410217
null
hep-ph
null
Oscillations of the Dirac neutrinos of three generations in vacuum are considered with allowance made for the effect of the CP-violating leptonic phase (analogue of the quark CP phase) in the lepton mixing matrix. The general formulas for the probabilities of neutrino transition from one sort to another in oscillations are obtained as functions of three mixing angles and the CP phase. It is found that the leptonic CP phase can, in principle, be reconstructed by measuring the oscillation-averaged probabilities of neutrino transition from one sort to another. The manifestation of the CP phase as a deviation of the probabilities of direct processes from those of inverse processes is an effect that is practically unobservable as yet.
[ { "created": "Thu, 25 Oct 2001 11:17:46 GMT", "version": "v1" }, { "created": "Mon, 12 Nov 2001 14:46:45 GMT", "version": "v2" }, { "created": "Wed, 14 Nov 2001 10:43:30 GMT", "version": "v3" } ]
2009-11-07
[ [ "Ryzhikh", "D. A.", "", "ITEP, Moscow, Russia" ], [ "Ter-Martirosyan", "K. A.", "", "ITEP,\n Moscow, Russia" ] ]
Oscillations of the Dirac neutrinos of three generations in vacuum are considered with allowance made for the effect of the CP-violating leptonic phase (analogue of the quark CP phase) in the lepton mixing matrix. The general formulas for the probabilities of neutrino transition from one sort to another in oscillations are obtained as functions of three mixing angles and the CP phase. It is found that the leptonic CP phase can, in principle, be reconstructed by measuring the oscillation-averaged probabilities of neutrino transition from one sort to another. The manifestation of the CP phase as a deviation of the probabilities of direct processes from those of inverse processes is an effect that is practically unobservable as yet.
1511.09457
Thorben Graf
Thorben Graf, Juergen Schaffner-Bielich, Eduardo S. Fraga
Perturbative thermodynamics at nonzero isospin density for cold QCD
V2: Minor modifications; 5 pages, 6 figures
Phys. Rev. D 93, 085030 (2016)
10.1103/PhysRevD.93.085030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use next-to-leading-order in perturbation theory to investigate the effects of a finite isospin density on the thermodynamics of cold strongly interacting matter. Our results include nonzero quark masses and are compared to lattice data.
[ { "created": "Mon, 30 Nov 2015 20:29:12 GMT", "version": "v1" }, { "created": "Tue, 2 Aug 2016 16:41:23 GMT", "version": "v2" } ]
2016-08-03
[ [ "Graf", "Thorben", "" ], [ "Schaffner-Bielich", "Juergen", "" ], [ "Fraga", "Eduardo S.", "" ] ]
We use next-to-leading-order in perturbation theory to investigate the effects of a finite isospin density on the thermodynamics of cold strongly interacting matter. Our results include nonzero quark masses and are compared to lattice data.
hep-ph/9408400
Erwin Mirkes
J.H. K"uhn and E. Mirkes
Structure Functions and Distributions in Semileptonic Tau Decays
Presented by E. Mirkes at DPF94 Meeting, Albuquerque, New Mexico, August 2-6,1994. 5 pages (LaTex), 2 uuencoded figures appended, MAD/PH/848
null
null
null
hep-ph
null
Semileptonic decays of polarized $\tau$ leptons are investigated. The most general angular distribution of three meson final states ($\tau\rightarrow \pi\pi\nu,\,K\pi\nu,\, \pi\pi\pi\nu,\\ \,K\pi\pi\nu,\, KK\pi\nu,\, KKK\nu,\, \eta\pi\pi\nu,\,\ldots{}$) is discussed. It is shown, that the most general distribution can be characterized by 16 structure functions, most of which can be determined in currently ongoing high statistics experiments. Emphasis is put on $\tau$ decays in $e^{+}e^{-}$ experiments where the neutrino escapes detection and the $\tau$ rest frame cannot be reconstructed. The structure of the hadronic matrix elements, based on CVC and chiral lagrangians, is discussed.
[ { "created": "Wed, 31 Aug 1994 15:45:14 GMT", "version": "v1" } ]
2009-09-25
[ [ "K\"uhn", "J. H.", "" ], [ "Mirkes", "E.", "" ] ]
Semileptonic decays of polarized $\tau$ leptons are investigated. The most general angular distribution of three meson final states ($\tau\rightarrow \pi\pi\nu,\,K\pi\nu,\, \pi\pi\pi\nu,\\ \,K\pi\pi\nu,\, KK\pi\nu,\, KKK\nu,\, \eta\pi\pi\nu,\,\ldots{}$) is discussed. It is shown, that the most general distribution can be characterized by 16 structure functions, most of which can be determined in currently ongoing high statistics experiments. Emphasis is put on $\tau$ decays in $e^{+}e^{-}$ experiments where the neutrino escapes detection and the $\tau$ rest frame cannot be reconstructed. The structure of the hadronic matrix elements, based on CVC and chiral lagrangians, is discussed.
0706.0919
Zoltan Ligeti
Zoltan Ligeti
Mixing and CP violation in the D0 and Bs systems
Invited talk at the Flavor Physics and CP Violation Conference (FPCP 2007), Bled, Slovenia, 12-16 May 2007
ECONF C070512:021,2007
null
null
hep-ph
null
Recent developments for mixing and CP violation in the D0 and Bs systems are reviewed, including (i) the recently emerging evidence for D0-D0bar mixing and the interpretations of the measurements; (ii) the theoretical status of the calculations of Delta(Gamma_D) and Delta(m_D); (iii) some implications of the measurement of Bs mixing for new physics.
[ { "created": "Thu, 7 Jun 2007 18:35:11 GMT", "version": "v1" } ]
2011-03-23
[ [ "Ligeti", "Zoltan", "" ] ]
Recent developments for mixing and CP violation in the D0 and Bs systems are reviewed, including (i) the recently emerging evidence for D0-D0bar mixing and the interpretations of the measurements; (ii) the theoretical status of the calculations of Delta(Gamma_D) and Delta(m_D); (iii) some implications of the measurement of Bs mixing for new physics.
hep-ph/0208242
Levan Babukhadia
L. Babukhadia and M. D. Scadron
Nucleon strangeness and spin crisis?
Accepted for publication in special issue of Hadronic Journal
Hadronic J. 26 (2003) 503-513
null
null
hep-ph
null
We summarize three alternative extensions of the quark-valence picture of nucleon strangeness and spin, including (1) gluon spin in QCD, (2) Bjorken sum rule and QCD, (3) D--E meson mixing and tadpole leakage. All three approaches suggest that ~40% of the nucleon's spin (as well as its momentum) resides with quarks, but that less than 6% is due to strange quarks.
[ { "created": "Mon, 26 Aug 2002 23:14:16 GMT", "version": "v1" }, { "created": "Wed, 13 Nov 2002 22:35:32 GMT", "version": "v2" } ]
2007-05-23
[ [ "Babukhadia", "L.", "" ], [ "Scadron", "M. D.", "" ] ]
We summarize three alternative extensions of the quark-valence picture of nucleon strangeness and spin, including (1) gluon spin in QCD, (2) Bjorken sum rule and QCD, (3) D--E meson mixing and tadpole leakage. All three approaches suggest that ~40% of the nucleon's spin (as well as its momentum) resides with quarks, but that less than 6% is due to strange quarks.
2210.01733
Matteo Cerutti
Matteo Cerutti, Lorenzo Rossi, Simone Venturini, Alessandro Bacchetta, Valerio Bertone, Chiara Bissolotti and Marco Radici
Extraction of Pion Transverse Momentum Distributions from Drell-Yan data
null
null
10.1103/PhysRevD.107.014014
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We map the distribution of unpolarized quarks inside a unpolarized pion as a function of the quark's transverse momentum, encoded in unpolarized Transverse Momentum Distributions (TMDs). We extract the pion TMDs from available data of unpolarized pion-nucleus Drell-Yan processes, where the cross section is differential in the lepton-pair transverse momentum. In the cross section, pion TMDs are convoluted with nucleon TMDs that we consistently take from our previous studies. We obtain a fairly good agreement with data. We present also predictions for pion-nucleus scattering that is being measured by the COMPASS Collaboration.
[ { "created": "Tue, 4 Oct 2022 16:50:16 GMT", "version": "v1" } ]
2023-01-25
[ [ "Cerutti", "Matteo", "" ], [ "Rossi", "Lorenzo", "" ], [ "Venturini", "Simone", "" ], [ "Bacchetta", "Alessandro", "" ], [ "Bertone", "Valerio", "" ], [ "Bissolotti", "Chiara", "" ], [ "Radici", "Marco", "" ] ]
We map the distribution of unpolarized quarks inside a unpolarized pion as a function of the quark's transverse momentum, encoded in unpolarized Transverse Momentum Distributions (TMDs). We extract the pion TMDs from available data of unpolarized pion-nucleus Drell-Yan processes, where the cross section is differential in the lepton-pair transverse momentum. In the cross section, pion TMDs are convoluted with nucleon TMDs that we consistently take from our previous studies. We obtain a fairly good agreement with data. We present also predictions for pion-nucleus scattering that is being measured by the COMPASS Collaboration.
hep-ph/0504194
Ulrich Haisch
Martin Gorbahn, Ulrich Haisch and Mikolaj Misiak
Three-Loop Mixing of Dipole Operators
4 pages, 1 figure; journal version, text below Eq. (7) corrected
Phys.Rev.Lett.95:102004,2005
10.1103/PhysRevLett.95.102004
IPPP/05/15; DCPT/05/30; FERMILAB-Pub-05-076-T; IFT-9/2005
hep-ph
null
We calculate the complete three-loop O(alpha_s^3) anomalous dimension matrix for the dimension-five dipole operators that arise in the Standard Model after integrating out the top quark and the heavy electroweak bosons. Our computation completes the three-loop anomalous dimension matrix of operators that govern low-energy |Delta F| = 1 flavor-changing processes, and represents an important ingredient of the next-to-next-to-leading order QCD analysis of the Bbar -> X_s gamma decay.
[ { "created": "Thu, 21 Apr 2005 15:46:18 GMT", "version": "v1" }, { "created": "Mon, 15 Aug 2005 14:02:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Gorbahn", "Martin", "" ], [ "Haisch", "Ulrich", "" ], [ "Misiak", "Mikolaj", "" ] ]
We calculate the complete three-loop O(alpha_s^3) anomalous dimension matrix for the dimension-five dipole operators that arise in the Standard Model after integrating out the top quark and the heavy electroweak bosons. Our computation completes the three-loop anomalous dimension matrix of operators that govern low-energy |Delta F| = 1 flavor-changing processes, and represents an important ingredient of the next-to-next-to-leading order QCD analysis of the Bbar -> X_s gamma decay.
2001.10540
Thomas Hugle
Giorgio Arcadi, Giorgio Busoni, Thomas Hugle, Valentin Titus Tenorth
Comparing 2HDM $+$ Scalar and Pseudoscalar Simplified Models at LHC
26 pages, 14 figures
null
10.1007/JHEP06(2020)098
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we compare the current experimental LHC limits of the 2HDM $+$ scalar and pseudoscalar for the $t \bar{t}$, mono-$Z$ and mono-$h$ signatures and forecast the reach of future LHC upgrades for the mono-$Z$ channel. Furthermore, we comment on the possibility, in case of a signal detection, to discriminate between the two models. The 2HDM+S and 2HDM+PS are two notable examples of the so-called next generation of Dark Matter Simplified Models. They allow for a renormalizable coupling of fermionic, Standard Model singlet, Dark Matter with a two Higgs doublet sector, through the mixing of the latter with a scalar or pseudoscalar singlet.
[ { "created": "Tue, 28 Jan 2020 19:00:00 GMT", "version": "v1" }, { "created": "Fri, 19 Feb 2021 17:51:57 GMT", "version": "v2" } ]
2021-02-22
[ [ "Arcadi", "Giorgio", "" ], [ "Busoni", "Giorgio", "" ], [ "Hugle", "Thomas", "" ], [ "Tenorth", "Valentin Titus", "" ] ]
In this work we compare the current experimental LHC limits of the 2HDM $+$ scalar and pseudoscalar for the $t \bar{t}$, mono-$Z$ and mono-$h$ signatures and forecast the reach of future LHC upgrades for the mono-$Z$ channel. Furthermore, we comment on the possibility, in case of a signal detection, to discriminate between the two models. The 2HDM+S and 2HDM+PS are two notable examples of the so-called next generation of Dark Matter Simplified Models. They allow for a renormalizable coupling of fermionic, Standard Model singlet, Dark Matter with a two Higgs doublet sector, through the mixing of the latter with a scalar or pseudoscalar singlet.
hep-ph/9512262
Jianwei Qiu
Xiaofeng Guo and Jianwei Qiu
Nuclear Dependence in Direct Photon Production
24 pages text in RevTex, 9 Postscript figures
Phys.Rev.D53:6144-6155,1996
10.1103/PhysRevD.53.6144
null
hep-ph nucl-th
null
We calculate the nuclear dependence of direct photon production in hadron-nucleus collisions. In terms of a multiple scattering picture, we factorize the cross section for direct photon production into calculable short-distance partonic parts times multiparton correlation functions in nuclei. We present the hadron-nucleus cross section as $A^{\alpha}$ times the hadron-nucleon cross section. Using information on the multiparton correlation functions extracted from photon-nucleus experiments, we compute the value of $\alpha$ as a function of transverse momentum of the direct photon. We also compare our results with recent data from Fermilab experiment E706.
[ { "created": "Fri, 8 Dec 1995 23:02:52 GMT", "version": "v1" } ]
2014-11-17
[ [ "Guo", "Xiaofeng", "" ], [ "Qiu", "Jianwei", "" ] ]
We calculate the nuclear dependence of direct photon production in hadron-nucleus collisions. In terms of a multiple scattering picture, we factorize the cross section for direct photon production into calculable short-distance partonic parts times multiparton correlation functions in nuclei. We present the hadron-nucleus cross section as $A^{\alpha}$ times the hadron-nucleon cross section. Using information on the multiparton correlation functions extracted from photon-nucleus experiments, we compute the value of $\alpha$ as a function of transverse momentum of the direct photon. We also compare our results with recent data from Fermilab experiment E706.
1708.08464
Junwu Huang
Anson Hook and Junwu Huang
Probing axions with neutron star inspirals and other stellar processes
20 pages, 8 figures
null
10.1007/JHEP06(2018)036
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In certain models of a QCD axion, finite density corrections to the axion potential can result in the axion being sourced by large dense objects. There are a variety of ways to test this phenomenon, but perhaps the most surprising effect is that the axion can mediate forces between neutron stars that can be as strong as gravity. These forces can be attractive or repulsive and their presence can be detected by Advanced LIGO observations of neutron star inspirals. By a numerical coincidence, axion forces between neutron stars with gravitational strength naturally have an associated length scale of tens of kilometers or longer, similar to that of a neutron star. Future observations of neutron star mergers in Advanced LIGO can probe many orders of magnitude of axion parameter space. Because the axion is only sourced by large dense objects, the axion force evades fifth force constraints. We also outline several other ways to probe this phenomenon using electromagnetic signals associated with compact objects.
[ { "created": "Mon, 28 Aug 2017 18:00:08 GMT", "version": "v1" } ]
2018-07-04
[ [ "Hook", "Anson", "" ], [ "Huang", "Junwu", "" ] ]
In certain models of a QCD axion, finite density corrections to the axion potential can result in the axion being sourced by large dense objects. There are a variety of ways to test this phenomenon, but perhaps the most surprising effect is that the axion can mediate forces between neutron stars that can be as strong as gravity. These forces can be attractive or repulsive and their presence can be detected by Advanced LIGO observations of neutron star inspirals. By a numerical coincidence, axion forces between neutron stars with gravitational strength naturally have an associated length scale of tens of kilometers or longer, similar to that of a neutron star. Future observations of neutron star mergers in Advanced LIGO can probe many orders of magnitude of axion parameter space. Because the axion is only sourced by large dense objects, the axion force evades fifth force constraints. We also outline several other ways to probe this phenomenon using electromagnetic signals associated with compact objects.
hep-ph/0110408
Alexander Vereshagin
A.Vereshagin
Bootstrap equations for effective theories and the calculation of the $G_T/G_V$ ratio
4 pages, to be published in \pi N Newsletter 16 in The Proceedings of the MENU2001 Conference
PiN Newslett. 16 (2002) 426-428
null
null
hep-ph
null
A method is described for dealing with effective theories of hadron scattering. It allows one to reduce the number of independent renormalization prescriptions in those theories and gives a possibility to make numerical predictions. As an illustration, we show the results of comparison with the known data on $\pi\pi$, $\pi K$ and $\pi N$ elastic scattering. This work presents a generalization and the further development of our results first discussed at the MENU'99 Symposium
[ { "created": "Wed, 31 Oct 2001 15:05:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vereshagin", "A.", "" ] ]
A method is described for dealing with effective theories of hadron scattering. It allows one to reduce the number of independent renormalization prescriptions in those theories and gives a possibility to make numerical predictions. As an illustration, we show the results of comparison with the known data on $\pi\pi$, $\pi K$ and $\pi N$ elastic scattering. This work presents a generalization and the further development of our results first discussed at the MENU'99 Symposium
hep-ph/0105216
Edi Halyo
Edi Halyo
Hybrid Quintessence with an End or Quintessence from Branes and Large Dimensions
16 pages in phyzzx.tex, many minor corrections and additions, one reference added, typos corrected
JHEP 0110:025,2001
10.1088/1126-6708/2001/10/025
null
hep-ph astro-ph hep-th
null
We describe a model of hybrid quintessence in which in addition to the tracker field there is a trigger field which is responsible for ending quintessence. As a result, hybrid quintessence does not suffer from the problems associated with the eternal acceleration of the universe. We derive the hybrid quintessence potential on branes from the interbrane interaction in string theory and show that it requires TeV scale strings and two millimeter size dimensions. This scenario predicts a dark energy density of $O(mm^{-4})$ and relates the smallness of this energy to the large size of the extra dimensions.
[ { "created": "Mon, 21 May 2001 19:50:02 GMT", "version": "v1" }, { "created": "Thu, 24 May 2001 19:19:18 GMT", "version": "v2" }, { "created": "Thu, 14 Jun 2001 18:27:02 GMT", "version": "v3" } ]
2010-02-03
[ [ "Halyo", "Edi", "" ] ]
We describe a model of hybrid quintessence in which in addition to the tracker field there is a trigger field which is responsible for ending quintessence. As a result, hybrid quintessence does not suffer from the problems associated with the eternal acceleration of the universe. We derive the hybrid quintessence potential on branes from the interbrane interaction in string theory and show that it requires TeV scale strings and two millimeter size dimensions. This scenario predicts a dark energy density of $O(mm^{-4})$ and relates the smallness of this energy to the large size of the extra dimensions.
hep-ph/0404288
Petros Dimopoulos
P. Dimopoulos and K. Farakos
Layered Higgs Phase as a Possible Field Localisation on a Brane
1+15 pages, 12 figures
Phys.Rev. D70 (2004) 045005
10.1103/PhysRevD.70.045005
null
hep-ph hep-lat hep-th
null
So far it has been found by using lattice techniques that in the anisotropic five--dimensional Abelian Higgs model, a layered Higgs phase exists in addition to the expected five--dimensional one. The exploration of the phase diagram has shown that the two Higgs phases are separated by a phase transition from the confining phase. This transition is known to be first order. In this paper we explore the possibility of finding a second order transition point in the critical line which separates the first order phase transition from the crossover region. This is shown to be the case only for the four--dimensional Higgs layered phase whilst the phase transition to the five--dimensional broken phase remains first order. The layered phase serves as the possible realisation of four--dimensional spacetime dynamics which is embedded in a five--dimensional spacetime. These results are due to gauge and scalar field localisation by confining interactions along the extra fifth direction.
[ { "created": "Fri, 30 Apr 2004 14:45:25 GMT", "version": "v1" } ]
2009-11-10
[ [ "Dimopoulos", "P.", "" ], [ "Farakos", "K.", "" ] ]
So far it has been found by using lattice techniques that in the anisotropic five--dimensional Abelian Higgs model, a layered Higgs phase exists in addition to the expected five--dimensional one. The exploration of the phase diagram has shown that the two Higgs phases are separated by a phase transition from the confining phase. This transition is known to be first order. In this paper we explore the possibility of finding a second order transition point in the critical line which separates the first order phase transition from the crossover region. This is shown to be the case only for the four--dimensional Higgs layered phase whilst the phase transition to the five--dimensional broken phase remains first order. The layered phase serves as the possible realisation of four--dimensional spacetime dynamics which is embedded in a five--dimensional spacetime. These results are due to gauge and scalar field localisation by confining interactions along the extra fifth direction.