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hep-ph/0405072
Heather E. Logan
Heather E. Logan (Wisconsin)
The Littlest Higgs boson at a photon collider
34 pages, 7 figures; v2: refs added, errors fixed in Eqs. 18, 20, A2-A4, A12, A15, numerics updated, Sec.VI added with expanded discussion of uncertainties, conclusions unchanged; v3: refs added, minor changes to text, version to appear in PRD
Phys.Rev. D70 (2004) 115003
10.1103/PhysRevD.70.115003
MADPH-04-1378
hep-ph
null
We calculate the corrections to the partial widths of the light Higgs boson in the Littlest Higgs model due to effects of the TeV-scale physics. We focus on the loop-induced Higgs coupling to photon pairs, which is especially sensitive to the effects of new particles running in the loop. This coupling can be probed with high precision at a photon collider in the process gamma gamma -> H -> b bbar for a light Higgs boson with mass 115 GeV <= MH <~ 140 GeV. Using future LHC measurements of the parameters of the Littlest Higgs model, one can calculate a prediction for this process, which will serve as a test of the model and as a probe for a strongly-coupled UV completion at the 10 TeV scale. We outline the prospects for measuring these parameters with sufficient precision to match the expected experimental uncertainty on gamma gamma -> H -> b bbar.
[ { "created": "Sun, 9 May 2004 00:14:54 GMT", "version": "v1" }, { "created": "Mon, 26 Jul 2004 17:05:31 GMT", "version": "v2" }, { "created": "Thu, 4 Nov 2004 22:43:46 GMT", "version": "v3" } ]
2009-11-10
[ [ "Logan", "Heather E.", "", "Wisconsin" ] ]
We calculate the corrections to the partial widths of the light Higgs boson in the Littlest Higgs model due to effects of the TeV-scale physics. We focus on the loop-induced Higgs coupling to photon pairs, which is especially sensitive to the effects of new particles running in the loop. This coupling can be probed with high precision at a photon collider in the process gamma gamma -> H -> b bbar for a light Higgs boson with mass 115 GeV <= MH <~ 140 GeV. Using future LHC measurements of the parameters of the Littlest Higgs model, one can calculate a prediction for this process, which will serve as a test of the model and as a probe for a strongly-coupled UV completion at the 10 TeV scale. We outline the prospects for measuring these parameters with sufficient precision to match the expected experimental uncertainty on gamma gamma -> H -> b bbar.
1908.09796
Yilei Tang
Yi-Lei Tang
Structures of the Massive Vector Boson Propagators at Finite Temperature Illuminated by the Goldstone Equivalence Gauge
Typos corrected
JHEP10(2020)180
10.1007/JHEP10(2020)180
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the Goldstone equivalence gauge, we study the thermal corrections to an originally massive vector boson by checking the poles and branch cuts. We find that part of the Goldstone boson is spewed out from the longitudinal polarization, becoming a branch cut which can be approximated by the "quasi-poles" in the thermal environment. In this case, physical Goldstone boson somehow partly recovers. We also show the Feynmann rules for the "external legs" of these vector boson as well as the recovered Goldstone boson, expecting to simplify the vector boson participated process calculations by adopting the similar "tree-level" logic as in the zero temperature situation. Gauge boson mixing case are also discussed. Similar results are shown in other gauges, especially in the $R_\xi$ gauge.
[ { "created": "Mon, 26 Aug 2019 16:56:12 GMT", "version": "v1" }, { "created": "Mon, 2 Sep 2019 20:31:57 GMT", "version": "v2" }, { "created": "Fri, 25 Oct 2019 12:36:59 GMT", "version": "v3" }, { "created": "Mon, 13 Jan 2020 16:35:41 GMT", "version": "v4" }, { "created": "Mon, 25 May 2020 09:41:54 GMT", "version": "v5" }, { "created": "Fri, 30 Oct 2020 04:08:29 GMT", "version": "v6" } ]
2020-12-02
[ [ "Tang", "Yi-Lei", "" ] ]
Inspired by the Goldstone equivalence gauge, we study the thermal corrections to an originally massive vector boson by checking the poles and branch cuts. We find that part of the Goldstone boson is spewed out from the longitudinal polarization, becoming a branch cut which can be approximated by the "quasi-poles" in the thermal environment. In this case, physical Goldstone boson somehow partly recovers. We also show the Feynmann rules for the "external legs" of these vector boson as well as the recovered Goldstone boson, expecting to simplify the vector boson participated process calculations by adopting the similar "tree-level" logic as in the zero temperature situation. Gauge boson mixing case are also discussed. Similar results are shown in other gauges, especially in the $R_\xi$ gauge.
2303.04056
A. D. Polosa
Luciano Maiani, Antonio D. Polosa, Veronica Riquer
The Pentaquark Spectrum from Fermi Statistics
15 pages, 2 figures
null
10.1140/epjc/s10052-023-11492-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study compact hidden charm pentaquarks in the Born-Oppenheimer approximation, previously introduced for tetraquarks, assuming the heavy pair to be in a color octet. We show that Fermi statistics applied to the complex of the three light quarks, also in color octet, requires S-wave pentaquark ground states to consist of three octets of flavour-SU(3)_f, two with spin 1/2 and one with spin 3/2, in line with the observed, strangeness S=0,-1, spectrum. Additional lines corresponding to decays into J/\psi + Sigma and J/\psi + Xi are predicted. In the language of non-relativistic SU(6), ground state pentaquarks form either a 56 or a 20 representation, distinguished by presence or absence of pentaquarks decaying in the spin 3/2 decuplet, e.g. in J/\psi + Delta^++. Observation of a strangeness S=-2 or isospin I=3/2 pentaquarks would be a clear signature of compact, QCD bound pentaquarks.
[ { "created": "Tue, 7 Mar 2023 17:08:06 GMT", "version": "v1" } ]
2023-05-24
[ [ "Maiani", "Luciano", "" ], [ "Polosa", "Antonio D.", "" ], [ "Riquer", "Veronica", "" ] ]
We study compact hidden charm pentaquarks in the Born-Oppenheimer approximation, previously introduced for tetraquarks, assuming the heavy pair to be in a color octet. We show that Fermi statistics applied to the complex of the three light quarks, also in color octet, requires S-wave pentaquark ground states to consist of three octets of flavour-SU(3)_f, two with spin 1/2 and one with spin 3/2, in line with the observed, strangeness S=0,-1, spectrum. Additional lines corresponding to decays into J/\psi + Sigma and J/\psi + Xi are predicted. In the language of non-relativistic SU(6), ground state pentaquarks form either a 56 or a 20 representation, distinguished by presence or absence of pentaquarks decaying in the spin 3/2 decuplet, e.g. in J/\psi + Delta^++. Observation of a strangeness S=-2 or isospin I=3/2 pentaquarks would be a clear signature of compact, QCD bound pentaquarks.
1010.3946
Sebastian Philipp Schneider
Sebastian P. Schneider, Bastian Kubis, Christoph Ditsche
Rescattering effects in eta {\to} 3pi decays
48 pages, 5 figures; appendix C added, version published in JHEP
JHEP 1102:028,2011
10.1007/JHEP02(2011)028
HISKP-TH-10/26
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The isospin-breaking decay eta {\to} 3pi is an ideal tool to extract information on light quark mass ratios from experiment. For a precise determination, however, a detailed description of the Dalitz plot distribution is necessary. In that respect, in particular the slope parameter alpha of the neutral decay channel causes some concern, since the one-loop prediction from chiral perturbation theory misses the experimental value substantially. We use the modified non-relativistic effective field-theory, a dedicated framework to analyze final-state interactions beyond one loop including isospin-breaking corrections, to extract charged and neutral Dalitz plot parameters. Matching to chiral perturbation theory at next-to-leading order, we find alpha = -0.025 +- 0.005, in marginal agreement with experimental findings. We derive a relation between charged and neutral decay parameters that points towards a significant tension between the most recent KLOE measurements of these observables.
[ { "created": "Tue, 19 Oct 2010 15:12:34 GMT", "version": "v1" }, { "created": "Wed, 16 Feb 2011 15:10:06 GMT", "version": "v2" } ]
2011-02-17
[ [ "Schneider", "Sebastian P.", "" ], [ "Kubis", "Bastian", "" ], [ "Ditsche", "Christoph", "" ] ]
The isospin-breaking decay eta {\to} 3pi is an ideal tool to extract information on light quark mass ratios from experiment. For a precise determination, however, a detailed description of the Dalitz plot distribution is necessary. In that respect, in particular the slope parameter alpha of the neutral decay channel causes some concern, since the one-loop prediction from chiral perturbation theory misses the experimental value substantially. We use the modified non-relativistic effective field-theory, a dedicated framework to analyze final-state interactions beyond one loop including isospin-breaking corrections, to extract charged and neutral Dalitz plot parameters. Matching to chiral perturbation theory at next-to-leading order, we find alpha = -0.025 +- 0.005, in marginal agreement with experimental findings. We derive a relation between charged and neutral decay parameters that points towards a significant tension between the most recent KLOE measurements of these observables.
1504.02388
Jian Wang
Chong Sheng Li, Hai Tao Li, Ding Yu Shao and Jian Wang
Soft gluon resummation in the signal-background interference process of $gg(\to h^*) \to ZZ$
18 pages, 9 figures; v2 published in JHEP
JHEP08(2015)065
10.1007/JHEP08(2015)065
MITP/15-016
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a precise theoretical prediction for the signal-background interference process of $gg(\to h^*) \to ZZ$, which is useful to constrain the Higgs boson decay width and to measure Higgs couplings to the SM particles. The approximate NNLO $K$-factor is in the range of $2.05-2.45$ ($1.85-2.25$), depending on $M_{ZZ}$, at the 8 (13) TeV LHC. And the soft gluon resummation can increase the approximate NNLO result by about $10\%$ at both the 8 TeV and 13 TeV LHC. The theoretical uncertainties including the scale, uncalculated multi-loop amplitudes of the background and PDF$+\alpha_s$ are roughly $\mathcal{O}(10\%)$ at ${\rm NNLL'}$. We also confirm that the approximate $K$-factors in the interference and the pure signal processes are the same.
[ { "created": "Thu, 9 Apr 2015 16:59:52 GMT", "version": "v1" }, { "created": "Tue, 18 Aug 2015 17:33:27 GMT", "version": "v2" } ]
2015-08-19
[ [ "Li", "Chong Sheng", "" ], [ "Li", "Hai Tao", "" ], [ "Shao", "Ding Yu", "" ], [ "Wang", "Jian", "" ] ]
We present a precise theoretical prediction for the signal-background interference process of $gg(\to h^*) \to ZZ$, which is useful to constrain the Higgs boson decay width and to measure Higgs couplings to the SM particles. The approximate NNLO $K$-factor is in the range of $2.05-2.45$ ($1.85-2.25$), depending on $M_{ZZ}$, at the 8 (13) TeV LHC. And the soft gluon resummation can increase the approximate NNLO result by about $10\%$ at both the 8 TeV and 13 TeV LHC. The theoretical uncertainties including the scale, uncalculated multi-loop amplitudes of the background and PDF$+\alpha_s$ are roughly $\mathcal{O}(10\%)$ at ${\rm NNLL'}$. We also confirm that the approximate $K$-factors in the interference and the pure signal processes are the same.
1604.03285
Hoang Ngoc Long
T. T. Thuc, L. T. Hue, H. N. Long, T. Phong Nguyen
Lepton flavor violating decay of SM-like Higgs in a radiative neutrino mass model
25 pages, 7 figures, matches published version in PRD
Phys. Rev. D 93, 115026 (2016)
10.1103/PhysRevD.93.115026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The lepton flavor violating decay of the Standard Model-like Higgs (LFVHD) is discussed in the framework of the radiative neutrino mass model built in \cite{Kenji}. The branching ratio (BR) of the LFVHD are shown to reach $10^{-5}$ in the most interesting region of the parameter space shown in \cite{Kenji}. The dominant contributions come from the singly charged Higgs mediations, namely the coupling of $h^\pm_2$ with exotic neutrinos. Furthermore, if doubly charged Higgs is heavy enough to allow the mass of $h^\pm_2$ around 1 TeV, the mentioned BR can reach $10^{-4}$. Besides, we have obtained that the large values of the Br$(h\rightarrow\mu\tau)$ leads to very small ones of the Br$(h\rightarrow e\tau)$, much smaller than various sensitivity of current experiments.
[ { "created": "Tue, 12 Apr 2016 08:11:03 GMT", "version": "v1" }, { "created": "Mon, 20 Jun 2016 16:24:12 GMT", "version": "v2" } ]
2016-06-21
[ [ "Thuc", "T. T.", "" ], [ "Hue", "L. T.", "" ], [ "Long", "H. N.", "" ], [ "Nguyen", "T. Phong", "" ] ]
The lepton flavor violating decay of the Standard Model-like Higgs (LFVHD) is discussed in the framework of the radiative neutrino mass model built in \cite{Kenji}. The branching ratio (BR) of the LFVHD are shown to reach $10^{-5}$ in the most interesting region of the parameter space shown in \cite{Kenji}. The dominant contributions come from the singly charged Higgs mediations, namely the coupling of $h^\pm_2$ with exotic neutrinos. Furthermore, if doubly charged Higgs is heavy enough to allow the mass of $h^\pm_2$ around 1 TeV, the mentioned BR can reach $10^{-4}$. Besides, we have obtained that the large values of the Br$(h\rightarrow\mu\tau)$ leads to very small ones of the Br$(h\rightarrow e\tau)$, much smaller than various sensitivity of current experiments.
2402.19131
Xing-Xing Dong
Xing-Xing Dong, Shu-Min Zhao, Jia-Peng Huo, Tong-Tong Wang, Tai-Fu Feng
Charged Lepton Flavor Violation in the B-L symmetric SSM
to be published in Physical Review D
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged lepton flavor violation (CLFV) represents a clear new physics (NP) signal beyond the standard model (SM). In this work, we investigate CLFV processes $l_j^-\rightarrow l_i^- \gamma$ utilizing mass insertion approximation(MIA) in the minimal supersymmetric extension of the SM with local B-L gauge symmetry (B-LSSM). The MIA method can provide a set of simple analytic formulae for the form factors and the associated effective vertices, so that the movement of the CLFV decays $l_j^-\rightarrow l_i^- \gamma$ with the sensitive parameters will be intuitively analyzed. Considering the SM-like Higgs boson mass and the muon anomalous dipole moment (MDM) within $4\sigma$, $3\sigma$ and $2\sigma$ regions, we discuss the corresponding constraints on the relevant parameter space of the model.
[ { "created": "Thu, 29 Feb 2024 13:07:01 GMT", "version": "v1" } ]
2024-03-01
[ [ "Dong", "Xing-Xing", "" ], [ "Zhao", "Shu-Min", "" ], [ "Huo", "Jia-Peng", "" ], [ "Wang", "Tong-Tong", "" ], [ "Feng", "Tai-Fu", "" ] ]
Charged lepton flavor violation (CLFV) represents a clear new physics (NP) signal beyond the standard model (SM). In this work, we investigate CLFV processes $l_j^-\rightarrow l_i^- \gamma$ utilizing mass insertion approximation(MIA) in the minimal supersymmetric extension of the SM with local B-L gauge symmetry (B-LSSM). The MIA method can provide a set of simple analytic formulae for the form factors and the associated effective vertices, so that the movement of the CLFV decays $l_j^-\rightarrow l_i^- \gamma$ with the sensitive parameters will be intuitively analyzed. Considering the SM-like Higgs boson mass and the muon anomalous dipole moment (MDM) within $4\sigma$, $3\sigma$ and $2\sigma$ regions, we discuss the corresponding constraints on the relevant parameter space of the model.
hep-ph/0603256
Bernd-Jochen Schaefer
Bernd-Jochen Schaefer, Jochen Wambach
Susceptibilities near the QCD (tri)critical point
14 pages, 19 figures; v3 typos and minor changes, references added
Phys.Rev.D75:085015,2007
10.1103/PhysRevD.75.085015
null
hep-ph hep-th nucl-th
null
Based on the proper-time renormalization group approach, the scalar and the quark number susceptibilities in the vicinity of possible critical end points of the hadronic phase diagram are investigated in the two-flavor quark-meson model. After discussing the quark-mass dependence of the location of such points, the critical behavior of the in-medium meson masses and quark number density are calculated. The universality classes of the end points are determined by calculating the critical exponents of the susceptibilities. In order to numerically estimate the influence of fluctuations we compare all quantities with results from a mean-field approximation. It is concluded that the region in the phase diagram where the susceptibilities are enhanced is more compressed around the critical end point if fluctuations are included.
[ { "created": "Thu, 30 Mar 2006 14:01:47 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2006 15:20:14 GMT", "version": "v2" }, { "created": "Fri, 7 Jul 2006 14:25:50 GMT", "version": "v3" } ]
2008-11-26
[ [ "Schaefer", "Bernd-Jochen", "" ], [ "Wambach", "Jochen", "" ] ]
Based on the proper-time renormalization group approach, the scalar and the quark number susceptibilities in the vicinity of possible critical end points of the hadronic phase diagram are investigated in the two-flavor quark-meson model. After discussing the quark-mass dependence of the location of such points, the critical behavior of the in-medium meson masses and quark number density are calculated. The universality classes of the end points are determined by calculating the critical exponents of the susceptibilities. In order to numerically estimate the influence of fluctuations we compare all quantities with results from a mean-field approximation. It is concluded that the region in the phase diagram where the susceptibilities are enhanced is more compressed around the critical end point if fluctuations are included.
0708.1553
Huanjun Zhang
Guoli Liu, Huanjun Zhang
Single top production associated with a neutral scalar at LHC in topcolor-assisted technicolor
7 pages, 3 figs
null
10.1088/1674-1137/32/9/004
null
hep-ph
null
The topcolor-assisted technicolor (TC2) model predicts a number of neutral scalars like the top-pion ($\pi^0_t$) and the top-Higgs ($h^0_t$). These scalars have flavor-changing neutral-current (FCNC) top quark couplings, among which the top-charm transition couplings may be sizable. Such FCNC couplings induce single top productions associated with a neutral scalar at the CERN Large Hadron Collider (LHC) through the parton processes $cg \to t \pi_t^0$ and $cg \to t h_t^0$. In this note we examine these productions and find their production rates can exceed the $3\sigma$ sensitivity of the LHC in a large part of parameter space. Since in the Standard Model and the minimal supersymmetric model such rare productions have unobservably small production rates at the LHC, these rare processes will serve as a good probe for the TC2 model.
[ { "created": "Sat, 11 Aug 2007 09:14:31 GMT", "version": "v1" } ]
2015-05-13
[ [ "Liu", "Guoli", "" ], [ "Zhang", "Huanjun", "" ] ]
The topcolor-assisted technicolor (TC2) model predicts a number of neutral scalars like the top-pion ($\pi^0_t$) and the top-Higgs ($h^0_t$). These scalars have flavor-changing neutral-current (FCNC) top quark couplings, among which the top-charm transition couplings may be sizable. Such FCNC couplings induce single top productions associated with a neutral scalar at the CERN Large Hadron Collider (LHC) through the parton processes $cg \to t \pi_t^0$ and $cg \to t h_t^0$. In this note we examine these productions and find their production rates can exceed the $3\sigma$ sensitivity of the LHC in a large part of parameter space. Since in the Standard Model and the minimal supersymmetric model such rare productions have unobservably small production rates at the LHC, these rare processes will serve as a good probe for the TC2 model.
hep-ph/9403318
null
Nick Evans
Strong Extended Technicolour Interactions and the $Zb\bar{b}$ Vertex
9 pages + 3 appended ps figures, SWAT/27
Phys.Lett. B331 (1994) 378-382
10.1016/0370-2693(94)91067-7
null
hep-ph
null
LEP precision measurements of the $Zb\bar{b}$ vertex coupling are sufficiently accurate to see the non-oblique corrections from the heavy gauge boson responsible for the large top mass in standard extended tecnicolour models. If the ETC couplings are strong the techni-fermion condensate may be enhanced by several orders of magnitude allowing a top mass of order 150GeV to be obtained for large values of the ETC breaking scale sufficient to supress the ETC contribution to the $Zb{\bar b}$ vertex. In this letter we investigate the degree of fine tuning of the ETC coupling required in a realistic model. We conclude that the fine tuning need only be of order $10\%$.
[ { "created": "Mon, 21 Mar 1994 13:18:54 GMT", "version": "v1" } ]
2009-10-28
[ [ "Evans", "Nick", "" ] ]
LEP precision measurements of the $Zb\bar{b}$ vertex coupling are sufficiently accurate to see the non-oblique corrections from the heavy gauge boson responsible for the large top mass in standard extended tecnicolour models. If the ETC couplings are strong the techni-fermion condensate may be enhanced by several orders of magnitude allowing a top mass of order 150GeV to be obtained for large values of the ETC breaking scale sufficient to supress the ETC contribution to the $Zb{\bar b}$ vertex. In this letter we investigate the degree of fine tuning of the ETC coupling required in a realistic model. We conclude that the fine tuning need only be of order $10\%$.
1105.3434
Martin Wiebusch
Patrick Gonz\'alez, J\"urgen Rohrwild, Martin Wiebusch
Electroweak Precision Observables within a Fourth Generation Model with General Flavour Structure
null
Eur. Phys. J. C (2012) 72:2007
10.1140/epjc/s10052-012-2007-0
TTP11-15
hep-ph
http://creativecommons.org/licenses/by-nc-sa/3.0/
We calculate the contributions to electroweak precision observables (EWPOs) due to a fourth generation of fermions with the most general (quark-)flavour structure (but assuming Dirac neutrinos and a trivial flavour structure in the lepton sector). The new-physics contributions to the EWPOs are calculated at one-loop order using automated tools (FeynArts/FormCalc). No further approximations are made in our calculation. We discuss the size of non-oblique contributions arising from Z--quark--anti-quark vertex corrections and the dependence of the EWPOs on all CKM mixing angles involving the fourth generation. We find that the electroweak precision observables are sensitive to two of the fourth-generation mixing angles and that the corresponding constraints on these angles are competitive with those obtained from flavour physics. For non-trivial 4x4 flavour structures, the non-oblique contributions lead to relative corrections of several permille and should be included in a global fit.
[ { "created": "Tue, 17 May 2011 16:58:51 GMT", "version": "v1" }, { "created": "Thu, 3 May 2012 17:18:41 GMT", "version": "v2" } ]
2012-06-20
[ [ "González", "Patrick", "" ], [ "Rohrwild", "Jürgen", "" ], [ "Wiebusch", "Martin", "" ] ]
We calculate the contributions to electroweak precision observables (EWPOs) due to a fourth generation of fermions with the most general (quark-)flavour structure (but assuming Dirac neutrinos and a trivial flavour structure in the lepton sector). The new-physics contributions to the EWPOs are calculated at one-loop order using automated tools (FeynArts/FormCalc). No further approximations are made in our calculation. We discuss the size of non-oblique contributions arising from Z--quark--anti-quark vertex corrections and the dependence of the EWPOs on all CKM mixing angles involving the fourth generation. We find that the electroweak precision observables are sensitive to two of the fourth-generation mixing angles and that the corresponding constraints on these angles are competitive with those obtained from flavour physics. For non-trivial 4x4 flavour structures, the non-oblique contributions lead to relative corrections of several permille and should be included in a global fit.
hep-ph/0403292
Luc Marleau
L. Marleau (U. Laval)
Solving Skyrmions
16 pages (LATEX), jhep.cls, no figure
null
null
LAVAL-PHY-04-11
hep-ph
null
We find exact solutions for Skyrmions for the Skyrme-like models. Constructing first the recursion formulae at small and large distance behavior, we proceed by implementing these constraints to a chosen parametrization of the solutions. The procedure is applied to the spherically symmetric hedgehog solution and to topological number N > 1 solutions based on rational maps.
[ { "created": "Tue, 30 Mar 2004 18:16:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Marleau", "L.", "", "U. Laval" ] ]
We find exact solutions for Skyrmions for the Skyrme-like models. Constructing first the recursion formulae at small and large distance behavior, we proceed by implementing these constraints to a chosen parametrization of the solutions. The procedure is applied to the spherically symmetric hedgehog solution and to topological number N > 1 solutions based on rational maps.
2202.04608
Ian Banta
Ian Banta
A Strongly First-Order Electroweak Phase Transition from Loryons
21 pages, 2 figures. Matches published version. Updates to sections 2 and 3.2 and miscellaneous minor changes relative to v1
JHEP 06 (2022), 099
10.1007/JHEP06(2022)099
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the effect of BSM particles receiving most of their mass from their coupling to the Higgs boson ("Loryons") on the electroweak phase transition. The existence of BSM Loryons would imply that electroweak symmetry must be non-linearly realized in the effective theory of the Standard Model. Since, by definition, Loryons have a significant coupling to the Higgs, they are expected to have a significant effect on the Higgs effective potential and thereby the electroweak phase transition. We show that the BSM Loryon parameter space viable under current experimental and theoretical constraints overlaps heavily with the parameter space in which a strongly first-order phase transition is predicted. The portion of the experimentally allowed parameter space which gives a strongly first-order phase transition is significantly larger for Loryons as compared to non-Loryons.
[ { "created": "Wed, 9 Feb 2022 18:03:53 GMT", "version": "v1" }, { "created": "Wed, 10 Aug 2022 15:34:05 GMT", "version": "v2" } ]
2022-08-11
[ [ "Banta", "Ian", "" ] ]
We study the effect of BSM particles receiving most of their mass from their coupling to the Higgs boson ("Loryons") on the electroweak phase transition. The existence of BSM Loryons would imply that electroweak symmetry must be non-linearly realized in the effective theory of the Standard Model. Since, by definition, Loryons have a significant coupling to the Higgs, they are expected to have a significant effect on the Higgs effective potential and thereby the electroweak phase transition. We show that the BSM Loryon parameter space viable under current experimental and theoretical constraints overlaps heavily with the parameter space in which a strongly first-order phase transition is predicted. The portion of the experimentally allowed parameter space which gives a strongly first-order phase transition is significantly larger for Loryons as compared to non-Loryons.
1005.4930
Pavel Fileviez Perez
Pavel Fileviez Perez, Sogee Spinner
The Fate of R-Parity
null
Phys.Rev.D83:035004,2011
10.1103/PhysRevD.83.035004
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possible origin of the R-parity violating interactions in the minimal supersymmetric standard model and its connection to the radiative symmetry breaking mechanism (RSBM) is investigated. In the context of the simplest model where the implementation of the RSBM is possible, we find that in the majority of the parameter space R-parity is spontaneously broken at the low-scale. These results hint at the possibility that R-parity violating processes will be observed at the Large Hadron Collider, if Supersymmetry is realized in nature.
[ { "created": "Wed, 26 May 2010 20:00:17 GMT", "version": "v1" } ]
2011-02-18
[ [ "Perez", "Pavel Fileviez", "" ], [ "Spinner", "Sogee", "" ] ]
The possible origin of the R-parity violating interactions in the minimal supersymmetric standard model and its connection to the radiative symmetry breaking mechanism (RSBM) is investigated. In the context of the simplest model where the implementation of the RSBM is possible, we find that in the majority of the parameter space R-parity is spontaneously broken at the low-scale. These results hint at the possibility that R-parity violating processes will be observed at the Large Hadron Collider, if Supersymmetry is realized in nature.
1704.03878
Jesse Thaler
Philippe Gras, Stefan H\"oche, Deepak Kar, Andrew Larkoski, Leif L\"onnblad, Simon Pl\"atzer, Andrzej Si\'odmok, Peter Skands, Gregory Soyez, Jesse Thaler
Systematics of quark/gluon tagging
50 pages, 20 figures, extended version of the Les Houches 2015 study from arXiv:1605.04692; v2: updated to approximately match journal version, including improved discussion of nonperturbative Casimir scaling and more umlauts
JHEP 1707 (2017) 091
10.1007/JHEP07(2017)091
MIT-CTP 4885, CoEPP-MN-17-2, MCNET-17-04
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By measuring the substructure of a jet, one can assign it a "quark" or "gluon" tag. In the eikonal (double-logarithmic) limit, quark/gluon discrimination is determined solely by the color factor of the initiating parton (C_F versus C_A). In this paper, we confront the challenges faced when going beyond this leading-order understanding, using both parton-shower generators and first-principles calculations to assess the impact of higher-order perturbative and nonperturbative physics. Working in the idealized context of electron-positron collisions, where one can define a proxy for quark and gluon jets based on the Lorentz structure of the production vertex, we find a fascinating interplay between perturbative shower effects and nonperturbative hadronization effects. Turning to proton-proton collisions, we highlight a core set of measurements that would constrain current uncertainties in quark/gluon tagging and improve the overall modeling of jets at the Large Hadron Collider.
[ { "created": "Wed, 12 Apr 2017 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 8 Aug 2017 13:50:15 GMT", "version": "v2" } ]
2017-08-09
[ [ "Gras", "Philippe", "" ], [ "Höche", "Stefan", "" ], [ "Kar", "Deepak", "" ], [ "Larkoski", "Andrew", "" ], [ "Lönnblad", "Leif", "" ], [ "Plätzer", "Simon", "" ], [ "Siódmok", "Andrzej", "" ], [ "Skands", "Peter", "" ], [ "Soyez", "Gregory", "" ], [ "Thaler", "Jesse", "" ] ]
By measuring the substructure of a jet, one can assign it a "quark" or "gluon" tag. In the eikonal (double-logarithmic) limit, quark/gluon discrimination is determined solely by the color factor of the initiating parton (C_F versus C_A). In this paper, we confront the challenges faced when going beyond this leading-order understanding, using both parton-shower generators and first-principles calculations to assess the impact of higher-order perturbative and nonperturbative physics. Working in the idealized context of electron-positron collisions, where one can define a proxy for quark and gluon jets based on the Lorentz structure of the production vertex, we find a fascinating interplay between perturbative shower effects and nonperturbative hadronization effects. Turning to proton-proton collisions, we highlight a core set of measurements that would constrain current uncertainties in quark/gluon tagging and improve the overall modeling of jets at the Large Hadron Collider.
hep-ph/9211228
My Account
J. Lopez, D. Nanopoulos, H. Pois, and A. Zichichi
Proposed Tests for Minimal SU(5) Supergravity at Fermilab, Gran Sasso, SuperKamiokande, and LEP
10 pages plus two figures (included as postscript files); CTP-TAMU-72/92, CERN-TH.6716/92
Phys.Lett.B299:262-266,1993
10.1016/0370-2693(93)90257-I
null
hep-ph
null
A series of predictions are worked out in order to put the minimal $SU(5)$ supergravity model under experimental test. Using the two-loop gauge coupling renormalization group equations, with the inclusion of supersymmetric threshold corrections, we calculate a new value for the proton decay rate in this model and find that SuperKamiokande and Gran Sasso should see the proton decay mode $p\to\bar\nu K^+$ for most of the allowed parameter space. A set of physically sensible assumptions and the cosmological requirement of a not too young Universe give us a rather restrictive set of allowed points in the parameter space, which characterizes this model. This set implies the existence of interesting correlations among various masses: either the lightest chargino and the next-to-lightest neutralino are below $\approx100\GeV$ (and therefore observable at the Tevatron) or the lightest Higgs boson is below $\approx50\GeV$ (and therefore observable at LEP I-II). These tests are crucial steps towards selecting the correct low-energy effective supergravity model. We also comment on the compatibility of the model with $\sin^2\theta_w(M_Z)$ measurements as a function of $\alpha_3(M_Z)$.
[ { "created": "Sun, 8 Nov 1992 01:22:35 GMT", "version": "v1" } ]
2009-08-25
[ [ "Lopez", "J.", "" ], [ "Nanopoulos", "D.", "" ], [ "Pois", "H.", "" ], [ "Zichichi", "A.", "" ] ]
A series of predictions are worked out in order to put the minimal $SU(5)$ supergravity model under experimental test. Using the two-loop gauge coupling renormalization group equations, with the inclusion of supersymmetric threshold corrections, we calculate a new value for the proton decay rate in this model and find that SuperKamiokande and Gran Sasso should see the proton decay mode $p\to\bar\nu K^+$ for most of the allowed parameter space. A set of physically sensible assumptions and the cosmological requirement of a not too young Universe give us a rather restrictive set of allowed points in the parameter space, which characterizes this model. This set implies the existence of interesting correlations among various masses: either the lightest chargino and the next-to-lightest neutralino are below $\approx100\GeV$ (and therefore observable at the Tevatron) or the lightest Higgs boson is below $\approx50\GeV$ (and therefore observable at LEP I-II). These tests are crucial steps towards selecting the correct low-energy effective supergravity model. We also comment on the compatibility of the model with $\sin^2\theta_w(M_Z)$ measurements as a function of $\alpha_3(M_Z)$.
hep-ph/9403260
Evan Reidell
Xiangdong Ji
$Q^2$-Dependence of Deep Inelastic Sum Rules
8 pages in plain TeX with PostScript figures to follow, MIT-CTP-2288
null
null
null
hep-ph
null
In this talk, I will concentrate on $Q^2$-dependence of deep inelastic sum rules. I will first give a modern definition of deep-inelastic sum rules and then discuss physical origins of their scaling violation at finite $Q^2$. Following this, I discuss a few well-known examples, in particular, the Bjorken sum rule, which is at the center of interest of this symposium. Finally, I consider the $Q^2 \to 0$ limit of sum rules using low-energy theorems. I think this can motivate some interesting CEBAF physics.
[ { "created": "Wed, 9 Mar 1994 22:58:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ji", "Xiangdong", "" ] ]
In this talk, I will concentrate on $Q^2$-dependence of deep inelastic sum rules. I will first give a modern definition of deep-inelastic sum rules and then discuss physical origins of their scaling violation at finite $Q^2$. Following this, I discuss a few well-known examples, in particular, the Bjorken sum rule, which is at the center of interest of this symposium. Finally, I consider the $Q^2 \to 0$ limit of sum rules using low-energy theorems. I think this can motivate some interesting CEBAF physics.
1502.03008
Lu\'is Lavoura
L. Lavoura
New texture-zero models for lepton mixing
22 pages
null
null
CFTP/15-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I systematically consider, in the context of the type-I see-saw mechanism, all the predictive cases in which both the Dirac mass matrix connecting the left-handed neutrinos to the right-handed neutrinos, and the Majorana mass matrix of the latter neutrinos, feature texture zeros, while the mass matrix of the charged leptons is diagonal. I have found a few cases which had not been discussed in the literature previously.
[ { "created": "Tue, 10 Feb 2015 17:41:13 GMT", "version": "v1" } ]
2015-02-11
[ [ "Lavoura", "L.", "" ] ]
I systematically consider, in the context of the type-I see-saw mechanism, all the predictive cases in which both the Dirac mass matrix connecting the left-handed neutrinos to the right-handed neutrinos, and the Majorana mass matrix of the latter neutrinos, feature texture zeros, while the mass matrix of the charged leptons is diagonal. I have found a few cases which had not been discussed in the literature previously.
hep-ph/0411133
Ryuichiro Kitano
Ryuichiro Kitano and Ian Low
Dark Matter from Baryon Asymmetry
12 pages; v2: bounds on the mass of the messenger particle are relaxed; conclusions unchanged. additional minor modifications
Phys.Rev. D71 (2005) 023510
10.1103/PhysRevD.71.023510
null
hep-ph astro-ph
null
The measured densities of dark and baryonic matter are surprisingly close to each other, even though the baryon asymmetry and the dark matter are usually explained by unrelated mechanisms. We consider a scenario where the dark matter S is produced non-thermally from the decay of a messenger particle X, which carries the baryon number and compensates for the baryon asymmetry in the Universe, thereby establishing a connection between the baryonic and dark matter densities. We propose a simple model to realize this scenario, adding only a light singlet fermion S and a colored particle X which has a mass in the O(TeV) range and a lifetime to appear long-lived in collider detector. Therefore in hadron colliders the signal is similar to that of a stable or long-lived gluino in supersymmetric models.
[ { "created": "Tue, 9 Nov 2004 21:49:42 GMT", "version": "v1" }, { "created": "Mon, 3 Jan 2005 16:27:04 GMT", "version": "v2" } ]
2009-11-10
[ [ "Kitano", "Ryuichiro", "" ], [ "Low", "Ian", "" ] ]
The measured densities of dark and baryonic matter are surprisingly close to each other, even though the baryon asymmetry and the dark matter are usually explained by unrelated mechanisms. We consider a scenario where the dark matter S is produced non-thermally from the decay of a messenger particle X, which carries the baryon number and compensates for the baryon asymmetry in the Universe, thereby establishing a connection between the baryonic and dark matter densities. We propose a simple model to realize this scenario, adding only a light singlet fermion S and a colored particle X which has a mass in the O(TeV) range and a lifetime to appear long-lived in collider detector. Therefore in hadron colliders the signal is similar to that of a stable or long-lived gluino in supersymmetric models.
hep-ph/9608413
null
Sean Fleming (University of Wisconsin, Madison), Oscar F. Hernandez (Universite de Montreal), Ivan Maksymyk (University of Texas, Austin), Helene Nadeau (McGill University, Montreal)
NRQCD matrix elements in polarization of J-Psi produced from b-decay
9 pages, Revtex, 2 figures
Phys.Rev. D55 (1997) 4098-4104
10.1103/PhysRevD.55.4098
MADPH-96-953, UTTG-11-96,McGill-96-26,UdeM-GPP-TH-96-40
hep-ph hep-ex
null
We present the non-relativistic QCD (NRQCD) prediction for the polarization of the J-Psi produced in b to J-Psi + X, as well as the helicity-summed production rate. We propose that these observables provide a means of measuring the three most important color-octet NRQCD matrix elements involved in J-Psi production. Anticipating the measurement of the polarization parameter alpha, we determine its expected range given current experimental bounds on the color-octet matrix elements.
[ { "created": "Thu, 22 Aug 1996 15:44:46 GMT", "version": "v1" } ]
2009-10-28
[ [ "Fleming", "Sean", "", "University of Wisconsin, Madison" ], [ "Hernandez", "Oscar F.", "", "Universite de Montreal" ], [ "Maksymyk", "Ivan", "", "University of Texas, Austin" ], [ "Nadeau", "Helene", "", "McGill University, Montreal" ] ]
We present the non-relativistic QCD (NRQCD) prediction for the polarization of the J-Psi produced in b to J-Psi + X, as well as the helicity-summed production rate. We propose that these observables provide a means of measuring the three most important color-octet NRQCD matrix elements involved in J-Psi production. Anticipating the measurement of the polarization parameter alpha, we determine its expected range given current experimental bounds on the color-octet matrix elements.
1206.4191
Jacques Soffer
Claude Bourrely, Franco Buccella and Jacques Soffer
The statistical model for parton distributions
7 pages, 3 figures, Invited talk at XX International Workshop on "`Deep-Inelastic Scattering and related subjects"', University of Bonn, Germany, March 26-30 2012, presented by F. Buccella, to appear in the conference proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The phenomenological motivations, the expressions and the comparison with experiment of the parton distributions inspired by the quantum statistics are described. The Fermi-Dirac expressions for the quarks and their antiparticles automatically account for the correlation between the shape and the first moments of the valence partons, as well as the flavor and spin asymmetries of the sea. One is able to describe with a small number of parameters both unpolarized and polarized structure functions.
[ { "created": "Tue, 19 Jun 2012 12:31:52 GMT", "version": "v1" } ]
2012-06-20
[ [ "Bourrely", "Claude", "" ], [ "Buccella", "Franco", "" ], [ "Soffer", "Jacques", "" ] ]
The phenomenological motivations, the expressions and the comparison with experiment of the parton distributions inspired by the quantum statistics are described. The Fermi-Dirac expressions for the quarks and their antiparticles automatically account for the correlation between the shape and the first moments of the valence partons, as well as the flavor and spin asymmetries of the sea. One is able to describe with a small number of parameters both unpolarized and polarized structure functions.
2103.12123
Howard Baer
Howard Baer, Vernon Barger, Shadman Salam and Hasan Serce
Sparticle and Higgs boson masses from the landscape: dynamical versus spontaneous supersymmetry breaking
14 pages, 11 .png figures
null
10.1103/PhysRevD.104.115025
OU-HEP-210322
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Perturbative supersymmetry breaking on the landscape of string vacua is expected to favor large soft terms as a power-law or log distribution, but tempered by an anthropic veto of inappropriate vacua or vacua leading to too large a value for the derived weak scale -- a violation of the atomic principle. Indeed, scans of such vacua yield a statistical prediction for light Higgs boson mass m_h~ 125 GeV with sparticles (save possibly light higgsinos) typically beyond LHC reach. In contrast, models of dynamical SUSY breaking (DSB) -- with a hidden sector gauge coupling g^2 scanned uniformly -- lead to gaugino condensation and a uniform distribution of soft parameters on a log scale. Then soft terms are expected to be distributed as $m_{\rm soft}^{-1}$ favoring small values. A scan of DSB soft terms generally leads to $m_h\ll 125$ GeV and sparticle masses usually below LHC limits. Thus, the DSB landscape scenario seems excluded from LHC search results. An alternative is that the exponential suppression of the weak scale is set anthropically on the landscape via the atomic principle.
[ { "created": "Mon, 22 Mar 2021 18:29:05 GMT", "version": "v1" } ]
2022-01-05
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Salam", "Shadman", "" ], [ "Serce", "Hasan", "" ] ]
Perturbative supersymmetry breaking on the landscape of string vacua is expected to favor large soft terms as a power-law or log distribution, but tempered by an anthropic veto of inappropriate vacua or vacua leading to too large a value for the derived weak scale -- a violation of the atomic principle. Indeed, scans of such vacua yield a statistical prediction for light Higgs boson mass m_h~ 125 GeV with sparticles (save possibly light higgsinos) typically beyond LHC reach. In contrast, models of dynamical SUSY breaking (DSB) -- with a hidden sector gauge coupling g^2 scanned uniformly -- lead to gaugino condensation and a uniform distribution of soft parameters on a log scale. Then soft terms are expected to be distributed as $m_{\rm soft}^{-1}$ favoring small values. A scan of DSB soft terms generally leads to $m_h\ll 125$ GeV and sparticle masses usually below LHC limits. Thus, the DSB landscape scenario seems excluded from LHC search results. An alternative is that the exponential suppression of the weak scale is set anthropically on the landscape via the atomic principle.
1401.5443
Li Cheng
Li Cheng, Alper Hayreter and German Valencia
Top-quark forward-backward asymmetry from a color-octet t-channel resonance
References added and corrected, typos fixed
Phys. Rev. D 89, 095009 (2014)
10.1103/PhysRevD.89.095009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider new physics contributions to the top-quark forward-backward asymmetry from a neutral $V^0_8$ or charged $V^+_8$ color-octet vector exchanged in the $t$-channel. We study the phenomenological constraints on these particles arising from the Tevatron and LHC7 measurements and compare them with those on their color singlet counterparts $Z^\prime$ and $W^\prime$. We find that the color octets fare better than the singlets in that they generate a lower $A_C$, a lower high-invariant mass cross-section at LHC7 and a lower same sign top-pair cross-section. However, they also generate a lower $A_{FB}$ than their color-singlet counterparts.
[ { "created": "Tue, 21 Jan 2014 20:09:00 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2014 21:06:47 GMT", "version": "v2" } ]
2015-07-10
[ [ "Cheng", "Li", "" ], [ "Hayreter", "Alper", "" ], [ "Valencia", "German", "" ] ]
We consider new physics contributions to the top-quark forward-backward asymmetry from a neutral $V^0_8$ or charged $V^+_8$ color-octet vector exchanged in the $t$-channel. We study the phenomenological constraints on these particles arising from the Tevatron and LHC7 measurements and compare them with those on their color singlet counterparts $Z^\prime$ and $W^\prime$. We find that the color octets fare better than the singlets in that they generate a lower $A_C$, a lower high-invariant mass cross-section at LHC7 and a lower same sign top-pair cross-section. However, they also generate a lower $A_{FB}$ than their color-singlet counterparts.
2203.13786
Wei-Hong Liang
Jia-Ting Li, Jia-Xin Lin, Gong-Jie Zhang, Wei-Hong Liang and E. Oset
The $\bar B_s^0 \to J/\psi \pi^0 \eta$ decay and the $a_0(980)-f_0(980)$ mixing
12 pages, 4 figures; v2: version published in Chin. Phys. C
null
10.1088/1674-1137/ac6cd5
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the $\bar B_s^0 \to J/\psi f_0(980)$ and $\bar B_s^0 \to J/\psi a_0(980)$ reactions, and pay attention to the different sources of isospin violation and mixing of $f_0(980)$ and $a_0(980)$ resonances where these resonances are dynamically generated from meson-meson interaction. We find that the main cause of isospin violation is the isospin breaking in the meson-meson transition $T$ matrices, and the other source is that the loops involving kaons in the production mechanism do not cancel due to the different masses of the charged and neutral kaons. We obtain a branching ratio for $a_0(980)$ production of the order of $5 \times 10^{-6}$. Future experiments can address this problem, and the production rate and shape of the $\pi^0 \eta$ mass distribution will definitely help to better understand the nature of scalar resonances.
[ { "created": "Fri, 25 Mar 2022 17:11:27 GMT", "version": "v1" }, { "created": "Mon, 30 Oct 2023 12:26:35 GMT", "version": "v2" } ]
2023-10-31
[ [ "Li", "Jia-Ting", "" ], [ "Lin", "Jia-Xin", "" ], [ "Zhang", "Gong-Jie", "" ], [ "Liang", "Wei-Hong", "" ], [ "Oset", "E.", "" ] ]
We study the $\bar B_s^0 \to J/\psi f_0(980)$ and $\bar B_s^0 \to J/\psi a_0(980)$ reactions, and pay attention to the different sources of isospin violation and mixing of $f_0(980)$ and $a_0(980)$ resonances where these resonances are dynamically generated from meson-meson interaction. We find that the main cause of isospin violation is the isospin breaking in the meson-meson transition $T$ matrices, and the other source is that the loops involving kaons in the production mechanism do not cancel due to the different masses of the charged and neutral kaons. We obtain a branching ratio for $a_0(980)$ production of the order of $5 \times 10^{-6}$. Future experiments can address this problem, and the production rate and shape of the $\pi^0 \eta$ mass distribution will definitely help to better understand the nature of scalar resonances.
hep-ph/0106277
Jing Jiang
Tao Han, Jing Jiang (U. of Wisconsin), Marc Sher (William and Mary)
Search for t->ch at e+e- Linear Colliders
12 pages, 5 figures, 2 tables
Phys.Lett. B516 (2001) 337-344
10.1016/S0370-2693(01)00949-2
MADPH-01-1230, WM-01-107
hep-ph
null
We study the rare top-quark decay t->ch, where h is a generic Higgs boson, at a linear collider. If kinematically accessible, all models contain this decay at some level due to quark flavor mixing. Some models, such as Model III of the two-Higgs doublet model, have a tree-level top-charm-Higgs coupling, and the branching ratio is close to 0.5%. Others, such as the MSSM, have a coupling induced at one-loop, and can have a branching ratio in the range of 10^{-5} - 5x10^{-4}. We find that a linear collider of root(s) = 500 GeV and a luminosity of 500 fb^{-1} will begin to be sensitive to this range of the coupling.
[ { "created": "Mon, 25 Jun 2001 15:17:02 GMT", "version": "v1" } ]
2009-11-07
[ [ "Han", "Tao", "", "U. of Wisconsin" ], [ "Jiang", "Jing", "", "U. of Wisconsin" ], [ "Sher", "Marc", "", "William and Mary" ] ]
We study the rare top-quark decay t->ch, where h is a generic Higgs boson, at a linear collider. If kinematically accessible, all models contain this decay at some level due to quark flavor mixing. Some models, such as Model III of the two-Higgs doublet model, have a tree-level top-charm-Higgs coupling, and the branching ratio is close to 0.5%. Others, such as the MSSM, have a coupling induced at one-loop, and can have a branching ratio in the range of 10^{-5} - 5x10^{-4}. We find that a linear collider of root(s) = 500 GeV and a luminosity of 500 fb^{-1} will begin to be sensitive to this range of the coupling.
hep-ph/0703264
Mannque Rho
Mannque Rho
Hidden Local Symmetry and the Vector Manifestation of Chiral Symmetry in Hot and/or Dense Matter
Based in part on talks given at The 1st Asian Triangle Heavy Ion Conference, 2006, Seoul, Korea and at The Yukawa International Seminar (YKIS), 2006, "New Frontiers in QCD", Kyoto, Japan
Prog.Theor.Phys.Suppl.168:519-526,2007
10.1143/PTPS.168.519
null
hep-ph nucl-th
null
The emergence and importance of hidden local symmetry in the structure of hadrons under extreme conditions is discussed. The topics covered are the potentially important role played by an infinite tower of vector mesons encoded in holographic dual QCD (or AdS/QCD) in chiral dynamics of mesons and baryons, in the vector dominance and its violation in EW response functions and the presence of the vector manifestation fixed point and its influence on the properties of hadrons in hot temperature (i.e., in relativistic heavy ion collisions) and in dense matter (i.e., in compact stars). Also discussed are the natural emergence of instantons/skyrmions from the infinite tower of vector mesons coupled to pions in AdS/QCD and their (speculated) role in chiral restoration at high density.
[ { "created": "Sat, 24 Mar 2007 10:55:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Rho", "Mannque", "" ] ]
The emergence and importance of hidden local symmetry in the structure of hadrons under extreme conditions is discussed. The topics covered are the potentially important role played by an infinite tower of vector mesons encoded in holographic dual QCD (or AdS/QCD) in chiral dynamics of mesons and baryons, in the vector dominance and its violation in EW response functions and the presence of the vector manifestation fixed point and its influence on the properties of hadrons in hot temperature (i.e., in relativistic heavy ion collisions) and in dense matter (i.e., in compact stars). Also discussed are the natural emergence of instantons/skyrmions from the infinite tower of vector mesons coupled to pions in AdS/QCD and their (speculated) role in chiral restoration at high density.
1009.4344
Arkadii Kozhevnikov
N.N. Achasov, A.A. Kozhevnikov
Troubles of describing multiple pion production in chiral dynamics
11 pages, 8 figures. The talk given by A.A. Kozhevnikov at the International Seminar "Quarks-2010", Kolomna, Russia, June 6-12, 2010
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Generalized Hidden Local Symmetry (GHLS) model as the chiral model of pseudoscalar, vector, and axial vector mesons and their interactions containing also the couplings of strongly interacting particles with electroweak gauge bosons, is confronted with the ALEPH data on the decay $\tau^-\to\pi^-\pi^-\pi^+\nu_\tau$ and BABAR and CMD data on the reaction $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$. It is shown that both the invariant mass spectrum of final pions in $\tau$ decay calculated in the GHLS framework with the single $a_1(1260)$ resonance and the cross section $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ calculated in the above framework with the single $\rho(770)$ resonance, disagree with the experimental data. The modifications of GHLS model based on inclusion of two additional heavier axial vector mesons $a_1^\prime$, $a_1^{\prime\prime}$ in the $\tau$ decay and the vector mesons $\rho^\prime$, $\rho^{\prime\prime}$ in $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ are shown to be necessary for the good description of the above data.
[ { "created": "Wed, 22 Sep 2010 12:41:49 GMT", "version": "v1" } ]
2010-09-23
[ [ "Achasov", "N. N.", "" ], [ "Kozhevnikov", "A. A.", "" ] ]
Generalized Hidden Local Symmetry (GHLS) model as the chiral model of pseudoscalar, vector, and axial vector mesons and their interactions containing also the couplings of strongly interacting particles with electroweak gauge bosons, is confronted with the ALEPH data on the decay $\tau^-\to\pi^-\pi^-\pi^+\nu_\tau$ and BABAR and CMD data on the reaction $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$. It is shown that both the invariant mass spectrum of final pions in $\tau$ decay calculated in the GHLS framework with the single $a_1(1260)$ resonance and the cross section $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ calculated in the above framework with the single $\rho(770)$ resonance, disagree with the experimental data. The modifications of GHLS model based on inclusion of two additional heavier axial vector mesons $a_1^\prime$, $a_1^{\prime\prime}$ in the $\tau$ decay and the vector mesons $\rho^\prime$, $\rho^{\prime\prime}$ in $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ are shown to be necessary for the good description of the above data.
hep-ph/0205081
Gennaro Corcella
Gennaro Corcella (MPI, Munich), Alexander D. Mitov (Rochester U.)
Top Decay and Bottom Fragmentation in NLO QCD
4 pages, 3 figures. Talk given at XXXVIIth Rencontres de Moriond, QCD and Hadronic Interactions, 16-23 March 2002, Les Arcs, France
null
null
MPI-PhT/2002-18
hep-ph
null
We apply the method of perturbative fragmentation to study bottom fragmentation in top decay. We present the energy spectrum of b-quarks and b-flavoured hadrons in top decay
[ { "created": "Wed, 8 May 2002 14:56:17 GMT", "version": "v1" }, { "created": "Thu, 9 May 2002 13:20:33 GMT", "version": "v2" } ]
2007-05-23
[ [ "Corcella", "Gennaro", "", "MPI, Munich" ], [ "Mitov", "Alexander D.", "", "Rochester U." ] ]
We apply the method of perturbative fragmentation to study bottom fragmentation in top decay. We present the energy spectrum of b-quarks and b-flavoured hadrons in top decay
hep-ph/9402205
Yongseok Oh
Yongseok Oh, Byung-Yoon Park and Dong-Pil Min
Heavy Baryons as Skyrmion with $1/m_Q$ Corrections
REVTeX, 26 pages, 3 figures included (pictex), SNUTP-93/80. (To appear in Physical Review D)
Phys.Rev. D49 (1994) 4649-4658
10.1103/PhysRevD.49.4649
null
hep-ph
null
We take into account the $1/m_Q$ corrections upto $1/N_c$ order in the heavy-meson-soliton bound state approach for heavy baryons. With these corrections, the mass spectra of baryons with $c$-quark as well as of those with $b$-quark are well reproduced. For charmed baryons, however, the correction to the mass spectra amounts to about 300 MeV, which is not small compared to the leading order binding energy, $\sim 800$ MeV.
[ { "created": "Wed, 2 Feb 1994 04:27:58 GMT", "version": "v1" } ]
2009-10-28
[ [ "Oh", "Yongseok", "" ], [ "Park", "Byung-Yoon", "" ], [ "Min", "Dong-Pil", "" ] ]
We take into account the $1/m_Q$ corrections upto $1/N_c$ order in the heavy-meson-soliton bound state approach for heavy baryons. With these corrections, the mass spectra of baryons with $c$-quark as well as of those with $b$-quark are well reproduced. For charmed baryons, however, the correction to the mass spectra amounts to about 300 MeV, which is not small compared to the leading order binding energy, $\sim 800$ MeV.
hep-ph/9608308
Michael Pluemacher
W. Buchmuller and M. Plumacher
Baryon Asymmetry and Neutrino Mixing
latex2e, 10 pages, 3 figures, uses epsfig
Phys.Lett. B389 (1996) 73-77
10.1016/S0370-2693(96)01232-4
DESY 96-158
hep-ph
null
In theories where $B-L$ is a spontaneously broken local symmetry, the cosmological baryon asymmetry can be generated by the out-of-equilibrium decay of heavy Majorana neutrinos. We study this mechanism assuming a similar pattern of mixings and masses for leptons and quarks, as suggested by SO(10) unification. This implies that $B-L$ is broken at the unification scale $\Lambda_{\mbox{\scriptsize GUT}}\sim 10^{16}$ GeV, if $m_{\n_\m} \sim 3\cdot 10^{-3}$eV as preferred by the MSW explanation of the solar neutrino deficit. The observed value of the baryon asymmetry, $n_B/s \sim 10^{-10}$, is then obtained without any fine tuning of parameters.
[ { "created": "Tue, 13 Aug 1996 12:02:57 GMT", "version": "v1" } ]
2009-10-28
[ [ "Buchmuller", "W.", "" ], [ "Plumacher", "M.", "" ] ]
In theories where $B-L$ is a spontaneously broken local symmetry, the cosmological baryon asymmetry can be generated by the out-of-equilibrium decay of heavy Majorana neutrinos. We study this mechanism assuming a similar pattern of mixings and masses for leptons and quarks, as suggested by SO(10) unification. This implies that $B-L$ is broken at the unification scale $\Lambda_{\mbox{\scriptsize GUT}}\sim 10^{16}$ GeV, if $m_{\n_\m} \sim 3\cdot 10^{-3}$eV as preferred by the MSW explanation of the solar neutrino deficit. The observed value of the baryon asymmetry, $n_B/s \sim 10^{-10}$, is then obtained without any fine tuning of parameters.
hep-ph/0602158
Chao-Hsi Chang
Chao-Hsi Chang, Jiao-Kai Chen, Zhen-Yun Fang, Bing-Quan Hu, Xing-Gang Wu
Fragmentation Function and Hadronic Production of the Heavy Supersymmetric Hadrons
20 pages, 9 figures
Eur.Phys.J.C50:969-978,2007
10.1140/epjc/s10052-007-0244-4
null
hep-ph
null
The light top-squark $\sto$ may be the lightest squark and its lifetime may be `long enough' in a kind of SUSY models which have not been ruled out yet experimentally, so colorless `supersymmetric hadrons (superhadrons)' $(\sto \bar{q})$ ($q$ is a quark except $t$-quark) may be formed as long as the light top-squark $\sto$ can be produced. Fragmentation function of $\sto$ to heavy `supersymmetric hadrons (superhadrons)' $(\sto \bar{Q})$ ($\bar{Q}=\bar{c}$ or $\bar{b}$) and the hadronic production of the superhadrons are investigated quantitatively. The fragmentation function is calculated precisely. Due to the difference in spin of the SUSY component, the asymptotic behavior of the fragmentation function is different from those of the existent ones. The fragmentation function is also applied to compute the production of heavy superhadrons at hadronic colliders Tevatron and LHC under the so-called fragmentation approach. The resultant cross-section for the heavy superhadrons is too small to observe at Tevatron, but great enough at LHC, even when all the relevant parameters in the SUSY models are taken within the favored region for the heavy superhadrons. The production of `light superhadrons' $(\sto \bar{q})$ ($q=u, d, s$) is also roughly estimated. It is pointed out that the production cross-sections of the light superhadrons $(\sto \bar{q})$ may be much greater than those of the heavy superhadrons, so that even at Tevatron the light superhadrons may be produced in great quantities.
[ { "created": "Fri, 17 Feb 2006 08:50:50 GMT", "version": "v1" }, { "created": "Tue, 21 Feb 2006 09:58:19 GMT", "version": "v2" }, { "created": "Fri, 8 Jun 2007 03:30:05 GMT", "version": "v3" } ]
2008-11-26
[ [ "Chang", "Chao-Hsi", "" ], [ "Chen", "Jiao-Kai", "" ], [ "Fang", "Zhen-Yun", "" ], [ "Hu", "Bing-Quan", "" ], [ "Wu", "Xing-Gang", "" ] ]
The light top-squark $\sto$ may be the lightest squark and its lifetime may be `long enough' in a kind of SUSY models which have not been ruled out yet experimentally, so colorless `supersymmetric hadrons (superhadrons)' $(\sto \bar{q})$ ($q$ is a quark except $t$-quark) may be formed as long as the light top-squark $\sto$ can be produced. Fragmentation function of $\sto$ to heavy `supersymmetric hadrons (superhadrons)' $(\sto \bar{Q})$ ($\bar{Q}=\bar{c}$ or $\bar{b}$) and the hadronic production of the superhadrons are investigated quantitatively. The fragmentation function is calculated precisely. Due to the difference in spin of the SUSY component, the asymptotic behavior of the fragmentation function is different from those of the existent ones. The fragmentation function is also applied to compute the production of heavy superhadrons at hadronic colliders Tevatron and LHC under the so-called fragmentation approach. The resultant cross-section for the heavy superhadrons is too small to observe at Tevatron, but great enough at LHC, even when all the relevant parameters in the SUSY models are taken within the favored region for the heavy superhadrons. The production of `light superhadrons' $(\sto \bar{q})$ ($q=u, d, s$) is also roughly estimated. It is pointed out that the production cross-sections of the light superhadrons $(\sto \bar{q})$ may be much greater than those of the heavy superhadrons, so that even at Tevatron the light superhadrons may be produced in great quantities.
1605.07453
Wei Chen
Hua-Xing Chen, Dan Zhou, Wei Chen, Xiang Liu, and Shi-Lin Zhu
Searching for hidden-charm baryonium signals in QCD sum rules
7 pages, 5 figures, 1 table. Accepted by Eur. Phys. J. C
Eur.Phys.J. C76 (2016) no.11, 602
10.1140/epjc/s10052-016-4459-0
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give an explicit QCD sum rule investigation to hidden-charm baryonium states with the quark content $u\bar u d\bar d c\bar c$, spin $J=0/1/2/3$, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. We find some of them can couple to hidden-charm baryonium states, using which we evaluate the masses of the lowest-lying hidden-charm baryonium states with quantum numbers $J^P=2^-/3^-/0^+/1^+/2^+$ to be around 5.0 GeV. We suggest to search for hidden-charm baryonium states, especially the one of $J=3^-$, in the $D$-wave $J/\psi \pi \pi$ and $P$-wave $J/\psi \rho$ and $J/\psi \omega$ channels in this energy region.
[ { "created": "Tue, 24 May 2016 13:42:37 GMT", "version": "v1" }, { "created": "Fri, 4 Nov 2016 03:51:05 GMT", "version": "v2" } ]
2016-11-10
[ [ "Chen", "Hua-Xing", "" ], [ "Zhou", "Dan", "" ], [ "Chen", "Wei", "" ], [ "Liu", "Xiang", "" ], [ "Zhu", "Shi-Lin", "" ] ]
We give an explicit QCD sum rule investigation to hidden-charm baryonium states with the quark content $u\bar u d\bar d c\bar c$, spin $J=0/1/2/3$, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. We find some of them can couple to hidden-charm baryonium states, using which we evaluate the masses of the lowest-lying hidden-charm baryonium states with quantum numbers $J^P=2^-/3^-/0^+/1^+/2^+$ to be around 5.0 GeV. We suggest to search for hidden-charm baryonium states, especially the one of $J=3^-$, in the $D$-wave $J/\psi \pi \pi$ and $P$-wave $J/\psi \rho$ and $J/\psi \omega$ channels in this energy region.
0810.4075
Ivanov Dmitry
D.Yu. Ivanov, V.M. Braun and A. Sch\"afer
Diffractive jets production in pp-collisions
Presented at International Workshop on Diffraction in High-Energy Physics, La Londe-les-Maures, France, September 9 - 14, 2008
null
10.1063/1.3122210
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the exclusive diffractive dissociation of a proton into three jets with large transverse momenta in the double-logarithmic approximation of perturbative QCD. This process is sensitive to the proton unintegrated gluon distribution at small x and to the proton light-cone distribution amplitudes. According to our estimates, an observation of such processes in the early runs at LHC is feasible for jet transverse momenta of the order of 5 GeV.
[ { "created": "Wed, 22 Oct 2008 14:29:44 GMT", "version": "v1" } ]
2009-11-13
[ [ "Ivanov", "D. Yu.", "" ], [ "Braun", "V. M.", "" ], [ "Schäfer", "A.", "" ] ]
We consider the exclusive diffractive dissociation of a proton into three jets with large transverse momenta in the double-logarithmic approximation of perturbative QCD. This process is sensitive to the proton unintegrated gluon distribution at small x and to the proton light-cone distribution amplitudes. According to our estimates, an observation of such processes in the early runs at LHC is feasible for jet transverse momenta of the order of 5 GeV.
hep-ph/9910382
Enrique Ruiz Arriola
E. Ruiz Arriola
On the Structure Functions of Mesons and Baryons in a Chiral Quark Model
(LaTeX) 12 pages, 1 figure, Talk given at the Mini-Workshop "Hadrons as Solitons", Bled (Slovenia) July 9-17, 1999
null
null
UG-DFM-3/99
hep-ph
null
This research summarizes work done by myself (Nucl.Phys.{\bf A641} (1998)461), or in collaboration with R. M. Davidson (Phys.Lett.{\bf B348}(1995)163) and H. Weigel and L. Gamberg (Nucl.Phys.{\bf B560}(1999)xx). I will discuss several topics related with the computation of structure functions in the quark model in general and its perturbative evolution. In particular, I address this topic in the Nambu-Jona-Lasinio model of hadrons, where the nucleon is constructed as a soliton. I show that the handling of the regularization procedure is crucial in order to obtain exact scaling in the Bjorken limit and fulfillment of sum rules. I also include some problems concerning the general validity of quark model calculations.
[ { "created": "Mon, 18 Oct 1999 12:23:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Arriola", "E. Ruiz", "" ] ]
This research summarizes work done by myself (Nucl.Phys.{\bf A641} (1998)461), or in collaboration with R. M. Davidson (Phys.Lett.{\bf B348}(1995)163) and H. Weigel and L. Gamberg (Nucl.Phys.{\bf B560}(1999)xx). I will discuss several topics related with the computation of structure functions in the quark model in general and its perturbative evolution. In particular, I address this topic in the Nambu-Jona-Lasinio model of hadrons, where the nucleon is constructed as a soliton. I show that the handling of the regularization procedure is crucial in order to obtain exact scaling in the Bjorken limit and fulfillment of sum rules. I also include some problems concerning the general validity of quark model calculations.
hep-ph/9905576
Sreerup Raychaudhuri fc phy
Sreerup Raychaudhuri (IIT, Kanpur)
Trilinear R-Parity Violation: Theory to Experiment
20 pages, LaTeX, 6 postscript figures; Expanded version of an Invited Talk delivered at the 13th Topical Conference on Hadron Collider Physics, Mumbai, January 1999
null
null
IITK-PHY-99-51
hep-ph
null
Supersymmetric models without conservation of R-parity are reviewed and low-energy constraints on the extra trilinear couplings listed. Current searches at the LEP, Tevatron and HERA colliders are then summed up. Prospects for further study, especially at future colliders, are briefly touched upon.
[ { "created": "Mon, 31 May 1999 20:24:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Raychaudhuri", "Sreerup", "", "IIT, Kanpur" ] ]
Supersymmetric models without conservation of R-parity are reviewed and low-energy constraints on the extra trilinear couplings listed. Current searches at the LEP, Tevatron and HERA colliders are then summed up. Prospects for further study, especially at future colliders, are briefly touched upon.
1810.03332
Bin Yang
Bin Yang, Lu Meng and Shi-Lin Zhu
Hadronic Molecular States Composed of Spin-$3\over 2$ Singly Charmed Baryons
18 pages, 7 figures
null
10.1140/epja/i2019-12686-5
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possible deuteron-like molecules composed of a pair of charmed spin-$\frac{3}{2}$ baryons, or one charmed baryon and one charmed antibaryon within the one-boson-exchange (OBE) model. For the spin singlet and triplet systems, we consider the couple channel effect between systems with different orbital angular momentum. Most of the systems have binding solutions. The couple channel effect plays a significant role in the formation of some loosely bound states. The possible molecular states of $\Omega_c^*\Omega_c^*$ and $\Omega_c^*\bar{\Omega}_c^*$ might be stable once produced.
[ { "created": "Mon, 8 Oct 2018 09:02:46 GMT", "version": "v1" }, { "created": "Wed, 13 Feb 2019 05:48:14 GMT", "version": "v2" } ]
2019-03-27
[ [ "Yang", "Bin", "" ], [ "Meng", "Lu", "" ], [ "Zhu", "Shi-Lin", "" ] ]
We investigate the possible deuteron-like molecules composed of a pair of charmed spin-$\frac{3}{2}$ baryons, or one charmed baryon and one charmed antibaryon within the one-boson-exchange (OBE) model. For the spin singlet and triplet systems, we consider the couple channel effect between systems with different orbital angular momentum. Most of the systems have binding solutions. The couple channel effect plays a significant role in the formation of some loosely bound states. The possible molecular states of $\Omega_c^*\Omega_c^*$ and $\Omega_c^*\bar{\Omega}_c^*$ might be stable once produced.
1506.04612
Marco Frasca
Marco Frasca
Running mass of the gluon propagator in the Landau gauge
15 pages, 3 figures. Added some references and exposed, in the introduction, the role of the scaling solution
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gluon propagator in the infrared limit, computed in the Landau gauge, can be cast into an universal form with a running mass for the gluon. In this way we are able to show that all the proposals appeared so far in literature are equivalent and describe the same physics. In this way, it appears essential to reach a general agreement about the interpretation of such results. We discuss the points that make difficult to agree on a similar view about this.
[ { "created": "Mon, 15 Jun 2015 14:30:29 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 2015 07:52:19 GMT", "version": "v2" } ]
2015-06-18
[ [ "Frasca", "Marco", "" ] ]
Gluon propagator in the infrared limit, computed in the Landau gauge, can be cast into an universal form with a running mass for the gluon. In this way we are able to show that all the proposals appeared so far in literature are equivalent and describe the same physics. In this way, it appears essential to reach a general agreement about the interpretation of such results. We discuss the points that make difficult to agree on a similar view about this.
1709.10370
Colferai Dimitri Dr
Dimitri Colferai, Federico Deganutti and Alessandro Niccoli
Improved theoretical description of Mueller-Navelet jets at LHC
8 pages, 6 figures, talk presented at the Low x workshop, June 13-18 2017, Bari, Italy
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for improving the phenomenological description of Mueller-Navelet jets at LHC, which is based on matching the BFKL resummation with fixed order calculations. We point out the need of a consistent identification of jets between experimental measurements and theoretical descriptions. We hope as well to motivate an extensive analysis of MN jets at LHC in run 2.
[ { "created": "Fri, 29 Sep 2017 12:37:25 GMT", "version": "v1" } ]
2017-10-02
[ [ "Colferai", "Dimitri", "" ], [ "Deganutti", "Federico", "" ], [ "Niccoli", "Alessandro", "" ] ]
We present a method for improving the phenomenological description of Mueller-Navelet jets at LHC, which is based on matching the BFKL resummation with fixed order calculations. We point out the need of a consistent identification of jets between experimental measurements and theoretical descriptions. We hope as well to motivate an extensive analysis of MN jets at LHC in run 2.
1710.01930
Jan Maelger
J. Maelger, U. Reinosa, J. Serreau
A perturbative study of the QCD phase diagram for heavy quarks at nonzero chemical potential: two-loop corrections
26 pages, 16 figures
Phys. Rev. D 97, 074027 (2018)
10.1103/PhysRevD.97.074027
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend a previous investigation of the QCD phase diagram with heavy quarks in the context of background field methods by including the two-loop corrections to the background field effective potential. The nonperturbative dynamics in the pure-gauge sector is modeled by a phenomenological gluon mass term in the Landau-DeWitt gauge-fixed action, which results in an improved perturbative expansion. We investigate the phase diagram at nonzero temperature and (real or imaginary) chemical potential. Two-loop corrections yield an improved agreement with lattice data as compared to the leading-order results. We also compare with the results of nonperturbative approaches. We further study the equation of state as well as the thermodynamic stability of the system at two-loop order. Finally, we show, using simple thermodynamic arguments, that the behavior of the Polyakov loops as functions of the chemical potential complies with their interpretation in terms of quark and anti-quark free energies.
[ { "created": "Thu, 5 Oct 2017 09:16:59 GMT", "version": "v1" } ]
2018-05-02
[ [ "Maelger", "J.", "" ], [ "Reinosa", "U.", "" ], [ "Serreau", "J.", "" ] ]
We extend a previous investigation of the QCD phase diagram with heavy quarks in the context of background field methods by including the two-loop corrections to the background field effective potential. The nonperturbative dynamics in the pure-gauge sector is modeled by a phenomenological gluon mass term in the Landau-DeWitt gauge-fixed action, which results in an improved perturbative expansion. We investigate the phase diagram at nonzero temperature and (real or imaginary) chemical potential. Two-loop corrections yield an improved agreement with lattice data as compared to the leading-order results. We also compare with the results of nonperturbative approaches. We further study the equation of state as well as the thermodynamic stability of the system at two-loop order. Finally, we show, using simple thermodynamic arguments, that the behavior of the Polyakov loops as functions of the chemical potential complies with their interpretation in terms of quark and anti-quark free energies.
1912.04329
Kanchan Khemchandani
K. P. Khemchandani, A. Martinez Torres, J. A. Oller
Hyperon resonances and meson-baryon interactions in isospin 1
Contribution to the Hadron 2019 conference proceedings
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we extend our formalism to study meson-baryon interactions by including $s$- and $u$-channel diagrams for pseudoscalar-baryon systems. We study the coupled systems with strangeness $-1$ and focus on studying the isospin-1 resonance(s), especially in the energy region around 1400 MeV. By constraining the model parameters to fit the cross section data available on several processes involving relevant channels, we find resonances in the isoscalar as well as the isovector sector in the energy region around 1400 MeV.
[ { "created": "Mon, 9 Dec 2019 19:17:02 GMT", "version": "v1" }, { "created": "Wed, 19 Feb 2020 21:11:10 GMT", "version": "v2" } ]
2020-02-21
[ [ "Khemchandani", "K. P.", "" ], [ "Torres", "A. Martinez", "" ], [ "Oller", "J. A.", "" ] ]
In this work we extend our formalism to study meson-baryon interactions by including $s$- and $u$-channel diagrams for pseudoscalar-baryon systems. We study the coupled systems with strangeness $-1$ and focus on studying the isospin-1 resonance(s), especially in the energy region around 1400 MeV. By constraining the model parameters to fit the cross section data available on several processes involving relevant channels, we find resonances in the isoscalar as well as the isovector sector in the energy region around 1400 MeV.
hep-ph/9510244
Sergio Lupia
Sergio Lupia (Max-Planck-Institut fuer Physik, Muenchen)
Moment analysis of energy spectra and the effect of running coupling
12 pages, LaTeX, uses epsfig.sty, 3 figures appended as uuencoded Z-compressed tarred PS-files, to be published in Proc. of XXVth International Symposium on Multiparticle Dynamics, Stara Lesna, Slovakia, September 12-16, 1995
null
null
MPI-PhT/95-94
hep-ph
null
Single particle inclusive energy spectra in $e^+e^-$ annihilation are analyzed in terms of moments. By assuming Local Parton Hadron Duality (LPHD), experimental data in a wide c.m. energy range from 3 GeV up to LEP energy are compared to the theoretical predictions of Modified Leading Log Approximation (MLLA) of QCD with and without taking into account the running of $\alpha_s$. MLLA with running coupling (Limiting Spectrum) is found to reproduce experimental results very well, while the model with fixed coupling is inconsistent with data. Rescaled cumulants are shown to be sensitive to the running of $\alpha_s$ in the asymptotic regime, while the Lorentz-invariant distribution, $E dn/d^3p$, points out this effect at very small energy $E$ of few hundreds MeV. These results give a direct evidence of the running of the QCD coupling in inclusive energy spectra and lend further support to the LPHD picture.
[ { "created": "Fri, 6 Oct 1995 15:37:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lupia", "Sergio", "", "Max-Planck-Institut fuer Physik, Muenchen" ] ]
Single particle inclusive energy spectra in $e^+e^-$ annihilation are analyzed in terms of moments. By assuming Local Parton Hadron Duality (LPHD), experimental data in a wide c.m. energy range from 3 GeV up to LEP energy are compared to the theoretical predictions of Modified Leading Log Approximation (MLLA) of QCD with and without taking into account the running of $\alpha_s$. MLLA with running coupling (Limiting Spectrum) is found to reproduce experimental results very well, while the model with fixed coupling is inconsistent with data. Rescaled cumulants are shown to be sensitive to the running of $\alpha_s$ in the asymptotic regime, while the Lorentz-invariant distribution, $E dn/d^3p$, points out this effect at very small energy $E$ of few hundreds MeV. These results give a direct evidence of the running of the QCD coupling in inclusive energy spectra and lend further support to the LPHD picture.
1907.06735
Le Tho Hue
H. T. Hung, T. T. Hong, H. H. Phuong, H. L. T. Mai, L. T.Hue
Neutral Higgs decays $H \rightarrow Z \gamma,\gamma\gamma$ in 3-3-1 models
Version accepted for publication in PRD
Phys. Rev. D 100, 075014 (2019)
10.1103/PhysRevD.100.075014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $\gamma\gamma$ and $Z\gamma$ will be discussed in the framework of the 3-3-1 models based on a recent work~\cite{Okada:2016whh}, where the Higgs sector becomes effectively the same as that in the two Higgs doublet models (2HDM) after the first symmetry breaking from $SU(3)_L$ scale into the electroweak scale. For large $SU(3)_L$ scale $v_3\simeq10$ TeV, dominant one-loop contributions to the two decay amplitudes arise from only the single charged Higgs boson predicted by the 2HDM, leading to that experimental constraint on the signal strength $\mu^{331}_{\gamma\gamma}$ of the Standard Model-like Higgs boson decay $h\rightarrow \gamma\gamma$ will result in a strict upper bound on the signal strength $\mu^{331}_{Z\gamma}$ of the decay $h\rightarrow\, Z\gamma$. For a particular model with lower $v_3$ around 3 TeV, contributions from heavy charged gauge and Higgs bosons may have the same order, therefore may give strong destructive or constructive correlations. As a by-product, a deviation from the SM prediction $|\mu^{331}_{\gamma\gamma}-1| \le 0.04$ still allows $|\mu^{331}_{Z\gamma}-1|$ to reach values near 0.1. We also show that there exists an $CP$-even neutral Higgs boson $h^0_3$ predicted by the 3-3-1 models, but beyond the 2HDM, has an interesting property that the branching ratio Br$(h^0_3\rightarrow \gamma\gamma)$ is very sensitive to the parameter $\beta$ used to distinguish different 3-3-1 models.
[ { "created": "Mon, 15 Jul 2019 20:28:31 GMT", "version": "v1" }, { "created": "Mon, 7 Oct 2019 08:43:52 GMT", "version": "v2" } ]
2019-10-16
[ [ "Hung", "H. T.", "" ], [ "Hong", "T. T.", "" ], [ "Phuong", "H. H.", "" ], [ "Mai", "H. L. T.", "" ], [ "Hue", "L. T.", "" ] ]
The significance of new physics appearing in the loop-induced decays of neutral Higgs bosons into pairs of dibosons $\gamma\gamma$ and $Z\gamma$ will be discussed in the framework of the 3-3-1 models based on a recent work~\cite{Okada:2016whh}, where the Higgs sector becomes effectively the same as that in the two Higgs doublet models (2HDM) after the first symmetry breaking from $SU(3)_L$ scale into the electroweak scale. For large $SU(3)_L$ scale $v_3\simeq10$ TeV, dominant one-loop contributions to the two decay amplitudes arise from only the single charged Higgs boson predicted by the 2HDM, leading to that experimental constraint on the signal strength $\mu^{331}_{\gamma\gamma}$ of the Standard Model-like Higgs boson decay $h\rightarrow \gamma\gamma$ will result in a strict upper bound on the signal strength $\mu^{331}_{Z\gamma}$ of the decay $h\rightarrow\, Z\gamma$. For a particular model with lower $v_3$ around 3 TeV, contributions from heavy charged gauge and Higgs bosons may have the same order, therefore may give strong destructive or constructive correlations. As a by-product, a deviation from the SM prediction $|\mu^{331}_{\gamma\gamma}-1| \le 0.04$ still allows $|\mu^{331}_{Z\gamma}-1|$ to reach values near 0.1. We also show that there exists an $CP$-even neutral Higgs boson $h^0_3$ predicted by the 3-3-1 models, but beyond the 2HDM, has an interesting property that the branching ratio Br$(h^0_3\rightarrow \gamma\gamma)$ is very sensitive to the parameter $\beta$ used to distinguish different 3-3-1 models.
hep-ph/0610067
T. Becher
Thomas Becher and Matthias Neubert
Analysis of Br(B-->X_s gamma) at NNLO with a Cut on Photon Energy
4 pages, 1 figure
Phys.Rev.Lett.98:022003,2007
10.1103/PhysRevLett.98.022003
CLNS 06/1979, FERMILAB-PUB-06-364-T
hep-ph
null
By combining a recent estimate of the total B-->X_s gamma branching fraction at O(alpha_s^2) with a detailed analysis of the effects of a cut E_gamma>1.6GeV on photon energy, a prediction for the partial B-->X_s gamma branching fraction at next-to-next-to-leading order in renormalization-group improved perturbation theory is obtained, in which contributions from all relevant scales are properly factorized. The result Br(B-->X_s gamma)=(2.98+-0.26)x10^{-4} is about 1.4 sigma lower than the experimental world average. This opens a window for significant New Physics contributions in rare radiative B decays.
[ { "created": "Thu, 5 Oct 2006 19:08:49 GMT", "version": "v1" } ]
2008-11-26
[ [ "Becher", "Thomas", "" ], [ "Neubert", "Matthias", "" ] ]
By combining a recent estimate of the total B-->X_s gamma branching fraction at O(alpha_s^2) with a detailed analysis of the effects of a cut E_gamma>1.6GeV on photon energy, a prediction for the partial B-->X_s gamma branching fraction at next-to-next-to-leading order in renormalization-group improved perturbation theory is obtained, in which contributions from all relevant scales are properly factorized. The result Br(B-->X_s gamma)=(2.98+-0.26)x10^{-4} is about 1.4 sigma lower than the experimental world average. This opens a window for significant New Physics contributions in rare radiative B decays.
0706.2377
Alejandro Ayala
Alejandro Ayala (ICN-UNAM), J. Magnin (CBPF), Luis Manuel Montano (CINVESTAV) and Eduardo Rojas (ICN-UNAM)
Collisional parton energy loss in a finite size QCD medium revisited: Off mass-shell effects
9 pages, 4 figures. Enlarged discussion. References added. Version to appear in Phys. Rev. C
Phys.Rev.C77:044904,2008
10.1103/PhysRevC.77.044904
null
hep-ph
null
We study the collisional energy loss mechanism for particles produced off mass-shell in a finite size QCD medium. The off mass-shell effects introduced are to consider particles produced in wave packets instead of plane waves and the length scale associated to an in-medium particles' life-time. We show that these effects reduce the energy loss as compared to the case when the particles are described as freely propagating from the source. The reduction of the energy loss is stronger as this scale becomes of the order or smaller than the medium size. We discuss possible consequences of the result on the description of the energy loss process in the parton recombination scenario.
[ { "created": "Fri, 15 Jun 2007 22:08:12 GMT", "version": "v1" }, { "created": "Tue, 25 Mar 2008 18:41:52 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ayala", "Alejandro", "", "ICN-UNAM" ], [ "Magnin", "J.", "", "CBPF" ], [ "Montano", "Luis Manuel", "", "CINVESTAV" ], [ "Rojas", "Eduardo", "", "ICN-UNAM" ] ]
We study the collisional energy loss mechanism for particles produced off mass-shell in a finite size QCD medium. The off mass-shell effects introduced are to consider particles produced in wave packets instead of plane waves and the length scale associated to an in-medium particles' life-time. We show that these effects reduce the energy loss as compared to the case when the particles are described as freely propagating from the source. The reduction of the energy loss is stronger as this scale becomes of the order or smaller than the medium size. We discuss possible consequences of the result on the description of the energy loss process in the parton recombination scenario.
1306.0695
Christian Hambrock
Christian Hambrock
Exotic Heavy Quark Spectroscopy - Theory Interpretation vs Data
Proceedings, Beauty 2013, Bologna
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An overview over recent spectroscopy results in comparison with data is given. We focus on the exotica Z_b(10610), Z_b(10650) and Y_b(10890) in the bottom sector and discuss a possible connection to the exotica in the charm sector, namely to the resonances Y_c(4260) and Z_c(3900). Furthermore, future prospects for the determination of the nature of Y_b(10890) are outlined.
[ { "created": "Tue, 4 Jun 2013 08:04:54 GMT", "version": "v1" } ]
2013-06-05
[ [ "Hambrock", "Christian", "" ] ]
An overview over recent spectroscopy results in comparison with data is given. We focus on the exotica Z_b(10610), Z_b(10650) and Y_b(10890) in the bottom sector and discuss a possible connection to the exotica in the charm sector, namely to the resonances Y_c(4260) and Z_c(3900). Furthermore, future prospects for the determination of the nature of Y_b(10890) are outlined.
1310.2608
Haipeng An
Haipeng An, Yue Zhang
Baryogenesis Once More, Inside LHC
References added, new acknowledgement added, some paragraphs reorganized for conciseness
null
null
CALT 68-2863
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the feasibility of directly detecting a generation mechanism of the cosmic baryon asymmetry, by repeating the same particle physics process inside the LHC. We propose a framework with R-parity and CP violating squark decays responsible for baryogenesis, which can be embedded in supersymmetric models and is partly motivated by naturalness. We argue that the baryon number generation here is closely related to lepton charge asymmetry on the resonance. We emphasize the importance of the single charged lepton plus multijet channel in the absence of significant missing energy in search of such a scenario.
[ { "created": "Wed, 9 Oct 2013 20:00:01 GMT", "version": "v1" }, { "created": "Thu, 24 Oct 2013 05:19:50 GMT", "version": "v2" } ]
2013-10-25
[ [ "An", "Haipeng", "" ], [ "Zhang", "Yue", "" ] ]
We investigate the feasibility of directly detecting a generation mechanism of the cosmic baryon asymmetry, by repeating the same particle physics process inside the LHC. We propose a framework with R-parity and CP violating squark decays responsible for baryogenesis, which can be embedded in supersymmetric models and is partly motivated by naturalness. We argue that the baryon number generation here is closely related to lepton charge asymmetry on the resonance. We emphasize the importance of the single charged lepton plus multijet channel in the absence of significant missing energy in search of such a scenario.
1312.1627
Tiziano Peraro
Hans van Deurzen, Gionata Luisoni, Pierpaolo Mastrolia, Edoardo Mirabella, Giovanni Ossola, Tiziano Peraro, Ulrich Schubert
Multi-loop Integrand Reduction via Multivariate Polynomial Division
Presented at the conferences: EPSHEP 2013, Matter to the Deepest 2013, and RADCOR 2013
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present recent developments on the topic of the integrand reduction of scattering amplitudes. Integrand-level methods allow to express an amplitude as a linear combination of Master Integrals, by performing operations on the corresponding integrands. This approach has already been successfully applied and automated at one loop, and recently extended to higher loops. We describe a coherent framework based on simple concepts of algebraic geometry, such as multivariate polynomial division, which can be used in order to obtain the integrand decomposition of any amplitude at any loop order. In the one-loop case, we discuss an improved reduction algorithm, based on the application of the Laurent series expansion to the integrands, which has been implemented in the semi-numerical library Ninja. At two loops, we present the reduction of five-point amplitudes in N=4 SYM, with a unitarity-based construction of the integrand. We also describe the multi-loop divide-and-conquer approach, which can always be used to find the integrand decomposition of any Feynman graph, regardless of the form and the complexity of the integrand, with purely algebraic operations.
[ { "created": "Thu, 5 Dec 2013 17:42:43 GMT", "version": "v1" } ]
2013-12-06
[ [ "van Deurzen", "Hans", "" ], [ "Luisoni", "Gionata", "" ], [ "Mastrolia", "Pierpaolo", "" ], [ "Mirabella", "Edoardo", "" ], [ "Ossola", "Giovanni", "" ], [ "Peraro", "Tiziano", "" ], [ "Schubert", "Ulrich", "" ] ]
We present recent developments on the topic of the integrand reduction of scattering amplitudes. Integrand-level methods allow to express an amplitude as a linear combination of Master Integrals, by performing operations on the corresponding integrands. This approach has already been successfully applied and automated at one loop, and recently extended to higher loops. We describe a coherent framework based on simple concepts of algebraic geometry, such as multivariate polynomial division, which can be used in order to obtain the integrand decomposition of any amplitude at any loop order. In the one-loop case, we discuss an improved reduction algorithm, based on the application of the Laurent series expansion to the integrands, which has been implemented in the semi-numerical library Ninja. At two loops, we present the reduction of five-point amplitudes in N=4 SYM, with a unitarity-based construction of the integrand. We also describe the multi-loop divide-and-conquer approach, which can always be used to find the integrand decomposition of any Feynman graph, regardless of the form and the complexity of the integrand, with purely algebraic operations.
1508.03172
Carlo Giunti Dr.
C. Giunti and E. M. Zavanin
Appearance-Disappearance Relation in 3+$N_{s}$ Short-Baseline Neutrino Oscillations
6 pages; final version to be published in Mod. Phys. Lett. A
null
10.1142/S0217732316500036
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the relation between the amplitudes of short-baseline appearance and disappearance oscillations in 3+$N_{s}$ neutrino mixing schemes which is the origin of the appearance-disappearance tension that is found from the analysis of the existing data in any 3+$N_{s}$ neutrino mixing scheme. We illustrate the power of the relation to reveal the appearance-disappearance tension in the cases of 3+1 and 3+2 mixing using the results of global fits of short-baseline neutrino oscillation data.
[ { "created": "Thu, 13 Aug 2015 11:06:52 GMT", "version": "v1" }, { "created": "Mon, 14 Dec 2015 16:28:01 GMT", "version": "v2" } ]
2016-01-20
[ [ "Giunti", "C.", "" ], [ "Zavanin", "E. M.", "" ] ]
We derive the relation between the amplitudes of short-baseline appearance and disappearance oscillations in 3+$N_{s}$ neutrino mixing schemes which is the origin of the appearance-disappearance tension that is found from the analysis of the existing data in any 3+$N_{s}$ neutrino mixing scheme. We illustrate the power of the relation to reveal the appearance-disappearance tension in the cases of 3+1 and 3+2 mixing using the results of global fits of short-baseline neutrino oscillation data.
hep-ph/0301135
Patricia Ball
Patricia Ball and Emi Kou
B->gamma e nu Transitions from QCD Sum Rules
13 pages, 5 figures
JHEP 0304 (2003) 029
10.1088/1126-6708/2003/04/029
IPPP/02/72
hep-ph
null
B->gamma e nu transitions have recently been studied in the framework of QCD factorization. The attractiveness of this channel for such an analysis lies in the fact that, at least in the heavy quark limit, the only hadron involved is the B meson itself, so one expects a very simple description of the form factor in terms of a convolution of the B meson distribution amplitude with a perturbative kernel. This description, however, does not include contributions suppressed by powers of the b quark mass. In this letter, we calculate corrections to the factorized expression which are induced by the ``soft'' hadronic component of the photon. We demonstrate that the power-suppression of these terms is numerically not effective for physical values of the $b$ quark mass and that they increase the form factor by about 30% at zero momentum transfer. We also derive a sum rule for lambda_B, the first negative moment of the B meson distribution amplitude, and find lambda_B = 0.6 GeV (to leading order in QCD).
[ { "created": "Fri, 17 Jan 2003 13:56:06 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ball", "Patricia", "" ], [ "Kou", "Emi", "" ] ]
B->gamma e nu transitions have recently been studied in the framework of QCD factorization. The attractiveness of this channel for such an analysis lies in the fact that, at least in the heavy quark limit, the only hadron involved is the B meson itself, so one expects a very simple description of the form factor in terms of a convolution of the B meson distribution amplitude with a perturbative kernel. This description, however, does not include contributions suppressed by powers of the b quark mass. In this letter, we calculate corrections to the factorized expression which are induced by the ``soft'' hadronic component of the photon. We demonstrate that the power-suppression of these terms is numerically not effective for physical values of the $b$ quark mass and that they increase the form factor by about 30% at zero momentum transfer. We also derive a sum rule for lambda_B, the first negative moment of the B meson distribution amplitude, and find lambda_B = 0.6 GeV (to leading order in QCD).
1808.05429
Fernand M Renard
Fernand M. Renard
Further tests of special interactions of massive particles from the Z polarization rate in $e^+e^-\to Zt\bar t$ and in $e^+e^-\to ZW^+W^-$
10 pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose further tests of the occurence of scale dependent heavy particle masses (Z,W,t) and of strong final state interactions by comparing Z longitudinal polarization rates in different kinematical distributions of the $e^+e^-\to Zt\bar t$ and in $e^+e^-\to ZW^+W^-$ processes.
[ { "created": "Thu, 16 Aug 2018 11:46:22 GMT", "version": "v1" } ]
2018-08-17
[ [ "Renard", "Fernand M.", "" ] ]
We propose further tests of the occurence of scale dependent heavy particle masses (Z,W,t) and of strong final state interactions by comparing Z longitudinal polarization rates in different kinematical distributions of the $e^+e^-\to Zt\bar t$ and in $e^+e^-\to ZW^+W^-$ processes.
2102.05048
William J. Torres Bobadilla Dr.
William J. Torres Bobadilla
Loop-tree duality from vertices and edges
26 pages, 3 figures. v2: added all loop causal representation + corrected a few typos. v3: references added; matches published version
null
10.1007/JHEP04(2021)183
MPP-2021-14
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The causal representation of multi-loop scattering amplitudes, obtained from the application of the loop-tree duality formalism, comprehensively elucidates, at integrand level, the behaviour of only physical singularities. This representation is found to manifest compact expressions for multi-loop topologies that have the same number of \textit{vertices}. Interestingly, integrands considered in former studies, with up-to six vertices and $L$ internal lines, display the same structure of up-to four-loop ones. The former is an insight that there should be a correspondence between vertices and the collection of internal lines, \textit{edges}, that characterise a multi-loop topology. By virtue of this relation, in this paper, we embrace an approach to properly classify multi-loop topologies according to vertices and edges. Differently from former studies, we consider the most general topologies, by connecting vertices and edges in all possible ways. Likewise, we provide a procedure to generate causal representation of multi-loop topologies by considering the structure of causal propagators. Explicit causal representations of loop topologies with up-to nine vertices are provided.
[ { "created": "Tue, 9 Feb 2021 19:00:00 GMT", "version": "v1" }, { "created": "Mon, 15 Feb 2021 06:37:45 GMT", "version": "v2" }, { "created": "Tue, 22 Jun 2021 16:12:38 GMT", "version": "v3" } ]
2021-06-23
[ [ "Bobadilla", "William J. Torres", "" ] ]
The causal representation of multi-loop scattering amplitudes, obtained from the application of the loop-tree duality formalism, comprehensively elucidates, at integrand level, the behaviour of only physical singularities. This representation is found to manifest compact expressions for multi-loop topologies that have the same number of \textit{vertices}. Interestingly, integrands considered in former studies, with up-to six vertices and $L$ internal lines, display the same structure of up-to four-loop ones. The former is an insight that there should be a correspondence between vertices and the collection of internal lines, \textit{edges}, that characterise a multi-loop topology. By virtue of this relation, in this paper, we embrace an approach to properly classify multi-loop topologies according to vertices and edges. Differently from former studies, we consider the most general topologies, by connecting vertices and edges in all possible ways. Likewise, we provide a procedure to generate causal representation of multi-loop topologies by considering the structure of causal propagators. Explicit causal representations of loop topologies with up-to nine vertices are provided.
hep-ph/9407363
null
V.A. Litvin, S.R. Slabospitsky
LEP $e^{+}\,e^{-}\,\rightarrow\,\mu^{+}\, \mu^{-}\,\gamma\,\gamma$ events and their consequences at future $e^+e^-$ colliders
Latex, 10 pages, Preprint IHEP 94-22, Protvino, 1994
Int.J.Mod.Phys.A10:2053-2066,1995
10.1142/S0217751X95000991
null
hep-ph
null
The $e^{+}\,e^{-}\,\rightarrow\,l^{+}\, \l^{-}\,\gamma\,\gamma$ anomalous events, detected by $L3$ de\-tec\-tor at $e^+ e^-$ $CERN-LEP$ collider have been analysed. It has been shown that the interpretation of such events as a manifestation of scalar (pseudoscalar) resonance with the mass of 60 GeV contradicts other experimental data. In case of a possible existence that kind of resonance, the perspectives to discover one in some processes at future $e^+e^-$ colliders have been discussed.
[ { "created": "Mon, 25 Jul 1994 14:17:04 GMT", "version": "v1" } ]
2009-09-25
[ [ "Litvin", "V. A.", "" ], [ "Slabospitsky", "S. R.", "" ] ]
The $e^{+}\,e^{-}\,\rightarrow\,l^{+}\, \l^{-}\,\gamma\,\gamma$ anomalous events, detected by $L3$ de\-tec\-tor at $e^+ e^-$ $CERN-LEP$ collider have been analysed. It has been shown that the interpretation of such events as a manifestation of scalar (pseudoscalar) resonance with the mass of 60 GeV contradicts other experimental data. In case of a possible existence that kind of resonance, the perspectives to discover one in some processes at future $e^+e^-$ colliders have been discussed.
hep-ph/0312191
Thomas D. Cohen
Thomas D. Cohen
The theta^+ baryon in soliton models: large Nc QCD and the validity of rigid-rotor quantization
19 pages; A shorter more readable version
Phys.Rev. D70 (2004) 014011
10.1103/PhysRevD.70.014011
null
hep-ph hep-th nucl-th
null
A light collective theta+ baryon state (with strangeness +1) was predicted via rigid-rotor collective quantization of SU(3) chiral soliton models. This paper explores the validity of this treatment. A number of rather general analyses suggest that predictions of exotic baryon properties based on this approximation do not follow from large Nc QCD. These include an analysis of the baryon's width, a comparison of the predictions with general large Nc consistency conditions of the Gervais-Sakita-Dashen-Manohar type; an application of the technique to QCD in the limit where the quarks are heavy; a comparison of this method with the vibration approach of Callan and Klebanov; and the 1/Nc scaling of the excitation energy. It is suggested that the origin of the problem lies in an implicit assumption in the that the collective motion is orthogonal to vibrational motion. While true for non-exotic motion, the Wess-Zumino term induces mixing at leading order between collective and vibrational motion with exotic quantum numbers. This suggests that successful phenomenological predictions of theta+ properties based on rigid-rotor quantization were accidental.
[ { "created": "Mon, 15 Dec 2003 19:04:07 GMT", "version": "v1" }, { "created": "Fri, 9 Jan 2004 13:28:51 GMT", "version": "v2" }, { "created": "Thu, 26 Feb 2004 15:07:26 GMT", "version": "v3" } ]
2009-11-10
[ [ "Cohen", "Thomas D.", "" ] ]
A light collective theta+ baryon state (with strangeness +1) was predicted via rigid-rotor collective quantization of SU(3) chiral soliton models. This paper explores the validity of this treatment. A number of rather general analyses suggest that predictions of exotic baryon properties based on this approximation do not follow from large Nc QCD. These include an analysis of the baryon's width, a comparison of the predictions with general large Nc consistency conditions of the Gervais-Sakita-Dashen-Manohar type; an application of the technique to QCD in the limit where the quarks are heavy; a comparison of this method with the vibration approach of Callan and Klebanov; and the 1/Nc scaling of the excitation energy. It is suggested that the origin of the problem lies in an implicit assumption in the that the collective motion is orthogonal to vibrational motion. While true for non-exotic motion, the Wess-Zumino term induces mixing at leading order between collective and vibrational motion with exotic quantum numbers. This suggests that successful phenomenological predictions of theta+ properties based on rigid-rotor quantization were accidental.
hep-ph/0204342
Hsin-Chia Cheng
Hsin-Chia Cheng, Konstantin T. Matchev, Martin Schmaltz
Radiative Corrections to Kaluza-Klein Masses
33 pages, 13 figures, uses RevTeX4 and axodraw
Phys.Rev.D66:036005,2002
10.1103/PhysRevD.66.036005
EFI-02-73, UFIFT-HEP-02-6, BUHEP-02-20
hep-ph
null
Extra-dimensional theories contain a number of almost degenerate states at each Kaluza-Klein level. If extra dimensional momentum is at least approximately conserved then the phenomenology of such nearly degenerate states depends crucially on the mass splittings between KK modes. We calculate the complete one-loop radiative corrections to KK masses in general 5 and 6 dimensional theories. We apply our formulae to the example of universal extra dimensions and show that the radiative corrections are essential to any meaningful study of the phenomenology. Our calculations demonstrate that Feynman diagrams with loops wrapping the extra dimensions are well-defined and cut-off independent even though higher dimensional theories are not renormalizable.
[ { "created": "Mon, 29 Apr 2002 18:53:20 GMT", "version": "v1" } ]
2009-07-09
[ [ "Cheng", "Hsin-Chia", "" ], [ "Matchev", "Konstantin T.", "" ], [ "Schmaltz", "Martin", "" ] ]
Extra-dimensional theories contain a number of almost degenerate states at each Kaluza-Klein level. If extra dimensional momentum is at least approximately conserved then the phenomenology of such nearly degenerate states depends crucially on the mass splittings between KK modes. We calculate the complete one-loop radiative corrections to KK masses in general 5 and 6 dimensional theories. We apply our formulae to the example of universal extra dimensions and show that the radiative corrections are essential to any meaningful study of the phenomenology. Our calculations demonstrate that Feynman diagrams with loops wrapping the extra dimensions are well-defined and cut-off independent even though higher dimensional theories are not renormalizable.
hep-ph/9802357
Linda M. Stuart
E143 collaboration
Measurements of the Proton and Deuteron Spin Structure Functions g1 and g2
116 pages, 38 tables, 25 figures Submitted to Physical Review D
Phys.Rev.D58:112003,1998
10.1103/PhysRevD.58.112003
SLAC-PUB-7753
hep-ph
null
Measurements are reported of the proton and deuteron spin structure functions g1 at beam energies of 29.1, 16.2, and 9.7 GeV and g2 at a beam energy of 29.1 GeV. The integrals of g1 over x have been evaluated at fixed Q**2 = 3 (GeV/c)**2 using the full data set. The Q**2 dependence of the ratio g1/F1 was studied and found to be small for Q**2 > 1 (GeV/c)**2. Within experimental precision the g2 data are well-described by the Wandzura-Wilczek twist-2 contribution. Twist-3 matrix elements were extracted and compared to theoretical predictions. The asymmetry A2 was measured and found to be significantly smaller than the positivity limit for both proton and deuteron targets. A2 for the proton is found to be positive and inconsistent with zero. Measurements of g1 in the resonance region show strong variations with x and Q**2, consistent with resonant amplitudes extracted from unpolarized data. These data allow us to study the Q**2 dependence of the first moments of g1 below the scaling region.
[ { "created": "Wed, 18 Feb 1998 23:24:26 GMT", "version": "v1" } ]
2012-08-27
[ [ "E143 collaboration", "", "" ] ]
Measurements are reported of the proton and deuteron spin structure functions g1 at beam energies of 29.1, 16.2, and 9.7 GeV and g2 at a beam energy of 29.1 GeV. The integrals of g1 over x have been evaluated at fixed Q**2 = 3 (GeV/c)**2 using the full data set. The Q**2 dependence of the ratio g1/F1 was studied and found to be small for Q**2 > 1 (GeV/c)**2. Within experimental precision the g2 data are well-described by the Wandzura-Wilczek twist-2 contribution. Twist-3 matrix elements were extracted and compared to theoretical predictions. The asymmetry A2 was measured and found to be significantly smaller than the positivity limit for both proton and deuteron targets. A2 for the proton is found to be positive and inconsistent with zero. Measurements of g1 in the resonance region show strong variations with x and Q**2, consistent with resonant amplitudes extracted from unpolarized data. These data allow us to study the Q**2 dependence of the first moments of g1 below the scaling region.
2405.03581
Victor Goncalves
Yuri N. Lima, Andr\'e V. Giannini, Victor P. Goncalves
$D^0$ meson production in $pp$ collisions at large $Q_s^2$
14 pages, 13 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The impact of the non-linear effects in the QCD dynamics on the observables is directly related to the magnitude of the saturation scale $Q_s$, which is predicted to increase with the energy, rapidity and multiplicity. In this paper, we investigate the $D^0$ meson production in $pp$ collisions at forward rapidities and/or high multiplicities considering the Color Glass Condensate (CGC) formalism and the solutions of the running coupling Balitsky - Kovchegov (BK) equation. The contributions of gluon - and charm - initiated processes are taken into account, and a comparison with the current LHCb data is performed. The impact of an intrinsic charm component in the proton's wave function is also estimated. Predictions for the self-normalized yields of $D^0$ mesons as a function of the multiplicity of coproduced charged hadrons are presented, considering $pp$ collisions at $\sqrt{s} = 13$ TeV and different values of the meson rapidity. A comparison with the predictions for the kaon and isolated photon production is performed. Our results indicate that a future experimental analysis of the $D^0$ meson production at forward rapidities and high multiplicities can be useful to probe the CGC formalism and to disentangle the contribution of initial - and final - state effects.
[ { "created": "Mon, 6 May 2024 15:53:41 GMT", "version": "v1" } ]
2024-05-07
[ [ "Lima", "Yuri N.", "" ], [ "Giannini", "André V.", "" ], [ "Goncalves", "Victor P.", "" ] ]
The impact of the non-linear effects in the QCD dynamics on the observables is directly related to the magnitude of the saturation scale $Q_s$, which is predicted to increase with the energy, rapidity and multiplicity. In this paper, we investigate the $D^0$ meson production in $pp$ collisions at forward rapidities and/or high multiplicities considering the Color Glass Condensate (CGC) formalism and the solutions of the running coupling Balitsky - Kovchegov (BK) equation. The contributions of gluon - and charm - initiated processes are taken into account, and a comparison with the current LHCb data is performed. The impact of an intrinsic charm component in the proton's wave function is also estimated. Predictions for the self-normalized yields of $D^0$ mesons as a function of the multiplicity of coproduced charged hadrons are presented, considering $pp$ collisions at $\sqrt{s} = 13$ TeV and different values of the meson rapidity. A comparison with the predictions for the kaon and isolated photon production is performed. Our results indicate that a future experimental analysis of the $D^0$ meson production at forward rapidities and high multiplicities can be useful to probe the CGC formalism and to disentangle the contribution of initial - and final - state effects.
0902.3246
Itay Yavin
Clifford Cheung, Joshua T. Ruderman, Lian-Tao Wang, and Itay Yavin
Kinetic Mixing as the Origin of Light Dark Scales
4 pages, 2 plots, published version, some clarifications added
Phys.Rev.D80:035008,2009
10.1103/PhysRevD.80.035008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a model in which supersymmetric weak scale dark matter is charged under a U(1)_d dark gauge symmetry. Kinetic mixing between U(1)_d and hypercharge generates the appropriate hierarchy of scales needed to explain PAMELA and ATIC with a GeV scale force carrier and DAMA (or INTEGRAL) using the proposals of inelastic (or, respectively, exciting) dark matter. Because of the extreme simplicity of this setup, observational constraints lead to unambiguous determination of the model parameters. In particular, the DAMA scattering cross section is directly related to the size of the hypercharge D-term vacuum expectation value. The known relic abundance of DM can be used to fix the ratio of the dark sector coupling to the dark matter mass. Finally, the recent observation of cosmic ray positron and electron excesses can be used to fix the mass of the dark matter through the observation of a shoulder in the spectrum and the size of the kinetic mixing by fitting to the rate. These parameters can be used to make further predictions, which can be checked at future direct detection, indirect detection, as well as collider experiments.
[ { "created": "Thu, 19 Feb 2009 17:28:17 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2009 03:25:12 GMT", "version": "v2" }, { "created": "Thu, 13 Aug 2009 02:29:44 GMT", "version": "v3" } ]
2009-09-02
[ [ "Cheung", "Clifford", "" ], [ "Ruderman", "Joshua T.", "" ], [ "Wang", "Lian-Tao", "" ], [ "Yavin", "Itay", "" ] ]
We propose a model in which supersymmetric weak scale dark matter is charged under a U(1)_d dark gauge symmetry. Kinetic mixing between U(1)_d and hypercharge generates the appropriate hierarchy of scales needed to explain PAMELA and ATIC with a GeV scale force carrier and DAMA (or INTEGRAL) using the proposals of inelastic (or, respectively, exciting) dark matter. Because of the extreme simplicity of this setup, observational constraints lead to unambiguous determination of the model parameters. In particular, the DAMA scattering cross section is directly related to the size of the hypercharge D-term vacuum expectation value. The known relic abundance of DM can be used to fix the ratio of the dark sector coupling to the dark matter mass. Finally, the recent observation of cosmic ray positron and electron excesses can be used to fix the mass of the dark matter through the observation of a shoulder in the spectrum and the size of the kinetic mixing by fitting to the rate. These parameters can be used to make further predictions, which can be checked at future direct detection, indirect detection, as well as collider experiments.
1002.3631
Yue Zhang
Borut Bajc, Tsedenbaljir Enkhbat, Dilip Kumar Ghosh, Goran Senjanovic, Yue Zhang
MSSM in view of PAMELA and Fermi-LAT
Published version, figures updated
JHEP 1005:048,2010
10.1007/JHEP05(2010)048
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We take the MSSM as a complete theory of low energy phenomena, including neutrino masses and mixings. This immediately implies that the gravitino is the only possible dark matter candidate. We study the implications of the astrophysical experiments such as PAMELA and Fermi-LAT, on this scenario. The theory can account for both the realistic neutrino masses and mixings, and the PAMELA data as long as the slepton masses lie in the $500-10^6 $TeV range. The squarks can be either light or heavy, depending on their contribution to radiative neutrino masses. On the other hand, the Fermi-LAT data imply heavy superpartners, all out of LHC reach, simply on the grounds of the energy scale involved, for the gravitino must weigh more than 2 TeV. The perturbativity of the theory also implies an upper bound on its mass, approximately $6-7 $TeV.
[ { "created": "Fri, 19 Feb 2010 18:14:37 GMT", "version": "v1" }, { "created": "Mon, 21 Jun 2010 10:16:26 GMT", "version": "v2" } ]
2015-03-13
[ [ "Bajc", "Borut", "" ], [ "Enkhbat", "Tsedenbaljir", "" ], [ "Ghosh", "Dilip Kumar", "" ], [ "Senjanovic", "Goran", "" ], [ "Zhang", "Yue", "" ] ]
We take the MSSM as a complete theory of low energy phenomena, including neutrino masses and mixings. This immediately implies that the gravitino is the only possible dark matter candidate. We study the implications of the astrophysical experiments such as PAMELA and Fermi-LAT, on this scenario. The theory can account for both the realistic neutrino masses and mixings, and the PAMELA data as long as the slepton masses lie in the $500-10^6 $TeV range. The squarks can be either light or heavy, depending on their contribution to radiative neutrino masses. On the other hand, the Fermi-LAT data imply heavy superpartners, all out of LHC reach, simply on the grounds of the energy scale involved, for the gravitino must weigh more than 2 TeV. The perturbativity of the theory also implies an upper bound on its mass, approximately $6-7 $TeV.
1312.3017
Keiko Nagao
Keiko I. Nagao
Measuring Dark Matter Distribution in Directional Direct Detection
5pages, 11 figures, to appear in the proceedings of CYGNUS 2013 (CNUM: C13-06-10.6)
null
10.1088/1742-6596/469/1/012009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Direct detection of dark matter with directional sensitivity offers not only measurement of both recoil energy and direction of dark matter, but also a way to understand dark matter distribution in the Galaxy. Maxwell distribution is usually supposed as the distribution near the Earth, however, deviation from that, caused by tidal streams in the Galaxy, has been suggested. We explore the possibility of distinguishing the distribution by direct detection using nuclear emulsions.
[ { "created": "Wed, 11 Dec 2013 01:37:18 GMT", "version": "v1" } ]
2015-06-18
[ [ "Nagao", "Keiko I.", "" ] ]
Direct detection of dark matter with directional sensitivity offers not only measurement of both recoil energy and direction of dark matter, but also a way to understand dark matter distribution in the Galaxy. Maxwell distribution is usually supposed as the distribution near the Earth, however, deviation from that, caused by tidal streams in the Galaxy, has been suggested. We explore the possibility of distinguishing the distribution by direct detection using nuclear emulsions.
hep-ph/0408010
Byung-Yoon Park
Byung-Yoon Park, Hee-Jung Lee, Vicente Vento, Joon-Il Kim, Dong-Pil Min, Mannque Rho
Unified Approach to Dense Matter
6 pages, 4 figures, a talk given at the international conference QCD DOWN UNDER, March 10 - 19, Adelaide, Australia
null
10.1016/j.nuclphysbps.2004.12.040
null
hep-ph nucl-th
null
We apply the Skyrme model to dense hadronic matter, which provides a unified approach to high density, valid in the large Nc limit. In our picture, dense hadronic matter is described by the classical soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.
[ { "created": "Mon, 2 Aug 2004 00:13:23 GMT", "version": "v1" } ]
2009-11-10
[ [ "Park", "Byung-Yoon", "" ], [ "Lee", "Hee-Jung", "" ], [ "Vento", "Vicente", "" ], [ "Kim", "Joon-Il", "" ], [ "Min", "Dong-Pil", "" ], [ "Rho", "Mannque", "" ] ]
We apply the Skyrme model to dense hadronic matter, which provides a unified approach to high density, valid in the large Nc limit. In our picture, dense hadronic matter is described by the classical soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.
hep-ph/9811257
Takeo Moroi
Takeo Moroi
Electric Dipole Moments in Gauge Mediated Models and a Solution to the SUSY CP Problem
13 pages, 2 figures
Phys.Lett. B447 (1999) 75-82
10.1016/S0370-2693(98)01576-7
IASSNS-HEP-98/94
hep-ph
null
The SUSY CP problem in the framework of gauge mediated SUSY breaking model is considered. We first discuss the electric dipole moments of the electron and neutron, which are likely to be larger than the experimental upper bound if all the phases in the Lagrangian are O(1). We derive a constraint on the phases in the so-called $\mu$- and $B_\mu$-parameters and gaugino masses. Then, we discuss a model in which the CP violating phase can be adequately suppressed. If the $\mu$- and $B_\mu$-parameters originate from the same superpotential interaction as the SUSY breaking field, the CP violating phase vanishes. However, in this class of models, the ratio $B_\mu/\mu$ becomes too large, and we discuss a possible scenario to fix this problem.
[ { "created": "Thu, 5 Nov 1998 21:19:56 GMT", "version": "v1" } ]
2009-10-31
[ [ "Moroi", "Takeo", "" ] ]
The SUSY CP problem in the framework of gauge mediated SUSY breaking model is considered. We first discuss the electric dipole moments of the electron and neutron, which are likely to be larger than the experimental upper bound if all the phases in the Lagrangian are O(1). We derive a constraint on the phases in the so-called $\mu$- and $B_\mu$-parameters and gaugino masses. Then, we discuss a model in which the CP violating phase can be adequately suppressed. If the $\mu$- and $B_\mu$-parameters originate from the same superpotential interaction as the SUSY breaking field, the CP violating phase vanishes. However, in this class of models, the ratio $B_\mu/\mu$ becomes too large, and we discuss a possible scenario to fix this problem.
1706.07779
Nejc Ko\v{s}nik
Ilja Dor\v{s}ner, Svjetlana Fajfer, Darius A. Faroughy, Nejc Ko\v{s}nik
The role of the $S_3$ GUT leptoquark in flavor universality and collider searches
Published version. 32 pages, 6 figures
J. High Energ. Phys. (2017) 2017: 188
10.1007/JHEP10(2017)188
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the ability of the $S_3$ scalar leptoquark to address the recent hints of lepton universality violation in $B$ meson decays. The $S_3$ leptoquark with quantum numbers $(\overline{\mathbf{3}},\mathbf{3},1/3)$ naturally emerges in the context of an $SU(5)$ GUT model without any conflict with the stringent limits from observed nucleon stability. Scalar leptoquark $S_3$ with left-handed couplings to 2nd and 3rd generations of charged leptons and down-type quarks seems well-suited to address both $R_{K^{(*)}}$ and $R_{D^{(*)}}$. We quantify this suitability with numerical fits to a plethora of relevant flavor observables. The proposed $SU(5)$ model calls for a second leptoquark state, i.e., $\tilde{R}_2$ with quantum numbers $(\mathbf{3},\mathbf{2},1/6)$, if one is to generate gauge coupling unification and neutrino mass. We accordingly include it in our study to investigate $\tilde{R}_2$'s ability to offset adverse effects of $S_3$ and thus improve a quality of numerical fits. A global fit of the leptoquark Yukawa couplings shows that large couplings of light $S_3$ to $\tau$ leptons are preferred. We furthermore identify $B \to K^{(*)} \bar\nu\nu$ as the most sensitive channel to probe the preferred region of parameter space. Large couplings of $S_3$ to $\tau$ leptons are finally confronted with the experimental searches for $\tau$ final states at the Large Hadron Collider. These searches comprise a study of decay products of the leptoquark pair production, as well as, and more importantly, an analysis of the high-mass $\tau\tau$ final states.
[ { "created": "Fri, 23 Jun 2017 17:02:19 GMT", "version": "v1" }, { "created": "Wed, 20 Sep 2017 12:34:43 GMT", "version": "v2" }, { "created": "Mon, 27 Nov 2017 21:01:32 GMT", "version": "v3" } ]
2017-11-29
[ [ "Doršner", "Ilja", "" ], [ "Fajfer", "Svjetlana", "" ], [ "Faroughy", "Darius A.", "" ], [ "Košnik", "Nejc", "" ] ]
We investigate the ability of the $S_3$ scalar leptoquark to address the recent hints of lepton universality violation in $B$ meson decays. The $S_3$ leptoquark with quantum numbers $(\overline{\mathbf{3}},\mathbf{3},1/3)$ naturally emerges in the context of an $SU(5)$ GUT model without any conflict with the stringent limits from observed nucleon stability. Scalar leptoquark $S_3$ with left-handed couplings to 2nd and 3rd generations of charged leptons and down-type quarks seems well-suited to address both $R_{K^{(*)}}$ and $R_{D^{(*)}}$. We quantify this suitability with numerical fits to a plethora of relevant flavor observables. The proposed $SU(5)$ model calls for a second leptoquark state, i.e., $\tilde{R}_2$ with quantum numbers $(\mathbf{3},\mathbf{2},1/6)$, if one is to generate gauge coupling unification and neutrino mass. We accordingly include it in our study to investigate $\tilde{R}_2$'s ability to offset adverse effects of $S_3$ and thus improve a quality of numerical fits. A global fit of the leptoquark Yukawa couplings shows that large couplings of light $S_3$ to $\tau$ leptons are preferred. We furthermore identify $B \to K^{(*)} \bar\nu\nu$ as the most sensitive channel to probe the preferred region of parameter space. Large couplings of $S_3$ to $\tau$ leptons are finally confronted with the experimental searches for $\tau$ final states at the Large Hadron Collider. These searches comprise a study of decay products of the leptoquark pair production, as well as, and more importantly, an analysis of the high-mass $\tau\tau$ final states.
1711.09803
Harri Niemi
K. J. Eskola, H. Niemi, R. Paatelainen, K. Tuominen
Predictions for multiplicities and flow harmonics in 5.44 TeV Xe+Xe collisions at the CERN Large Hadron Collider
7 pages, 7 figures, revised version. The predicted flow coefficients vn with deformed Xe, and their ratios to 5.023 TeV Pb+Pb vn's are included as ancillary files
Phys. Rev. C 97, 034911 (2018)
10.1103/PhysRevC.97.034911
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the next-to-leading-order event-by-event EKRT model predictions for the centrality dependence of the charged hadron multiplicity in the pseudorapidity interval $|\eta|\le 0.5$, and for the centrality dependence of the charged hadron flow harmonics $v_n\{2\}$ obtained from 2-particle cumulants, in $\sqrt{s_{NN}}=5.44$ TeV Xe+Xe collisions at the CERN Large Hadron Collider. Our prediction for the 0-5 \% central charged multiplicity is $dN_{\rm ch}/d\eta =1218\pm 46$. We also predict $v_n\{2\}$ in Xe+Xe collisions to increase more slowly from central towards peripheral collisions than those in a Pb+Pb system. We find that at $10 \dots 50$\% centralities $v_2\{2\}$ is smaller and $v_3\{2\}$ is larger than in the Pb+Pb system while $v_4\{2\}$ is of the same magnitude in both systems. We also find that the ratio of flow harmonics in Xe+Xe collisions and in Pb+Pb collisions shows a slight sensitivity to the temperature dependence of the shear-viscosity-to-entropy ratio. As we discuss here, the new nuclear mass-number systematics especially in the flow harmonics serves as a welcome further constraint for describing the space-time evolution of a heavy-ion system and for determining the shear viscosity and other transport properties of strongly interacting matter.
[ { "created": "Mon, 27 Nov 2017 16:20:09 GMT", "version": "v1" }, { "created": "Wed, 2 May 2018 14:54:28 GMT", "version": "v2" } ]
2018-05-03
[ [ "Eskola", "K. J.", "" ], [ "Niemi", "H.", "" ], [ "Paatelainen", "R.", "" ], [ "Tuominen", "K.", "" ] ]
We present the next-to-leading-order event-by-event EKRT model predictions for the centrality dependence of the charged hadron multiplicity in the pseudorapidity interval $|\eta|\le 0.5$, and for the centrality dependence of the charged hadron flow harmonics $v_n\{2\}$ obtained from 2-particle cumulants, in $\sqrt{s_{NN}}=5.44$ TeV Xe+Xe collisions at the CERN Large Hadron Collider. Our prediction for the 0-5 \% central charged multiplicity is $dN_{\rm ch}/d\eta =1218\pm 46$. We also predict $v_n\{2\}$ in Xe+Xe collisions to increase more slowly from central towards peripheral collisions than those in a Pb+Pb system. We find that at $10 \dots 50$\% centralities $v_2\{2\}$ is smaller and $v_3\{2\}$ is larger than in the Pb+Pb system while $v_4\{2\}$ is of the same magnitude in both systems. We also find that the ratio of flow harmonics in Xe+Xe collisions and in Pb+Pb collisions shows a slight sensitivity to the temperature dependence of the shear-viscosity-to-entropy ratio. As we discuss here, the new nuclear mass-number systematics especially in the flow harmonics serves as a welcome further constraint for describing the space-time evolution of a heavy-ion system and for determining the shear viscosity and other transport properties of strongly interacting matter.
hep-ph/9905263
Andrei Belitsky
A.V. Belitsky, D. Muller
Scaling violations and off-forward parton distributions: leading order and beyond
3 pages, LaTeX, 3 figures, Talk given at the 7th International Workshop on Deep Inelastic Scattring and QCD, DESY-Zeuthen, April 19-23, 1999
Nucl.Phys.Proc.Suppl. 79 (1999) 573-575
10.1016/S0920-5632(99)00787-2
null
hep-ph
null
We give an outline of a formalism for the solution of the evolution equations for off-forward parton distributions in leading and next-to-leading orders based on partial conformal wave expansion and orthogonal polynomials reconstruction.
[ { "created": "Thu, 6 May 1999 14:00:59 GMT", "version": "v1" } ]
2009-10-31
[ [ "Belitsky", "A. V.", "" ], [ "Muller", "D.", "" ] ]
We give an outline of a formalism for the solution of the evolution equations for off-forward parton distributions in leading and next-to-leading orders based on partial conformal wave expansion and orthogonal polynomials reconstruction.
1511.04449
Alex Gomes Dias
Alexandre Alves, D. A. Camargo, Alex G. Dias
Heavy Higgs Coupled to Vector-like Quarks: Strong CP Problem and Search Prospects at the 14 TeV LHC
21 pages, 8 figures, just a correction in Table I
Phys. Rev. D 94, 015027 (2016)
10.1103/PhysRevD.94.015027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by a solution to the strong CP problem we propose a model where a new heavy neutral CP-even Higgs boson couples to vector-like quarks enhancing its production cross section whose dominant decays are into weak bosons. The masses of the vector-like quarks are generated through interactions with a singlet scalar field charged under a broken global $U(1)$ symmetry providing a solution to the strong CP problem by means of the Peccei-Quinn mechanism. The diboson excess observed by the ATLAS Collaboration is discussed as the new heavy Higgs boson is a candidate to explain a possible signal in this channel. We also show that the 14 TeV LHC is capable of discovering this heavy Higgs with masses up to 1 TeV in the $H\to ZZ\to \ell^+\ell^-\ell^{\prime +}\ell^{\prime -}$ search channel using boosted decision trees to better discriminate between signals and backgrounds and to tame systematic uncertainties in the background rates.
[ { "created": "Fri, 13 Nov 2015 21:00:07 GMT", "version": "v1" }, { "created": "Sat, 23 Jul 2016 23:07:14 GMT", "version": "v2" }, { "created": "Tue, 23 Aug 2016 01:01:10 GMT", "version": "v3" } ]
2016-08-24
[ [ "Alves", "Alexandre", "" ], [ "Camargo", "D. A.", "" ], [ "Dias", "Alex G.", "" ] ]
Motivated by a solution to the strong CP problem we propose a model where a new heavy neutral CP-even Higgs boson couples to vector-like quarks enhancing its production cross section whose dominant decays are into weak bosons. The masses of the vector-like quarks are generated through interactions with a singlet scalar field charged under a broken global $U(1)$ symmetry providing a solution to the strong CP problem by means of the Peccei-Quinn mechanism. The diboson excess observed by the ATLAS Collaboration is discussed as the new heavy Higgs boson is a candidate to explain a possible signal in this channel. We also show that the 14 TeV LHC is capable of discovering this heavy Higgs with masses up to 1 TeV in the $H\to ZZ\to \ell^+\ell^-\ell^{\prime +}\ell^{\prime -}$ search channel using boosted decision trees to better discriminate between signals and backgrounds and to tame systematic uncertainties in the background rates.
hep-ph/0002107
Motohiko Yoshimura
M. Yoshimura
Relic abundance of dark matter particles: new formulation and new result of abundance calculation
7 pages, LATEX file. Talk given at COSMO99
null
10.1142/9789812792129_0004
TU/00/586
hep-ph
null
A new theoretical framework for computation of the relic abundance of cold dark matter particles such as LSP is presented and some generic features of new results are discussed. The most important is a generalization of the Boltzmann equation to include off-shell effects and its thermal average over cosmic medium. It is shown that at very low temperatures, much below the mass of annihilating particles, equilibrium abundance is suppressed only by powers of temperature instead of the exponential Boltzmann factor. This change gives a larger relic abundance when heavy particles freeze out at these low temperatures.
[ { "created": "Thu, 10 Feb 2000 01:33:43 GMT", "version": "v1" } ]
2016-11-03
[ [ "Yoshimura", "M.", "" ] ]
A new theoretical framework for computation of the relic abundance of cold dark matter particles such as LSP is presented and some generic features of new results are discussed. The most important is a generalization of the Boltzmann equation to include off-shell effects and its thermal average over cosmic medium. It is shown that at very low temperatures, much below the mass of annihilating particles, equilibrium abundance is suppressed only by powers of temperature instead of the exponential Boltzmann factor. This change gives a larger relic abundance when heavy particles freeze out at these low temperatures.
1107.4523
Norimi Yokozaki
Masaki Asano, Takeo Moroi, Norimi Yokozaki
Singlet Boson in Supersymmetric Model as a Mimic of the Standard Model Higgs at the LHC
10 pages, 4 figures
null
10.1016/j.physletb.2012.01.043
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the gauge singlet scalar boson in low-energy supersymmetric model may behave as the standard model (SM) Higgs boson if the singlet couples to (heavy) vector-like colored particles. In this case, the SM-Higgs-like signal at the LHC can be mimicked by the singlet production process for wide range of the singlet mass.
[ { "created": "Fri, 22 Jul 2011 14:28:48 GMT", "version": "v1" } ]
2015-05-28
[ [ "Asano", "Masaki", "" ], [ "Moroi", "Takeo", "" ], [ "Yokozaki", "Norimi", "" ] ]
We show that the gauge singlet scalar boson in low-energy supersymmetric model may behave as the standard model (SM) Higgs boson if the singlet couples to (heavy) vector-like colored particles. In this case, the SM-Higgs-like signal at the LHC can be mimicked by the singlet production process for wide range of the singlet mass.
2008.06919
Evangelos Matsinos
Evangelos Matsinos
Determination of the masses and decay widths of the well-established $s$ and $p$ baryon resonances below $2$ GeV
17 pages
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This study appertains to the extraction of estimates for the masses and for the partial decay widths to pion-nucleon final states of the well-established (four-star) $s$ and $p$ baryon resonances below $2$ GeV. These estimates are exclusively obtained from the data contained in the recent compilation by the Particle Data Group. Only the $N$ ($S=0,I=1/2$) and the $\Delta$ ($S=0,I=3/2$) states are considered, where $S$ and $I$ denote strangeness and total isospin, respectively.
[ { "created": "Sun, 16 Aug 2020 14:34:04 GMT", "version": "v1" } ]
2020-08-18
[ [ "Matsinos", "Evangelos", "" ] ]
This study appertains to the extraction of estimates for the masses and for the partial decay widths to pion-nucleon final states of the well-established (four-star) $s$ and $p$ baryon resonances below $2$ GeV. These estimates are exclusively obtained from the data contained in the recent compilation by the Particle Data Group. Only the $N$ ($S=0,I=1/2$) and the $\Delta$ ($S=0,I=3/2$) states are considered, where $S$ and $I$ denote strangeness and total isospin, respectively.
hep-ph/0605039
Alakabha Datta
Alakabha Datta
$B_s$ Mixing and New Physics in hadronic $b \to s \bar{q} q$ transitions
19 pages, no figures, references added, text added, accepted for publication
Phys.Rev.D74:014022,2006
10.1103/PhysRevD.74.014022
null
hep-ph
null
We study the implication of the recent $\Delta m_s$ measurement on $ b \to s \bar{q} q$ transitions. We show that it is possible, in the presence of a flavour symmetry, that the phase in $B_s$ mixing may be unobservable even with new CP odd phases in $b \to s$ transitions. These phases may then produce new CP odd effects in certain $b \to s \bar{q} q $ transitions like $ B \to K \pi$ but not in others like $ B_d \to \phi K_s$. Working in a two higgs doublet model of new physics we discuss the allowed NP contribution to $B \to K \pi$ and $ B_d \to \phi K_s$ decays with the new $ Delta m_s$ measurement.
[ { "created": "Thu, 4 May 2006 01:24:55 GMT", "version": "v1" }, { "created": "Wed, 10 May 2006 22:00:20 GMT", "version": "v2" }, { "created": "Thu, 13 Jul 2006 20:36:14 GMT", "version": "v3" } ]
2008-11-26
[ [ "Datta", "Alakabha", "" ] ]
We study the implication of the recent $\Delta m_s$ measurement on $ b \to s \bar{q} q$ transitions. We show that it is possible, in the presence of a flavour symmetry, that the phase in $B_s$ mixing may be unobservable even with new CP odd phases in $b \to s$ transitions. These phases may then produce new CP odd effects in certain $b \to s \bar{q} q $ transitions like $ B \to K \pi$ but not in others like $ B_d \to \phi K_s$. Working in a two higgs doublet model of new physics we discuss the allowed NP contribution to $B \to K \pi$ and $ B_d \to \phi K_s$ decays with the new $ Delta m_s$ measurement.
2305.08032
Xun-Jie Xu
Xun-Jie Xu
Neutrino forces and experimental probes
6 pages, 4 figures, Contribution to the 2023 Electroweak session of the 57th Rencontres de Moriond
null
null
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/4.0/
Neutrinos as almost massless particles could mediate long-range forces, known as neutrino forces. In this talk, I will introduce some theoretical aspects of neutrino forces, including why the potential of a neutrino force has the $1/r^{5}$ form and how it may vary under different circumstances. Experimental probes and possible implications for cosmology are also briefly discussed.
[ { "created": "Sun, 14 May 2023 00:27:52 GMT", "version": "v1" } ]
2023-05-16
[ [ "Xu", "Xun-Jie", "" ] ]
Neutrinos as almost massless particles could mediate long-range forces, known as neutrino forces. In this talk, I will introduce some theoretical aspects of neutrino forces, including why the potential of a neutrino force has the $1/r^{5}$ form and how it may vary under different circumstances. Experimental probes and possible implications for cosmology are also briefly discussed.
hep-ph/0112205
Joseph Schechter
Joseph Schechter
Introduction to effective Lagrangians for QCD
12 pages, 2 figures, talk at "Compact stars in the QCD phase diagram", Copenhagen, Aug. 15-18, 2001
eConf C010815 (2002) 76-87
null
SU-4252-750
hep-ph
null
A brief introduction to the effective Lagrangian treatment of QCD (in the sense of using fields representing physical particles rather than quarks and gluons) will be given. The historical evolution of the subject will be discussed. Some background material related to a recent model for Gamma Ray Bursters will be given. Finally, some recent work on low energy strong interactions will be mentioned.
[ { "created": "Fri, 14 Dec 2001 18:45:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schechter", "Joseph", "" ] ]
A brief introduction to the effective Lagrangian treatment of QCD (in the sense of using fields representing physical particles rather than quarks and gluons) will be given. The historical evolution of the subject will be discussed. Some background material related to a recent model for Gamma Ray Bursters will be given. Finally, some recent work on low energy strong interactions will be mentioned.
0811.4620
Ruben Flores
C. Juarez-Leon, A. Martinez, M. Neri, J.J. Torres, Ruben Flores-Mendieta, A. Garcia
Radiative corrections to the three-body region of the Dalitz plot of baryon semileptonic decays with angular correlation between polarized emitted baryons and charged leptons: The initial-baryon rest frame case
7 pages, Revtex4, no figures
Phys.Rev.D79:057502,2009
10.1103/PhysRevD.79.057502
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We complement the results for the radiative corrections to the s2.l angular correlation of baryon semileptonic decays of Ref. [1] with the final results in the rest frame of the decaying baryon.
[ { "created": "Thu, 27 Nov 2008 21:35:16 GMT", "version": "v1" } ]
2009-03-24
[ [ "Juarez-Leon", "C.", "" ], [ "Martinez", "A.", "" ], [ "Neri", "M.", "" ], [ "Torres", "J. J.", "" ], [ "Flores-Mendieta", "Ruben", "" ], [ "Garcia", "A.", "" ] ]
We complement the results for the radiative corrections to the s2.l angular correlation of baryon semileptonic decays of Ref. [1] with the final results in the rest frame of the decaying baryon.
1211.0118
Shivani Gupta
Monojit Ghosh, Srubabati Goswami, Shivani Gupta
Two Zero Mass Matrices and Sterile Neutrinos
20 pages, 5 figures
null
10.1007/JHEP04(2013)103
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent experimental data is indicative of the existence of sterile neutrinos. The minimal scheme that can account for the data and is consistent with cosmological observations is the 3+1 picture which consists of three predominantly active and one predominantly sterile neutrino with the fourth neutrino being heavier than the other three. Within this scheme there are two possibilities depending on whether the three light states obey normal or inverted hierarchy. In this paper we consider the two zero textures of the low energy neutrino mass matrix in presence of one additional sterile neutrino. We find that among 45 possible two zero textures for this case, 15 are consistent with all current observations. Remarkably, these correspond to the two-zero textures of a three active neutrino mass matrix. We discuss the mass spectrum and the parameter correlations that we find in the various textures. We also present the effective mass governing neutrinoless double beta decay as a function of the lowest mass.
[ { "created": "Thu, 1 Nov 2012 08:36:56 GMT", "version": "v1" } ]
2015-06-12
[ [ "Ghosh", "Monojit", "" ], [ "Goswami", "Srubabati", "" ], [ "Gupta", "Shivani", "" ] ]
Recent experimental data is indicative of the existence of sterile neutrinos. The minimal scheme that can account for the data and is consistent with cosmological observations is the 3+1 picture which consists of three predominantly active and one predominantly sterile neutrino with the fourth neutrino being heavier than the other three. Within this scheme there are two possibilities depending on whether the three light states obey normal or inverted hierarchy. In this paper we consider the two zero textures of the low energy neutrino mass matrix in presence of one additional sterile neutrino. We find that among 45 possible two zero textures for this case, 15 are consistent with all current observations. Remarkably, these correspond to the two-zero textures of a three active neutrino mass matrix. We discuss the mass spectrum and the parameter correlations that we find in the various textures. We also present the effective mass governing neutrinoless double beta decay as a function of the lowest mass.
hep-ph/9807444
Agaev Shahin Sabir
S.S.Agaev
Light Mesons elm Form Factor and Running Coupling Effects
10 pages, 2 figures. Talk given at the Euroconference QCD98, Montpellier 2-8th July 1998, France; to appear in Proceedings
Nucl.Phys.Proc.Suppl. 74 (1999) 155-158
10.1016/S0920-5632(99)00153-X
null
hep-ph
null
The pion and kaon electromagnetic form factors $F_{M}(Q^2)$ are calculated at the leading order of pQCD using the running coupling constant method. In computations dependence of the meson distribution amplitudes on the hard scale $Q^2$ is taken into account. The Borel transform and resummed expression for $F_{M}(Q^2)$ are found. The effect of the next-to-leading order term in expansion of $\alpha_{S}(\lambda Q^2)$ in terms of $\alpha_{S}(Q^2)$ on the pion form factor $F_{\pi}(Q^2)$ is discussed, comparison is made with the infrared matching scheme's result.
[ { "created": "Tue, 21 Jul 1998 12:58:18 GMT", "version": "v1" } ]
2009-10-31
[ [ "Agaev", "S. S.", "" ] ]
The pion and kaon electromagnetic form factors $F_{M}(Q^2)$ are calculated at the leading order of pQCD using the running coupling constant method. In computations dependence of the meson distribution amplitudes on the hard scale $Q^2$ is taken into account. The Borel transform and resummed expression for $F_{M}(Q^2)$ are found. The effect of the next-to-leading order term in expansion of $\alpha_{S}(\lambda Q^2)$ in terms of $\alpha_{S}(Q^2)$ on the pion form factor $F_{\pi}(Q^2)$ is discussed, comparison is made with the infrared matching scheme's result.
hep-ph/9710411
Anatoli Efremov
A.V. Efremov (JINR, Dubna, Russia)
Nuclear Structure Functions and Cumulative Processes
Latex file 9 pages 5 eps figures, wrapfig.sty. An updated version of the talk at 13 International Seminar on Relativistic Nuclear Physics and QCD (Dubna, Sept. 2-7, 1996) which includes new experimental data and some ideas appeared since that time. Will appear in the Proceedings
null
null
null
hep-ph
null
The authors's point of view, based on QCD, on the nuclear quark structure is presented. Different models for explaining the EMC--effect are considered. It is also shown that cumulative production data are very useful for a better understanding of the EMC--effect and give some evidence in favor of its multiquark nature.
[ { "created": "Mon, 20 Oct 1997 14:21:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Efremov", "A. V.", "", "JINR, Dubna, Russia" ] ]
The authors's point of view, based on QCD, on the nuclear quark structure is presented. Different models for explaining the EMC--effect are considered. It is also shown that cumulative production data are very useful for a better understanding of the EMC--effect and give some evidence in favor of its multiquark nature.
hep-ph/0007309
John R. Hiller
J.R. Hiller (University of Minnesota Duluth)
Calculations with DLCQ
7 pages; LaTeX2e, elsart.cls; to appear in the proceedings of the Tenth International Light-Cone Meeting on Nonperturbative QCD and Hadron Phenomenology, Heidelberg, June 12-17, 2000
Nucl.Phys.Proc.Suppl. 90 (2000) 170-174
10.1016/S0920-5632(00)00891-4
UMN-D-00-5
hep-ph
null
The method of discrete light-cone quantization (DLCQ) and useful refinements are summarized. Applications to various field theories are reviewed.
[ { "created": "Wed, 26 Jul 2000 22:38:00 GMT", "version": "v1" } ]
2009-10-31
[ [ "Hiller", "J. R.", "", "University of Minnesota Duluth" ] ]
The method of discrete light-cone quantization (DLCQ) and useful refinements are summarized. Applications to various field theories are reviewed.
1205.6320
Kazem Azizi
T. M. Aliev, K. Azizi, M. Savci
Mixing angle of doubly heavy baryons in QCD
6 Pages
null
10.1016/j.physletb.2012.07.033
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the mixing angles between the spin--1/2, $\Xi_{bc}$--$\Xi^\prime_{bc}$ and $\Omega_{bc}$--$\Omega^\prime_{bc}$ states of doubly heavy baryons within the QCD sum rules method. It is found that the mixing angles are large and have the values $\varphi_{\Xi_{bc}} = 16^0 \pm 5^0$ and $\varphi_{\Omega_{bc}} = 18^0 \pm 6^0$, respectively. The mixing angles are slightly smaller compared to the predictions of the non--relativistic quark model, $\varphi_{\Xi_{bc}} = 25.5^0$ and $\varphi_{\Omega_{bc}} = 25.9^0$.
[ { "created": "Tue, 29 May 2012 10:15:45 GMT", "version": "v1" }, { "created": "Sat, 14 Jul 2012 11:56:05 GMT", "version": "v2" } ]
2015-06-05
[ [ "Aliev", "T. M.", "" ], [ "Azizi", "K.", "" ], [ "Savci", "M.", "" ] ]
We calculate the mixing angles between the spin--1/2, $\Xi_{bc}$--$\Xi^\prime_{bc}$ and $\Omega_{bc}$--$\Omega^\prime_{bc}$ states of doubly heavy baryons within the QCD sum rules method. It is found that the mixing angles are large and have the values $\varphi_{\Xi_{bc}} = 16^0 \pm 5^0$ and $\varphi_{\Omega_{bc}} = 18^0 \pm 6^0$, respectively. The mixing angles are slightly smaller compared to the predictions of the non--relativistic quark model, $\varphi_{\Xi_{bc}} = 25.5^0$ and $\varphi_{\Omega_{bc}} = 25.9^0$.
2311.09315
Marco Gorghetto
Marco Gorghetto, Edward Hardy, Horia Nicolaescu, Alessio Notari, Michele Redi
Early vs late string networks from a minimal QCD Axion
31 pages + appendices
null
null
null
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We propose a new regime of minimal QCD axion dark matter that lies between the pre- and post-inflationary scenarios, such that the Peccei-Quinn (PQ) symmetry is restored only on sufficiently large spatial scales. This leads to a novel cosmological evolution, in which strings and domain walls re-enter the horizon and annihilate later than in the ordinary post-inflationary regime, possibly even after the QCD crossover. Such dynamics can occur if the PQ symmetry is restored by inflationary fluctuations, i.e. the Hubble parameter during inflation $H_I$ is larger than the PQ breaking scale $f_a$, but it is not thermally restored afterwards. Solving the Fokker-Planck equation, we estimate the number of inflationary e-folds required for the PQ symmetry to be, on average, restored. Moreover, we show that, in the large parts of parameter space where the radial mode is displaced from the minimum by de Sitter fluctuations, a string network forms due to the radial mode oscillating over the top of its potential after inflation. In both cases we identify order one ranges in $H_I/f_a$ and in the quartic coupling $\lambda$ of the PQ potential that lead to the late-string dynamics. In this regime the cosmological dark matter abundance can be reproduced for axion decay constants as low as the astrophysical constraint $O(10^8)$ GeV, corresponding to axion masses up to $10^{-2}~{\rm eV}$, and with miniclusters with masses as large as $O(10)M_\odot$.
[ { "created": "Wed, 15 Nov 2023 19:15:20 GMT", "version": "v1" }, { "created": "Tue, 16 Jan 2024 13:15:52 GMT", "version": "v2" } ]
2024-01-17
[ [ "Gorghetto", "Marco", "" ], [ "Hardy", "Edward", "" ], [ "Nicolaescu", "Horia", "" ], [ "Notari", "Alessio", "" ], [ "Redi", "Michele", "" ] ]
We propose a new regime of minimal QCD axion dark matter that lies between the pre- and post-inflationary scenarios, such that the Peccei-Quinn (PQ) symmetry is restored only on sufficiently large spatial scales. This leads to a novel cosmological evolution, in which strings and domain walls re-enter the horizon and annihilate later than in the ordinary post-inflationary regime, possibly even after the QCD crossover. Such dynamics can occur if the PQ symmetry is restored by inflationary fluctuations, i.e. the Hubble parameter during inflation $H_I$ is larger than the PQ breaking scale $f_a$, but it is not thermally restored afterwards. Solving the Fokker-Planck equation, we estimate the number of inflationary e-folds required for the PQ symmetry to be, on average, restored. Moreover, we show that, in the large parts of parameter space where the radial mode is displaced from the minimum by de Sitter fluctuations, a string network forms due to the radial mode oscillating over the top of its potential after inflation. In both cases we identify order one ranges in $H_I/f_a$ and in the quartic coupling $\lambda$ of the PQ potential that lead to the late-string dynamics. In this regime the cosmological dark matter abundance can be reproduced for axion decay constants as low as the astrophysical constraint $O(10^8)$ GeV, corresponding to axion masses up to $10^{-2}~{\rm eV}$, and with miniclusters with masses as large as $O(10)M_\odot$.
1201.4101
Micha{\l} Ochman
Jacek Holeczek, Michal Ochman, Elzbieta Stephan, Marek Zralek
Physics Beyond Standard Model in Neutron Beta Decay
6 pages, 6 figures, presented at the XXXV International Conference of Theoretical Physics "Matter to the Deepest 2011", Ustron, Poland, September 12-18, 2011
Acta Phys.Polon.B42:2493-2499,2011
10.5506/APhysPolB.42.2493
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Limits from neutron beta decay on parameters describing physics beyond the Standard Model are presented. New Physics is described by the most general Lorentz invariant effective Hamiltonian involving vector, scalar and tensor operators and Standard Model fields only. Two-parameter fits to the decay parameters measured in free neutron beta decay have been done, in some cases indicating rather big dependence of the results on g_A/g_V ratio of nucleon form factors at zero four-momentum transfer.
[ { "created": "Thu, 19 Jan 2012 16:41:06 GMT", "version": "v1" } ]
2012-01-20
[ [ "Holeczek", "Jacek", "" ], [ "Ochman", "Michal", "" ], [ "Stephan", "Elzbieta", "" ], [ "Zralek", "Marek", "" ] ]
Limits from neutron beta decay on parameters describing physics beyond the Standard Model are presented. New Physics is described by the most general Lorentz invariant effective Hamiltonian involving vector, scalar and tensor operators and Standard Model fields only. Two-parameter fits to the decay parameters measured in free neutron beta decay have been done, in some cases indicating rather big dependence of the results on g_A/g_V ratio of nucleon form factors at zero four-momentum transfer.
1101.4148
Yu-Feng Zhou
Ze-Peng Liu, Yue-Liang Wu and Yu-Feng Zhou
Enhancement of dark matter relic density from the late time dark matter conversions
15 pages, 3 figures, version to appear in Eur.Phys.J.C
Eur.Phys.J.C71:1749,2011
10.1140/epjc/s10052-011-1749-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate that if the dark matter (DM) in the Universe contains multiple components,the interactions between the DM components may induce DM conversions. It is then possible that the lightest DM component with an annihilation cross section much larger than that of the typical weakly interacting massive particle (WIMP) can obtain a relic density in consistent with the cosmological observations, due to an enhancement from the DM conversion process at late time after the thermal decoupling. This provides an alternative source of large boost factor required to explain the excesses reported by the recent DM indirect search experiments.
[ { "created": "Fri, 21 Jan 2011 14:44:21 GMT", "version": "v1" }, { "created": "Tue, 1 Feb 2011 08:26:52 GMT", "version": "v2" }, { "created": "Fri, 9 Sep 2011 12:15:21 GMT", "version": "v3" } ]
2011-10-11
[ [ "Liu", "Ze-Peng", "" ], [ "Wu", "Yue-Liang", "" ], [ "Zhou", "Yu-Feng", "" ] ]
We demonstrate that if the dark matter (DM) in the Universe contains multiple components,the interactions between the DM components may induce DM conversions. It is then possible that the lightest DM component with an annihilation cross section much larger than that of the typical weakly interacting massive particle (WIMP) can obtain a relic density in consistent with the cosmological observations, due to an enhancement from the DM conversion process at late time after the thermal decoupling. This provides an alternative source of large boost factor required to explain the excesses reported by the recent DM indirect search experiments.
1404.4564
Adam Alloul
Adam Alloul
Top-down and bottom-up excursions beyond the Standard Model: The example of left-right symmetries in supersymmetry
Ph.D thesis defended at IPHC (France) on september 20th 2013, 168 pages
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this Ph.D thesis three main projects are presented. In the first one the phenomenology associated with the neutralinos and charginos sector of the left-right symmetric supersymmetric model is explored. After a detailed motivation of the study and construction of such models, it is shown that these models can be easily discovered in multi-leptonic final states as they lead to signatures very different from those induced by the Standard Model or its supersymmetric version. In the second project, we concentrate on the phenomenology associated with doubly-charged particles. Starting from the hypothesis that such a particle is discovered at the LHC, we build several effective field theories depending on both the representation under SU(2)_L to which they belong the particle and their spin and perform a Monte Carlo analysis highlighting some key observables that would help to determine their quantum numbers. Another part of my thesis, complementary to the phenomenology work, has consisted in developping computer programs that might be helpful for phenomenological studies. Working in the framework of the Mathematica package FeynRules, I took part in the development of a routine able to extract automatically the analytical expressions of the renormalization group equations at the two-loop level for any renormalizable supersymmetric model. I have also been involved in the development of another module of FeynRules able to extract automatically the analytical expressions for the mass matrices associated to any model implemented in FeynRules and to export these equations in the form of a C++ source code able to diagonalize the matrices and store the mixing matrices as well as the spectrum in an SLHA-compliant file.
[ { "created": "Thu, 17 Apr 2014 15:52:20 GMT", "version": "v1" } ]
2014-04-18
[ [ "Alloul", "Adam", "" ] ]
In this Ph.D thesis three main projects are presented. In the first one the phenomenology associated with the neutralinos and charginos sector of the left-right symmetric supersymmetric model is explored. After a detailed motivation of the study and construction of such models, it is shown that these models can be easily discovered in multi-leptonic final states as they lead to signatures very different from those induced by the Standard Model or its supersymmetric version. In the second project, we concentrate on the phenomenology associated with doubly-charged particles. Starting from the hypothesis that such a particle is discovered at the LHC, we build several effective field theories depending on both the representation under SU(2)_L to which they belong the particle and their spin and perform a Monte Carlo analysis highlighting some key observables that would help to determine their quantum numbers. Another part of my thesis, complementary to the phenomenology work, has consisted in developping computer programs that might be helpful for phenomenological studies. Working in the framework of the Mathematica package FeynRules, I took part in the development of a routine able to extract automatically the analytical expressions of the renormalization group equations at the two-loop level for any renormalizable supersymmetric model. I have also been involved in the development of another module of FeynRules able to extract automatically the analytical expressions for the mass matrices associated to any model implemented in FeynRules and to export these equations in the form of a C++ source code able to diagonalize the matrices and store the mixing matrices as well as the spectrum in an SLHA-compliant file.
1612.01937
Dieter M\"uller
G. Duplan\v{c}i\'c and D. M\"uller and K. Passek-Kumeri\v{c}ki
Next-to-leading order corrections to deeply virtual production of pseudoscalar mesons
13 pages, 2 figures
null
10.1016/j.physletb.2017.05.097
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We complete the perturbative next-to-leading order corrections to the hard scattering amplitudes of deeply virtual meson leptoproduction processes at leading twist-two level by presenting the results for the production of flavor singlet pseudoscalar mesons. The new results are given in the common momentum fraction representation and in terms of conformal moments. We also comment on the flavor singlet results for deeply virtual vector meson production.
[ { "created": "Tue, 6 Dec 2016 18:16:39 GMT", "version": "v1" } ]
2017-06-14
[ [ "Duplančić", "G.", "" ], [ "Müller", "D.", "" ], [ "Passek-Kumerički", "K.", "" ] ]
We complete the perturbative next-to-leading order corrections to the hard scattering amplitudes of deeply virtual meson leptoproduction processes at leading twist-two level by presenting the results for the production of flavor singlet pseudoscalar mesons. The new results are given in the common momentum fraction representation and in terms of conformal moments. We also comment on the flavor singlet results for deeply virtual vector meson production.
2006.16931
Xiao-Gang He
Jin Sun, Xiao-Gang He
DFSZ Axion Couplings Revisited
Title modified and materials added. Version to appear in PLB
null
10.1016/j.physletb.2020.135881
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Among many possibilities, solar axion has been proposed to explain the electronic recoil events excess observed by Xenon1T collaboration, although it has tension with astrophysical observations. The axion couplings, to photon $g_{a\gamma}$ and to electron $g_{ae}$ play important roles. These couplings are related to the Peccei-Quinn (PQ) charges $X_f$ for fermions. In most of the calculations, $g_{a\gamma}$ is obtained by normalizing to the ratio of electromagnetic anomaly factor $E = TrX_f Q^2_f N_c$ ($N_c$ is 3 and 1 for quarks and charged leptons respectively) and QCD anomaly factor $N = TrX_q T(q)$ ($T(q)$ is quarks' $SU(3)_c$ index). The broken PQ symmetry generator is used in the calculation which does not seem to extract out the components of broken generator in the axion which are "eaten" by the $Z$ boson. However, using the physical components of axion or the ratio of anomaly factors should obtain the same results in the DFSZ for $g_{a\gamma}$. When going beyond the standard DFSZ models, such as variant DFSZ models, where more Higgs doublets and fermions have different PQ charges, one may wonder if the results are different. We show that the two methods obtain the same results as expected, but the axion couplings to quarks and leptons $g_{af}$ (here f indicates one of the fermions in the SM) are more conveniently calculated in the physical axion basis. The result depends on the values of the vacuum expectation values leading to a wider parameter space for $g_{af}$ in beyond the standard DFSZ axion. We also show explicitly how flavor conserving $g_{af}$ couplings can be maintained when there are more than one Higgs doublets couple to the up and down fermion sectors in variant DFSZ models at tree level, and how flavor violating couplings can arise.
[ { "created": "Tue, 30 Jun 2020 16:01:28 GMT", "version": "v1" }, { "created": "Sun, 5 Jul 2020 08:37:42 GMT", "version": "v2" }, { "created": "Sat, 25 Jul 2020 12:12:52 GMT", "version": "v3" }, { "created": "Tue, 20 Oct 2020 06:03:32 GMT", "version": "v4" } ]
2020-11-04
[ [ "Sun", "Jin", "" ], [ "He", "Xiao-Gang", "" ] ]
Among many possibilities, solar axion has been proposed to explain the electronic recoil events excess observed by Xenon1T collaboration, although it has tension with astrophysical observations. The axion couplings, to photon $g_{a\gamma}$ and to electron $g_{ae}$ play important roles. These couplings are related to the Peccei-Quinn (PQ) charges $X_f$ for fermions. In most of the calculations, $g_{a\gamma}$ is obtained by normalizing to the ratio of electromagnetic anomaly factor $E = TrX_f Q^2_f N_c$ ($N_c$ is 3 and 1 for quarks and charged leptons respectively) and QCD anomaly factor $N = TrX_q T(q)$ ($T(q)$ is quarks' $SU(3)_c$ index). The broken PQ symmetry generator is used in the calculation which does not seem to extract out the components of broken generator in the axion which are "eaten" by the $Z$ boson. However, using the physical components of axion or the ratio of anomaly factors should obtain the same results in the DFSZ for $g_{a\gamma}$. When going beyond the standard DFSZ models, such as variant DFSZ models, where more Higgs doublets and fermions have different PQ charges, one may wonder if the results are different. We show that the two methods obtain the same results as expected, but the axion couplings to quarks and leptons $g_{af}$ (here f indicates one of the fermions in the SM) are more conveniently calculated in the physical axion basis. The result depends on the values of the vacuum expectation values leading to a wider parameter space for $g_{af}$ in beyond the standard DFSZ axion. We also show explicitly how flavor conserving $g_{af}$ couplings can be maintained when there are more than one Higgs doublets couple to the up and down fermion sectors in variant DFSZ models at tree level, and how flavor violating couplings can arise.
1005.0617
Timothy Dulaney
Timothy R. Dulaney (1), Pavel Fileviez Perez (2) and Mark B. Wise (1) ((1) Caltech, (2) Wisconsin U., Madison)
Dark Matter, Baryon Asymmetry, and Spontaneous B and L Breaking
23 pages, 5 figures; revised version, typos removed, references added, discussion expanded
Phys.Rev.D83:023520,2011
10.1103/PhysRevD.83.023520
CALT 68-2788
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the dark matter and the cosmological baryon asymmetry in a simple theory where baryon (B) and lepton (L) number are local gauge symmetries that are spontaneously broken. In this model, the cold dark matter candidate is the lightest new field with baryon number and its stability is an automatic consequence of the gauge symmetry. Dark matter annihilation is either through a leptophobic gauge boson whose mass must be below a TeV or through the Higgs boson. Since the mass of the leptophobic gauge boson has to be below the TeV scale one finds that in the first scenario there is a lower bound on the elastic cross section of about 5x10^{-46} cm^2. Even though baryon number is gauged and not spontaneously broken until the weak scale, a cosmologically acceptable baryon excess is possible. There is tension between achieving both the measured baryon excess and the dark matter density.
[ { "created": "Tue, 4 May 2010 20:00:01 GMT", "version": "v1" }, { "created": "Tue, 11 May 2010 17:02:06 GMT", "version": "v2" }, { "created": "Thu, 24 Jun 2010 17:48:55 GMT", "version": "v3" }, { "created": "Wed, 29 Sep 2010 22:04:43 GMT", "version": "v4" } ]
2015-03-17
[ [ "Dulaney", "Timothy R.", "", "Caltech" ], [ "Perez", "Pavel Fileviez", "", "Wisconsin U., Madison" ], [ "Wise", "Mark B.", "", "Caltech" ] ]
We investigate the dark matter and the cosmological baryon asymmetry in a simple theory where baryon (B) and lepton (L) number are local gauge symmetries that are spontaneously broken. In this model, the cold dark matter candidate is the lightest new field with baryon number and its stability is an automatic consequence of the gauge symmetry. Dark matter annihilation is either through a leptophobic gauge boson whose mass must be below a TeV or through the Higgs boson. Since the mass of the leptophobic gauge boson has to be below the TeV scale one finds that in the first scenario there is a lower bound on the elastic cross section of about 5x10^{-46} cm^2. Even though baryon number is gauged and not spontaneously broken until the weak scale, a cosmologically acceptable baryon excess is possible. There is tension between achieving both the measured baryon excess and the dark matter density.
1307.6499
Antonio Enrique C\'arcamo Hern\'andez acarcamo
A. E. C\'arcamo Hern\'andez, Ivo de Medeiros Varzielas, S.G. Kovalenko, H. P\"as, Iv\'an Schmidt
Lepton masses and mixings in a $A_{4}$ multi-Higgs model with radiative seesaw mechanism
15 pages, 1 figure; acknowledgements modified. Version for publication in Physical Review D
Phys. Rev. D 88, 076014 (2013)
10.1103/PhysRevD.88.076014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a renormalizable multi-Higgs model with $A_{4}\otimes Z_{2}\otimes Z^{\prime}_{2}$ symmetry, accounting for the experimental deviation from the tribimaximal mixing pattern of the neutrino mixing matrix. In this framework we study the charged lepton and neutrino masses and mixings. The light neutrino masses are generated via a radiative seesaw mechanism, which involves a single heavy Majorana neutrino and neutral scalars running in the loops. The obtained neutrino mixings and mass squared splittings are in good agreement with the neutrino oscillation experimental data for both normal and inverted hierarchy. The model predicts an effective Majorana neutrino mass $m_{\beta\beta}=$ 4 meV and 50 meV for the normal and the inverted neutrino spectrum, respectively. The model also features a suppression of CP violation in neutrino oscillations, a low scale for the heavy Majorana neutrino (few TeV) and, due to the unbroken $Z_2$ symmetry, a natural dark matter candidate.
[ { "created": "Wed, 24 Jul 2013 17:23:14 GMT", "version": "v1" }, { "created": "Wed, 16 Oct 2013 17:47:54 GMT", "version": "v2" }, { "created": "Mon, 21 Oct 2013 15:17:51 GMT", "version": "v3" } ]
2013-11-13
[ [ "Hernández", "A. E. Cárcamo", "" ], [ "Varzielas", "Ivo de Medeiros", "" ], [ "Kovalenko", "S. G.", "" ], [ "Päs", "H.", "" ], [ "Schmidt", "Iván", "" ] ]
We propose a renormalizable multi-Higgs model with $A_{4}\otimes Z_{2}\otimes Z^{\prime}_{2}$ symmetry, accounting for the experimental deviation from the tribimaximal mixing pattern of the neutrino mixing matrix. In this framework we study the charged lepton and neutrino masses and mixings. The light neutrino masses are generated via a radiative seesaw mechanism, which involves a single heavy Majorana neutrino and neutral scalars running in the loops. The obtained neutrino mixings and mass squared splittings are in good agreement with the neutrino oscillation experimental data for both normal and inverted hierarchy. The model predicts an effective Majorana neutrino mass $m_{\beta\beta}=$ 4 meV and 50 meV for the normal and the inverted neutrino spectrum, respectively. The model also features a suppression of CP violation in neutrino oscillations, a low scale for the heavy Majorana neutrino (few TeV) and, due to the unbroken $Z_2$ symmetry, a natural dark matter candidate.
2303.05409
Jonathan Ronca
J. Baglio, F. Campanario, S. Glaus, M. M\"uhlleitner, J. Ronca and M. Spira
Full NLO QCD predictions for Higgs-pair production in the 2-Higgs-Doublet Model
13 pages, 10 figures. V2: minor typos corrected, identical to published version
Eur. Phys. J. C 83, 9, 826 (2023)
10.1140/epjc/s10052-023-11957-2
CERN-TH-2022-108, IFIC/23-08, KA-TP-02-2023, P3H-23-013, PSI-PR-23-6
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After the discovery of the Higgs boson in 2012 at the CERN Large Hadron Collider (LHC), the study of its properties still leaves room for an extended Higgs sector with more than one Higgs boson. 2-Higgs Doublet Models (2HDMs) are well-motivated extensions of the Standard Model (SM) with five physical Higgs bosons: two CP-even states $h$ and $H$, one CP-odd state $A$, and two charged states $H^\pm_{}$. In this letter, we present the calculation of the full next-to-leading order (NLO) QCD corrections to $hH$ and $AA$ production at the LHC in the 2HDM at small values of the ratio of the vacuum expectation values, $\tan\beta$, including the exact top-mass dependence everywhere in the calculation. Using techniques applied in the NLO QCD SM Higgs pair production calculation, we present results for the total cross section as well as for the invariant Higgs-pair-mass distribution at the LHC. We also provide the top-quark scale and scheme uncertainties which are found to be sizeable.
[ { "created": "Thu, 9 Mar 2023 16:53:04 GMT", "version": "v1" }, { "created": "Thu, 28 Sep 2023 08:42:45 GMT", "version": "v2" } ]
2023-09-29
[ [ "Baglio", "J.", "" ], [ "Campanario", "F.", "" ], [ "Glaus", "S.", "" ], [ "Mühlleitner", "M.", "" ], [ "Ronca", "J.", "" ], [ "Spira", "M.", "" ] ]
After the discovery of the Higgs boson in 2012 at the CERN Large Hadron Collider (LHC), the study of its properties still leaves room for an extended Higgs sector with more than one Higgs boson. 2-Higgs Doublet Models (2HDMs) are well-motivated extensions of the Standard Model (SM) with five physical Higgs bosons: two CP-even states $h$ and $H$, one CP-odd state $A$, and two charged states $H^\pm_{}$. In this letter, we present the calculation of the full next-to-leading order (NLO) QCD corrections to $hH$ and $AA$ production at the LHC in the 2HDM at small values of the ratio of the vacuum expectation values, $\tan\beta$, including the exact top-mass dependence everywhere in the calculation. Using techniques applied in the NLO QCD SM Higgs pair production calculation, we present results for the total cross section as well as for the invariant Higgs-pair-mass distribution at the LHC. We also provide the top-quark scale and scheme uncertainties which are found to be sizeable.
hep-ph/0402051
Byung-Yoon Park
Byung-Yoon Park, Hee-Jung Lee, Vicente Vento, Joon-Il Kim, Dong-Pil Min and Mannque Rho
Topological Structure of Dense Hadronic Matter
13 pages, 8 figures, Talk given at the KIAS-APCTP Symposium in Astro-Hadron Physics "Compact Stars: Quest for New States of Dense Matter", November 10-14, 2003, Seoul, Korea, published by World Scientific. Based on talk by B.-Y. Park
null
10.1142/9789812702524_0022
null
hep-ph nucl-th
null
We present a summary of work done on dense hadronic matter, based on the Skyrme model, which provides a unified approach to high density, valid in the large $N_c$ limit. In our picture, dense hadronic matter is described by the {\em classical} soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.
[ { "created": "Thu, 5 Feb 2004 04:17:25 GMT", "version": "v1" } ]
2017-08-23
[ [ "Park", "Byung-Yoon", "" ], [ "Lee", "Hee-Jung", "" ], [ "Vento", "Vicente", "" ], [ "Kim", "Joon-Il", "" ], [ "Min", "Dong-Pil", "" ], [ "Rho", "Mannque", "" ] ]
We present a summary of work done on dense hadronic matter, based on the Skyrme model, which provides a unified approach to high density, valid in the large $N_c$ limit. In our picture, dense hadronic matter is described by the {\em classical} soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.
2109.03033
Andr\`ee Dafne Bolognino
Andr\`ee Dafne Bolognino
From semi-hard processes to the unintegrated gluon distribution: a phenomenological path in the high-energy framework
195 pages, 48 figures, PhD thesis
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The class of semi-hard reactions represents a promising venue where to enhance our knowledge of strong interactions and deepen the aspects related to this theory in kinematical regimes so far unexplored. In particular, the high energies reached in electron-proton and in proton-proton collisions first at HERA and then at the LHC, allow us to study scattering amplitudes of hard and semi-hard processes in perturbative QCD. The structure of this thesis can be considered twofold. On one hand, the possibility to distinguish those channels where at least two final-state particles are emitted with large separation in rapidity and with an untagged system, permits to test the BFKL dynamics as resummation energy logarithms in the $t$-channel. In the BFKL formalism, the Mueller--Navelet jets process has been one of the most investigated reactions. With the idea of deepening our understanding of the BFKL approach, a new channel is proposed: the inclusive production of a light charged hadron and a jet with high transverse momentum widely separated in rapidity. The importance of this process relies in the possibility to probe a complementary region to one analyzed for the Mueller--Navelet jets. Additionally, another reaction is proposed: the heavy-quark pairs hadroproduction. On the other hand, also the class of processes featured by the detection of a single forward object in lepton-proton collision offers the opportunity to develop intriguing phenomenological studies. In particular, the exclusive leptoproduction of light vector mesons, $\rho$ and $\phi$, is exhaustively investigated. In this context, the study of helicity-dependent observables allows us to discriminate among several unintegrated gluon distribution models, whose original definition naturally encodes the BFKL-equation evolution dynamics. This kind of parton density allows us to get access to the hadronic structure at small-$x$.
[ { "created": "Tue, 7 Sep 2021 12:21:05 GMT", "version": "v1" } ]
2021-09-08
[ [ "Bolognino", "Andrèe Dafne", "" ] ]
The class of semi-hard reactions represents a promising venue where to enhance our knowledge of strong interactions and deepen the aspects related to this theory in kinematical regimes so far unexplored. In particular, the high energies reached in electron-proton and in proton-proton collisions first at HERA and then at the LHC, allow us to study scattering amplitudes of hard and semi-hard processes in perturbative QCD. The structure of this thesis can be considered twofold. On one hand, the possibility to distinguish those channels where at least two final-state particles are emitted with large separation in rapidity and with an untagged system, permits to test the BFKL dynamics as resummation energy logarithms in the $t$-channel. In the BFKL formalism, the Mueller--Navelet jets process has been one of the most investigated reactions. With the idea of deepening our understanding of the BFKL approach, a new channel is proposed: the inclusive production of a light charged hadron and a jet with high transverse momentum widely separated in rapidity. The importance of this process relies in the possibility to probe a complementary region to one analyzed for the Mueller--Navelet jets. Additionally, another reaction is proposed: the heavy-quark pairs hadroproduction. On the other hand, also the class of processes featured by the detection of a single forward object in lepton-proton collision offers the opportunity to develop intriguing phenomenological studies. In particular, the exclusive leptoproduction of light vector mesons, $\rho$ and $\phi$, is exhaustively investigated. In this context, the study of helicity-dependent observables allows us to discriminate among several unintegrated gluon distribution models, whose original definition naturally encodes the BFKL-equation evolution dynamics. This kind of parton density allows us to get access to the hadronic structure at small-$x$.
hep-ph/9401298
null
I. Bigi, B. Blok, M. Shifman, N. Uraltsev, A. Vainshtein
Non-Leptonic Decays of Beauty Hadrons -- from Phenomenology to Theory
26 pages + 2 PS figures attached. To appear in the second edition of the book `B Decays', S.Stone (ed.), World Scientific (Replaces the wrong LaTeX input with apologies for inconvenience)
null
null
CERN-TH.7132/94; TPI-MINN-94/1-T, UMN-TH-1234/94, UND-HEP-94-BIG01, TECHNION-PH-94-1
hep-ph
null
`Anyone who keeps the ability to see beauty never grows old' Franz Kafka. In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values. We discuss the implications of this discrepancy. The phenomenological engineering that has been developed for the description of {\em exclusive} two-body modes of $B$ mesons has reached a mature stage and awaits more precise and detailed experimental tests. First steps towards a genuine QCD treatment of these modes are being made.
[ { "created": "Thu, 20 Jan 1994 21:35:19 GMT", "version": "v1" }, { "created": "Fri, 21 Jan 1994 23:43:56 GMT", "version": "v2" } ]
2009-09-25
[ [ "Bigi", "I.", "" ], [ "Blok", "B.", "" ], [ "Shifman", "M.", "" ], [ "Uraltsev", "N.", "" ], [ "Vainshtein", "A.", "" ] ]
`Anyone who keeps the ability to see beauty never grows old' Franz Kafka. In the last few years considerable progress has been achieved in our understanding of the decays of heavy flavour hadrons. One can now calculate inclusive transition rates in QCD proper through an expansion in inverse powers of the heavy flavour quark mass without recourse to phenomenological assumptions. The non-perturbative contributions are treated systematically in this way; they are found to produce corrections of order a few percent in beauty decays, i.e. typically somewhat smaller than the perturbative corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is predicted to be longer than that of $B^0$ mesons by several percent. (b) The QCD prediction for the semileptonic branching ratio of $B$ mesons appears to exceed present experimental values. We discuss the implications of this discrepancy. The phenomenological engineering that has been developed for the description of {\em exclusive} two-body modes of $B$ mesons has reached a mature stage and awaits more precise and detailed experimental tests. First steps towards a genuine QCD treatment of these modes are being made.
hep-ph/9309210
Juan Carlos Montero
J. C. Montero and V. Pleitez
Constraints on spin-3/2 and excited spin-1/2 fermions coming from the leptonic Z0-partial width
Typeset using REVTEX 2.0, 9 pages and 3 figures (available upon request)
Phys.Lett. B321 (1994) 267-270
10.1016/0370-2693(94)90475-8
IFT-P.055/93
hep-ph
null
We consider effective interactions among excited spin-1/2 and spin-3/2 leptons with the usual ones. Assuming that these new leptons are lighter than the Z0 we will study the constraints on their masses and compositeness scale coming from the leptonic Z0 partial width.
[ { "created": "Wed, 1 Sep 1993 16:00:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Montero", "J. C.", "" ], [ "Pleitez", "V.", "" ] ]
We consider effective interactions among excited spin-1/2 and spin-3/2 leptons with the usual ones. Assuming that these new leptons are lighter than the Z0 we will study the constraints on their masses and compositeness scale coming from the leptonic Z0 partial width.
hep-ph/9610488
Meng Ta-Chung
C. Boros, Liang Zuo-tang and Meng Ta-chung
Spin-effects and dissociation of space-like photons
null
null
null
null
hep-ph
null
Talk presented by Meng Ta-chung at the 12th International Symposium on High Energy Spin Physics, SPIN96, Amsterdam, September 10-14,1996.
[ { "created": "Fri, 25 Oct 1996 12:35:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Boros", "C.", "" ], [ "Zuo-tang", "Liang", "" ], [ "Ta-chung", "Meng", "" ] ]
Talk presented by Meng Ta-chung at the 12th International Symposium on High Energy Spin Physics, SPIN96, Amsterdam, September 10-14,1996.
2212.02534
Samadrita Mukherjee
Triparno Bandyopadhyay, Ankita Budhraja, Samadrita Mukherjee, Tuhin S. Roy
A twisted tale of the transverse-mass tail
24 pages, 7 figures, a new appendix added, version published in JHEP
JHEP08(2023)135
10.1007/JHEP08(2023)135
TIFR/TH/23-4
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We propose a tantalizing possibility that misinterpretation of the reconstructed missing momentum may have yielded the observed discrepancies among measurements of the $W$-mass in different collider experiments. We introduce a proof-of-principle scenario characterized by a new physics particle, which can be produced associated with the $W$-boson in hadron collisions and contributes to the net missing momentum observed in a detector. We show that these exotic events pass the selection criteria imposed by various collaborations at reasonably high rates. Consequently, in the presence of even a handful of these events, a fit based on the ansatz that the missing momentum is primarily due to neutrinos (as it happens in the Standard Model), yields a $W$-boson mass that differs from its true value. Moreover, the best fit mass depends on the nature of the collider and the center-of-mass energy of collisions. We construct a barebones model that demonstrates this possibility quantitatively while satisfying current constraints. Interestingly, we find that the nature of the new physics particle and its interactions appear as a variation of the physics of Axion-like particles after a field redefinition.
[ { "created": "Mon, 5 Dec 2022 19:00:37 GMT", "version": "v1" }, { "created": "Tue, 22 Aug 2023 09:03:50 GMT", "version": "v2" } ]
2023-08-23
[ [ "Bandyopadhyay", "Triparno", "" ], [ "Budhraja", "Ankita", "" ], [ "Mukherjee", "Samadrita", "" ], [ "Roy", "Tuhin S.", "" ] ]
We propose a tantalizing possibility that misinterpretation of the reconstructed missing momentum may have yielded the observed discrepancies among measurements of the $W$-mass in different collider experiments. We introduce a proof-of-principle scenario characterized by a new physics particle, which can be produced associated with the $W$-boson in hadron collisions and contributes to the net missing momentum observed in a detector. We show that these exotic events pass the selection criteria imposed by various collaborations at reasonably high rates. Consequently, in the presence of even a handful of these events, a fit based on the ansatz that the missing momentum is primarily due to neutrinos (as it happens in the Standard Model), yields a $W$-boson mass that differs from its true value. Moreover, the best fit mass depends on the nature of the collider and the center-of-mass energy of collisions. We construct a barebones model that demonstrates this possibility quantitatively while satisfying current constraints. Interestingly, we find that the nature of the new physics particle and its interactions appear as a variation of the physics of Axion-like particles after a field redefinition.
hep-ph/9504363
Hyun-Chul Kim
Hyun-Chul Kim, Andree Blotz, Maxim V. Polyakov and Klaus Goeke
Electromagnetic Form Factors of the SU(3) Octet Baryons in the semibosonized SU(3) Nambu-Jona-Lasinio Model
RevTex is used. 37 pages. The final version to appear in Phys. Rev. D. 13 figures are included
Phys.Rev.D53:4013-4029,1996
10.1103/PhysRevD.53.4013
RUB-TPII-7/95
hep-ph
null
The electromagnetic form factors of the SU(3) octet baryons are investigated in the semibosonized SU(3) Nambu--Jona-Lasinio model (chiral quark-soliton model). The rotational $1/N_c$ and strange quark mass corrections in linear order are taken into account. The electromagnetic charge radii of the nucleon and magnetic moments are also evaluated. It turns out that the model is in a remarkable good agreement with the experimental data.
[ { "created": "Sat, 22 Apr 1995 10:48:34 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 1995 17:32:36 GMT", "version": "v2" }, { "created": "Fri, 1 Dec 1995 09:15:14 GMT", "version": "v3" } ]
2014-11-17
[ [ "Kim", "Hyun-Chul", "" ], [ "Blotz", "Andree", "" ], [ "Polyakov", "Maxim V.", "" ], [ "Goeke", "Klaus", "" ] ]
The electromagnetic form factors of the SU(3) octet baryons are investigated in the semibosonized SU(3) Nambu--Jona-Lasinio model (chiral quark-soliton model). The rotational $1/N_c$ and strange quark mass corrections in linear order are taken into account. The electromagnetic charge radii of the nucleon and magnetic moments are also evaluated. It turns out that the model is in a remarkable good agreement with the experimental data.
hep-ph/0108112
Graham Ross
S. F. King and G. G. Ross
Fermion Masses and Mixing Angles from SU(3) Family Symmetry
Minor changes. Version to appear in Phys.Lett B. 16 pages, latex
Phys.Lett. B520 (2001) 243-253
10.1016/S0370-2693(01)01139-X
null
hep-ph
null
We propose a model based on SU(3) family symmetry which leads to a successful description of quark and lepton masses and mixing angles including approximate bi-maximal mixing in the neutrino sector suitable for the LOW or quasi-vacuum solar solutions, with the atmospheric angle predicted to be accurately maximal due to the SU(3) symmetry. The model predicts a CHOOZ angle $\theta_{13}\sim |V_{ub}|.$ The SU(3) symmetry can also ensure the near degeneracy of squarks and sleptons needed to avoid large flavour changing neutral currents.
[ { "created": "Mon, 13 Aug 2001 17:42:08 GMT", "version": "v1" }, { "created": "Wed, 15 Aug 2001 17:41:15 GMT", "version": "v2" }, { "created": "Tue, 25 Sep 2001 11:36:15 GMT", "version": "v3" } ]
2009-11-07
[ [ "King", "S. F.", "" ], [ "Ross", "G. G.", "" ] ]
We propose a model based on SU(3) family symmetry which leads to a successful description of quark and lepton masses and mixing angles including approximate bi-maximal mixing in the neutrino sector suitable for the LOW or quasi-vacuum solar solutions, with the atmospheric angle predicted to be accurately maximal due to the SU(3) symmetry. The model predicts a CHOOZ angle $\theta_{13}\sim |V_{ub}|.$ The SU(3) symmetry can also ensure the near degeneracy of squarks and sleptons needed to avoid large flavour changing neutral currents.
hep-ph/9504241
Mariano Quiros
J.R. Espinosa (DESY) and M. Quiros (CERN)
IMPROVED METASTABILITY BOUNDS ON THE STANDARD MODEL HIGGS MASS
23 pages, Latex + pssfig.sty, 9 uuencoded tar-compressed figures in file fig.uu
Phys.Lett.B353:257-266,1995
10.1016/0370-2693(95)00572-3
CERN-TH/95-18, DESY 95-039
hep-ph
null
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the Standard Model at finite (and zero) temperature can have a deep and unphysical stable minimum $\langle \phi(T)\rangle$ at values of the field much larger than $G_F^{-1/2}$. We have computed absolute lower bounds on $M_H$, as a function of $M_t$, imposing the condition of no decay by thermal fluctuations, or quantum tunnelling, to the stable minimum. Our effective potential at zero temperature includes all next-to-leading logarithmic corrections (making it extremely scale-independent), and we have used pole masses for the Higgs-boson and top-quark. Thermal corrections to the effective potential include plasma effects by one-loop ring resummation of Debye masses. All calculations, including the effective potential and the bubble nucleation rate, are performed numerically, and so the results do not rely on any kind of analytical approximation. Easy-to-use fits are provided for the benefit of the reader. Conclusions on the possible Higgs detection at LEP-200 are drawn.
[ { "created": "Thu, 6 Apr 1995 09:58:03 GMT", "version": "v1" } ]
2010-04-06
[ [ "Espinosa", "J. R.", "", "DESY" ], [ "Quiros", "M.", "", "CERN" ] ]
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the Standard Model at finite (and zero) temperature can have a deep and unphysical stable minimum $\langle \phi(T)\rangle$ at values of the field much larger than $G_F^{-1/2}$. We have computed absolute lower bounds on $M_H$, as a function of $M_t$, imposing the condition of no decay by thermal fluctuations, or quantum tunnelling, to the stable minimum. Our effective potential at zero temperature includes all next-to-leading logarithmic corrections (making it extremely scale-independent), and we have used pole masses for the Higgs-boson and top-quark. Thermal corrections to the effective potential include plasma effects by one-loop ring resummation of Debye masses. All calculations, including the effective potential and the bubble nucleation rate, are performed numerically, and so the results do not rely on any kind of analytical approximation. Easy-to-use fits are provided for the benefit of the reader. Conclusions on the possible Higgs detection at LEP-200 are drawn.
2310.20631
Cameron Parker
Cameron Parker, Aaron Angerami, Ritu Arora, Steffen Bass, Shanshan Cao, Yi Chen, Raymond Ehlers, Hannah Elfner, Wenkai Fan, Rainer J. Fries, Charles Gale, Yayun He, Ulrich Heinz, Barbara Jacak, Peter Jacobs, Sangyong Jeon, Yi Ji, Lauren Kasper, Michael Kordell II, Amit Kumar, Joseph Latessa, Yen-Jie Lee, Roy Lemmon, Dananjaya Liyanage, Arthur Lopez, Matt Luzum, Abhijit Majumder, Simon Mak, Andi Mankolli, Christal Martin, Haydar Mehryar, Tanner Mengel, James Mulligan, Christine Nattrass, Jaime Norman, Jean-Francois Paquet, Joern H. Putschke, Gunther Roland, Bjoern Schenke, Loren Schwiebert, Arjun Sengupta, Chun Shen, Chathuranga Sirimanna, Ron A. Soltz, Ismail Soudi, Michael Strickland, Yasuki Tachibana, Julia Velkovska, Gojko Vujanovic, Xin-Nian Wang, Wenbin Zhao (The JETSCAPE Collaboration)
Hybrid Hadronization of Jet Showers from $e^++e^-$ to $A+A$ with JETSCAPE
6 pages, 4 figures, Hard Probes 2023 conference, accepted for publication in Proceedings of Science: version 2, references added, typos fixed
null
null
null
hep-ph nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
In this talk we review jet production in a large variety of collision systems using the JETSCAPE event generator and Hybrid Hadronization. Hybrid Hadronization combines quark recombination, applicable when distances between partons in phase space are small, and string fragmentation appropriate for dilute parton systems. It can therefore smoothly describe the transition from very dilute parton systems like $e^++e^-$ to full $A+A$ collisions. We test this picture by using JETSCAPE to generate jets in various systems. Comparison to experimental data in $e^++e^-$ and $p+p$ collisions allows for a precise tuning of vacuum baseline parameters in JETSCAPE and Hybrid Hadronization. Proceeding to systems with jets embedded in a medium, we study in-medium hadronization for jet showers. We quantify the effects of an ambient medium, focusing in particular on the dependence on the collective flow and size of the medium. Our results clarify the effects we expect from in-medium hadronization of jets on observables like fragmentation functions, hadron chemistry and jet shape.
[ { "created": "Tue, 31 Oct 2023 17:00:01 GMT", "version": "v1" }, { "created": "Fri, 3 Nov 2023 16:06:19 GMT", "version": "v2" }, { "created": "Tue, 7 Nov 2023 21:15:03 GMT", "version": "v3" } ]
2023-11-09
[ [ "Parker", "Cameron", "", "The JETSCAPE Collaboration" ], [ "Angerami", "Aaron", "", "The JETSCAPE Collaboration" ], [ "Arora", "Ritu", "", "The JETSCAPE Collaboration" ], [ "Bass", "Steffen", "", "The JETSCAPE Collaboration" ], [ "Cao", "Shanshan", "", "The JETSCAPE Collaboration" ], [ "Chen", "Yi", "", "The JETSCAPE Collaboration" ], [ "Ehlers", "Raymond", "", "The JETSCAPE Collaboration" ], [ "Elfner", "Hannah", "", "The JETSCAPE Collaboration" ], [ "Fan", "Wenkai", "", "The JETSCAPE Collaboration" ], [ "Fries", "Rainer J.", "", "The JETSCAPE Collaboration" ], [ "Gale", "Charles", "", "The JETSCAPE Collaboration" ], [ "He", "Yayun", "", "The JETSCAPE Collaboration" ], [ "Heinz", "Ulrich", "", "The JETSCAPE Collaboration" ], [ "Jacak", "Barbara", "", "The JETSCAPE Collaboration" ], [ "Jacobs", "Peter", "", "The JETSCAPE Collaboration" ], [ "Jeon", "Sangyong", "", "The JETSCAPE Collaboration" ], [ "Ji", "Yi", "", "The JETSCAPE Collaboration" ], [ "Kasper", "Lauren", "", "The JETSCAPE Collaboration" ], [ "Kordell", "Michael", "II", "The JETSCAPE Collaboration" ], [ "Kumar", "Amit", "", "The JETSCAPE Collaboration" ], [ "Latessa", "Joseph", "", "The JETSCAPE Collaboration" ], [ "Lee", "Yen-Jie", "", "The JETSCAPE Collaboration" ], [ "Lemmon", "Roy", "", "The JETSCAPE Collaboration" ], [ "Liyanage", "Dananjaya", "", "The JETSCAPE Collaboration" ], [ "Lopez", "Arthur", "", "The JETSCAPE Collaboration" ], [ "Luzum", "Matt", "", "The JETSCAPE Collaboration" ], [ "Majumder", "Abhijit", "", "The JETSCAPE Collaboration" ], [ "Mak", "Simon", "", "The JETSCAPE Collaboration" ], [ "Mankolli", "Andi", "", "The JETSCAPE Collaboration" ], [ "Martin", "Christal", "", "The JETSCAPE Collaboration" ], [ "Mehryar", "Haydar", "", "The JETSCAPE Collaboration" ], [ "Mengel", "Tanner", "", "The JETSCAPE Collaboration" ], [ "Mulligan", "James", "", "The JETSCAPE Collaboration" ], [ "Nattrass", "Christine", "", "The JETSCAPE Collaboration" ], [ "Norman", "Jaime", "", "The JETSCAPE Collaboration" ], [ "Paquet", "Jean-Francois", "", "The JETSCAPE Collaboration" ], [ "Putschke", "Joern H.", "", "The JETSCAPE Collaboration" ], [ "Roland", "Gunther", "", "The JETSCAPE Collaboration" ], [ "Schenke", "Bjoern", "", "The JETSCAPE Collaboration" ], [ "Schwiebert", "Loren", "", "The JETSCAPE Collaboration" ], [ "Sengupta", "Arjun", "", "The JETSCAPE Collaboration" ], [ "Shen", "Chun", "", "The JETSCAPE Collaboration" ], [ "Sirimanna", "Chathuranga", "", "The JETSCAPE Collaboration" ], [ "Soltz", "Ron A.", "", "The JETSCAPE Collaboration" ], [ "Soudi", "Ismail", "", "The JETSCAPE Collaboration" ], [ "Strickland", "Michael", "", "The JETSCAPE Collaboration" ], [ "Tachibana", "Yasuki", "", "The JETSCAPE Collaboration" ], [ "Velkovska", "Julia", "", "The JETSCAPE Collaboration" ], [ "Vujanovic", "Gojko", "", "The JETSCAPE Collaboration" ], [ "Wang", "Xin-Nian", "", "The JETSCAPE Collaboration" ], [ "Zhao", "Wenbin", "", "The JETSCAPE Collaboration" ] ]
In this talk we review jet production in a large variety of collision systems using the JETSCAPE event generator and Hybrid Hadronization. Hybrid Hadronization combines quark recombination, applicable when distances between partons in phase space are small, and string fragmentation appropriate for dilute parton systems. It can therefore smoothly describe the transition from very dilute parton systems like $e^++e^-$ to full $A+A$ collisions. We test this picture by using JETSCAPE to generate jets in various systems. Comparison to experimental data in $e^++e^-$ and $p+p$ collisions allows for a precise tuning of vacuum baseline parameters in JETSCAPE and Hybrid Hadronization. Proceeding to systems with jets embedded in a medium, we study in-medium hadronization for jet showers. We quantify the effects of an ambient medium, focusing in particular on the dependence on the collective flow and size of the medium. Our results clarify the effects we expect from in-medium hadronization of jets on observables like fragmentation functions, hadron chemistry and jet shape.
hep-ph/0504029
Claudio Destri
Claudio Destri and Andrea Sartirana
The renormalized and Renormalization-Group invariant Hartree-Fock approximation
32 pages, 13 figures
Phys.Rev. D72 (2005) 065003
10.1103/PhysRevD.72.065003
Bicocca-FT-05-7
hep-ph
null
We study the renormalization problem for the Hartree--Fock approximation of the $O(N)-$invariant $\phi^4$ model in the symmetric phase and show how to systematically improve the corresponding diagrammatic resummation to achieve the correct renormalization properties of the effective field equations, including Renormalization--Group invariance with the one--loop beta function. These new Hartree--Fock dynamics is still of mean field type but includes memory effects which are generically nonlocal also in space.
[ { "created": "Tue, 5 Apr 2005 15:51:39 GMT", "version": "v1" } ]
2009-11-11
[ [ "Destri", "Claudio", "" ], [ "Sartirana", "Andrea", "" ] ]
We study the renormalization problem for the Hartree--Fock approximation of the $O(N)-$invariant $\phi^4$ model in the symmetric phase and show how to systematically improve the corresponding diagrammatic resummation to achieve the correct renormalization properties of the effective field equations, including Renormalization--Group invariance with the one--loop beta function. These new Hartree--Fock dynamics is still of mean field type but includes memory effects which are generically nonlocal also in space.
hep-ph/9608379
Brian Harris
B. W. Harris (Florida State University)
Electroproduction of heavy quarks at NLO
To appear in proceedings of the 1996 Meeting of the American Physical Society, Division of Particles and Fields (DPF 96), Minneapolis, Minnesota, 10-15 Aug 1996. 3 pages, Latex using sprocl.sty (included)
null
null
null
hep-ph
null
A new next-to-leading order Monte Carlo program for the calculation of fully differential heavy quark cross sections in electroproduction is described. A comparison between the theoretical predictions and the latest charm production data from H1 and ZEUS at HERA is presented.
[ { "created": "Tue, 20 Aug 1996 17:57:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Harris", "B. W.", "", "Florida State University" ] ]
A new next-to-leading order Monte Carlo program for the calculation of fully differential heavy quark cross sections in electroproduction is described. A comparison between the theoretical predictions and the latest charm production data from H1 and ZEUS at HERA is presented.
1412.8352
Gui-Jun Ding
Peng Chen, Cai-Chang Li and Gui-Jun Ding
Lepton Flavor Mixing and CP Symmetry
24 pages, 3 figures
Phys. Rev. D 91, 033003 (2015)
10.1103/PhysRevD.91.033003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strategy of constraining the lepton flavor mixing from remnant CP symmetry is investigated in a rather general way. The neutrino mass matrix generally admits four remnant CP transformations which can be derived from the measured lepton mixing matrix in the charged lepton diagonal basis. Conversely, the lepton mixing matrix can be reconstructed from the postulated remnant CP transformations. All mixing angles and CP violating phases can be completely determined by the full set of remnant CP transformations or three of them. When one or two remnant CP transformations are preserved, the resulting lepton mixing matrix would depend on three real parameters or one real parameter respectively in addition to the parameters characterizing the remnant CP, and the concrete form of the mixing matrix is presented. The phenomenological predictions for the mixing parameters are discussed. The conditions leading to vanishing or maximal Dirac CP violation are studied.
[ { "created": "Mon, 29 Dec 2014 14:30:04 GMT", "version": "v1" } ]
2015-03-05
[ [ "Chen", "Peng", "" ], [ "Li", "Cai-Chang", "" ], [ "Ding", "Gui-Jun", "" ] ]
The strategy of constraining the lepton flavor mixing from remnant CP symmetry is investigated in a rather general way. The neutrino mass matrix generally admits four remnant CP transformations which can be derived from the measured lepton mixing matrix in the charged lepton diagonal basis. Conversely, the lepton mixing matrix can be reconstructed from the postulated remnant CP transformations. All mixing angles and CP violating phases can be completely determined by the full set of remnant CP transformations or three of them. When one or two remnant CP transformations are preserved, the resulting lepton mixing matrix would depend on three real parameters or one real parameter respectively in addition to the parameters characterizing the remnant CP, and the concrete form of the mixing matrix is presented. The phenomenological predictions for the mixing parameters are discussed. The conditions leading to vanishing or maximal Dirac CP violation are studied.
2012.02508
Natsumi Nagata
Tomohiro Abe, Koichi Hamaguchi, and Natsumi Nagata
Atomic Form Factors and Inverse Primakoff Scattering of Axion
15 pages, 3 figures; published version
null
10.1016/j.physletb.2021.136174
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/4.0/
We reexamine the inverse Primakoff scattering of axions, whose scattering cross section depends on the distribution of electrons in target atoms. We evaluate it using a form factor computed with a relativistic Hartree-Fock wave function and compare it with the previous results obtained with those based on the screened Coulomb potential for the electrostatic field in the atom. We take xenon as an example for the target atom and show that the scattering cross section was overestimated by more than an order of magnitude for axions with $\lesssim O(10)$ keV energies, like solar axions. It is also found that inelastic scattering processes, in which the final state contains an excited or ionized atom, can be comparable or even be dominant when the size of momentum transfer is $\lesssim 1$ keV. For more energetic axions, on the other hand, the total scattering cross section is found to be well approximated by a simple expression and has little dependence on the atomic structure. As an application of this result, we consider supernova axions, whose energy is 10-100 MeV, and show that $O(1)$ inverse Primakoff events are expected for axions from a nearby supernova in the future neutrino experiments, which may warrant a more detailed study on the search strategy of this process.
[ { "created": "Fri, 4 Dec 2020 10:26:12 GMT", "version": "v1" }, { "created": "Thu, 25 Feb 2021 14:05:20 GMT", "version": "v2" } ]
2021-03-03
[ [ "Abe", "Tomohiro", "" ], [ "Hamaguchi", "Koichi", "" ], [ "Nagata", "Natsumi", "" ] ]
We reexamine the inverse Primakoff scattering of axions, whose scattering cross section depends on the distribution of electrons in target atoms. We evaluate it using a form factor computed with a relativistic Hartree-Fock wave function and compare it with the previous results obtained with those based on the screened Coulomb potential for the electrostatic field in the atom. We take xenon as an example for the target atom and show that the scattering cross section was overestimated by more than an order of magnitude for axions with $\lesssim O(10)$ keV energies, like solar axions. It is also found that inelastic scattering processes, in which the final state contains an excited or ionized atom, can be comparable or even be dominant when the size of momentum transfer is $\lesssim 1$ keV. For more energetic axions, on the other hand, the total scattering cross section is found to be well approximated by a simple expression and has little dependence on the atomic structure. As an application of this result, we consider supernova axions, whose energy is 10-100 MeV, and show that $O(1)$ inverse Primakoff events are expected for axions from a nearby supernova in the future neutrino experiments, which may warrant a more detailed study on the search strategy of this process.