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1206.3934
Banafsheh Forghan
Banafsheh Forghan
Krein Regularization of \lambda\phi^4
null
International Journal of Theoretical Physics: Volume 51, Issue 5 (2012), Page 1503-1508
10.1007/s10773-011-1026-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the four-point function in \lambda\phi^4 theory by using Krein regularization and compare our result, which is finite, with the usual result in \lambda\phi^4 theory. The effective coupling constant (\lambda_\mu) is also calculated in this method.
[ { "created": "Fri, 27 Apr 2012 14:01:22 GMT", "version": "v1" } ]
2012-06-19
[ [ "Forghan", "Banafsheh", "" ] ]
We calculate the four-point function in \lambda\phi^4 theory by using Krein regularization and compare our result, which is finite, with the usual result in \lambda\phi^4 theory. The effective coupling constant (\lambda_\mu) is also calculated in this method.
1504.00683
Nobuchika Okada
Nobuchika Okada and Satomi Okada
Simple brane-world inflationary models: an update
17 pages, 7 figures, an update of arXiv:1407.3544 with Planck 2015 results, typos corrected, new references added. arXiv admin note: substantial text overlap with arXiv:1412.8466
null
10.1142/S0217751X16500780
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology. Brane-world cosmological effect alters the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology. In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension. In order to maintain the consistency with the Planck 2015 results for the inflationary predictions in the standard cosmology, we find a lower bound on the five-dimensional Planck mass ($M_5$). On the other hand, the inflationary predictions laying outside of the Planck allowed region can be pushed into the allowed region by the brane-world cosmological effect with a suitable choice of $M_5$.
[ { "created": "Tue, 31 Mar 2015 19:56:27 GMT", "version": "v1" }, { "created": "Mon, 6 Apr 2015 21:46:41 GMT", "version": "v2" } ]
2016-06-01
[ [ "Okada", "Nobuchika", "" ], [ "Okada", "Satomi", "" ] ]
In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology. Brane-world cosmological effect alters the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology. In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension. In order to maintain the consistency with the Planck 2015 results for the inflationary predictions in the standard cosmology, we find a lower bound on the five-dimensional Planck mass ($M_5$). On the other hand, the inflationary predictions laying outside of the Planck allowed region can be pushed into the allowed region by the brane-world cosmological effect with a suitable choice of $M_5$.
1604.00179
Falk Wunderlich
Falk Wunderlich, Roman Yaresko, Burkhard Kampfer
Arguing on entropic and enthalpic first-order phase transitions in strongly interacting matter
13 pages, 5 figures
null
10.4236/jmp.2016.78077
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The pattern of isentropes in the vicinity of a first-order phase transition is proposed as a key for a sub-classification. While the confinement--deconfinement transition, conjectured to set in beyond a critical end point in the QCD phase diagram, is often related to an entropic transition and the apparently settled gas-liquid transition in nuclear matter is an enthalphic transition, the conceivable local isentropes w.r.t.\ "incoming" or "outgoing" serve as another useful guide for discussing possible implications, both in the presumed hydrodynamical expansion stage of heavy-ion collisions and the core-collapse of supernova explosions. Examples, such as the quark-meson model and two-phase models, are shown to distinguish concisely the different transitions.
[ { "created": "Fri, 1 Apr 2016 09:47:51 GMT", "version": "v1" } ]
2016-05-25
[ [ "Wunderlich", "Falk", "" ], [ "Yaresko", "Roman", "" ], [ "Kampfer", "Burkhard", "" ] ]
The pattern of isentropes in the vicinity of a first-order phase transition is proposed as a key for a sub-classification. While the confinement--deconfinement transition, conjectured to set in beyond a critical end point in the QCD phase diagram, is often related to an entropic transition and the apparently settled gas-liquid transition in nuclear matter is an enthalphic transition, the conceivable local isentropes w.r.t.\ "incoming" or "outgoing" serve as another useful guide for discussing possible implications, both in the presumed hydrodynamical expansion stage of heavy-ion collisions and the core-collapse of supernova explosions. Examples, such as the quark-meson model and two-phase models, are shown to distinguish concisely the different transitions.
2011.12181
Le Tho Hue
T. Phong Nguyen, T.T. Thuc, D.T. Si, T.T.Hong, L. T. Hue
Low energy phenomena of the lepton sector in an $A_4$ symmetry model with heavy inverse seesaw neutrinos
Matching the published version in PTEP
PTEP 2022 (2022) 023B01
10.1093/ptep/ptac002
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
An extension of the two Higgs doublet model including inverse seesaw neutrinos and neutral Higgs bosons was constructed based on the $A_4$ symmetry in order to explain the recent neutrino oscillation data. This model can distinguish two well-known normal and inverted order schemes of neutrino data once both the effective masses $m_{\beta}$ in tritium beta decays and $\langle m\rangle$ in the neutrinoless double beta decay are observed. The lepton flavor violating decays of the charged leptons $e_b\rightarrow e_a\gamma$, $\mu\rightarrow3e$, the Standard model-like Higgs boson decays $h\rightarrow e_be_a$, and the $\mu$-e conversions in some nuclei are generated from loop corrections. The experimental data of the branching ratio Br$(\mu\rightarrow e\gamma, 3e)$ predict that the upper bounds of Br$(\tau \rightarrow \mu\gamma,e\gamma)$ and Br$(h\rightarrow e_{a}e_b)$ are much smaller than the planned experimental sensitivities. In contrast, the $\mu$-e conversions are the promising signals for experiments.
[ { "created": "Tue, 24 Nov 2020 15:57:43 GMT", "version": "v1" }, { "created": "Thu, 10 Feb 2022 08:24:55 GMT", "version": "v2" } ]
2022-02-18
[ [ "Nguyen", "T. Phong", "" ], [ "Thuc", "T. T.", "" ], [ "Si", "D. T.", "" ], [ "Hong", "T. T.", "" ], [ "Hue", "L. T.", "" ] ]
An extension of the two Higgs doublet model including inverse seesaw neutrinos and neutral Higgs bosons was constructed based on the $A_4$ symmetry in order to explain the recent neutrino oscillation data. This model can distinguish two well-known normal and inverted order schemes of neutrino data once both the effective masses $m_{\beta}$ in tritium beta decays and $\langle m\rangle$ in the neutrinoless double beta decay are observed. The lepton flavor violating decays of the charged leptons $e_b\rightarrow e_a\gamma$, $\mu\rightarrow3e$, the Standard model-like Higgs boson decays $h\rightarrow e_be_a$, and the $\mu$-e conversions in some nuclei are generated from loop corrections. The experimental data of the branching ratio Br$(\mu\rightarrow e\gamma, 3e)$ predict that the upper bounds of Br$(\tau \rightarrow \mu\gamma,e\gamma)$ and Br$(h\rightarrow e_{a}e_b)$ are much smaller than the planned experimental sensitivities. In contrast, the $\mu$-e conversions are the promising signals for experiments.
hep-ph/0403273
Enqvist Kari
Kari Enqvist
Curvatons in the minimally supersymmetric standard model
16 pages, 1 Figure
Mod.Phys.Lett. A19 (2004) 1421-1434
10.1142/S0217732304013970
HIP-2004-10/TH
hep-ph
null
Curvaton is an effectively massless field whose energy density during inflation is negligible but which later becomes dominant. This is a novel mechanism to generate the scale invariant perturbations. I discuss the possibility that the curvaton could be found among the fields of the minimally supersymmetric standard model (MSSM), which contains a number of flat directions along which the renormalizable potential vanishes. The requirements of late domination and the absence of damping of the perturbations pick out essentially a unique candidate for the MSSM curvaton. One must also require that inflation takes place in a hidden sector. If the inflaton energy density can be radiated into extra dimensions, many constraints can be relaxed, and the simplest flat direction consisting of the Higgses H_u and H_d would provide a working example of an MSSM curvaton.
[ { "created": "Fri, 26 Mar 2004 22:13:01 GMT", "version": "v1" }, { "created": "Fri, 2 Apr 2004 06:50:06 GMT", "version": "v2" } ]
2009-11-10
[ [ "Enqvist", "Kari", "" ] ]
Curvaton is an effectively massless field whose energy density during inflation is negligible but which later becomes dominant. This is a novel mechanism to generate the scale invariant perturbations. I discuss the possibility that the curvaton could be found among the fields of the minimally supersymmetric standard model (MSSM), which contains a number of flat directions along which the renormalizable potential vanishes. The requirements of late domination and the absence of damping of the perturbations pick out essentially a unique candidate for the MSSM curvaton. One must also require that inflation takes place in a hidden sector. If the inflaton energy density can be radiated into extra dimensions, many constraints can be relaxed, and the simplest flat direction consisting of the Higgses H_u and H_d would provide a working example of an MSSM curvaton.
0708.3364
Jonathan Bagger
Jonathan A. Bagger and Adam F. Falk
Decoupling and Destabilizing in Spontaneously Broken Supersymmetry
Letex, 7 pages
Phys.Rev.D76:105026,2007
10.1103/PhysRevD.76.105026
null
hep-ph hep-th
null
The supersymmetric analog of the Goldberger-Treiman relation plays a critical role in the low energy effective theory of models in which supersymmetry is spontaneously broken in a hidden sector. The interactions that connect the hidden and visible sectors break a global symmetry, which implies that the low energy theory must be constructed consistently in inverse powers of the messenger scale. The Goldberger-Treiman relation determines the couplings of the Goldstino to the visible sector fields. These couplings are fixed by the soft supersymmetry breaking terms within a power counting scheme that is stable under radiative corrections. We describe the power counting of the low energy effective theory, first for a toy model of extended technicolor and then for the supersymmetric standard model. One implication of this work for supersymmetry phenomenology is the observation that Goldstino loops can destabilize the weak scale if the low energy theory is not constructed consistently. Another is that Goldstino loops induce all visible sector operators not forbidden by symmetries. The magnitudes of these operators are determined by the consistent power counting of the low energy effective theory.
[ { "created": "Fri, 24 Aug 2007 16:02:05 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bagger", "Jonathan A.", "" ], [ "Falk", "Adam F.", "" ] ]
The supersymmetric analog of the Goldberger-Treiman relation plays a critical role in the low energy effective theory of models in which supersymmetry is spontaneously broken in a hidden sector. The interactions that connect the hidden and visible sectors break a global symmetry, which implies that the low energy theory must be constructed consistently in inverse powers of the messenger scale. The Goldberger-Treiman relation determines the couplings of the Goldstino to the visible sector fields. These couplings are fixed by the soft supersymmetry breaking terms within a power counting scheme that is stable under radiative corrections. We describe the power counting of the low energy effective theory, first for a toy model of extended technicolor and then for the supersymmetric standard model. One implication of this work for supersymmetry phenomenology is the observation that Goldstino loops can destabilize the weak scale if the low energy theory is not constructed consistently. Another is that Goldstino loops induce all visible sector operators not forbidden by symmetries. The magnitudes of these operators are determined by the consistent power counting of the low energy effective theory.
1905.11309
Nelson R. F. Braga
Nelson R. F. Braga and Luiz F. Ferreira
Quasinormal modes for quarkonium in a plasma with magnetic fields
20 pages, 2 tables, 10 figures
null
10.1016/j.physletb.2019.06.050
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy vector mesons detected after a heavy ion collision are important sources of information about the quark gluon plasma. The fraction of such particles that survive the plasma phase and reach the detectors is related to the dissociation degree inside the thermal medium. A consistent picture for the thermal behavior of charmonium and bottomonium quasi-states in a thermal medium was obtained recently using a holographic bottom up model. This model captures the heavy flavour spectroscopy of masses and decay constants in the vacuum (zero temperature) and is consistently extended to finite temperature. The spectral functions that emerge provide a description of the dissociation process in terms of the broadening of the quasi-state peaks with temperature. The holographic approach makes it possible to determine also the quasinormal modes. They are gravity solutions representing the quasi-particle states in the thermal medium, with complex frequencies related to the thermal mass and width. The quasinormal modes for charmonium and bottomonium have been studied very recently and a consistent description of the dissociation process was found. An additional factor can affect the dissociation process: strong magnetic fields are expected to be present when the plasma is formed by non-central heavy ion collisions. So, it is important to understand the effect of such fields on the heavy meson dissociation scenario. Here we extend the holographic determination of quasinormal modes for the case when magnetic fields are present. The real and imaginary parts of the mode frequencies are determined for different values of background $e B$ field. The associated dispersion relations for heavy quarks moving inside the plasma are also investigated for both $ c \bar c$ and $ b \bar b \, $.
[ { "created": "Mon, 27 May 2019 15:50:10 GMT", "version": "v1" } ]
2019-07-24
[ [ "Braga", "Nelson R. F.", "" ], [ "Ferreira", "Luiz F.", "" ] ]
Heavy vector mesons detected after a heavy ion collision are important sources of information about the quark gluon plasma. The fraction of such particles that survive the plasma phase and reach the detectors is related to the dissociation degree inside the thermal medium. A consistent picture for the thermal behavior of charmonium and bottomonium quasi-states in a thermal medium was obtained recently using a holographic bottom up model. This model captures the heavy flavour spectroscopy of masses and decay constants in the vacuum (zero temperature) and is consistently extended to finite temperature. The spectral functions that emerge provide a description of the dissociation process in terms of the broadening of the quasi-state peaks with temperature. The holographic approach makes it possible to determine also the quasinormal modes. They are gravity solutions representing the quasi-particle states in the thermal medium, with complex frequencies related to the thermal mass and width. The quasinormal modes for charmonium and bottomonium have been studied very recently and a consistent description of the dissociation process was found. An additional factor can affect the dissociation process: strong magnetic fields are expected to be present when the plasma is formed by non-central heavy ion collisions. So, it is important to understand the effect of such fields on the heavy meson dissociation scenario. Here we extend the holographic determination of quasinormal modes for the case when magnetic fields are present. The real and imaginary parts of the mode frequencies are determined for different values of background $e B$ field. The associated dispersion relations for heavy quarks moving inside the plasma are also investigated for both $ c \bar c$ and $ b \bar b \, $.
hep-ph/9710293
Guest Account
S.V.Goloskokov
Spin Effects In Diffractive Processes at HERA
3 pages, latex, 2 PS figures, talk at the lp DESY Working Group meeting during the 2nd Topical Workshop Deep Inelastic Scattering off Polarized Target: Theory Meets Experiment, DESY Zeuthen, September 1-5, 1997
null
null
null
hep-ph
null
It is shown that the $A_{ll}$ asymmetry in diffractive $Q \bar Q$ leptoproduction is not small at HERA energies and dependent on the structure of the pomeron couplings and on the masses of produced quarks. The connection of this asymmetry with the non-forward gluon distribution in the proton is discussed.
[ { "created": "Thu, 9 Oct 1997 09:38:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Goloskokov", "S. V.", "" ] ]
It is shown that the $A_{ll}$ asymmetry in diffractive $Q \bar Q$ leptoproduction is not small at HERA energies and dependent on the structure of the pomeron couplings and on the masses of produced quarks. The connection of this asymmetry with the non-forward gluon distribution in the proton is discussed.
hep-ph/0308319
Stefan W. Bosch
Stefan W. Bosch
Factorization and Sudakov Resummation in B -> gamma l nu
3 pages, 1 figure; contribution to proceedings of "International Europhysics Conference on High Energy Physics" EPS (July 17th-23rd 2003) in Aachen; to appear in European Physical Journal C direct
Eur.Phys.J.C33:s294-s296,2004
10.1140/epjcd/s2003-03-208-0
CLNS 03/1842
hep-ph
null
We apply Soft-Collinear Effective Theory to prove at leading power in Lambda_QCD/m_b a factorization formula for the radiative leptonic decay B -> gamma l nu. Large logarithms entering the hard-scattering kernel are systematically resummed by a two-step perturbative matching procedure.
[ { "created": "Fri, 29 Aug 2003 17:35:22 GMT", "version": "v1" } ]
2011-09-13
[ [ "Bosch", "Stefan W.", "" ] ]
We apply Soft-Collinear Effective Theory to prove at leading power in Lambda_QCD/m_b a factorization formula for the radiative leptonic decay B -> gamma l nu. Large logarithms entering the hard-scattering kernel are systematically resummed by a two-step perturbative matching procedure.
0801.1566
Aleksi Kurkela
Ph. de Forcrand, A.Kurkela, A.Vuorinen
Center-Symmetric Effective Theory for High-Temperature SU(2) Yang-Mills Theory
24 pages, 6 figures. v2: small clarifications and updates; published version
Phys.Rev.D77:125014,2008
10.1103/PhysRevD.77.125014
CERN-PH-TH/2008-007
hep-ph hep-lat
null
We construct and study a dimensionally reduced effective theory for high-temperature SU(2) Yang-Mills theory that respects all the symmetries of the underlying theory. Our main motivation is to study, whether the correct treatment of the center symmetry can help extend the applicability of the dimensional reduction procedure towards the confinement transition. After performing perturbative matching to the full theory at asymptotically high temperatures, we map the phase diagram of the effective theory using non-perturbative lattice simulations. We find that at lower temperature the theory undergoes a second order confining phase transition, in complete analogy with the full theory, which is a direct consequence of having incorporated the center symmetry.
[ { "created": "Thu, 10 Jan 2008 20:57:00 GMT", "version": "v1" }, { "created": "Tue, 6 May 2008 09:43:51 GMT", "version": "v2" } ]
2008-11-26
[ [ "de Forcrand", "Ph.", "" ], [ "Kurkela", "A.", "" ], [ "Vuorinen", "A.", "" ] ]
We construct and study a dimensionally reduced effective theory for high-temperature SU(2) Yang-Mills theory that respects all the symmetries of the underlying theory. Our main motivation is to study, whether the correct treatment of the center symmetry can help extend the applicability of the dimensional reduction procedure towards the confinement transition. After performing perturbative matching to the full theory at asymptotically high temperatures, we map the phase diagram of the effective theory using non-perturbative lattice simulations. We find that at lower temperature the theory undergoes a second order confining phase transition, in complete analogy with the full theory, which is a direct consequence of having incorporated the center symmetry.
hep-ph/9504417
null
Anirban Kundu
Electroweak Precision Data and a Heavy Z'
LaTeX file, includes postscript of two figures. Title changed in published version. Replaces previous version.
Phys.Lett. B370 (1996) 135-140
10.1016/0370-2693(95)01559-0
SINP-TNP/95-07
hep-ph
null
We consider the physics of an extra $U(1)$ gauge boson $Z'$, which can mix with $Z$ through intermediate fermion loops. The loop contribution due to the heavy top quark significantly affects the low-energy observables, and for $m_{Z'}>m_Z$, one can always adjust the shifts in these observables to be in the right direction suggested by experiments, when we impose the anomaly cancellation conditions for $Z'$.
[ { "created": "Wed, 26 Apr 1995 07:46:00 GMT", "version": "v1" }, { "created": "Wed, 8 May 1996 13:22:46 GMT", "version": "v2" } ]
2009-10-28
[ [ "Kundu", "Anirban", "" ] ]
We consider the physics of an extra $U(1)$ gauge boson $Z'$, which can mix with $Z$ through intermediate fermion loops. The loop contribution due to the heavy top quark significantly affects the low-energy observables, and for $m_{Z'}>m_Z$, one can always adjust the shifts in these observables to be in the right direction suggested by experiments, when we impose the anomaly cancellation conditions for $Z'$.
2404.15112
Paolo Torrielli
Luca Buonocore, Luca Rottoli, and Paolo Torrielli
Resummation of combined QCD-electroweak effects in Drell Yan lepton-pair production
23 pages, 13 figures
null
null
ZU-TH 21/24, CERN-TH-2024-045
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider neutral- and charged-current Drell Yan lepton-pair production at hadron colliders, and include dominant classes of electroweak and mixed QCD-electroweak corrections to all orders in perturbation theory. The accurate description of these physical effects is vital for a precise determination of fundamental Standard Model parameters, such as the $W$-boson mass and the electroweak mixing angle, as well as for a solid assessment of the associated theoretical uncertainties. Our state-of-the-art resummation reaches next-to-leading-logarithmic accuracy in both the electroweak and the mixed QCD-electroweak perturbative expansions, including constant terms at first order beyond Born level in both couplings, i.e. at order $\alpha$ and $\alpha_s \alpha$. These effects are incorporated on top of QCD predictions at next-to-next-to-next-to-leading-logarithmic accuracy, which include constant terms at third order in the strong coupling. Our results retain, for the first time at this accuracy, full dependence on the kinematics of the final-state leptons, thereby enabling a realistic comparison with experimental analyses at the differential level in presence of fiducial cuts. We present a phenomenological analysis of the impact of electroweak corrections in relevant observables at the LHC. We find visible shape distortions in resummation-dominated kinematical regions with respect to pure-QCD predictions, highlighting the importance of a complete description, not limited to QCD, for precision Drell Yan physics.
[ { "created": "Tue, 23 Apr 2024 15:05:43 GMT", "version": "v1" } ]
2024-04-24
[ [ "Buonocore", "Luca", "" ], [ "Rottoli", "Luca", "" ], [ "Torrielli", "Paolo", "" ] ]
We consider neutral- and charged-current Drell Yan lepton-pair production at hadron colliders, and include dominant classes of electroweak and mixed QCD-electroweak corrections to all orders in perturbation theory. The accurate description of these physical effects is vital for a precise determination of fundamental Standard Model parameters, such as the $W$-boson mass and the electroweak mixing angle, as well as for a solid assessment of the associated theoretical uncertainties. Our state-of-the-art resummation reaches next-to-leading-logarithmic accuracy in both the electroweak and the mixed QCD-electroweak perturbative expansions, including constant terms at first order beyond Born level in both couplings, i.e. at order $\alpha$ and $\alpha_s \alpha$. These effects are incorporated on top of QCD predictions at next-to-next-to-next-to-leading-logarithmic accuracy, which include constant terms at third order in the strong coupling. Our results retain, for the first time at this accuracy, full dependence on the kinematics of the final-state leptons, thereby enabling a realistic comparison with experimental analyses at the differential level in presence of fiducial cuts. We present a phenomenological analysis of the impact of electroweak corrections in relevant observables at the LHC. We find visible shape distortions in resummation-dominated kinematical regions with respect to pure-QCD predictions, highlighting the importance of a complete description, not limited to QCD, for precision Drell Yan physics.
hep-ph/9604227
Sekretariat Phil. weg16
Christof Wetterich
Integrating out Gluons in Flow Equations
56 pages, Latex
Z.Phys. C72 (1996) 139-162
10.1007/s002880050232
HD-THEP-95-47
hep-ph
null
We present an exact nonperturbative flow equation for the average action for quarks which incorporates the effects of gluon fluctuations. With suitable truncations this allows one to compute effective multiquark interactions in dependence on an infrared scale $k$. Our method amounts to integrating out the gluons with momenta larger than $k$.
[ { "created": "Tue, 2 Apr 1996 10:14:57 GMT", "version": "v1" } ]
2009-10-28
[ [ "Wetterich", "Christof", "" ] ]
We present an exact nonperturbative flow equation for the average action for quarks which incorporates the effects of gluon fluctuations. With suitable truncations this allows one to compute effective multiquark interactions in dependence on an infrared scale $k$. Our method amounts to integrating out the gluons with momenta larger than $k$.
1702.07980
Bo Feng
Bo Feng, De-fu Hou, Hui Liu, Hai-cang Ren, Ping-ping Wu, and Yan Wu
Chiral Magnetic Effect in a Lattice Model
7 pages
Phys. Rev. D 95, 114023 (2017)
10.1103/PhysRevD.95.114023
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study analytically the one-loop contribution to the Chiral Magnetic Effect(CME) using lattice regularization with a Wilson fermion field. In the continuum limit, we find that the chiral magnetic current vanishes at nonzero temperature but emerges at zero temperature consistent with that found by Pauli-Villas regularization. For finite lattice size, however, the chiral magnetic current is nonvanishing at nonzero temperature. But the numerical vaule of the coefficient of CME current is very small compared with that extracted from the full QCD simulation for the same lattice parameters. The possibility of higher order corrections from QCD dynamics is also assessed.
[ { "created": "Sun, 26 Feb 2017 03:04:45 GMT", "version": "v1" } ]
2017-07-05
[ [ "Feng", "Bo", "" ], [ "Hou", "De-fu", "" ], [ "Liu", "Hui", "" ], [ "Ren", "Hai-cang", "" ], [ "Wu", "Ping-ping", "" ], [ "Wu", "Yan", "" ] ]
We study analytically the one-loop contribution to the Chiral Magnetic Effect(CME) using lattice regularization with a Wilson fermion field. In the continuum limit, we find that the chiral magnetic current vanishes at nonzero temperature but emerges at zero temperature consistent with that found by Pauli-Villas regularization. For finite lattice size, however, the chiral magnetic current is nonvanishing at nonzero temperature. But the numerical vaule of the coefficient of CME current is very small compared with that extracted from the full QCD simulation for the same lattice parameters. The possibility of higher order corrections from QCD dynamics is also assessed.
1101.3466
Cyrille Marquet
Cyrille Marquet
Azimuthal angle and rapidity dependence of di-hadron correlations in QCD
8 pages, 6 figures, Proceedings of the 4th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (HP2010), Eilat, Israel, October 10-15 2010
null
10.1016/j.nuclphysa.2011.02.033
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I discuss novel QCD phenomena recently observed in p+p, p+A and A+A collisions, that result from the non-linear dynamics of small-x gluons. I focus on di-hadron correlation measurements, as opposed to single-hadron observables often too inclusive to distinguish possible new effects from established mechanisms. Specifically, I discuss angular correlations of forward di-hadrons in d+Au collisions and long-range rapidity correlations in high-multiplicity p+p and Au+Au collisions.
[ { "created": "Tue, 18 Jan 2011 14:52:45 GMT", "version": "v1" } ]
2015-05-27
[ [ "Marquet", "Cyrille", "" ] ]
I discuss novel QCD phenomena recently observed in p+p, p+A and A+A collisions, that result from the non-linear dynamics of small-x gluons. I focus on di-hadron correlation measurements, as opposed to single-hadron observables often too inclusive to distinguish possible new effects from established mechanisms. Specifically, I discuss angular correlations of forward di-hadrons in d+Au collisions and long-range rapidity correlations in high-multiplicity p+p and Au+Au collisions.
hep-ph/0110344
Jan Fischer
Irinel Caprini and Jan Fischer
Analytic continuation and perturbative expansions in QCD
18 pages, latex, 5 figures in EPS format
Eur.Phys.J.C24:127-135,2002
10.1007/s100520100880
null
hep-ph
null
Starting from the divergence pattern of perturbative quantum chromodynamics, we propose a novel, non-power series replacing the standard expansion in powers of the renormalized coupling constant $a$. The coefficients of the new expansion are calculable at each finite order from the Feynman diagrams, while the expansion functions, denoted as $W_n(a)$, are defined by analytic continuation in the Borel complex plane. The infrared ambiguity of perturbation theory is manifest in the prescription dependence of the $W_n(a)$. We prove that the functions $W_n(a)$ have branch point and essential singularities at the origin $a=0$ of the complex $a$-plane and their perturbative expansions in powers of $a$ are divergent, while the expansion of the correlators in terms of the $W_n(a)$ set is convergent under quite loose conditions
[ { "created": "Fri, 26 Oct 2001 07:42:31 GMT", "version": "v1" } ]
2011-09-13
[ [ "Caprini", "Irinel", "" ], [ "Fischer", "Jan", "" ] ]
Starting from the divergence pattern of perturbative quantum chromodynamics, we propose a novel, non-power series replacing the standard expansion in powers of the renormalized coupling constant $a$. The coefficients of the new expansion are calculable at each finite order from the Feynman diagrams, while the expansion functions, denoted as $W_n(a)$, are defined by analytic continuation in the Borel complex plane. The infrared ambiguity of perturbation theory is manifest in the prescription dependence of the $W_n(a)$. We prove that the functions $W_n(a)$ have branch point and essential singularities at the origin $a=0$ of the complex $a$-plane and their perturbative expansions in powers of $a$ are divergent, while the expansion of the correlators in terms of the $W_n(a)$ set is convergent under quite loose conditions
0801.3071
Kazuhiro Tanaka
Hiroyuki Kawamura (1), Jiro Kodaira (2), Kazuhiro Tanaka (3) ((1) RIKEN, (2) KEK, (3) Juntendo Univ.)
The OPE of the B-meson light-cone wavefunction for exclusive B decays: radiative corrections and higher-dimensional operators
6 pages, to appear in the proceedings of 8th International Symposium on Radiative Corrections (RADCOR 2007), Florence, Italy, October 1-5; corrected typos
PoSRADCOR2007:049,2007
null
null
hep-ph
null
We discuss the B-meson light-cone wavefunction relevant for QCD factorization approach for exclusive B-meson decays. We derive the operator product expansion for the B-meson light-cone wavefunction, taking into account the local composite operators of dimension less than 6 and calculating the radiative corrections at order \alpha_s for the corresponding Wilson coefficients. The result embodies peculiar UV and IR behaviors of the B-meson light-cone wavefunction, the Sudakov-type double logarithmic effects and the mixing of the multiparticle states with additional gluons inside the B meson. The former effects are induced from the cusp singularity in the radiative corrections, while the latter is manifested by the participation of the higher-dimensional operators associated with the nonperturbative structure of the B meson.
[ { "created": "Sun, 20 Jan 2008 09:50:20 GMT", "version": "v1" }, { "created": "Mon, 28 Jan 2008 03:25:33 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kawamura", "Hiroyuki", "" ], [ "Kodaira", "Jiro", "" ], [ "Tanaka", "Kazuhiro", "" ] ]
We discuss the B-meson light-cone wavefunction relevant for QCD factorization approach for exclusive B-meson decays. We derive the operator product expansion for the B-meson light-cone wavefunction, taking into account the local composite operators of dimension less than 6 and calculating the radiative corrections at order \alpha_s for the corresponding Wilson coefficients. The result embodies peculiar UV and IR behaviors of the B-meson light-cone wavefunction, the Sudakov-type double logarithmic effects and the mixing of the multiparticle states with additional gluons inside the B meson. The former effects are induced from the cusp singularity in the radiative corrections, while the latter is manifested by the participation of the higher-dimensional operators associated with the nonperturbative structure of the B meson.
2407.08523
Kentaro Hayashi
Kentaro Hayashi, Yasuhiko Tsue
Modified dilepton production rate from charged pion-pair annihilation in the inhomogeneous chiral condensed phase
10 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the dilepton production rates from annihilation processes of charged pion pairs with modified pion dispersion relations in the inhomogeneous chiral condensed phase. We assume a dual chiral density wave as an inhomogeneous chiral condensate, and obtain the dispersion relations of the Nambu-Goldstone modes in the inhomogeneous chiral condensed phase. We use a low energy effective Lagrangian based on the O(4) symmetry which is expanded by the order parameter up to the sixth order. The obtained dispersion relations are anisotropic and quadratic for the momentum. We evaluate the electron-positron production rates by charged pion-pair annihilations as functions of an invariant mass using the obtained dispersion relations. Basically, the production rate in the inhomogeneous chiral condensed phase has a steeper overall slope with respect to an invariant mass than that in the homogeneous chiral condensed phase. Also, there may be a possibility that the production rate diverges when the invariant mass is just twice the pion mass.
[ { "created": "Thu, 11 Jul 2024 14:10:33 GMT", "version": "v1" } ]
2024-07-12
[ [ "Hayashi", "Kentaro", "" ], [ "Tsue", "Yasuhiko", "" ] ]
We investigate the dilepton production rates from annihilation processes of charged pion pairs with modified pion dispersion relations in the inhomogeneous chiral condensed phase. We assume a dual chiral density wave as an inhomogeneous chiral condensate, and obtain the dispersion relations of the Nambu-Goldstone modes in the inhomogeneous chiral condensed phase. We use a low energy effective Lagrangian based on the O(4) symmetry which is expanded by the order parameter up to the sixth order. The obtained dispersion relations are anisotropic and quadratic for the momentum. We evaluate the electron-positron production rates by charged pion-pair annihilations as functions of an invariant mass using the obtained dispersion relations. Basically, the production rate in the inhomogeneous chiral condensed phase has a steeper overall slope with respect to an invariant mass than that in the homogeneous chiral condensed phase. Also, there may be a possibility that the production rate diverges when the invariant mass is just twice the pion mass.
2110.09988
Pablo Mart\'inez-Mirav\'e
Pablo Mart\'inez-Mirav\'e
Cosmological radiation density with non-standard neutrino-electron interactions
5 pages, 2 figures. Based on arXiv:2105.08168. Proceedings for the 17th International Conference on Topics in Astroparticle and Underground Physics
null
10.1088/1742-6596/2156/1/012011
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Non-standard interactions (NSI) between neutrinos and electrons can significantly modify the decoupling of neutrinos from the plasma. These interactions have two effects on the overall picture: (i) they alter neutrino oscillations though matter effects and (ii) they modify the scattering and annihilation processes involving neutrinos and electrons and positrons. We study the role of non-universal and flavour-changing NSI in the decoupling and how they impact the determination of the effective number of neutrinos, $N_{eff}$. We examine the degeneracies between NSI parameters and we compare the expected sensitivity from future cosmological surveys with the current limits from terrestrial experiments. We outline the complementarity between both approaches.
[ { "created": "Tue, 19 Oct 2021 14:01:53 GMT", "version": "v1" } ]
2022-03-02
[ [ "Martínez-Miravé", "Pablo", "" ] ]
Non-standard interactions (NSI) between neutrinos and electrons can significantly modify the decoupling of neutrinos from the plasma. These interactions have two effects on the overall picture: (i) they alter neutrino oscillations though matter effects and (ii) they modify the scattering and annihilation processes involving neutrinos and electrons and positrons. We study the role of non-universal and flavour-changing NSI in the decoupling and how they impact the determination of the effective number of neutrinos, $N_{eff}$. We examine the degeneracies between NSI parameters and we compare the expected sensitivity from future cosmological surveys with the current limits from terrestrial experiments. We outline the complementarity between both approaches.
1610.04613
Torsten Bringmann
Torsten Bringmann, Ahmad Galea, Andrzej Hryczuk and Christoph Weniger
Novel Spectral Features in MeV Gamma Rays from Dark Matter
7 pages revtex4-1, 5 figures; minor updates in sensitivity figures and discussion. Matches published version
Phys. Rev. D 95, 043002 (2017)
10.1103/PhysRevD.95.043002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Astrophysical searches for gamma rays are one of the main strategies to probe the annihilation or decay of dark matter particles. We present a new class of distinct sub-GeV spectral features that generically appear in kinematical situations where the available center-of-mass energy in such processes is just above threshold to produce excited meson states. Using a Fisher forecast with realistic astrophysical backgrounds, we demonstrate that for upcoming experiments like e-ASTROGAM and ComPair these signals can turn out to be the smoking gun in the search for particle dark matter.
[ { "created": "Fri, 14 Oct 2016 20:00:00 GMT", "version": "v1" }, { "created": "Thu, 16 Feb 2017 21:42:44 GMT", "version": "v2" } ]
2017-02-20
[ [ "Bringmann", "Torsten", "" ], [ "Galea", "Ahmad", "" ], [ "Hryczuk", "Andrzej", "" ], [ "Weniger", "Christoph", "" ] ]
Astrophysical searches for gamma rays are one of the main strategies to probe the annihilation or decay of dark matter particles. We present a new class of distinct sub-GeV spectral features that generically appear in kinematical situations where the available center-of-mass energy in such processes is just above threshold to produce excited meson states. Using a Fisher forecast with realistic astrophysical backgrounds, we demonstrate that for upcoming experiments like e-ASTROGAM and ComPair these signals can turn out to be the smoking gun in the search for particle dark matter.
2311.18472
Francesco Romeo
Sehar Ajmal, Jethro Gaglione, Alfredo Gurrola, Orlando Panella, Matteo Presilla, Francesco Romeo, Hao Sun, She-Sheng Xue
Searching for exclusive leptoquarks with the Nambu-Jona-Lasinio composite model at the LHC and HL-LHC
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present a detailed study concerning a new physics scenario involving four fermion operators of the Nambu-Jona-Lasinio type characterized by a strong-coupling ultraviolet fixed point where composite particles are formed as bound states of elementary fermions at the scale $\Lambda ={\cal O}(\text{TeV})$. After implementing the model in the Universal FeynRules Output format, we focus on the phenomenology of the scalar leptoquarks at the LHC and the High-Luminosity option. Leptoquark particles have undergone extensive scrutiny in the literature and experimental searches, primarily relying on pair production and, more recently, incorporating single, t-channel, and lepton-induced processes. This study marks, for the first time, the examination of these production modes at varying jet multiplicities. Novel mechanisms emerge, enhancing the total production cross-section, especially for leptoquarks couplings to higher fermion generations. A global strategy is devised to capture all final state particles produced in association with leptoquarks or originating from their decay, which we termed ``exclusive'', in an analogy to the nomenclature used in nuclear reactions. The assessment of the significance in current and future LHC runs, focusing on the case of leptoquark coupling to a muon - $\textit{c}$ quark pair, reveals superior sensitivity compared to ongoing searches. Given this heightened discovery potential, we advocate the incorporation of exclusive leptoquark searches in future investigations at the LHC.
[ { "created": "Thu, 30 Nov 2023 11:28:33 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2023 17:32:23 GMT", "version": "v2" }, { "created": "Fri, 31 May 2024 16:44:18 GMT", "version": "v3" } ]
2024-06-03
[ [ "Ajmal", "Sehar", "" ], [ "Gaglione", "Jethro", "" ], [ "Gurrola", "Alfredo", "" ], [ "Panella", "Orlando", "" ], [ "Presilla", "Matteo", "" ], [ "Romeo", "Francesco", "" ], [ "Sun", "Hao", "" ], [ ...
We present a detailed study concerning a new physics scenario involving four fermion operators of the Nambu-Jona-Lasinio type characterized by a strong-coupling ultraviolet fixed point where composite particles are formed as bound states of elementary fermions at the scale $\Lambda ={\cal O}(\text{TeV})$. After implementing the model in the Universal FeynRules Output format, we focus on the phenomenology of the scalar leptoquarks at the LHC and the High-Luminosity option. Leptoquark particles have undergone extensive scrutiny in the literature and experimental searches, primarily relying on pair production and, more recently, incorporating single, t-channel, and lepton-induced processes. This study marks, for the first time, the examination of these production modes at varying jet multiplicities. Novel mechanisms emerge, enhancing the total production cross-section, especially for leptoquarks couplings to higher fermion generations. A global strategy is devised to capture all final state particles produced in association with leptoquarks or originating from their decay, which we termed ``exclusive'', in an analogy to the nomenclature used in nuclear reactions. The assessment of the significance in current and future LHC runs, focusing on the case of leptoquark coupling to a muon - $\textit{c}$ quark pair, reveals superior sensitivity compared to ongoing searches. Given this heightened discovery potential, we advocate the incorporation of exclusive leptoquark searches in future investigations at the LHC.
hep-ph/0111387
Christian Bauer
Christian W. Bauer, Zoltan Ligeti and Michael Luke
Precision determination of Vub
5 pages, Talk presented by C. W. Bauer at the International Europhysics Conference on High Energy Physics (HEP2001), Budapest, Hungary, July 12-18 2001
null
null
UCSD-PTH 01-22
hep-ph
null
We review how to determine |Vub| from inclusive semileptonic B decay using combined cuts on the leptonic and hadronic invariant masses to eliminate the b -> c background. This leads to a determination of |Vub| with theoretical uncertainty at the 5 -10% level.
[ { "created": "Wed, 28 Nov 2001 22:34:22 GMT", "version": "v1" }, { "created": "Tue, 18 Dec 2001 14:40:17 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bauer", "Christian W.", "" ], [ "Ligeti", "Zoltan", "" ], [ "Luke", "Michael", "" ] ]
We review how to determine |Vub| from inclusive semileptonic B decay using combined cuts on the leptonic and hadronic invariant masses to eliminate the b -> c background. This leads to a determination of |Vub| with theoretical uncertainty at the 5 -10% level.
hep-ph/0203193
U. Meissner
Matthias Frink, Bastian Kubis, Ulf-G. Mei{\ss}ner
Analysis of the pion-kaon sigma-term and related topics
25 pp, 3 figs
Eur.Phys.J.C25:259-276,2002
10.1007/s10052-002-0975-1
FZJ-IKP(TH)-2002-07
hep-ph
null
We calculate the one-loop contributions to the difference \Delta_{\pi K} between the isoscalar on-shell pion-kaon scattering amplitude at the Cheng-Dashen point and the scalar form factor \Gamma_K (2M_\pi^2) in the framework of three flavor chiral perturbation theory. These corrections turn out to be small. This is further sharpened by treating the kaons as heavy fields (two flavor chiral perturbation theory). We also analyze the two-loop corrections to the kaon scalar form factor based on a dispersive technique. We find that these corrections are smaller than in the comparable case of the scalar form factor of the pion. This is related to the weaker final state interactions in the pion-kaon channel.
[ { "created": "Wed, 20 Mar 2002 09:26:57 GMT", "version": "v1" } ]
2009-01-07
[ [ "Frink", "Matthias", "" ], [ "Kubis", "Bastian", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We calculate the one-loop contributions to the difference \Delta_{\pi K} between the isoscalar on-shell pion-kaon scattering amplitude at the Cheng-Dashen point and the scalar form factor \Gamma_K (2M_\pi^2) in the framework of three flavor chiral perturbation theory. These corrections turn out to be small. This is further sharpened by treating the kaons as heavy fields (two flavor chiral perturbation theory). We also analyze the two-loop corrections to the kaon scalar form factor based on a dispersive technique. We find that these corrections are smaller than in the comparable case of the scalar form factor of the pion. This is related to the weaker final state interactions in the pion-kaon channel.
0708.1474
Johannes Bluemlein
Johannes Bl\"umlein
The Status of the Polarized Parton Densities
Proceedings of 15th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2007), Munich, Germany, 16-20 Apr 2007, 6 pages
null
null
DESY 07-114, SFB/CPP-07-48
hep-ph astro-ph hep-ex
null
A survey is given on the present knowledge of the polarized parton distribution functions. We give an outlook for further developments desired both on the theoretical as well on the experimental side to complete the understanding of the spin--structure of nucleons in the future.
[ { "created": "Fri, 10 Aug 2007 15:30:40 GMT", "version": "v1" }, { "created": "Mon, 13 Aug 2007 06:57:28 GMT", "version": "v2" } ]
2007-08-13
[ [ "Blümlein", "Johannes", "" ] ]
A survey is given on the present knowledge of the polarized parton distribution functions. We give an outlook for further developments desired both on the theoretical as well on the experimental side to complete the understanding of the spin--structure of nucleons in the future.
0904.4750
Yue Chongxing
Chong-Xing Yue, Yong-Zhi Wang, Wei Lui, Wei Ma
Pair production of the T-odd leptons at the LHC
12 pages, 2 figures
Europhys.Lett.86:31002,2009
10.1209/0295-5075/86/31002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The T-odd leptons predicted by the littlest $Higgs$ model with T-parity can be pair produced via the subprocesses $gg\to \ell^{+}_{H}\ell^{-}_{H}$, $q\bar{q}\to \ell^{+}_{H}\ell^{-}_{H}$, $\gamma\gamma\to \ell^{+}_{H}\ell^{-}_{H}$ and $ VV \to \ell^{+}_{H}\ell^{-}_{H}$ ($V$=$W$ or $Z$) at the $CERN$ Large Hadron Collider $(LHC)$. We estimate the hadronic production cross sections for all of these processes and give a simply phenomenology analysis. We find that the cross sections for most of the above processes are very small. However, the value of the cross section for the $Drell-Yan$ process $q\bar{q}\to \ell^{+}_{H}\ell^{-}_{H}$ can reach $270fb$.
[ { "created": "Thu, 30 Apr 2009 06:44:52 GMT", "version": "v1" } ]
2009-11-19
[ [ "Yue", "Chong-Xing", "" ], [ "Wang", "Yong-Zhi", "" ], [ "Lui", "Wei", "" ], [ "Ma", "Wei", "" ] ]
The T-odd leptons predicted by the littlest $Higgs$ model with T-parity can be pair produced via the subprocesses $gg\to \ell^{+}_{H}\ell^{-}_{H}$, $q\bar{q}\to \ell^{+}_{H}\ell^{-}_{H}$, $\gamma\gamma\to \ell^{+}_{H}\ell^{-}_{H}$ and $ VV \to \ell^{+}_{H}\ell^{-}_{H}$ ($V$=$W$ or $Z$) at the $CERN$ Large Hadron Collider $(LHC)$. We estimate the hadronic production cross sections for all of these processes and give a simply phenomenology analysis. We find that the cross sections for most of the above processes are very small. However, the value of the cross section for the $Drell-Yan$ process $q\bar{q}\to \ell^{+}_{H}\ell^{-}_{H}$ can reach $270fb$.
1805.00286
Larbi Rahili
M. Chabab, M. C. Peyran\`ere and L. Rahili
Probing the Higgs sector of $Y=0$ Higgs Triplet Model at LHC
33 pages, 12 figures, 1 table, references added, version to be published in Eur. Phys. J. C
null
10.1140/epjc/s10052-018-6339-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we investigate the Higgs Triplet Model with hypercharge $Y_{\Delta}=0$ (HTM0), an extension of the Standard model, caracterised by a more involved scalar spectrum consisting of two CP even Higgs $h^0, H^0$ and two charged Higgs bosons $H^\pm$. We first show that the parameter space of HTM0, usually delimited by combined constraints originating from unitarity and BFB as well as experimental limits from LEP and LHC, is severely reduced when the modified Veltman conditions at one loop are also imposed. Then, we perform an rigorous analysis of Higgs decays either when $h^0$ is the SM-like or when the heaviest neutral Higgs $H^0$ is identified to the observed $125$ GeV Higgs boson at LHC. In these scenarios, we perform an extensive parameter scan, in the lower part of the scalar mass spectrum, with a particular focus on the Higgs to Higgs decay modes $H^0 \to h^0h^0, H^\pm\,H^\mp$ leading predominantly to invisible Higgs decays. Finally, we also study the scenario where $h^0, H^0$ are mass degenerate. We thus find that consistency with LHC signal strengths favours a light charged Higgs with a mass about $176\sim178$ GeV. Our analysis shows that the diphoton Higgs decay mode and $H \to Z \gamma$ are not always positively correlated as claimed in a previous study. Anti-correlation is rather seen in the scenario where $h$ is SM like, while correlation is sensitive to the sign of the potential parameter $\lambda$ when $H$ is identified to $125$ GeV Higgs.
[ { "created": "Tue, 1 May 2018 12:15:17 GMT", "version": "v1" }, { "created": "Fri, 4 May 2018 23:27:17 GMT", "version": "v2" }, { "created": "Tue, 16 Oct 2018 20:20:39 GMT", "version": "v3" } ]
2018-11-14
[ [ "Chabab", "M.", "" ], [ "Peyranère", "M. C.", "" ], [ "Rahili", "L.", "" ] ]
In this paper, we investigate the Higgs Triplet Model with hypercharge $Y_{\Delta}=0$ (HTM0), an extension of the Standard model, caracterised by a more involved scalar spectrum consisting of two CP even Higgs $h^0, H^0$ and two charged Higgs bosons $H^\pm$. We first show that the parameter space of HTM0, usually delimited by combined constraints originating from unitarity and BFB as well as experimental limits from LEP and LHC, is severely reduced when the modified Veltman conditions at one loop are also imposed. Then, we perform an rigorous analysis of Higgs decays either when $h^0$ is the SM-like or when the heaviest neutral Higgs $H^0$ is identified to the observed $125$ GeV Higgs boson at LHC. In these scenarios, we perform an extensive parameter scan, in the lower part of the scalar mass spectrum, with a particular focus on the Higgs to Higgs decay modes $H^0 \to h^0h^0, H^\pm\,H^\mp$ leading predominantly to invisible Higgs decays. Finally, we also study the scenario where $h^0, H^0$ are mass degenerate. We thus find that consistency with LHC signal strengths favours a light charged Higgs with a mass about $176\sim178$ GeV. Our analysis shows that the diphoton Higgs decay mode and $H \to Z \gamma$ are not always positively correlated as claimed in a previous study. Anti-correlation is rather seen in the scenario where $h$ is SM like, while correlation is sensitive to the sign of the potential parameter $\lambda$ when $H$ is identified to $125$ GeV Higgs.
hep-ph/9903489
Andreas Freund
Andreas Freund
Proof of factorization for electroproduction of multiple mesons and exclusive $\gamma^* \gamma$ production of multiple hadrons
16 pages, 5 figures, uses revtex, final version. to be published in Phys. Rev. D
Phys.Rev. D61 (2000) 074010
10.1103/PhysRevD.61.074010
null
hep-ph
null
In the following, we will present a generalization of the proof of factorization for electroproduction of vector mesons to the production of several mesons such as $\pi^+\pi^-$ and a proof of factorization for exclusive $\gamma^* \gamma$ production of several hadrons for example $p \bar p$ or $\pi^+\pi^-$ to all orders in perturbation theory up to power suppressed terms.
[ { "created": "Thu, 25 Mar 1999 11:10:24 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 1999 08:45:34 GMT", "version": "v2" }, { "created": "Fri, 26 Nov 1999 16:34:48 GMT", "version": "v3" } ]
2009-10-31
[ [ "Freund", "Andreas", "" ] ]
In the following, we will present a generalization of the proof of factorization for electroproduction of vector mesons to the production of several mesons such as $\pi^+\pi^-$ and a proof of factorization for exclusive $\gamma^* \gamma$ production of several hadrons for example $p \bar p$ or $\pi^+\pi^-$ to all orders in perturbation theory up to power suppressed terms.
2311.09166
Matthew Low
Kun Cheng, Tao Han, Matthew Low
Optimizing Fictitious States for Bell Inequality Violation in Bipartite Qubit Systems
v2: 6 pages, 1 figure, updated to journal version
Phys.Rev.D 109 (2024) 11, 116005
10.1103/PhysRevD.109.116005
null
hep-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
There is a significant interest in testing quantum entanglement and Bell inequality violation in high-energy experiments. Since the analyses in high-energy experiments are performed with events statistically averaged over phase space, the states used to determine observables depend on the choice of coordinates through an event-dependent basis and are thus not genuine quantum states, but rather "fictitious states." We prove that if Bell inequality violation is observed with a fictitious state, then it implies the same for a quantum sub-state. We further show analytically that the basis which diagonalizes the spin-spin correlations is optimal for constructing fictitious states, and for maximizing the violation of Bell's inequality.
[ { "created": "Wed, 15 Nov 2023 18:05:44 GMT", "version": "v1" }, { "created": "Fri, 7 Jun 2024 11:26:21 GMT", "version": "v2" } ]
2024-06-11
[ [ "Cheng", "Kun", "" ], [ "Han", "Tao", "" ], [ "Low", "Matthew", "" ] ]
There is a significant interest in testing quantum entanglement and Bell inequality violation in high-energy experiments. Since the analyses in high-energy experiments are performed with events statistically averaged over phase space, the states used to determine observables depend on the choice of coordinates through an event-dependent basis and are thus not genuine quantum states, but rather "fictitious states." We prove that if Bell inequality violation is observed with a fictitious state, then it implies the same for a quantum sub-state. We further show analytically that the basis which diagonalizes the spin-spin correlations is optimal for constructing fictitious states, and for maximizing the violation of Bell's inequality.
hep-ph/0606109
Jacques Soffer
Jacques Soffer
New developments in the statistical approach of parton distributions
10 pages, 12 figures. Invited talk presented at the " Corfu Summer Institute on EPP,CORFU2005, Corfu, Greece, September 4-26, 2005. To be published in Journal of Physics, Conference Series (2006)
null
10.1088/1742-6596/53/1/029
CPT-2006/P.012
hep-ph
null
We recall how parton distributions are constructed in a statistical physical picture of the nucleon. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and the importance of the Pauli exclusion principle is also emphasized. A global next-to-leading order QCD analysis of unpolarized and polarized deep-inelastic scattering data allows to determine a small number of free parameters. Some predictions are compared to recent experimental results and we discuss the prospects of this physical framework.
[ { "created": "Fri, 9 Jun 2006 15:44:13 GMT", "version": "v1" } ]
2015-06-25
[ [ "Soffer", "Jacques", "" ] ]
We recall how parton distributions are constructed in a statistical physical picture of the nucleon. The chiral properties of QCD lead to strong relations between quarks and antiquarks distributions and the importance of the Pauli exclusion principle is also emphasized. A global next-to-leading order QCD analysis of unpolarized and polarized deep-inelastic scattering data allows to determine a small number of free parameters. Some predictions are compared to recent experimental results and we discuss the prospects of this physical framework.
hep-ph/0109005
B. L. G. Bakker
B.L.G. Bakker and C.-R. Ji
Frame Dependence of Spin-One Angular Conditions in Light Front Dynamics
29 pages RevTeX. submitted to Phys. Rev. D
Phys.Rev. D65 (2002) 073002
10.1103/PhysRevD.65.073002
null
hep-ph
null
We elaborate the frame dependence of the angular conditions for spin-1 form factors. An extra angular condition is found in addition to the usual angular condition relating the four helicity amplitudes. Investigating the frame-dependence of the angular conditions, we find that the extra angular condition is in general as complicated as the usual one, although it becomes very simple in the $q^+ = 0$ frame involving only two helicity amplitudes. It is confirmed that the angular conditions are identical in frames that are connected by kinematical transformations. The high $Q^2$ behaviors of the physical form factors and the limiting behaviors in special reference frames are also discussed.
[ { "created": "Sun, 2 Sep 2001 07:51:54 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bakker", "B. L. G.", "" ], [ "Ji", "C. -R.", "" ] ]
We elaborate the frame dependence of the angular conditions for spin-1 form factors. An extra angular condition is found in addition to the usual angular condition relating the four helicity amplitudes. Investigating the frame-dependence of the angular conditions, we find that the extra angular condition is in general as complicated as the usual one, although it becomes very simple in the $q^+ = 0$ frame involving only two helicity amplitudes. It is confirmed that the angular conditions are identical in frames that are connected by kinematical transformations. The high $Q^2$ behaviors of the physical form factors and the limiting behaviors in special reference frames are also discussed.
hep-ph/0512154
Kyle S. Cranmer
Kyle S. Cranmer
Potential for Higgs Physics at the LHC and Super-LHC
Invited talk at 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO(Snowmass05) 3 pages, 0 figures. PSN ALCPG0602
null
null
null
hep-ph
null
The expected sensitivity of the LHC experiments to the discovery of the Higgs boson and the measurement of its properties is presented in the context of both the standard model and the its minimal supersymmetric extension. Prospects for a luminosity-upgraded ``Super-LHC'' are also presented.
[ { "created": "Mon, 12 Dec 2005 20:37:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cranmer", "Kyle S.", "" ] ]
The expected sensitivity of the LHC experiments to the discovery of the Higgs boson and the measurement of its properties is presented in the context of both the standard model and the its minimal supersymmetric extension. Prospects for a luminosity-upgraded ``Super-LHC'' are also presented.
1304.2113
Raghunath Sahoo
Raghunath Sahoo and Aditya Nath Mishra (Indian Institute of Technology Indore, India)
Transverse energy and charged particle production in heavy-ion collisions: From RHIC to LHC
19 pages, 7 figures
International Journal of Modern Physics E, Vol. 23, No. 4 (2014) 1450024 (19 pages)
10.1142/S0218301314500244
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the charged particle and transverse energy production mechanism from AGS, SPS, RHIC to LHC energies in the framework of nucleon and quark participants. At RHIC and LHC energies, the number of nucleons-normalized charged particle and transverse energy density in pseudorapidity, which shows a monotonic rise with centrality, turns out to be an almost centrality independent scaling behaviour when normalized to the number of participant quarks. A universal function which is a combination of logarithmic and power-law, describes well the charged particle and transverse energy production both at nucleon and quark participant level for the whole range of collision energies. Energy dependent production mechanisms are discussed both for nucleonic and partonic level. Predictions are made for the pseudorapidity densities of transverse energy, charged particle multiplicity and their ratio (the barometric observable, $\frac{dE_{\rm{T}}/d\eta}{dN_{\rm{ch}}/d\eta} ~\equiv \frac{E_{\rm{T}}}{N_{\rm{ch}}}$) at mid-rapidity for Pb+Pb collisions at $\sqrt{s_{\rm{NN}}}=5.5$ TeV. A comparison with models based on gluon saturation and statistical hadron gas is made for the energy dependence of $\frac{E_{\rm{T}}}{N_{\rm{ch}}}$.
[ { "created": "Mon, 8 Apr 2013 06:38:24 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2013 11:26:50 GMT", "version": "v2" }, { "created": "Wed, 30 Apr 2014 11:10:43 GMT", "version": "v3" } ]
2014-05-01
[ [ "Sahoo", "Raghunath", "", "Indian Institute of Technology\n Indore, India" ], [ "Mishra", "Aditya Nath", "", "Indian Institute of Technology\n Indore, India" ] ]
We study the charged particle and transverse energy production mechanism from AGS, SPS, RHIC to LHC energies in the framework of nucleon and quark participants. At RHIC and LHC energies, the number of nucleons-normalized charged particle and transverse energy density in pseudorapidity, which shows a monotonic rise with centrality, turns out to be an almost centrality independent scaling behaviour when normalized to the number of participant quarks. A universal function which is a combination of logarithmic and power-law, describes well the charged particle and transverse energy production both at nucleon and quark participant level for the whole range of collision energies. Energy dependent production mechanisms are discussed both for nucleonic and partonic level. Predictions are made for the pseudorapidity densities of transverse energy, charged particle multiplicity and their ratio (the barometric observable, $\frac{dE_{\rm{T}}/d\eta}{dN_{\rm{ch}}/d\eta} ~\equiv \frac{E_{\rm{T}}}{N_{\rm{ch}}}$) at mid-rapidity for Pb+Pb collisions at $\sqrt{s_{\rm{NN}}}=5.5$ TeV. A comparison with models based on gluon saturation and statistical hadron gas is made for the energy dependence of $\frac{E_{\rm{T}}}{N_{\rm{ch}}}$.
hep-ph/0604071
Omar Benhar
Omar Benhar, Davide Meloni
Estimates of the uncertainties associated with models of the nucleon structure functions in the $\Delta$ production region
Accepted for publication in Physical Review Letters
Phys.Rev.Lett.97:192301,2006
10.1103/PhysRevLett.97.192301
null
hep-ph
null
Theoretical studies of the inclusive electron-nucleus cross section at beam energies up to few GeV show that, while the region of the quasi-elastic peak is understood at quantitative level, the data in the $\Delta$ production region are sizably underestimated. We analize the uncertainty associated with the description of the nucleon structure functions $W_1$ and $W_2$ and its impact on the nuclear cross section. The results of our study suggest that the failure to reproduce the data is to be mostly ascribed to the poor knowledge of the neutron structure functions at low $Q^2$.
[ { "created": "Fri, 7 Apr 2006 11:04:03 GMT", "version": "v1" }, { "created": "Fri, 6 Oct 2006 07:01:26 GMT", "version": "v2" } ]
2008-11-26
[ [ "Benhar", "Omar", "" ], [ "Meloni", "Davide", "" ] ]
Theoretical studies of the inclusive electron-nucleus cross section at beam energies up to few GeV show that, while the region of the quasi-elastic peak is understood at quantitative level, the data in the $\Delta$ production region are sizably underestimated. We analize the uncertainty associated with the description of the nucleon structure functions $W_1$ and $W_2$ and its impact on the nuclear cross section. The results of our study suggest that the failure to reproduce the data is to be mostly ascribed to the poor knowledge of the neutron structure functions at low $Q^2$.
2112.12568
Johannes Roth
Johannes V. Roth, Dominik Schweitzer, Leon J. Sieke, and Lorenz von Smekal
Real-time methods for spectral functions
35 pages, 8 figures, revised version accepted for publication in PRD
null
10.1103/PhysRevD.105.116017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we develop and compare different real-time methods to calculate spectral functions. These are classical-statistical simulations, the Gaussian state approximation (GSA), and the functional renormalization group (FRG) formulated on the Keldysh closed-time path. Our test-bed system is the quartic anharmonic oscillator, a single self-interacting bosonic degree of freedom, coupled to an external heat bath providing dissipation analogous to the Caldeira-Leggett model. As our benchmark we use the spectral function from exact diagonalization with constant Ohmic damping. To extend the GSA for the open system, we solve the corresponding Heisenberg-Langevin equations in the Gaussian approximation. For the real-time FRG, we introduce a novel general prescription to construct causal regulators based on introducing scale-dependent fictitious heat baths. Our results explicitly demonstrate how the discrete transition lines of the quantum system gradually build up the broad continuous structures in the classical spectral function as temperature increases. At sufficiently high temperatures, classical, GSA and exact-diagonalization results all coincide. The real-time FRG is able to reproduce the effective thermal mass, but overestimates broadening and only qualitatively describes higher excitations, at the present order of our combined vertex and loop expansion. As temperature is lowered, the GSA follows the ensemble average of the exact solution better than the classical spectral function. In the low-temperature strong-coupling regime, the qualitative features of the exact result are best captured by our real-time FRG calculation, with quantitative improvements to be expected at higher truncation orders.
[ { "created": "Thu, 23 Dec 2021 14:29:27 GMT", "version": "v1" }, { "created": "Fri, 7 Jan 2022 14:29:23 GMT", "version": "v2" }, { "created": "Tue, 31 May 2022 15:31:18 GMT", "version": "v3" } ]
2022-06-23
[ [ "Roth", "Johannes V.", "" ], [ "Schweitzer", "Dominik", "" ], [ "Sieke", "Leon J.", "" ], [ "von Smekal", "Lorenz", "" ] ]
In this paper we develop and compare different real-time methods to calculate spectral functions. These are classical-statistical simulations, the Gaussian state approximation (GSA), and the functional renormalization group (FRG) formulated on the Keldysh closed-time path. Our test-bed system is the quartic anharmonic oscillator, a single self-interacting bosonic degree of freedom, coupled to an external heat bath providing dissipation analogous to the Caldeira-Leggett model. As our benchmark we use the spectral function from exact diagonalization with constant Ohmic damping. To extend the GSA for the open system, we solve the corresponding Heisenberg-Langevin equations in the Gaussian approximation. For the real-time FRG, we introduce a novel general prescription to construct causal regulators based on introducing scale-dependent fictitious heat baths. Our results explicitly demonstrate how the discrete transition lines of the quantum system gradually build up the broad continuous structures in the classical spectral function as temperature increases. At sufficiently high temperatures, classical, GSA and exact-diagonalization results all coincide. The real-time FRG is able to reproduce the effective thermal mass, but overestimates broadening and only qualitatively describes higher excitations, at the present order of our combined vertex and loop expansion. As temperature is lowered, the GSA follows the ensemble average of the exact solution better than the classical spectral function. In the low-temperature strong-coupling regime, the qualitative features of the exact result are best captured by our real-time FRG calculation, with quantitative improvements to be expected at higher truncation orders.
hep-ph/9912306
Peter Arnold
Peter Arnold and Laurence G. Yaffe
High temperature color conductivity at next-to-leading log order
47 pages, 6+2 figures
Phys.Rev.D62:125014,2000
10.1103/PhysRevD.62.125014
UW/PT 99-24
hep-ph
null
The non-Abelian analog of electrical conductivity at high temperature has previously been known only at leading logarithmic order: that is, neglecting effects suppressed only by an inverse logarithm of the gauge coupling. We calculate the first sub-leading correction. This has immediate application to improving, to next-to-leading log order, both effective theories of non-perturbative color dynamics, and calculations of the hot electroweak baryon number violation rate.
[ { "created": "Fri, 10 Dec 1999 22:38:25 GMT", "version": "v1" } ]
2010-02-16
[ [ "Arnold", "Peter", "" ], [ "Yaffe", "Laurence G.", "" ] ]
The non-Abelian analog of electrical conductivity at high temperature has previously been known only at leading logarithmic order: that is, neglecting effects suppressed only by an inverse logarithm of the gauge coupling. We calculate the first sub-leading correction. This has immediate application to improving, to next-to-leading log order, both effective theories of non-perturbative color dynamics, and calculations of the hot electroweak baryon number violation rate.
1703.02122
Marcin Badziak
Marcin Badziak and Keisuke Harigaya
Supersymmetric D-term Twin Higgs
27 pages, 5 figures; v2: appendix extended, matches version published in JHEP
null
10.1007/JHEP06(2017)065
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new type of supersymmetric Twin Higgs model where the SU(4) invariant quartic term is provided by a D-term potential of a new U(1) gauge symmetry. In the model the 125 GeV Higgs mass can be obtained for stop masses below 1 TeV, and a tuning required to obtain the correct electroweak scale can be as low as 20 %. A stop mass of about 2 TeV is also possible with tuning of order O(10) %.
[ { "created": "Mon, 6 Mar 2017 21:46:51 GMT", "version": "v1" }, { "created": "Wed, 1 Nov 2017 04:50:24 GMT", "version": "v2" } ]
2017-11-02
[ [ "Badziak", "Marcin", "" ], [ "Harigaya", "Keisuke", "" ] ]
We propose a new type of supersymmetric Twin Higgs model where the SU(4) invariant quartic term is provided by a D-term potential of a new U(1) gauge symmetry. In the model the 125 GeV Higgs mass can be obtained for stop masses below 1 TeV, and a tuning required to obtain the correct electroweak scale can be as low as 20 %. A stop mass of about 2 TeV is also possible with tuning of order O(10) %.
hep-ph/0504179
Celso de Camargo Barros Barros
Celso de Camargo Barros Jr
Quark confinement and curved spaces
null
Eur.Phys.J.C45:421-425,2006
10.1140/epjc/s2005-02431-6
null
hep-ph
null
In this work it will be shown how quark confinement appears when wave equations derived in curved spaces are considered. First, the equations and their solutions for Coulomb-like potentials will be presented, and then, how this theory leads to quark confinement. A comparison between different models of confinement will be also made.
[ { "created": "Wed, 20 Apr 2005 18:06:45 GMT", "version": "v1" } ]
2009-01-07
[ [ "Barros", "Celso de Camargo", "Jr" ] ]
In this work it will be shown how quark confinement appears when wave equations derived in curved spaces are considered. First, the equations and their solutions for Coulomb-like potentials will be presented, and then, how this theory leads to quark confinement. A comparison between different models of confinement will be also made.
1304.4087
Miguel Angel Escobedo Espinosa
Miguel Angel Escobedo, Floriana Giannuzzi, Massimo Mannarelli and Joan Soto
Heavy Quarkonium moving in a Quark-Gluon Plasma
Published version, title changed and improved bibliography, 21 pages. 8 figures
Physical Review D 87, 114005 (2013)
10.1103/PhysRevD.87.114005
UB-ECM-PF-13/88, ICCUB-13-064, BARI-TH/13-674, TUM-EFT35/12
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By means of effective field theory techniques, we study the modifications of some properties of weakly coupled heavy quarkonium states propagating through a quark-gluon plasma at temperatures much smaller than the heavy quark mass, m_Q. Two different cases are considered, corresponding to two different hierarchies between the typical size of the bound state, r, the binding energy, E, the temperature, T, and the screening mass, m_D. The first case corresponds to the hierarchy m_Q >> 1/r >> T >> E >> m_D, relevant for moderate temperatures, and the second one to the hierarchy m_Q >> T >> 1/r, m_D >> E, relevant for studying the dissociation mechanism. In the first case we determine the perturbative correction to the binding energy and to the decay width of states with arbitrary angular momentum, finding that the width is a decreasing function of the velocity. A different behavior characterizes the second kinematical case, being the width of s-wave states a non-monotonic function of the velocity, increasing at moderate velocities and decreasing in the ultra-relativistic limit. We obtain a simple analytical expression of the decay width for T >> 1/r >> m_D >> E at moderate velocities, and we derive the s-wave spectral function for the more general case T >> 1/r, m_D >> E. A brief discussion of the possible experimental signatures as well as a comparison with the relevant lattice data are also presented.
[ { "created": "Mon, 15 Apr 2013 13:15:17 GMT", "version": "v1" }, { "created": "Thu, 27 Jun 2013 07:46:04 GMT", "version": "v2" } ]
2013-06-28
[ [ "Escobedo", "Miguel Angel", "" ], [ "Giannuzzi", "Floriana", "" ], [ "Mannarelli", "Massimo", "" ], [ "Soto", "Joan", "" ] ]
By means of effective field theory techniques, we study the modifications of some properties of weakly coupled heavy quarkonium states propagating through a quark-gluon plasma at temperatures much smaller than the heavy quark mass, m_Q. Two different cases are considered, corresponding to two different hierarchies between the typical size of the bound state, r, the binding energy, E, the temperature, T, and the screening mass, m_D. The first case corresponds to the hierarchy m_Q >> 1/r >> T >> E >> m_D, relevant for moderate temperatures, and the second one to the hierarchy m_Q >> T >> 1/r, m_D >> E, relevant for studying the dissociation mechanism. In the first case we determine the perturbative correction to the binding energy and to the decay width of states with arbitrary angular momentum, finding that the width is a decreasing function of the velocity. A different behavior characterizes the second kinematical case, being the width of s-wave states a non-monotonic function of the velocity, increasing at moderate velocities and decreasing in the ultra-relativistic limit. We obtain a simple analytical expression of the decay width for T >> 1/r >> m_D >> E at moderate velocities, and we derive the s-wave spectral function for the more general case T >> 1/r, m_D >> E. A brief discussion of the possible experimental signatures as well as a comparison with the relevant lattice data are also presented.
1410.5908
Jong-Chul Park
Jong-Chul Park, Seong Chan Park
Superheavy Dark Matter in Light of Dark Radiation
7 pages, 2 figures; published in JKPS
J. Korean Phys. Soc. 65 (2014) No. 6, 805
10.3938/jkps.65.805
null
hep-ph astro-ph.CO astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Superheavy dark matter can satisfy the observed dark matter abundance if the stability condition is fulfilled. Here, we propose a new Abelian gauge symmetry ${\rm U(1)}_H$ for the stability of superheavy dark matter as the electromagnetic gauge symmetry to the electron. The new gauge boson associated with ${\rm U(1)}_H$ contributes to the effective number of relativistic degrees of freedom in the universe as dark radiation, which has been recently measured by several experiments, e.g., PLANCK. We calculate the contribution to dark radiation from the decay of a scalar particle via the superheavy dark matter in the loop. Interestingly enough, this scenario will be probed by a future LHC run in the invisible decay signatures of the Higgs boson.
[ { "created": "Wed, 22 Oct 2014 03:45:46 GMT", "version": "v1" } ]
2015-06-23
[ [ "Park", "Jong-Chul", "" ], [ "Park", "Seong Chan", "" ] ]
Superheavy dark matter can satisfy the observed dark matter abundance if the stability condition is fulfilled. Here, we propose a new Abelian gauge symmetry ${\rm U(1)}_H$ for the stability of superheavy dark matter as the electromagnetic gauge symmetry to the electron. The new gauge boson associated with ${\rm U(1)}_H$ contributes to the effective number of relativistic degrees of freedom in the universe as dark radiation, which has been recently measured by several experiments, e.g., PLANCK. We calculate the contribution to dark radiation from the decay of a scalar particle via the superheavy dark matter in the loop. Interestingly enough, this scenario will be probed by a future LHC run in the invisible decay signatures of the Higgs boson.
hep-ph/9809515
Kingman Cheung
Kingman Cheung (UC-Davis)
A monte carlo study of the rare decay $B \to X_s \ell^+ \ell^-$
9 pages, 6 figures
Phys.Rev. D59 (1999) 097501
10.1103/PhysRevD.59.097501
UCD-98-16
hep-ph
null
We study, using a monte carlo approach, the rare decay $B\to X_s \ell^+ \ell^-$ including effects of the arbitrariness of the phase between the $\psi$ amplitudes and the perturbative amplitude, $b$-quark fermi motion inside the $B$ meson, and experimental smearing of lepton momenta. The fermi motion of $b$-quark inside the $B$ meson is modeled by the ACCMM model. We found that such effects reduce the sensitivities of the spectra of invariant mass and forward-backward asymmetry of the lepton pair to new physics; especially, in the neighborhood of the $\psi$ resonances. We also estimate the sensitivity range of Wilson coefficients with respect to the uncertainties.
[ { "created": "Thu, 24 Sep 1998 00:39:15 GMT", "version": "v1" } ]
2009-10-31
[ [ "Cheung", "Kingman", "", "UC-Davis" ] ]
We study, using a monte carlo approach, the rare decay $B\to X_s \ell^+ \ell^-$ including effects of the arbitrariness of the phase between the $\psi$ amplitudes and the perturbative amplitude, $b$-quark fermi motion inside the $B$ meson, and experimental smearing of lepton momenta. The fermi motion of $b$-quark inside the $B$ meson is modeled by the ACCMM model. We found that such effects reduce the sensitivities of the spectra of invariant mass and forward-backward asymmetry of the lepton pair to new physics; especially, in the neighborhood of the $\psi$ resonances. We also estimate the sensitivity range of Wilson coefficients with respect to the uncertainties.
1807.00629
Ricardo Cepedello
Ricardo Cepedello, Renato M. Fonseca, Martin Hirsch
Systematic classification of three-loop realizations of the Weinberg operator
Erratum added, published version in JHEP
JHEP1810(2018)197; JHEP1906(2019)034
10.1007/JHEP10(2018)197; 10.1007/JHEP06(2019)034
IFIC/18-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study systematically the decomposition of the Weinberg operator at three-loop order. There are more than four thousand connected topologies. However, the vast majority of these are infinite corrections to lower order neutrino mass diagrams and only a very small percentage yields models for which the three-loop diagrams are the leading order contribution to the neutrino mass matrix. We identify 73 topologies that can lead to genuine three-loop models with fermions and scalars, i.e. models for which lower order diagrams are automatically absent without the need to invoke additional symmetries. The 73 genuine topologies can be divided into two sub-classes: Normal genuine ones (44 cases) and special genuine topologies (29 cases). The latter are a special class of topologies, which can lead to genuine diagrams only for very specific choices of fields. The genuine topologies generate 374 diagrams in the weak basis, which can be reduced to only 30 distinct diagrams in the mass eigenstate basis. We also discuss how all the mass eigenstate diagrams can be described in terms of only five master integrals. We present some concrete models and for two of them we give numerical estimates for the typical size of neutrino masses they generate. Our results can be readily applied to construct other $d=5$ neutrino mass models with three loops.
[ { "created": "Mon, 2 Jul 2018 12:35:31 GMT", "version": "v1" }, { "created": "Thu, 1 Nov 2018 18:11:50 GMT", "version": "v2" }, { "created": "Tue, 18 Jun 2019 15:29:04 GMT", "version": "v3" } ]
2019-06-19
[ [ "Cepedello", "Ricardo", "" ], [ "Fonseca", "Renato M.", "" ], [ "Hirsch", "Martin", "" ] ]
We study systematically the decomposition of the Weinberg operator at three-loop order. There are more than four thousand connected topologies. However, the vast majority of these are infinite corrections to lower order neutrino mass diagrams and only a very small percentage yields models for which the three-loop diagrams are the leading order contribution to the neutrino mass matrix. We identify 73 topologies that can lead to genuine three-loop models with fermions and scalars, i.e. models for which lower order diagrams are automatically absent without the need to invoke additional symmetries. The 73 genuine topologies can be divided into two sub-classes: Normal genuine ones (44 cases) and special genuine topologies (29 cases). The latter are a special class of topologies, which can lead to genuine diagrams only for very specific choices of fields. The genuine topologies generate 374 diagrams in the weak basis, which can be reduced to only 30 distinct diagrams in the mass eigenstate basis. We also discuss how all the mass eigenstate diagrams can be described in terms of only five master integrals. We present some concrete models and for two of them we give numerical estimates for the typical size of neutrino masses they generate. Our results can be readily applied to construct other $d=5$ neutrino mass models with three loops.
2011.06609
Salvador Centelles Chuli\'a
Salvador Centelles Chuli\'a, Rahul Srivastava and Avelino Vicente
The Inverse Seesaw Family: Dirac And Majorana
32 pages, 11 tables, 8 figures
null
null
IFIC/20-47
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking "$\mu$-terms". These models can be tested both in colliders and with the observation of lepton flavour violating processes.
[ { "created": "Thu, 12 Nov 2020 19:00:14 GMT", "version": "v1" } ]
2020-11-16
[ [ "Chuliá", "Salvador Centelles", "" ], [ "Srivastava", "Rahul", "" ], [ "Vicente", "Avelino", "" ] ]
After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking "$\mu$-terms". These models can be tested both in colliders and with the observation of lepton flavour violating processes.
hep-ph/9709411
Jonathan Feng
Jonathan L. Feng, Takeo Moroi, Hitoshi Murayama, Erhard Schnapka
Third Generation Familons, B Factories, and Neutrino Cosmology
ReVTeX, 33 pages, 6 figures, notation improved, references added, revised to conform to pubished version
Phys. Rev. D 57, 5875 (1998)
10.1103/PhysRevD.57.5875
LBNL-40822, UCB-PTH-97/47
hep-ph astro-ph hep-ex
null
We study the physics of spontaneously broken family symmetries acting on the third generation. Massless familons (or Majorons) $f$ associated with such broken symmetries are motivated especially by cosmological scenarios with decaying tau neutrinos. We first note that, in marked contrast with the case for the first two generations, constraints on third generation familon couplings are poor, and are, in fact, non-existent at present in the hadronic sector. We derive new bounds from $B^0$--$\bar{B}^0$ mixing, $B^0 \to l^+ l'^-$, $b\to s\nu\bar{\nu}$, and astrophysics. The resulting constraints on familon decay constants are still much weaker than those for the first and second generation. We then discuss the promising prospects for significant improvements from searches for $\tau\to l f$, $B\to (\pi, K) f$, and $b\to (d,s) f$ with the current CLEO, ARGUS, and LEP data. Finally, we note that future constraints from CLEO III and the $B$ factories will probe decay constants beyond 10^8 GeV, well within regions of parameter space favored by proposed scenarios in neutrino cosmology.
[ { "created": "Sat, 20 Sep 1997 01:49:47 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 1997 01:59:01 GMT", "version": "v2" }, { "created": "Tue, 17 Feb 1998 02:05:11 GMT", "version": "v3" } ]
2016-08-25
[ [ "Feng", "Jonathan L.", "" ], [ "Moroi", "Takeo", "" ], [ "Murayama", "Hitoshi", "" ], [ "Schnapka", "Erhard", "" ] ]
We study the physics of spontaneously broken family symmetries acting on the third generation. Massless familons (or Majorons) $f$ associated with such broken symmetries are motivated especially by cosmological scenarios with decaying tau neutrinos. We first note that, in marked contrast with the case for the first two generations, constraints on third generation familon couplings are poor, and are, in fact, non-existent at present in the hadronic sector. We derive new bounds from $B^0$--$\bar{B}^0$ mixing, $B^0 \to l^+ l'^-$, $b\to s\nu\bar{\nu}$, and astrophysics. The resulting constraints on familon decay constants are still much weaker than those for the first and second generation. We then discuss the promising prospects for significant improvements from searches for $\tau\to l f$, $B\to (\pi, K) f$, and $b\to (d,s) f$ with the current CLEO, ARGUS, and LEP data. Finally, we note that future constraints from CLEO III and the $B$ factories will probe decay constants beyond 10^8 GeV, well within regions of parameter space favored by proposed scenarios in neutrino cosmology.
1903.11911
Shuntaro Sakai
J. Nieves, R. Pavao, S. Sakai
$\Lambda_b$ decays into $\Lambda_c^*\ell\bar{\nu}_\ell$ and $\Lambda_c^*\pi^-$ $[\Lambda_c^*=\Lambda_c(2595)$ \& $\Lambda_c(2625)]$ and heavy quark spin symmetry
22 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the implications for $\Lambda_b \to \Lambda_c^*\ell\bar{\nu}_\ell$ and $\Lambda_b \to \Lambda_c^*\pi^-$ $[\Lambda_c^*=\Lambda_c(2595)$ and $\Lambda_c(2625)]$ decays that can be deduced from heavy quark spin symmetry (HQSS). Identifying the odd parity $\Lambda_c(2595)$ and $\Lambda_c(2625)$ resonances as HQSS partners, with total angular momentum--parity $j_q^P=1^-$ for the light degrees of freedom, we find that the ratios $\Gamma(\Lambda_b\rightarrow\Lambda_c(2595)\pi^-)/\Gamma(\Lambda_b\rightarrow\Lambda_c(2625)\pi^-)$ and $\Gamma(\Lambda_b\rightarrow \Lambda_c(2595) \ell \bar{\nu}_\ell)/ \Gamma(\Lambda_b\rightarrow\Lambda_c(2625) \ell \bar{\nu}_\ell)$ agree, within errors, with the experimental values given in the Review of Particle Physics. We discuss how future, and more precise, measurements of the above branching fractions could be used to shed light into the inner HQSS structure of the narrow $\Lambda_c(2595)$ odd-parity resonance. Namely, we show that such studies would constrain the existence of a sizable $j^P_q=0^-$ component in its wave-function, and/or of a two-pole pattern, in analogy to the case of the similar $\Lambda(1405)$ resonance in the strange sector, as suggested by most of the approaches that describe the $\Lambda_c(2595)$ as a hadron molecule. We also investigate the lepton flavor universality ratios $R[\Lambda_c^*] = {\cal B}(\Lambda_b \to \Lambda_c^* \tau\,\bar\nu_\tau)/{\cal B}(\Lambda_b \to \Lambda_c^* \mu\,\bar\nu_\mu)$, and discuss how $R[\Lambda_c(2595)]$ may be affected by a new source of potentially large systematic errors if there are two $\Lambda_c(2595)$ poles.
[ { "created": "Thu, 28 Mar 2019 12:16:43 GMT", "version": "v1" }, { "created": "Mon, 27 May 2019 11:36:51 GMT", "version": "v2" } ]
2019-05-28
[ [ "Nieves", "J.", "" ], [ "Pavao", "R.", "" ], [ "Sakai", "S.", "" ] ]
We study the implications for $\Lambda_b \to \Lambda_c^*\ell\bar{\nu}_\ell$ and $\Lambda_b \to \Lambda_c^*\pi^-$ $[\Lambda_c^*=\Lambda_c(2595)$ and $\Lambda_c(2625)]$ decays that can be deduced from heavy quark spin symmetry (HQSS). Identifying the odd parity $\Lambda_c(2595)$ and $\Lambda_c(2625)$ resonances as HQSS partners, with total angular momentum--parity $j_q^P=1^-$ for the light degrees of freedom, we find that the ratios $\Gamma(\Lambda_b\rightarrow\Lambda_c(2595)\pi^-)/\Gamma(\Lambda_b\rightarrow\Lambda_c(2625)\pi^-)$ and $\Gamma(\Lambda_b\rightarrow \Lambda_c(2595) \ell \bar{\nu}_\ell)/ \Gamma(\Lambda_b\rightarrow\Lambda_c(2625) \ell \bar{\nu}_\ell)$ agree, within errors, with the experimental values given in the Review of Particle Physics. We discuss how future, and more precise, measurements of the above branching fractions could be used to shed light into the inner HQSS structure of the narrow $\Lambda_c(2595)$ odd-parity resonance. Namely, we show that such studies would constrain the existence of a sizable $j^P_q=0^-$ component in its wave-function, and/or of a two-pole pattern, in analogy to the case of the similar $\Lambda(1405)$ resonance in the strange sector, as suggested by most of the approaches that describe the $\Lambda_c(2595)$ as a hadron molecule. We also investigate the lepton flavor universality ratios $R[\Lambda_c^*] = {\cal B}(\Lambda_b \to \Lambda_c^* \tau\,\bar\nu_\tau)/{\cal B}(\Lambda_b \to \Lambda_c^* \mu\,\bar\nu_\mu)$, and discuss how $R[\Lambda_c(2595)]$ may be affected by a new source of potentially large systematic errors if there are two $\Lambda_c(2595)$ poles.
1002.0692
Shaaban Khalil
Shaaban Khalil, Hye-Sung Lee, and Ernest Ma
Bound on Z' Mass from CDMS II in the Dark Left-Right Gauge Model II
11 pages
Phys.Rev.D81:051702,2010
10.1103/PhysRevD.81.051702
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the recent possible signal of dark matter from the CDMS II experiment, the Z' mass of a new version of the dark left-right gauge model (DLRM II) is predicted to be at around a TeV. As such, it has an excellent discovery prognosis at the operating Large Hadron Collider.
[ { "created": "Wed, 3 Feb 2010 10:14:45 GMT", "version": "v1" } ]
2014-11-20
[ [ "Khalil", "Shaaban", "" ], [ "Lee", "Hye-Sung", "" ], [ "Ma", "Ernest", "" ] ]
With the recent possible signal of dark matter from the CDMS II experiment, the Z' mass of a new version of the dark left-right gauge model (DLRM II) is predicted to be at around a TeV. As such, it has an excellent discovery prognosis at the operating Large Hadron Collider.
hep-ph/0211343
Erhan Iltan
E. Iltan (METU, Ankara), H. Sundu (METU, Ankara)
H^+ -> W^+ l_i^- l_j^+$ decay in the two Higgs doublet model
8 pages, 7 Figures
Phys.Rev.D67:035006,2003
10.1103/PhysRevD.67.035006
null
hep-ph
null
We study the lepton flavor violating H^+ -> W^+ l_i^- l_j^+ and the lepton flavor conserving $H^+ -> W^+ l_i^- l_i^+ (l_i=\tau, l_j=\mu) decays in the general 2HDM, so called model III. We estimate the decay width \Gamma for LFV (LFC) at the order of the magnitude of (10^{-11}-10^{-5}) GeV ((10^{-9}-10^{-4}) GeV), for 200 GeV\leq m_{H^\pm}\leq 400 GeV, and the intermediate values of the coupling \bar{\xi}^{E}_{N,\tau \mu}\sim 5 GeV (\bar{\xi}^{E}_{N,\tau \tau}\sim 30 GeV). We observe that the experimental result of the process under consideration can give comprehensive information about the physics beyond the standard model and the existing free parameters.
[ { "created": "Thu, 21 Nov 2002 21:48:06 GMT", "version": "v1" }, { "created": "Thu, 30 Jan 2003 10:24:02 GMT", "version": "v2" } ]
2011-03-23
[ [ "Iltan", "E.", "", "METU, Ankara" ], [ "Sundu", "H.", "", "METU, Ankara" ] ]
We study the lepton flavor violating H^+ -> W^+ l_i^- l_j^+ and the lepton flavor conserving $H^+ -> W^+ l_i^- l_i^+ (l_i=\tau, l_j=\mu) decays in the general 2HDM, so called model III. We estimate the decay width \Gamma for LFV (LFC) at the order of the magnitude of (10^{-11}-10^{-5}) GeV ((10^{-9}-10^{-4}) GeV), for 200 GeV\leq m_{H^\pm}\leq 400 GeV, and the intermediate values of the coupling \bar{\xi}^{E}_{N,\tau \mu}\sim 5 GeV (\bar{\xi}^{E}_{N,\tau \tau}\sim 30 GeV). We observe that the experimental result of the process under consideration can give comprehensive information about the physics beyond the standard model and the existing free parameters.
hep-ph/0610111
Peter Levai
G. Fai, P. Levai, G. Papp
From di-hadron correlations to parton intrinsic transverse momentum in proton-proton collisions
Talk given at 2nd International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2006), Asilomar, Pacific Grove, California, 9-16 Jun 2006
Nucl.Phys.A783:535-538,2007
10.1016/j.nuclphysa.2006.11.017
null
hep-ph
null
Di-hadron correlations in proton-proton collisions at s^1/2 = 200 GeV are interpreted in terms of a fragmentation width and a momentum imbalance. A fragmentation width of 580 +- 50 GeV/c is obtained, and the momentum imbalance gives an `intrinsic' transverse momentum width of partons in the proton of 2.6 +- 0.2 GeV/c.
[ { "created": "Tue, 10 Oct 2006 16:00:32 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fai", "G.", "" ], [ "Levai", "P.", "" ], [ "Papp", "G.", "" ] ]
Di-hadron correlations in proton-proton collisions at s^1/2 = 200 GeV are interpreted in terms of a fragmentation width and a momentum imbalance. A fragmentation width of 580 +- 50 GeV/c is obtained, and the momentum imbalance gives an `intrinsic' transverse momentum width of partons in the proton of 2.6 +- 0.2 GeV/c.
1803.00234
Hayato Ito
Hayato Ito, Osamu Jinnouchi, Takeo Moroi, Natsumi Nagata, and Hidetoshi Otono
Searching for Metastable Particles with Sub-Millimeter Displaced Vertices at Hadron Colliders
55 pages, 24 figures
null
10.1007/JHEP06(2018)112
UT-18-03, KYUSHU-RCAPP-2018-01
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A variety of new-physics models predict metastable particles whose decay length is $\lesssim 1$ mm. Conventional displaced-vertex searches are less sensitive to this sub-millimeter decay range, and thus such metastable particles have been looked for only in usual prompt decay searches. In this paper, we show that an additional event-selection cut based on the vertex reconstruction using charged tracks considerably improves the sensitivity of ordinary searches which rely only on kinematic selection criteria, for particles with a decay length of $\gtrsim 100$ $\mu \text{m}$. To that end, we consider a metastable gluino as an example, and study the impact of this new event-selection cut on gluino searches at the LHC by simulating both the signal and Standard Model background processes. Uncertainty of the displaced-vertex reconstruction due to the limited resolution of track reconstruction is taken into account. We also discuss possibilities for optimization of the kinematic selection criteria, which takes advantage of significant reduction of background through the requirement of displaced vertices. In addition, we demonstrate that using the method discussed in this paper it is possible to measure the lifetime of metastable particles with an ${\cal O}(1)$ accuracy at the high-luminosity LHC. Implications for a future 100 TeV collider are also studied, where produced particles tend to be more boosted and thus it is easier to detect the longevity of metastable particles.
[ { "created": "Thu, 1 Mar 2018 07:30:36 GMT", "version": "v1" } ]
2018-08-01
[ [ "Ito", "Hayato", "" ], [ "Jinnouchi", "Osamu", "" ], [ "Moroi", "Takeo", "" ], [ "Nagata", "Natsumi", "" ], [ "Otono", "Hidetoshi", "" ] ]
A variety of new-physics models predict metastable particles whose decay length is $\lesssim 1$ mm. Conventional displaced-vertex searches are less sensitive to this sub-millimeter decay range, and thus such metastable particles have been looked for only in usual prompt decay searches. In this paper, we show that an additional event-selection cut based on the vertex reconstruction using charged tracks considerably improves the sensitivity of ordinary searches which rely only on kinematic selection criteria, for particles with a decay length of $\gtrsim 100$ $\mu \text{m}$. To that end, we consider a metastable gluino as an example, and study the impact of this new event-selection cut on gluino searches at the LHC by simulating both the signal and Standard Model background processes. Uncertainty of the displaced-vertex reconstruction due to the limited resolution of track reconstruction is taken into account. We also discuss possibilities for optimization of the kinematic selection criteria, which takes advantage of significant reduction of background through the requirement of displaced vertices. In addition, we demonstrate that using the method discussed in this paper it is possible to measure the lifetime of metastable particles with an ${\cal O}(1)$ accuracy at the high-luminosity LHC. Implications for a future 100 TeV collider are also studied, where produced particles tend to be more boosted and thus it is easier to detect the longevity of metastable particles.
hep-ph/0205023
Arnd Brandenburg
A. Brandenburg, Z.G. Si, P. Uwer
QCD-corrected spin analysing power of jets in decays of polarized top quarks
11 pages
Phys.Lett. B539 (2002) 235-241
10.1016/S0370-2693(02)02098-1
PITHA 02/07, DESY 02-055, TTP02-04
hep-ph
null
We present results for the differential distributions of jets from non-leptonic decays of polarized top quarks within the Standard Model, including QCD radiative corrections. Our work extends existing results which are only available for semileptonic top quark decays at the parton level. For $t(\uparrow)$ -> b-jet + 2 light jets we compute in particular the QCD-corrected top-spin analysing power of the b-quark jet and the least energetic light jet. The dependence of the results on the choice of the jet recombination scheme is found to be small. In addition we compute the spin analysing power of the thrust axis. Our results constitute a so far missing ingredient to analyse top quark production and subsequent non-leptonic decay at next-to-leading order in alpha_s, keeping the full information on the top quark polarization.
[ { "created": "Thu, 2 May 2002 15:55:30 GMT", "version": "v1" } ]
2015-06-25
[ [ "Brandenburg", "A.", "" ], [ "Si", "Z. G.", "" ], [ "Uwer", "P.", "" ] ]
We present results for the differential distributions of jets from non-leptonic decays of polarized top quarks within the Standard Model, including QCD radiative corrections. Our work extends existing results which are only available for semileptonic top quark decays at the parton level. For $t(\uparrow)$ -> b-jet + 2 light jets we compute in particular the QCD-corrected top-spin analysing power of the b-quark jet and the least energetic light jet. The dependence of the results on the choice of the jet recombination scheme is found to be small. In addition we compute the spin analysing power of the thrust axis. Our results constitute a so far missing ingredient to analyse top quark production and subsequent non-leptonic decay at next-to-leading order in alpha_s, keeping the full information on the top quark polarization.
0911.1156
Bo-Qiang Ma
Yan Chen, Bo-Qiang Ma
Light flavor baryon spectrum with higher order hyperfine interactions
31 latex pages, final version in journal publication
Nucl.Phys.A831:1-21,2009
10.1016/j.nuclphysa.2009.09.005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the spectrum of light flavor baryons in a quark-model framework by taking into account the order $\mathrm{O}(\alpha_s^2)$ hyperfine interactions due to two-gluon exchange between quarks. The calculated spectrum agree better with the experimental data than the results from hyperfine interactions with only one-gluon exchange. It is also shown that two-gluon exchange hyperfine interactions bring a significantly improved correction to the Gell-Mann--Okubo mass formula. Two-gluon exchange corrections on baryon excitations (including negative parity baryons) are also briefly discussed.
[ { "created": "Fri, 6 Nov 2009 00:52:01 GMT", "version": "v1" } ]
2010-03-11
[ [ "Chen", "Yan", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We study the spectrum of light flavor baryons in a quark-model framework by taking into account the order $\mathrm{O}(\alpha_s^2)$ hyperfine interactions due to two-gluon exchange between quarks. The calculated spectrum agree better with the experimental data than the results from hyperfine interactions with only one-gluon exchange. It is also shown that two-gluon exchange hyperfine interactions bring a significantly improved correction to the Gell-Mann--Okubo mass formula. Two-gluon exchange corrections on baryon excitations (including negative parity baryons) are also briefly discussed.
1710.00272
Wei Tang
Wei Tang
Search for Massive Bosons Decaying to Wg and Zg Using the ATLAS Detector
Talk presented at the APS Division of Particles and Fields Meeting (DPF 2017), July 31-August 4, 2017, Fermilab. C170731. 12 pages, 15 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Standard Model is by far the most encompassing physics theory. With the recent discovery of the Higgs Boson, the Standard Model has performed extremely well against experimental data. However, the theory is intrinsically not complete, it does not address physical phenomenon such as gravity and dark matter. Many proposals for physics beyond the Standard Model predict new massive bosons from additional gauge fields or extended Higgs sectors. This paper examines a preliminary search of possible V gamma decay channels of proposed new bosons.
[ { "created": "Sun, 1 Oct 2017 00:02:49 GMT", "version": "v1" } ]
2017-10-03
[ [ "Tang", "Wei", "" ] ]
The Standard Model is by far the most encompassing physics theory. With the recent discovery of the Higgs Boson, the Standard Model has performed extremely well against experimental data. However, the theory is intrinsically not complete, it does not address physical phenomenon such as gravity and dark matter. Many proposals for physics beyond the Standard Model predict new massive bosons from additional gauge fields or extended Higgs sectors. This paper examines a preliminary search of possible V gamma decay channels of proposed new bosons.
hep-ph/0703291
Pavel Bolokhov
Pavel A. Bolokhov, Maxim Pospelov
Classification of Dimension 5 Lorentz Violating Interactions in the Standard Model
26 pages
Phys.Rev.D77:025022,2008
10.1103/PhysRevD.77.025022
UVIC-TH-06-13
hep-ph hep-th
null
We give a complete classification of mass dimension five Lorentz-non-invariant interactions composed from the Standard Model fields, using the effective field theory approach. We identify different classes of Lorentz violating operators, some of which are protected against transmutation to lower dimensions even at the loop level. Within each class of operators we determine a typical experimental sensitivity to the size of Lorentz violation.
[ { "created": "Tue, 27 Mar 2007 21:22:50 GMT", "version": "v1" }, { "created": "Mon, 26 Nov 2007 04:01:52 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bolokhov", "Pavel A.", "" ], [ "Pospelov", "Maxim", "" ] ]
We give a complete classification of mass dimension five Lorentz-non-invariant interactions composed from the Standard Model fields, using the effective field theory approach. We identify different classes of Lorentz violating operators, some of which are protected against transmutation to lower dimensions even at the loop level. Within each class of operators we determine a typical experimental sensitivity to the size of Lorentz violation.
0806.4890
Graeme Watt
G. Watt, A. D. Martin, W. J. Stirling, R. S. Thorne
Recent Progress in Global PDF Analysis
4 pages, 2 figures. To appear in the proceedings of the 16th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2008), London, England, 7-11 April 2008
null
null
IPPP/08/47, DCPT/08/94
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss selected topics in the forthcoming MSTW 2008 determination of parton distributions by global analysis. The tolerance parameter controlling the uncertainties on the parton distributions is now determined by a new dynamic procedure for each eigenvector of the covariance matrix. New data sets fitted include Tevatron Run II data on inclusive jet production, the lepton charge asymmetry from W decays and the Z rapidity distribution. Predictions are given for the total W and Z cross sections at the Tevatron and LHC.
[ { "created": "Mon, 30 Jun 2008 16:10:15 GMT", "version": "v1" } ]
2008-07-01
[ [ "Watt", "G.", "" ], [ "Martin", "A. D.", "" ], [ "Stirling", "W. J.", "" ], [ "Thorne", "R. S.", "" ] ]
We discuss selected topics in the forthcoming MSTW 2008 determination of parton distributions by global analysis. The tolerance parameter controlling the uncertainties on the parton distributions is now determined by a new dynamic procedure for each eigenvector of the covariance matrix. New data sets fitted include Tevatron Run II data on inclusive jet production, the lepton charge asymmetry from W decays and the Z rapidity distribution. Predictions are given for the total W and Z cross sections at the Tevatron and LHC.
1110.6762
Akin Wingerter
Akin Wingerter and Krishna Mohan Parattu
A Scan for Models of Neutrino Mixing from Non-Abelian Discrete Symmetries
Contribution to the proceedings of "The 2011 Europhysics Conference on High Energy Physics-HEP 2011", July 21-27, 2011, Grenoble, France
null
null
LPSC-11234
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The structure of the neutrino mixing matrix is indicative of an underlying family symmetry that interrelates the three generations of fermions in the Standard Model. We systematically scan the parameter space of 76 discrete non-Abelian family symmetries and construct all models with the Standard Model particle content and up to three flavon fields where we include non-renormalizable interactions of mass dimension five and six. We find that of the 76 groups that we considered, 44 groups can accommodate models that are consistent with experiment at 3sigma, and 38 groups can have models that are tribimaximal. One immediate consequence is that A4 is not "special", but should be considered on equal footing with other groups such as T7 that is the smallest group for which we find tribimaximal mixing, and T13 that has the largest fraction of TBM models. We present the details of a model with theta12=33.9, theta23=49.1, theta13=5.1 to show that a non-zero theta13 can easily be accommodated.
[ { "created": "Mon, 31 Oct 2011 12:14:27 GMT", "version": "v1" } ]
2011-11-01
[ [ "Wingerter", "Akin", "" ], [ "Parattu", "Krishna Mohan", "" ] ]
The structure of the neutrino mixing matrix is indicative of an underlying family symmetry that interrelates the three generations of fermions in the Standard Model. We systematically scan the parameter space of 76 discrete non-Abelian family symmetries and construct all models with the Standard Model particle content and up to three flavon fields where we include non-renormalizable interactions of mass dimension five and six. We find that of the 76 groups that we considered, 44 groups can accommodate models that are consistent with experiment at 3sigma, and 38 groups can have models that are tribimaximal. One immediate consequence is that A4 is not "special", but should be considered on equal footing with other groups such as T7 that is the smallest group for which we find tribimaximal mixing, and T13 that has the largest fraction of TBM models. We present the details of a model with theta12=33.9, theta23=49.1, theta13=5.1 to show that a non-zero theta13 can easily be accommodated.
1903.10506
Ivo de Medeiros Varzielas
Ivo de Medeiros Varzielas, Miguel Levy, Ye-Ling Zhou
Effective alignments and the landscape of $S_4$ flavour models
18 pages, 5 figures, 6 tables
Phys. Rev. D 100, 035027 (2019)
10.1103/PhysRevD.100.035027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the concept of effective alignments: contractions of multiple flavour symmetry breaking flavon fields. These contractions give rise to directions that are hard or impossible to obtain directly by breaking the flavour symmetry. Within this context, and using $S_4$ as the flavour symmetry to exemplify, we perform a phenomenological check of lepton flavour models built from pairing any two effective alignments up to order 2 (in flavon contractions). The check is performed for each pair of effective alignments in a framework with models of constrained sequential dominance type, in a basis where the charged leptons are diagonal. We thus obtain an indication of which effective alignments are interesting for model building, within this so-called $S_4$ landscape. We find three types of viable topologies and provide examples of models realizing this strategy for each topology.
[ { "created": "Mon, 25 Mar 2019 18:00:00 GMT", "version": "v1" } ]
2019-09-04
[ [ "Varzielas", "Ivo de Medeiros", "" ], [ "Levy", "Miguel", "" ], [ "Zhou", "Ye-Ling", "" ] ]
We explore the concept of effective alignments: contractions of multiple flavour symmetry breaking flavon fields. These contractions give rise to directions that are hard or impossible to obtain directly by breaking the flavour symmetry. Within this context, and using $S_4$ as the flavour symmetry to exemplify, we perform a phenomenological check of lepton flavour models built from pairing any two effective alignments up to order 2 (in flavon contractions). The check is performed for each pair of effective alignments in a framework with models of constrained sequential dominance type, in a basis where the charged leptons are diagonal. We thus obtain an indication of which effective alignments are interesting for model building, within this so-called $S_4$ landscape. We find three types of viable topologies and provide examples of models realizing this strategy for each topology.
1203.6618
John M. Cornwall
John M. Cornwall
Entropy in quantum chromodynamics
22 pages, 2 figures. Preprint version of invited review for Modern Physics Letters A
Modern Physics Letters A {\bf 27}, 1230011 (2012)
10.1142/S021773231230011X
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the role of zero-temperature entropy in several closely-related contexts in QCD. The first is entropy associated with disordered condensates, including $< G_{\mu\nu}^2>$. The second is vacuum entropy arising from QCD solitons such as center vortices, yielding confinement and chiral symmetry breaking. The third is entanglement entropy, which is entropy associated with a pure state, such as the QCD vacuum, when the state is partially unobserved and unknown. Typically, entanglement entropy of an unobserved three-volume scales not with the volume but with the area of its bounding surface. The fourth manifestation of entropy in QCD is the configurational entropy of light-particle world-lines and flux tubes; we argue that this entropy is critical for understanding how confinement produces chiral symmetry breakdown, as manifested by a dynamically-massive quark, a massless pion, and a $< \bar{q}q>$ condensate.
[ { "created": "Thu, 29 Mar 2012 18:21:54 GMT", "version": "v1" } ]
2012-03-30
[ [ "Cornwall", "John M.", "" ] ]
We review the role of zero-temperature entropy in several closely-related contexts in QCD. The first is entropy associated with disordered condensates, including $< G_{\mu\nu}^2>$. The second is vacuum entropy arising from QCD solitons such as center vortices, yielding confinement and chiral symmetry breaking. The third is entanglement entropy, which is entropy associated with a pure state, such as the QCD vacuum, when the state is partially unobserved and unknown. Typically, entanglement entropy of an unobserved three-volume scales not with the volume but with the area of its bounding surface. The fourth manifestation of entropy in QCD is the configurational entropy of light-particle world-lines and flux tubes; we argue that this entropy is critical for understanding how confinement produces chiral symmetry breakdown, as manifested by a dynamically-massive quark, a massless pion, and a $< \bar{q}q>$ condensate.
0905.3749
Jeremy Mardon
Jeremy Mardon, Yasunori Nomura, Jesse Thaler
Cosmic Signals from the Hidden Sector
40 pages, 7 figures; references and comments added
Phys.Rev.D80:035013,2009
10.1103/PhysRevD.80.035013
UCB-PTH-09/18
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmologically long-lived, composite states arise as natural dark matter candidates in theories with a strongly interacting hidden sector at a scale of 10 - 100 TeV. Light axion-like states, with masses in the 1 MeV - 10 GeV range, are also generic, and can decay via Higgs couplings to light standard model particles. Such a scenario is well motivated in the context of very low energy supersymmetry breaking, where ubiquitous cosmological problems associated with the gravitino are avoided. We investigate the astrophysical and collider signatures of this scenario, assuming that dark matter decays into the axion-like states via dimension six operators, and we present an illustrative model exhibiting these features. We conclude that the recent data from PAMELA, FERMI, and H.E.S.S. points to this setup as a compelling paradigm for dark matter. This has important implications for future diffuse gamma ray measurements and collider searches.
[ { "created": "Sat, 23 May 2009 22:17:43 GMT", "version": "v1" }, { "created": "Wed, 3 Jun 2009 23:42:01 GMT", "version": "v2" } ]
2010-05-28
[ [ "Mardon", "Jeremy", "" ], [ "Nomura", "Yasunori", "" ], [ "Thaler", "Jesse", "" ] ]
Cosmologically long-lived, composite states arise as natural dark matter candidates in theories with a strongly interacting hidden sector at a scale of 10 - 100 TeV. Light axion-like states, with masses in the 1 MeV - 10 GeV range, are also generic, and can decay via Higgs couplings to light standard model particles. Such a scenario is well motivated in the context of very low energy supersymmetry breaking, where ubiquitous cosmological problems associated with the gravitino are avoided. We investigate the astrophysical and collider signatures of this scenario, assuming that dark matter decays into the axion-like states via dimension six operators, and we present an illustrative model exhibiting these features. We conclude that the recent data from PAMELA, FERMI, and H.E.S.S. points to this setup as a compelling paradigm for dark matter. This has important implications for future diffuse gamma ray measurements and collider searches.
1508.05392
David McKeen
Akshay Ghalsasi, David McKeen, Ann E. Nelson
Baryogenesis via Mesino Oscillations
14 pages, 6 figures
Phys. Rev. D 92, 076014 (2015)
10.1103/PhysRevD.92.076014
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new mechanism for baryogenesis at the 1-200 MeV scale. Enhancement of CP violation takes place via interference between oscillations and decays of mesinos--bound states of a scalar quark and antiquark and their CP conjugates. We present the mechanism in a simplified model with four new fundamental particles, with masses between 300 GeV and 10 TeV, and show that some of the experimentally allowed parameter space can give the observed baryon-to-entropy ratio.
[ { "created": "Fri, 21 Aug 2015 20:06:02 GMT", "version": "v1" } ]
2015-11-04
[ [ "Ghalsasi", "Akshay", "" ], [ "McKeen", "David", "" ], [ "Nelson", "Ann E.", "" ] ]
We propose a new mechanism for baryogenesis at the 1-200 MeV scale. Enhancement of CP violation takes place via interference between oscillations and decays of mesinos--bound states of a scalar quark and antiquark and their CP conjugates. We present the mechanism in a simplified model with four new fundamental particles, with masses between 300 GeV and 10 TeV, and show that some of the experimentally allowed parameter space can give the observed baryon-to-entropy ratio.
hep-ph/9302284
null
O.J.P. Eboli, M.C. Gonzalez-Garcia, F. Halzen and D. Zeppenfeld
Measuring the Gamma-Gamma Coupling of the Higgs at Linear Colliders
(Latex file, 5 pages, 3 figures avalaible upon request) MAD/PH/743
Phys.Rev. D48 (1993) 1430-1432
10.1103/PhysRevD.48.1430
null
hep-ph
null
Observing the production of the Higgs particle in the $\gamma$-$\gamma$ mode of a linear $e^+e^-$ collider allows for the measurement of the $H\gamma\gamma$ coupling. We point out that for the intermediate Higgs mass range this measurement is considerably more challenging than previously believed. The $b \bar b$ signature receives a large background from the production of heavy quark pairs by resolved photons. We quantify the experimental requirements needed to make a meaningful measurement in the presence of this background.
[ { "created": "Sat, 20 Feb 1993 20:59:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Eboli", "O. J. P.", "" ], [ "Gonzalez-Garcia", "M. C.", "" ], [ "Halzen", "F.", "" ], [ "Zeppenfeld", "D.", "" ] ]
Observing the production of the Higgs particle in the $\gamma$-$\gamma$ mode of a linear $e^+e^-$ collider allows for the measurement of the $H\gamma\gamma$ coupling. We point out that for the intermediate Higgs mass range this measurement is considerably more challenging than previously believed. The $b \bar b$ signature receives a large background from the production of heavy quark pairs by resolved photons. We quantify the experimental requirements needed to make a meaningful measurement in the presence of this background.
0802.1061
Carlos Luis Schat
Ezequiel Alvarez, Leandro Da Rold, Carlos Schat, Alejandro Szynkman
Electroweak precision constraints on the Lee-Wick Standard Model
24 pages, 7 figures
JHEP0804:026,2008
10.1088/1126-6708/2008/04/026
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform an analysis of the electroweak precision observables in the Lee-Wick Standard Model. The most stringent restrictions come from the S and T parameters that receive important tree level and one loop contributions. In general the model predicts a large positive S and a negative T. To reproduce the electroweak data, if all the Lee-Wick masses are of the same order, the Lee-Wick scale is of order 5 TeV. We show that it is possible to find some regions in the parameter space with a fermionic state as light as 2.4-3.5 TeV, at the price of rising all the other masses to be larger than 5-8 TeV. To obtain a light Higgs with such heavy resonances a fine-tuning of order a few per cent, at least, is needed. We also propose a simple extension of the model including a fourth generation of Standard Model fermions with their Lee-Wick partners. We show that in this case it is possible to pass the electroweak constraints with Lee-Wick fermionic masses of order 0.4-1.5 TeV and Lee-Wick gauge masses of order 3 TeV.
[ { "created": "Thu, 7 Feb 2008 20:38:51 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alvarez", "Ezequiel", "" ], [ "Da Rold", "Leandro", "" ], [ "Schat", "Carlos", "" ], [ "Szynkman", "Alejandro", "" ] ]
We perform an analysis of the electroweak precision observables in the Lee-Wick Standard Model. The most stringent restrictions come from the S and T parameters that receive important tree level and one loop contributions. In general the model predicts a large positive S and a negative T. To reproduce the electroweak data, if all the Lee-Wick masses are of the same order, the Lee-Wick scale is of order 5 TeV. We show that it is possible to find some regions in the parameter space with a fermionic state as light as 2.4-3.5 TeV, at the price of rising all the other masses to be larger than 5-8 TeV. To obtain a light Higgs with such heavy resonances a fine-tuning of order a few per cent, at least, is needed. We also propose a simple extension of the model including a fourth generation of Standard Model fermions with their Lee-Wick partners. We show that in this case it is possible to pass the electroweak constraints with Lee-Wick fermionic masses of order 0.4-1.5 TeV and Lee-Wick gauge masses of order 3 TeV.
hep-ph/0307060
Ulrich Jentschura
Ulrich D. Jentschura, Christoph H. Keitel and Krzysztof Pachucki
Two-Loop QED Bound-State Calculations and Squared Decay Rates
12 pages, 2 figures, LaTeX
Can.J.Phys. 80 (2002) 1213-1223
10.1139/p02-081
null
hep-ph
null
We discuss the epsilon-method as used in various recent QED bound-state calculations by considering mathematical model examples. Recently obtained results for higher-order self-energy binding corrections at the two-loop level are reviewed. Problems associated with the interpretation of squared decay rates as radiative bound-state energy level shifts are discussed. We briefly expand on the relation of squared decay rates to nonresonant and radiative corrections to the Lorentzian line shape, including their dependence on the experimental process under study.
[ { "created": "Fri, 4 Jul 2003 11:29:09 GMT", "version": "v1" } ]
2009-11-10
[ [ "Jentschura", "Ulrich D.", "" ], [ "Keitel", "Christoph H.", "" ], [ "Pachucki", "Krzysztof", "" ] ]
We discuss the epsilon-method as used in various recent QED bound-state calculations by considering mathematical model examples. Recently obtained results for higher-order self-energy binding corrections at the two-loop level are reviewed. Problems associated with the interpretation of squared decay rates as radiative bound-state energy level shifts are discussed. We briefly expand on the relation of squared decay rates to nonresonant and radiative corrections to the Lorentzian line shape, including their dependence on the experimental process under study.
1905.09457
Ruibo Li
Ruibo Li, Bo-Wen Wang, Kai Wang, Xiaoyuan Zhang, and Zhenyu Zhou
Probe Charm Yukawa at the future $e^{-}p$ and $e^{+}e^{-}$ colliders
28 pages, 9 figures and 11 tables
Phys. Rev. D 100, 053008 (2019)
10.1103/PhysRevD.100.053008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Large Hadron Collider (LHC) has provided direct evidence of Yukawa couplings between the third generation charged fermions and the 125 GeV Higgs boson. Whether the first two generation charged fermions arise from exactly the same mechanism becomes the next interesting question. Therefore, direct measurements of charm or muon Yukawa couplings will be crucial to answering this puzzle. The charm Yukawa measurement at the LHC suffers from severe QCD background and it is extremely difficult to reach the sensitivity. In this paper, we compare the potential of probing charm Yukawa coupling at the two proposed future "Higgs Factory" experiments, the Large Hadron electron Collider (LHeC) and Circular electron positron collider (CEPC). At the LHeC, Higgs bosons will be produced via weak boson fusion and the energetic forward jet may suppress the background significantly. However, due to huge $\gamma-g$ scattering background, the potential of LHeC search is still limited. With $-80\%$ polarized electron beam of 60 GeV, the signal significance can only reach $2\sigma$ for $ \kappa_{c}\simeq 1$ with a 3 ab$^{-1}$ integrated luminosity. In comparison, measurement at the CEPC can then reach $8.0\sigma$ for $\kappa_{c}\simeq 1$ with a 2 ab$^{-1}$ of data.
[ { "created": "Thu, 23 May 2019 04:30:45 GMT", "version": "v1" }, { "created": "Wed, 9 Oct 2019 03:48:56 GMT", "version": "v2" } ]
2019-10-16
[ [ "Li", "Ruibo", "" ], [ "Wang", "Bo-Wen", "" ], [ "Wang", "Kai", "" ], [ "Zhang", "Xiaoyuan", "" ], [ "Zhou", "Zhenyu", "" ] ]
Large Hadron Collider (LHC) has provided direct evidence of Yukawa couplings between the third generation charged fermions and the 125 GeV Higgs boson. Whether the first two generation charged fermions arise from exactly the same mechanism becomes the next interesting question. Therefore, direct measurements of charm or muon Yukawa couplings will be crucial to answering this puzzle. The charm Yukawa measurement at the LHC suffers from severe QCD background and it is extremely difficult to reach the sensitivity. In this paper, we compare the potential of probing charm Yukawa coupling at the two proposed future "Higgs Factory" experiments, the Large Hadron electron Collider (LHeC) and Circular electron positron collider (CEPC). At the LHeC, Higgs bosons will be produced via weak boson fusion and the energetic forward jet may suppress the background significantly. However, due to huge $\gamma-g$ scattering background, the potential of LHeC search is still limited. With $-80\%$ polarized electron beam of 60 GeV, the signal significance can only reach $2\sigma$ for $ \kappa_{c}\simeq 1$ with a 3 ab$^{-1}$ integrated luminosity. In comparison, measurement at the CEPC can then reach $8.0\sigma$ for $\kappa_{c}\simeq 1$ with a 2 ab$^{-1}$ of data.
0910.1529
Richard F. Lebed
Christopher D. Carone, Richard F. Lebed
Optimal Parametrization of Deviations from Tribimaximal Form of the Neutrino Mass Matrix
9 pages, no figures, ReVTeX. Improved treatment of Majorana phases, added references
Phys.Rev.D80:117301,2009
10.1103/PhysRevD.80.117301
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a general parametrization for the neutrino Majorana mass matrix in which all possible deviations from tribimaximal mixing are given by three complex parameters, and the deviation from each tribimaximal mixing eigenvector is identified with precisely two of them. This parametrization provides a useful tool for classifying the corrections to exact tribimaximal mixing in flavor models.
[ { "created": "Thu, 8 Oct 2009 15:19:56 GMT", "version": "v1" }, { "created": "Wed, 28 Oct 2009 19:45:16 GMT", "version": "v2" } ]
2010-01-08
[ [ "Carone", "Christopher D.", "" ], [ "Lebed", "Richard F.", "" ] ]
We obtain a general parametrization for the neutrino Majorana mass matrix in which all possible deviations from tribimaximal mixing are given by three complex parameters, and the deviation from each tribimaximal mixing eigenvector is identified with precisely two of them. This parametrization provides a useful tool for classifying the corrections to exact tribimaximal mixing in flavor models.
1406.2927
Reza Moazzemi
Zohreh Bagherian, Mohammad Mahdi Ettefaghi, Zina Haghgouyan, Reza Moazzemi
A new parameter space study of the singlet fermionic cold dark matter model
12 pages, 7 figures, revtex4 format, revised version, some references added, to appear in JCAP
JCAP 10 (2014) 033
10.1088/1475-7516/2014/10/033
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the standard model (SM) extended by a gauge singlet fermion as cold dark matter (SFCDM) and a gauge singlet scalar (singlet Higgs) as a mediator. The parameter space of the SM is enlarged by seven new ones. We obtain the total annihilation cross section of singlet fermions to the SM particles and singlet Higgs at tree level. Regarding the relic abundance constraint obtained by WMAP observations, we study the dependency on each parameter separately, for dark matter masses up to 1 TeV. In particular, the coupling of SFCDM to singlet Higgs $g_s$, the SFCDM mass $m_\psi$, the second Higgs mass $m_{h_2}$, and the Higgs bosons mixing angel $\theta$ are investigated accurately. Three other parameters play no significant role. For a maximal mixing of Higgs bosons or at resonances, $g_s$ is applicable for the perturbation theory at tree level. We also obtain the scattering cross section of SFCDM off nucleons and compare our results with experiments which have already reported data in this mass range; XENON100, LUX, COUPP and PICASSO collaborations. Our results show that the SFCDM is excluded by these experiments for choosing parameters which are consistent with perturbation theory and relic abundance constraints.
[ { "created": "Tue, 10 Jun 2014 11:02:29 GMT", "version": "v1" }, { "created": "Sun, 15 Jun 2014 12:45:32 GMT", "version": "v2" }, { "created": "Fri, 10 Oct 2014 15:35:41 GMT", "version": "v3" } ]
2015-06-19
[ [ "Bagherian", "Zohreh", "" ], [ "Ettefaghi", "Mohammad Mahdi", "" ], [ "Haghgouyan", "Zina", "" ], [ "Moazzemi", "Reza", "" ] ]
We consider the standard model (SM) extended by a gauge singlet fermion as cold dark matter (SFCDM) and a gauge singlet scalar (singlet Higgs) as a mediator. The parameter space of the SM is enlarged by seven new ones. We obtain the total annihilation cross section of singlet fermions to the SM particles and singlet Higgs at tree level. Regarding the relic abundance constraint obtained by WMAP observations, we study the dependency on each parameter separately, for dark matter masses up to 1 TeV. In particular, the coupling of SFCDM to singlet Higgs $g_s$, the SFCDM mass $m_\psi$, the second Higgs mass $m_{h_2}$, and the Higgs bosons mixing angel $\theta$ are investigated accurately. Three other parameters play no significant role. For a maximal mixing of Higgs bosons or at resonances, $g_s$ is applicable for the perturbation theory at tree level. We also obtain the scattering cross section of SFCDM off nucleons and compare our results with experiments which have already reported data in this mass range; XENON100, LUX, COUPP and PICASSO collaborations. Our results show that the SFCDM is excluded by these experiments for choosing parameters which are consistent with perturbation theory and relic abundance constraints.
2010.05148
Yao-Bei Liu
Yao-Bei Liu and Stefano Moretti
Probing tqZ anomalous couplings in the trilepton signal at the HL-LHC, HE-LHC and FCC-hh
21 pages, 6 figures, 8 tables, to appear in Chinese Physics C
null
10.1088/1674-1137/abe0c0
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the prospects for discovering the Flavour Changing Neutral Current (FCNC) $tqZ$ couplings via two production processes yielding trilepton signals: top quark pair production $pp\to t\bar{t}$ with one top decaying to the $Z$ boson and one light jet and the anomalous single top plus $Z$ boson production process $pp\to tZ$. We study these channels at various successors of the Large Hadron Collider~(LHC), i.e., the approved High-Luminosity LHC (HL-LHC) as well as the proposed High-Energy LHC~(HE-LHC) and Future Circular Collider in hadron-hadron mode (FCC-hh). We perform a full simulation for the signals and the relevant Standard Model (SM) backgrounds and obtain limits on the Branching Ratios (BRs) of $t\to qZ~(q=u,c)$, eventually yielding a trilepton final state through the decay modes $t\to b W^{+}\to b\ell^{+}\nu_{\ell}$ and $Z\to \ell^{+}\ell^{-}$. The upper limits on these FCNC BRs at 95\% Confidence Level (CL) are obtained at the HL-LHC with $\sqrt s=14$ TeV and 3 ab$^{-1}$, at the HE-LHC with $\sqrt s=27$ TeV and 15 ab$^{-1}$ as well as at the FCC-hh with $\sqrt s=100$ TeV and 30 ab$^{-1}$.
[ { "created": "Sun, 11 Oct 2020 03:25:41 GMT", "version": "v1" }, { "created": "Wed, 6 Jan 2021 08:37:55 GMT", "version": "v2" } ]
2021-05-26
[ [ "Liu", "Yao-Bei", "" ], [ "Moretti", "Stefano", "" ] ]
We investigate the prospects for discovering the Flavour Changing Neutral Current (FCNC) $tqZ$ couplings via two production processes yielding trilepton signals: top quark pair production $pp\to t\bar{t}$ with one top decaying to the $Z$ boson and one light jet and the anomalous single top plus $Z$ boson production process $pp\to tZ$. We study these channels at various successors of the Large Hadron Collider~(LHC), i.e., the approved High-Luminosity LHC (HL-LHC) as well as the proposed High-Energy LHC~(HE-LHC) and Future Circular Collider in hadron-hadron mode (FCC-hh). We perform a full simulation for the signals and the relevant Standard Model (SM) backgrounds and obtain limits on the Branching Ratios (BRs) of $t\to qZ~(q=u,c)$, eventually yielding a trilepton final state through the decay modes $t\to b W^{+}\to b\ell^{+}\nu_{\ell}$ and $Z\to \ell^{+}\ell^{-}$. The upper limits on these FCNC BRs at 95\% Confidence Level (CL) are obtained at the HL-LHC with $\sqrt s=14$ TeV and 3 ab$^{-1}$, at the HE-LHC with $\sqrt s=27$ TeV and 15 ab$^{-1}$ as well as at the FCC-hh with $\sqrt s=100$ TeV and 30 ab$^{-1}$.
hep-ph/9805423
V. O. Galkin
D. Ebert, R. N. Faustov, V. O. Galkin
Exclusive semileptonic decays of B mesons to orbitally excited D mesons in the relativistic quark model
11 pages, Revtex, 4 figures, uses epsf and rotating.sty
Phys.Lett. B434 (1998) 365-372
10.1016/S0370-2693(98)00758-8
HUB-EP-98/30
hep-ph
null
Exclusive semileptonic B meson decays to orbitally excited D mesons are investigated in the infinitely heavy quark limit in the framework of the relativistic quark model based on the quasipotential approach. The B\to D^{**}e\nu Isgur-Wise functions \tau_{3/2}(w) and \tau_{1/2}(w) are determined. It is found that the relativistic transformation of the meson wave functions (Wigner rotation of the light quark spin) contribute already at the leading order of the heavy quark expansion.
[ { "created": "Fri, 22 May 1998 12:41:36 GMT", "version": "v1" } ]
2009-10-31
[ [ "Ebert", "D.", "" ], [ "Faustov", "R. N.", "" ], [ "Galkin", "V. O.", "" ] ]
Exclusive semileptonic B meson decays to orbitally excited D mesons are investigated in the infinitely heavy quark limit in the framework of the relativistic quark model based on the quasipotential approach. The B\to D^{**}e\nu Isgur-Wise functions \tau_{3/2}(w) and \tau_{1/2}(w) are determined. It is found that the relativistic transformation of the meson wave functions (Wigner rotation of the light quark spin) contribute already at the leading order of the heavy quark expansion.
hep-ph/0111341
Anton Rebhan
A. Rebhan
Hard thermal loops and QCD thermodynamics
26 pages, 3 figures. Lectures given at the NATO Advanced Study Institute ``QCD perspectives on hot and dense matter'', August 6-18, 2001, in Carg\`ese, Corsica, France
null
null
TUW-01-30
hep-ph
null
These lectures give an introduction to thermal perturbation theory, hard thermal loops, and their use in a nonperturbative, approximately self-consistent resummation of the thermodynamical potentials of quantum chromodynamics.
[ { "created": "Tue, 27 Nov 2001 16:55:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rebhan", "A.", "" ] ]
These lectures give an introduction to thermal perturbation theory, hard thermal loops, and their use in a nonperturbative, approximately self-consistent resummation of the thermodynamical potentials of quantum chromodynamics.
1709.04542
Alex Palameta
A. Palameta, J. Ho, D. Harnett, T. G. Steele
Heavy Quarkonium ($1^{--}$) Meson-Hybrid Mixing from QCD Sum Rules
QCD-17 conference proceedings article
null
10.1016/j.nuclphysbps.2018.03.015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use QCD Laplace sum-rules to explore mixing between conventional mesons and hybrids in the heavy quarkonium vector $J^{PC}\!=\!1^{--}$ channel. Our cross-correlator includes perturbation theory and contributions proportional to the four-dimensional and six-dimensional gluon condensates. We input experimentally determined charmonium and bottomonium hadron masses into both single and multi-resonance models in order to test them for conventional meson and hybrid components. In the charmonium sector we find evidence for meson-hybrid mixing in the $J/\psi$ and a $\approx4.3$ GeV resonance. In the bottomonium sector, we find that the $\Upsilon(1S)$, $\Upsilon(2S)$, $\Upsilon(3S)$, and $\Upsilon(4S)$ all exhibit mixing.
[ { "created": "Wed, 13 Sep 2017 21:17:25 GMT", "version": "v1" } ]
2018-09-03
[ [ "Palameta", "A.", "" ], [ "Ho", "J.", "" ], [ "Harnett", "D.", "" ], [ "Steele", "T. G.", "" ] ]
We use QCD Laplace sum-rules to explore mixing between conventional mesons and hybrids in the heavy quarkonium vector $J^{PC}\!=\!1^{--}$ channel. Our cross-correlator includes perturbation theory and contributions proportional to the four-dimensional and six-dimensional gluon condensates. We input experimentally determined charmonium and bottomonium hadron masses into both single and multi-resonance models in order to test them for conventional meson and hybrid components. In the charmonium sector we find evidence for meson-hybrid mixing in the $J/\psi$ and a $\approx4.3$ GeV resonance. In the bottomonium sector, we find that the $\Upsilon(1S)$, $\Upsilon(2S)$, $\Upsilon(3S)$, and $\Upsilon(4S)$ all exhibit mixing.
hep-ph/0012208
Yadong Yang
Mao-Zhi Yang (Hiroshima U. & IHEP, CAS), Ya-Dong Yang (Ochanomizu U. & TECHNION)
Revisiting Charmless Two-Body B Decays involving $\eta^{\prime}$ and $\eta$
34 pages, 5 figures. Title changed, text polished and some statements softened
Nucl.Phys. B609 (2001) 469
10.1016/S0550-3213(01)00313-3
OCHA-PP-166, HUPD-011
hep-ph
null
We have studied charmless two-body B decays involving $\eta$ and $\eta'$ in the framework of QCD improved factorization appraoch. The spectator hard scattering mechanism for $\eta'$ production have been re-examined and extended, which contributions are incorporated consistently into the factorizable leading contributions. It is found that the conventional mechanism would give $Br(B\to \eta' K)\sim 30\times 10^{-6}$ which agrees with predictions based on naive factorization approaches. With the incorporation of spectator hard scattering mechanism contributions, theoretical predictions are improved much and the bulk of $Br(B\to \eta' K)$ are accommodated in the reasonable parameter space. We have also presented calculations of $g^{\ast}g^{\ast}-\eta^{(\prime)}$ transition form factors within the standard hard scattering approach. It is shown that the new contributions in the modes such as $B\to \eta' +vector$ and $B\to \eta+ \pi, \rho, K^{(\ast)}$ are small. Direct CP-violation in those decay modes are predicted. It is shown that the prospects for measuring direct CP-violation effects in $B^{\pm} \to$ $\eta' K^{\pm}$, $\eta' \pi^{\pm}$, $\eta \pi^{\pm}$, and $\eta K^{\pm}$ are promising at B factories in the near future.
[ { "created": "Sun, 17 Dec 2000 18:30:28 GMT", "version": "v1" }, { "created": "Wed, 10 Jan 2001 17:54:26 GMT", "version": "v2" }, { "created": "Sun, 13 May 2001 15:22:27 GMT", "version": "v3" } ]
2009-10-31
[ [ "Yang", "Mao-Zhi", "", "Hiroshima U. & IHEP, CAS" ], [ "Yang", "Ya-Dong", "", "Ochanomizu U. &\n TECHNION" ] ]
We have studied charmless two-body B decays involving $\eta$ and $\eta'$ in the framework of QCD improved factorization appraoch. The spectator hard scattering mechanism for $\eta'$ production have been re-examined and extended, which contributions are incorporated consistently into the factorizable leading contributions. It is found that the conventional mechanism would give $Br(B\to \eta' K)\sim 30\times 10^{-6}$ which agrees with predictions based on naive factorization approaches. With the incorporation of spectator hard scattering mechanism contributions, theoretical predictions are improved much and the bulk of $Br(B\to \eta' K)$ are accommodated in the reasonable parameter space. We have also presented calculations of $g^{\ast}g^{\ast}-\eta^{(\prime)}$ transition form factors within the standard hard scattering approach. It is shown that the new contributions in the modes such as $B\to \eta' +vector$ and $B\to \eta+ \pi, \rho, K^{(\ast)}$ are small. Direct CP-violation in those decay modes are predicted. It is shown that the prospects for measuring direct CP-violation effects in $B^{\pm} \to$ $\eta' K^{\pm}$, $\eta' \pi^{\pm}$, $\eta \pi^{\pm}$, and $\eta K^{\pm}$ are promising at B factories in the near future.
1901.09076
Anna Stasto
Nestor Armesto, Paul R. Newman, Wojciech Slominski, Anna M. Stasto
Inclusive diffraction in future electron-proton and electron-ion colliders
24 pages, 16 figures
Phys. Rev. D 100, 074022 (2019)
10.1103/PhysRevD.100.074022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse the possibilities for the study of inclusive diffraction offered by future electron--proton/nucleus colliders in the TeV regime, the Large Hadron-electron Collider as an upgrade of the HL-LHC and the Future Circular Collider in electron-hadron mode. Compared to $ep$ collisions at HERA, we find an extension of the available kinematic range in $x$ by a factor of order $20$ and of the maximum $Q^2$ by a factor of order $100$ for LHeC, while the FCC version would extend the coverage by a further order of magnitude both in $x$ and $Q^2$. This translates into a range of available momentum fraction of the diffractive exchange with respect to the hadron ($\xi$), down to $10^{-4}-10^{-5}$ for a wide range of the momentum fraction of the parton with respect to the diffractive exchange ($\beta$). Using the same framework and methodology employed in previous studies at HERA, considering only the experimental uncertainties and not those stemming from the functional form of the initial conditions or other ones of theoretical origin, and under very conservative assumptions for the luminosities and systematic errors, we find an improvement in the extraction of diffractive parton densities from fits to reduced cross sections for inclusive coherent diffraction in $ep$ by about an order of magnitude. For $eA$, we also perform the simulations for the Electron Ion Collider. We find that an extraction of the currently unmeasured nuclear diffractive parton densities is possible with similar accuracy to that in $ep$.
[ { "created": "Fri, 25 Jan 2019 20:40:11 GMT", "version": "v1" }, { "created": "Mon, 10 Aug 2020 22:14:40 GMT", "version": "v2" } ]
2020-08-12
[ [ "Armesto", "Nestor", "" ], [ "Newman", "Paul R.", "" ], [ "Slominski", "Wojciech", "" ], [ "Stasto", "Anna M.", "" ] ]
We analyse the possibilities for the study of inclusive diffraction offered by future electron--proton/nucleus colliders in the TeV regime, the Large Hadron-electron Collider as an upgrade of the HL-LHC and the Future Circular Collider in electron-hadron mode. Compared to $ep$ collisions at HERA, we find an extension of the available kinematic range in $x$ by a factor of order $20$ and of the maximum $Q^2$ by a factor of order $100$ for LHeC, while the FCC version would extend the coverage by a further order of magnitude both in $x$ and $Q^2$. This translates into a range of available momentum fraction of the diffractive exchange with respect to the hadron ($\xi$), down to $10^{-4}-10^{-5}$ for a wide range of the momentum fraction of the parton with respect to the diffractive exchange ($\beta$). Using the same framework and methodology employed in previous studies at HERA, considering only the experimental uncertainties and not those stemming from the functional form of the initial conditions or other ones of theoretical origin, and under very conservative assumptions for the luminosities and systematic errors, we find an improvement in the extraction of diffractive parton densities from fits to reduced cross sections for inclusive coherent diffraction in $ep$ by about an order of magnitude. For $eA$, we also perform the simulations for the Electron Ion Collider. We find that an extraction of the currently unmeasured nuclear diffractive parton densities is possible with similar accuracy to that in $ep$.
1804.01043
Giulia Pancheri Dr.
Giulia Pancheri and Yogendra. N. Srivastava
A Democratic Resummation Procedure of Soft Gluon Emission for Hadronic Inelastic Cross-sections and Survival Probabilities
6 pages, 6 figures, to appear in the Proceedings of LFC17: Old and New Strong Interactions from LHC to Future Colliders, ECT*, Trento, 11-15 September 2017
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a model for soft gluon re-summation based on a statistical description of independent emissions during inelastic collisions. The model is applied to estimate Survival Probabilities at the LHC. A comparison with other models and experimental data is presented.
[ { "created": "Tue, 3 Apr 2018 15:43:43 GMT", "version": "v1" } ]
2018-04-04
[ [ "Pancheri", "Giulia", "" ], [ "Srivastava", "Yogendra. N.", "" ] ]
We discuss a model for soft gluon re-summation based on a statistical description of independent emissions during inelastic collisions. The model is applied to estimate Survival Probabilities at the LHC. A comparison with other models and experimental data is presented.
1003.3033
Stephen Godfrey
Stephen Godfrey (Carleton U. and TRIUMF) and Ken Moats (Carleton U)
Exploring Higgs Triplet Models via Vector Boson Scattering at the LHC
14 pages, 11 figures, references added
Phys.Rev.D81:075026,2010
10.1103/PhysRevD.81.075026
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the results of a study of Higgs triplet boson production arising in the Littlest Higgs, Left-Right Symmetric, and Georgi-Machacek models in the W^\pm W^\pm, W^\pm Z, W^+ W^-, and Z Z channels at the LHC. We focus on the "gold-plated" purely leptonic decay modes and consider the irreducible electroweak, QCD, and t-quark backgrounds, applying a combination of forward-jet-tagging, central-jet-vetoing, and stringent leptonic cuts to suppress the backgrounds. We find that, given the constraints on the triplet vacuum expectation value (vev), considerable luminosity is required to observe Higgs triplet bosons in vector boson scattering. Observing a Higgs triplet at the LHC is most promising in the Georgi-Machacek model due to a weaker constraint on the triplet vev. In this model, we find that a Higgs triplet boson with a mass of 1.0 (1.5) TeV can be observed at the LHC with an integrated luminosity as low as 41 (119) fb^{-1} in the W^\pm W^\pm channel and as low as 171 (474) fb^{-1} in the W^\pm Z channel. Observation of Higgs triplet bosons in these channels would help identify the underlying theory.
[ { "created": "Mon, 15 Mar 2010 21:01:22 GMT", "version": "v1" }, { "created": "Tue, 23 Mar 2010 00:26:47 GMT", "version": "v2" }, { "created": "Tue, 13 Apr 2010 23:57:54 GMT", "version": "v3" } ]
2015-03-13
[ [ "Godfrey", "Stephen", "", "Carleton U. and TRIUMF" ], [ "Moats", "Ken", "", "Carleton U" ] ]
We present the results of a study of Higgs triplet boson production arising in the Littlest Higgs, Left-Right Symmetric, and Georgi-Machacek models in the W^\pm W^\pm, W^\pm Z, W^+ W^-, and Z Z channels at the LHC. We focus on the "gold-plated" purely leptonic decay modes and consider the irreducible electroweak, QCD, and t-quark backgrounds, applying a combination of forward-jet-tagging, central-jet-vetoing, and stringent leptonic cuts to suppress the backgrounds. We find that, given the constraints on the triplet vacuum expectation value (vev), considerable luminosity is required to observe Higgs triplet bosons in vector boson scattering. Observing a Higgs triplet at the LHC is most promising in the Georgi-Machacek model due to a weaker constraint on the triplet vev. In this model, we find that a Higgs triplet boson with a mass of 1.0 (1.5) TeV can be observed at the LHC with an integrated luminosity as low as 41 (119) fb^{-1} in the W^\pm W^\pm channel and as low as 171 (474) fb^{-1} in the W^\pm Z channel. Observation of Higgs triplet bosons in these channels would help identify the underlying theory.
hep-ph/0204182
Brigitte Hiller
Alexander A. Osipov and Brigitte Hiller
Path integral bosonization of the 't Hooft determinant: fluctuations and multiple vacua
RevTex, 9 pages, 8 figures, slightly modified introduction, one added reference and added acknowledgements, version accepted in Phys. Lett. B
Phys.Lett. B539 (2002) 76-84
10.1016/S0370-2693(02)02041-5
null
hep-ph
null
The 't Hooft six quark flavor mixing interaction (N_f=3) is bosonized by the path integral method. The considered complete Lagrangian is constructed on the basis of the combined 't Hooft and U(3)X U(3) extended chiral four fermion Nambu-Jona-Lasinio interactions. The method of the steepest descents is used to derive the effective mesonic Lagrangian. Additionally to the known lowest order stationary phase (SP) result of Reinhardt and Alkofer we obtain the contribution from the small quantum fluctuations of bosonic configurations around their stationary phase trajectories. It affects the vacuum state of hadrons at low energies: whereas without the inclusion of quantum fluctuations the vacuum is uniquely defined for a fixed set of the model parameters, fluctuations give rise to multivalued solutions of the gap equations, marked at instances by drastic changes in the quark condensates. We derive the new gap equations and analyse them in comparison with known results. We classify the solutions according to the number of extrema they may accomodate. We find up to four solutions in the 0<m_(u,s)<3$ GeV region.
[ { "created": "Tue, 16 Apr 2002 09:46:14 GMT", "version": "v1" }, { "created": "Mon, 3 Jun 2002 09:36:37 GMT", "version": "v2" } ]
2015-06-25
[ [ "Osipov", "Alexander A.", "" ], [ "Hiller", "Brigitte", "" ] ]
The 't Hooft six quark flavor mixing interaction (N_f=3) is bosonized by the path integral method. The considered complete Lagrangian is constructed on the basis of the combined 't Hooft and U(3)X U(3) extended chiral four fermion Nambu-Jona-Lasinio interactions. The method of the steepest descents is used to derive the effective mesonic Lagrangian. Additionally to the known lowest order stationary phase (SP) result of Reinhardt and Alkofer we obtain the contribution from the small quantum fluctuations of bosonic configurations around their stationary phase trajectories. It affects the vacuum state of hadrons at low energies: whereas without the inclusion of quantum fluctuations the vacuum is uniquely defined for a fixed set of the model parameters, fluctuations give rise to multivalued solutions of the gap equations, marked at instances by drastic changes in the quark condensates. We derive the new gap equations and analyse them in comparison with known results. We classify the solutions according to the number of extrema they may accomodate. We find up to four solutions in the 0<m_(u,s)<3$ GeV region.
hep-ph/0401010
Steven Weinberg
Steven Weinberg
The Making of the Standard Model
21 pages
Eur.Phys.J.C34:5-13,2004
10.1140/epjc/s2004-01761-1
null
hep-ph
null
This is the edited text of a talk given at CERN on Septembr 16, 2003, as part of a celebration of the 30th anniversary of the discovery of neutral currents and the 20th anniversary of the discovery of the W and Z particles.
[ { "created": "Sat, 3 Jan 2004 03:04:20 GMT", "version": "v1" } ]
2009-03-02
[ [ "Weinberg", "Steven", "" ] ]
This is the edited text of a talk given at CERN on Septembr 16, 2003, as part of a celebration of the 30th anniversary of the discovery of neutral currents and the 20th anniversary of the discovery of the W and Z particles.
1501.03496
Asher Berlin
Asher Berlin, Anthony DiFranzo, and Dan Hooper
A 3.55 keV Line from Exciting Dark Matter without a Hidden Sector
null
Phys. Rev. D 91, 075018 (2015)
10.1103/PhysRevD.91.075018
FERMILAB-PUB-15-009-A
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models in which dark matter particles can scatter into a slightly heavier state which promptly decays to the lighter state and a photon (known as eXciting Dark Matter, or XDM) have been shown to be capable of generating the 3.55 keV line observed from galaxy clusters, while suppressing the flux of such a line from smaller halos, including dwarf galaxies. In most of the XDM models discussed in the literature, this up-scattering is mediated by a new light particle, and dark matter annihilations proceed into pairs of this same light state. In these models, the dark matter and mediator effectively reside within a hidden sector, without sizable couplings to the Standard Model. In this paper, we explore a model of XDM that does not include a hidden sector. Instead, the dark matter both up-scatters and annihilates through the near resonant exchange of a $\mathcal{O}(10^2)$ GeV pseudoscalar with large Yukawa couplings to the dark matter and smaller, but non-neglibile, couplings to Standard Model fermions. The dark matter and the mediator are each mixtures of Standard Model singlets and $SU(2)_W$ doublets. We identify parameter space in which this model can simultaneously generate the 3.55 keV line and the gamma-ray excess observed from the Galactic Center, without conflicting with constraints from colliders, direct detection experiments, or observations of dwarf galaxies.
[ { "created": "Wed, 14 Jan 2015 21:00:12 GMT", "version": "v1" } ]
2015-04-29
[ [ "Berlin", "Asher", "" ], [ "DiFranzo", "Anthony", "" ], [ "Hooper", "Dan", "" ] ]
Models in which dark matter particles can scatter into a slightly heavier state which promptly decays to the lighter state and a photon (known as eXciting Dark Matter, or XDM) have been shown to be capable of generating the 3.55 keV line observed from galaxy clusters, while suppressing the flux of such a line from smaller halos, including dwarf galaxies. In most of the XDM models discussed in the literature, this up-scattering is mediated by a new light particle, and dark matter annihilations proceed into pairs of this same light state. In these models, the dark matter and mediator effectively reside within a hidden sector, without sizable couplings to the Standard Model. In this paper, we explore a model of XDM that does not include a hidden sector. Instead, the dark matter both up-scatters and annihilates through the near resonant exchange of a $\mathcal{O}(10^2)$ GeV pseudoscalar with large Yukawa couplings to the dark matter and smaller, but non-neglibile, couplings to Standard Model fermions. The dark matter and the mediator are each mixtures of Standard Model singlets and $SU(2)_W$ doublets. We identify parameter space in which this model can simultaneously generate the 3.55 keV line and the gamma-ray excess observed from the Galactic Center, without conflicting with constraints from colliders, direct detection experiments, or observations of dwarf galaxies.
2102.08601
Irinel Caprini
Irinel Caprini
Analyticity and Regge asymptotics in virtual Compton scattering on the nucleon
v2, minor changes, version accepted by EPJC
null
10.1140/epjc/s10052-021-09095-8
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We test the consistency of the data on the nucleon structure functions with analyticity and the Regge asymptotics of the virtual Compton amplitude. By solving a functional extremal problem, we derive an optimal lower bound on the maximum difference between the exact amplitude and the dominant Reggeon contribution for energies $\nu$ above a certain high value $\nu_h(Q^2)$. Considering in particular the difference of the amplitudes $T_1^\inel(\nu, Q^2)$ for the proton and neutron, we find that the lower bound decreases in an impressive way when $\nu_h(Q^2)$ is increased, and represents a very small fraction of the magnitude of the dominant Reggeon. While the method cannot rule out the hypothesis of a fixed Regge pole, the results indicate that the data on the structure function are consistent with an asymptotic behaviour given by leading Reggeon contributions. We also show that the minimum of the lower bound as a function of the subtraction constant $S_1^\inel(Q^2)$ provides a reasonable estimate of this quantity, in a frame similar, but not identical to the Reggeon dominance hypothesis.
[ { "created": "Wed, 17 Feb 2021 06:30:01 GMT", "version": "v1" }, { "created": "Mon, 29 Mar 2021 07:44:32 GMT", "version": "v2" } ]
2021-04-28
[ [ "Caprini", "Irinel", "" ] ]
We test the consistency of the data on the nucleon structure functions with analyticity and the Regge asymptotics of the virtual Compton amplitude. By solving a functional extremal problem, we derive an optimal lower bound on the maximum difference between the exact amplitude and the dominant Reggeon contribution for energies $\nu$ above a certain high value $\nu_h(Q^2)$. Considering in particular the difference of the amplitudes $T_1^\inel(\nu, Q^2)$ for the proton and neutron, we find that the lower bound decreases in an impressive way when $\nu_h(Q^2)$ is increased, and represents a very small fraction of the magnitude of the dominant Reggeon. While the method cannot rule out the hypothesis of a fixed Regge pole, the results indicate that the data on the structure function are consistent with an asymptotic behaviour given by leading Reggeon contributions. We also show that the minimum of the lower bound as a function of the subtraction constant $S_1^\inel(Q^2)$ provides a reasonable estimate of this quantity, in a frame similar, but not identical to the Reggeon dominance hypothesis.
1809.06240
Dmitry Chicherin
D. Chicherin, T. Gehrmann, J. M. Henn, N. A. Lo Presti, V. Mitev, P. Wasser
Analytic result for the nonplanar hexa-box integrals
22 pages, 4 figures, 3 ancillary files, published in JHEP
null
10.1007/JHEP03(2019)042
ZU-TH 35/18, MPP-2018-220, MITP/18-084, IPPP/18/75
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we analytically compute all master integrals for one of the two non-planar integral families for five-particle massless scattering at two loops. We first derive an integral basis of 73 integrals with constant leading singularities. We then construct the system of differential equations satisfied by them, and find that it is in canonical form. The solution space is in agreement with a recent conjecture for the non-planar pentagon alphabet. We fix the boundary constants of the differential equations by exploiting constraints from the absence of unphysical singularities. The solution of the differential equations in the Euclidean region is expressed in terms of iterated integrals. We cross-check the latter against previously known results in the literature, as well as with independent Mellin-Barnes calculations.
[ { "created": "Mon, 17 Sep 2018 14:29:22 GMT", "version": "v1" }, { "created": "Thu, 14 Mar 2019 18:31:27 GMT", "version": "v2" } ]
2019-03-18
[ [ "Chicherin", "D.", "" ], [ "Gehrmann", "T.", "" ], [ "Henn", "J. M.", "" ], [ "Presti", "N. A. Lo", "" ], [ "Mitev", "V.", "" ], [ "Wasser", "P.", "" ] ]
In this paper, we analytically compute all master integrals for one of the two non-planar integral families for five-particle massless scattering at two loops. We first derive an integral basis of 73 integrals with constant leading singularities. We then construct the system of differential equations satisfied by them, and find that it is in canonical form. The solution space is in agreement with a recent conjecture for the non-planar pentagon alphabet. We fix the boundary constants of the differential equations by exploiting constraints from the absence of unphysical singularities. The solution of the differential equations in the Euclidean region is expressed in terms of iterated integrals. We cross-check the latter against previously known results in the literature, as well as with independent Mellin-Barnes calculations.
0909.3974
Micha{\l} Silarski
M. Silarski, P. Moskal, E. Czerwinski, R. Czyzykiewicz, D. Gil, D. Grzonka, L. Jarczyk, B. Kamys, A. Khoukaz, J. Klaja, P. Klaja, W. Krzemien, W. Oelert, J. Ritman, T. Sefzick, M. Siemaszko, J. Smyrski, A. Taschner, P. Winter, M. Wolke, P. Wustner, M. Zielinski, W. Zipper, J. Zdebik
Generalized Dalitz Plot analysis of the near threshold pp-->ppK+K- reaction in view of the K+K- final state interaction
8 pages, 7 figures, to be published in Phys. Rev. C
Phys.Rev.C80:045202,2009
10.1103/PhysRevC.80.045202
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The excitation function for the $pp\to ppK^+K^-$ reaction revealed a significant enhancement close to threshold which may plausibly be assigned to the influence of the $pK^-$ and $K^+K^-$ final state interactions. In an improved reanalysis of COSY-11 data for the $pp\to ppK^+K^-$ reaction at excess energies of Q = 10 MeV and 28 MeV including the proton-K- interaction the enhancement is confirmed. Invariant mass distributions for the two- and three-particle subsystems allow to test at low excess energies the ansatz and parameters for the description of the interaction in the ppK+K- system as derived from the COSY-ANKE data. Finally, based for the first time on the low energy K+K- invariant mass distributions and the generalized Dalitz plot analysis, we estimate the scattering length for the K+K- interaction to be |Re(a_K^+K^-)| = 0.5 + 4.0 -0.5 fm and Im(a_K^+K^-) = 3.0 +- 3.0 fm.
[ { "created": "Tue, 22 Sep 2009 12:07:32 GMT", "version": "v1" } ]
2009-11-06
[ [ "Silarski", "M.", "" ], [ "Moskal", "P.", "" ], [ "Czerwinski", "E.", "" ], [ "Czyzykiewicz", "R.", "" ], [ "Gil", "D.", "" ], [ "Grzonka", "D.", "" ], [ "Jarczyk", "L.", "" ], [ "Kamys", "B.", ...
The excitation function for the $pp\to ppK^+K^-$ reaction revealed a significant enhancement close to threshold which may plausibly be assigned to the influence of the $pK^-$ and $K^+K^-$ final state interactions. In an improved reanalysis of COSY-11 data for the $pp\to ppK^+K^-$ reaction at excess energies of Q = 10 MeV and 28 MeV including the proton-K- interaction the enhancement is confirmed. Invariant mass distributions for the two- and three-particle subsystems allow to test at low excess energies the ansatz and parameters for the description of the interaction in the ppK+K- system as derived from the COSY-ANKE data. Finally, based for the first time on the low energy K+K- invariant mass distributions and the generalized Dalitz plot analysis, we estimate the scattering length for the K+K- interaction to be |Re(a_K^+K^-)| = 0.5 + 4.0 -0.5 fm and Im(a_K^+K^-) = 3.0 +- 3.0 fm.
hep-ph/9209249
Patrick O'Donnell
Patrick J. O'Donnell and Humphrey K.K. Tung
Exclusive Rare Decay $B\rightarrow K^{\ast}\gamma$
7 pages, UTPT-92-12, IP-ASTP-14, REVTEX
null
null
null
hep-ph
null
We show that the exclusive decay $B\rightarrow K^{\ast}\gamma$ can be related to the semileptonic decay $B\rightarrow\rho e\bar{\nu}$ using heavy-quark symmetry and $SU(3)$ flavor symmetry. A direct measurement of the $q^{2}$-spectrum for the semileptonic decay can provide relevant information for the exclusive rare decay.
[ { "created": "Thu, 17 Sep 1992 15:23:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "O'Donnell", "Patrick J.", "" ], [ "Tung", "Humphrey K. K.", "" ] ]
We show that the exclusive decay $B\rightarrow K^{\ast}\gamma$ can be related to the semileptonic decay $B\rightarrow\rho e\bar{\nu}$ using heavy-quark symmetry and $SU(3)$ flavor symmetry. A direct measurement of the $q^{2}$-spectrum for the semileptonic decay can provide relevant information for the exclusive rare decay.
hep-ph/0006337
Robert Buras
K.Boecker (MPP Munich)
Impact of Hadronic Axions on Black Hole Accretion Discs and Neutron Stars
Masters Thesis (TU Munich), 63 pp
null
null
null
hep-ph astro-ph
null
We re-examine the possibility of an astrophysically allowed KSVZ-type axion that has a strongly suppressed coupling to photons. We then investigate the impact of such ''hadronic axions'' on two classes of astrophysical objects: black hole accretion disc (BHAD) based gamma-ray bursts and isolated neutron-stars. Although our results are sensitive to details of the underlying models, we show that hadronic axions could in principle play an important role in the evolution of gamma-ray bursts and in the cooling behaviour of neutron stars.
[ { "created": "Thu, 29 Jun 2000 14:01:34 GMT", "version": "v1" } ]
2016-09-06
[ [ "Boecker", "K.", "", "MPP Munich" ] ]
We re-examine the possibility of an astrophysically allowed KSVZ-type axion that has a strongly suppressed coupling to photons. We then investigate the impact of such ''hadronic axions'' on two classes of astrophysical objects: black hole accretion disc (BHAD) based gamma-ray bursts and isolated neutron-stars. Although our results are sensitive to details of the underlying models, we show that hadronic axions could in principle play an important role in the evolution of gamma-ray bursts and in the cooling behaviour of neutron stars.
2004.05095
Gregory L. Johnson
Andrew Connelly, Gregory Johnson, Swagato Mukherjee, Vladimir Skokov
Universality driven analytic structure of QCD crossover: radius of convergence and QCD critical point
Quark Matter 2019 Conference Proceedings; Submitted to Nuclear Physics A
null
10.1016/j.nuclphysa.2020.121834
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent lattice QCD calculations show strong indications that the crossover of QCD at zero baryon chemical potential ($\mu_B$) is a remnant of the second order chiral phase transition. The non-universal parameters needed to map temperature $T$ and $\mu_B$ to the universal properties of the second order chiral phase transition were determined by lattice QCD calculations. Motivated by these advances, first, we discuss the analytic structure of the partition function -- the so-called Yang-Lee edge singularity -- in the QCD crossover regime, solely based on universal properties. Then, utilizing the lattice calculated non-universal parameters, we map this singularity to the real $T$ and complex $\mu_B$ plane, in order to find the radius of convergence for a Taylor series expansion of QCD partition function around $\mu_B=0$ in the QCD crossover regime. Our most important findings are: (i) An universality-based estimate of the radius of convergence around $\mu_B=0$; (ii) Universality and lattice QCD based constraints on the location of the QCD critical point in the $T-\mu_B$ plane.
[ { "created": "Fri, 10 Apr 2020 16:26:48 GMT", "version": "v1" } ]
2021-02-03
[ [ "Connelly", "Andrew", "" ], [ "Johnson", "Gregory", "" ], [ "Mukherjee", "Swagato", "" ], [ "Skokov", "Vladimir", "" ] ]
Recent lattice QCD calculations show strong indications that the crossover of QCD at zero baryon chemical potential ($\mu_B$) is a remnant of the second order chiral phase transition. The non-universal parameters needed to map temperature $T$ and $\mu_B$ to the universal properties of the second order chiral phase transition were determined by lattice QCD calculations. Motivated by these advances, first, we discuss the analytic structure of the partition function -- the so-called Yang-Lee edge singularity -- in the QCD crossover regime, solely based on universal properties. Then, utilizing the lattice calculated non-universal parameters, we map this singularity to the real $T$ and complex $\mu_B$ plane, in order to find the radius of convergence for a Taylor series expansion of QCD partition function around $\mu_B=0$ in the QCD crossover regime. Our most important findings are: (i) An universality-based estimate of the radius of convergence around $\mu_B=0$; (ii) Universality and lattice QCD based constraints on the location of the QCD critical point in the $T-\mu_B$ plane.
hep-ph/9901295
Guanghua Xu
Guanghua Xu
Studies of the Vector-Meson Mass Generation Scheme by Chiral Anomalies in two-Dimensional non-Abelian Gauge Theories
10 pages
null
null
null
hep-ph
null
Higher order effects of the two-dimensional non-Abelian gauge theories, in which the vector-meson mass is generated by chiral anomalies, will be studied. The $\beta$ function and the topological nature of the non-linear $\sigma$ model in the action and unitarity of the theory will be discussed.
[ { "created": "Wed, 13 Jan 1999 19:13:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Xu", "Guanghua", "" ] ]
Higher order effects of the two-dimensional non-Abelian gauge theories, in which the vector-meson mass is generated by chiral anomalies, will be studied. The $\beta$ function and the topological nature of the non-linear $\sigma$ model in the action and unitarity of the theory will be discussed.
hep-ph/9708259
Mikhail Dubinin
M. N. Dubinin (Moscow Univ., INP), H. S. Song (Seoul Univ., CTP)
Anomalous W boson production at HERA
25 pages, LaTeX, 2 figures LaTeX, 6 figures .ps, uses axodraw.sty
Phys.Rev.D57:2927-2939,1998
10.1103/PhysRevD.57.2927
null
hep-ph
null
We present the results of complete tree level calculation for W boson production processes e^- p -> e^- mu^+ nu_mu X and e^- p -> e^- mu^- nu_mubar X introducing anomalous WWgamma and WWZ couplings. Detailed results for the distributions of final state particles are obtained. In the region of small momentum transferred we calculate the contribution of hadronlike photon component in the structure function approach.
[ { "created": "Wed, 6 Aug 1997 14:55:04 GMT", "version": "v1" } ]
2011-07-19
[ [ "Dubinin", "M. N.", "", "Moscow Univ., INP" ], [ "Song", "H. S.", "", "Seoul Univ., CTP" ] ]
We present the results of complete tree level calculation for W boson production processes e^- p -> e^- mu^+ nu_mu X and e^- p -> e^- mu^- nu_mubar X introducing anomalous WWgamma and WWZ couplings. Detailed results for the distributions of final state particles are obtained. In the region of small momentum transferred we calculate the contribution of hadronlike photon component in the structure function approach.
hep-ph/9502214
null
Yoonbai Kim, Sho Tsujimaru and Koichi Yamawaki
Can the Nambu-Goldstone Boson Live on the Light-Front?
11pages, Latex file
Phys.Rev.Lett. 74 (1995) 4771-4774; Erratum-ibid. 75 (1995) 2632
10.1103/PhysRevLett.75.2632
DPNU-94-56, INS-rep.-1075
hep-ph hep-lat hep-th
null
We show that the Nambu-Goldstone(NG) boson restricted on the light-front(LF) can only exist if we regularize the theory by introducing the explicit breaking NG-boson mass $m_{\pi}$. The NG-boson zero mode, when integrated over the LF, must have a singular behavior $\sim 1/m^2_{\pi}$ in the symmetric limit of $m^2_{\pi}\rightarrow 0$. In the discretized LF quantization this peculiarity is clarified in terms of the zero-mode constraints in the linear $\sigma$ model. The LF charge annihilates the vacuum, while it is not conserved in the symmetric limit in the NG phase.
[ { "created": "Thu, 2 Feb 1995 07:34:00 GMT", "version": "v1" } ]
2016-09-01
[ [ "Kim", "Yoonbai", "" ], [ "Tsujimaru", "Sho", "" ], [ "Yamawaki", "Koichi", "" ] ]
We show that the Nambu-Goldstone(NG) boson restricted on the light-front(LF) can only exist if we regularize the theory by introducing the explicit breaking NG-boson mass $m_{\pi}$. The NG-boson zero mode, when integrated over the LF, must have a singular behavior $\sim 1/m^2_{\pi}$ in the symmetric limit of $m^2_{\pi}\rightarrow 0$. In the discretized LF quantization this peculiarity is clarified in terms of the zero-mode constraints in the linear $\sigma$ model. The LF charge annihilates the vacuum, while it is not conserved in the symmetric limit in the NG phase.
hep-ph/0608258
Alexander Kovner
A. Kovner, M. Lublinsky and H. Weigert
Treading on the cut: Semi inclusive observables at high energy
37 pages, 3 figures. A few remarks added. To appear in PRD
Phys.Rev.D74:114023,2006
10.1103/PhysRevD.74.114023
null
hep-ph
null
We develop the formalizm for calculating semi inclusive observables at high energy in the JIMWLK/KLWMIJ approach. We consider several examples including diffractive processes, elastic and inclusive over the target degrees of freedom, scattering with fixed total transverse momentum transfer and inclusive gluon production. We discuss evolution of these observables with respect to various rapidity variables involved in their definitions (total rapidity, rapidity gap, width of diffractive interval etc.). We also discuss the dipole model limit of these observables and derive closed simple (as opposed to functional) differential equations in this approximation. We point out that there are some interesting differences between the full JIMWLK/KLWMIJ evolution and the dipole model evolution of diffractive cross section. In particular we show that in the dipole approximation the target does not diffract beyond the valence rapidity interval, consistently with the intuition suggested by the Pomeron fan diagramms. On the other hand such diffractive processes do exist in the full JIMWLK/KLWMIJ approach, albeit suppressed by the factor 1/N_c^2.
[ { "created": "Wed, 23 Aug 2006 19:41:55 GMT", "version": "v1" }, { "created": "Sat, 25 Nov 2006 21:22:00 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kovner", "A.", "" ], [ "Lublinsky", "M.", "" ], [ "Weigert", "H.", "" ] ]
We develop the formalizm for calculating semi inclusive observables at high energy in the JIMWLK/KLWMIJ approach. We consider several examples including diffractive processes, elastic and inclusive over the target degrees of freedom, scattering with fixed total transverse momentum transfer and inclusive gluon production. We discuss evolution of these observables with respect to various rapidity variables involved in their definitions (total rapidity, rapidity gap, width of diffractive interval etc.). We also discuss the dipole model limit of these observables and derive closed simple (as opposed to functional) differential equations in this approximation. We point out that there are some interesting differences between the full JIMWLK/KLWMIJ evolution and the dipole model evolution of diffractive cross section. In particular we show that in the dipole approximation the target does not diffract beyond the valence rapidity interval, consistently with the intuition suggested by the Pomeron fan diagramms. On the other hand such diffractive processes do exist in the full JIMWLK/KLWMIJ approach, albeit suppressed by the factor 1/N_c^2.
hep-ph/9712294
Vladimir Baryshevsky
V. G. Baryshevsky (Nuclear Problems Institute, Minsk, Belarus)
The phenomena of the time-violating photon polarization plane and neutron spin rotation by a diffraction grating. New methods of measuring of the time-violating interactions
19 pages, uses article.sty
JHEP 9804:018,1998
10.1088/1126-6708/1998/04/018
null
hep-ph
null
It is shown, that the new phenomena of the T-violating photon polarization plane and neutron spin rotation appear under diffraction in a noncentrosymmetrical diffraction grating. The equations describing the T-violating photon scattering by a diffraction grating and neutron interaction with noncentrosymmetrical crystal have been obtained. These phenomena may be used for time-violating interactions investigation.
[ { "created": "Mon, 8 Dec 1997 11:32:32 GMT", "version": "v1" } ]
2009-10-30
[ [ "Baryshevsky", "V. G.", "", "Nuclear Problems Institute, Minsk, Belarus" ] ]
It is shown, that the new phenomena of the T-violating photon polarization plane and neutron spin rotation appear under diffraction in a noncentrosymmetrical diffraction grating. The equations describing the T-violating photon scattering by a diffraction grating and neutron interaction with noncentrosymmetrical crystal have been obtained. These phenomena may be used for time-violating interactions investigation.
hep-ph/0612168
Krishna Rajagopal
Hong Liu (MIT), Krishna Rajagopal (MIT), Urs Achim Wiedemann (CERN)
Wilson loops in heavy ion collisions and their calculation in AdS/CFT
61 pages, 8 figures. Note added discussing relation between our work and that in several papers that have appeared recently. References added
JHEP 0703:066,2007
10.1088/1126-6708/2007/03/066
MIT-CTP-3794, CERN-PH-TH/2006-257
hep-ph hep-th nucl-th
null
Expectation values of Wilson loops define the nonperturbative properties of the hot medium produced in heavy ion collisions that arise in the analysis of both radiative parton energy loss and quarkonium suppression. We use the AdS/CFT correspondence to calculate the expectation values of such Wilson loops in the strongly coupled plasma of N=4 super Yang-Mills (SYM) theory, allowing for the possibility that the plasma may be moving with some collective flow velocity as is the case in heavy ion collisions. We obtain the N=4 SYM values of the jet quenching parameter $\hat q$, which describes the energy loss of a hard parton in QCD, and of the velocity-dependence of the quark-antiquark screening length for a moving dipole as a function of the angle between its velocity and its orientation. We show that if the quark-gluon plasma is flowing with velocity v_f at an angle theta with respect to the trajectory of a hard parton, the jet quenching parameter $\hat q$ is modified by a factor gamma_f(1-v_f cos theta), and show that this result applies in QCD as in N=4 SYM. We discuss the relevance of the lessons we are learning from all these calculations to heavy ion collisions at RHIC and at the LHC. Furthermore, we discuss the relation between our results and those obtained in other theories with gravity duals, showing in particular that the ratio between $\hat q$ in any two conformal theories with gravity duals is the square root of the ratio of their central charges. This leads us to conjecture that in nonconformal theories $\hat q$ defines a quantity that always decreases along renormalization group trajectories and allows us to use our calculation of $\hat q$ in N=4 SYM to make a conjecture for its value in QCD.
[ { "created": "Wed, 13 Dec 2006 20:24:16 GMT", "version": "v1" }, { "created": "Fri, 26 Jan 2007 18:22:50 GMT", "version": "v2" } ]
2010-10-27
[ [ "Liu", "Hong", "", "MIT" ], [ "Rajagopal", "Krishna", "", "MIT" ], [ "Wiedemann", "Urs Achim", "", "CERN" ] ]
Expectation values of Wilson loops define the nonperturbative properties of the hot medium produced in heavy ion collisions that arise in the analysis of both radiative parton energy loss and quarkonium suppression. We use the AdS/CFT correspondence to calculate the expectation values of such Wilson loops in the strongly coupled plasma of N=4 super Yang-Mills (SYM) theory, allowing for the possibility that the plasma may be moving with some collective flow velocity as is the case in heavy ion collisions. We obtain the N=4 SYM values of the jet quenching parameter $\hat q$, which describes the energy loss of a hard parton in QCD, and of the velocity-dependence of the quark-antiquark screening length for a moving dipole as a function of the angle between its velocity and its orientation. We show that if the quark-gluon plasma is flowing with velocity v_f at an angle theta with respect to the trajectory of a hard parton, the jet quenching parameter $\hat q$ is modified by a factor gamma_f(1-v_f cos theta), and show that this result applies in QCD as in N=4 SYM. We discuss the relevance of the lessons we are learning from all these calculations to heavy ion collisions at RHIC and at the LHC. Furthermore, we discuss the relation between our results and those obtained in other theories with gravity duals, showing in particular that the ratio between $\hat q$ in any two conformal theories with gravity duals is the square root of the ratio of their central charges. This leads us to conjecture that in nonconformal theories $\hat q$ defines a quantity that always decreases along renormalization group trajectories and allows us to use our calculation of $\hat q$ in N=4 SYM to make a conjecture for its value in QCD.
2211.14587
Pengxuan Zhu
Jun Zhao, Jingya Zhu, Pengxuan Zhu and Rui Zhu
Light higgsino scenario confronted with muon g-2
20 pages, 8 figures and 1 table. Upgraded to the published version
null
10.1103/PhysRevD.107.055030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Light higgsinos below several hundred GeV are favored or required by the naturalness of low energy supersymmetry. If only higgsinos are light while other sparticles are sufficiently heavy, we have the so-called light higgsino scenario. Confronted with the muon $g-2$ data, this scenario is examined in this work. Since in this scenario the LSP (lightest sparticle) is higgsino-like, we need to also consider the dark matter constraints. Assuming a light higgsino mass parameter $\mu$ in the range of 100-400 GeV while gaugino mass parameters above TeV, we explore the parameter space under the muon $g-2$ data and the dark matter constraints. We find that, to explain the muon $g-2$ anomaly at $2\sigma$, the winos and sleptons are respectively upper bounded by 3 TeV and 800 GeV. In this case, we find that the light higgsino-like dark matter can sizably scatter with nucleon and thus the allowed parameter space can be covered almost fully by the future LZ dark matter detection project. We also perform a Monte Carlo simulation to figure out the potential of HL-LHC to detect the light sleptons in this scenario. It turns out that compared with the current LHC limits, the HL-LHC can further cover a part of the parameter space.
[ { "created": "Sat, 26 Nov 2022 15:08:25 GMT", "version": "v1" }, { "created": "Wed, 22 Mar 2023 06:16:49 GMT", "version": "v2" } ]
2023-03-23
[ [ "Zhao", "Jun", "" ], [ "Zhu", "Jingya", "" ], [ "Zhu", "Pengxuan", "" ], [ "Zhu", "Rui", "" ] ]
Light higgsinos below several hundred GeV are favored or required by the naturalness of low energy supersymmetry. If only higgsinos are light while other sparticles are sufficiently heavy, we have the so-called light higgsino scenario. Confronted with the muon $g-2$ data, this scenario is examined in this work. Since in this scenario the LSP (lightest sparticle) is higgsino-like, we need to also consider the dark matter constraints. Assuming a light higgsino mass parameter $\mu$ in the range of 100-400 GeV while gaugino mass parameters above TeV, we explore the parameter space under the muon $g-2$ data and the dark matter constraints. We find that, to explain the muon $g-2$ anomaly at $2\sigma$, the winos and sleptons are respectively upper bounded by 3 TeV and 800 GeV. In this case, we find that the light higgsino-like dark matter can sizably scatter with nucleon and thus the allowed parameter space can be covered almost fully by the future LZ dark matter detection project. We also perform a Monte Carlo simulation to figure out the potential of HL-LHC to detect the light sleptons in this scenario. It turns out that compared with the current LHC limits, the HL-LHC can further cover a part of the parameter space.
2201.10499
Victor Goncalves
Ya-Ping Xie, Victor P. Goncalves
Exclusive processes in $ep$ collisions at the EIC and LHeC: A closer look on the predictions of saturation models
16 pages, 8 figures, 2 tables
null
10.1103/PhysRevD.105.014033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exclusive production of vector mesons and photons in $ep$ collisions is investigated considering three phenomenological saturation models based on distinct assumptions for the treatment of the dipole - hadron scattering amplitude. The latest high precision HERA data for the reduced and vector meson cross sections are used to update the saturation model proposed by Marquet - Peschanski - Soyez (MPS), which predicts that the saturation model is dependent of the squared momentum transfer $t$. The MPS predictions for the photon virtuality, energy and $t$ - dependencies of the exclusive $\rho$, $J/\Psi$ and DVCS cross sections are presented and a detailed comparison with the results derived using the impact parameter saturation models is performed. Our results indicate that a future experimental analysis of the $t$ - distribution $d\sigma/dt$ for exclusive processes in the kinematical range that will covered by the EIC and LHeC, considering the distinct photon polarizations and large values of $t$, will be able to discriminate between the distinct approaches for the QCD dynamics at high energies.
[ { "created": "Tue, 25 Jan 2022 17:48:35 GMT", "version": "v1" } ]
2022-02-09
[ [ "Xie", "Ya-Ping", "" ], [ "Goncalves", "Victor P.", "" ] ]
The exclusive production of vector mesons and photons in $ep$ collisions is investigated considering three phenomenological saturation models based on distinct assumptions for the treatment of the dipole - hadron scattering amplitude. The latest high precision HERA data for the reduced and vector meson cross sections are used to update the saturation model proposed by Marquet - Peschanski - Soyez (MPS), which predicts that the saturation model is dependent of the squared momentum transfer $t$. The MPS predictions for the photon virtuality, energy and $t$ - dependencies of the exclusive $\rho$, $J/\Psi$ and DVCS cross sections are presented and a detailed comparison with the results derived using the impact parameter saturation models is performed. Our results indicate that a future experimental analysis of the $t$ - distribution $d\sigma/dt$ for exclusive processes in the kinematical range that will covered by the EIC and LHeC, considering the distinct photon polarizations and large values of $t$, will be able to discriminate between the distinct approaches for the QCD dynamics at high energies.
1510.07991
Arsham Farzinnia
Arsham Farzinnia
Phenomenology of the Renormalizable Coloron Model
10 pages, 5 figures. Contribution to the 18th International Conference From the Planck Scale to the Electroweak Scale, 25-29 May 2015 (Ioannina, Greece), published by Proceedings of Science
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The renormalizable coloron model constitutes the minimal extension of the standard model (SM) color sector to $SU(3)_{1c} \times SU(3)_{2c}$, with the spontaneous symmetry breaking of the extended gauge group to the diagonal QCD facilitated by the renormalizable operators. It predicts the existence of the beyond the SM massive color-octet gauge bosons (colorons), colored and uncolored scalar degrees of freedom, as well as potential spectator fermions necessary for anomaly-cancelation purposes. Furthermore, keeping the ordinary chiral quark charge assignments under the extended color gauge group in their most general form, the framework (effectively) captures a large class of models available within the literature. This contribution summarizes the current formal and phenomenological constraints on the free parameter space of the theory, as well as the LHC $\sqrt s = 14$ TeV prospects for discovering its heavy scalar. The model is well-constrained and highly predictive; in particular, it is shown that the parameter space can be thoroughly probed by the LHC and the next generation hadron colliders, making it a promising beyond the SM candidate for exploration. In addition, the significance of the NLO corrections to the coloron production cross section are discussed.
[ { "created": "Tue, 27 Oct 2015 17:10:17 GMT", "version": "v1" } ]
2015-10-28
[ [ "Farzinnia", "Arsham", "" ] ]
The renormalizable coloron model constitutes the minimal extension of the standard model (SM) color sector to $SU(3)_{1c} \times SU(3)_{2c}$, with the spontaneous symmetry breaking of the extended gauge group to the diagonal QCD facilitated by the renormalizable operators. It predicts the existence of the beyond the SM massive color-octet gauge bosons (colorons), colored and uncolored scalar degrees of freedom, as well as potential spectator fermions necessary for anomaly-cancelation purposes. Furthermore, keeping the ordinary chiral quark charge assignments under the extended color gauge group in their most general form, the framework (effectively) captures a large class of models available within the literature. This contribution summarizes the current formal and phenomenological constraints on the free parameter space of the theory, as well as the LHC $\sqrt s = 14$ TeV prospects for discovering its heavy scalar. The model is well-constrained and highly predictive; in particular, it is shown that the parameter space can be thoroughly probed by the LHC and the next generation hadron colliders, making it a promising beyond the SM candidate for exploration. In addition, the significance of the NLO corrections to the coloron production cross section are discussed.
0709.3362
George Lazarides
G. Lazarides, A. Vamvasakis (Aristotle U., Thessaloniki)
Standard-smooth hybrid inflation
11 pages including 2 figures, uses Revtex, version to appear in Phys. Rev. D
Phys.Rev.D76:123514,2007
10.1103/PhysRevD.76.123514
UT-STPD-4/07
hep-ph astro-ph
null
We consider the extended supersymmetric Pati-Salam model which, for mu>0 and universal boundary conditions, succeeds to yield experimentally acceptable b-quark masses by moderately violating Yukawa unification. It is known that this model can lead to new shifted or new smooth hybrid inflation. We show that a successful two-stage inflationary scenario can be realized within this model based only on renormalizable superpotential interactions. The cosmological scales exit the horizon during the first stage of inflation, which is of the standard hybrid type and takes place along the trivial flat direction with the inflaton driven by radiative corrections. Spectral indices compatible with the recent data can be achieved in global supersymmetry or minimal supergravity by restricting the number of e-foldings of our present horizon during the first inflationary stage. The additional e-foldings needed for solving the horizon and flatness problems are naturally provided by a second stage of inflation, which occurs mainly along the built-in new smooth hybrid inflationary path appearing right after the destabilization of the trivial flat direction at its critical point. Monopoles are formed at the end of the first stage of inflation and are, subsequently, diluted by the second stage of inflation to become utterly negligible in the present universe for almost all (for all) the allowed values of the parameters in the case of global supersymmetry (minimal supergravity).
[ { "created": "Fri, 21 Sep 2007 07:34:31 GMT", "version": "v1" }, { "created": "Sun, 16 Dec 2007 10:32:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lazarides", "G.", "", "Aristotle U., Thessaloniki" ], [ "Vamvasakis", "A.", "", "Aristotle U., Thessaloniki" ] ]
We consider the extended supersymmetric Pati-Salam model which, for mu>0 and universal boundary conditions, succeeds to yield experimentally acceptable b-quark masses by moderately violating Yukawa unification. It is known that this model can lead to new shifted or new smooth hybrid inflation. We show that a successful two-stage inflationary scenario can be realized within this model based only on renormalizable superpotential interactions. The cosmological scales exit the horizon during the first stage of inflation, which is of the standard hybrid type and takes place along the trivial flat direction with the inflaton driven by radiative corrections. Spectral indices compatible with the recent data can be achieved in global supersymmetry or minimal supergravity by restricting the number of e-foldings of our present horizon during the first inflationary stage. The additional e-foldings needed for solving the horizon and flatness problems are naturally provided by a second stage of inflation, which occurs mainly along the built-in new smooth hybrid inflationary path appearing right after the destabilization of the trivial flat direction at its critical point. Monopoles are formed at the end of the first stage of inflation and are, subsequently, diluted by the second stage of inflation to become utterly negligible in the present universe for almost all (for all) the allowed values of the parameters in the case of global supersymmetry (minimal supergravity).
0907.0906
Tony Gherghetta
Yanou Cui, Tony Gherghetta, James D. Wells
Emergent Electroweak Symmetry Breaking with Composite W, Z Bosons
39 pages, 4 figures
null
10.1088/1126-6708/2009/11/080
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model of electroweak symmetry breaking in a warped extra dimension where electroweak symmetry is broken at the UV (or Planck) scale. An underlying conformal symmetry is broken at the IR (or TeV) scale generating masses for the electroweak gauge bosons without invoking a Higgs mechanism. By the AdS/CFT correspondence the W,Z bosons are identified as composite states of a strongly-coupled gauge theory, suggesting that electroweak symmetry breaking is an emergent phenomenon at the IR scale. The model satisfies electroweak precision tests with reasonable fits to the S and T parameter. In particular the T parameter is sufficiently suppressed since the model naturally admits a custodial SU(2) symmetry. The composite nature of the W,Z-bosons provide a novel possibility of unitarizing WW scattering via form factor suppression. Constraints from LEP and the Tevatron as well as discovery opportunities at the LHC are discussed for these composite electroweak gauge bosons.
[ { "created": "Mon, 6 Jul 2009 02:24:59 GMT", "version": "v1" } ]
2015-05-13
[ [ "Cui", "Yanou", "" ], [ "Gherghetta", "Tony", "" ], [ "Wells", "James D.", "" ] ]
We present a model of electroweak symmetry breaking in a warped extra dimension where electroweak symmetry is broken at the UV (or Planck) scale. An underlying conformal symmetry is broken at the IR (or TeV) scale generating masses for the electroweak gauge bosons without invoking a Higgs mechanism. By the AdS/CFT correspondence the W,Z bosons are identified as composite states of a strongly-coupled gauge theory, suggesting that electroweak symmetry breaking is an emergent phenomenon at the IR scale. The model satisfies electroweak precision tests with reasonable fits to the S and T parameter. In particular the T parameter is sufficiently suppressed since the model naturally admits a custodial SU(2) symmetry. The composite nature of the W,Z-bosons provide a novel possibility of unitarizing WW scattering via form factor suppression. Constraints from LEP and the Tevatron as well as discovery opportunities at the LHC are discussed for these composite electroweak gauge bosons.
hep-ph/0512305
J.D. Vergados
J. D. Vergados (Unuversity of Ioannina, Ioannina, Greece)
Direct SUSY Dark Matter Detection- Constraints on the Spin Cross Section
15 LaTex pages, 21 figures, 2 tables
null
null
null
hep-ph
null
The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Thus the direct dark matter detection, consisting of detecting the recoiling nucleus, is central to particle physics and cosmology. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). The relevant cross sections arise out of two mechanisms: i) The coherent mode, due to the scalar interaction and ii) The spin contribution arising from the axial current. In this paper we will focus on the spin contribution, which maybe important, especially for light targets.
[ { "created": "Thu, 22 Dec 2005 18:37:04 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2005 22:00:02 GMT", "version": "v2" }, { "created": "Sun, 25 Dec 2005 18:20:08 GMT", "version": "v3" }, { "created": "Mon, 9 Jan 2006 20:19:13 GMT", "version": "v4" } ]
2007-05-23
[ [ "Vergados", "J. D.", "", "Unuversity of Ioannina, Ioannina, Greece" ] ]
The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Thus the direct dark matter detection, consisting of detecting the recoiling nucleus, is central to particle physics and cosmology. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). The relevant cross sections arise out of two mechanisms: i) The coherent mode, due to the scalar interaction and ii) The spin contribution arising from the axial current. In this paper we will focus on the spin contribution, which maybe important, especially for light targets.
hep-ph/9906421
Fred Olness
R. N. Mohapatra, F. Olness, R. Stroynowski, V. L. Teplitz
Searching for Strongly Interacting Massive Particles (SIMPs)
RevTeX, 10 pages, 3 figures; Minor updates to match published version
Phys. Rev. D 60, 115013 (1999)
10.1103/PhysRevD.60.115013
UMD-PP-99-118
hep-ph
null
We consider laboratory experiments that can detect stable, neutral strongly interacting massive particles (SIMPs). We explore the SIMP annihilation cross section from its minimum value (restricted by cosmological bounds) to the barn range, and vary the mass values from a GeV to a TeV. We calculate, as a function of the SIMP-nucleon cross section, the minimum nucleon number A for which there should be binding in a nucleus. We consider accelerator mass spectrometry with a gold (A=200) target, and compute the likely abundance of anomalous gold nuclei if stable neutral SIMPs exist. We also consider the prospects and problems of detecting such particles at the Tevatron. We estimate optimistically that such detection might be possible for SIMPs with SIMP-nucleon cross sections larger than 0.1 millibarn and masses between 25 and 50 GeV.
[ { "created": "Thu, 17 Jun 1999 18:56:24 GMT", "version": "v1" }, { "created": "Thu, 30 Sep 1999 19:22:44 GMT", "version": "v2" } ]
2016-08-25
[ [ "Mohapatra", "R. N.", "" ], [ "Olness", "F.", "" ], [ "Stroynowski", "R.", "" ], [ "Teplitz", "V. L.", "" ] ]
We consider laboratory experiments that can detect stable, neutral strongly interacting massive particles (SIMPs). We explore the SIMP annihilation cross section from its minimum value (restricted by cosmological bounds) to the barn range, and vary the mass values from a GeV to a TeV. We calculate, as a function of the SIMP-nucleon cross section, the minimum nucleon number A for which there should be binding in a nucleus. We consider accelerator mass spectrometry with a gold (A=200) target, and compute the likely abundance of anomalous gold nuclei if stable neutral SIMPs exist. We also consider the prospects and problems of detecting such particles at the Tevatron. We estimate optimistically that such detection might be possible for SIMPs with SIMP-nucleon cross sections larger than 0.1 millibarn and masses between 25 and 50 GeV.
1706.00437
Sebastian Pa{\ss}ehr
Florian Domingo, Peter Drechsel, and Sebastian Pa{\ss}ehr
On-Shell neutral Higgs bosons in the NMSSM with complex parameters
28 pages, 11 figures
null
10.1140/epjc/s10052-017-5104-2
DESY--17--067; IFT--UAM/CSIC--17--042
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Next-to-Minimal Supersymmetric Standard model (NMSSM) appears as an interesting candidate for the interpretation of the Higgs-measurement at the LHC and as a rich framework embedding physics beyond the Standard Model. We consider the renormalization of the Higgs sector of this model in its $\mathcal{CP}$-violating version, and propose a renormalization scheme for the calculation of on-shell Higgs masses. Moreover, the connection between the physical states and the tree-level ones is no longer trivial at the radiative level: a proper description of the corresponding transition thus proves necessary in order to calculate Higgs production and decays at a consistent loop order. After discussing these formal aspects, we compare the results of our mass calculation to the output of existing tools. We also study the relevance of the on-shell transition-matrix in the example of the $h_i \to \tau^+ \tau^-$ width. We find deviations between our full prescription and popular approximations that can exceed $10\%$.
[ { "created": "Thu, 1 Jun 2017 18:00:06 GMT", "version": "v1" }, { "created": "Tue, 25 Jul 2017 12:02:57 GMT", "version": "v2" } ]
2017-09-13
[ [ "Domingo", "Florian", "" ], [ "Drechsel", "Peter", "" ], [ "Paßehr", "Sebastian", "" ] ]
The Next-to-Minimal Supersymmetric Standard model (NMSSM) appears as an interesting candidate for the interpretation of the Higgs-measurement at the LHC and as a rich framework embedding physics beyond the Standard Model. We consider the renormalization of the Higgs sector of this model in its $\mathcal{CP}$-violating version, and propose a renormalization scheme for the calculation of on-shell Higgs masses. Moreover, the connection between the physical states and the tree-level ones is no longer trivial at the radiative level: a proper description of the corresponding transition thus proves necessary in order to calculate Higgs production and decays at a consistent loop order. After discussing these formal aspects, we compare the results of our mass calculation to the output of existing tools. We also study the relevance of the on-shell transition-matrix in the example of the $h_i \to \tau^+ \tau^-$ width. We find deviations between our full prescription and popular approximations that can exceed $10\%$.
1805.00088
Paolo Parotto
R. Bellwied, J. Noronha-Hostler, P. Parotto, I. Portillo Vazquez, C. Ratti, J. M. Stafford
Freeze-out temperature from net-Kaon fluctuations at RHIC
5 pages, 3 figures
Phys. Rev. C 99, 034912 (2019)
10.1103/PhysRevC.99.034912
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare the mean-over-variance ratio of the net-kaon distribution calculated within a state-of-the-art hadron resonance gas model to the latest experimental data from the Beam Energy Scan at RHIC by the STAR collaboration. Our analysis indicates that it is not possible to reproduce the experimental results using the freeze-out parameters from the existing combined fit of net-proton and net-electric charge mean-over-variance. The strange mesons need about 10-15 MeV higher temperatures than the light hadrons at the highest collision energies. In view of the future $\Lambda$ fluctuation measurements, we predict the $\Lambda$ variance-over-mean and skewness-times-variance at the light and strange chemical freeze-out parameters. We observe that the $\Lambda$ fluctuations are sensitive to the difference in the freeze-out temperatures established in this analysis. Our results have implications for other phenomenological models in the field of relativistic heavy ion collisions.
[ { "created": "Mon, 30 Apr 2018 20:29:34 GMT", "version": "v1" } ]
2019-04-03
[ [ "Bellwied", "R.", "" ], [ "Noronha-Hostler", "J.", "" ], [ "Parotto", "P.", "" ], [ "Vazquez", "I. Portillo", "" ], [ "Ratti", "C.", "" ], [ "Stafford", "J. M.", "" ] ]
We compare the mean-over-variance ratio of the net-kaon distribution calculated within a state-of-the-art hadron resonance gas model to the latest experimental data from the Beam Energy Scan at RHIC by the STAR collaboration. Our analysis indicates that it is not possible to reproduce the experimental results using the freeze-out parameters from the existing combined fit of net-proton and net-electric charge mean-over-variance. The strange mesons need about 10-15 MeV higher temperatures than the light hadrons at the highest collision energies. In view of the future $\Lambda$ fluctuation measurements, we predict the $\Lambda$ variance-over-mean and skewness-times-variance at the light and strange chemical freeze-out parameters. We observe that the $\Lambda$ fluctuations are sensitive to the difference in the freeze-out temperatures established in this analysis. Our results have implications for other phenomenological models in the field of relativistic heavy ion collisions.
2008.02668
Sergei Vergeles
N.N. Nikolaev and S.N. Vergeles
General relativity and precision tests of fundamental symmetries
29 pages, To be published in Gribov-90 Memorial Volume: Field Theory, Symmetry, and Related Topics. Editors Yuri L. Dokshitzer, Peter Levai. Arpad Lukacs and Julia Nyiri, World Scientific, 2020
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Search for the Electric Dipole Moment of nuclear particles is at the forefront of incessant quest for CP violation beyond Standard Model. The ultimate target is to reach a sensitivity to the electric dipole moment of neutrons, protons, deuterons etc. at the level of $\sim 10^{-15}$ nuclear magnetons. Defying the common lore on weakness of gravity, spurious signals induced by curved space-time in the gravity field of the rotating Earth become quite substantial at such a daunting sensitivity. We review the recent development in the field with an emphasis on the geometric magnetic field in pure electrostatic systems at rest on the rotating Earth.
[ { "created": "Wed, 5 Aug 2020 09:26:23 GMT", "version": "v1" } ]
2020-08-07
[ [ "Nikolaev", "N. N.", "" ], [ "Vergeles", "S. N.", "" ] ]
Search for the Electric Dipole Moment of nuclear particles is at the forefront of incessant quest for CP violation beyond Standard Model. The ultimate target is to reach a sensitivity to the electric dipole moment of neutrons, protons, deuterons etc. at the level of $\sim 10^{-15}$ nuclear magnetons. Defying the common lore on weakness of gravity, spurious signals induced by curved space-time in the gravity field of the rotating Earth become quite substantial at such a daunting sensitivity. We review the recent development in the field with an emphasis on the geometric magnetic field in pure electrostatic systems at rest on the rotating Earth.
hep-ph/9907270
null
I.I. Bigi
Memo on Extracting |V(cb)| and |V(ub)/V(cb)| from semileptonic B decays
Contributed to the Informal Workshop on the Derivation of |V(cb)| and |V(ub)|, CERN, May 28 - June 2, 1999, 19 pages, LATEX
null
null
null
hep-ph
null
Heavy Quark Expansions for semileptonic decays of beauty hadrons are briefly reviewed. I analyze how $|V(cb)|$ can be extracted from the semileptonic width of $B$ mesons, the average semileptonic width of all weakly decaying beauty hadrons and from $B \ra l \nu D^*$ at zero recoil. Special attention is paid to present theoretical uncertainties (including correlations among them) and on how to reduce them in the future. Finally I will comment on theoretical uncertainties in $|V(ub)/V(cb)|$.
[ { "created": "Wed, 7 Jul 1999 15:46:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bigi", "I. I.", "" ] ]
Heavy Quark Expansions for semileptonic decays of beauty hadrons are briefly reviewed. I analyze how $|V(cb)|$ can be extracted from the semileptonic width of $B$ mesons, the average semileptonic width of all weakly decaying beauty hadrons and from $B \ra l \nu D^*$ at zero recoil. Special attention is paid to present theoretical uncertainties (including correlations among them) and on how to reduce them in the future. Finally I will comment on theoretical uncertainties in $|V(ub)/V(cb)|$.
0810.4429
Naoto Tanji
Naoto Tanji
Dynamical view of pair creation in uniform electric and magnetic fields
57pages, 44figures. v2: typos corrected, references added, to appear in Ann.Phys
Annals Phys.324:1691-1736,2009
10.1016/j.aop.2009.03.012
UT-Komaba/08-15
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pair creation in a uniform classical electromagnetic field (Schwinger mechanism) is studied focusing on the time evolution of the distribution of created particles. The time evolution of the distribution in time-dependent fields is also presented as well as effects of back reaction. Motivated by the Glasma flux tube, which may be formed at the initial stage of heavy-ion collisions, we investigate effects of a magnetic field parallel to an electric field, and find that the magnetic field makes the evolution of a fermion system faster.
[ { "created": "Fri, 24 Oct 2008 14:06:27 GMT", "version": "v1" }, { "created": "Tue, 12 May 2009 10:33:28 GMT", "version": "v2" } ]
2010-04-15
[ [ "Tanji", "Naoto", "" ] ]
Pair creation in a uniform classical electromagnetic field (Schwinger mechanism) is studied focusing on the time evolution of the distribution of created particles. The time evolution of the distribution in time-dependent fields is also presented as well as effects of back reaction. Motivated by the Glasma flux tube, which may be formed at the initial stage of heavy-ion collisions, we investigate effects of a magnetic field parallel to an electric field, and find that the magnetic field makes the evolution of a fermion system faster.
1001.1129
Seung Woo Ham
S. W. Ham, Seong-A Shim, S. K. Oh
Electroweak baryogenesis in the MSSM with vector-like quarks
16 pages, 3 figures, 2 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the minimal supersymmetric standard model (MSSM), a strongly first-order electroweak phase transition (EWPT) is only possible in a confined parameter region where one of the scalar top quarks is lighter than the top quark and the other one is as heavy as the SUSY breaking scale. If the MSSM is enlarged to accommodate vector-like quarks and their superpartners, we find that the strongly first-order EWPT is possible without requiring light scalar top quark at the one-loop level, in the limit where the lightest scalar Higgs boson of the MSSM behaves like the Higgs boson of the standard model and the other Higgs bosons are all as heavy as the SUSY breaking scale. The strength of the first-order EWPT is found to be dependent on the mass of the lightest neutral Higgs boson and the mixing effects of the vector-like scalar quarks.
[ { "created": "Thu, 7 Jan 2010 18:36:22 GMT", "version": "v1" }, { "created": "Mon, 12 Apr 2010 09:16:03 GMT", "version": "v2" } ]
2010-04-13
[ [ "Ham", "S. W.", "" ], [ "Shim", "Seong-A", "" ], [ "Oh", "S. K.", "" ] ]
In the minimal supersymmetric standard model (MSSM), a strongly first-order electroweak phase transition (EWPT) is only possible in a confined parameter region where one of the scalar top quarks is lighter than the top quark and the other one is as heavy as the SUSY breaking scale. If the MSSM is enlarged to accommodate vector-like quarks and their superpartners, we find that the strongly first-order EWPT is possible without requiring light scalar top quark at the one-loop level, in the limit where the lightest scalar Higgs boson of the MSSM behaves like the Higgs boson of the standard model and the other Higgs bosons are all as heavy as the SUSY breaking scale. The strength of the first-order EWPT is found to be dependent on the mass of the lightest neutral Higgs boson and the mixing effects of the vector-like scalar quarks.