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hep-ph/0003253
Per Osland
A.A. Babich (Gomel), P. Osland (Bergen), A.A. Pankov (Gomel), N. Paver (Trieste)
Contact interaction probes at the Linear Collider with polarized electron and positron beams
1+15 pages, LaTeX2e, including 7 figures
Phys.Lett.B481:263-274,2000
10.1016/S0370-2693(00)00456-1
UTS-DFT-00-01
hep-ph
null
For contact-interaction searches at the Linear Collider, we discuss the advantages of polarizing both the electron and the positron beams as compared with polarizing only the electron beam. In particular, for the processes e^+e^-\to \mu^+\mu^-, \tau^+\tau^-, b\bar{b} and c\bar{c} at a future e^+e^- collider with \sqrt{s}=0.5 TeV we derive model-independent bounds on the four-fermion contact interaction parameters from studies of the helicity cross sections.
[ { "created": "Sun, 26 Mar 2000 15:37:41 GMT", "version": "v1" } ]
2011-01-25
[ [ "Babich", "A. A.", "", "Gomel" ], [ "Osland", "P.", "", "Bergen" ], [ "Pankov", "A. A.", "", "Gomel" ], [ "Paver", "N.", "", "Trieste" ] ]
For contact-interaction searches at the Linear Collider, we discuss the advantages of polarizing both the electron and the positron beams as compared with polarizing only the electron beam. In particular, for the processes e^+e^-\to \mu^+\mu^-, \tau^+\tau^-, b\bar{b} and c\bar{c} at a future e^+e^- collider with \sqrt{s}=0.5 TeV we derive model-independent bounds on the four-fermion contact interaction parameters from studies of the helicity cross sections.
1309.6877
Martin Hoferichter
Martin Hoferichter, Gilberto Colangelo, Massimiliano Procura, Peter Stoffer
Virtual photon-photon scattering
5 pages, 3 figures, Proceedings for the International Workshop on e^+e^- collisions from phi to psi 2013, Rome, Italy, September 9-12, 2013
null
10.1142/S2010194514604001
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e^+e^- --> hadrons. We review the main difficulties that impede such an approach for light-by-light scattering and identify the required ingredients from experiment. Amongst those, the most critical one is the scattering of two virtual photons into meson pairs. We analyze the analytic structure of the process gamma^* gamma^* --> pi pi and show that the usual Muskhelishvili-Omnes representation can be amended in such a way as to remain valid even in the presence of anomalous thresholds.
[ { "created": "Thu, 26 Sep 2013 12:54:59 GMT", "version": "v1" } ]
2015-06-17
[ [ "Hoferichter", "Martin", "" ], [ "Colangelo", "Gilberto", "" ], [ "Procura", "Massimiliano", "" ], [ "Stoffer", "Peter", "" ] ]
Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e^+e^- --> hadrons. We review the main difficulties that impede such an approach for light-by-light scattering and identify the required ingredients from experiment. Amongst those, the most critical one is the scattering of two virtual photons into meson pairs. We analyze the analytic structure of the process gamma^* gamma^* --> pi pi and show that the usual Muskhelishvili-Omnes representation can be amended in such a way as to remain valid even in the presence of anomalous thresholds.
2311.17989
Joel Jones-Perez
L. Duarte, J. Jones-P\'erez, C. Manrique-Chavil
Bounding the Dimension-5 Seesaw Portal with Non-Pointing Photon Searches
27 pages, 3 figures; v2: improved discussion, results unchanged. Version accepted for publication in JHEP
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The addition of $d=5$ operators to the Seesaw model leads to the Dimension-5 Seesaw Portal. Here, two new operators provide interactions for the heavy sterile neutrinos. In particular, the Higgs boson can have a large branching ratio into two heavy neutrinos, meaning that these states can be searched for at the LHC. Moreover, the heavy neutrinos can now decay dominantly into light neutrinos and photons. If the heavy neutrinos are long-lived, then searches for delayed, non-pointing photons can constrain the model. In this work, we carry out a detailed recast of an ATLAS search for such displaced photons, triggered by a charged lepton produced in association to the Higgs, placing bounds on the branching ratio for Higgs decay into two heavy neutrinos as low as 2%.
[ { "created": "Wed, 29 Nov 2023 19:00:00 GMT", "version": "v1" }, { "created": "Tue, 7 May 2024 13:41:23 GMT", "version": "v2" } ]
2024-05-08
[ [ "Duarte", "L.", "" ], [ "Jones-Pérez", "J.", "" ], [ "Manrique-Chavil", "C.", "" ] ]
The addition of $d=5$ operators to the Seesaw model leads to the Dimension-5 Seesaw Portal. Here, two new operators provide interactions for the heavy sterile neutrinos. In particular, the Higgs boson can have a large branching ratio into two heavy neutrinos, meaning that these states can be searched for at the LHC. Moreover, the heavy neutrinos can now decay dominantly into light neutrinos and photons. If the heavy neutrinos are long-lived, then searches for delayed, non-pointing photons can constrain the model. In this work, we carry out a detailed recast of an ATLAS search for such displaced photons, triggered by a charged lepton produced in association to the Higgs, placing bounds on the branching ratio for Higgs decay into two heavy neutrinos as low as 2%.
0904.4489
Abbas Kenan Ciftci
R. Ciftci, A. K. Ciftci
A Comperative Study of the Anomalous Single Production of the Fourth Generation Quarks at ep and gamma-p Colliders
12 pages, 4 tables, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose some channels for the possible observation of anomalous interactions of the fourth standard model generation quarks at the Large Hadron Collider based ep and gamma-p colliders. Namely, u_4 (d_4) -> q gamma and u_4 (d_4) -> q Z -> q l^+ l^- decay processes are considered. Signatures for signals and corresponding standard model backgrounds are investigated at both colliders comperatively. The lowest necessary luminosities to observe these processes and the achievable values of the anomalous coupling strengths are determined. It is shown that the gamma-p collider is advantageous compare to the ep collider.
[ { "created": "Tue, 28 Apr 2009 21:25:24 GMT", "version": "v1" } ]
2009-04-30
[ [ "Ciftci", "R.", "" ], [ "Ciftci", "A. K.", "" ] ]
We propose some channels for the possible observation of anomalous interactions of the fourth standard model generation quarks at the Large Hadron Collider based ep and gamma-p colliders. Namely, u_4 (d_4) -> q gamma and u_4 (d_4) -> q Z -> q l^+ l^- decay processes are considered. Signatures for signals and corresponding standard model backgrounds are investigated at both colliders comperatively. The lowest necessary luminosities to observe these processes and the achievable values of the anomalous coupling strengths are determined. It is shown that the gamma-p collider is advantageous compare to the ep collider.
1512.04225
Tanja Geib
Tanja Geib and Alexander Merle
Conversions of Bound Muons: Lepton Flavour Violation from Doubly Charged Scalars
36 pages, 12 figures, Content matches published version (up to small stylistic ambiguities)
Phys. Rev. D 93, 055039 (2016)
10.1103/PhysRevD.93.055039
MPP-2015-282
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the first detailed computation of the conversion of a bound muon into an electron mediated by a doubly charged $SU(2)$ singlet scalar. Although such particles are not too exotic, up to now their contribution to $\mu$-$e$ conversion is unknown. We close this gap by presenting a detailed calculation, which will allow the reader not only to fully comprehend the discussion but also to generalise our results to similar cases if needed. We furthermore compare the predictions, for both the general case and for an example model featuring a neutrino mass at 2-loop level, to current experimental data and future sensitivities. We show that, depending on the explicit values of the couplings as well as on the actual future limits on the branching ratio, $\mu$-$e$ conversion may potentially yield a lower limit on the doubly charged singlet scalar mass which is stronger than what could be obtained by colliders. Our results considerably strengthen the case for low-energy lepton flavour violation searches being a very valuable addition to collider experiments.
[ { "created": "Mon, 14 Dec 2015 09:24:31 GMT", "version": "v1" }, { "created": "Fri, 30 Sep 2016 09:47:13 GMT", "version": "v2" } ]
2016-10-03
[ [ "Geib", "Tanja", "" ], [ "Merle", "Alexander", "" ] ]
We present the first detailed computation of the conversion of a bound muon into an electron mediated by a doubly charged $SU(2)$ singlet scalar. Although such particles are not too exotic, up to now their contribution to $\mu$-$e$ conversion is unknown. We close this gap by presenting a detailed calculation, which will allow the reader not only to fully comprehend the discussion but also to generalise our results to similar cases if needed. We furthermore compare the predictions, for both the general case and for an example model featuring a neutrino mass at 2-loop level, to current experimental data and future sensitivities. We show that, depending on the explicit values of the couplings as well as on the actual future limits on the branching ratio, $\mu$-$e$ conversion may potentially yield a lower limit on the doubly charged singlet scalar mass which is stronger than what could be obtained by colliders. Our results considerably strengthen the case for low-energy lepton flavour violation searches being a very valuable addition to collider experiments.
hep-ph/0404006
Felix Nagel
O. Nachtmann, F. Nagel, M. Pospischil
Anomalous gauge-boson couplings and the Higgs-boson mass
50 pages, 4 figures; version to appear in EPJC
Eur.Phys.J.C42:139-161,2005
10.1140/epjc/s2005-02202-5
HD-THEP-04-14
hep-ph
null
We study anomalous gauge-boson couplings induced by a locally SU(2) x U(1) invariant effective Lagrangian containing ten operators of dimension six built from the boson fields of the Standard Model (SM) before spontaneous symmetry breaking (SSB). After SSB some operators lead to new three- and four-gauge-boson interactions, some contribute to the diagonal and off-diagonal kinetic terms of the gauge bosons and to the mass terms of the W and Z bosons. This requires a renormalisation of the gauge-boson fields, which, in turn, modifies the charged- and neutral-current interactions, although none of the additional operators contain fermion fields. Bounds on the anomalous couplings from electroweak precision measurements at LEP and SLD are correlated with the Higgs-boson mass m_H. Rather moderate values of anomalous couplings allow m_H up to 500 GeV. At a future linear collider the triple-gauge-boson couplings gammaWW and ZWW can be measured in the reaction e+e- --> WW. We compare three approaches to anomalous gauge-boson couplings: the form-factor approach, the addition of anomalous coupling terms to the SM Lagrangian after and, as outlined above, before SSB. The translation of the bounds on the couplings from one approach to another is not straightforward. We show that it can be done for the process e+e- --> WW by defining new effective ZWW couplings.
[ { "created": "Thu, 1 Apr 2004 16:22:24 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2005 10:24:17 GMT", "version": "v2" } ]
2011-09-13
[ [ "Nachtmann", "O.", "" ], [ "Nagel", "F.", "" ], [ "Pospischil", "M.", "" ] ]
We study anomalous gauge-boson couplings induced by a locally SU(2) x U(1) invariant effective Lagrangian containing ten operators of dimension six built from the boson fields of the Standard Model (SM) before spontaneous symmetry breaking (SSB). After SSB some operators lead to new three- and four-gauge-boson interactions, some contribute to the diagonal and off-diagonal kinetic terms of the gauge bosons and to the mass terms of the W and Z bosons. This requires a renormalisation of the gauge-boson fields, which, in turn, modifies the charged- and neutral-current interactions, although none of the additional operators contain fermion fields. Bounds on the anomalous couplings from electroweak precision measurements at LEP and SLD are correlated with the Higgs-boson mass m_H. Rather moderate values of anomalous couplings allow m_H up to 500 GeV. At a future linear collider the triple-gauge-boson couplings gammaWW and ZWW can be measured in the reaction e+e- --> WW. We compare three approaches to anomalous gauge-boson couplings: the form-factor approach, the addition of anomalous coupling terms to the SM Lagrangian after and, as outlined above, before SSB. The translation of the bounds on the couplings from one approach to another is not straightforward. We show that it can be done for the process e+e- --> WW by defining new effective ZWW couplings.
1111.4530
Shuo Yang
Shuo Yang and Qi-Shu Yan
Searching for Heavy Charged Higgs Boson with Jet Substructure at the LHC
27 pages, 10 figures, 7 tables; v2: some typos corrected and references added; v3: discussion added, Fig.10 and Table7 updated, version published in JHEP
JHEP 1202 (2012) 074
10.1007/JHEP02(2012)074
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the heavy charged Higgs boson (from 800 GeV to 1500 GeV in this study) in production associated with a top quark at the LHC with the collision energy $\sqrt{s}=14$ TeV. Such a heavy charged Higgs boson can dominantly decay into a top quark and a bottom quark due to its large Yukawa couplings, like in MSSM. To suppress background events and to confirm the signal, we reconstruct the mass bumps of the heavy charged Higgs boson and the associated top quark. For this purpose, we propose a hybrid-R reconstruction method which utilizes the top tagging technique, a jet substructure technique developed for highly boosted massive particles. By using the full hadronic mode of $p p \to H^{\pm} t \to t tb$ as a test field, we find that this method can greatly reduce the combinatorics in the full reconstruction and can successfully reduce background events down to a controlled level. The sensitivity of LHC to the heavy charged Higgs boson with two $b$ taggings is studied and a $9.5\sigma$ significance can be achieved when $m_{H^\pm} =1 \textrm{TeV}$.
[ { "created": "Sat, 19 Nov 2011 03:33:23 GMT", "version": "v1" }, { "created": "Wed, 30 Nov 2011 03:28:16 GMT", "version": "v2" }, { "created": "Thu, 8 Mar 2012 01:24:58 GMT", "version": "v3" } ]
2015-06-03
[ [ "Yang", "Shuo", "" ], [ "Yan", "Qi-Shu", "" ] ]
We study the heavy charged Higgs boson (from 800 GeV to 1500 GeV in this study) in production associated with a top quark at the LHC with the collision energy $\sqrt{s}=14$ TeV. Such a heavy charged Higgs boson can dominantly decay into a top quark and a bottom quark due to its large Yukawa couplings, like in MSSM. To suppress background events and to confirm the signal, we reconstruct the mass bumps of the heavy charged Higgs boson and the associated top quark. For this purpose, we propose a hybrid-R reconstruction method which utilizes the top tagging technique, a jet substructure technique developed for highly boosted massive particles. By using the full hadronic mode of $p p \to H^{\pm} t \to t tb$ as a test field, we find that this method can greatly reduce the combinatorics in the full reconstruction and can successfully reduce background events down to a controlled level. The sensitivity of LHC to the heavy charged Higgs boson with two $b$ taggings is studied and a $9.5\sigma$ significance can be achieved when $m_{H^\pm} =1 \textrm{TeV}$.
0704.1616
Michael Chanowitz
Michael S. Chanowitz
Reply to Comment on "Chiral suppression of scalar glueball decay"
null
Phys.Rev.Lett.98:149104,2007
10.1103/PhysRevLett.98.149104
null
hep-ph
null
Reply to the comment of Chao, He, and Ma.
[ { "created": "Thu, 12 Apr 2007 16:45:36 GMT", "version": "v1" } ]
2008-11-26
[ [ "Chanowitz", "Michael S.", "" ] ]
Reply to the comment of Chao, He, and Ma.
1809.03071
Dmytro Oliinychenko
Dmytro Oliinychenko, Long-Gang Pang, Hannah Elfner and Volker Koch
Deuterons at LHC: "snowballs in hell" via hydrodynamics and hadronic afterburner
13 pages, 10 figures, version accepted to publication
Phys. Rev. C 99, 044907 (2019)
10.1103/PhysRevC.99.044907
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The deuteron yield in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV is consistent with thermal production at a freeze-out temperature of $T = 155$ MeV. The existence of deuterons with binding energy of 2.2 MeV at this temperature was described as "snowballs in hell". We provide a microscopic explanation of this phenomenon, utilizing relativistic hydrodynamics and switching to a hadronic afterburner at the above mentioned temperature of $T = 155$ MeV. The measured deuteron $p_T$-spectra and coalescence parameter $B_2(p_T)$ are reproduced without free parameters, only by implementing experimentally known cross-sections of deuteron reactions with hadrons, most importantly $\pi d \leftrightarrow \pi n p$.
[ { "created": "Mon, 10 Sep 2018 00:55:33 GMT", "version": "v1" }, { "created": "Fri, 12 Apr 2019 00:00:45 GMT", "version": "v2" } ]
2019-04-15
[ [ "Oliinychenko", "Dmytro", "" ], [ "Pang", "Long-Gang", "" ], [ "Elfner", "Hannah", "" ], [ "Koch", "Volker", "" ] ]
The deuteron yield in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV is consistent with thermal production at a freeze-out temperature of $T = 155$ MeV. The existence of deuterons with binding energy of 2.2 MeV at this temperature was described as "snowballs in hell". We provide a microscopic explanation of this phenomenon, utilizing relativistic hydrodynamics and switching to a hadronic afterburner at the above mentioned temperature of $T = 155$ MeV. The measured deuteron $p_T$-spectra and coalescence parameter $B_2(p_T)$ are reproduced without free parameters, only by implementing experimentally known cross-sections of deuteron reactions with hadrons, most importantly $\pi d \leftrightarrow \pi n p$.
hep-ph/0308119
Werner Rodejohann
W. Rodejohann
Neutrino mass matrices leaving no trace
16 pages, 2 figures
Phys.Lett. B579 (2004) 127-139
10.1016/j.physletb.2003.10.113
SISSA 73/2003/EP
hep-ph
null
We point attention to the fact that in SO(10) models with non-canonical (type II) see-saw mechanism and exact b-tau unification the trace of the neutrino mass matrix is very small, in fact practically zero. This has the advantage of being a basis independent feature. Taking a vanishing trace as input, immediate phenomenological consequences for the values of the neutrino masses, the CP phases or the predictions for neutrinoless double beta decay arise. We analyze the impact of the zero trace condition for the normal and inverted mass ordering and in case of CP conservation and violation. Simple candidate mass matrices with (close to) vanishing trace and non-zero U_{e3} are proposed. We also compare the results with the other most simple basis independent property, namely a vanishing determinant.
[ { "created": "Mon, 11 Aug 2003 16:09:36 GMT", "version": "v1" } ]
2010-04-05
[ [ "Rodejohann", "W.", "" ] ]
We point attention to the fact that in SO(10) models with non-canonical (type II) see-saw mechanism and exact b-tau unification the trace of the neutrino mass matrix is very small, in fact practically zero. This has the advantage of being a basis independent feature. Taking a vanishing trace as input, immediate phenomenological consequences for the values of the neutrino masses, the CP phases or the predictions for neutrinoless double beta decay arise. We analyze the impact of the zero trace condition for the normal and inverted mass ordering and in case of CP conservation and violation. Simple candidate mass matrices with (close to) vanishing trace and non-zero U_{e3} are proposed. We also compare the results with the other most simple basis independent property, namely a vanishing determinant.
hep-ph/9707385
Susan Gardner
S. Gardner and H.B. O'Connell (Kentucky)
Rho-Omega Mixing and the Pion Form Factor in the Time-like Region
20 pages, REVTeX, epsfig, 2 ps figures, minor changes
Phys.Rev.D57:2716-2726,1998; Erratum-ibid.D62:019903,2000; Phys.Rev.D62:019903,2000
10.1103/PhysRevD.57.2716 10.1103/PhysRevD.62.019903
UK/TP 97-10
hep-ph nucl-th
null
We determine the magnitude, phase, and $s$-dependence of $\rho$-$\omega$ ``mixing'' in the pion form factor in the time-like region through fits to $e^+e^- \ra \pi^+ \pi^-$ data. The associated systematic errors in these quantities, arising from the functional form used to fit the $\rho$ resonance, are small. The systematic errors in the $\rho$ mass and width, however, are larger than previously estimated.
[ { "created": "Fri, 18 Jul 1997 02:57:17 GMT", "version": "v1" }, { "created": "Fri, 17 Apr 1998 02:05:03 GMT", "version": "v2" } ]
2014-11-17
[ [ "Gardner", "S.", "", "Kentucky" ], [ "O'Connell", "H. B.", "", "Kentucky" ] ]
We determine the magnitude, phase, and $s$-dependence of $\rho$-$\omega$ ``mixing'' in the pion form factor in the time-like region through fits to $e^+e^- \ra \pi^+ \pi^-$ data. The associated systematic errors in these quantities, arising from the functional form used to fit the $\rho$ resonance, are small. The systematic errors in the $\rho$ mass and width, however, are larger than previously estimated.
hep-ph/9607353
Toshio Tsukamoto
Toshio Tsukamoto (Saga Univ.) and Yoshimasa Kurihara (KEK)
Single-W production to test triple gauge boson couplings at LEP
revised version, to appear in Physics Letters B
Phys.Lett. B389 (1996) 162-168
10.1016/S0370-2693(96)01240-3
SAGA-HE-106, KEK-Preprint 96-83, KEK-CP-048
hep-ph
null
We present a study of single-W production ($e^+e^-\to e^-\bar{\nu}_e W^+$) as a new probe of the anomalous couplings at the LEP energy region. We introduce simple cuts to separate the single-W process from W-pair production and have performed cross-section calculations using 4-fermion generator ``grc4f''. The cross-section of the single-W process is found to be large enough to detect at LEP experiments in the near future. In addition, a high sensitivity to the anomalous coupling of the $WW\gamma$ vertex is expected since the amplitude of the $WW\gamma$ diagram makes a dominant contribution in this process. We have found that the cross-section measurement of the single-W process in the LEP2 energy region can give complementary bounds on the anomalous couplings to those obtained from W-pair analysis.
[ { "created": "Wed, 17 Jul 1996 19:00:03 GMT", "version": "v1" }, { "created": "Thu, 12 Sep 1996 17:27:33 GMT", "version": "v2" } ]
2009-10-28
[ [ "Tsukamoto", "Toshio", "", "Saga Univ." ], [ "Kurihara", "Yoshimasa", "", "KEK" ] ]
We present a study of single-W production ($e^+e^-\to e^-\bar{\nu}_e W^+$) as a new probe of the anomalous couplings at the LEP energy region. We introduce simple cuts to separate the single-W process from W-pair production and have performed cross-section calculations using 4-fermion generator ``grc4f''. The cross-section of the single-W process is found to be large enough to detect at LEP experiments in the near future. In addition, a high sensitivity to the anomalous coupling of the $WW\gamma$ vertex is expected since the amplitude of the $WW\gamma$ diagram makes a dominant contribution in this process. We have found that the cross-section measurement of the single-W process in the LEP2 energy region can give complementary bounds on the anomalous couplings to those obtained from W-pair analysis.
1802.06730
Alexander Ochirov Dr.
Alexander Ochirov
Helicity amplitudes for QCD with massive quarks
v3 conventions tweaked to match further work by author, supersedes journal version
JHEP 1804 (2018) 089
10.1007/JHEP04(2018)089
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The novel massive spinor-helicity formalism of Arkani-Hamed, Huang and Huang provides an elegant way to calculate scattering amplitudes in quantum chromodynamics for arbitrary quark spin projections. In this note we compute two families of tree-level QCD amplitudes with one massive quark pair and n-2 gluons. The two cases include all gluons with identical helicity and one opposite-helicity gluon being color-adjacent to one of the quarks. Our results naturally incorporate the previously known amplitudes for both quark spins quantized along one of the gluonic momenta. In the all-multiplicity formulae presented here the spin quantization axes can be tuned at will, which includes the case of the definite-helicity quark states.
[ { "created": "Mon, 19 Feb 2018 17:52:08 GMT", "version": "v1" }, { "created": "Thu, 12 Apr 2018 10:55:17 GMT", "version": "v2" }, { "created": "Sun, 16 Dec 2018 16:51:44 GMT", "version": "v3" } ]
2018-12-18
[ [ "Ochirov", "Alexander", "" ] ]
The novel massive spinor-helicity formalism of Arkani-Hamed, Huang and Huang provides an elegant way to calculate scattering amplitudes in quantum chromodynamics for arbitrary quark spin projections. In this note we compute two families of tree-level QCD amplitudes with one massive quark pair and n-2 gluons. The two cases include all gluons with identical helicity and one opposite-helicity gluon being color-adjacent to one of the quarks. Our results naturally incorporate the previously known amplitudes for both quark spins quantized along one of the gluonic momenta. In the all-multiplicity formulae presented here the spin quantization axes can be tuned at will, which includes the case of the definite-helicity quark states.
0706.4119
Eef van Beveren
Eef van Beveren and George Rupp
Relating multichannel scattering and production amplitudes in a microscopic OZI-based model
16 pages, 3 figures, plain LaTeX;
Annals Phys.323:1215-1229,2008
10.1016/j.aop.2007.11.012
null
hep-ph
null
Relations between scattering and production amplitudes are studied in a microscopic multichannel model for meson-meson scattering, with coupling to confined quark-antiquark channels. Overlapping resonances and a proper threshold behaviour are treated exactly in the model. Under the spectator assumption, it is found that the two-particle production amplitude shares a common denominator with the elastic scattering amplitude, besides a numerator consisting of a linear combination of all elastic and some inelastic matrix elements. The coefficients in these linear combinations are shown to be generally complex. Finally, the standard operator expressions relating production and scattering amplitudes, viz. A=T/V and Im(A)=T*A, are fulfilled, while in the small-coupling limit the usual isobar model is recovered.
[ { "created": "Thu, 28 Jun 2007 17:19:59 GMT", "version": "v1" }, { "created": "Tue, 30 Oct 2007 12:51:23 GMT", "version": "v2" } ]
2011-07-19
[ [ "van Beveren", "Eef", "" ], [ "Rupp", "George", "" ] ]
Relations between scattering and production amplitudes are studied in a microscopic multichannel model for meson-meson scattering, with coupling to confined quark-antiquark channels. Overlapping resonances and a proper threshold behaviour are treated exactly in the model. Under the spectator assumption, it is found that the two-particle production amplitude shares a common denominator with the elastic scattering amplitude, besides a numerator consisting of a linear combination of all elastic and some inelastic matrix elements. The coefficients in these linear combinations are shown to be generally complex. Finally, the standard operator expressions relating production and scattering amplitudes, viz. A=T/V and Im(A)=T*A, are fulfilled, while in the small-coupling limit the usual isobar model is recovered.
1712.01244
Fei Wang
Junjie Cao, Lei Feng, Xiaofei Guo, Liangliang Shang, Fei Wang, Peiwen Wu, Lei Zu
Explaining the DAMPE data with scalar dark matter and gauged $U(1)_{L_e-L_\mu}$ interaction
15 pages, 4 figures
Eur. Phys. J. C (2018) 78: 198
10.1140/epjc/s10052-018-5678-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the peak structure observed by recent DAMPE experiment in $e^+e^-$ cosmic-ray spectrum, we consider a scalar dark matter (DM) model with gauged $U(1)_{L_e-L_\mu}$ symmetry, which is the most economical anomaly-free theory to potentially explain the peak by DM annihilation in nearby subhalo. We utilize the process $\chi \chi \to Z^\prime Z^\prime \to l \bar{l} l^\prime \bar{l}^\prime$, where $\chi$, $Z^\prime$, $l^{(\prime)}$ denote the scalar DM, the new gauge boson and $l^{(\prime)} =e, \mu$, respectively, to generate the $e^+e^-$ spectrum. By fitting the predicted spectrum to the experimental data, we obtain the favored DM mass range $m_\chi \simeq 3060^{+80}_{-100} \, {\rm GeV}$ and $\Delta m \equiv m_\chi - m_{Z^\prime} \lesssim 14 \, {\rm GeV}$ at $68\%$ Confidence Level (C.L.). Furthermore, we determine the parameter space of the model which can explain the peak and meanwhile satisfy the constraints from DM relic abundance, DM direct detection and the collider bounds. We conclude that the model we consider can account for the peak, although there exists a tension with the constraints from the LEP-II bound on $m_{Z^\prime}$ arising from the cross section measurement of $e^+e^- \to Z^{\prime\ast} \to e^+ e^-$.
[ { "created": "Mon, 4 Dec 2017 18:38:44 GMT", "version": "v1" }, { "created": "Tue, 9 Jan 2018 17:40:45 GMT", "version": "v2" }, { "created": "Thu, 8 Feb 2018 17:05:14 GMT", "version": "v3" }, { "created": "Mon, 4 Jun 2018 18:29:26 GMT", "version": "v4" } ]
2018-06-06
[ [ "Cao", "Junjie", "" ], [ "Feng", "Lei", "" ], [ "Guo", "Xiaofei", "" ], [ "Shang", "Liangliang", "" ], [ "Wang", "Fei", "" ], [ "Wu", "Peiwen", "" ], [ "Zu", "Lei", "" ] ]
Inspired by the peak structure observed by recent DAMPE experiment in $e^+e^-$ cosmic-ray spectrum, we consider a scalar dark matter (DM) model with gauged $U(1)_{L_e-L_\mu}$ symmetry, which is the most economical anomaly-free theory to potentially explain the peak by DM annihilation in nearby subhalo. We utilize the process $\chi \chi \to Z^\prime Z^\prime \to l \bar{l} l^\prime \bar{l}^\prime$, where $\chi$, $Z^\prime$, $l^{(\prime)}$ denote the scalar DM, the new gauge boson and $l^{(\prime)} =e, \mu$, respectively, to generate the $e^+e^-$ spectrum. By fitting the predicted spectrum to the experimental data, we obtain the favored DM mass range $m_\chi \simeq 3060^{+80}_{-100} \, {\rm GeV}$ and $\Delta m \equiv m_\chi - m_{Z^\prime} \lesssim 14 \, {\rm GeV}$ at $68\%$ Confidence Level (C.L.). Furthermore, we determine the parameter space of the model which can explain the peak and meanwhile satisfy the constraints from DM relic abundance, DM direct detection and the collider bounds. We conclude that the model we consider can account for the peak, although there exists a tension with the constraints from the LEP-II bound on $m_{Z^\prime}$ arising from the cross section measurement of $e^+e^- \to Z^{\prime\ast} \to e^+ e^-$.
1709.09860
German F. R. Sborlini
German F. R. Sborlini, Felix Driencourt-Mangin, German Rodrigo
On the universal structure of Higgs amplitudes mediated by heavy particles
5 pages, no figures. Contribution to the Proceedings of the EPS-HEP 2017 Conference
PoS(EPS-HEP2017)767
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the calculation of the one-loop corrections to $H \to \gamma \gamma$ and $g g \to H$ within the four-dimensional unsubtraction/loop-tree duality (FDU/LTD) approach. The fact that these corrections are both IR and UV finite is not enough to perform the computation without a proper regularization of the intermediate steps. We show how the FDU/LTD method unambiguously leads to the proper result with a pure four-dimensional representation of the loop amplitude. Moreover, this method allows us to obtain very compact expressions which share the same functional structure independently of the particles circulating the loop. Besides this, asymptotic expansions for the low and high mass regime naturally arise as a consequence of the smoothness of the integrands obtained to describe the amplitudes.
[ { "created": "Thu, 28 Sep 2017 09:13:45 GMT", "version": "v1" } ]
2017-09-29
[ [ "Sborlini", "German F. R.", "" ], [ "Driencourt-Mangin", "Felix", "" ], [ "Rodrigo", "German", "" ] ]
We describe the calculation of the one-loop corrections to $H \to \gamma \gamma$ and $g g \to H$ within the four-dimensional unsubtraction/loop-tree duality (FDU/LTD) approach. The fact that these corrections are both IR and UV finite is not enough to perform the computation without a proper regularization of the intermediate steps. We show how the FDU/LTD method unambiguously leads to the proper result with a pure four-dimensional representation of the loop amplitude. Moreover, this method allows us to obtain very compact expressions which share the same functional structure independently of the particles circulating the loop. Besides this, asymptotic expansions for the low and high mass regime naturally arise as a consequence of the smoothness of the integrands obtained to describe the amplitudes.
2310.05744
Andreas Vogt
S. Moch (Hamburg U., Inst. Theor. Phys. II), B. Ruijl (ETH, Zurich), T. Ueda (Juntendo U.), J. Vermaseren (Nikhef, Amsterdam), A. Vogt (Liverpool U., Dept. Math.)
Additional moments and x-space approximations of four-loop splitting functions in QCD
14 pages, 3 figures. Analytical and numerical results in ancillary FORM and Fortran files
null
null
DESY-23-150, Nikhef 23-016, LTH 1354
hep-ph
http://creativecommons.org/licenses/by/4.0/
We have extended our previous computations of the even-N moments of the flavour-singlet four-loop splitting functions to N = 12 for the pure-singlet quark case and N = 10 for all other cases. These results, obtained using physical quantities in inclusive deep-inelastic scattering, have been and will be used to validate conceptionally much more challenging determinations of these splitting functions from off-shell operator matrix elements (OMEs). For the quark-gluon and gluon-gluon splitting functions, which have yet to be computed to higher N using OMEs, we construct approximations based on our moments and endpoint constraints, where we present new large-x results for the gluon-gluon case. These approximations facilitate an approximate N^3LO evolution of parton distributions which are sufficiently accurate outside the region of small momentum fractions x.
[ { "created": "Mon, 9 Oct 2023 14:19:08 GMT", "version": "v1" } ]
2023-10-10
[ [ "Moch", "S.", "", "Hamburg U., Inst. Theor. Phys. II" ], [ "Ruijl", "B.", "", "ETH, Zurich" ], [ "Ueda", "T.", "", "Juntendo U." ], [ "Vermaseren", "J.", "", "Nikhef, Amsterdam" ], [ "Vogt", "A.", "", "Liverpool\n U., Dept. Math." ] ]
We have extended our previous computations of the even-N moments of the flavour-singlet four-loop splitting functions to N = 12 for the pure-singlet quark case and N = 10 for all other cases. These results, obtained using physical quantities in inclusive deep-inelastic scattering, have been and will be used to validate conceptionally much more challenging determinations of these splitting functions from off-shell operator matrix elements (OMEs). For the quark-gluon and gluon-gluon splitting functions, which have yet to be computed to higher N using OMEs, we construct approximations based on our moments and endpoint constraints, where we present new large-x results for the gluon-gluon case. These approximations facilitate an approximate N^3LO evolution of parton distributions which are sufficiently accurate outside the region of small momentum fractions x.
2011.05505
Lei Chang
Lei Chang and Minghui Ding
The rainbow modified-ladder approximation and degenerate pion
9 pages, 4 figures
Phys. Rev. D 103, 074001 (2021)
10.1103/PhysRevD.103.074001
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Correlation functions can be described by the corresponding equations, $viz.$, gap equation for quark propagator and the inhomogeneous Bethe-Salpeter equation for vector dressed-fermion-Abelian-gauge-boson vertex in which specific truncations have to be implemented. The general vector and axial-vector Ward-Green-Takahashi identities require these correlation functions to be interconnected, in consequence of this, truncations made must be controlled consistently. It turns out that if the rainbow approximation is assumed in gap equation, the scattering kernel in Bethe-Salpeter equation can adopt the ladder approximation, which is one of the most basic attempts to truncate the scattering kernel. Additionally, a modified-ladder approximation is also found to be a possible symmetry-preserving truncation scheme. As an illustration of this approximation for application a treatment of pion is included. Pion mass and decay constant are found to be degenerate in ladder and modified-ladder approximations, even though the Bethe-Salpeter amplitude are with apparent distinction. The justification for the modified-ladder approximation is examined with the help of the Gell-Mann-Oakes-Renner (GMOR) relation.
[ { "created": "Wed, 11 Nov 2020 01:55:44 GMT", "version": "v1" } ]
2021-04-07
[ [ "Chang", "Lei", "" ], [ "Ding", "Minghui", "" ] ]
Correlation functions can be described by the corresponding equations, $viz.$, gap equation for quark propagator and the inhomogeneous Bethe-Salpeter equation for vector dressed-fermion-Abelian-gauge-boson vertex in which specific truncations have to be implemented. The general vector and axial-vector Ward-Green-Takahashi identities require these correlation functions to be interconnected, in consequence of this, truncations made must be controlled consistently. It turns out that if the rainbow approximation is assumed in gap equation, the scattering kernel in Bethe-Salpeter equation can adopt the ladder approximation, which is one of the most basic attempts to truncate the scattering kernel. Additionally, a modified-ladder approximation is also found to be a possible symmetry-preserving truncation scheme. As an illustration of this approximation for application a treatment of pion is included. Pion mass and decay constant are found to be degenerate in ladder and modified-ladder approximations, even though the Bethe-Salpeter amplitude are with apparent distinction. The justification for the modified-ladder approximation is examined with the help of the Gell-Mann-Oakes-Renner (GMOR) relation.
hep-ph/0403177
Hans Weda
J. Weda (University of Utrecht, The Netherlands) and J.A. Tjon (Jefferson Lab, USA)
Effects of perturbative exchanges in a QCD-string model
37 pages Revtex with 2 figures, to be published in Phys. Atom. Nucl. dedicated to the 70th Birthday of Yu. A. Simonov
Phys.Atom.Nucl.68:591-608,2005; Yad.Fiz.68:621-639,2005
10.1134/1.1903089
ITP-UU-04/08
hep-ph nucl-th
null
The QCD-string model for baryons derived by Simonov and used for the calculation of baryon magnetic moments in a previous paper is extended to include also perturbative gluon and meson exchanges. The mass spectrum of the baryon multiplet is studied. For the meson interaction either the pseudoscalar or pseudovector coupling is used. Predictions are compared with the experimental data. Besides these exchanges the influence of excited quark orbitals on the baryon ground state are considered by performing a multichannel calculation. The nucleon-Delta splitting increases due to the mixing of higher quark states while the baryon magnetic momenta decrease. The multichannel calculation with perturbative exchanges is shown to yield reasonable magnetic moments while the mass spectrum is close to experiment.
[ { "created": "Tue, 16 Mar 2004 14:31:42 GMT", "version": "v1" } ]
2014-11-17
[ [ "Weda", "J.", "", "University of Utrecht, The Netherlands" ], [ "Tjon", "J. A.", "", "Jefferson Lab, USA" ] ]
The QCD-string model for baryons derived by Simonov and used for the calculation of baryon magnetic moments in a previous paper is extended to include also perturbative gluon and meson exchanges. The mass spectrum of the baryon multiplet is studied. For the meson interaction either the pseudoscalar or pseudovector coupling is used. Predictions are compared with the experimental data. Besides these exchanges the influence of excited quark orbitals on the baryon ground state are considered by performing a multichannel calculation. The nucleon-Delta splitting increases due to the mixing of higher quark states while the baryon magnetic momenta decrease. The multichannel calculation with perturbative exchanges is shown to yield reasonable magnetic moments while the mass spectrum is close to experiment.
hep-ph/9908211
Luis Bento
Luis Bento and Zurab Berezhiani
Classical Nambu-Goldstone fields
11 pages, updated, to appear in PRD
Phys.Rev. D62 (2000) 055003
10.1103/PhysRevD.62.055003
CFNUL/99-02, DFAQ/99/TH/03
hep-ph
null
It is shown that a Nambu-Goldstone (NG) field may be coherently produced by a large number of particles in spite of the fact that the NG bosons do not couple to flavor conserving scalar densities like $\bar{\psi}\psi$. If a flavor oscillation process takes place the phases of the pseudo-scalar or flavor violating densities of different particles do not necessarily cancel each other. The NG boson gets a macroscopic source whenever the total (spontaneously broken) quantum number carried by the source particles suffers a net increase or decrease in time. If the lepton numbers are spontaneously broken such classical NG (majoron) fields may significantly change the neutrino oscillation processes in stars pushing the observational capabilities of neutrino-majoron couplings down to $m_{\nu}/300$ GeV.
[ { "created": "Mon, 2 Aug 1999 00:54:41 GMT", "version": "v1" }, { "created": "Wed, 17 May 2000 12:28:29 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bento", "Luis", "" ], [ "Berezhiani", "Zurab", "" ] ]
It is shown that a Nambu-Goldstone (NG) field may be coherently produced by a large number of particles in spite of the fact that the NG bosons do not couple to flavor conserving scalar densities like $\bar{\psi}\psi$. If a flavor oscillation process takes place the phases of the pseudo-scalar or flavor violating densities of different particles do not necessarily cancel each other. The NG boson gets a macroscopic source whenever the total (spontaneously broken) quantum number carried by the source particles suffers a net increase or decrease in time. If the lepton numbers are spontaneously broken such classical NG (majoron) fields may significantly change the neutrino oscillation processes in stars pushing the observational capabilities of neutrino-majoron couplings down to $m_{\nu}/300$ GeV.
1311.5389
Stefan Floerchinger
Stefan Floerchinger and Christof Wetterich
Isotropization from Color Field Condensate in heavy ion collisions
30 pages, 11 figures, published version
null
10.1007/JHEP03(2014)121
CERN-PH-TH/2013-280
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The expanding fireball shortly after a heavy ion collision may be qualitatively described by a condensate of color fields or gluons which is analogous to Bose-Einstein-condensation for massive bosonic particles. This condensate is a transient non-equilibrium phenomenon and breaks Lorentz-boost symmetry. The dynamics of color field condensates involves collective excitations and is rather different from the perturbative scattering of gluons. In particular, it provides for an efficient mechanism to render the local pressure approximately isotropic after a short time of 0.2 fm/c. We suggest that an isotropic color field condensate may play a central role for a simple description of prethermalization and isotropization in the early stages of the collision.
[ { "created": "Thu, 21 Nov 2013 13:06:29 GMT", "version": "v1" }, { "created": "Wed, 27 Aug 2014 11:34:22 GMT", "version": "v2" } ]
2014-08-28
[ [ "Floerchinger", "Stefan", "" ], [ "Wetterich", "Christof", "" ] ]
The expanding fireball shortly after a heavy ion collision may be qualitatively described by a condensate of color fields or gluons which is analogous to Bose-Einstein-condensation for massive bosonic particles. This condensate is a transient non-equilibrium phenomenon and breaks Lorentz-boost symmetry. The dynamics of color field condensates involves collective excitations and is rather different from the perturbative scattering of gluons. In particular, it provides for an efficient mechanism to render the local pressure approximately isotropic after a short time of 0.2 fm/c. We suggest that an isotropic color field condensate may play a central role for a simple description of prethermalization and isotropization in the early stages of the collision.
1307.7999
Marcin Badziak
Marcin Badziak, Marek Olechowski, Stefan Pokorski
Light staus and enhanced Higgs diphoton rate with non-universal gaugino masses and SO(10) Yukawa unification
28 pages, 8 figures, comments and references added, matches published version
JHEP 10 (2013) 088
10.1007/JHEP10(2013)088
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that substantially enhanced Higgs to diphoton rate induced by light staus with large left-right mixing in MSSM requires at the GUT scale non-universal gaugino masses with bino and/or wino lighter than gluino. The possibility of such enhancement is investigated in MSSM models with arbitrary gaugino masses at the GUT scale with additional restriction of top-bottom-tau Yukawa unification, as predicted by minimal SO(10) GUTs. Many patterns of gaugino masses leading to enhanced Higgs to diphoton rate and the Yukawa unification are identified. Some of these patterns can be accommodated in a well-motivated scenarios such as mirage mediation or SUSY breaking F-terms being a non-singlet of SO(10). Phenomenological implications of a scenario with non-universal gaugino masses generated by a mixture of the singlet F-term and the F-term in a 24-dimensional representation of SU(5) $\subset$ SO(10) are studied in detail. Possible non-universalities of other soft terms generated by such F-terms are discussed. The enhancement of Higgs to diphoton rate up to 30% can be obtained in agreement with all phenomenological constraints, including vacuum metastability bounds. The lightest sbottom and pseudoscalar Higgs are within easy reach of the 14 TeV LHC. The LSP can be either bino-like or wino-like. The thermal relic abundance in the former case may be in agreement with the cosmological data thanks to efficient stau coannihilation.
[ { "created": "Tue, 30 Jul 2013 14:34:58 GMT", "version": "v1" }, { "created": "Thu, 17 Oct 2013 15:15:14 GMT", "version": "v2" } ]
2013-10-18
[ [ "Badziak", "Marcin", "" ], [ "Olechowski", "Marek", "" ], [ "Pokorski", "Stefan", "" ] ]
It is shown that substantially enhanced Higgs to diphoton rate induced by light staus with large left-right mixing in MSSM requires at the GUT scale non-universal gaugino masses with bino and/or wino lighter than gluino. The possibility of such enhancement is investigated in MSSM models with arbitrary gaugino masses at the GUT scale with additional restriction of top-bottom-tau Yukawa unification, as predicted by minimal SO(10) GUTs. Many patterns of gaugino masses leading to enhanced Higgs to diphoton rate and the Yukawa unification are identified. Some of these patterns can be accommodated in a well-motivated scenarios such as mirage mediation or SUSY breaking F-terms being a non-singlet of SO(10). Phenomenological implications of a scenario with non-universal gaugino masses generated by a mixture of the singlet F-term and the F-term in a 24-dimensional representation of SU(5) $\subset$ SO(10) are studied in detail. Possible non-universalities of other soft terms generated by such F-terms are discussed. The enhancement of Higgs to diphoton rate up to 30% can be obtained in agreement with all phenomenological constraints, including vacuum metastability bounds. The lightest sbottom and pseudoscalar Higgs are within easy reach of the 14 TeV LHC. The LSP can be either bino-like or wino-like. The thermal relic abundance in the former case may be in agreement with the cosmological data thanks to efficient stau coannihilation.
1304.3558
Abhishek Iyer M
Abhishek M Iyer and Sudhir K Vempati
Warped Alternatives to Froggatt-Nielsen Models
7 Figures, 34 pages. Minor modifications of the text mostly typos and references added. A couple of typos fixed in the tables. Conclusions unchanged
null
10.1103/PhysRevD.88.016005
null
hep-ph hep-th
http://creativecommons.org/licenses/by/3.0/
We consider Randall-Sundrum set up (RS) to be a theory of flavour, as an alternative to Froggatt-Nielsen models instead of as a solution to the hierarchy problem. We consider a modified RS framework between the Planck scale and the GUT scale. This also alleviates constraints from flavour physics. Fermion masses and mixing angles are fit at the GUT scale. The ranges of the bulk mass parameters are determined using a $\chi^2$ fit taking in to consideration the variation in $\mathcal{O}(1)$ parameters. In the hadronic sector, the heavy top quark requires large bulk mass parameters localising the right handed top quark close to the IR brane. Two cases of neutrino masses are considered (a) Planck scale lepton number violation and (b) Dirac neutrino masses. Contrary to the case of weak scale RS models, both these cases give reasonable fits to the data, with the Planck scale lepton number violation fitting slightly better compared to the Dirac case. In the Supersymmetric version, the fits are not significantly different except for the variation in $\tan\beta$. If the Higgs superfield and the SUSY breaking spurion are localized on the same brane then the structure of the sfermion masses are determined by the profiles of the zero modes of the hypermultiplets in the bulk. Trilinear terms have the same structure as the Yukawa matrices. The resultant squark spectrum is around $\sim 2-3 \text{TeV}$ required by the light Higgs mass to be around 125 GeV and to satisfy the flavour violating constraints.
[ { "created": "Fri, 12 Apr 2013 07:45:21 GMT", "version": "v1" }, { "created": "Tue, 23 Apr 2013 19:19:24 GMT", "version": "v2" } ]
2013-08-09
[ [ "Iyer", "Abhishek M", "" ], [ "Vempati", "Sudhir K", "" ] ]
We consider Randall-Sundrum set up (RS) to be a theory of flavour, as an alternative to Froggatt-Nielsen models instead of as a solution to the hierarchy problem. We consider a modified RS framework between the Planck scale and the GUT scale. This also alleviates constraints from flavour physics. Fermion masses and mixing angles are fit at the GUT scale. The ranges of the bulk mass parameters are determined using a $\chi^2$ fit taking in to consideration the variation in $\mathcal{O}(1)$ parameters. In the hadronic sector, the heavy top quark requires large bulk mass parameters localising the right handed top quark close to the IR brane. Two cases of neutrino masses are considered (a) Planck scale lepton number violation and (b) Dirac neutrino masses. Contrary to the case of weak scale RS models, both these cases give reasonable fits to the data, with the Planck scale lepton number violation fitting slightly better compared to the Dirac case. In the Supersymmetric version, the fits are not significantly different except for the variation in $\tan\beta$. If the Higgs superfield and the SUSY breaking spurion are localized on the same brane then the structure of the sfermion masses are determined by the profiles of the zero modes of the hypermultiplets in the bulk. Trilinear terms have the same structure as the Yukawa matrices. The resultant squark spectrum is around $\sim 2-3 \text{TeV}$ required by the light Higgs mass to be around 125 GeV and to satisfy the flavour violating constraints.
2005.09700
George Savvidy K
Roland Kirschner and George Savvidy
Parton Distribution Functions and Tensor Gluons
12 pages, references added. arXiv admin note: substantial text overlap with arXiv:1310.0856, arXiv:1511.00274
null
null
NRCPS-HE-27-2020
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We further consider a possibility that inside the proton and, more generally, inside the hadrons, there are additional partons - tensor gluons, which can carry a part of the proton momentum. The tensorgluons have zero electric charge, like gluons, but have a larger spin. Inside the proton a nonzero density of the tensorgluons can be generated by the emission of tensorgluons by gluons. The last mechanism is typical for non-Abelian tensor gauge theories. The process of gluon splitting suggests that part of the proton momentum that was carried by neutral partons is shared between vector and tensor gluons. We derive the regularised evolution equations for the parton distribution functions that take into account these new processes. In particular, this will allow to solve numerically the extended DIGLAP equations and to find out the ratio of densities between gluons and tensorgluons.
[ { "created": "Tue, 19 May 2020 18:38:13 GMT", "version": "v1" }, { "created": "Tue, 2 Jun 2020 16:25:59 GMT", "version": "v2" } ]
2020-06-04
[ [ "Kirschner", "Roland", "" ], [ "Savvidy", "George", "" ] ]
We further consider a possibility that inside the proton and, more generally, inside the hadrons, there are additional partons - tensor gluons, which can carry a part of the proton momentum. The tensorgluons have zero electric charge, like gluons, but have a larger spin. Inside the proton a nonzero density of the tensorgluons can be generated by the emission of tensorgluons by gluons. The last mechanism is typical for non-Abelian tensor gauge theories. The process of gluon splitting suggests that part of the proton momentum that was carried by neutral partons is shared between vector and tensor gluons. We derive the regularised evolution equations for the parton distribution functions that take into account these new processes. In particular, this will allow to solve numerically the extended DIGLAP equations and to find out the ratio of densities between gluons and tensorgluons.
2201.03714
Carlos Mu\~noz Camacho
F. Georges, M.N.H. Rashad, A. Stefanko, M. Dlamini, B. Karki, S.F. Ali, P-J. Lin, H-S Ko, N. Israel, D. Adikaram, Z. Ahmed, H. Albataineh, B. Aljawrneh, K. Allada, S. Allison, S. Alsalmi, D. Androic, K. Aniol, J. Annand, H. Atac, T. Averett, C. Ayerbe Gayoso, X. Bai, J. Bane, S. Barcus, K. Bartlett, V. Bellini, R. Beminiwattha, J. Bericic, D. Biswas, E. Brash, D. Bulumulla, J. Campbell, A. Camsonne, M. Carmignotto, J. Castellano, C. Chen, J-P. Chen, T. Chetry, M.E. Christy, E. Cisbani, B. Clary, E. Cohen, N. Compton, J.C. Cornejo, S. Covrig Dusa, B. Crowe, S. Danagoulian, T. Danley, F. De Persio, W. Deconinck, M. Defurne, C. Desnault, D. Di, M. Duer, B. Duran, R. Ent, C. Fanelli, G. Franklin, E. Fuchey, C. Gal, D. Gaskell, T. Gautam, O. Glamazdin, K. Gnanvo, V.M. Gray, C. Gu, T. Hague, G. Hamad, D. Hamilton, K. Hamilton, O. Hansen, F. Hauenstein, W. Henry, D.W. Higinbotham, T. Holmstrom, T. Horn, Y. Huang, G.M. Huber, C. Hyde, H. Ibrahim, C-M. Jen, K. Jin, M. Jones, A. Kabir, C. Keppel, V. Khachatryan, P.M. King, S. Li, W.B. Li, J. Liu, H. Liu, A. Liyanage, J. Magee, S. Malace, J. Mammei, P. Markowitz, E. McClellan, M. Mazouz, F. Meddi, D. Meekins, K. Mesik, R. Michaels, A. Mkrtchyan, R. Montgomery, C. Mu\~noz Camacho, L.S. Myers, P. Nadel-Turonski, S.J. Nazeer, V. Nelyubin, D. Nguyen, N. Nuruzzaman, M. Nycz, O.F. Obretch, L. Ou, C. Palatchi, B. Pandey, S. Park, K. Park, C. Peng, R. Pomatsalyuk, E. Pooser, A.J.R. Puckett, V. Punjabi, B. Quinn, S. Rahman, P.E. Reimer, J. Roche, I. Sapkota, A. Sarty, B. Sawatzky, N.H. Saylor, B. Schmookler, M.H. Shabestari, A. Shahinyan, S. Sirca, G.R. Smith, S. Sooriyaarachchilage, N. Sparveris, R. Spies, T. Su, A. Subedi, V. Sulkosky, A. Sun, L. Thorne, Y. Tian, N. Ton, F. Tortorici, R. Trotta, G.M. Urciuoli, E. Voutier, B. Waidyawansa, Y. Wang, B. Wojtsekhowski, S. Wood, X. Yan, L. Ye, Z. Ye, C. Yero, J. Zhang, Y. Zhao, and P. Zhu
Deeply virtual Compton scattering cross section at high Bjorken $x_B$
null
null
10.1103/PhysRevLett.128.252002
null
hep-ph hep-ex nucl-ex
http://creativecommons.org/licenses/by/4.0/
We report high-precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section at high values of the Bjorken variable $x_B$. DVCS is sensitive to the Generalized Parton Distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton Form Factors (CFFs) of the nucleon as a function of $x_B$, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.
[ { "created": "Tue, 11 Jan 2022 00:31:00 GMT", "version": "v1" } ]
2022-07-13
[ [ "Georges", "F.", "" ], [ "Rashad", "M. N. H.", "" ], [ "Stefanko", "A.", "" ], [ "Dlamini", "M.", "" ], [ "Karki", "B.", "" ], [ "Ali", "S. F.", "" ], [ "Lin", "P-J.", "" ], [ "Ko", "H-S", "" ], [ "Israel", "N.", "" ], [ "Adikaram", "D.", "" ], [ "Ahmed", "Z.", "" ], [ "Albataineh", "H.", "" ], [ "Aljawrneh", "B.", "" ], [ "Allada", "K.", "" ], [ "Allison", "S.", "" ], [ "Alsalmi", "S.", "" ], [ "Androic", "D.", "" ], [ "Aniol", "K.", "" ], [ "Annand", "J.", "" ], [ "Atac", "H.", "" ], [ "Averett", "T.", "" ], [ "Gayoso", "C. Ayerbe", "" ], [ "Bai", "X.", "" ], [ "Bane", "J.", "" ], [ "Barcus", "S.", "" ], [ "Bartlett", "K.", "" ], [ "Bellini", "V.", "" ], [ "Beminiwattha", "R.", "" ], [ "Bericic", "J.", "" ], [ "Biswas", "D.", "" ], [ "Brash", "E.", "" ], [ "Bulumulla", "D.", "" ], [ "Campbell", "J.", "" ], [ "Camsonne", "A.", "" ], [ "Carmignotto", "M.", "" ], [ "Castellano", "J.", "" ], [ "Chen", "C.", "" ], [ "Chen", "J-P.", "" ], [ "Chetry", "T.", "" ], [ "Christy", "M. E.", "" ], [ "Cisbani", "E.", "" ], [ "Clary", "B.", "" ], [ "Cohen", "E.", "" ], [ "Compton", "N.", "" ], [ "Cornejo", "J. C.", "" ], [ "Dusa", "S. Covrig", "" ], [ "Crowe", "B.", "" ], [ "Danagoulian", "S.", "" ], [ "Danley", "T.", "" ], [ "De Persio", "F.", "" ], [ "Deconinck", "W.", "" ], [ "Defurne", "M.", "" ], [ "Desnault", "C.", "" ], [ "Di", "D.", "" ], [ "Duer", "M.", "" ], [ "Duran", "B.", "" ], [ "Ent", "R.", "" ], [ "Fanelli", "C.", "" ], [ "Franklin", "G.", "" ], [ "Fuchey", "E.", "" ], [ "Gal", "C.", "" ], [ "Gaskell", "D.", "" ], [ "Gautam", "T.", "" ], [ "Glamazdin", "O.", "" ], [ "Gnanvo", "K.", "" ], [ "Gray", "V. M.", "" ], [ "Gu", "C.", "" ], [ "Hague", "T.", "" ], [ "Hamad", "G.", "" ], [ "Hamilton", "D.", "" ], [ "Hamilton", "K.", "" ], [ "Hansen", "O.", "" ], [ "Hauenstein", "F.", "" ], [ "Henry", "W.", "" ], [ "Higinbotham", "D. W.", "" ], [ "Holmstrom", "T.", "" ], [ "Horn", "T.", "" ], [ "Huang", "Y.", "" ], [ "Huber", "G. M.", "" ], [ "Hyde", "C.", "" ], [ "Ibrahim", "H.", "" ], [ "Jen", "C-M.", "" ], [ "Jin", "K.", "" ], [ "Jones", "M.", "" ], [ "Kabir", "A.", "" ], [ "Keppel", "C.", "" ], [ "Khachatryan", "V.", "" ], [ "King", "P. M.", "" ], [ "Li", "S.", "" ], [ "Li", "W. B.", "" ], [ "Liu", "J.", "" ], [ "Liu", "H.", "" ], [ "Liyanage", "A.", "" ], [ "Magee", "J.", "" ], [ "Malace", "S.", "" ], [ "Mammei", "J.", "" ], [ "Markowitz", "P.", "" ], [ "McClellan", "E.", "" ], [ "Mazouz", "M.", "" ], [ "Meddi", "F.", "" ], [ "Meekins", "D.", "" ], [ "Mesik", "K.", "" ], [ "Michaels", "R.", "" ], [ "Mkrtchyan", "A.", "" ], [ "Montgomery", "R.", "" ], [ "Camacho", "C. Muñoz", "" ], [ "Myers", "L. S.", "" ], [ "Nadel-Turonski", "P.", "" ], [ "Nazeer", "S. J.", "" ], [ "Nelyubin", "V.", "" ], [ "Nguyen", "D.", "" ], [ "Nuruzzaman", "N.", "" ], [ "Nycz", "M.", "" ], [ "Obretch", "O. F.", "" ], [ "Ou", "L.", "" ], [ "Palatchi", "C.", "" ], [ "Pandey", "B.", "" ], [ "Park", "S.", "" ], [ "Park", "K.", "" ], [ "Peng", "C.", "" ], [ "Pomatsalyuk", "R.", "" ], [ "Pooser", "E.", "" ], [ "Puckett", "A. J. R.", "" ], [ "Punjabi", "V.", "" ], [ "Quinn", "B.", "" ], [ "Rahman", "S.", "" ], [ "Reimer", "P. E.", "" ], [ "Roche", "J.", "" ], [ "Sapkota", "I.", "" ], [ "Sarty", "A.", "" ], [ "Sawatzky", "B.", "" ], [ "Saylor", "N. H.", "" ], [ "Schmookler", "B.", "" ], [ "Shabestari", "M. H.", "" ], [ "Shahinyan", "A.", "" ], [ "Sirca", "S.", "" ], [ "Smith", "G. R.", "" ], [ "Sooriyaarachchilage", "S.", "" ], [ "Sparveris", "N.", "" ], [ "Spies", "R.", "" ], [ "Su", "T.", "" ], [ "Subedi", "A.", "" ], [ "Sulkosky", "V.", "" ], [ "Sun", "A.", "" ], [ "Thorne", "L.", "" ], [ "Tian", "Y.", "" ], [ "Ton", "N.", "" ], [ "Tortorici", "F.", "" ], [ "Trotta", "R.", "" ], [ "Urciuoli", "G. M.", "" ], [ "Voutier", "E.", "" ], [ "Waidyawansa", "B.", "" ], [ "Wang", "Y.", "" ], [ "Wojtsekhowski", "B.", "" ], [ "Wood", "S.", "" ], [ "Yan", "X.", "" ], [ "Ye", "L.", "" ], [ "Ye", "Z.", "" ], [ "Yero", "C.", "" ], [ "Zhang", "J.", "" ], [ "Zhao", "Y.", "" ], [ "Zhu", "P.", "" ] ]
We report high-precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section at high values of the Bjorken variable $x_B$. DVCS is sensitive to the Generalized Parton Distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton Form Factors (CFFs) of the nucleon as a function of $x_B$, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.
hep-ph/0310054
Luis Anchordoqui
Luis Anchordoqui and Haim Goldberg
Footprints of Super-GZK Cosmic Rays in the Pilliga State Forest
7 pages revtex, 7 figures
Phys.Lett. B583 (2004) 213-221
10.1016/j.physletb.2003.12.072
NUB-3241-TH-03
hep-ph astro-ph gr-qc hep-ex hep-th
null
High energy cosmic ray data collected by the SUGAR Collaboration in the Pilliga State Forest have been re-analyzed using up-to-date shower simulations. Complete, inclined angle, Monte Carlo simulations reveal 2 events with energies in excess of $7\times 10^{19}$ eV at 95% CL, independent of the choice of hadronic interaction model and of chemical composition of the primary. An additional 3 events, with mean energy $\agt 7\times 10^{19}$ eV, were also re-analyzed in the same manner. A lower bound on the flux at the high end of the spectrum, as observed in the Southern sky, is presented on the basis of our analysis.
[ { "created": "Mon, 6 Oct 2003 15:17:35 GMT", "version": "v1" } ]
2009-11-10
[ [ "Anchordoqui", "Luis", "" ], [ "Goldberg", "Haim", "" ] ]
High energy cosmic ray data collected by the SUGAR Collaboration in the Pilliga State Forest have been re-analyzed using up-to-date shower simulations. Complete, inclined angle, Monte Carlo simulations reveal 2 events with energies in excess of $7\times 10^{19}$ eV at 95% CL, independent of the choice of hadronic interaction model and of chemical composition of the primary. An additional 3 events, with mean energy $\agt 7\times 10^{19}$ eV, were also re-analyzed in the same manner. A lower bound on the flux at the high end of the spectrum, as observed in the Southern sky, is presented on the basis of our analysis.
0903.2793
Francesca Borzumati
Francesca Borzumati and Toshifumi Yamashita
Minimal supersymmetric SU(5) model with nonrenormalizable operators: Seesaw mechanism and violation of flavour and CP
108 pages, 4 figs. v4: Minor improvements. Published version. The RGEs of App E can be found in a very explicit form at http://www.tuhep.phys.tohoku.ac.jp/~francescaB/rges.html
Prog.Theor.Phys.124:761-868,2010
10.1143/PTP.124.761
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flavour and CP violations that the neutrino-seesaw couplings of types I, II, and III induce radiatively in the soft massive parameters of the minimal supersymmetric SU(5) model, made realistic by nonrenormalizable operators, are analyzed. Effective couplings are used to parametrize the couplings of renormalizable operators and of the corrections that nonrenormalizable ones provide at the tree level. It is found that for a limited, but sufficient accuracy in the calculations of such violations, it is possible to extend the picture of effective couplings to the quantum level, all the way to the cutoff scale. The arbitrariness introduced by nonrenormalizable operators is analyzed in detail. It is shown that it can be drastically reduced in the Yukawa sector if the effective Yukawa couplings involving colored triplet Higgs bosons are tuned to suppress the decay rate of the proton. In the supersymmetry-breaking sector, the usual requirement of independence of flavour and field type for the mechanism of mediation of supersymmetry breaking is not sufficient to forbid arbitrary flavour and CP violations at the tree level. Special conditions to be added to this requirement, under which such violations can be avoided, are identified. Depending on how and whether these conditions are implemented, different phenomenological scenarios emerge. Flavour and CP violations of soft massive parameters induced by neutrino-seesaw couplings are discussed explicitly for the simplest scenario, in which no such violations are present at the tree level. Guidelines for studying them in other, less simple scenarios are given. Lists of all renormalization group equations needed for their calculations are provided for each of the three types of seesaw mechanism, at all energies between the TeV scale and Planck scale.
[ { "created": "Mon, 16 Mar 2009 16:37:06 GMT", "version": "v1" }, { "created": "Fri, 16 Oct 2009 05:45:13 GMT", "version": "v2" }, { "created": "Wed, 19 May 2010 03:08:34 GMT", "version": "v3" }, { "created": "Wed, 24 Nov 2010 07:02:59 GMT", "version": "v4" } ]
2011-05-12
[ [ "Borzumati", "Francesca", "" ], [ "Yamashita", "Toshifumi", "" ] ]
Flavour and CP violations that the neutrino-seesaw couplings of types I, II, and III induce radiatively in the soft massive parameters of the minimal supersymmetric SU(5) model, made realistic by nonrenormalizable operators, are analyzed. Effective couplings are used to parametrize the couplings of renormalizable operators and of the corrections that nonrenormalizable ones provide at the tree level. It is found that for a limited, but sufficient accuracy in the calculations of such violations, it is possible to extend the picture of effective couplings to the quantum level, all the way to the cutoff scale. The arbitrariness introduced by nonrenormalizable operators is analyzed in detail. It is shown that it can be drastically reduced in the Yukawa sector if the effective Yukawa couplings involving colored triplet Higgs bosons are tuned to suppress the decay rate of the proton. In the supersymmetry-breaking sector, the usual requirement of independence of flavour and field type for the mechanism of mediation of supersymmetry breaking is not sufficient to forbid arbitrary flavour and CP violations at the tree level. Special conditions to be added to this requirement, under which such violations can be avoided, are identified. Depending on how and whether these conditions are implemented, different phenomenological scenarios emerge. Flavour and CP violations of soft massive parameters induced by neutrino-seesaw couplings are discussed explicitly for the simplest scenario, in which no such violations are present at the tree level. Guidelines for studying them in other, less simple scenarios are given. Lists of all renormalization group equations needed for their calculations are provided for each of the three types of seesaw mechanism, at all energies between the TeV scale and Planck scale.
hep-ph/0501101
Tianjun Li
Junhai Kang, Tianjun Li
Light Sterile Neutrinos in the Supersymmetric U(1)' Models and Axion Models
RevTex4, 19 pages, References added
Phys.Rev.D71:095011,2005
10.1103/PhysRevD.71.095011
null
hep-ph
null
We propose the minimal supersymmetric sterile neutrino model (MSSNM) where the sterile neutrino masses are about 1 eV, while the active neutrino masses and the mixings among the active and sterile neutrinos are generated during late time phase transition. All the current experimental neutrino data include the LSND can be explained simultaneously, and the constraints on the sterile neutrinos from the big bang nucleosynthesis and large scale structure can be evaded. To realize the MSSNM naturally, we consider the supersymmetric intermediate-scale U(1)' model, the low energy U(1)' model with a secluded U(1)'-breaking sector, and the DFSZ and KSVZ axion models. In these models, the $\mu$ problem can be solved elegantly, and the 1 eV sterile neutrino masses can be generated via high-dimensional operators. For the low energy U(1)' model with a secluded U(1)'-breaking sector, we also present a scenario in which the masses and mixings for the active and sterile neutrinos are all generated during late time phase transition.
[ { "created": "Thu, 13 Jan 2005 04:27:08 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2005 21:05:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kang", "Junhai", "" ], [ "Li", "Tianjun", "" ] ]
We propose the minimal supersymmetric sterile neutrino model (MSSNM) where the sterile neutrino masses are about 1 eV, while the active neutrino masses and the mixings among the active and sterile neutrinos are generated during late time phase transition. All the current experimental neutrino data include the LSND can be explained simultaneously, and the constraints on the sterile neutrinos from the big bang nucleosynthesis and large scale structure can be evaded. To realize the MSSNM naturally, we consider the supersymmetric intermediate-scale U(1)' model, the low energy U(1)' model with a secluded U(1)'-breaking sector, and the DFSZ and KSVZ axion models. In these models, the $\mu$ problem can be solved elegantly, and the 1 eV sterile neutrino masses can be generated via high-dimensional operators. For the low energy U(1)' model with a secluded U(1)'-breaking sector, we also present a scenario in which the masses and mixings for the active and sterile neutrinos are all generated during late time phase transition.
2110.01540
Shahin Iqbal
Yu Fu, Jacopo Ghiglieri, Shahin Iqbal, Aleksi Kurkela
Thermalization of non-abelian gauge theories at next-to-leading order
9 Pages and two figures
null
10.1103/PhysRevD.105.054031
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We provide the first next-to-leading-order (NLO) weak-coupling description of the thermalization process of far-from-equilibrium systems in non-abelian gauge theory. We study isotropic systems starting from either over- or under-occupied initial conditions and follow their time evolution towards thermal equilibrium by numerically solving the QCD effective kinetic theory at NLO accuracy. We find that the NLO corrections remain well under control for a wide range of couplings and that the overall effect of NLO corrections is to reduce the time needed to reach thermal equilibrium in the systems considered.
[ { "created": "Mon, 4 Oct 2021 16:20:20 GMT", "version": "v1" } ]
2022-04-13
[ [ "Fu", "Yu", "" ], [ "Ghiglieri", "Jacopo", "" ], [ "Iqbal", "Shahin", "" ], [ "Kurkela", "Aleksi", "" ] ]
We provide the first next-to-leading-order (NLO) weak-coupling description of the thermalization process of far-from-equilibrium systems in non-abelian gauge theory. We study isotropic systems starting from either over- or under-occupied initial conditions and follow their time evolution towards thermal equilibrium by numerically solving the QCD effective kinetic theory at NLO accuracy. We find that the NLO corrections remain well under control for a wide range of couplings and that the overall effect of NLO corrections is to reduce the time needed to reach thermal equilibrium in the systems considered.
1410.6998
Gergely Mark\'o
Gergely Mark\'o, Urko Reinosa and Zsolt Sz\'ep
Bose-Einstein condensation and Silver Blaze property from the two-loop $\Phi$-derivable approximation
22 pages, 6 figures, uses RevTeX 4-1
null
10.1103/PhysRevD.90.125021
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend our previous investigation of the two-loop $\Phi$-derivable approximation to finite chemical potential $\mu$ and discuss Bose-Einstein condensation (BEC) in the case of a charged scalar field with $O(2)$ symmetry. We show that the approximation is renormalizable by means of counterterms which are independent of both the temperature and the chemical potential. We point out the presence of an additional skew contribution to the propagator as compared to the $\mu=0$ case, which comes with its own gap equation (except at Hartree level). We solve this equation together with the field equation, and the usual longitudinal and transversal gap equations to find that the transition is second order, in agreement with recent lattice results to which we compare. We also discuss a general criterion an approximation should obey for the so-called Silver Blaze property to hold, and we show that any $\Phi$-derivable approximation at finite temperature and density obeys this criterion if one chooses a UV regularization that does not cut off the Matsubara sums.
[ { "created": "Sun, 26 Oct 2014 08:11:01 GMT", "version": "v1" } ]
2015-06-23
[ [ "Markó", "Gergely", "" ], [ "Reinosa", "Urko", "" ], [ "Szép", "Zsolt", "" ] ]
We extend our previous investigation of the two-loop $\Phi$-derivable approximation to finite chemical potential $\mu$ and discuss Bose-Einstein condensation (BEC) in the case of a charged scalar field with $O(2)$ symmetry. We show that the approximation is renormalizable by means of counterterms which are independent of both the temperature and the chemical potential. We point out the presence of an additional skew contribution to the propagator as compared to the $\mu=0$ case, which comes with its own gap equation (except at Hartree level). We solve this equation together with the field equation, and the usual longitudinal and transversal gap equations to find that the transition is second order, in agreement with recent lattice results to which we compare. We also discuss a general criterion an approximation should obey for the so-called Silver Blaze property to hold, and we show that any $\Phi$-derivable approximation at finite temperature and density obeys this criterion if one chooses a UV regularization that does not cut off the Matsubara sums.
2403.18630
Zhen-hua Zhao
Zhen-hua Zhao, Jing Zhang, Xiang-Yi Wu
Flavored leptogenesis from a sudden mass gain of right-handed neutrinos
16 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we would like to point out that in the scenario that the right-handed neutrinos suddenly gain some masses much larger than the temperature of the Universe at that time so that the washout effects for the generated lepton asymmetry can be safely neglected, the flavored leptogenesis (which crucially rely on the flavor non-universality of the washout effects) cannot work in the usual way any more. For this problem, we put forward that the flavor non-universality of the conversion efficiencies from the lepton asymmetry to the baryon asymmetry via the sphaleron processes may play a crucial role. And we will study if the requisite baryon asymmetry can be successfully reproduced from such a mechanism in the scenarios that the right-handed neutrino masses are hierarchical and nearly degenerate, respectively. A detailed study shows that this mechanism can be viable in both these two scenarios.
[ { "created": "Wed, 27 Mar 2024 14:37:46 GMT", "version": "v1" } ]
2024-03-28
[ [ "Zhao", "Zhen-hua", "" ], [ "Zhang", "Jing", "" ], [ "Wu", "Xiang-Yi", "" ] ]
In this paper, we would like to point out that in the scenario that the right-handed neutrinos suddenly gain some masses much larger than the temperature of the Universe at that time so that the washout effects for the generated lepton asymmetry can be safely neglected, the flavored leptogenesis (which crucially rely on the flavor non-universality of the washout effects) cannot work in the usual way any more. For this problem, we put forward that the flavor non-universality of the conversion efficiencies from the lepton asymmetry to the baryon asymmetry via the sphaleron processes may play a crucial role. And we will study if the requisite baryon asymmetry can be successfully reproduced from such a mechanism in the scenarios that the right-handed neutrino masses are hierarchical and nearly degenerate, respectively. A detailed study shows that this mechanism can be viable in both these two scenarios.
1811.00486
Seddigheh Tizchang
Seddigheh Tizchang, Rohoollah Mohammadi, She-Sheng Xue
Probing Lorentz violation effects via a laser beam interacting with a high-energy charged lepton beam
11 pages, 3 figures and 2 tables
Eur. Phys. J. C (2019) 79: 224
10.1140/epjc/s10052-019-6716-5
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, the conversion of linear polarization of a laser beam to circular one through its forward scattering by a TeV order charged lepton beam in the presence of Lorentz violation correction is explored. We calculate the ratio of circular polarization to linear one (Faraday Conversion phase $\Delta\phi_{\rm{FC}}$) of the laser beam interacting with either electron or the muon beam in the framework of the quantum Boltzmann equation. Regarding the experimentally available sensitivity to the Faraday conversion $\Delta\phi_{\rm{FC}}\simeq 10^{-3}-10^{-2}$, we show that the scattering of a linearly polarized laser beam with energy $k_0\sim 0.1$ eV and an electron/muon beam with flux $\bar{\epsilon}_{e,\mu}\sim 10^{10}/10^{12}$ TeV cm$^{-2}$ s$^{-1}$ places an upper bound on the combination of lepton sector Lorentz violation coefficients $c_{\mu\nu}$ components $(c_{TT}+1.4~c_{(TZ)}+0.25(c_{XX}+c_{YY}+2~c_{ZZ}))$. The obtained bound on the combination for the electron beam is at the $4.35\times 10^{-15}$ level and for the muon beam at the $3.9\times 10^{-13}$ level. It should be mentioned that the laser and charged lepton beams considered here to reach the experimentally measurable $\Delta\phi_{\rm{FC}}$ are currently available or will be accessible in the near future. This study provides a valuable supplementary to other theoretical and experimental frameworks for measuring and constraining Lorentz violation coefficients.
[ { "created": "Thu, 1 Nov 2018 16:30:05 GMT", "version": "v1" }, { "created": "Mon, 18 Mar 2019 18:56:27 GMT", "version": "v2" } ]
2019-03-20
[ [ "Tizchang", "Seddigheh", "" ], [ "Mohammadi", "Rohoollah", "" ], [ "Xue", "She-Sheng", "" ] ]
In this work, the conversion of linear polarization of a laser beam to circular one through its forward scattering by a TeV order charged lepton beam in the presence of Lorentz violation correction is explored. We calculate the ratio of circular polarization to linear one (Faraday Conversion phase $\Delta\phi_{\rm{FC}}$) of the laser beam interacting with either electron or the muon beam in the framework of the quantum Boltzmann equation. Regarding the experimentally available sensitivity to the Faraday conversion $\Delta\phi_{\rm{FC}}\simeq 10^{-3}-10^{-2}$, we show that the scattering of a linearly polarized laser beam with energy $k_0\sim 0.1$ eV and an electron/muon beam with flux $\bar{\epsilon}_{e,\mu}\sim 10^{10}/10^{12}$ TeV cm$^{-2}$ s$^{-1}$ places an upper bound on the combination of lepton sector Lorentz violation coefficients $c_{\mu\nu}$ components $(c_{TT}+1.4~c_{(TZ)}+0.25(c_{XX}+c_{YY}+2~c_{ZZ}))$. The obtained bound on the combination for the electron beam is at the $4.35\times 10^{-15}$ level and for the muon beam at the $3.9\times 10^{-13}$ level. It should be mentioned that the laser and charged lepton beams considered here to reach the experimentally measurable $\Delta\phi_{\rm{FC}}$ are currently available or will be accessible in the near future. This study provides a valuable supplementary to other theoretical and experimental frameworks for measuring and constraining Lorentz violation coefficients.
1211.5061
Umit Kaya
U. Kaya, S. Sultansoy, G. Unel
Probing small x(g) region with the LHeC based gamma-p colliders
7 pages, 18 figures, 5 tables
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Potential of the LHeC for probing small x(g) region via c\bar{c} and b\bar{b} production have been investigated. Obtained results clearly show the advantage of gamma-p collider option. Measurement of x(g) down to 3\times10^{-6} seems to be reachable which is two order smaller than HERA coverage.
[ { "created": "Wed, 21 Nov 2012 15:37:19 GMT", "version": "v1" }, { "created": "Tue, 16 Apr 2013 16:56:27 GMT", "version": "v2" }, { "created": "Mon, 17 Feb 2014 14:11:38 GMT", "version": "v3" } ]
2014-02-18
[ [ "Kaya", "U.", "" ], [ "Sultansoy", "S.", "" ], [ "Unel", "G.", "" ] ]
Potential of the LHeC for probing small x(g) region via c\bar{c} and b\bar{b} production have been investigated. Obtained results clearly show the advantage of gamma-p collider option. Measurement of x(g) down to 3\times10^{-6} seems to be reachable which is two order smaller than HERA coverage.
hep-ph/0509201
Neal Weiner
Neal Weiner (CCPP, NYU), Kathryn Zurek (INT, UW)
New Matter Effects and BBN Constraints for Mass Varying Neutrinos
6 pages. References added, minor modifications
Phys.Rev. D74 (2006) 023517
10.1103/PhysRevD.74.023517
INT-PUB 05-21
hep-ph
null
The presence of light (m_a ~ 10^-6 ev) scalar fields in the early universe can modify the cosmology of neutrinos considerably by allowing their masses to vary on cosmological times. In this paper, we consider the effect of Planck-suppressed couplings of this scalar to electrons and show that such couplings can easily make new sterile states thermally inaccessible in the early universe, preserving the successes of big bang nucleosynthesis predictions. We consider the circumstances under which these effects give the proper initial conditions for recently considered models of neutrino dark energy, and consider limits from tests of the equivalence principle. The parameters which satisfy cosmological constraints naturally give rise to interesting signals in terrestrial neutrino oscillation experiments.
[ { "created": "Tue, 20 Sep 2005 19:18:02 GMT", "version": "v1" }, { "created": "Fri, 27 Jan 2006 20:48:13 GMT", "version": "v2" } ]
2009-11-11
[ [ "Weiner", "Neal", "", "CCPP, NYU" ], [ "Zurek", "Kathryn", "", "INT, UW" ] ]
The presence of light (m_a ~ 10^-6 ev) scalar fields in the early universe can modify the cosmology of neutrinos considerably by allowing their masses to vary on cosmological times. In this paper, we consider the effect of Planck-suppressed couplings of this scalar to electrons and show that such couplings can easily make new sterile states thermally inaccessible in the early universe, preserving the successes of big bang nucleosynthesis predictions. We consider the circumstances under which these effects give the proper initial conditions for recently considered models of neutrino dark energy, and consider limits from tests of the equivalence principle. The parameters which satisfy cosmological constraints naturally give rise to interesting signals in terrestrial neutrino oscillation experiments.
hep-ph/0102196
Nir Polonsky
Nir Polonsky (MIT)
The scale of supersymmetry breaking as a free parameter
9 pages, 1 figure (included). Requires espcrc2.sty (included). Talk given at the 30 Years of Supersymmetry workshop, Oct. 2000
Nucl.Phys.Proc.Suppl.101:357-365,2001
10.1016/S0920-5632(01)01521-3
MIT-CTP-3085
hep-ph
null
While supersymmetric extensions of the Standard Model can be fully described in terms of explicitly broken global supersymmetry, this description is only effective. Once related to spontaneous breaking in a more fundamental theory, the effective parameters translate to functions of two distinct scales, the scale of spontaneous supersymmetry breaking and the scale of its mediation to the standard-model fields. The scale dependence will be written explicitly and the full spectrum of supersymmetry breaking operators which emerges will be explored. It will be shown that, contrary to common lore, scale-dependent operators can play an important role in determining the phenomenology. For example, theories with low-energy supersymmetry breaking, such as gauge mediation, may correspond to a scalar potential which is quite different than in theories with high-energy supersymmetry breaking, such as gravity mediation. As a concrete example, the Higgs mass prediction will be discussed in some detail and its upper bound will be shown to be sensitive to the supersymmetry breaking scale.
[ { "created": "Thu, 15 Feb 2001 18:38:58 GMT", "version": "v1" } ]
2008-11-26
[ [ "Polonsky", "Nir", "", "MIT" ] ]
While supersymmetric extensions of the Standard Model can be fully described in terms of explicitly broken global supersymmetry, this description is only effective. Once related to spontaneous breaking in a more fundamental theory, the effective parameters translate to functions of two distinct scales, the scale of spontaneous supersymmetry breaking and the scale of its mediation to the standard-model fields. The scale dependence will be written explicitly and the full spectrum of supersymmetry breaking operators which emerges will be explored. It will be shown that, contrary to common lore, scale-dependent operators can play an important role in determining the phenomenology. For example, theories with low-energy supersymmetry breaking, such as gauge mediation, may correspond to a scalar potential which is quite different than in theories with high-energy supersymmetry breaking, such as gravity mediation. As a concrete example, the Higgs mass prediction will be discussed in some detail and its upper bound will be shown to be sensitive to the supersymmetry breaking scale.
1112.5268
Yonit Hochberg
Yonit Hochberg and Yosef Nir
Relating direct CP violation in D decays and the forward-backward asymmetry in $t\bar t$ production
4 pages. v3: A calculation of the contribution to epsilon^prime is presented; Conclusions unchanged
null
10.1103/PhysRevLett.108.261601
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CDF and LHCb experiments have recently provided two intriguing hints for new physics: a large forward-backward asymmetry in $t\bar t$ production, and a direct CP asymmetry in D decays of order a percent. In both cases, flavor non-universal interactions are required in the up sector, raising the possibility that the two effects come from one and the same new physics source. We show that a minimal model, with an extra scalar doublet, previously suggested to explain the top data, gives -- without any modifications or additions -- a contribution to CP violation in charm decays that is of the right size.
[ { "created": "Thu, 22 Dec 2011 10:44:48 GMT", "version": "v1" }, { "created": "Thu, 29 Dec 2011 13:33:10 GMT", "version": "v2" }, { "created": "Thu, 23 Feb 2012 09:46:34 GMT", "version": "v3" } ]
2013-05-30
[ [ "Hochberg", "Yonit", "" ], [ "Nir", "Yosef", "" ] ]
The CDF and LHCb experiments have recently provided two intriguing hints for new physics: a large forward-backward asymmetry in $t\bar t$ production, and a direct CP asymmetry in D decays of order a percent. In both cases, flavor non-universal interactions are required in the up sector, raising the possibility that the two effects come from one and the same new physics source. We show that a minimal model, with an extra scalar doublet, previously suggested to explain the top data, gives -- without any modifications or additions -- a contribution to CP violation in charm decays that is of the right size.
hep-ph/0210020
Sobkow Wieslaw
Wieslaw Sobkow (University of Wroclaw, Poland)
Right-handed Neutrinos in Low-Energy Neutrino-Electron Scattering
REVTeX, 9 pages, 5 eps figures; published in Phys. Lett. B 555, 215-226 (2003)
Phys.Lett. B555 (2003) 215-226
10.1016/S0370-2693(03)00050-9
null
hep-ph
null
In this paper a scenario admitting the participation of the exotic scalar coupling of the right-handed neutrinos in addition to the standard vector and axial couplings of the left-handed neutrinos in the weak interactions is considered. The research is based on the low-energy $(\nu_{\mu} e^{-})$ and $(\nu_{e} e^{-})$ scattering processes. The main goal is to show how the presence of the right-handed neutrinos in the above processes changes the laboratory differential cross section in relation to the Standard Model prediction. Both processes are studied at the level of the four-fermion point interaction. Neutrinos are assumed to be polarized Dirac fermions and to be massive. In the laboratory differential cross section, the new interference term between the standard vector coupling of the left-handed neutrinos and exotic scalar coupling of the right-handed neutrinos appears which does not vanish in the limit of massless neutrino. This additional contribution, including information about the transverse components of neutrino polarization, generates the azimuthal asymmetry in the angular distribution of the recoil electrons. This regularity would be a signature of the participation of the right-handed neutrinos in the neutrino-electron scattering. The future low-energy high-precision neutrino-electron scattering experiments using the strong and polarized artificial neutrino source would allow to search for the exotic effects coming from the R-handed neutrinos.
[ { "created": "Tue, 1 Oct 2002 15:29:26 GMT", "version": "v1" }, { "created": "Fri, 28 Feb 2003 18:24:41 GMT", "version": "v2" } ]
2009-11-07
[ [ "Sobkow", "Wieslaw", "", "University of Wroclaw, Poland" ] ]
In this paper a scenario admitting the participation of the exotic scalar coupling of the right-handed neutrinos in addition to the standard vector and axial couplings of the left-handed neutrinos in the weak interactions is considered. The research is based on the low-energy $(\nu_{\mu} e^{-})$ and $(\nu_{e} e^{-})$ scattering processes. The main goal is to show how the presence of the right-handed neutrinos in the above processes changes the laboratory differential cross section in relation to the Standard Model prediction. Both processes are studied at the level of the four-fermion point interaction. Neutrinos are assumed to be polarized Dirac fermions and to be massive. In the laboratory differential cross section, the new interference term between the standard vector coupling of the left-handed neutrinos and exotic scalar coupling of the right-handed neutrinos appears which does not vanish in the limit of massless neutrino. This additional contribution, including information about the transverse components of neutrino polarization, generates the azimuthal asymmetry in the angular distribution of the recoil electrons. This regularity would be a signature of the participation of the right-handed neutrinos in the neutrino-electron scattering. The future low-energy high-precision neutrino-electron scattering experiments using the strong and polarized artificial neutrino source would allow to search for the exotic effects coming from the R-handed neutrinos.
hep-ph/0308233
Davison E. Soper
Davison E. Soper
Partons and Jets at the LHC
Talk at the conference QCD2002 at IIT Kanpur, India, November 2002. Ten pages with 12 figures
Pramana61:793-802,2003
10.1007/BF02704448
null
hep-ph
null
I review some issues related to short distance QCD and its relation to the experimental program of the Large Hadron Collider (LHC) now under construction in Geneva.
[ { "created": "Fri, 22 Aug 2003 20:03:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Soper", "Davison E.", "" ] ]
I review some issues related to short distance QCD and its relation to the experimental program of the Large Hadron Collider (LHC) now under construction in Geneva.
hep-ph/9504425
James F. Amundson
James F. Amundson
Comparison of potential models through HQET
19 pages, LaTeX with epsf.sty. Figures included through uufiles. Compressed Postscript available at ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-859.ps.Z or http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-859.ps.Z
Phys.Rev.D52:2926-2934,1995
10.1103/PhysRevD.52.2926
MAD/PH/859
hep-ph
null
I calculate heavy-light decay constants in a nonrelativistic potential model. The resulting estimate of heavy quark symmetry breaking conflicts with similar estimates from lattice QCD. I show that a semirelativistic potential model eliminates the conflict. Using the results of heavy quark effective theory allows me to identify and compensate for shortcomings in the model calculations in addition to isolating the source of the differences in the two models. The results lead to a rule as to where the nonrelativistic quark model gives misleading predictions.
[ { "created": "Fri, 28 Apr 1995 21:40:57 GMT", "version": "v1" } ]
2011-07-19
[ [ "Amundson", "James F.", "" ] ]
I calculate heavy-light decay constants in a nonrelativistic potential model. The resulting estimate of heavy quark symmetry breaking conflicts with similar estimates from lattice QCD. I show that a semirelativistic potential model eliminates the conflict. Using the results of heavy quark effective theory allows me to identify and compensate for shortcomings in the model calculations in addition to isolating the source of the differences in the two models. The results lead to a rule as to where the nonrelativistic quark model gives misleading predictions.
hep-ph/9802405
Marco Fabbrichesi
S. Bertolini, J.O. Eeg and M. Fabbrichesi
Estimating epsilon'/epsilon. A Review
42 pages, 13 figures. To appear in Reviews of Modern Physics
Rev.Mod.Phys.72:65-93,2000
10.1103/RevModPhys.72.65
SISSA 19/98/EP
hep-ph
null
The real part of epsilon'/epsilon measures direct CP violation in the decays of the neutral kaons in two pions. It is a fundamental quantity which has justly attracted a great deal of theoretical as well as experimental work. Its determination may answer the question of whether CP violation is present only in the mass matrix of neutral kaons (the superweak scenario) or also at work directly in the decays. After a brief historical summary, we discuss the present and expected experimental sensitivities. In the light of these, we come to the problem of estimating epsilon'/epsilon in the standard model. We review the present (circa 1998) status of the theoretical predictions of epsilon'/epsilon. The short-distance part of the computation is now known to the next-to-leading order in QCD and QED and therefore well under control. On the other hand, the evaluation of the hadronic matrix element of the relevant operators is where most of the theoretical uncertainty still resides. We analyze the results of the currently most developed calculations. The values of the B_i parameters in the various approaches are discussed, together with the allowed range of the relevant combination of the Cabibbo-Kobayashi-Maskawa entries Im V_{td}V^*_{ts}. We conclude by summarizing and comparing all up-to-date predictions of epsilon'/epsilon. Because of the intrinsic uncertainties of the long-distance computations, values ranging from 10^{-4} to a few times 10^{-3} can be accounted for in the standard model. Since this range covers most of the present experimental uncertainty, it is unlikely that new physics effects can be disentangled from the standard model prediction. For updates on the review and additional material see http://www.he.sissa.it/review/.
[ { "created": "Tue, 24 Feb 1998 11:40:14 GMT", "version": "v1" }, { "created": "Mon, 29 Jun 1998 10:02:11 GMT", "version": "v2" }, { "created": "Mon, 23 Nov 1998 15:30:42 GMT", "version": "v3" }, { "created": "Thu, 1 Apr 1999 08:19:39 GMT", "version": "v4" }, { "created": "Tue, 4 May 1999 16:29:59 GMT", "version": "v5" }, { "created": "Tue, 11 May 1999 13:20:50 GMT", "version": "v6" }, { "created": "Tue, 28 Sep 1999 16:51:04 GMT", "version": "v7" } ]
2009-09-25
[ [ "Bertolini", "S.", "" ], [ "Eeg", "J. O.", "" ], [ "Fabbrichesi", "M.", "" ] ]
The real part of epsilon'/epsilon measures direct CP violation in the decays of the neutral kaons in two pions. It is a fundamental quantity which has justly attracted a great deal of theoretical as well as experimental work. Its determination may answer the question of whether CP violation is present only in the mass matrix of neutral kaons (the superweak scenario) or also at work directly in the decays. After a brief historical summary, we discuss the present and expected experimental sensitivities. In the light of these, we come to the problem of estimating epsilon'/epsilon in the standard model. We review the present (circa 1998) status of the theoretical predictions of epsilon'/epsilon. The short-distance part of the computation is now known to the next-to-leading order in QCD and QED and therefore well under control. On the other hand, the evaluation of the hadronic matrix element of the relevant operators is where most of the theoretical uncertainty still resides. We analyze the results of the currently most developed calculations. The values of the B_i parameters in the various approaches are discussed, together with the allowed range of the relevant combination of the Cabibbo-Kobayashi-Maskawa entries Im V_{td}V^*_{ts}. We conclude by summarizing and comparing all up-to-date predictions of epsilon'/epsilon. Because of the intrinsic uncertainties of the long-distance computations, values ranging from 10^{-4} to a few times 10^{-3} can be accounted for in the standard model. Since this range covers most of the present experimental uncertainty, it is unlikely that new physics effects can be disentangled from the standard model prediction. For updates on the review and additional material see http://www.he.sissa.it/review/.
1307.4323
C\'edric Lorc\'e
C. Lorc\'e (Orsay, IPN and Orsay, LPT)
The proton spin decomposition : path dependence and gauge symmetry
9 pages, contribution to the proceedings of the QCD Evolution 2013, May 6-10, JLab, Newport News, USA
null
10.1142/S2010194514600301
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the different types of decomposition of the proton spin. We stress that, despite their lack of uniqueness, the Chen et al. and Wakamatsu decompositions are perfectly measurable. We argue that a large part of the recent controversies boils down to the fact that there actually exist two types of gauge transformations in the Chen et al. approach, where physical and gauge degrees of freedom of the gauge potential are explicitly separated. By carefully distinguishing these two types of gauge transformations, one can easily understand how the concepts of gauge invariance, Stueckelberg symmetry, path dependence and measurability are linked to each other.
[ { "created": "Tue, 16 Jul 2013 16:07:50 GMT", "version": "v1" } ]
2014-06-25
[ [ "Lorcé", "C.", "", "Orsay, IPN and Orsay, LPT" ] ]
We discuss the different types of decomposition of the proton spin. We stress that, despite their lack of uniqueness, the Chen et al. and Wakamatsu decompositions are perfectly measurable. We argue that a large part of the recent controversies boils down to the fact that there actually exist two types of gauge transformations in the Chen et al. approach, where physical and gauge degrees of freedom of the gauge potential are explicitly separated. By carefully distinguishing these two types of gauge transformations, one can easily understand how the concepts of gauge invariance, Stueckelberg symmetry, path dependence and measurability are linked to each other.
2407.12377
Peter Risse
Peter Risse, Nasim Derakhshanian, Tomas Je\v{z}o, Karol Kova\v{r}\'ik, Aleksander Kusina
A Markov Chain Monte Carlo determination of Proton PDF uncertainties at NNLO
5 pages, 3 figures; contributed talk to DIS2024
null
null
MS-TP-24-16, IFJPAN-IV-2024-10
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
The current scientific standard in PDF uncertainty estimation relies either on repeated fits over artificially generated data to arrive at Monte Carlo samples of best fits or on the Hessian method, which uses a quadratic expansion of the figure of merit, the $\chi^2$-function. Markov Chain Monte Carlo methods allows one to access the uncertainties of PDFs without making use of quadratic approximations in a statistically sound procedure while at the same time preserving the correspondence between the sample and $\chi^2$-value. Rooted in Bayesian statistics the $\chi^2$-function is repeatedly sampled to obtain a set of PDFs that serves as a representation of the statistical distribution of the PDFs in their function space. After removing the dependence between the samples (the so-called autocorrelation) the set can be used to propagate the uncertainties to physical observables. The final result is an independent procedure to obtain PDF uncertainties that can be confronted by the state-of-the-art in order to ultimately arrive at a better understanding of the proton's structure.
[ { "created": "Wed, 17 Jul 2024 07:55:50 GMT", "version": "v1" }, { "created": "Mon, 22 Jul 2024 15:14:37 GMT", "version": "v2" } ]
2024-07-23
[ [ "Risse", "Peter", "" ], [ "Derakhshanian", "Nasim", "" ], [ "Ježo", "Tomas", "" ], [ "Kovařík", "Karol", "" ], [ "Kusina", "Aleksander", "" ] ]
The current scientific standard in PDF uncertainty estimation relies either on repeated fits over artificially generated data to arrive at Monte Carlo samples of best fits or on the Hessian method, which uses a quadratic expansion of the figure of merit, the $\chi^2$-function. Markov Chain Monte Carlo methods allows one to access the uncertainties of PDFs without making use of quadratic approximations in a statistically sound procedure while at the same time preserving the correspondence between the sample and $\chi^2$-value. Rooted in Bayesian statistics the $\chi^2$-function is repeatedly sampled to obtain a set of PDFs that serves as a representation of the statistical distribution of the PDFs in their function space. After removing the dependence between the samples (the so-called autocorrelation) the set can be used to propagate the uncertainties to physical observables. The final result is an independent procedure to obtain PDF uncertainties that can be confronted by the state-of-the-art in order to ultimately arrive at a better understanding of the proton's structure.
hep-ph/9902437
Johan Bijnens
Johan Bijnens (Lund), Gilberto Colangelo (Zurich) and Gerhard Ecker (Vienna)
The Mesonic Chiral Lagrangian of Order $p^6$
21 pages, uses longtable.sty, one more contact term found, extensive renumbering of 3 flavour terms
JHEP 9902:020,1999
10.1088/1126-6708/1999/02/020
LU TP 99-02, UWThPh-1999-02, ZU--TH 9/99
hep-ph
null
We construct the effective chiral Lagrangian for chiral perturbation theory in the mesonic even-intrinsic-parity sector at order $p^6$. The Lagrangian contains 112 in principle measurable + 3 contact terms for the general case of $n$ light flavours, 90+4 for three and 53+4 for two flavours. The equivalence between equations of motion and field redefinitions to remove spurious terms in the Lagrangians is shown to all orders in the chiral expansion. We also discuss and implement other methods for reducing the number of terms to a minimal set.
[ { "created": "Tue, 23 Feb 1999 08:08:28 GMT", "version": "v1" }, { "created": "Fri, 9 Apr 1999 12:03:00 GMT", "version": "v2" } ]
2010-02-03
[ [ "Bijnens", "Johan", "", "Lund" ], [ "Colangelo", "Gilberto", "", "Zurich" ], [ "Ecker", "Gerhard", "", "Vienna" ] ]
We construct the effective chiral Lagrangian for chiral perturbation theory in the mesonic even-intrinsic-parity sector at order $p^6$. The Lagrangian contains 112 in principle measurable + 3 contact terms for the general case of $n$ light flavours, 90+4 for three and 53+4 for two flavours. The equivalence between equations of motion and field redefinitions to remove spurious terms in the Lagrangians is shown to all orders in the chiral expansion. We also discuss and implement other methods for reducing the number of terms to a minimal set.
2311.00672
Yiyu Zhou
Zhong-Bo Kang, Hongxi Xing, Fanyi Zhao and Yiyu Zhou
Polarized fragmenting jet functions in Inclusive and Exclusive Jet Production
49 pages, 9 figures
JHEP 03, 142 (2024)
10.1007/JHEP03(2024)142
MIT-CTP/5633
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
In this work, we present a complete theoretical framework for analyzing the distribution of polarized hadrons within jets, with and without measuring the transverse momentum relative to the standard jet axis. Using soft-collinear effective theory (SCET), we derive the factorization and provide the theoretical calculation of both semi-inclusive and exclusive fragmenting jet functions (FJFs) under longitudinal and transverse polarization. With the polarized FJFs, one gains access to a variety of new observables that can be used for extracting both collinear and transverse momentum dependent parton distribution functions (PDFs) and fragmentation functions (FFs). As examples, we provide numerical results for the spin asymmetry $A_{TU,T}^{\cos(\phi _S - \hat{\phi}_{S_h})}$ from polarized semi-inclusive hadron-in-jet production in polarized $pp$ collisions at RHIC kinematics, where a transversely polarized quark would lead to the transverse spin of the final-state hadron inside the jet and is thus sensitive to the transversity fragmentation functions. Similarly, another spin asymmetry, $A_{TU, L}^{\cos(\phi _q - \phi _{S})}$ from polarized exclusive hadron-in-jet production in polarized $ep$ collisions at EIC kinematics would allow us to access the helicity fragmentation functions. These observables demonstrate promising potential in investigating transverse momentum dependent PDFs and FFs and are worthwhile for further measurements.
[ { "created": "Wed, 1 Nov 2023 17:22:31 GMT", "version": "v1" }, { "created": "Fri, 29 Mar 2024 12:38:02 GMT", "version": "v2" }, { "created": "Sun, 5 May 2024 07:46:05 GMT", "version": "v3" } ]
2024-06-06
[ [ "Kang", "Zhong-Bo", "" ], [ "Xing", "Hongxi", "" ], [ "Zhao", "Fanyi", "" ], [ "Zhou", "Yiyu", "" ] ]
In this work, we present a complete theoretical framework for analyzing the distribution of polarized hadrons within jets, with and without measuring the transverse momentum relative to the standard jet axis. Using soft-collinear effective theory (SCET), we derive the factorization and provide the theoretical calculation of both semi-inclusive and exclusive fragmenting jet functions (FJFs) under longitudinal and transverse polarization. With the polarized FJFs, one gains access to a variety of new observables that can be used for extracting both collinear and transverse momentum dependent parton distribution functions (PDFs) and fragmentation functions (FFs). As examples, we provide numerical results for the spin asymmetry $A_{TU,T}^{\cos(\phi _S - \hat{\phi}_{S_h})}$ from polarized semi-inclusive hadron-in-jet production in polarized $pp$ collisions at RHIC kinematics, where a transversely polarized quark would lead to the transverse spin of the final-state hadron inside the jet and is thus sensitive to the transversity fragmentation functions. Similarly, another spin asymmetry, $A_{TU, L}^{\cos(\phi _q - \phi _{S})}$ from polarized exclusive hadron-in-jet production in polarized $ep$ collisions at EIC kinematics would allow us to access the helicity fragmentation functions. These observables demonstrate promising potential in investigating transverse momentum dependent PDFs and FFs and are worthwhile for further measurements.
hep-ph/9712213
Marco Aurelio Diaz
Marco Aurelio Diaz
R--Parity Breaking in Minimal Supergravity
5 pages including 2 figures, Latex. Talk given at the International Europhysics Conference on High Energy Physics, EPS-HEP-1997, 19-26 August 1997, Jerusalem. Small change in the acknowledgments
null
null
IFIC/97-93, FTUV/97-63
hep-ph
null
We consider the Minimal Supergravity Model with universality of scalar and gaugino masses plus an extra bilinear term in the superpotential which breaks R-Parity and lepton number. We explicitly check the consistency of this model with the radiative breaking of the electroweak symmetry. A neutrino mass is radiatively induced, and large Higgs-Lepton mixings are compatible with its experimental bound. We also study briefly the lightest Higgs mass. This one-parameter extension of SUGRA-MSSM is the simplest way of introducing R-parity violation.
[ { "created": "Mon, 1 Dec 1997 11:55:45 GMT", "version": "v1" }, { "created": "Tue, 2 Dec 1997 13:51:08 GMT", "version": "v2" } ]
2007-05-23
[ [ "Diaz", "Marco Aurelio", "" ] ]
We consider the Minimal Supergravity Model with universality of scalar and gaugino masses plus an extra bilinear term in the superpotential which breaks R-Parity and lepton number. We explicitly check the consistency of this model with the radiative breaking of the electroweak symmetry. A neutrino mass is radiatively induced, and large Higgs-Lepton mixings are compatible with its experimental bound. We also study briefly the lightest Higgs mass. This one-parameter extension of SUGRA-MSSM is the simplest way of introducing R-parity violation.
1402.7074
Tongyan Lin
Asher Berlin, Tongyan Lin, and Lian-Tao Wang
Mono-Higgs Detection of Dark Matter at the LHC
11 pages
null
10.1007/JHEP06(2014)078
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or photon, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan beta and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.
[ { "created": "Thu, 27 Feb 2014 21:00:05 GMT", "version": "v1" } ]
2015-06-18
[ [ "Berlin", "Asher", "" ], [ "Lin", "Tongyan", "" ], [ "Wang", "Lian-Tao", "" ] ]
Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or photon, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan beta and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.
hep-ph/9609505
Shoichi Sasaki Rcnp
Shoichi Sasaki, Hideo Suganuma and Hiroshi Toki (RCNP, Osaka Univ.)
Finite Temperature SD Equation for Chiral Symmetry Restoration in Dual Ginzburg-Landau Theory
Talk presented at International Conference on Quark Confinement and the Hadron Spectrum II, Como, Italy, 26-29 Jun 1996. Latex, uses epsf.tex and sprocl.sty, 4 pages, 2 postscript figures included
null
null
null
hep-ph
null
We study the chiral phase transition at $T\neq 0$ in the dual Ginzburg-Landau theory using the Schwinger-Dyson (SD) equation. In order to solve the SD equation at $T\neq 0$, we provide a new ansatz for the quark self-energy in the imaginary-time formalism. The recovery of the chiral symmetry is found at $T_{_{C}}\sim 100 MeV$ with realistic parameters, which are set by reproducing the values of the string tension $\sqrt{\sigma}\simeq 0.44 GeV$ and the chiral condensate $< {\bar q}q > \simeq -(250 MeV}^{3}$ at $T=0$.
[ { "created": "Fri, 27 Sep 1996 15:07:12 GMT", "version": "v1" }, { "created": "Wed, 23 Oct 1996 08:38:58 GMT", "version": "v2" } ]
2016-09-06
[ [ "Sasaki", "Shoichi", "", "RCNP, Osaka Univ." ], [ "Suganuma", "Hideo", "", "RCNP, Osaka Univ." ], [ "Toki", "Hiroshi", "", "RCNP, Osaka Univ." ] ]
We study the chiral phase transition at $T\neq 0$ in the dual Ginzburg-Landau theory using the Schwinger-Dyson (SD) equation. In order to solve the SD equation at $T\neq 0$, we provide a new ansatz for the quark self-energy in the imaginary-time formalism. The recovery of the chiral symmetry is found at $T_{_{C}}\sim 100 MeV$ with realistic parameters, which are set by reproducing the values of the string tension $\sqrt{\sigma}\simeq 0.44 GeV$ and the chiral condensate $< {\bar q}q > \simeq -(250 MeV}^{3}$ at $T=0$.
1605.09671
Mat\'ias Reynoso M
Mat\'ias M. Reynoso and Oscar A. Sampayo
Propagation of high-energy neutrinos in a background of ultralight scalar dark matter
11 pages, 11 figures, accepted for publication in Astroparticle Physics
null
10.1016/j.astropartphys.2016.05.004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If high-energy neutrinos propagate in a background of ultralight scalar field particles of dark matter ($m_\varphi \sim 10^{-23}$eV), neutrino-dark matter interactions can play a role and affect the neutrino flux. In this work we analyse this effect using transport equations that account for the neutrino regeneration as well as absorption, and we consider the neutrino flux propagation in the extragalactic medium and also through the galactic halo of dark matter. We show the results for the final flux to arrive on Earth for different cases of point and diffuse neutrino fluxes. {We conclude that this type of neutrino interactions with ultralight scalar particles as dark matter can yield very different results in the neutrino flux and in the flavor ratios that can be measured in neutrino detectors such as IceCube.
[ { "created": "Mon, 30 May 2016 13:36:44 GMT", "version": "v1" } ]
2016-06-01
[ [ "Reynoso", "Matías M.", "" ], [ "Sampayo", "Oscar A.", "" ] ]
If high-energy neutrinos propagate in a background of ultralight scalar field particles of dark matter ($m_\varphi \sim 10^{-23}$eV), neutrino-dark matter interactions can play a role and affect the neutrino flux. In this work we analyse this effect using transport equations that account for the neutrino regeneration as well as absorption, and we consider the neutrino flux propagation in the extragalactic medium and also through the galactic halo of dark matter. We show the results for the final flux to arrive on Earth for different cases of point and diffuse neutrino fluxes. {We conclude that this type of neutrino interactions with ultralight scalar particles as dark matter can yield very different results in the neutrino flux and in the flavor ratios that can be measured in neutrino detectors such as IceCube.
2212.11505
Bao-Dong Sun
H. Alharazin, B.-D. Sun, E. Epelbaum, J. Gegelia, and U.-G. Mei{\ss}ner
Local spatial densities for composite spin-3/2 systems
null
JHEP02(2023)163
10.1007/JHEP02(2023)163
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
The definition of local spatial densities by using sharply localized one-particle states is applied to spin-3/2 systems. Matrix elements of the electromagnetic current and the energy-momentum tensor are considered and integral expressions of associated spatial distributions in terms of form factors are derived.
[ { "created": "Thu, 22 Dec 2022 06:32:09 GMT", "version": "v1" }, { "created": "Thu, 5 Jan 2023 09:30:28 GMT", "version": "v2" }, { "created": "Mon, 6 Feb 2023 14:21:23 GMT", "version": "v3" }, { "created": "Tue, 21 Feb 2023 13:21:02 GMT", "version": "v4" } ]
2023-02-22
[ [ "Alharazin", "H.", "" ], [ "Sun", "B. -D.", "" ], [ "Epelbaum", "E.", "" ], [ "Gegelia", "J.", "" ], [ "Meißner", "U. -G.", "" ] ]
The definition of local spatial densities by using sharply localized one-particle states is applied to spin-3/2 systems. Matrix elements of the electromagnetic current and the energy-momentum tensor are considered and integral expressions of associated spatial distributions in terms of form factors are derived.
hep-ph/0311194
Giuseppe Bozzi
G.Bozzi
Q_T resummation in Higgs boson production at the LHC
5 pages, 2 figures,. Talk given in italian at "Incontri sulla Fisica delle Alte Energie", Lecce, Italy, 23-26 April 2003
null
null
null
hep-ph hep-ex
null
When considering the transverse momentum distribution (q_T) of the Higgs boson production it is necessary to separate the small q_T region (q_T << M_H) from the medium and large (q_T > M_H) one, the former being treated by means of resummation techniques of logaritmhically-enhanced contributions and the latter by fixed-order perturbation theory. Then these two approaches have to be consistently matched to avoid double-counting in the intermediate q_T region. Here soft gluon resummation is implemented up to NNLL order and the matching to the corresponding NLO perturbative result is performed. Numerical results are shown for the LHC. The main features of the differential distribution turn out to be quite stable with respect to perturbative uncertainties.
[ { "created": "Fri, 14 Nov 2003 15:40:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bozzi", "G.", "" ] ]
When considering the transverse momentum distribution (q_T) of the Higgs boson production it is necessary to separate the small q_T region (q_T << M_H) from the medium and large (q_T > M_H) one, the former being treated by means of resummation techniques of logaritmhically-enhanced contributions and the latter by fixed-order perturbation theory. Then these two approaches have to be consistently matched to avoid double-counting in the intermediate q_T region. Here soft gluon resummation is implemented up to NNLL order and the matching to the corresponding NLO perturbative result is performed. Numerical results are shown for the LHC. The main features of the differential distribution turn out to be quite stable with respect to perturbative uncertainties.
2112.06083
Ekaterina Kriukova
S. Demidov, D. Gorbunov and E. Kriukova
Gravitational waves from first-order electroweak phase transition in a model with light sgoldstinos
30 pages, 5 figures, 3 tables; the estimate of uncertainties in GW spectra added, figures and tables updated; published version
JHEP 07 (2022) 061
10.1007/JHEP07(2022)061
INR-TH-2021-023
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study previously unexplored possibility of triggering the first order electroweak phase transition (EWPT) by interactions of the Standard Model (SM) particles with the sector responsible for low scale supersymmetry breaking. The low-energy theory apart from the SM particles contains additional scalar degrees of freedom -- sgoldstinos -- which contribute to the effective scalar potential and thus can trigger the first order EWPT. Remarkably, the latter requires only moderate couplings in the scalar sector. The perturbative description in terms of the effective theory seems formally to be applicable upto the scale of supersymmetry breaking: the Landau pole in the scalar sector is above $10^8$-$10^9$ GeV. We calculate the gravitational wave signal generated at this transition (it can be tested, e.g. by LISA, BBO and DECIGO) and briefly discuss the collider phenomenology of this scenario.
[ { "created": "Sat, 11 Dec 2021 22:24:16 GMT", "version": "v1" }, { "created": "Wed, 13 Jul 2022 11:05:58 GMT", "version": "v2" } ]
2022-07-14
[ [ "Demidov", "S.", "" ], [ "Gorbunov", "D.", "" ], [ "Kriukova", "E.", "" ] ]
We study previously unexplored possibility of triggering the first order electroweak phase transition (EWPT) by interactions of the Standard Model (SM) particles with the sector responsible for low scale supersymmetry breaking. The low-energy theory apart from the SM particles contains additional scalar degrees of freedom -- sgoldstinos -- which contribute to the effective scalar potential and thus can trigger the first order EWPT. Remarkably, the latter requires only moderate couplings in the scalar sector. The perturbative description in terms of the effective theory seems formally to be applicable upto the scale of supersymmetry breaking: the Landau pole in the scalar sector is above $10^8$-$10^9$ GeV. We calculate the gravitational wave signal generated at this transition (it can be tested, e.g. by LISA, BBO and DECIGO) and briefly discuss the collider phenomenology of this scenario.
2109.05440
Sanjin Beni\'c
Sanjin Beni\'c, Yoshitaka Hatta, Abhiram Kaushik, Hsiang-nan Li
The $g_T(x)$ contribution to single spin asymmetries in SIDIS
28 pages, 8 figures
null
10.1103/PhysRevD.104.094027
ZTF-EP-21-05
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by a novel origin of transverse single spin asymmetry (SSA) in semi-inclusive Deep Inelastic Scattering (SIDIS) uncovered by some of us, we quantitatively investigate its impact on the theoretical understanding of the mechanism responsible for SSA. This new contribution from the quark-initiated channel first appears in two-loop perturbation theory and involves the $g_T(x)$ distribution. We point out another entirely analogous piece from the gluon-initiated channel proportional to the gluon helicity distribution $\Delta G(x)$. Both contributions are solely expressed in terms of twist-two polarized parton distribution functions and twist-two fragmentation functions in the Wandzura-Wilczek approximation, such that they can be unambiguously evaluated without introducing free parameters. We make predictions for measurements of the asymmetries $A_{UT}$ at the future Electron-Ion Collider (EIC), and find that $A_{UT}$ associated with the $\sin (\phi_h-\phi_S)$, $\sin \phi_S$ and $\sin (2\phi_h-\phi_S)$ harmonics can reach up to 1-2\% even at the top EIC energy.
[ { "created": "Sun, 12 Sep 2021 06:25:03 GMT", "version": "v1" } ]
2021-12-01
[ [ "Benić", "Sanjin", "" ], [ "Hatta", "Yoshitaka", "" ], [ "Kaushik", "Abhiram", "" ], [ "Li", "Hsiang-nan", "" ] ]
Motivated by a novel origin of transverse single spin asymmetry (SSA) in semi-inclusive Deep Inelastic Scattering (SIDIS) uncovered by some of us, we quantitatively investigate its impact on the theoretical understanding of the mechanism responsible for SSA. This new contribution from the quark-initiated channel first appears in two-loop perturbation theory and involves the $g_T(x)$ distribution. We point out another entirely analogous piece from the gluon-initiated channel proportional to the gluon helicity distribution $\Delta G(x)$. Both contributions are solely expressed in terms of twist-two polarized parton distribution functions and twist-two fragmentation functions in the Wandzura-Wilczek approximation, such that they can be unambiguously evaluated without introducing free parameters. We make predictions for measurements of the asymmetries $A_{UT}$ at the future Electron-Ion Collider (EIC), and find that $A_{UT}$ associated with the $\sin (\phi_h-\phi_S)$, $\sin \phi_S$ and $\sin (2\phi_h-\phi_S)$ harmonics can reach up to 1-2\% even at the top EIC energy.
1810.00541
Run-Hui Li
Li-Juan Jiang, Bei He, Run-Hui Li
Weak Decays of Doubly Heavy Baryons: ${\cal B}_{cc}\to {\cal B}_c V$
29 pages, 5 figures, 7 tables; version published in EPJC
null
10.1140/epjc/s10052-018-6445-1
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weak decays of a spin-$1/2$ doubly charm baryon (${\cal B}_{cc}$) to a spin-$1/2$ singly charm baryon (${\cal B}_c$) and a light vector meson ($V$) are studied under a phenomenological scheme. The contributions are classified into different topological diagrams, among which the short distance ones are calculated under the factorization hypothesis, and the long distance contributions are modelled as final-state interactions (FSIs) which are estimated with the one-particle-exchange model. In calculation the topological contributions tend to fall in a hierarchy. The branching fractions or decay widths are estimated, and it indicates that $\Xi_{cc}^+\to\Xi_c^+\pi^+\pi^-$ and $\Omega_{cc}^{+}\rightarrow\Xi_{c}^{+}K^-\pi^+$ can be used as candidate decays for searching $\Xi_{cc}^+$ and $\Omega_{cc}^+$. Some decays that are mainly activated by the long distance effects are found, observation on which in future experiments can help to understand the role of FSIs in charm baryon decays.
[ { "created": "Mon, 1 Oct 2018 06:18:32 GMT", "version": "v1" }, { "created": "Fri, 23 Nov 2018 01:08:08 GMT", "version": "v2" } ]
2018-11-26
[ [ "Jiang", "Li-Juan", "" ], [ "He", "Bei", "" ], [ "Li", "Run-Hui", "" ] ]
The weak decays of a spin-$1/2$ doubly charm baryon (${\cal B}_{cc}$) to a spin-$1/2$ singly charm baryon (${\cal B}_c$) and a light vector meson ($V$) are studied under a phenomenological scheme. The contributions are classified into different topological diagrams, among which the short distance ones are calculated under the factorization hypothesis, and the long distance contributions are modelled as final-state interactions (FSIs) which are estimated with the one-particle-exchange model. In calculation the topological contributions tend to fall in a hierarchy. The branching fractions or decay widths are estimated, and it indicates that $\Xi_{cc}^+\to\Xi_c^+\pi^+\pi^-$ and $\Omega_{cc}^{+}\rightarrow\Xi_{c}^{+}K^-\pi^+$ can be used as candidate decays for searching $\Xi_{cc}^+$ and $\Omega_{cc}^+$. Some decays that are mainly activated by the long distance effects are found, observation on which in future experiments can help to understand the role of FSIs in charm baryon decays.
1410.7475
Tom Melia
Michelangelo Mangano and Tom Melia
Rare exclusive hadronic W decays in a t-tbar environment
9 pages, 7 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The large cross section for t-tbar production at the LHC and at any future hadron collider provides a high-statistics and relatively clean environment for a study of W boson properties: after tagging on a leptonic decay of one of the Ws and the two b-jets, an additional W still remains in the event. We study the prospect of making the first exclusive hadronic decay of a fundamental boson of the standard model, using the decay modes W to pi gamma and W to pi pi pi, and other related decays. By using strong isolation criteria, which we impose by searching for jets with a single particle constituent, we show that the three particle hadronic W decays have potential to be measured at the LHC. The possibility of measuring an involved spectrum of decay products could considerably expand our knowledge of how the W decays, and experimental techniques acquired in making these measurements would be useful for application to future measurements of exclusive hadronic Higgs boson decays.
[ { "created": "Tue, 28 Oct 2014 00:54:15 GMT", "version": "v1" } ]
2014-10-29
[ [ "Mangano", "Michelangelo", "" ], [ "Melia", "Tom", "" ] ]
The large cross section for t-tbar production at the LHC and at any future hadron collider provides a high-statistics and relatively clean environment for a study of W boson properties: after tagging on a leptonic decay of one of the Ws and the two b-jets, an additional W still remains in the event. We study the prospect of making the first exclusive hadronic decay of a fundamental boson of the standard model, using the decay modes W to pi gamma and W to pi pi pi, and other related decays. By using strong isolation criteria, which we impose by searching for jets with a single particle constituent, we show that the three particle hadronic W decays have potential to be measured at the LHC. The possibility of measuring an involved spectrum of decay products could considerably expand our knowledge of how the W decays, and experimental techniques acquired in making these measurements would be useful for application to future measurements of exclusive hadronic Higgs boson decays.
hep-ph/9912500
null
M. Wakamatsu and T. Watabe
Spin and Orbital Angular Momentum Distribution Functions of the Nucleon
16 pages, latex, 3 eps figures, the revised version to appear in Physical Review D
Phys.Rev. D62 (2000) 054009
10.1103/PhysRevD.62.054009
OU-HEP-338
hep-ph
null
A theoretical prediction is given for the spin and orbital angular momentum distribution functions of the nucleon within the framework of an effective quark model of QCD, i.e. the chiral quark soliton model. An outstanding feature of the model is that it predicts fairly small quark spin fraction of the nucleon $\Delta \Sigma \simeq 0.35$, which in turn dictates that the remaining 65% of the nucleon spin is carried by the orbital angular momentum of quarks and antiquarks at the model energy scale of $Q^2 \simeq 0.3 {GeV}^2$. This large orbital angular momentum necessarily affects the scenario of scale dependence of the nucleon spin contents in a drastic way.
[ { "created": "Fri, 24 Dec 1999 07:44:56 GMT", "version": "v1" }, { "created": "Tue, 28 Dec 1999 02:02:48 GMT", "version": "v2" }, { "created": "Thu, 20 Apr 2000 06:27:35 GMT", "version": "v3" } ]
2009-10-31
[ [ "Wakamatsu", "M.", "" ], [ "Watabe", "T.", "" ] ]
A theoretical prediction is given for the spin and orbital angular momentum distribution functions of the nucleon within the framework of an effective quark model of QCD, i.e. the chiral quark soliton model. An outstanding feature of the model is that it predicts fairly small quark spin fraction of the nucleon $\Delta \Sigma \simeq 0.35$, which in turn dictates that the remaining 65% of the nucleon spin is carried by the orbital angular momentum of quarks and antiquarks at the model energy scale of $Q^2 \simeq 0.3 {GeV}^2$. This large orbital angular momentum necessarily affects the scenario of scale dependence of the nucleon spin contents in a drastic way.
2311.09621
Gong-Ming Yu
Gongming Yu, Xinyu Li, Xinghang Zhang, Zhongxia Zhao, Haitao Yang
Production of dileptons in ultra-peripheral heavy ion collisions with two-photon processes
11 pages, 6 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the photoproduction process of dileptons in heavy ion collision at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energys. The equivalent photon approximation, which equates the electromagnetic field of high-energy charged particles to the virtual photon flux, is used to calculate the processes of dileptons production. The numerical results demonstrate that the experimental study of dileptons in ultra-peripheral collisions is feasible at RHIC and LHC energies.
[ { "created": "Thu, 16 Nov 2023 07:05:25 GMT", "version": "v1" }, { "created": "Mon, 15 Apr 2024 07:39:27 GMT", "version": "v2" } ]
2024-04-16
[ [ "Yu", "Gongming", "" ], [ "Li", "Xinyu", "" ], [ "Zhang", "Xinghang", "" ], [ "Zhao", "Zhongxia", "" ], [ "Yang", "Haitao", "" ] ]
We study the photoproduction process of dileptons in heavy ion collision at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energys. The equivalent photon approximation, which equates the electromagnetic field of high-energy charged particles to the virtual photon flux, is used to calculate the processes of dileptons production. The numerical results demonstrate that the experimental study of dileptons in ultra-peripheral collisions is feasible at RHIC and LHC energies.
hep-ph/0205043
Adriano Doff Sotta Gomes
A. Doff, A. A. Natale
Energy criterion to select the behavior of dynamical masses in technicolor models
4 pages, 3 figures; to appear in Phys. Lett. B
Phys.Lett. B537 (2002) 275-279
10.1016/S0370-2693(02)01906-8
null
hep-ph
null
We propose a quite general ansatz for the dynamical mass in technicolor models. We impose on this ansatz the condition for formation of the tightest composite boson state, or the criterion that it should lead to the deepest minimum of energy. This criterion indicates a particular form of the technifermion self energy.
[ { "created": "Sun, 5 May 2002 17:49:00 GMT", "version": "v1" } ]
2009-11-07
[ [ "Doff", "A.", "" ], [ "Natale", "A. A.", "" ] ]
We propose a quite general ansatz for the dynamical mass in technicolor models. We impose on this ansatz the condition for formation of the tightest composite boson state, or the criterion that it should lead to the deepest minimum of energy. This criterion indicates a particular form of the technifermion self energy.
1808.02597
Shu-Min Zhao
Tao Guo, Shu-Min Zhao, Xing-Xing Dong, Chun-Gui Duan, Tai-Fu Feng
Muon conversion to electron in nuclei within the BLMSSM
20pages, 10figures
null
10.1140/epjc/s10052-018-6413-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a supersymmetric extension of the standard model with local gauged baryon and lepton numbers (BLMSSM), there are new sources for lepton flavor violation, because the right-handed neutrinos, new gauginos and Higgs are introduced. We investigate muon conversion to electron in nuclei within the BLMSSM in detail. The numerical results indicate that the $\mu \rightarrow e $ conversion rates in nuclei within the BLMSSM can reach the experimental upper bound, which may be detected in the future experiments.
[ { "created": "Wed, 8 Aug 2018 01:56:29 GMT", "version": "v1" }, { "created": "Sun, 7 Oct 2018 07:18:04 GMT", "version": "v2" } ]
2018-12-05
[ [ "Guo", "Tao", "" ], [ "Zhao", "Shu-Min", "" ], [ "Dong", "Xing-Xing", "" ], [ "Duan", "Chun-Gui", "" ], [ "Feng", "Tai-Fu", "" ] ]
In a supersymmetric extension of the standard model with local gauged baryon and lepton numbers (BLMSSM), there are new sources for lepton flavor violation, because the right-handed neutrinos, new gauginos and Higgs are introduced. We investigate muon conversion to electron in nuclei within the BLMSSM in detail. The numerical results indicate that the $\mu \rightarrow e $ conversion rates in nuclei within the BLMSSM can reach the experimental upper bound, which may be detected in the future experiments.
hep-ph/0702249
C. Q. Geng
C.Q. Geng, Y.K. Hsiao and J.N. Ng
Study of $B\to p\bar{p}K^*$ and $B\to p\bar{p}\rho$
13 pages, one figure, version to be published in PRD
Phys.Rev.D75:094013,2007
10.1103/PhysRevD.75.094013
null
hep-ph
null
We study the three-body baryonic B decays of $B\to p\bar{p}(K^{*},\rho)$ in the standard model. The baryonic matrix elements are calculated in terms of the SU(3) flavor symmetry and the QCD power counting rules within the the perturbative QCD. We find that the decay branching ratios, angular and direct CP asymmetries of ($B^{-}\to p\bar{p}K^{*-}, \bar{B}^{0}\to p\bar{p}K^{*0}, B^{-}\to p\bar{p}\rho^{-}$) are around $(6,1,30)\times 10^{-6}$, $(13,-27,11)%$ and $(22,1,-3)%$, which are consistent with the current BaBar and Belle data, respectively. The large values of the branching ratio in $B^{-}\to p\bar{p}\rho^{-}$ and the direct CP asymmetry in $B^{\pm}\to p\bar{p}K^{*\pm}$ are useful to test the standard model and search for new physics.
[ { "created": "Mon, 26 Feb 2007 17:52:03 GMT", "version": "v1" }, { "created": "Fri, 20 Apr 2007 15:40:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Geng", "C. Q.", "" ], [ "Hsiao", "Y. K.", "" ], [ "Ng", "J. N.", "" ] ]
We study the three-body baryonic B decays of $B\to p\bar{p}(K^{*},\rho)$ in the standard model. The baryonic matrix elements are calculated in terms of the SU(3) flavor symmetry and the QCD power counting rules within the the perturbative QCD. We find that the decay branching ratios, angular and direct CP asymmetries of ($B^{-}\to p\bar{p}K^{*-}, \bar{B}^{0}\to p\bar{p}K^{*0}, B^{-}\to p\bar{p}\rho^{-}$) are around $(6,1,30)\times 10^{-6}$, $(13,-27,11)%$ and $(22,1,-3)%$, which are consistent with the current BaBar and Belle data, respectively. The large values of the branching ratio in $B^{-}\to p\bar{p}\rho^{-}$ and the direct CP asymmetry in $B^{\pm}\to p\bar{p}K^{*\pm}$ are useful to test the standard model and search for new physics.
1810.03891
Harri Waltari
Arindam Chatterjee, Mariana Frank, Benjamin Fuks, Katri Huitu, Subhadeep Mondal, Santosh Kumar Rai and Harri Waltari
Multileptonic signals of co-annihilating left-right supersymmetric dark matter
20 pages, 4 figures, revised version
Phys. Rev. D 99, 035017 (2019)
10.1103/PhysRevD.99.035017
CUMQ/HEP 198, HIP-2018-20-TH, HRI-RECAPP-2018-11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a comprehensive dark matter analysis of left-right supersymmetric scenarios that includes constraints from dark matter direct and indirect detection experiments and that presents distinctive features from those available in minimal supersymmetry. We concentrate on dark matter candidates which, while satisfying all constraints, are different from those of the minimal supersymmetric standard model. We consider in our analysis all possible co-annihilation channels relevant for setups in which several states are light and nearly degenerate, and devise a set of representative benchmark points, requiring co-annihilations, which satisfy all restrictions. We then study their consequent LHC signals, which exhibit promising new multileptonic signatures involving $W_R$, that if observed, would provide a strong support for left-right supersymmetry.
[ { "created": "Tue, 9 Oct 2018 10:19:29 GMT", "version": "v1" }, { "created": "Thu, 31 Jan 2019 15:28:45 GMT", "version": "v2" } ]
2019-02-20
[ [ "Chatterjee", "Arindam", "" ], [ "Frank", "Mariana", "" ], [ "Fuks", "Benjamin", "" ], [ "Huitu", "Katri", "" ], [ "Mondal", "Subhadeep", "" ], [ "Rai", "Santosh Kumar", "" ], [ "Waltari", "Harri", "" ] ]
We perform a comprehensive dark matter analysis of left-right supersymmetric scenarios that includes constraints from dark matter direct and indirect detection experiments and that presents distinctive features from those available in minimal supersymmetry. We concentrate on dark matter candidates which, while satisfying all constraints, are different from those of the minimal supersymmetric standard model. We consider in our analysis all possible co-annihilation channels relevant for setups in which several states are light and nearly degenerate, and devise a set of representative benchmark points, requiring co-annihilations, which satisfy all restrictions. We then study their consequent LHC signals, which exhibit promising new multileptonic signatures involving $W_R$, that if observed, would provide a strong support for left-right supersymmetry.
hep-ph/0605186
Eligio Lisi
G.L. Fogli, E. Lisi, A. Marrone, A. Palazzo (U. of Bari & INFN, Bari)
Solar Neutrinos (with a tribute to John. N. Bahcall)
12 pages, inclusing 9 figures. Presented by G.L. Fogli at 3rd International Workshop on NO-VE: Neutrino Oscillations in Venice: 50 Years after the Neutrino Experimental Discovery, Venice, Italy, 7-10 Feb 2006
null
null
null
hep-ph astro-ph hep-ex nucl-ex
null
John N. Bahcall championed solar neutrino physics for many years. Thanks to his pioneering and long-lasting contributions, this field of research has not only reached maturity, but has also opened a new window on physics beyond the standard electroweak model through the phenomenon of neutrino flavor oscillations. We briefly outline some recent accomplishments in the field, and also discuss a couple of issues that do not seem to fit in the ``standard picture,'' namely, the chemical controversy at the solar surface, and possible implications of recent gallium radioactive source experiments.
[ { "created": "Tue, 16 May 2006 13:08:26 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fogli", "G. L.", "", "U. of Bari & INFN, Bari" ], [ "Lisi", "E.", "", "U. of Bari & INFN, Bari" ], [ "Marrone", "A.", "", "U. of Bari & INFN, Bari" ], [ "Palazzo", "A.", "", "U. of Bari & INFN, Bari" ] ]
John N. Bahcall championed solar neutrino physics for many years. Thanks to his pioneering and long-lasting contributions, this field of research has not only reached maturity, but has also opened a new window on physics beyond the standard electroweak model through the phenomenon of neutrino flavor oscillations. We briefly outline some recent accomplishments in the field, and also discuss a couple of issues that do not seem to fit in the ``standard picture,'' namely, the chemical controversy at the solar surface, and possible implications of recent gallium radioactive source experiments.
1910.04163
Jacob Leedom
Keisuke Harigaya and Jacob M. Leedom
QCD Axion Dark Matter from a Late Time Phase Transition
v2: 18 pages, 4 figures
null
10.1007/JHEP06(2020)034
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility that the Peccei-Quinn phase transition occurs at a temperature far below the symmetry breaking scale. Low phase transition temperatures are typical in supersymmetric theories, where symmetry breaking fields have small masses. We find that QCD axions are abundantly produced just after the phase transition. The observed dark matter abundance is reproduced even if the decay constant is much lower than $10^{11}$ GeV. The produced axions tend to be warm. For some range of the decay constant, the effect of the predicted warmness on structure formation can be confirmed by future observations of 21 cm lines. A portion of parameter space requires a mixing between the Peccei-Quinn symmetry breaking field and the Standard Model Higgs, and predicts an observable rate of rare Kaon decays.
[ { "created": "Wed, 9 Oct 2019 18:00:00 GMT", "version": "v1" }, { "created": "Thu, 18 Jun 2020 17:37:00 GMT", "version": "v2" } ]
2020-06-19
[ [ "Harigaya", "Keisuke", "" ], [ "Leedom", "Jacob M.", "" ] ]
We investigate the possibility that the Peccei-Quinn phase transition occurs at a temperature far below the symmetry breaking scale. Low phase transition temperatures are typical in supersymmetric theories, where symmetry breaking fields have small masses. We find that QCD axions are abundantly produced just after the phase transition. The observed dark matter abundance is reproduced even if the decay constant is much lower than $10^{11}$ GeV. The produced axions tend to be warm. For some range of the decay constant, the effect of the predicted warmness on structure formation can be confirmed by future observations of 21 cm lines. A portion of parameter space requires a mixing between the Peccei-Quinn symmetry breaking field and the Standard Model Higgs, and predicts an observable rate of rare Kaon decays.
1812.08623
Shoaib Munir
Rikard Enberg, William Klemm, Stefano Moretti, Shoaib Munir
Signatures of the Type-I 2HDM at the LHC
14 pages, 6 figures, 4 tables; Proceedings of the Corfu Summer Institute 2018 "School and Workshops on Elementary Particle Physics and Gravity" (CORFU2018)
null
null
KIAS-P18116
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the simplest extensions of the Standard Model (SM) is the two-Higgs-doublet model (2HDM), which contains two neutral Higgs bosons, in addition to a 125 GeV one, and a charged pair. At the Large Hadron Collider (LHC), gluon-induced processes are generally the most important modes for the resonant production of the SM-like Higgs boson as well as its pair-production, and it is generally considered to be the case also for an additional neutral Higgs boson possibly existing in nature. We show that for certain parameter configurations in the Type-I 2HDM, electroweak pair-production of the neutral Higgs states can dominate over the QCD-initiated production. Moreover, it is possible for the pair-production of the charged Higgs state along with a neutral one, which can only take place electroweakly, to have a substantial cross section. We delineate such 2HDM parameter space regions through its comprehensive numerical scanning, requiring their consistency with the most relevant theoretical and experimental constraints. We also highlight some specific di-Higgs signatures that can be probed at the LHC in order to establish the Type-I 2HDM as the underlying new physics model.
[ { "created": "Thu, 20 Dec 2018 15:03:28 GMT", "version": "v1" }, { "created": "Sun, 30 Dec 2018 12:55:37 GMT", "version": "v2" } ]
2019-01-01
[ [ "Enberg", "Rikard", "" ], [ "Klemm", "William", "" ], [ "Moretti", "Stefano", "" ], [ "Munir", "Shoaib", "" ] ]
One of the simplest extensions of the Standard Model (SM) is the two-Higgs-doublet model (2HDM), which contains two neutral Higgs bosons, in addition to a 125 GeV one, and a charged pair. At the Large Hadron Collider (LHC), gluon-induced processes are generally the most important modes for the resonant production of the SM-like Higgs boson as well as its pair-production, and it is generally considered to be the case also for an additional neutral Higgs boson possibly existing in nature. We show that for certain parameter configurations in the Type-I 2HDM, electroweak pair-production of the neutral Higgs states can dominate over the QCD-initiated production. Moreover, it is possible for the pair-production of the charged Higgs state along with a neutral one, which can only take place electroweakly, to have a substantial cross section. We delineate such 2HDM parameter space regions through its comprehensive numerical scanning, requiring their consistency with the most relevant theoretical and experimental constraints. We also highlight some specific di-Higgs signatures that can be probed at the LHC in order to establish the Type-I 2HDM as the underlying new physics model.
1607.06741
Miguel Crispim Rom\~ao
Bobby S. Acharya, Krzysztof Bozek, Miguel Crispim Rom\~ao, Stephen F. King, Chakrit Pongkitivanichkul
Neutrino mass from M Theory SO(10)
32 pages, 12 figures
null
10.1007/JHEP11(2016)173
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the origin of neutrino mass from $SO(10)$ arising from $M$ Theory compactified on a $G_2$-manifold. This is linked to the problem of the breaking of the extra $U(1)$ gauge group, in the $SU(5)\times U(1)$ subgroup of $SO(10)$, which we show can achieved via a (generalised) Kolda-Martin mechanism. The resulting neutrino masses arise from a combination of the seesaw mechanism and induced R-parity breaking contributions. The rather complicated neutrino mass matrix is analysed for one neutrino family and it is shown how phenomenologically acceptable neutrino masses can emerge.
[ { "created": "Fri, 22 Jul 2016 16:47:35 GMT", "version": "v1" } ]
2016-12-21
[ [ "Acharya", "Bobby S.", "" ], [ "Bozek", "Krzysztof", "" ], [ "Romão", "Miguel Crispim", "" ], [ "King", "Stephen F.", "" ], [ "Pongkitivanichkul", "Chakrit", "" ] ]
We study the origin of neutrino mass from $SO(10)$ arising from $M$ Theory compactified on a $G_2$-manifold. This is linked to the problem of the breaking of the extra $U(1)$ gauge group, in the $SU(5)\times U(1)$ subgroup of $SO(10)$, which we show can achieved via a (generalised) Kolda-Martin mechanism. The resulting neutrino masses arise from a combination of the seesaw mechanism and induced R-parity breaking contributions. The rather complicated neutrino mass matrix is analysed for one neutrino family and it is shown how phenomenologically acceptable neutrino masses can emerge.
hep-ph/9611242
Elena Boglione
M.R. Pennington
Calculating hadronic properties in strong QCD
6 Latex pages, 5 figures
null
null
null
hep-ph
null
This talk, given at the Second Workshop on ELFE Physics, St Malo, France, September 1996, presents a brief review of the progress that has been made in calculating the properties of hadrons in strong QCD.
[ { "created": "Tue, 5 Nov 1996 18:40:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Pennington", "M. R.", "" ] ]
This talk, given at the Second Workshop on ELFE Physics, St Malo, France, September 1996, presents a brief review of the progress that has been made in calculating the properties of hadrons in strong QCD.
1003.3819
Covi Laura
L. Covi
Gravitino Dark Matter and the ILC
5 pages, no figures. Contribution to the Proceedings of LC09, Perugia, 21-24 September 2009.
null
10.1393/ncc/i2010-10602-5
DESY 10-038
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the case of gravitino Dark Matter for stop, neutralino and sneutrino Next-to-Lightest Supersymmetric Particles and discuss prospects to investigate such scenarios at LHC and a Linear Collider.
[ { "created": "Fri, 19 Mar 2010 15:45:26 GMT", "version": "v1" } ]
2022-03-02
[ [ "Covi", "L.", "" ] ]
We review the case of gravitino Dark Matter for stop, neutralino and sneutrino Next-to-Lightest Supersymmetric Particles and discuss prospects to investigate such scenarios at LHC and a Linear Collider.
1311.6058
Bodo Lampe
Bodo Lampe
A microscopic Interpretation of the SM Higgs Mechanism
24 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model is presented where the Higgs mechanism of the Standard Model is deduced from the alignment of a strongly correlated fermion system in an internal space with $A_4$ symmetry. The ground state is constructed and its energy calculated. Finally, it is claimed that the model may be derived from a field theory in 6+1 dimensions.
[ { "created": "Sat, 23 Nov 2013 21:55:17 GMT", "version": "v1" }, { "created": "Sun, 8 Dec 2013 11:39:41 GMT", "version": "v2" }, { "created": "Mon, 26 Jan 2015 15:17:50 GMT", "version": "v3" } ]
2015-01-27
[ [ "Lampe", "Bodo", "" ] ]
A model is presented where the Higgs mechanism of the Standard Model is deduced from the alignment of a strongly correlated fermion system in an internal space with $A_4$ symmetry. The ground state is constructed and its energy calculated. Finally, it is claimed that the model may be derived from a field theory in 6+1 dimensions.
hep-ph/0606272
Leszek Motyka
H. Kowalski, L. Motyka and G. Watt
Exclusive diffractive processes at HERA within the dipole picture
48 pages, 28 figures, the final version to appear in Physical Review D
Phys.Rev.D74:074016,2006
10.1103/PhysRevD.74.074016
DESY 06-095
hep-ph
null
We present a simultaneous analysis, within an impact parameter dependent saturated dipole model, of exclusive diffractive vector meson (J/psi, phi and rho) production, deeply virtual Compton scattering and the total gamma* p cross section data measured at HERA. Various cross sections measured as a function of the kinematic variables Q^2, W and t are well described, with little sensitivity to the details of the vector meson wave functions. We determine the properties of the gluon density in the proton in both longitudinal and transverse dimensions, including the impact parameter dependent saturation scale. The overall success of the description indicates universality of the emerging gluon distribution and proton shape.
[ { "created": "Tue, 27 Jun 2006 09:00:19 GMT", "version": "v1" }, { "created": "Fri, 29 Sep 2006 11:47:31 GMT", "version": "v2" } ]
2014-11-18
[ [ "Kowalski", "H.", "" ], [ "Motyka", "L.", "" ], [ "Watt", "G.", "" ] ]
We present a simultaneous analysis, within an impact parameter dependent saturated dipole model, of exclusive diffractive vector meson (J/psi, phi and rho) production, deeply virtual Compton scattering and the total gamma* p cross section data measured at HERA. Various cross sections measured as a function of the kinematic variables Q^2, W and t are well described, with little sensitivity to the details of the vector meson wave functions. We determine the properties of the gluon density in the proton in both longitudinal and transverse dimensions, including the impact parameter dependent saturation scale. The overall success of the description indicates universality of the emerging gluon distribution and proton shape.
2309.16615
Kalle Ala-Mattinen
Kalle Ala-Mattinen, Matti Heikinheimo, Kimmo Kainulainen, Kimmo Tuominen
Anatomy of real intermediate state-subtraction scheme
9 pages, 8 figures; Accepted for publication in Phys. Rev. D
null
null
HIP-2023-14/TH
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We study the origin of the real intermediate state subtraction problem and compare its different solutions. We show that the ambiguity in subtraction schemes arises from the on-shell approximation for the 2-point functions that reduces the Schwinger-Dyson equations to the Boltzmann limit. We also suggest a new subtraction scheme which, unlike the earlier definitions, never leads to negative scattering rates. This scheme also quantifies the validity of the on-shell limit in terms of an effective one-particle weight function $R(\Delta )$, where $\Delta$ measures the region around the resonance associated with the real state.
[ { "created": "Thu, 28 Sep 2023 17:14:11 GMT", "version": "v1" }, { "created": "Sun, 19 Nov 2023 21:20:03 GMT", "version": "v2" } ]
2023-11-21
[ [ "Ala-Mattinen", "Kalle", "" ], [ "Heikinheimo", "Matti", "" ], [ "Kainulainen", "Kimmo", "" ], [ "Tuominen", "Kimmo", "" ] ]
We study the origin of the real intermediate state subtraction problem and compare its different solutions. We show that the ambiguity in subtraction schemes arises from the on-shell approximation for the 2-point functions that reduces the Schwinger-Dyson equations to the Boltzmann limit. We also suggest a new subtraction scheme which, unlike the earlier definitions, never leads to negative scattering rates. This scheme also quantifies the validity of the on-shell limit in terms of an effective one-particle weight function $R(\Delta )$, where $\Delta$ measures the region around the resonance associated with the real state.
2207.04215
Etido Inyang
E. P.Inyang, J. E.Ntibi, E. A. Ibanga, and E. S.William
Applicability of Hulthen-Hellmann potential to predict the mass-spectra of heavy mesons via series expansion method
12 Pages,2tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We adopt Hulth\'en plus Hellmann potential as the quark-antiquark interaction potential for predicting the mass spectra of heavy mesons. The adopted potential was made to be temperature-dependent by replacing the screening parameter with Debye mass.The radial Schr\"odinger equation was analytically solved using the series expansion method and energy eigenvalues were obtained. The energy eigenvalues is used to predict the mass spectra of heavy mesons such as charmonium and bottomonium. Four special cases were considered when some of the potential parameters were set to zero, resulting in Hellmann potential, Yukawa potential, Coulomb potential, and Hulth\'en potential, respectively. The present potential provides satisfying results in comparison with experimental data and the work of other researchers with a maximum error of 0.034 GeV.
[ { "created": "Sat, 9 Jul 2022 07:36:23 GMT", "version": "v1" } ]
2022-07-12
[ [ "Inyang", "E. P.", "" ], [ "Ntibi", "J. E.", "" ], [ "Ibanga", "E. A.", "" ], [ "William", "E. S.", "" ] ]
We adopt Hulth\'en plus Hellmann potential as the quark-antiquark interaction potential for predicting the mass spectra of heavy mesons. The adopted potential was made to be temperature-dependent by replacing the screening parameter with Debye mass.The radial Schr\"odinger equation was analytically solved using the series expansion method and energy eigenvalues were obtained. The energy eigenvalues is used to predict the mass spectra of heavy mesons such as charmonium and bottomonium. Four special cases were considered when some of the potential parameters were set to zero, resulting in Hellmann potential, Yukawa potential, Coulomb potential, and Hulth\'en potential, respectively. The present potential provides satisfying results in comparison with experimental data and the work of other researchers with a maximum error of 0.034 GeV.
hep-ph/9311261
Helene Veltman
H. Veltman
Testing the Higgs system at a photon-photon collider
29 pages, report T93/111
Z.Phys. C62 (1994) 235-252
10.1007/BF01560240
null
hep-ph
null
The level of sensitivity of the processes $\gamma\gamma \to ZZ$, $\gamma\gamma \to W^+W^-$ and $\gamma\gamma \to t\bar t$ to the Higgs sector of the Standard Model Lagrangian in the energy region between 200 GeV and 1 TeV is examined. The elementary Higgs boson is taken to have a mass less than 1 TeV. Sizeable effects are found in the $ZZ$ and $t\bar t$ channels if the incoming photons have the same helicity. Also the possibility that the elementary Higgs boson does not exist is examined. Assuming new physics to show up in the TeV energy region the cross sections are evaluated according to the heavy Higgs model. For center of mass energy values close to 1 TeV interesting effects are found in the $t\bar t$ channel if the photons have the same helicity. The limit of large Higgs mass is not unique. The parametrization of this arbitrariness may be interpreted as a representation of the new physics. The effects for the processes $\gamma\gamma\to ZZ$ and $\gamma\gamma\to t\bar t$ are investigated. These effects may be correlated to a possible resonance in $WW$ scattering in the TeV region.
[ { "created": "Wed, 10 Nov 1993 14:25:39 GMT", "version": "v1" } ]
2009-10-22
[ [ "Veltman", "H.", "" ] ]
The level of sensitivity of the processes $\gamma\gamma \to ZZ$, $\gamma\gamma \to W^+W^-$ and $\gamma\gamma \to t\bar t$ to the Higgs sector of the Standard Model Lagrangian in the energy region between 200 GeV and 1 TeV is examined. The elementary Higgs boson is taken to have a mass less than 1 TeV. Sizeable effects are found in the $ZZ$ and $t\bar t$ channels if the incoming photons have the same helicity. Also the possibility that the elementary Higgs boson does not exist is examined. Assuming new physics to show up in the TeV energy region the cross sections are evaluated according to the heavy Higgs model. For center of mass energy values close to 1 TeV interesting effects are found in the $t\bar t$ channel if the photons have the same helicity. The limit of large Higgs mass is not unique. The parametrization of this arbitrariness may be interpreted as a representation of the new physics. The effects for the processes $\gamma\gamma\to ZZ$ and $\gamma\gamma\to t\bar t$ are investigated. These effects may be correlated to a possible resonance in $WW$ scattering in the TeV region.
1304.6051
Holger Frits Bech Nielsen
H. B. Nielsen
Dimension Four Wins the Same Game as the Standard Model Group
After introducing some more review o the previous article the historical stuff was moved into an appendix
Phys. Rev. D 88, 096001 (2013)
10.1103/PhysRevD.88.096001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a previous article Don Bennett and I looked for,found and proposed a game in which the Standard Model group S(U(2)XU(3)) gets singled out as the "winner". Here I propose to extend this "game" to construct a corresponding game between different potential dimensions for space time. The idea is to formulate how the same competition as the one between the potential gauge groups would run out, if restricted to the potential Lorentz or Poincare groups achievable for different dimensions of space time d. The remarkable point is that it is the experimental dimension of space time 4 which wins. So the same function defined over Lie groups seems to single out both the gauge group and the space time dimension in nature. This seems a rather strange coincidence unless there is really some similar physics behind.
[ { "created": "Mon, 22 Apr 2013 18:38:34 GMT", "version": "v1" }, { "created": "Tue, 23 Apr 2013 17:57:18 GMT", "version": "v2" }, { "created": "Mon, 17 Jun 2013 10:06:22 GMT", "version": "v3" }, { "created": "Tue, 18 Jun 2013 17:05:19 GMT", "version": "v4" }, { "created": "Fri, 21 Jun 2013 19:07:04 GMT", "version": "v5" }, { "created": "Mon, 24 Jun 2013 15:45:53 GMT", "version": "v6" }, { "created": "Tue, 17 Sep 2013 14:49:18 GMT", "version": "v7" } ]
2013-11-13
[ [ "Nielsen", "H. B.", "" ] ]
In a previous article Don Bennett and I looked for,found and proposed a game in which the Standard Model group S(U(2)XU(3)) gets singled out as the "winner". Here I propose to extend this "game" to construct a corresponding game between different potential dimensions for space time. The idea is to formulate how the same competition as the one between the potential gauge groups would run out, if restricted to the potential Lorentz or Poincare groups achievable for different dimensions of space time d. The remarkable point is that it is the experimental dimension of space time 4 which wins. So the same function defined over Lie groups seems to single out both the gauge group and the space time dimension in nature. This seems a rather strange coincidence unless there is really some similar physics behind.
hep-ph/0607128
Werner Sauter
M. B. Gay Ducati and W. K. Sauter
Gluon propagator in diffractive scattering
14 pages, 4 figures, accepted for publication in Int. J. Mod. Phys. A (uses ws-ijmpa.cls). Authors corrected
Int.J.Mod.Phys. A21 (2006) 5861-5874
10.1142/S0217751X06033945
null
hep-ph
null
In this work, we perform a comparison of the employ of distinct gluon propagators with the experimental data in diffractive processes, $pp$ elastic scattering and light meson photo-production. The gluon propagators are calculated through non-perturbative methods, being justified their use in this class of events, due to the smallness of the momentum transfer. Our results are not able to select the best choice for the modified gluon propagator among the analyzed ones, showing that the application of this procedure in this class of high energy processes, although giving a reasonable fit to the experimental data, should be taken with same caution.
[ { "created": "Tue, 11 Jul 2006 18:43:21 GMT", "version": "v1" }, { "created": "Wed, 12 Jul 2006 12:37:29 GMT", "version": "v2" } ]
2009-11-11
[ [ "Ducati", "M. B. Gay", "" ], [ "Sauter", "W. K.", "" ] ]
In this work, we perform a comparison of the employ of distinct gluon propagators with the experimental data in diffractive processes, $pp$ elastic scattering and light meson photo-production. The gluon propagators are calculated through non-perturbative methods, being justified their use in this class of events, due to the smallness of the momentum transfer. Our results are not able to select the best choice for the modified gluon propagator among the analyzed ones, showing that the application of this procedure in this class of high energy processes, although giving a reasonable fit to the experimental data, should be taken with same caution.
hep-ph/0304296
Leonid Satarov
I.N. Mishustin (1,2,3), L.M. Satarov (1,2), W. Greiner (1) ((1) Frankfurt Uni., (2) Kurchatov Inst., (3) Niels Bohr Inst.)
How far is normal nuclear matter from the chiral symmetry restoration?
22 pages, 13 figures, dedicated to S.T. Belyaev on the occasion of his 80th birthday
Phys.Rept. 391 (2004) 363-380
10.1016/j.physrep.2003.10.010
null
hep-ph nucl-th
null
Properties of cold nuclear matter are studied within a generalized Nambu-Jona-Lasinio model formulated on the level of constituent nucleons. The model parameters are chosen to reproduce simultaneously the observed nucleon and pion masses in vacuum as well as saturation properties of nuclear matter. The strongest constraints on these parameters are given by the empirical values of the nucleon effective mass and compression modulus at nuclear saturation density. A preferable value of the cut-off momentum, determining density of active quasinucleon states in the Dirac sea, is estimated to about 400 MeV/c. With the most reasonable choice of model parameters we have found a first order phase transition of the liquid-gas type at subsaturation densities and the gradual restoration of chiral symmetry at about 3 times the saturation density. Fluctuations of the scalar condensate around its mean-field value are estimated and shown to be large in the vicinity of chiral transition.
[ { "created": "Wed, 30 Apr 2003 16:13:09 GMT", "version": "v1" } ]
2009-11-10
[ [ "Mishustin", "I. N.", "" ], [ "Satarov", "L. M.", "" ], [ "Greiner", "W.", "" ] ]
Properties of cold nuclear matter are studied within a generalized Nambu-Jona-Lasinio model formulated on the level of constituent nucleons. The model parameters are chosen to reproduce simultaneously the observed nucleon and pion masses in vacuum as well as saturation properties of nuclear matter. The strongest constraints on these parameters are given by the empirical values of the nucleon effective mass and compression modulus at nuclear saturation density. A preferable value of the cut-off momentum, determining density of active quasinucleon states in the Dirac sea, is estimated to about 400 MeV/c. With the most reasonable choice of model parameters we have found a first order phase transition of the liquid-gas type at subsaturation densities and the gradual restoration of chiral symmetry at about 3 times the saturation density. Fluctuations of the scalar condensate around its mean-field value are estimated and shown to be large in the vicinity of chiral transition.
1802.05722
Rahul Srivastava
Salvador Centelles Chuli\'a, Rahul Srivastava, Jos\'e W. F. Valle
Seesaw roadmap to neutrino mass and dark matter
12 pages, 5 figures, published version
Phys. Lett. B, 781 (2018) 122-128
10.1016/j.physletb.2018.03.046
IFIC/18-xxx
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe the many pathways to generate Majorana and Dirac neutrino mass through generalized dimension-5 operators a la Weinberg. The presence of new scalars beyond the Standard Model Higgs doublet implies new possible field contractions, which are required in the case of Dirac neutrinos. We also notice that, in the Dirac neutrino case, the extra symmetries needed to ensure the Dirac nature of neutrinos can also be made responsible for stability of dark matter.
[ { "created": "Thu, 15 Feb 2018 19:00:06 GMT", "version": "v1" }, { "created": "Thu, 3 May 2018 10:10:25 GMT", "version": "v2" } ]
2018-05-04
[ [ "Chuliá", "Salvador Centelles", "" ], [ "Srivastava", "Rahul", "" ], [ "Valle", "José W. F.", "" ] ]
We describe the many pathways to generate Majorana and Dirac neutrino mass through generalized dimension-5 operators a la Weinberg. The presence of new scalars beyond the Standard Model Higgs doublet implies new possible field contractions, which are required in the case of Dirac neutrinos. We also notice that, in the Dirac neutrino case, the extra symmetries needed to ensure the Dirac nature of neutrinos can also be made responsible for stability of dark matter.
1203.5634
Neda Sadooghi
N. Sadooghi and F. Taghinavaz
Local electric current correlation function in an exponentially decaying magnetic field
V1: 16 pages, 7 figures, 2 tables; V2: Section II improved, references added. Version accepted for publication in PRD
Phys. Rev. D85, 125035 (2012)
10.1103/PhysRevD.85.125035
null
hep-ph cond-mat.mes-hall hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effect of an exponentially decaying magnetic field on the dynamics of Dirac fermions in 3+1 dimensions is explored. The spatially decaying magnetic field is assumed to be aligned in the third direction, and is defined by {\mathbf{B}}(x)=B(x){\mathbf{e}}_{z}, with B(x)=B_{0}e^{-\xi\ x/\ell_{B}}. Here, \xi\ is a dimensionless damping factor and \ell_{B}=(eB_{0})^{-1/2} is the magnetic length. As it turns out, the energy spectrum of fermions in this inhomogeneous magnetic field can be analytically determined using the Ritus method. Assuming the magnetic field to be strong, the chiral condensate and the \textit{local} electric current correlation function are computed in the lowest Landau level (LLL) approximation and the results are compared with those arising from a strong homogeneous magnetic field. Although the constant magnetic field B_{0} can be reproduced by taking the limit of \xi-> 0 and/or x-> 0 from B(x), these limits turn out to be singular once the quantum corrections are taken into account.
[ { "created": "Mon, 26 Mar 2012 11:28:47 GMT", "version": "v1" }, { "created": "Mon, 28 May 2012 11:37:00 GMT", "version": "v2" } ]
2013-05-30
[ [ "Sadooghi", "N.", "" ], [ "Taghinavaz", "F.", "" ] ]
The effect of an exponentially decaying magnetic field on the dynamics of Dirac fermions in 3+1 dimensions is explored. The spatially decaying magnetic field is assumed to be aligned in the third direction, and is defined by {\mathbf{B}}(x)=B(x){\mathbf{e}}_{z}, with B(x)=B_{0}e^{-\xi\ x/\ell_{B}}. Here, \xi\ is a dimensionless damping factor and \ell_{B}=(eB_{0})^{-1/2} is the magnetic length. As it turns out, the energy spectrum of fermions in this inhomogeneous magnetic field can be analytically determined using the Ritus method. Assuming the magnetic field to be strong, the chiral condensate and the \textit{local} electric current correlation function are computed in the lowest Landau level (LLL) approximation and the results are compared with those arising from a strong homogeneous magnetic field. Although the constant magnetic field B_{0} can be reproduced by taking the limit of \xi-> 0 and/or x-> 0 from B(x), these limits turn out to be singular once the quantum corrections are taken into account.
2208.01861
Jose Ruiz
Alfredo Gurrola, Jos\'e David Ruiz-\'Alvarez
Quarkophobic W' for LHC searches
FPCP 2022 proceedings
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider a simplified model where a W' boson is added to the standard model with negligible couplings to quarks, but generic couplings to leptons and electroweak bosons. We study the implications of such a model for LHC searches. Consequently, we propose an LHC search through the vector boson fusion topology which would have sensitivity for such a new particle with the current proton-proton collisions's energy and available luminosity.
[ { "created": "Wed, 3 Aug 2022 06:13:34 GMT", "version": "v1" } ]
2022-08-04
[ [ "Gurrola", "Alfredo", "" ], [ "Ruiz-Álvarez", "José David", "" ] ]
We consider a simplified model where a W' boson is added to the standard model with negligible couplings to quarks, but generic couplings to leptons and electroweak bosons. We study the implications of such a model for LHC searches. Consequently, we propose an LHC search through the vector boson fusion topology which would have sensitivity for such a new particle with the current proton-proton collisions's energy and available luminosity.
2211.10620
Sanjib Kumar Agarwalla
Sanjib Kumar Agarwalla, Sudipta Das, Alessio Giarnetti, Davide Meloni, Masoom Singh
Enhancing Sensitivity to Leptonic CP Violation using Complementarity among DUNE, T2HK, and T2HKK
32 pages, 11 figures, 4 tables, and one appendix. A new section 5 added with a new figure 10, a new appendix added with a new figure 11, and more discussions added in the text. This version has the same content as the published article in The European Physical Journal C
null
null
IP/BBSR/2022-08
hep-ph hep-ex physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After the landmark discovery of non-zero $\theta_{13}$ by the modern reactor experiments, unprecedented precision on neutrino mass-mixing parameters has been achieved over the past decade. This has set the stage for the discovery of leptonic CP violation (LCPV) at high confidence level in the next-generation long-baseline neutrino oscillation experiments. In this work, we explore in detail the possible complementarity among the on-axis DUNE and off-axis T2HK experiments to enhance the sensitivity to LCPV suppressing the $\theta_{23}-\delta_{\mathrm{CP}}$ degeneracy. We find that none of these experiments individually can achieve the milestone of 3$\sigma$ LCPV for at least 75% choices of $\delta_{\mathrm{CP}}$ in its entire range of $[-180^{\circ} , 180^{\circ}]$, with their nominal exposures and systematic uncertainties. However, their combination can attain the same for all values of $\theta_{23}$ with only half of their nominal exposures. We observe that the proposed T2HKK setup in combination with DUNE can further increase the CP coverage to more than 80% with only half of their nominal exposures. We study in detail how the coverage in $\delta_{\mathrm{CP}}$ for $\ge$ 3$\sigma$ LCPV depends on the choice of $\theta_{23}$, exposure, optimal runtime in neutrino and antineutrino modes, and systematic uncertainties in these experiments in isolation and combination. We find that with an improved systematic uncertainty of 2.7% in appearance mode, the standalone T2HK setup can provide a CP coverage of around 75% for all values of $\theta_{23}$. We also discuss the pivotal role of intrinsic, extrinsic, and total CP asymmetries in the appearance channel and extrinsic CP asymmetries in the disappearance channel while analyzing our results.
[ { "created": "Sat, 19 Nov 2022 08:41:28 GMT", "version": "v1" }, { "created": "Fri, 11 Aug 2023 18:58:28 GMT", "version": "v2" } ]
2023-08-15
[ [ "Agarwalla", "Sanjib Kumar", "" ], [ "Das", "Sudipta", "" ], [ "Giarnetti", "Alessio", "" ], [ "Meloni", "Davide", "" ], [ "Singh", "Masoom", "" ] ]
After the landmark discovery of non-zero $\theta_{13}$ by the modern reactor experiments, unprecedented precision on neutrino mass-mixing parameters has been achieved over the past decade. This has set the stage for the discovery of leptonic CP violation (LCPV) at high confidence level in the next-generation long-baseline neutrino oscillation experiments. In this work, we explore in detail the possible complementarity among the on-axis DUNE and off-axis T2HK experiments to enhance the sensitivity to LCPV suppressing the $\theta_{23}-\delta_{\mathrm{CP}}$ degeneracy. We find that none of these experiments individually can achieve the milestone of 3$\sigma$ LCPV for at least 75% choices of $\delta_{\mathrm{CP}}$ in its entire range of $[-180^{\circ} , 180^{\circ}]$, with their nominal exposures and systematic uncertainties. However, their combination can attain the same for all values of $\theta_{23}$ with only half of their nominal exposures. We observe that the proposed T2HKK setup in combination with DUNE can further increase the CP coverage to more than 80% with only half of their nominal exposures. We study in detail how the coverage in $\delta_{\mathrm{CP}}$ for $\ge$ 3$\sigma$ LCPV depends on the choice of $\theta_{23}$, exposure, optimal runtime in neutrino and antineutrino modes, and systematic uncertainties in these experiments in isolation and combination. We find that with an improved systematic uncertainty of 2.7% in appearance mode, the standalone T2HK setup can provide a CP coverage of around 75% for all values of $\theta_{23}$. We also discuss the pivotal role of intrinsic, extrinsic, and total CP asymmetries in the appearance channel and extrinsic CP asymmetries in the disappearance channel while analyzing our results.
1310.1962
Keita Fukushima
Keita Fukushima
Dipole Moment Bounds on Scalar Dark Matter Annihilation
Presentation at the DPF 2013 Meeting of the American Physical Society Division of Particles and Fields, Santa Cruz, California, August 13-17, 2013
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a scalar dark matter annihilations to light leptons mediated by charged exotic fermions. The interaction of this model also adds a correction to dipole moments of light leptons. In the simplified model, these processes will depend upon the same coupling constants. The tight experimental bounds on the dipole moments of light leptons will constrain the coupling constants. Consequently, this bound will then limit the annihilations. We will produce this dipole moment bounds on the annihilation. From this analysis, we report that the bound on annihilation to the electrons is $4.0\times10^{-7}\pb$ (g-2) + $8.8\times 10^{-15}\pb$ (EDM) and the muons is $5.6\times 10^{-4}\pb$ (g-2) + $180\pb$ (EDM), in the limit where the mediator is much heavier than dark matter. The parentheses indicate the dipole moment used to obtain the values. We note that only the annihilation to muons through a CP-violating (EDM) coupling is not excluded from indirect detection experiments.
[ { "created": "Mon, 7 Oct 2013 21:57:46 GMT", "version": "v1" } ]
2013-10-09
[ [ "Fukushima", "Keita", "" ] ]
We consider a scalar dark matter annihilations to light leptons mediated by charged exotic fermions. The interaction of this model also adds a correction to dipole moments of light leptons. In the simplified model, these processes will depend upon the same coupling constants. The tight experimental bounds on the dipole moments of light leptons will constrain the coupling constants. Consequently, this bound will then limit the annihilations. We will produce this dipole moment bounds on the annihilation. From this analysis, we report that the bound on annihilation to the electrons is $4.0\times10^{-7}\pb$ (g-2) + $8.8\times 10^{-15}\pb$ (EDM) and the muons is $5.6\times 10^{-4}\pb$ (g-2) + $180\pb$ (EDM), in the limit where the mediator is much heavier than dark matter. The parentheses indicate the dipole moment used to obtain the values. We note that only the annihilation to muons through a CP-violating (EDM) coupling is not excluded from indirect detection experiments.
2211.12960
Chia-Wei Liu
Chia-Wei Liu and Chao-Qiang Geng
Nonleptonic decays of $\Xi_{cc}\to \Xi_c \pi$ with $\Xi_c-\Xi_c'$ mixing
17 pages, 1 figure, accepted by Physical Review D
null
10.1103/PhysRevD.107.013006
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Aiming on testing the $\Xi_c-\Xi_c'$ mixing, we study the decays of $\Xi_{cc}\to \Xi_c \pi$ with $\Xi_{cc} = (\Xi_{cc}^{++} , \Xi_{cc} ^+ )$, $\Xi_c = (\Xi_c^{(\prime)+},\Xi_c^{(\prime)0})$ and $\pi = (\pi^+ , \pi^0)$. The soft-meson limit is considered along with the pole model, and the baryon matrix elements are evaluated by the bag model with and without removing the center-of-mass motion (CMM). We find that the four-quark operator matrix elements are about twice larger once the unwanted CMM is removed. We obtain that ${\cal R} = {\cal B}(\Xi_{cc}^+ \to \Xi_c^{\prime +} \pi^+ )/ {\cal B}(\Xi_{cc}^+ \to \Xi_c^{ +} \pi^+ ) = 0.87^{+0.17}_{-0.11} $ and $1.45$ with and without removing the CMM, where the former is close to the lower bound and the later is well consistent with ${\cal R} = 1.41 \pm 0.17 \pm 0.10$ measured at LHCb. In addition, we show that after including the mixing, the up-down asymmetry of $\alpha( \Xi_{cc}^+ \to \Xi_c^{(\prime)0 } \pi^+)$ flips sign. Explicitly, we obtain that $\alpha(\Xi_{cc}^{+} \to \Xi_c^{\prime +} \pi^0) = 0.52$ and $\alpha(\Xi_{cc}^{+} \to \Xi_c^{ 0 } \pi^+) = 0.31$ with and without the CMM corrections, respectively, which are all negative if the mixing is absence. As a bonus, a positive value of $\alpha(\Xi_{cc}^{+} \to \Xi_c^{\prime 0} \pi^+)$ in experiments can also serve as the evidence of the $W$-exchange contributions.
[ { "created": "Wed, 23 Nov 2022 14:06:03 GMT", "version": "v1" }, { "created": "Wed, 25 Jan 2023 15:35:14 GMT", "version": "v2" } ]
2023-01-26
[ [ "Liu", "Chia-Wei", "" ], [ "Geng", "Chao-Qiang", "" ] ]
Aiming on testing the $\Xi_c-\Xi_c'$ mixing, we study the decays of $\Xi_{cc}\to \Xi_c \pi$ with $\Xi_{cc} = (\Xi_{cc}^{++} , \Xi_{cc} ^+ )$, $\Xi_c = (\Xi_c^{(\prime)+},\Xi_c^{(\prime)0})$ and $\pi = (\pi^+ , \pi^0)$. The soft-meson limit is considered along with the pole model, and the baryon matrix elements are evaluated by the bag model with and without removing the center-of-mass motion (CMM). We find that the four-quark operator matrix elements are about twice larger once the unwanted CMM is removed. We obtain that ${\cal R} = {\cal B}(\Xi_{cc}^+ \to \Xi_c^{\prime +} \pi^+ )/ {\cal B}(\Xi_{cc}^+ \to \Xi_c^{ +} \pi^+ ) = 0.87^{+0.17}_{-0.11} $ and $1.45$ with and without removing the CMM, where the former is close to the lower bound and the later is well consistent with ${\cal R} = 1.41 \pm 0.17 \pm 0.10$ measured at LHCb. In addition, we show that after including the mixing, the up-down asymmetry of $\alpha( \Xi_{cc}^+ \to \Xi_c^{(\prime)0 } \pi^+)$ flips sign. Explicitly, we obtain that $\alpha(\Xi_{cc}^{+} \to \Xi_c^{\prime +} \pi^0) = 0.52$ and $\alpha(\Xi_{cc}^{+} \to \Xi_c^{ 0 } \pi^+) = 0.31$ with and without the CMM corrections, respectively, which are all negative if the mixing is absence. As a bonus, a positive value of $\alpha(\Xi_{cc}^{+} \to \Xi_c^{\prime 0} \pi^+)$ in experiments can also serve as the evidence of the $W$-exchange contributions.
hep-ph/9708492
Katri Huitu
K. Huitu, P.N. Pandita and K. Puolam\"aki
Constraining the scales of supersymmetric left-right models
5 pages, Latex, talk given in Beyond the Standard Model V in Balholm, Norway
null
10.1063/1.54501
HIP-1997-41/TH
hep-ph
null
We'll review our study of the constraints on the scales in the supersymmetric left-right model (SUSYLR). The conservation of color and electromagnetism in the ground state of the theory implies a relation between right-handed gauge boson mass and soft squark mass. Furthermore, in general for heavy $W_R$, $\tan\alpha$ is larger than one, and the right-handed sneutrino VEV, responsible for spontaneous R-parity breaking, is at most of the order $M_{SUSY}/h_{\Delta_R}$, where $M_{SUSY}$ is supersymmetry breaking scale and $h_{\Delta_R}$ is the Yukawa coupling in Majorana mass term for right-handed neutrinos.
[ { "created": "Fri, 29 Aug 1997 11:48:13 GMT", "version": "v1" } ]
2009-10-30
[ [ "Huitu", "K.", "" ], [ "Pandita", "P. N.", "" ], [ "Puolamäki", "K.", "" ] ]
We'll review our study of the constraints on the scales in the supersymmetric left-right model (SUSYLR). The conservation of color and electromagnetism in the ground state of the theory implies a relation between right-handed gauge boson mass and soft squark mass. Furthermore, in general for heavy $W_R$, $\tan\alpha$ is larger than one, and the right-handed sneutrino VEV, responsible for spontaneous R-parity breaking, is at most of the order $M_{SUSY}/h_{\Delta_R}$, where $M_{SUSY}$ is supersymmetry breaking scale and $h_{\Delta_R}$ is the Yukawa coupling in Majorana mass term for right-handed neutrinos.
1004.3297
Howard Baer
Howard Baer, Radovan Dermisek, Shibi Rajagopalan, Heaya Summy
Neutralino, axion and axino cold dark matter in minimal, hypercharged and gaugino AMSB
29 pages including 13 figures
JCAP 1007:014,2010
10.1088/1475-7516/2010/07/014
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetric models based on anomaly-mediated SUSY breaking (AMSB) generally give rise to a neutral wino as a WIMP cold dark matter (CDM) candidate, whose thermal abundance is well below measured values. Here, we investigate four scenarios to reconcile AMSB dark matter with the measured abundance: 1. non-thermal wino production due to decays of scalar fields ({\it e.g} moduli), 2. non-thermal wino production due to decays of gravitinos, 3. non-thermal wino production due to heavy axino decays, and 4. the case of an axino LSP, where the bulk of CDM is made up of axions and thermally produced axinos. In cases 1 and 2, we expect wino CDM to constitute the entire measured DM abundance, and we investigate wino-like WIMP direct and indirect detection rates. Wino direct detection rates can be large, and more importantly, are bounded from below, so that ton-scale noble liquid detectors should access all of parameter space for m_{\tz_1}\alt 500 GeV. Indirect wino detection rates via neutrino telescopes and space-based cosmic ray detectors can also be large. In case 3, the DM would consist of an axion plus wino admixture, whose exact proportions are very model dependent. In this case, it is possible that both an axion and a wino-like WIMP could be detected experimentally. In case 4., we calculate the re-heat temperature of the universe after inflation. In this case, no direct or indirect WIMP signals should be seen, although direct detection of relic axions may be possible. For each DM scenario, we show results for the minimal AMSB model, as well as for the hypercharged and gaugino AMSB models.
[ { "created": "Mon, 19 Apr 2010 20:19:01 GMT", "version": "v1" }, { "created": "Fri, 18 Jun 2010 10:31:31 GMT", "version": "v2" } ]
2014-11-20
[ [ "Baer", "Howard", "" ], [ "Dermisek", "Radovan", "" ], [ "Rajagopalan", "Shibi", "" ], [ "Summy", "Heaya", "" ] ]
Supersymmetric models based on anomaly-mediated SUSY breaking (AMSB) generally give rise to a neutral wino as a WIMP cold dark matter (CDM) candidate, whose thermal abundance is well below measured values. Here, we investigate four scenarios to reconcile AMSB dark matter with the measured abundance: 1. non-thermal wino production due to decays of scalar fields ({\it e.g} moduli), 2. non-thermal wino production due to decays of gravitinos, 3. non-thermal wino production due to heavy axino decays, and 4. the case of an axino LSP, where the bulk of CDM is made up of axions and thermally produced axinos. In cases 1 and 2, we expect wino CDM to constitute the entire measured DM abundance, and we investigate wino-like WIMP direct and indirect detection rates. Wino direct detection rates can be large, and more importantly, are bounded from below, so that ton-scale noble liquid detectors should access all of parameter space for m_{\tz_1}\alt 500 GeV. Indirect wino detection rates via neutrino telescopes and space-based cosmic ray detectors can also be large. In case 3, the DM would consist of an axion plus wino admixture, whose exact proportions are very model dependent. In this case, it is possible that both an axion and a wino-like WIMP could be detected experimentally. In case 4., we calculate the re-heat temperature of the universe after inflation. In this case, no direct or indirect WIMP signals should be seen, although direct detection of relic axions may be possible. For each DM scenario, we show results for the minimal AMSB model, as well as for the hypercharged and gaugino AMSB models.
hep-ph/9912402
Eugene Levin
Eugene Levin (Tel Aviv U. /BNL)
Cost of Survival for Large Rapidity Gaps
4 pages, 3 figures
null
null
BNL-NT-99/10, TAUP -2614-99
hep-ph
null
In this talk, given at "RunII QCD and weak boson WS", we report on calculations of the survival probability of the large rapidity gap (LRG) processes and its energy behaviour.
[ { "created": "Fri, 17 Dec 1999 14:36:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Levin", "Eugene", "", "Tel Aviv U. /BNL" ] ]
In this talk, given at "RunII QCD and weak boson WS", we report on calculations of the survival probability of the large rapidity gap (LRG) processes and its energy behaviour.
hep-ph/0305285
Stephen Godfrey
F.E. Close (Oxford) and S. Godfrey (Carleton University, CSSM Adelaide, and TRIUMF)
Charmonium Hybrid Production in Exclusive B Meson Decays
references added and some of the text rewritten so it is clearer
Phys.Lett. B574 (2003) 210-216
10.1016/j.physletb.2003.09.011
ADP-03-120/T558, TRI-PP-03-04, OUTP-03-13-P
hep-ph hep-ex
null
Recent data on charmonium production in B-meson decays suggest that charmonium hybrid mesons with mass ~4 GeV may be produced in B-decay via c\bar{c} colour octet operators. Some of these states are likely to be narrow with clean signatures to J/\psi pi^+ pi^- final states. Experimental signatures and search strategies for existing B-factories are described.
[ { "created": "Mon, 26 May 2003 02:19:33 GMT", "version": "v1" }, { "created": "Tue, 12 Aug 2003 21:37:57 GMT", "version": "v2" } ]
2015-06-25
[ [ "Close", "F. E.", "", "Oxford" ], [ "Godfrey", "S.", "", "Carleton University, CSSM\n Adelaide, and TRIUMF" ] ]
Recent data on charmonium production in B-meson decays suggest that charmonium hybrid mesons with mass ~4 GeV may be produced in B-decay via c\bar{c} colour octet operators. Some of these states are likely to be narrow with clean signatures to J/\psi pi^+ pi^- final states. Experimental signatures and search strategies for existing B-factories are described.
1403.1001
Roman Nevzorov
C.D. Froggatt, R. Nevzorov, H.B. Nielsen, A.W. Thomas
Cosmological constant in SUGRA models with Planck scale SUSY breaking and degenerate vacua
12 pages, 1 figure, version of the paper published in PLB
Phys.Lett. B 737 (2014) 167-171
10.1016/j.physletb.2014.08.027
ADP-14-8/T866
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The empirical mass of the Higgs boson suggests small to vanishing values of the quartic Higgs self--coupling and the corresponding beta function at the Planck scale, leading to degenerate vacua. This leads us to suggest that the measured value of the cosmological constant can originate from supergravity (SUGRA) models with degenerate vacua. This scenario is realised if there are at least three exactly degenerate vacua. In the first vacuum, associated with the physical one, local supersymmetry (SUSY) is broken near the Planck scale while the breakdown of the SU(2)_W\times U(1)_Y symmetry takes place at the electroweak (EW) scale. In the second vacuum local SUSY breaking is induced by gaugino condensation at a scale which is just slightly lower than \Lambda_{QCD} in the physical vacuum. Finally, in the third vacuum local SUSY and EW symmetry are broken near the Planck scale.
[ { "created": "Wed, 5 Mar 2014 04:30:45 GMT", "version": "v1" }, { "created": "Wed, 8 Oct 2014 12:32:35 GMT", "version": "v2" } ]
2015-06-19
[ [ "Froggatt", "C. D.", "" ], [ "Nevzorov", "R.", "" ], [ "Nielsen", "H. B.", "" ], [ "Thomas", "A. W.", "" ] ]
The empirical mass of the Higgs boson suggests small to vanishing values of the quartic Higgs self--coupling and the corresponding beta function at the Planck scale, leading to degenerate vacua. This leads us to suggest that the measured value of the cosmological constant can originate from supergravity (SUGRA) models with degenerate vacua. This scenario is realised if there are at least three exactly degenerate vacua. In the first vacuum, associated with the physical one, local supersymmetry (SUSY) is broken near the Planck scale while the breakdown of the SU(2)_W\times U(1)_Y symmetry takes place at the electroweak (EW) scale. In the second vacuum local SUSY breaking is induced by gaugino condensation at a scale which is just slightly lower than \Lambda_{QCD} in the physical vacuum. Finally, in the third vacuum local SUSY and EW symmetry are broken near the Planck scale.
hep-ph/9509239
Davison Soper
Arjun Berera and Davison E. Soper
Behavior of Diffractive Parton Distribution Functions
35 pages, REVTEX, uses epsf.tex to insert figures; with 11 figures in encapsulated postscript form, which epsf.tex will insert
Phys.Rev.D53:6162-6179,1996
10.1103/PhysRevD.53.6162
PSU/TH/163 and OITS 581
hep-ph
null
Diffractive parton distribution functions give the probability to find a parton in a hadron if the hadron is diffractively scattered. We provide an operator definition of these functions and discuss their relation to diffractive deeply inelastic scattering and to photoproduction of jets at HERA. We perform a calculation in the style of ``constituent counting rules'' for the behavior of these functions when the detected parton carries almost all of the longitudinal momentum transferred from the scattered hadron.
[ { "created": "Wed, 6 Sep 1995 19:47:17 GMT", "version": "v1" } ]
2014-11-17
[ [ "Berera", "Arjun", "" ], [ "Soper", "Davison E.", "" ] ]
Diffractive parton distribution functions give the probability to find a parton in a hadron if the hadron is diffractively scattered. We provide an operator definition of these functions and discuss their relation to diffractive deeply inelastic scattering and to photoproduction of jets at HERA. We perform a calculation in the style of ``constituent counting rules'' for the behavior of these functions when the detected parton carries almost all of the longitudinal momentum transferred from the scattered hadron.
0707.3366
Santiago Noguera
A. Courtoy, S. Noguera
The Pion-Photon Transition Distribution Amplitudes in the Nambu-Jona Lasinio Model
14 pag. and 6 fig, final version (to appear in Phys. Rev. D)
Phys.Rev.D76:094026,2007
10.1103/PhysRevD.76.094026
null
hep-ph
null
We define the pion-photon Transition Distribution Amplitudes (TDA) in a field theoretic formalism from a covariant Bethe-Salpeter approach for the determination of the bound state. We apply our formalism to the Nambu - Jona Lasinio model, as a realistic theory of the pion. The obtained vector and axial TDAs satisfy all features required by general considerations. In particular, sum rules and polynomiality condition are explicitly verified. We have numerically proved that the odd coefficients in the polynomiality expansion of the vector TDA vanish in the chiral limit. The role of PCAC and the presence of a pion pole are explicitly shown.
[ { "created": "Mon, 23 Jul 2007 12:49:48 GMT", "version": "v1" }, { "created": "Thu, 18 Oct 2007 10:03:19 GMT", "version": "v2" }, { "created": "Thu, 29 Nov 2007 12:53:36 GMT", "version": "v3" } ]
2008-11-26
[ [ "Courtoy", "A.", "" ], [ "Noguera", "S.", "" ] ]
We define the pion-photon Transition Distribution Amplitudes (TDA) in a field theoretic formalism from a covariant Bethe-Salpeter approach for the determination of the bound state. We apply our formalism to the Nambu - Jona Lasinio model, as a realistic theory of the pion. The obtained vector and axial TDAs satisfy all features required by general considerations. In particular, sum rules and polynomiality condition are explicitly verified. We have numerically proved that the odd coefficients in the polynomiality expansion of the vector TDA vanish in the chiral limit. The role of PCAC and the presence of a pion pole are explicitly shown.
1605.06606
Vadim Guzey
M. Alvioli (Perugia U.), L. Frankfurt (Tel Aviv U. and Penn State U.), V. Guzey (PNPI), M. Strikman (Penn State U.), and M. Zhalov (PNPI)
Mapping color fluctuations in the photon in ultraperipheral heavy ion collisions at the Large Hadron Collider
11 pages, 4 figures. Matches the final published version
Phys. Lett. B767 (2017) 450-457
10.1016/j.physletb.2017.02.034
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We model effects of color fluctuations (CFs) in the light-cone photon wave function and for the first time make predictions for the distribution over the number of wounded nucleons $\nu$ in the inelastic photon-nucleus scattering. We show that CFs lead to a dramatic enhancement of this distribution at $\nu=1$ and large $\nu > 10$. We also study the implications of different scales and CFs in the photon wave function on the total transverse energy $\Sigma E_T$ and other observables in inelastic $\gamma A$ scattering with different triggers. Our predictions can be tested in proton-nucleus and nucleus-nucleus ultraperipheral collisions at the LHC and will help to map CFs, whose first indications have already been observed at the LHC.
[ { "created": "Sat, 21 May 2016 08:42:22 GMT", "version": "v1" }, { "created": "Wed, 15 Mar 2017 08:34:17 GMT", "version": "v2" } ]
2017-03-16
[ [ "Alvioli", "M.", "", "Perugia U." ], [ "Frankfurt", "L.", "", "Tel Aviv U. and Penn State U." ], [ "Guzey", "V.", "", "PNPI" ], [ "Strikman", "M.", "", "Penn State U." ], [ "Zhalov", "M.", "", "PNPI" ] ]
We model effects of color fluctuations (CFs) in the light-cone photon wave function and for the first time make predictions for the distribution over the number of wounded nucleons $\nu$ in the inelastic photon-nucleus scattering. We show that CFs lead to a dramatic enhancement of this distribution at $\nu=1$ and large $\nu > 10$. We also study the implications of different scales and CFs in the photon wave function on the total transverse energy $\Sigma E_T$ and other observables in inelastic $\gamma A$ scattering with different triggers. Our predictions can be tested in proton-nucleus and nucleus-nucleus ultraperipheral collisions at the LHC and will help to map CFs, whose first indications have already been observed at the LHC.
hep-ph/0104192
M. V. T. Machado
M.B. Gay Ducati, M.V.T. Machado (UFRGS)
Truncated BFKL Series in Electron-Proton Collisions
23 pages, 13 figures, uses jhep.cls
null
null
null
hep-ph
null
We study the contribution of the truncated BFKL series to the electroproduction process showing that a reliable description is obtained taking into account two orders in perturbation theory. Using the recent F2 logarithmic slope data as a constraint to the adustable parameters, the inclusive structure function is described in a wide range of the small x HERA kinematical region, consistent with the unitarity bound. We also extrapolate the extimates to the THERA region.
[ { "created": "Thu, 19 Apr 2001 14:01:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ducati", "M. B. Gay", "", "UFRGS" ], [ "Machado", "M. V. T.", "", "UFRGS" ] ]
We study the contribution of the truncated BFKL series to the electroproduction process showing that a reliable description is obtained taking into account two orders in perturbation theory. Using the recent F2 logarithmic slope data as a constraint to the adustable parameters, the inclusive structure function is described in a wide range of the small x HERA kinematical region, consistent with the unitarity bound. We also extrapolate the extimates to the THERA region.
1609.00208
Edward Hardy
Edward Hardy
Miniclusters in the Axiverse
19 pages, 7 figures, JHEP version
null
10.1007/JHEP02(2017)046
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If dark matter is an axion-like-particle a significant fraction of the present day relic abundance could be concentrated in compact gravitationally bound miniclusters. We study the minicluster masses compatible with the dark matter relic density constraint. If they form from fluctuations produced by PQ symmetry breaking, minicluster masses up to hundreds of solar masses are possible, although over most of the parameter space they are much lighter. The size of these objects is typically within a few orders of magnitude of an astronomical unit. We also show that miniclusters can form if an axion gets mass from a hidden sector with a first order phase transition that takes a relatively long time to complete. Therefore they can appear in models where PQ symmetry is broken before inflation, compatible with large axion decay constants and string theory UV completions.
[ { "created": "Thu, 1 Sep 2016 12:15:58 GMT", "version": "v1" }, { "created": "Wed, 8 Feb 2017 15:06:07 GMT", "version": "v2" } ]
2017-03-08
[ [ "Hardy", "Edward", "" ] ]
If dark matter is an axion-like-particle a significant fraction of the present day relic abundance could be concentrated in compact gravitationally bound miniclusters. We study the minicluster masses compatible with the dark matter relic density constraint. If they form from fluctuations produced by PQ symmetry breaking, minicluster masses up to hundreds of solar masses are possible, although over most of the parameter space they are much lighter. The size of these objects is typically within a few orders of magnitude of an astronomical unit. We also show that miniclusters can form if an axion gets mass from a hidden sector with a first order phase transition that takes a relatively long time to complete. Therefore they can appear in models where PQ symmetry is broken before inflation, compatible with large axion decay constants and string theory UV completions.
hep-ph/0312090
Christoph Bobeth
Christoph Bobeth, Paolo Gambino, Martin Gorbahn, and Ulrich Haisch
Complete NNLO QCD Analysis of B -> X_s l^+ l^- and Higher Order Electroweak Effects
26 pages, 7 figures; v5: corrected normalisation in Eq. (5), numerical results unchanged
JHEP 0404 (2004) 071
10.1088/1126-6708/2004/04/071
CERN-TH-2003-260; TUM-HEP-532-03; FERMILAB-PUB-03-046-T; UCSD-PTH-03-19; IPPP-03-77
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We complete the next-to-next-to-leading order QCD calculation of the branching ratio for B -> X_s l^+ l^- including recent results for the three-loop anomalous dimension matrix and two-loop matrix elements. These new contributions modify the branching ratio in the low-q^2 region, BR_ll, by about +1% and -4%, respectively. We furthermore discuss the appropriate normalization of the electromagnetic coupling alpha and calculate the dominant higher order electroweak effects, showing that, due to accidental cancellations, they change BR_ll by only -1.5% if alpha(mu) is normalized at mu = O(m_b), while they shift it by about -8.5% if one uses a high scale normalization mu = O(M_W). The position of the zero of the forward-backward asymmetry, q_0^2, is changed by around +2%. After introducing a few additional improvements in order to reduce the theoretical error, we perform a comprehensive study of the uncertainty. We obtain BR_ll(1 GeV^2 <= q^2 <= 6 GeV^2) = (1.57 +- 0.16) x 10^-6 and q_0^2 = (3.76 +- 0.33) GeV^2 and note that the part of the uncertainty due to the b-quark mass can be easily reduced.
[ { "created": "Fri, 5 Dec 2003 20:44:45 GMT", "version": "v1" }, { "created": "Sun, 7 Dec 2003 02:25:05 GMT", "version": "v2" }, { "created": "Fri, 19 Mar 2004 17:09:14 GMT", "version": "v3" }, { "created": "Mon, 24 Oct 2005 19:54:35 GMT", "version": "v4" }, { "created": "Sun, 16 Oct 2011 19:12:40 GMT", "version": "v5" } ]
2011-10-18
[ [ "Bobeth", "Christoph", "" ], [ "Gambino", "Paolo", "" ], [ "Gorbahn", "Martin", "" ], [ "Haisch", "Ulrich", "" ] ]
We complete the next-to-next-to-leading order QCD calculation of the branching ratio for B -> X_s l^+ l^- including recent results for the three-loop anomalous dimension matrix and two-loop matrix elements. These new contributions modify the branching ratio in the low-q^2 region, BR_ll, by about +1% and -4%, respectively. We furthermore discuss the appropriate normalization of the electromagnetic coupling alpha and calculate the dominant higher order electroweak effects, showing that, due to accidental cancellations, they change BR_ll by only -1.5% if alpha(mu) is normalized at mu = O(m_b), while they shift it by about -8.5% if one uses a high scale normalization mu = O(M_W). The position of the zero of the forward-backward asymmetry, q_0^2, is changed by around +2%. After introducing a few additional improvements in order to reduce the theoretical error, we perform a comprehensive study of the uncertainty. We obtain BR_ll(1 GeV^2 <= q^2 <= 6 GeV^2) = (1.57 +- 0.16) x 10^-6 and q_0^2 = (3.76 +- 0.33) GeV^2 and note that the part of the uncertainty due to the b-quark mass can be easily reduced.
hep-ph/0210312
Joannis Papavassiliou
J. Papavassiliou, J. Bernabeu, and J. Vidal
On the definition and observability of the neutrino charge radius
5 pages, no figures, talk presented at the XXX International Meeting on Fundamental Physics, IMFP2002, Jaca (Huesca), January 28th -- February 1st, 2002
Nucl.Phys.Proc.Suppl. 114 (2003) 197-201
10.1016/S0920-5632(02)01905-9
FTUV-02-1023
hep-ph
null
We present a brief summary of recent results concerning the unambiguous definition and experimental extraction of the gauge-invariant and process-independent neutrino charge radius.
[ { "created": "Wed, 23 Oct 2002 12:51:29 GMT", "version": "v1" } ]
2009-11-07
[ [ "Papavassiliou", "J.", "" ], [ "Bernabeu", "J.", "" ], [ "Vidal", "J.", "" ] ]
We present a brief summary of recent results concerning the unambiguous definition and experimental extraction of the gauge-invariant and process-independent neutrino charge radius.
1104.2919
Edison Franco
Edison T. Franco
Question for SU(5) x SU(5) string unification
13 pages, 9 figures. References updated and typos corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Here we ask if it is possible to have string unification in $\mathsf{SU(5)\times SU(5)}$ gauge group. We specifically investigate the weakly coupled heterotic string unification for the four couplings in this framework. We show that only a limited versions of $\mathsf{SU(5)\times SU(5)}$ with adjoint representation components at intermediated scales, between $M_Z$ and $\Lambda$ (unification), are allowed. This is essentially due to the limitation in the parameter space to the gauge coupling constant $\alpha_1^{-1}$ related to hypercharge. Indeed, only the vanishing hypercharge decompositions of $\mathsf{SU(5)_L}$ subgroup can help to this unification, namely, the fermion and boson triplets, $\Sigma_3\sim(1,3)_0$, and the fermion and boson octets, $\Sigma_8\sim(8,1)_0$. Thus, these intermediate particles are compatible with the so-called Adjoint $\mathsf{SU(5)}$. The triplets must live in TeV region and could be accessible at colliders while the octets must alive in very high energy scales. We also show that the non-SUSY unification scenario requires the introduction of an additional $\mathsf{SU(2)_L}$ scalar color triplet, $\eta \sim (3,3)_{-{1}/{3}}$, at relatively low energies ($\sim 10^{5-11}$GeV), and it may induce the proton decay.
[ { "created": "Thu, 14 Apr 2011 20:26:11 GMT", "version": "v1" }, { "created": "Sun, 24 Apr 2011 21:01:32 GMT", "version": "v2" }, { "created": "Sun, 12 Mar 2017 09:56:28 GMT", "version": "v3" } ]
2017-03-14
[ [ "Franco", "Edison T.", "" ] ]
Here we ask if it is possible to have string unification in $\mathsf{SU(5)\times SU(5)}$ gauge group. We specifically investigate the weakly coupled heterotic string unification for the four couplings in this framework. We show that only a limited versions of $\mathsf{SU(5)\times SU(5)}$ with adjoint representation components at intermediated scales, between $M_Z$ and $\Lambda$ (unification), are allowed. This is essentially due to the limitation in the parameter space to the gauge coupling constant $\alpha_1^{-1}$ related to hypercharge. Indeed, only the vanishing hypercharge decompositions of $\mathsf{SU(5)_L}$ subgroup can help to this unification, namely, the fermion and boson triplets, $\Sigma_3\sim(1,3)_0$, and the fermion and boson octets, $\Sigma_8\sim(8,1)_0$. Thus, these intermediate particles are compatible with the so-called Adjoint $\mathsf{SU(5)}$. The triplets must live in TeV region and could be accessible at colliders while the octets must alive in very high energy scales. We also show that the non-SUSY unification scenario requires the introduction of an additional $\mathsf{SU(2)_L}$ scalar color triplet, $\eta \sim (3,3)_{-{1}/{3}}$, at relatively low energies ($\sim 10^{5-11}$GeV), and it may induce the proton decay.
1310.1770
S. V. Troitsky
S.V. Troitsky and V.E. Troitsky
Transition from a relativistic constituent-quark model to the quantum-chromodynamical asymptotics: a quantitative description of the pion electromagnetic form factor at intermediate values of the momentum transfer
7 pages, RevTex 4.1, 5 figures. V2: a reference added, minor textual changes, version accepted by Phys. Rev. D
Phys. Rev. D 88, 093005 (2013)
10.1103/PhysRevD.88.093005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We adopt a non-perturbative relativistic constituent-quark model for the pi-meson electromagnetic form factor, which have successfully predicted experimental results, and supplement it with the effective momentum-dependent quark mass to study quantitatively the transition to the perturbative QCD asymptotics. The required asymptotical behaviour (including both the Q^{-2} fall-off and the correct coefficient) settles down automatically when the quark mass is switched off; however, the present experimental data on the form factor suggest that this cannot happen at the values of the momentum transfer below ~10 GeV^2. The effective constituent-quark mass below this scale acquires substantial non-perturbative contributions.
[ { "created": "Mon, 7 Oct 2013 13:13:46 GMT", "version": "v1" }, { "created": "Mon, 11 Nov 2013 07:16:05 GMT", "version": "v2" } ]
2013-11-19
[ [ "Troitsky", "S. V.", "" ], [ "Troitsky", "V. E.", "" ] ]
We adopt a non-perturbative relativistic constituent-quark model for the pi-meson electromagnetic form factor, which have successfully predicted experimental results, and supplement it with the effective momentum-dependent quark mass to study quantitatively the transition to the perturbative QCD asymptotics. The required asymptotical behaviour (including both the Q^{-2} fall-off and the correct coefficient) settles down automatically when the quark mass is switched off; however, the present experimental data on the form factor suggest that this cannot happen at the values of the momentum transfer below ~10 GeV^2. The effective constituent-quark mass below this scale acquires substantial non-perturbative contributions.
1009.6137
Antonio Vairo
Antonio Vairo
Quarkonium in a weakly-coupled quark-gluon plasma
9 pages, 2 figures; contribution to QCD@Work 2010, Martina Franca, June 20-23, 2010
AIP Conf.Proc.1317:241-249,2011
10.1063/1.3536565
TUM-EFT 13/10
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report about a recent calculation of the heavy quarkonium mass and decay width in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> pi T >> m alpha_s^2 >> m_D, m being the heavy-quark mass, up to order m alpha_s^5. The calculation may be relevant to understand the behavior of the Y(1S) in a quark-gluon plasma at present-day colliders.
[ { "created": "Thu, 30 Sep 2010 13:58:22 GMT", "version": "v1" } ]
2011-02-01
[ [ "Vairo", "Antonio", "" ] ]
We report about a recent calculation of the heavy quarkonium mass and decay width in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> pi T >> m alpha_s^2 >> m_D, m being the heavy-quark mass, up to order m alpha_s^5. The calculation may be relevant to understand the behavior of the Y(1S) in a quark-gluon plasma at present-day colliders.
hep-ph/0111268
Antonio Lopez Maroto
Antonio L. Maroto
Cosmological magnetic fields induced by metric perturbations after inflation
8 pages, 1 figure. Presented at COSMO-01 conference, Rovaniemi, Finland, August 29-September 4, 2001
null
null
null
hep-ph
null
We consider the amplification of electromagnetic quantum vacuum fluctuations induced by the presence of metric perturbations at the end of inflation. We obtain the amplitude of the corresponding magnetic fields on super-Hubble scales and compare it with the requirements of the galactic dynamo mechanism for different values of the spectral index. Finally we discuss the possible effects of the dissipation of such fields in the form of gravitational waves.
[ { "created": "Wed, 21 Nov 2001 20:35:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Maroto", "Antonio L.", "" ] ]
We consider the amplification of electromagnetic quantum vacuum fluctuations induced by the presence of metric perturbations at the end of inflation. We obtain the amplitude of the corresponding magnetic fields on super-Hubble scales and compare it with the requirements of the galactic dynamo mechanism for different values of the spectral index. Finally we discuss the possible effects of the dissipation of such fields in the form of gravitational waves.
1809.00384
Ewelina Szarek
Ewelina Szarek
Soft anomalous dimension matrices in heavy quark-antiquark hadroproduction in association with a gluon jet
36 pages, 8 figures
null
10.5506/APhysPolB.49.1839
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the soft anomalous dimension (SAD) matrices for production of massive quarks $Q$ and $\bar{Q}$ in association with a gluon jet, from massless quarks $q$ and antiquarks $\bar{q}$: $q\bar{q}\rightarrow Q\bar{Q}g$, and in the gluon scattering $gg\rightarrow Q\bar{Q}g$. To analyze the behaviour of the eigenvalues of SAD matrices we perform numerical studies of their eigensystems at two special kinematical configurations.
[ { "created": "Sun, 2 Sep 2018 20:20:09 GMT", "version": "v1" } ]
2018-12-05
[ [ "Szarek", "Ewelina", "" ] ]
We compute the soft anomalous dimension (SAD) matrices for production of massive quarks $Q$ and $\bar{Q}$ in association with a gluon jet, from massless quarks $q$ and antiquarks $\bar{q}$: $q\bar{q}\rightarrow Q\bar{Q}g$, and in the gluon scattering $gg\rightarrow Q\bar{Q}g$. To analyze the behaviour of the eigenvalues of SAD matrices we perform numerical studies of their eigensystems at two special kinematical configurations.
hep-ph/0508017
Mofazzal Azam
Mofazzal Azam
Some comments on the divergence of perturbation series in Quantum Eletrodynamics
Final Version, To appear in Modern Physics Letters A
Mod.Phys.Lett.A21:1161-1166,2006
10.1142/S0217732306019463
null
hep-ph hep-th quant-ph
null
It has been argued by Dyson that the perturbation series in coupling constant in QED can not be convergent. We find that similiar albeit slightly different arguments lead to the divergence of the series of $1/N_f$ expansion in QED.
[ { "created": "Mon, 1 Aug 2005 09:29:21 GMT", "version": "v1" }, { "created": "Tue, 13 Sep 2005 09:22:35 GMT", "version": "v2" }, { "created": "Mon, 19 Dec 2005 07:43:35 GMT", "version": "v3" } ]
2010-11-05
[ [ "Azam", "Mofazzal", "" ] ]
It has been argued by Dyson that the perturbation series in coupling constant in QED can not be convergent. We find that similiar albeit slightly different arguments lead to the divergence of the series of $1/N_f$ expansion in QED.
hep-ph/9604354
null
S. Dawson (BNL) and H. Haber (UCSC)
Electroweak Symmetry Breaking and Physics Beyond the Standard Model
To be published in {\it Electroweak Symmetry Breaking and New Physics at the TeV Scale}, edited by T.L. Barklow, S. Dawson, H.E. Haber, and J.L. Siegrist. Latex using equ.sty and lprocldpf.sty. Equation numbering corrected
null
null
BNL-HEP/TH-96/5, SCIPP-96/14
hep-ph
null
In order to extend the Standard Model to TeV scale energies one must address two basic questions: (1) What is the complete description of the effective theory of fundamental particles at and below the electroweak scale? and (2) What is the dynamics responsible for electroweak symmetry breaking? The answers to these questions are crucial for addressing the third outstanding question of particle physics: What are the origins of the Standard Model parameters? We briefly summarize current theoretical approaches to answering these questions.
[ { "created": "Thu, 18 Apr 1996 18:14:52 GMT", "version": "v1" }, { "created": "Tue, 14 May 1996 14:01:31 GMT", "version": "v2" } ]
2008-02-03
[ [ "Dawson", "S.", "", "BNL" ], [ "Haber", "H.", "", "UCSC" ] ]
In order to extend the Standard Model to TeV scale energies one must address two basic questions: (1) What is the complete description of the effective theory of fundamental particles at and below the electroweak scale? and (2) What is the dynamics responsible for electroweak symmetry breaking? The answers to these questions are crucial for addressing the third outstanding question of particle physics: What are the origins of the Standard Model parameters? We briefly summarize current theoretical approaches to answering these questions.
hep-ph/0609237
Nora Brambilla
Nora Brambilla
Systems of two heavy quarks with effective field theories
7 pages, Invited talk at the 7th Workshop on Continuous Advances in QCD, Minneapolis, Minnesota, May 11-14, 2006
null
10.1142/9789812708267_0014
IFUM 870-FT
hep-ph
null
I discuss results and applications of QCD nonrelativistic effective field theories for systems with two heavy quarks.
[ { "created": "Fri, 22 Sep 2006 14:53:50 GMT", "version": "v1" } ]
2017-08-23
[ [ "Brambilla", "Nora", "" ] ]
I discuss results and applications of QCD nonrelativistic effective field theories for systems with two heavy quarks.