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1402.1186
G.R. Boroun
G.R.Boroun
Nonlinear correction to the longitudinal structure function at small x
4 pages, 1 figures. arXiv admin note: substantial text overlap with arXiv:1402.0864, arXiv:1402.0752
Eur. Phys. J. A 43, (2010)335
10.1140/epja/i2010-10919-9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We computed the longitudinal proton structure function $F_{L}$, using the nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-parisi (NLDGLAP) evolution equation approach at small $x$. For the gluon distribution, the nonlinear effects are related to the longitudinal structure function. As, the very small $x$ behavior of the gluon distribution is obtained by solving the Gribov, Levin, Ryskin, Mueller and Qiu (GLR-MQ) evolution equation with the nonlinear shadowing term incorporated. We show, the strong rise that is corresponding to the linear QCD evolution equations, can be tamed by screening effects. Consequently, the obtained longitudinal structure function shows a tamed growth at small $x$. We computed the predictions for all detail of the nonlinear longitudinal structure function in the kinematic range where it has been measured by $H1$ collaboration and compared with computation Moch, Vermaseren and Vogt at the second order with input data from MRST QCD fit.
[ { "created": "Tue, 4 Feb 2014 15:19:15 GMT", "version": "v1" } ]
2014-02-07
[ [ "Boroun", "G. R.", "" ] ]
We computed the longitudinal proton structure function $F_{L}$, using the nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-parisi (NLDGLAP) evolution equation approach at small $x$. For the gluon distribution, the nonlinear effects are related to the longitudinal structure function. As, the very small $x$ behavior of the gluon distribution is obtained by solving the Gribov, Levin, Ryskin, Mueller and Qiu (GLR-MQ) evolution equation with the nonlinear shadowing term incorporated. We show, the strong rise that is corresponding to the linear QCD evolution equations, can be tamed by screening effects. Consequently, the obtained longitudinal structure function shows a tamed growth at small $x$. We computed the predictions for all detail of the nonlinear longitudinal structure function in the kinematic range where it has been measured by $H1$ collaboration and compared with computation Moch, Vermaseren and Vogt at the second order with input data from MRST QCD fit.
hep-ph/0407193
Adam Bzdak
Adam Bzdak
Central inclusive dijets production by double pomeron exchange. Comparison with the CDF results
8 pages, 2 figures
Phys.Lett. B608 (2005) 64-68
10.1016/j.physletb.2005.01.004
null
hep-ph
null
Using the Landshoff-Nachtmann model of the pomeron, rapidity and transverse momentum distributions of gluon jets produced by double pomeron exchange in pp collisions are calculated. The comparison with the CDF Run I results on the central inclusive dijets production cross sections is performed. We find the model to give correct order of magnitude for the measured cross sections.
[ { "created": "Fri, 16 Jul 2004 17:38:01 GMT", "version": "v1" }, { "created": "Wed, 5 Jan 2005 16:28:19 GMT", "version": "v2" } ]
2009-11-10
[ [ "Bzdak", "Adam", "" ] ]
Using the Landshoff-Nachtmann model of the pomeron, rapidity and transverse momentum distributions of gluon jets produced by double pomeron exchange in pp collisions are calculated. The comparison with the CDF Run I results on the central inclusive dijets production cross sections is performed. We find the model to give correct order of magnitude for the measured cross sections.
2210.05106
Shi Pu
Shuo Lin, Ren-Jie Wang, JIan-Fei Wang, Hao-Jie Xu, Shi Pu, Qun Wang
Photoproduction of $e^{+}e^{-}$ in peripheral isobar collisions
17 pages, 6 figures
null
10.1103/PhysRevD.107.054004
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We investigate the photoproduction of di-electrons in peripheral collisions of $_{44}^{96}\textrm{Ru}+_{44}^{96}\textrm{Ru}$ and $_{40}^{96}\textrm{Zr}+_{40}^{96}\textrm{Zr}$ at 200 GeV. With the charge and mass density distributions given by the calculation of the density functional theory, we calculate the spectra of transverse momentum, invariant mass and azimuthal angle for di-electrons at 40-80\% centrality. The ratios of these spectra in Ru+Ru collisions over to Zr+Zr collisions are shown to be smaller than $(44/40)^{4}$ (the ratio of $Z^{4}$ for Ru and Zr) at low transverse momentum. The deviation arises from the different mass and charge density distributions in Ru and Zr. So the photoproduction of di-leptons in isobar collisions may provide a new way to probe the nuclear structure.
[ { "created": "Tue, 11 Oct 2022 02:50:01 GMT", "version": "v1" } ]
2023-03-15
[ [ "Lin", "Shuo", "" ], [ "Wang", "Ren-Jie", "" ], [ "Wang", "JIan-Fei", "" ], [ "Xu", "Hao-Jie", "" ], [ "Pu", "Shi", "" ], [ "Wang", "Qun", "" ] ]
We investigate the photoproduction of di-electrons in peripheral collisions of $_{44}^{96}\textrm{Ru}+_{44}^{96}\textrm{Ru}$ and $_{40}^{96}\textrm{Zr}+_{40}^{96}\textrm{Zr}$ at 200 GeV. With the charge and mass density distributions given by the calculation of the density functional theory, we calculate the spectra of transverse momentum, invariant mass and azimuthal angle for di-electrons at 40-80\% centrality. The ratios of these spectra in Ru+Ru collisions over to Zr+Zr collisions are shown to be smaller than $(44/40)^{4}$ (the ratio of $Z^{4}$ for Ru and Zr) at low transverse momentum. The deviation arises from the different mass and charge density distributions in Ru and Zr. So the photoproduction of di-leptons in isobar collisions may provide a new way to probe the nuclear structure.
hep-ph/9605361
Thomas G. Rizzo
Thomas G. Rizzo
Anomalous Chromoelectric and Chromomagnetic Moments of the Top Quark at the NLC
8 pages plus figures, compressed PS file
null
null
SLAC-PUB-7154
hep-ph
null
The production of top quark pairs in association with a hard gluon in $e^+e^-$ collisions at the NLC provides an opportunity to probe for anomalous $t\bar tg$ couplings, \eg, the chromoelectric and chromomagnetic moments of the top. We demonstrate that an examination of the energy spectrum of the additional gluon jet can yield strong constraints on the size of these two anomalous couplings. The results are shown to be quite sensitive to the cut on the minimum gluon jet energy needed to remove events where the final state $b$-quark radiates strongly. The possibility of using additional observables to improve the sensitivity to anomalous couplings is briefly discussed. [To appear in {\it Physics and Technology of the Next Linear Collider}, eds. D.\ Burke and M.\ Peskin, reports submitted to Snowmass 1996.]
[ { "created": "Mon, 20 May 1996 23:30:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rizzo", "Thomas G.", "" ] ]
The production of top quark pairs in association with a hard gluon in $e^+e^-$ collisions at the NLC provides an opportunity to probe for anomalous $t\bar tg$ couplings, \eg, the chromoelectric and chromomagnetic moments of the top. We demonstrate that an examination of the energy spectrum of the additional gluon jet can yield strong constraints on the size of these two anomalous couplings. The results are shown to be quite sensitive to the cut on the minimum gluon jet energy needed to remove events where the final state $b$-quark radiates strongly. The possibility of using additional observables to improve the sensitivity to anomalous couplings is briefly discussed. [To appear in {\it Physics and Technology of the Next Linear Collider}, eds. D.\ Burke and M.\ Peskin, reports submitted to Snowmass 1996.]
hep-ph/0509156
Kacper Zalewski
Kacper Zalewski
Pitfalls of the theory of Bose-Einstein correlations in multiple particle production
8 pages LateX, no figures, report at the QCD'05 Conference Montpellier July 2005
null
null
null
hep-ph
null
Some basic difficulties and ambiguities on the way from the measured momentum distributions to the inferred properties of the interaction regions are reviewed and discussed.
[ { "created": "Thu, 15 Sep 2005 11:14:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zalewski", "Kacper", "" ] ]
Some basic difficulties and ambiguities on the way from the measured momentum distributions to the inferred properties of the interaction regions are reviewed and discussed.
hep-ph/0002173
Rahul Sinha
D. London, N. Sinha, R. Sinha
Is it possible to Measure the Weak Phase of a Penguin Diagram?
4 pages, latex, no figures, talk given by R. Sinha at the 3rd International Conference on B Physics and CP Violation, Taipei, Taiwan, December 3-7, 1999, to appear in the Proceedings
null
10.1142/9789812791870_0017
IMSc/00/02/05, UdeM-GPP-TH-00-66
hep-ph
null
The $b\to d$ penguin amplitude receives contributions from internal $u$, $c$ and $t$-quarks. We show that it is impossible to measure the weak phase of any of these penguin contributions without theoretical input. However, a single assumption involving the hadronic parameters makes it possible to obtain the weak phase and test for the presence of new physics in the $b\to d$ flavour-changing neutral current.
[ { "created": "Wed, 16 Feb 2000 11:46:37 GMT", "version": "v1" } ]
2016-11-23
[ [ "London", "D.", "" ], [ "Sinha", "N.", "" ], [ "Sinha", "R.", "" ] ]
The $b\to d$ penguin amplitude receives contributions from internal $u$, $c$ and $t$-quarks. We show that it is impossible to measure the weak phase of any of these penguin contributions without theoretical input. However, a single assumption involving the hadronic parameters makes it possible to obtain the weak phase and test for the presence of new physics in the $b\to d$ flavour-changing neutral current.
0802.1328
Yeo-Yie Charng
Yeo-Yie Charng, Da-Shin Lee, Chung Ngoc Leung, and Kin-Wang Ng
Affleck-Dine Baryogenesis, Split Supersymmetry, and Inflation
version accepted for publication in PRD
Phys.Rev.D80:063519,2009
10.1103/PhysRevD.80.063519
null
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that, in the context of split supersymmetry, a simple model with a single complex scalar field can produce chaotic inflation and generate the observed amount of baryon asymmetry via the Affleck-Dine mechanism. While the inflaton quantum fluctuations give rise to curvature perturbation, we show that quantum fluctuations of the phase of the scalar field can produce baryonic isocurvature perturbation. Combining with constraints from WMAP data, all parameters in the model can be determined to within a narrow range.
[ { "created": "Sun, 10 Feb 2008 15:47:04 GMT", "version": "v1" }, { "created": "Tue, 27 Jan 2009 21:21:43 GMT", "version": "v2" }, { "created": "Tue, 14 Jul 2009 13:30:41 GMT", "version": "v3" } ]
2009-11-06
[ [ "Charng", "Yeo-Yie", "" ], [ "Lee", "Da-Shin", "" ], [ "Leung", "Chung Ngoc", "" ], [ "Ng", "Kin-Wang", "" ] ]
It is shown that, in the context of split supersymmetry, a simple model with a single complex scalar field can produce chaotic inflation and generate the observed amount of baryon asymmetry via the Affleck-Dine mechanism. While the inflaton quantum fluctuations give rise to curvature perturbation, we show that quantum fluctuations of the phase of the scalar field can produce baryonic isocurvature perturbation. Combining with constraints from WMAP data, all parameters in the model can be determined to within a narrow range.
1008.0923
Dremin
I.M. Dremin
Polarization properties of the quark-gluon medium
6 p., talk at HSQCD2010, Gatchina
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Collective properties of the quark-gluon medium induced by its polarization are described by macroscopic QCD equations. The parton currents traversing it lead to emission of Cherenkov gluons, the wake effect and the transition radiation. Comparison with experimental data of RHIC reveals large value of the chromopermittivity of the medium while cosmic ray data at higher energies (close to LHC) favor much smaller values. The dispersion equations show that the proper modes of the medium are unstable.
[ { "created": "Thu, 5 Aug 2010 08:00:42 GMT", "version": "v1" } ]
2010-08-06
[ [ "Dremin", "I. M.", "" ] ]
Collective properties of the quark-gluon medium induced by its polarization are described by macroscopic QCD equations. The parton currents traversing it lead to emission of Cherenkov gluons, the wake effect and the transition radiation. Comparison with experimental data of RHIC reveals large value of the chromopermittivity of the medium while cosmic ray data at higher energies (close to LHC) favor much smaller values. The dispersion equations show that the proper modes of the medium are unstable.
1405.4664
Shinya Fukasawa
Shinya Fukasawa
Search for Non-Standard Interactions by atmospheric neutrino
4 pages, 3 figures, Proceedings of Rencontres de Moriond, EW session, 2014
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the effects of neutral current Non-Standard Interactions in propagation on atmospheric neutrino experiments such as Super-Kamiokande and Hyper-Kamiokande. With the ansatz where the parameters which have strong constraints from other experiments are neglected, we show how these experiments put constraints on the remaining parameters of the Non-Standard Interactions.
[ { "created": "Mon, 19 May 2014 10:31:25 GMT", "version": "v1" } ]
2014-05-20
[ [ "Fukasawa", "Shinya", "" ] ]
We investigate the effects of neutral current Non-Standard Interactions in propagation on atmospheric neutrino experiments such as Super-Kamiokande and Hyper-Kamiokande. With the ansatz where the parameters which have strong constraints from other experiments are neglected, we show how these experiments put constraints on the remaining parameters of the Non-Standard Interactions.
hep-ph/9606332
Erwin Mirkes
Erwin Mirkes and Dieter Zeppenfeld
QCD Corrections to Jet Cross Sections in DIS
Invited talk given at the Zeuthen Workshop on Elementary Particle Theory, "QCD and QED in Higher Orders", Rheinsberg, Germany, 21-26 April 1996; presented by E. Mirkes. 6 pages, 4 figures. The complete paper, including figures, is also available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Nucl.Phys.Proc.Suppl. 51C (1996) 273-280
10.1016/S0920-5632(96)90036-5
TTP96-24, MADPH-96-946
hep-ph
null
Next-to-leading order corrections to jet cross sections in deep inelastic scattering at HERA are studied. The predicted jet rates allow for a precise determination of $\alpha_s(\mu_R)$ at HERA over a wide range of $\mu_R$. We argue, that the ``natural'' renormalization and factorization scale is set by the average $k_T^B$ of the jets in the Breit frame and suggest to divide the data in corresponding $<k_T^B>$ intervals. Some implications for the determination of the gluon density and the associated forward jet production in the low $x$ regime at HERA are briefly discussed.
[ { "created": "Fri, 14 Jun 1996 08:40:55 GMT", "version": "v1" } ]
2015-06-25
[ [ "Mirkes", "Erwin", "" ], [ "Zeppenfeld", "Dieter", "" ] ]
Next-to-leading order corrections to jet cross sections in deep inelastic scattering at HERA are studied. The predicted jet rates allow for a precise determination of $\alpha_s(\mu_R)$ at HERA over a wide range of $\mu_R$. We argue, that the ``natural'' renormalization and factorization scale is set by the average $k_T^B$ of the jets in the Breit frame and suggest to divide the data in corresponding $<k_T^B>$ intervals. Some implications for the determination of the gluon density and the associated forward jet production in the low $x$ regime at HERA are briefly discussed.
2211.04390
Michael Fucilla
Michael Fucilla, Andrey V. Grabovsky, Lech Szymanowski, Emilie Li and Samuel Wallon
Diffractive di-hadron production at NLO within the shockwave formalism
6 pages, 2 figures. Presented by E. Li at Diffraction and Low-x 2022, Corigliano Calabro, Italy, September 24-30, 2022
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the next-leading-order cross-sections for diffractive electro- or photoproduction of a pair of hadrons with large $p_T$, out of a nucleus or a nucleon. A hybrid factorization is used, mixing collinear and small-$x$ factorizations, more precisely shockwave formalism. We demonstrate the cancellation of divergences and extract the finite parts of the differential cross-section in general kinematics.
[ { "created": "Tue, 8 Nov 2022 17:29:56 GMT", "version": "v1" } ]
2022-11-09
[ [ "Fucilla", "Michael", "" ], [ "Grabovsky", "Andrey V.", "" ], [ "Szymanowski", "Lech", "" ], [ "Li", "Emilie", "" ], [ "Wallon", "Samuel", "" ] ]
We compute the next-leading-order cross-sections for diffractive electro- or photoproduction of a pair of hadrons with large $p_T$, out of a nucleus or a nucleon. A hybrid factorization is used, mixing collinear and small-$x$ factorizations, more precisely shockwave formalism. We demonstrate the cancellation of divergences and extract the finite parts of the differential cross-section in general kinematics.
1311.6150
Michal Silarski
M. Silarski
Phenomenological studies of the low energy dynamics in the $ppK^+K^-$ system
Proceedings of the EFB22 conference (4 pages, 1 figure)
Few-Body Syst (2014) 55:57-60
10.1007/s00601-013-0744-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we review studies of the near threshold $pp \to ppK^+K^-$ reaction done with the COSY-11 and ANKE detectors. We discuss phenomenological studies of the $ppK^+K^-$ dynamics, in particular the recent investigations on the $K^+K^-$ final state interaction are presented.
[ { "created": "Sun, 24 Nov 2013 18:16:32 GMT", "version": "v1" } ]
2014-01-14
[ [ "Silarski", "M.", "" ] ]
In this article we review studies of the near threshold $pp \to ppK^+K^-$ reaction done with the COSY-11 and ANKE detectors. We discuss phenomenological studies of the $ppK^+K^-$ dynamics, in particular the recent investigations on the $K^+K^-$ final state interaction are presented.
1612.04612
Ilya F. Ginzburg
I. F. Ginzburg, M. Krawczyk
A simple criterium for CP conservation in the most general 2HDM
10 pages, 2 figures
Phys. Rev. D 96, 055030 (2017)
10.1103/PhysRevD.96.055030
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We find set of necessary and sufficient conditions for CP conservation in the most general 2HDM in terms of observable quantities. This set contains two relatively easily testable simple conditions instead of usually discussed three more complex ones.
[ { "created": "Wed, 14 Dec 2016 12:47:49 GMT", "version": "v1" } ]
2017-10-11
[ [ "Ginzburg", "I. F.", "" ], [ "Krawczyk", "M.", "" ] ]
We find set of necessary and sufficient conditions for CP conservation in the most general 2HDM in terms of observable quantities. This set contains two relatively easily testable simple conditions instead of usually discussed three more complex ones.
2106.09939
Ye Xing
Ye Xing, Yuekun Niu
The study of doubly charmed pentaquark $c c \bar qqq$ with the SU(3) symmetry
18 pages, 4 figures
null
10.1140/epjc/s10052-021-09730-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the masses and lifetimes of doubly charmed pentaquark $P_{cc\bar qqq}(q=u,d,s)$ primarily. The operation of masses carried out by the doubly heavy triquark-diquark model, whose results suggests the existence of stable states $cc\bar s ud$ with the parity $J^P=\frac{1}{2}^-$. The roughly calculation about lifetimes show the short magnitudes, $(4.65^{+0.71}_{-0.55})\times 10^{-13}s $ for the parity $J^P=\frac{1}{2}^-$ and $(0.93^{+0.14}_{-0.11})\times 10^{-12} s $ for $J^P=\frac{3}{2}^-$. Since the pentaquark $cc\bar s ud$ is interpreted as the stable bound states against strong decays, then we will focus on the production and possible decay channels of the pentaquark in the next step, the study would be fairly valuable supports for future experiments. For completeness, we systematically studied the production from $\Omega_{ccc}$ and the decay modes in the framework SU(3) flavor symmetry, including the processes of semi-leptonic and two body non-leptonic decays. Synthetically, we make a collection of the golden channels.
[ { "created": "Fri, 18 Jun 2021 06:41:05 GMT", "version": "v1" } ]
2021-11-24
[ [ "Xing", "Ye", "" ], [ "Niu", "Yuekun", "" ] ]
We study the masses and lifetimes of doubly charmed pentaquark $P_{cc\bar qqq}(q=u,d,s)$ primarily. The operation of masses carried out by the doubly heavy triquark-diquark model, whose results suggests the existence of stable states $cc\bar s ud$ with the parity $J^P=\frac{1}{2}^-$. The roughly calculation about lifetimes show the short magnitudes, $(4.65^{+0.71}_{-0.55})\times 10^{-13}s $ for the parity $J^P=\frac{1}{2}^-$ and $(0.93^{+0.14}_{-0.11})\times 10^{-12} s $ for $J^P=\frac{3}{2}^-$. Since the pentaquark $cc\bar s ud$ is interpreted as the stable bound states against strong decays, then we will focus on the production and possible decay channels of the pentaquark in the next step, the study would be fairly valuable supports for future experiments. For completeness, we systematically studied the production from $\Omega_{ccc}$ and the decay modes in the framework SU(3) flavor symmetry, including the processes of semi-leptonic and two body non-leptonic decays. Synthetically, we make a collection of the golden channels.
hep-ph/9712417
Matthias Neubert
I. Caprini (Bucharest), L. Lellouch and M. Neubert (CERN)
Dispersive Bounds on the Shape of B -> D^(*) l nu Form Factors
32 pages, 6 figures
Nucl.Phys. B530 (1998) 153-181
10.1016/S0550-3213(98)00350-2
CERN-TH/97-91, CPT-97/P3480
hep-ph
null
Dispersive constraints on the shape of the form factors which describe the exclusive decays B -> D^(*) l nu are derived by fully exploiting spin symmetry in the ground-state doublet of heavy-light mesons. The analysis includes all twenty B^(*) -> D^(*) semileptonic form factors. Heavy-quark symmetry, with both short-distance and 1/m_Q corrections included, is used to provide relations between the form factors near zero recoil. Simple one-parameter functions are derived, which describe the form factors in the semileptonic region with an accuracy of better than 2%. The implications of our results for the determination of |V_cb| are discussed.
[ { "created": "Wed, 17 Dec 1997 13:23:22 GMT", "version": "v1" } ]
2009-10-30
[ [ "Caprini", "I.", "", "Bucharest" ], [ "Lellouch", "L.", "", "CERN" ], [ "Neubert", "M.", "", "CERN" ] ]
Dispersive constraints on the shape of the form factors which describe the exclusive decays B -> D^(*) l nu are derived by fully exploiting spin symmetry in the ground-state doublet of heavy-light mesons. The analysis includes all twenty B^(*) -> D^(*) semileptonic form factors. Heavy-quark symmetry, with both short-distance and 1/m_Q corrections included, is used to provide relations between the form factors near zero recoil. Simple one-parameter functions are derived, which describe the form factors in the semileptonic region with an accuracy of better than 2%. The implications of our results for the determination of |V_cb| are discussed.
1801.03276
C. Q. Geng
C.Q. Geng, Y.K. Hsiao, Chia-Wei Liu and Tien-Hsueh Tsai
Anti-triplet charmed baryon decays with SU(3) Flavor Symmetry
12 pages, no figure, revised version accepted by PRD
Phys. Rev. D 97, 073006 (2018)
10.1103/PhysRevD.97.073006
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the decays of the anti-triplet charmed baryon state $(\Xi_c^0,\Xi_c^+,\Lambda_c^+)$ based on the $SU(3)$ flavor symmetry. In particular, after predicting ${\cal B}(\Xi_c^0\to \Xi^-\pi^+)=(15.7 \pm 0.7)\times 10^{-3}$ and ${\cal B}(\Xi_c^+\to\Xi^-\pi^+\pi^+)=(14.7\pm 8.4)\times 10^{-3}$, we extract that ${\cal B}(\Xi_c^0\to\Lambda K^-\pi^+,\Lambda K^+K^-,\Xi^- e^+\nu_e)=(16.8\pm 2.3,0.45\pm 0.11,48.7\pm 17.4)\times 10^{-3}$ and ${\cal B}(\Xi_c^+\to p K_s^0 K_s^0,\Sigma^+ K^-\pi^+,\Xi^0\pi^+\pi^0,\Xi^0 e^+\nu_e)=(1.3\pm 0.8,13.8\pm 8.0,33.8\pm 21.9,33.8^{+21.9}_{-22.6})\times 10^{-3}$. We also find that ${\cal B}(\Xi_c^0\to \Xi^{0} \eta,\Xi^{0} \eta')=(1.7 ^{+ 1.0 }_{- 1.7 },8.6 ^{+ 11.0 }_{-\;\,6.3 })\times 10^{-3}$, ${\cal B}(\Xi_c^0\to \Lambda^{0} \eta,\Lambda^{0} \eta')=(1.6 ^{+ 1.2 }_{- 0.8 },9.4 ^{+ 11.6 }_{-\;\,6.8 })\times 10^{-4}$ and ${\cal B}(\Xi_c^+\to \Sigma^{+} \eta,\Sigma^{+} \eta')=(28.4 ^{+ 8.2 }_{- 6.9 },13.2 ^{+ 24.0 }_{- 11.9 })\times 10^{-4}$. These $\Xi_c$ decays with the branching ratios of $O(10^{-4}-10^{-3})$ are clearly promising to be observed by the BESIII and LHCb experiments.
[ { "created": "Wed, 10 Jan 2018 09:20:13 GMT", "version": "v1" }, { "created": "Sat, 7 Apr 2018 19:43:14 GMT", "version": "v2" } ]
2018-05-02
[ [ "Geng", "C. Q.", "" ], [ "Hsiao", "Y. K.", "" ], [ "Liu", "Chia-Wei", "" ], [ "Tsai", "Tien-Hsueh", "" ] ]
We study the decays of the anti-triplet charmed baryon state $(\Xi_c^0,\Xi_c^+,\Lambda_c^+)$ based on the $SU(3)$ flavor symmetry. In particular, after predicting ${\cal B}(\Xi_c^0\to \Xi^-\pi^+)=(15.7 \pm 0.7)\times 10^{-3}$ and ${\cal B}(\Xi_c^+\to\Xi^-\pi^+\pi^+)=(14.7\pm 8.4)\times 10^{-3}$, we extract that ${\cal B}(\Xi_c^0\to\Lambda K^-\pi^+,\Lambda K^+K^-,\Xi^- e^+\nu_e)=(16.8\pm 2.3,0.45\pm 0.11,48.7\pm 17.4)\times 10^{-3}$ and ${\cal B}(\Xi_c^+\to p K_s^0 K_s^0,\Sigma^+ K^-\pi^+,\Xi^0\pi^+\pi^0,\Xi^0 e^+\nu_e)=(1.3\pm 0.8,13.8\pm 8.0,33.8\pm 21.9,33.8^{+21.9}_{-22.6})\times 10^{-3}$. We also find that ${\cal B}(\Xi_c^0\to \Xi^{0} \eta,\Xi^{0} \eta')=(1.7 ^{+ 1.0 }_{- 1.7 },8.6 ^{+ 11.0 }_{-\;\,6.3 })\times 10^{-3}$, ${\cal B}(\Xi_c^0\to \Lambda^{0} \eta,\Lambda^{0} \eta')=(1.6 ^{+ 1.2 }_{- 0.8 },9.4 ^{+ 11.6 }_{-\;\,6.8 })\times 10^{-4}$ and ${\cal B}(\Xi_c^+\to \Sigma^{+} \eta,\Sigma^{+} \eta')=(28.4 ^{+ 8.2 }_{- 6.9 },13.2 ^{+ 24.0 }_{- 11.9 })\times 10^{-4}$. These $\Xi_c$ decays with the branching ratios of $O(10^{-4}-10^{-3})$ are clearly promising to be observed by the BESIII and LHCb experiments.
1711.10029
R. Sekhar Chivukula
R. Sekhar Chivukula
The Top Quark: Past, Present, and Future
Talk presented at the XXVIII International Symposium on Lepton Photon Interactions at High Energies, Sun Yat-Sen University, Guangzhou, China from Aug 7 to Aug 12, 2017. (Fixed references.)
null
null
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk I discuss the widespread impact of the top quark on phenomena in elementary particle physics as codified through the Standard Model (SM), its important role in motivating the possiblity of physics beyond the Standard Model (BSM), and its use as a signal for detailed studies of the SM and searches for BSM physics.
[ { "created": "Mon, 27 Nov 2017 22:45:03 GMT", "version": "v1" }, { "created": "Wed, 29 Nov 2017 14:00:45 GMT", "version": "v2" } ]
2017-11-30
[ [ "Chivukula", "R. Sekhar", "" ] ]
In this talk I discuss the widespread impact of the top quark on phenomena in elementary particle physics as codified through the Standard Model (SM), its important role in motivating the possiblity of physics beyond the Standard Model (BSM), and its use as a signal for detailed studies of the SM and searches for BSM physics.
hep-ph/9703352
null
B.V.Geshkenbein
Restrictions on the Hadronic Contribution to the Muon $(g-2)$-factor and to the Pion Electromagnetic Formfactor from Analytical Properties of the Pion Electromagnetic Formfactor
in LaTeX, pages 12
null
null
ITEP Preprint 11-97
hep-ph
null
We investigate restrictions on the hadronic contribution to the muon $(g-2)$ factor and to the pion electromagnetic formfactor from the analytical properties of the pion formfactor and the experimental data of the pion formfactor in the space-like [1] region. The values of the pion formfactor of [1] have been improved (see Table 1) and the values of the pion formfactor have been calculated at 20 additional points (see Table 2).
[ { "created": "Tue, 18 Mar 1997 11:38:56 GMT", "version": "v1" } ]
2007-05-23
[ [ "Geshkenbein", "B. V.", "" ] ]
We investigate restrictions on the hadronic contribution to the muon $(g-2)$ factor and to the pion electromagnetic formfactor from the analytical properties of the pion formfactor and the experimental data of the pion formfactor in the space-like [1] region. The values of the pion formfactor of [1] have been improved (see Table 1) and the values of the pion formfactor have been calculated at 20 additional points (see Table 2).
1811.12058
Joydeep Roy
Joydeep Roy
Probing leptoquark chirality via top polarization at the Colliders
10 pages, 4 figures, Added references
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anomalies in recent LHCb, Belle and Babar measurements of $R_{D^{(*)}}$, and $R_{K^{(*)}}$ in $B$ decays may indicate the new physics beyond the Standard Model (SM). The leptoquarks ($LQ$) that couple to the $3^{\mathrm{rd}}$ generation quarks and leptons have been proposed as a viable new physics (NP) explanation. Such left-handed $LQ$s can couple to both bottom and top quarks. Since top particles decay before the hadronization, it is possible to reconstruct chirality of boosted top quarks and consequently the chirality of top coupling to the $LQ$s. We perform analysis on the top quark's chirality in the pair-production channel of the $LQ$, which can be purely left-handed in comparison to unpolarized $t\bar{t}$ SM background. We study the prospects of distinguishing the chirality of a potential $LQ$ signal for the high luminosity run of the LHC and other future colliders.
[ { "created": "Thu, 29 Nov 2018 10:55:02 GMT", "version": "v1" }, { "created": "Sat, 12 Jan 2019 21:56:57 GMT", "version": "v2" } ]
2019-01-15
[ [ "Roy", "Joydeep", "" ] ]
Anomalies in recent LHCb, Belle and Babar measurements of $R_{D^{(*)}}$, and $R_{K^{(*)}}$ in $B$ decays may indicate the new physics beyond the Standard Model (SM). The leptoquarks ($LQ$) that couple to the $3^{\mathrm{rd}}$ generation quarks and leptons have been proposed as a viable new physics (NP) explanation. Such left-handed $LQ$s can couple to both bottom and top quarks. Since top particles decay before the hadronization, it is possible to reconstruct chirality of boosted top quarks and consequently the chirality of top coupling to the $LQ$s. We perform analysis on the top quark's chirality in the pair-production channel of the $LQ$, which can be purely left-handed in comparison to unpolarized $t\bar{t}$ SM background. We study the prospects of distinguishing the chirality of a potential $LQ$ signal for the high luminosity run of the LHC and other future colliders.
1312.4401
Gui-Jun Ding
Cai-Chang Li, Gui-Jun Ding
Generalised CP and Trimaximal TM$_1$ Lepton Mixing in $S_4$ Family Symmetry
28 pages
null
10.1016/j.nuclphysb.2014.02.002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct two flavor models based on $S_4$ family symmetry and generalised CP symmetry. In both models, the $S_4$ family symmetry is broken down to the $Z^{SU}_2$ subgroup in the neutrino sector, as a consequence, the trimaximal $\text{TM}_1$ lepton mixing is produced. Depending on the free parameters in the flavon potential, the Dirac CP is predicted to be either conserved or maximally broken, and the Majorana CP phases are trivial. The two models differ in the neutrino sector. The flavon fields are involved in the Dirac mass terms at leading order in the first model, and the neutrino mass matrix contains three real parameters such that the absolute neutrino masses are fixed. Nevertheless, the flavon fields enter into the Majorana mass terms at leading order in the second model. The leading order lepton mixing is of the tri-bimaximal form which is broken down to $\text{TM}_1$ by the next to leading order contributions.
[ { "created": "Mon, 16 Dec 2013 15:34:19 GMT", "version": "v1" }, { "created": "Tue, 18 Feb 2014 10:52:39 GMT", "version": "v2" } ]
2014-02-19
[ [ "Li", "Cai-Chang", "" ], [ "Ding", "Gui-Jun", "" ] ]
We construct two flavor models based on $S_4$ family symmetry and generalised CP symmetry. In both models, the $S_4$ family symmetry is broken down to the $Z^{SU}_2$ subgroup in the neutrino sector, as a consequence, the trimaximal $\text{TM}_1$ lepton mixing is produced. Depending on the free parameters in the flavon potential, the Dirac CP is predicted to be either conserved or maximally broken, and the Majorana CP phases are trivial. The two models differ in the neutrino sector. The flavon fields are involved in the Dirac mass terms at leading order in the first model, and the neutrino mass matrix contains three real parameters such that the absolute neutrino masses are fixed. Nevertheless, the flavon fields enter into the Majorana mass terms at leading order in the second model. The leading order lepton mixing is of the tri-bimaximal form which is broken down to $\text{TM}_1$ by the next to leading order contributions.
1603.04859
Francesco D'Eramo
Francesco D'Eramo, Kevin Hambleton, Stefano Profumo, Tim Stefaniak
Dark Matter Inelastic Up-Scattering with the Interstellar Plasma: An Exciting New Source of X-Ray Lines, including at 3.5 keV
16 pages, 9 figures; v2, version published in Physical Review D
Phys. Rev. D 93, 103011 (2016)
10.1103/PhysRevD.93.103011
SCIPP 16/04
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the phenomenology of a class of models where the dark matter particle can inelastically up-scatter to a heavier excited state via off-diagonal dipolar interactions with the interstellar plasma (gas or free electrons). The heavier particle then rapidly decays back to the dark matter particle plus a quasi-monochromatic photon. For the process to occur at appreciable rates, the mass splitting between the heavier state and the dark matter must be comparable to, or smaller than, the kinetic energy of particles in the plasma. As a result, the predicted photon line falls in the soft X-ray range, or, potentially, at arbitrarily lower energies. We explore experimental constraints from cosmology and particle physics, and present accurate calculations of the dark matter thermal relic density and of the flux of monochromatic X-rays from thermal plasma excitation. We find that the model provides a natural explanation for the observed 3.5 keV line from clusters of galaxies and from the Galactic center, and is consistent with null detections of the line from dwarf galaxies. The unique line shape, which will be resolved by future observations with the Hitomi (formerly Astro-H) satellite, and the predicted unique morphology and target-temperature dependence will enable easy discrimination of this class of models versus other scenarios for the generation of the 3.5 keV line or of any other unidentified line across the electromagnetic spectrum.
[ { "created": "Tue, 15 Mar 2016 20:00:05 GMT", "version": "v1" }, { "created": "Tue, 7 Jun 2016 01:55:01 GMT", "version": "v2" } ]
2016-06-08
[ [ "D'Eramo", "Francesco", "" ], [ "Hambleton", "Kevin", "" ], [ "Profumo", "Stefano", "" ], [ "Stefaniak", "Tim", "" ] ]
We explore the phenomenology of a class of models where the dark matter particle can inelastically up-scatter to a heavier excited state via off-diagonal dipolar interactions with the interstellar plasma (gas or free electrons). The heavier particle then rapidly decays back to the dark matter particle plus a quasi-monochromatic photon. For the process to occur at appreciable rates, the mass splitting between the heavier state and the dark matter must be comparable to, or smaller than, the kinetic energy of particles in the plasma. As a result, the predicted photon line falls in the soft X-ray range, or, potentially, at arbitrarily lower energies. We explore experimental constraints from cosmology and particle physics, and present accurate calculations of the dark matter thermal relic density and of the flux of monochromatic X-rays from thermal plasma excitation. We find that the model provides a natural explanation for the observed 3.5 keV line from clusters of galaxies and from the Galactic center, and is consistent with null detections of the line from dwarf galaxies. The unique line shape, which will be resolved by future observations with the Hitomi (formerly Astro-H) satellite, and the predicted unique morphology and target-temperature dependence will enable easy discrimination of this class of models versus other scenarios for the generation of the 3.5 keV line or of any other unidentified line across the electromagnetic spectrum.
hep-ph/0502193
John Ellis
John Ellis, Yitzhak Frishman
Exotic Baryons in Two-Dimensional QCD
15 pages latex, no figures
JHEP 0508:081,2005
10.1088/1126-6708/2005/08/081
CERN-PH-TH/2005-017
hep-ph hep-th
null
Two-dimensional QCD has often been used as a laboratory for studying the full four-dimensional theory, providing, for example, an explicit realization of baryons as solitons. We review aspects of conventional baryons in two-dimensional QCD, including the classical and quantum contributions to their masses. We then discuss the spectrum of exotic baryons in two-dimensional QCD, commenting on the solitonic radius inferred from the excitation spectrum as well as the two-dimensional version of the Goldberger-Treiman relation relating meson couplings to current matrix elements. Two-dimensional QCD provides strong overall support to the chiral-soliton picture for the structure of normal and exotic baryons in four dimensions.
[ { "created": "Mon, 21 Feb 2005 16:21:45 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ellis", "John", "" ], [ "Frishman", "Yitzhak", "" ] ]
Two-dimensional QCD has often been used as a laboratory for studying the full four-dimensional theory, providing, for example, an explicit realization of baryons as solitons. We review aspects of conventional baryons in two-dimensional QCD, including the classical and quantum contributions to their masses. We then discuss the spectrum of exotic baryons in two-dimensional QCD, commenting on the solitonic radius inferred from the excitation spectrum as well as the two-dimensional version of the Goldberger-Treiman relation relating meson couplings to current matrix elements. Two-dimensional QCD provides strong overall support to the chiral-soliton picture for the structure of normal and exotic baryons in four dimensions.
hep-ph/0406053
Vladimir A. Smirnov
G. Heinrich, V.A. Smirnov
Analytical Evaluation of Dimensionally Regularized Massive On-Shell Double Boxes
14 pages LaTeX, references updated, to appear in Phys. Lett. B
Phys.Lett. B598 (2004) 55-66
10.1016/j.physletb.2004.07.058
DESY 04-094
hep-ph
null
The method of Mellin-Barnes representation is used to calculate dimensionally regularized massive on-shell double box Feynman diagrams contributing to Bhabha scattering at two loops.
[ { "created": "Fri, 4 Jun 2004 10:57:23 GMT", "version": "v1" }, { "created": "Mon, 16 Aug 2004 13:05:58 GMT", "version": "v2" } ]
2009-11-10
[ [ "Heinrich", "G.", "" ], [ "Smirnov", "V. A.", "" ] ]
The method of Mellin-Barnes representation is used to calculate dimensionally regularized massive on-shell double box Feynman diagrams contributing to Bhabha scattering at two loops.
hep-ph/0510312
Zhi-Zhong Xing
Zhi-zhong Xing
A Novel Parametrization of tau-lepton Dominance and Simplified One-loop Renormalization-group Equations of Neutrino Mixing Angles and CP-violating Phases
RevTex 10 pages
Phys.Lett.B633:550-556,2006
10.1016/j.physletb.2005.12.023
null
hep-ph
null
We point out that the $\tau$-lepton dominance in the one-loop renormalization-group (RG) equations of neutrino mixing quantities allows us to set a criterion to choose the most suitable parametrization of the lepton flavor mixing matrix $U$: its elements $U^{}_{3i}$ (for $i=1,2,3$) should be as simple as possible. Such a novel parametrization is quite different from the "standard" one used in the literature and can lead to greatly simplified RG equations for three mixing angles and the physical CP-violating phase(s) in the standard model or its minimal supersymmetric extension, no matter whether neutrinos are Dirac or Majorana particles. Some important features of our analytical results and their phenomenological consequences are also discussed.
[ { "created": "Mon, 24 Oct 2005 08:15:50 GMT", "version": "v1" } ]
2011-04-12
[ [ "Xing", "Zhi-zhong", "" ] ]
We point out that the $\tau$-lepton dominance in the one-loop renormalization-group (RG) equations of neutrino mixing quantities allows us to set a criterion to choose the most suitable parametrization of the lepton flavor mixing matrix $U$: its elements $U^{}_{3i}$ (for $i=1,2,3$) should be as simple as possible. Such a novel parametrization is quite different from the "standard" one used in the literature and can lead to greatly simplified RG equations for three mixing angles and the physical CP-violating phase(s) in the standard model or its minimal supersymmetric extension, no matter whether neutrinos are Dirac or Majorana particles. Some important features of our analytical results and their phenomenological consequences are also discussed.
2007.10994
Ze Long Liu
Hai Tao Li, Ze Long Liu, Ivan Vitev
Heavy meson tomography of cold nuclear matter at the electron-ion collider
11 pages, 6 figures, 1 table, v2: journal version. Figure panels, references, and discussion added
null
10.1016/j.physletb.2021.136261
LA-UR-20-28936
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An important part of the physics program at the future electron-ion collider is to understand the nature of hadronization and the transport of energy and matter in large nuclei. Open heavy flavor production in deep inelastic scattering provides a new tool to address these critical questions. We present the first calculation of D-mesons and B-meson cross sections in electron-nucleus collisions at the EIC by including both next-to-leading order QCD corrections and cold nuclear matter effects. Our formalism employs generalized DGLAP evolution to include the contribution of in-medium parton showers, and is based on methods developed in soft-collinear effective theory with Glauber gluons that describe inclusive hadron production in reactions with nucleons and nuclei. The comprehensive study summarized here allows us to identify the optimal observables, center-of-mass energies, and kinematic regions most sensitive to the physics of energy loss and hadronization at the EIC.
[ { "created": "Tue, 21 Jul 2020 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 6 Apr 2021 17:54:58 GMT", "version": "v2" } ]
2021-04-07
[ [ "Li", "Hai Tao", "" ], [ "Liu", "Ze Long", "" ], [ "Vitev", "Ivan", "" ] ]
An important part of the physics program at the future electron-ion collider is to understand the nature of hadronization and the transport of energy and matter in large nuclei. Open heavy flavor production in deep inelastic scattering provides a new tool to address these critical questions. We present the first calculation of D-mesons and B-meson cross sections in electron-nucleus collisions at the EIC by including both next-to-leading order QCD corrections and cold nuclear matter effects. Our formalism employs generalized DGLAP evolution to include the contribution of in-medium parton showers, and is based on methods developed in soft-collinear effective theory with Glauber gluons that describe inclusive hadron production in reactions with nucleons and nuclei. The comprehensive study summarized here allows us to identify the optimal observables, center-of-mass energies, and kinematic regions most sensitive to the physics of energy loss and hadronization at the EIC.
0809.4773
Kochelev Nikolai Innokentevich
N.I.Kochelev
Instantons and Spin-Flavor effects in Hadron Physics
6 pages, 4 figures, based on the talk given at the XV Annual Seminar "Nonlinear Phenomena in Complex Systems", Belarus, May 20-23, 2008
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the role of instantons in the spectroscopy of ordinary and exotic hadrons as well as in high energy reactions. We argue that the instanton induced flavor- and spin-dependent quark-quark and quark-gluon interactions can explain many features of the hadron spectrum. The observed anomalous spin and flavor effects in various reactions with hadrons can also be understood within the instanton model for QCD vacuum.
[ { "created": "Sat, 27 Sep 2008 14:09:40 GMT", "version": "v1" }, { "created": "Tue, 30 Sep 2008 06:50:54 GMT", "version": "v2" }, { "created": "Mon, 6 Oct 2008 14:26:03 GMT", "version": "v3" } ]
2008-10-06
[ [ "Kochelev", "N. I.", "" ] ]
We discuss the role of instantons in the spectroscopy of ordinary and exotic hadrons as well as in high energy reactions. We argue that the instanton induced flavor- and spin-dependent quark-quark and quark-gluon interactions can explain many features of the hadron spectrum. The observed anomalous spin and flavor effects in various reactions with hadrons can also be understood within the instanton model for QCD vacuum.
hep-ph/9810393
Shang-Yung Wang
D. Boyanovsky, H. J. de Vega, Y.J. Ng, D.-S. Lee, S.-Y. Wang
Fermion Damping in a Fermion-Scalar Plasma
REVTEX, 16 pages, 3 eps figures included, published version. To be published in Phys. Rev. D
Phys. Rev. D 59, 105001 (1999)
10.1103/PhysRevD.59.105001
null
hep-ph
null
In this article we study the dynamics of fermions in a fermion-scalar plasma. We begin by obtaining the effective in-medium Dirac equation in real time which is fully renormalized and causal and leads to the initial value problem. For a heavy scalar we find the novel result that the decay of the scalar into fermion pairs in the medium leads to damping of the fermionic excitations and their in-medium propagation as quasiparticles. That is, the fermions acquire a width due to the decay of the heavier scalar in the medium. We find the damping rate to lowest order in the Yukawa coupling for arbitrary values of scalar and fermion masses, temperature and fermion momentum. An all-order expression for the damping rate in terms of the exact quasiparticle wave functions is established. A kinetic Boltzmann approach to the relaxation of the fermionic distribution function confirms the damping of fermionic excitations as a consequence of the induced decay of heavy scalars in the medium. A linearization of the Boltzmann equation near equilibrium clearly displays the relationship between the damping rate of fermionic mean fields and the fermion interaction rate to lowest order in the Yukawa coupling directly in real time.
[ { "created": "Fri, 16 Oct 1998 22:55:24 GMT", "version": "v1" }, { "created": "Wed, 13 Jan 1999 17:39:23 GMT", "version": "v2" } ]
2016-08-25
[ [ "Boyanovsky", "D.", "" ], [ "de Vega", "H. J.", "" ], [ "Ng", "Y. J.", "" ], [ "Lee", "D. -S.", "" ], [ "Wang", "S. -Y.", "" ] ]
In this article we study the dynamics of fermions in a fermion-scalar plasma. We begin by obtaining the effective in-medium Dirac equation in real time which is fully renormalized and causal and leads to the initial value problem. For a heavy scalar we find the novel result that the decay of the scalar into fermion pairs in the medium leads to damping of the fermionic excitations and their in-medium propagation as quasiparticles. That is, the fermions acquire a width due to the decay of the heavier scalar in the medium. We find the damping rate to lowest order in the Yukawa coupling for arbitrary values of scalar and fermion masses, temperature and fermion momentum. An all-order expression for the damping rate in terms of the exact quasiparticle wave functions is established. A kinetic Boltzmann approach to the relaxation of the fermionic distribution function confirms the damping of fermionic excitations as a consequence of the induced decay of heavy scalars in the medium. A linearization of the Boltzmann equation near equilibrium clearly displays the relationship between the damping rate of fermionic mean fields and the fermion interaction rate to lowest order in the Yukawa coupling directly in real time.
1809.06286
Debojit Sarkar
Debojit Sarkar
Investigating jet-medium interaction using charge dependent three-particle correlation in high multiplicity p+Pb collisions at $\sqrt{s_{NN} }$ = 5.02 TeV
null
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although many observations in high multiplicity p+Pb collisions at the LHC indicate striking similarity to heavy ion collisions, no evidence of jet-medium interactions has been observed till date. We study the effect of jet-medium interaction on the charge dependent three-particle correlation in high multiplicity p+Pb collisions at $\sqrt{s_{NN} }$ = 5.02 TeV using EPOS 3 event generator. The short range component of the three-particle correlation is dominated by the jet fragmentation and has a unique charge dependence as observed in the minimum bias p+Au collisions at the RHIC energy. In EPOS 3, similar pattern has been observed in the lower multiplicity classes of p+Pb collisions where jet fragmentation plays the dominant role. Interestingly, the charge dependence of three-particle correlation gets diminished in the higher multiplicity classes of p+Pb collisions where the jet-medium interactions as implemented in EPOS 3 plays an important role. The current study can, therefore, provide possible ways to investigate the jet-medium interaction in high multiplicity classes of small collision systems at the LHC energies.
[ { "created": "Mon, 17 Sep 2018 15:47:58 GMT", "version": "v1" } ]
2018-09-18
[ [ "Sarkar", "Debojit", "" ] ]
Although many observations in high multiplicity p+Pb collisions at the LHC indicate striking similarity to heavy ion collisions, no evidence of jet-medium interactions has been observed till date. We study the effect of jet-medium interaction on the charge dependent three-particle correlation in high multiplicity p+Pb collisions at $\sqrt{s_{NN} }$ = 5.02 TeV using EPOS 3 event generator. The short range component of the three-particle correlation is dominated by the jet fragmentation and has a unique charge dependence as observed in the minimum bias p+Au collisions at the RHIC energy. In EPOS 3, similar pattern has been observed in the lower multiplicity classes of p+Pb collisions where jet fragmentation plays the dominant role. Interestingly, the charge dependence of three-particle correlation gets diminished in the higher multiplicity classes of p+Pb collisions where the jet-medium interactions as implemented in EPOS 3 plays an important role. The current study can, therefore, provide possible ways to investigate the jet-medium interaction in high multiplicity classes of small collision systems at the LHC energies.
1606.03026
Stephen P. Martin
Stephen P. Martin
Signal-background interference for a singlet spin-0 digluon resonance at the LHC
14 pages. v5 fixes errors in equations (2.10)-(2.15)
Phys. Rev. D 94, 035003 (2016)
10.1103/PhysRevD.94.035003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dijet mass distributions can be used to search for spin-0 resonances that couple to two gluons. I show that there is a substantial impact on such searches from the interference between the resonant signal and the continuum QCD background amplitudes. The signal dijet mass distribution is qualitatively modified by this interference, compared to the naive expectation from considering only the pure resonant contribution, even if the total width of the resonance is minimal and very small compared to the experimental dijet mass resolution. The impact becomes more drastic as the total width of the resonance increases. These considerations are illustrated using examples relevant to the 750 GeV diphoton excess recently observed at the LHC.
[ { "created": "Thu, 9 Jun 2016 16:56:17 GMT", "version": "v1" }, { "created": "Fri, 10 Jun 2016 19:41:38 GMT", "version": "v2" }, { "created": "Mon, 20 Jun 2016 16:04:40 GMT", "version": "v3" }, { "created": "Tue, 19 Jul 2016 19:37:06 GMT", "version": "v4" }, { "created": "Tue, 23 Jul 2019 02:30:59 GMT", "version": "v5" } ]
2019-07-24
[ [ "Martin", "Stephen P.", "" ] ]
Dijet mass distributions can be used to search for spin-0 resonances that couple to two gluons. I show that there is a substantial impact on such searches from the interference between the resonant signal and the continuum QCD background amplitudes. The signal dijet mass distribution is qualitatively modified by this interference, compared to the naive expectation from considering only the pure resonant contribution, even if the total width of the resonance is minimal and very small compared to the experimental dijet mass resolution. The impact becomes more drastic as the total width of the resonance increases. These considerations are illustrated using examples relevant to the 750 GeV diphoton excess recently observed at the LHC.
hep-ph/9512269
Fischer Jan
Jan Fischer
High-order behaviour and summation methods in perturbative QCD
15 pages, one PS figure, Latex2e
Acta Phys.Polon.B27:2549-2566,1996
null
CERN-TH/95-325
hep-ph
null
After reviewing basic facts about large-order behaviour of perturbation expansions in various fields of physics, I consider several alternatives to the Borel summation method and discuss their relevance to different physical situations. Then I convey news about the singularities in the Borel plane, and discuss the topical subject of the resummation of renormalon chains and its application in various QCD processes.
[ { "created": "Mon, 11 Dec 1995 09:07:41 GMT", "version": "v1" } ]
2014-11-17
[ [ "Fischer", "Jan", "" ] ]
After reviewing basic facts about large-order behaviour of perturbation expansions in various fields of physics, I consider several alternatives to the Borel summation method and discuss their relevance to different physical situations. Then I convey news about the singularities in the Borel plane, and discuss the topical subject of the resummation of renormalon chains and its application in various QCD processes.
hep-ph/0607115
Emi Kou
J. Alwall, R. Frederix, J.-M. Gerard, A. Giammanco, M. Herquet, S. Kalinin, E. Kou, V. Lemaitre, F. Maltoni
Is Vtb=1 ?
19 pages, 8 figures
Eur.Phys.J.C49:791-801,2007
10.1140/epjc/s10052-006-0137-y
CP3-06-01
hep-ph hep-ex
null
The strongest constraint on Vtb presently comes from the 3 x 3 unitarity of the CKM matrix, which fixes Vtb to be very close to one. If the unitarity is relaxed, current information from top production at Tevatron still leaves open the possibility that Vtb is sizably smaller than one. In minimal extensions of the standard model with extra heavy quarks, the unitarity constraints are much weaker and the EW precision parameters entail the strongest bounds on Vtb. We discuss the experimental perspectives of discovering and identifying such new physics models at the Tevatron and the LHC, through a precise measurement of Vtb from the single top cross sections and by the study of processes where the extra heavy quarks are produced.
[ { "created": "Tue, 11 Jul 2006 19:51:44 GMT", "version": "v1" }, { "created": "Tue, 11 Jul 2006 21:27:22 GMT", "version": "v2" } ]
2014-11-18
[ [ "Alwall", "J.", "" ], [ "Frederix", "R.", "" ], [ "Gerard", "J. -M.", "" ], [ "Giammanco", "A.", "" ], [ "Herquet", "M.", "" ], [ "Kalinin", "S.", "" ], [ "Kou", "E.", "" ], [ "Lemaitre", "V.", "" ], [ "Maltoni", "F.", "" ] ]
The strongest constraint on Vtb presently comes from the 3 x 3 unitarity of the CKM matrix, which fixes Vtb to be very close to one. If the unitarity is relaxed, current information from top production at Tevatron still leaves open the possibility that Vtb is sizably smaller than one. In minimal extensions of the standard model with extra heavy quarks, the unitarity constraints are much weaker and the EW precision parameters entail the strongest bounds on Vtb. We discuss the experimental perspectives of discovering and identifying such new physics models at the Tevatron and the LHC, through a precise measurement of Vtb from the single top cross sections and by the study of processes where the extra heavy quarks are produced.
1405.0919
Jian-Rong Zhang
Jian-Rong Zhang
Possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states
talk given at the workshop on Hadron Nuclear Physics held from July 18 to 22, 2013 at Zhangjiajie, China
Int. J. Mod. Phys. Conf. Ser. 29, 1460220 (2014)
10.1142/S2010194514602208
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, we give a brief review of our work studying the possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states from QCD sum rules.
[ { "created": "Fri, 2 May 2014 07:22:45 GMT", "version": "v1" } ]
2015-06-19
[ [ "Zhang", "Jian-Rong", "" ] ]
In this talk, we give a brief review of our work studying the possibility of $\Sigma_{c}(2800)$ and $\Lambda_{c}(2940)^{+}$ as $S$-wave $D^{(*)}N$ molecular states from QCD sum rules.
2111.12589
Ulrich Haisch
Ulrich Haisch and Gabri\"el Koole
Off-shell Higgs production at the LHC as a probe of the trilinear Higgs coupling
29 pages, 9 figures, 3 tables; extended version including a new appendix as accepted for publication in JHEP
null
10.1007/JHEP02(2022)030
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of the Standard Model effective field theory (SMEFT) we examine the constraints on the trilinear Higgs coupling that originate from off-shell Higgs production in proton-proton collisions. Our calculation of the $gg \to h^\ast \to Z Z \to 4 \ell$ process includes two-loop corrections to gluon-gluon-fusion Higgs production and one-loop corrections to the Higgs propagator and its decay. Employing a matrix-element based kinematic discriminant we determine the reach of LHC Run 3 and the high-luminosity option of the LHC in constraining the relevant SMEFT Wilson coefficients. We present constraints that are not only competitive with but also complementary to the projected indirect limits that one expects to obtain from inclusive measurements of single-Higgs production processes at future LHC runs.
[ { "created": "Wed, 24 Nov 2021 16:07:46 GMT", "version": "v1" }, { "created": "Tue, 1 Feb 2022 12:00:17 GMT", "version": "v2" } ]
2022-02-23
[ [ "Haisch", "Ulrich", "" ], [ "Koole", "Gabriël", "" ] ]
In the context of the Standard Model effective field theory (SMEFT) we examine the constraints on the trilinear Higgs coupling that originate from off-shell Higgs production in proton-proton collisions. Our calculation of the $gg \to h^\ast \to Z Z \to 4 \ell$ process includes two-loop corrections to gluon-gluon-fusion Higgs production and one-loop corrections to the Higgs propagator and its decay. Employing a matrix-element based kinematic discriminant we determine the reach of LHC Run 3 and the high-luminosity option of the LHC in constraining the relevant SMEFT Wilson coefficients. We present constraints that are not only competitive with but also complementary to the projected indirect limits that one expects to obtain from inclusive measurements of single-Higgs production processes at future LHC runs.
0811.0875
Stanley J. Brodsky
Stanley J. Brodsky
Dynamic versus Static Structure Functions and Novel Diffractive Effects in QCD
8 pages, 1 figure. Presented at Diffraction 2008: International Workshop On Diffraction In High Energy Physics 9-14 Sep 2008, La Londe-les-Maures, France
AIP Conf.Proc.1105:315-322,2009
10.1063/1.3122202
SLAC-PUB-13454
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Initial- and final-state rescattering, neglected in the parton model, have a profound effect in QCD hard-scattering reactions, predicting single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high centrality heavy ion collisions. I emphasize the importance of distinguishing between static observables such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical observables which include the effects of rescattering.
[ { "created": "Thu, 6 Nov 2008 06:12:28 GMT", "version": "v1" } ]
2009-09-11
[ [ "Brodsky", "Stanley J.", "" ] ]
Initial- and final-state rescattering, neglected in the parton model, have a profound effect in QCD hard-scattering reactions, predicting single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high centrality heavy ion collisions. I emphasize the importance of distinguishing between static observables such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical observables which include the effects of rescattering.
hep-ph/9812248
Xiao-Gang He
Xiao-Gang He (NTU) and Guey-Lin Lin (NCTU)
$B \to \eta' X_s$ in the Standard Model
Corrected a few minor typos. 6 page with 1 figure. Sprocl.Sty. Talk presented at the Workshop on CP Violation, Adelaide, Australia, 3-6 July, 1998
null
null
null
hep-ph
null
We study $B \to \eta' X_s$ within the framework of the Standard Model. Several mechanisms such as $b \to \eta' s g$ from the QCD anomaly, and $b \to \eta's $ and $B\to \eta' s \bar q$ from four-quark operators are treated simultaneously. We find that the first mechanism give a significant contribution to the branching ratio for $B\to \eta' X_s$, while the other two mechanisms account for about 15% of the experimental value. The Standard Model prediction for $B\to \eta' X_s$ is consistent with the CLEO data.
[ { "created": "Fri, 4 Dec 1998 08:45:45 GMT", "version": "v1" }, { "created": "Mon, 14 Dec 1998 08:18:50 GMT", "version": "v2" } ]
2007-05-23
[ [ "He", "Xiao-Gang", "", "NTU" ], [ "Lin", "Guey-Lin", "", "NCTU" ] ]
We study $B \to \eta' X_s$ within the framework of the Standard Model. Several mechanisms such as $b \to \eta' s g$ from the QCD anomaly, and $b \to \eta's $ and $B\to \eta' s \bar q$ from four-quark operators are treated simultaneously. We find that the first mechanism give a significant contribution to the branching ratio for $B\to \eta' X_s$, while the other two mechanisms account for about 15% of the experimental value. The Standard Model prediction for $B\to \eta' X_s$ is consistent with the CLEO data.
hep-ph/0304011
Julien Serreau
Julien Serreau
Disoriented Chiral Condensate Formation in Heavy Ion Collisions?
12 pages, 5 figures. Talk at TH-2002, 'International Conference on Theoretical Physics', UNESCO, Paris, France
null
null
HD-THEP-03-08
hep-ph hep-ex nucl-ex nucl-th
null
One of the main aims of present and upcoming high energy heavy ion collision experiments is to study new phases of matter at extreme temperature and density. It is expected that a nontrivial classical pion field configuration can occasionally form during the out-of-equilibrium chiral phase transition. We have recently shown that, contrarily to what has been assumed so far, this configuration is not identical to the so-called disoriented chiral condensate (DCC), proposed in the early 1990's. A detailed analysis reveals that a more realistic picture is that of an ``unpolarized'' DCC, where the Fourier modes of the field have completely independent orientations in isospin space instead of being aligned with each other as in the original DCC. This has important implications concerning the possible detection of the phenomenon. In particular, the main expected signature of the original DCC, which is used in most experimental searches, is absent in the unpolarized case. We point out that the fact that no evidence of DCC formation has been reported so far in nuclear collisions actually agrees with our present theoretical understanding. New experimental strategies should be designed to look for the unpolarized DCC in existing data from SPS as well as in future searches at RHIC and LHC.
[ { "created": "Tue, 1 Apr 2003 15:20:34 GMT", "version": "v1" } ]
2007-05-23
[ [ "Serreau", "Julien", "" ] ]
One of the main aims of present and upcoming high energy heavy ion collision experiments is to study new phases of matter at extreme temperature and density. It is expected that a nontrivial classical pion field configuration can occasionally form during the out-of-equilibrium chiral phase transition. We have recently shown that, contrarily to what has been assumed so far, this configuration is not identical to the so-called disoriented chiral condensate (DCC), proposed in the early 1990's. A detailed analysis reveals that a more realistic picture is that of an ``unpolarized'' DCC, where the Fourier modes of the field have completely independent orientations in isospin space instead of being aligned with each other as in the original DCC. This has important implications concerning the possible detection of the phenomenon. In particular, the main expected signature of the original DCC, which is used in most experimental searches, is absent in the unpolarized case. We point out that the fact that no evidence of DCC formation has been reported so far in nuclear collisions actually agrees with our present theoretical understanding. New experimental strategies should be designed to look for the unpolarized DCC in existing data from SPS as well as in future searches at RHIC and LHC.
1401.1277
Thomas Mehen
Thomas Mehen (Duke U.)
Exotic Quarkonium Spectroscopy: X(3872), Z_b(10610), and Z_b(10650) in Non-Relativistic Effective Theory
5 pages, to appear in the proceedings of PhiPsi2013: International Workshop on e+e- collisions from Phi to Psi 2013, Rome, Italy, Sep. 9-12, 2013
null
10.1142/S2010194514604311
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This talk summarizes recent developments in quarkonium spectroscopy. I comment on the relation between the Z_b(10610) and Z_b(10650) and recently observed Z_c(3900) and Z_c(4025) states. Then I discuss a number of calculations using non-relativistic effective field theory for the X(3872), Z_b(10610), and Z_b(10650), under the assumption that these are shallow molecular bound states of charm or bottom mesons.
[ { "created": "Tue, 7 Jan 2014 05:41:38 GMT", "version": "v1" } ]
2015-06-18
[ [ "Mehen", "Thomas", "", "Duke U." ] ]
This talk summarizes recent developments in quarkonium spectroscopy. I comment on the relation between the Z_b(10610) and Z_b(10650) and recently observed Z_c(3900) and Z_c(4025) states. Then I discuss a number of calculations using non-relativistic effective field theory for the X(3872), Z_b(10610), and Z_b(10650), under the assumption that these are shallow molecular bound states of charm or bottom mesons.
hep-ph/0402074
Durmus Demir
Durmus A. Demir
Higgs Quark Couplings in SUSY with CP and Flavor Violations
To appear in the Proceedings of SUSY 2003, held at the University of Arizona, Tucson, AZ, 5-10 June 2003
null
null
FTPI-MINN-04/06, UMN-TH-2233/04
hep-ph
null
In minimal supersymmetric model with a light Higgs sector, explicit CP violation and most general flavor mixings in the sfermion sector, integration of the superpartners out of the spectrum induces potentially large contributions to the Yukawa couplings of light quarks via those of the heavier ones. These corrections can be sizeable even for moderate values of tan(beta), and remain nonvanishing even if all superpartners decouple. Then Higgs boson couplings to light quarks assume spectacular enhancements; in particular, couplings to down and strange quarks become degenerate with that to the bottom quark. There arise strikingly non-standard effects that can show up in both Higgs boson searches and FCNC observables.
[ { "created": "Fri, 6 Feb 2004 16:55:41 GMT", "version": "v1" }, { "created": "Sun, 8 Feb 2004 12:43:14 GMT", "version": "v2" } ]
2007-05-23
[ [ "Demir", "Durmus A.", "" ] ]
In minimal supersymmetric model with a light Higgs sector, explicit CP violation and most general flavor mixings in the sfermion sector, integration of the superpartners out of the spectrum induces potentially large contributions to the Yukawa couplings of light quarks via those of the heavier ones. These corrections can be sizeable even for moderate values of tan(beta), and remain nonvanishing even if all superpartners decouple. Then Higgs boson couplings to light quarks assume spectacular enhancements; in particular, couplings to down and strange quarks become degenerate with that to the bottom quark. There arise strikingly non-standard effects that can show up in both Higgs boson searches and FCNC observables.
1612.04701
Stefan Gieseke
Stefan Gieseke, Frash\"er Loshaj, Patrick Kirchgae{\ss}er
Soft and diffractive scattering with the cluster model in Herwig
13 pages, many figures
null
10.1140/epjc/s10052-017-4727-7
KA-TP-42-2016, MCNET-16-46
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new model for soft interactions in the event-generator Herwig. The model consists of two components. One to model diffractive final states on the basis of the cluster hadronization model and a second component that addresses soft multiple interactions as multiple particle production in multi- peripheral kinematics. We present much improved results for minimum-bias measurements at various LHC energies.
[ { "created": "Wed, 14 Dec 2016 16:04:54 GMT", "version": "v1" } ]
2017-04-05
[ [ "Gieseke", "Stefan", "" ], [ "Loshaj", "Frashër", "" ], [ "Kirchgaeßer", "Patrick", "" ] ]
We present a new model for soft interactions in the event-generator Herwig. The model consists of two components. One to model diffractive final states on the basis of the cluster hadronization model and a second component that addresses soft multiple interactions as multiple particle production in multi- peripheral kinematics. We present much improved results for minimum-bias measurements at various LHC energies.
hep-ph/9807424
Tao Han
Tao Han and Ren-Jie Zhang
Extending the Higgs Boson Reach at the Upgraded Fermilab Tevatron
revised version, to appear in PRL
Phys.Rev.Lett. 82 (1999) 25-28
10.1103/PhysRevLett.82.25
MADPH-98-1067
hep-ph hep-ex
null
We study the observability for a Standard Model-like Higgs boson at an upgraded Tevatron via the modes $p \bar p \to gg \to h \to \ww \to \ljj$ and $\ll$. We find that with c. m. energy of 2 TeV and an integrated luminosity of 30 fb$^{-1}$ the signal may be observable for the mass range of $135 {\gev} \lsim \mh \lsim 180$ GeV at a $3-5\sigma$ statistical level. We conclude that the upgraded Tevatron may have the potential to detect a SM-like Higgs boson in the mass range from the LEP2 reach to 180 GeV.
[ { "created": "Mon, 20 Jul 1998 17:00:16 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 1998 21:58:24 GMT", "version": "v2" } ]
2009-10-31
[ [ "Han", "Tao", "" ], [ "Zhang", "Ren-Jie", "" ] ]
We study the observability for a Standard Model-like Higgs boson at an upgraded Tevatron via the modes $p \bar p \to gg \to h \to \ww \to \ljj$ and $\ll$. We find that with c. m. energy of 2 TeV and an integrated luminosity of 30 fb$^{-1}$ the signal may be observable for the mass range of $135 {\gev} \lsim \mh \lsim 180$ GeV at a $3-5\sigma$ statistical level. We conclude that the upgraded Tevatron may have the potential to detect a SM-like Higgs boson in the mass range from the LEP2 reach to 180 GeV.
1008.2813
Richard J. van Kooten
R. Van Kooten (for the D0 Collaboration)
D0 Evidence for CP Violation and Implication for CPT Violation in B-Meson Mixing
5 pages, 1 figure; presented at the Fifth Meeting on CPT and Lorentz Symmetry, Indiana University, Bloomington, Indiana, June 28-July 2, 2010. CPT violation treatment not from D0 Collaboration, but work initiated at meeting
null
10.1142/9789814327688_0031
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An analysis from the D0 Collaboration measuring the charge asymmetry A^b_sl of like-sign dimuon events due to semileptonic b-hadron decays at the Fermilab Tevatron Collider is described. It differs by 3.2 standard deviations from the Standard Model prediction to provide first evidence of CPT-invariant anomalous CP violation in the mixing of neutral B mesons, and is compared to the CP-violating phase obtained from a D0 analysis of the time-dependent decay angles in B0_s -> J/psi phi. If CPT violation is allowed, the dimuon asymmetry also yields the first sensitivity to CPT violation in the B0_s system.
[ { "created": "Tue, 17 Aug 2010 04:03:55 GMT", "version": "v1" } ]
2019-08-21
[ [ "Van Kooten", "R.", "", "for the D0 Collaboration" ] ]
An analysis from the D0 Collaboration measuring the charge asymmetry A^b_sl of like-sign dimuon events due to semileptonic b-hadron decays at the Fermilab Tevatron Collider is described. It differs by 3.2 standard deviations from the Standard Model prediction to provide first evidence of CPT-invariant anomalous CP violation in the mixing of neutral B mesons, and is compared to the CP-violating phase obtained from a D0 analysis of the time-dependent decay angles in B0_s -> J/psi phi. If CPT violation is allowed, the dimuon asymmetry also yields the first sensitivity to CPT violation in the B0_s system.
2403.13007
Claude A. Pruneau
Claude Pruneau, Sumit Basu, Victor Gonzalez, Brian Hanley, Ana Marin, Alexandru F. Dobrin, Alexandru Manea
Mixed Species Charge and Baryon Balance Functions Studies with PYTHIA
5 figures, 12 pages
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Mixed species charge and baryon balance functions are computed based on proton--proton (pp) collisions simulated with the PYTHIA8 model. Simulations are performed with selected values of the collision energy $\sqrt{s}$ and the Monash tune and the Ropes and Shoving modes of PYTHIA8 to explore whether such measurements provide useful new information and constraints on mechanisms of particle production in pp collisions. Charge balance functions are studied based on mixed pairs of pions, kaons, and protons, whereas baryon balance functions are computed for mixed low mass strange and non-strange baryons. Both charge and baryon balance functions of mixed particle pairs feature shapes and amplitudes that sensitively depend on the particle considered owing largely to the particle production mechanisms implemented in PYTHIA. The evolution of balance functions integrals with the longitudinal width of the acceptance are presented and one finds that sums of such integrals for a given reference particle obey expected sum rules for both charge and baryon balance functions. Additionally, both types of balance functions are found to evolve in shape and amplitude with increasing collision energy $\sqrt{s}$ and the PYTHIA tunes considered.
[ { "created": "Sat, 16 Mar 2024 14:56:01 GMT", "version": "v1" }, { "created": "Fri, 22 Mar 2024 22:16:04 GMT", "version": "v2" } ]
2024-03-26
[ [ "Pruneau", "Claude", "" ], [ "Basu", "Sumit", "" ], [ "Gonzalez", "Victor", "" ], [ "Hanley", "Brian", "" ], [ "Marin", "Ana", "" ], [ "Dobrin", "Alexandru F.", "" ], [ "Manea", "Alexandru", "" ] ]
Mixed species charge and baryon balance functions are computed based on proton--proton (pp) collisions simulated with the PYTHIA8 model. Simulations are performed with selected values of the collision energy $\sqrt{s}$ and the Monash tune and the Ropes and Shoving modes of PYTHIA8 to explore whether such measurements provide useful new information and constraints on mechanisms of particle production in pp collisions. Charge balance functions are studied based on mixed pairs of pions, kaons, and protons, whereas baryon balance functions are computed for mixed low mass strange and non-strange baryons. Both charge and baryon balance functions of mixed particle pairs feature shapes and amplitudes that sensitively depend on the particle considered owing largely to the particle production mechanisms implemented in PYTHIA. The evolution of balance functions integrals with the longitudinal width of the acceptance are presented and one finds that sums of such integrals for a given reference particle obey expected sum rules for both charge and baryon balance functions. Additionally, both types of balance functions are found to evolve in shape and amplitude with increasing collision energy $\sqrt{s}$ and the PYTHIA tunes considered.
1111.4237
Andrzej Czarnecki
Andrzej Czarnecki, Xavier Garcia i Tormo, and William J. Marciano
Muon decay in orbit spectra for muon-electron conversion experiments
submitted to Proceedings of the International Conference on Exotic Atoms and Related Topics (EXA 2011)
null
10.1007/s10751-011-0540-0
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have determined in detail the electron spectrum in the decay of bound muons. These results are especially relevant for the upcoming muon-electron conversion experiments.
[ { "created": "Thu, 17 Nov 2011 23:16:51 GMT", "version": "v1" } ]
2015-06-03
[ [ "Czarnecki", "Andrzej", "" ], [ "Tormo", "Xavier Garcia i", "" ], [ "Marciano", "William J.", "" ] ]
We have determined in detail the electron spectrum in the decay of bound muons. These results are especially relevant for the upcoming muon-electron conversion experiments.
hep-ph/0303246
Chao-Qiang Geng
C.Q. Geng and C.C. Liu
Study of $B_{s}\to (\eta,\eta',\phi)\ell\bar{\ell}$ Decays
21 pages, 6 Figures, to be published in J. Phys. G
J.Phys.G29:1103-1118,2003
10.1088/0954-3899/29/6/313
null
hep-ph
null
We study the rare decays of $B_{s} \to M_s\ell \bar{\ell}$ ($M_s=\eta, \eta',\phi$ and $\ell=\nu,e,\mu,\tau$) in the standard model. With the hadronic form factors evaluated in the light front and constituent quark models, we estimate the decay branching ratios, respectively. We also discuss the longitudinal lepton polarization and forward-backward asymmetries.
[ { "created": "Fri, 28 Mar 2003 20:08:03 GMT", "version": "v1" } ]
2008-11-26
[ [ "Geng", "C. Q.", "" ], [ "Liu", "C. C.", "" ] ]
We study the rare decays of $B_{s} \to M_s\ell \bar{\ell}$ ($M_s=\eta, \eta',\phi$ and $\ell=\nu,e,\mu,\tau$) in the standard model. With the hadronic form factors evaluated in the light front and constituent quark models, we estimate the decay branching ratios, respectively. We also discuss the longitudinal lepton polarization and forward-backward asymmetries.
2112.14116
Rudolf Faustov
V.P. Gerdt, A. Karimkhodzhaev, R.N. Faustov
Hadronic Vacuum Polarization and Test of Quantum Electrodynamics at Low Energies
12 pages, unpublished JINR preprint 1978
null
null
JINR P2-11308, 1978
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parameterization of the pion electromagnetic form factor and new experimental data on the $e^+e^-$ hadrons annihilation cross section. Then, the contribution from the hadronic vacuum polarization to the muon anomalous magnetic moment and the Lamb shift in muonic atoms are calculated.
[ { "created": "Tue, 28 Dec 2021 12:30:52 GMT", "version": "v1" } ]
2021-12-30
[ [ "Gerdt", "V. P.", "" ], [ "Karimkhodzhaev", "A.", "" ], [ "Faustov", "R. N.", "" ] ]
A hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parameterization of the pion electromagnetic form factor and new experimental data on the $e^+e^-$ hadrons annihilation cross section. Then, the contribution from the hadronic vacuum polarization to the muon anomalous magnetic moment and the Lamb shift in muonic atoms are calculated.
2109.02670
Sudhakantha Girmohanta
S. Girmohanta and R. Shrock
An Extra-Dimensional Model of Dark Matter
14 pages, 5 figures
Physical Review D 104, 115021 (2021)
10.1103/PhysRevD.104.115021
Stony Brook preprint YITP-SB-2021-15
hep-ph gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We present a model for dark matter with extra spatial dimensions in which Standard-Model (SM) fermions have localized wave functions. The underlying gauge group is $G_{\rm SM} \otimes {\rm U}(1)_z$, and the dark matter particle is a SM-singlet Dirac fermion, $\chi$, which is charged under the ${\rm U}(1)_z$ gauge symmetry. We show that the conventional wisdom that the mass of a Dirac fermion is naturally at the ultraviolet cutoff scale does not hold in this model. We further demonstrate that this model yields a dark matter relic abundance in agreement with observation and discuss constraints from direct and indirect searches for dark matter. The dark matter particle interacts weakly with matter and has negligibly small self-interactions. Very good fits to data from cosmological observations and experimental dark matter searches are obtained with $m_\chi$ in the multi-TeV range. A discussion is given of observational signatures and experimental tests of the model.
[ { "created": "Mon, 6 Sep 2021 18:00:05 GMT", "version": "v1" } ]
2021-12-21
[ [ "Girmohanta", "S.", "" ], [ "Shrock", "R.", "" ] ]
We present a model for dark matter with extra spatial dimensions in which Standard-Model (SM) fermions have localized wave functions. The underlying gauge group is $G_{\rm SM} \otimes {\rm U}(1)_z$, and the dark matter particle is a SM-singlet Dirac fermion, $\chi$, which is charged under the ${\rm U}(1)_z$ gauge symmetry. We show that the conventional wisdom that the mass of a Dirac fermion is naturally at the ultraviolet cutoff scale does not hold in this model. We further demonstrate that this model yields a dark matter relic abundance in agreement with observation and discuss constraints from direct and indirect searches for dark matter. The dark matter particle interacts weakly with matter and has negligibly small self-interactions. Very good fits to data from cosmological observations and experimental dark matter searches are obtained with $m_\chi$ in the multi-TeV range. A discussion is given of observational signatures and experimental tests of the model.
0705.4280
Dmitri Kharzeev
D. Kharzeev and K. Tuchin
Bulk viscosity of QCD matter near the critical temperature
8 pages, 1 figure
JHEP0809:093,2008
10.1088/1126-6708/2008/09/093
BNL/NT-07/23, RBRC-681
hep-ph hep-lat nucl-ex nucl-th
null
Kubo's formula relates bulk viscosity to the retarded Green's function of the trace of the energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the formula which relates the bulk viscosity to the energy density and pressure of hot matter. We then employ the available lattice QCD data to extract the bulk viscosity as a function of temperature. We find that close to the deconfinement temperature bulk viscosity becomes large, with viscosity-to-entropy ratio zeta/s about 1.
[ { "created": "Tue, 29 May 2007 19:34:29 GMT", "version": "v1" }, { "created": "Tue, 29 May 2007 20:38:51 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kharzeev", "D.", "" ], [ "Tuchin", "K.", "" ] ]
Kubo's formula relates bulk viscosity to the retarded Green's function of the trace of the energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the formula which relates the bulk viscosity to the energy density and pressure of hot matter. We then employ the available lattice QCD data to extract the bulk viscosity as a function of temperature. We find that close to the deconfinement temperature bulk viscosity becomes large, with viscosity-to-entropy ratio zeta/s about 1.
hep-ph/0305182
Jinfeng Liao
Lianyi He, Guang Bian, Jinfeng Liao and Pengfei Zhuang
Quark Probability Distribution at Finite Temperature and Density
7 papes, 4 figures
null
null
null
hep-ph
null
Quark deconfinement phase transition at finite temperature and density is investigated in the frame of quantum mechanics. By solving the Schr\"odinger equation for a heavy quark in a thermal mean field, we calculate the quark probability distribution as a function of temperature and density. The confined wave function in the vacuum expands outward rapidly when the temperature and density are high enough. The obtained phase transition line agrees qualitatively with the result of lattice QCD.
[ { "created": "Fri, 16 May 2003 13:04:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "He", "Lianyi", "" ], [ "Bian", "Guang", "" ], [ "Liao", "Jinfeng", "" ], [ "Zhuang", "Pengfei", "" ] ]
Quark deconfinement phase transition at finite temperature and density is investigated in the frame of quantum mechanics. By solving the Schr\"odinger equation for a heavy quark in a thermal mean field, we calculate the quark probability distribution as a function of temperature and density. The confined wave function in the vacuum expands outward rapidly when the temperature and density are high enough. The obtained phase transition line agrees qualitatively with the result of lattice QCD.
hep-ph/0311055
Mauro Napsuciale
Mauro Napsuciale and Mariana Kirchbach
Avoiding superluminal propagation of higher spin waves via projectors onto W^2 invariant subspaces
14 pages, Conditionally accepted in Jour. Math. Phys
J.Math.Phys.45:4515-4523,2004
10.1063/1.1794843
null
hep-ph
null
We propose to describe higher spins as invariant subspaces of the Casimir operators of the Poincar\'{e} Group, P^{2}, and the squared Pauli-Lubanski operator, W^{2}, in a properly chosen representation, \psi(p) (in momentum space), of the Homogeneous Lorentz Group. The resulting equation of motion for any field with s\neq0 is then just a specific combination of the respective covariant projectors. We couple minimally electromagnetism to this equation and show that the corresponding wave fronts of the classical solutions propagate causally. Furthermore, for (s,0)+(0,s) representations, the formalism predicts the correct gyromagnetic factor, g_{s}=1/s. The advocated method allows to describe any higher spin without auxiliary conditions and by one covariant matrix equation alone. This master equation is only quadratic in the momenta and its dimensionality is that of \psi(p). We prove that the suggested master equation avoids the Velo-Zwanziger problem of superluminal propagation of higher spin waves and points toward a consistent description of higher spin quantum fields.
[ { "created": "Tue, 4 Nov 2003 20:11:19 GMT", "version": "v1" }, { "created": "Thu, 15 Jul 2004 22:56:58 GMT", "version": "v2" } ]
2009-09-24
[ [ "Napsuciale", "Mauro", "" ], [ "Kirchbach", "Mariana", "" ] ]
We propose to describe higher spins as invariant subspaces of the Casimir operators of the Poincar\'{e} Group, P^{2}, and the squared Pauli-Lubanski operator, W^{2}, in a properly chosen representation, \psi(p) (in momentum space), of the Homogeneous Lorentz Group. The resulting equation of motion for any field with s\neq0 is then just a specific combination of the respective covariant projectors. We couple minimally electromagnetism to this equation and show that the corresponding wave fronts of the classical solutions propagate causally. Furthermore, for (s,0)+(0,s) representations, the formalism predicts the correct gyromagnetic factor, g_{s}=1/s. The advocated method allows to describe any higher spin without auxiliary conditions and by one covariant matrix equation alone. This master equation is only quadratic in the momenta and its dimensionality is that of \psi(p). We prove that the suggested master equation avoids the Velo-Zwanziger problem of superluminal propagation of higher spin waves and points toward a consistent description of higher spin quantum fields.
1408.0654
Seyed Yaser Ayazi
Seyed Yaser Ayazi and S.Mahdi Firouzabadi
Constraining Inert Triplet Dark Matter by the LHC and FermiLAT
22 pages, 7 figures, Accepted in JCAP
JCAP 11(2014)005
10.1088/1475-7516/2014/11/005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study collider phenomenology of inert triplet scalar dark matter at the LHC. We discuss possible decay of Higgs boson to dark matter candidate and apply current experimental data for invisible Higgs decay and $R_{\gamma\gamma}$ to constrain parameter space of our model. We also investigate constraints on dark matter coming from forthcoming measurement, $R_{Z\gamma}$ and mono-Higgs production. We analytically calculate the annihilation cross section of dark matter candidate into $2\gamma$ and $Z\gamma$ and then use FermiLAT data to put constraints on parameter space of Inert Triplet Model. We found that this limit can be stronger than the constraints provided by LUX experiment for low mass DM.
[ { "created": "Mon, 4 Aug 2014 12:03:28 GMT", "version": "v1" }, { "created": "Wed, 15 Oct 2014 08:45:24 GMT", "version": "v2" } ]
2015-01-27
[ [ "Ayazi", "Seyed Yaser", "" ], [ "Firouzabadi", "S. Mahdi", "" ] ]
We study collider phenomenology of inert triplet scalar dark matter at the LHC. We discuss possible decay of Higgs boson to dark matter candidate and apply current experimental data for invisible Higgs decay and $R_{\gamma\gamma}$ to constrain parameter space of our model. We also investigate constraints on dark matter coming from forthcoming measurement, $R_{Z\gamma}$ and mono-Higgs production. We analytically calculate the annihilation cross section of dark matter candidate into $2\gamma$ and $Z\gamma$ and then use FermiLAT data to put constraints on parameter space of Inert Triplet Model. We found that this limit can be stronger than the constraints provided by LUX experiment for low mass DM.
1305.2124
Viviana Gammaldi
J. A. R. Cembranos, A. de la Cruz-Dombriz, V. Gammaldi, R. A. Lineros and A. L. Maroto
Reliability of Monte Carlo event generators for gamma ray dark matter searches
15 pages, 11 figures
JHEP 1309 (2013) 077
10.1007/JHEP09(2013)077
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the differences in the gamma ray spectra simulated by four Monte Carlo event generator packages developed in particle physics. Two different versions of PYTHIA and two of HERWIG are analyzed, namely PYTHIA 6.418 and HERWIG 6.5.10 in Fortran and PYTHIA 8.165 and HERWIG 2.6.1 in C++. For all the studied channels, the intrinsic differences between them are shown to be significative and may play an important role in misunderstanding dark matter signals.
[ { "created": "Thu, 9 May 2013 15:37:19 GMT", "version": "v1" }, { "created": "Mon, 15 Jul 2013 17:30:29 GMT", "version": "v2" }, { "created": "Wed, 7 Aug 2013 13:40:04 GMT", "version": "v3" } ]
2013-10-02
[ [ "Cembranos", "J. A. R.", "" ], [ "de la Cruz-Dombriz", "A.", "" ], [ "Gammaldi", "V.", "" ], [ "Lineros", "R. A.", "" ], [ "Maroto", "A. L.", "" ] ]
We study the differences in the gamma ray spectra simulated by four Monte Carlo event generator packages developed in particle physics. Two different versions of PYTHIA and two of HERWIG are analyzed, namely PYTHIA 6.418 and HERWIG 6.5.10 in Fortran and PYTHIA 8.165 and HERWIG 2.6.1 in C++. For all the studied channels, the intrinsic differences between them are shown to be significative and may play an important role in misunderstanding dark matter signals.
0811.0774
Markus Diehl
Markus Diehl
Transverse momentum of partons: from low to high pT
7 pages, 3 figures. Talk given at Light Cone 2008, Mulhouse, France, 7-11 July 2008
PoS LC2008:031,2008
null
DESY 08-165
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse-momentum spectra in hard processes are typically described either in terms of intrinsic transverse momentum of partons, or in terms of perturbative radiation. The relation between these descriptions is discussed for the example of semi-inclusive deep inelastic scattering, with special focus on the angular distribution of the observed hadron. This involves nontrivial theoretical issues, such as the proper definition of transverse-momentum dependent parton distributions, and has practical consequences for the description of pT spectra in phenomenology.
[ { "created": "Wed, 5 Nov 2008 16:54:51 GMT", "version": "v1" } ]
2009-02-19
[ [ "Diehl", "Markus", "" ] ]
Transverse-momentum spectra in hard processes are typically described either in terms of intrinsic transverse momentum of partons, or in terms of perturbative radiation. The relation between these descriptions is discussed for the example of semi-inclusive deep inelastic scattering, with special focus on the angular distribution of the observed hadron. This involves nontrivial theoretical issues, such as the proper definition of transverse-momentum dependent parton distributions, and has practical consequences for the description of pT spectra in phenomenology.
hep-ph/9610512
null
Luis Bento (U. Lisboa) and Rui Neves (U. Durham)
Implications of anomalous gauge boson interactions to the fermion electromagnetic moments
14 pages, LATeX, to appear in Modern Physics Letters A, some literary changes, a few notation corrections
Mod.Phys.Lett. A12 (1997) 673-684
10.1142/S0217732397000704
CFNUL/96-08
hep-ph
null
We calculate the electromagnetic fermion form-factors induced by the anomalous gauge boson interactions contained in the operators ODW and ODB. Other results regarding anomalous triple gauge boson interactions are briefly overviewed. We study the interplay between vertex corrections and gauge boson self-energies extended to the longitudinal degrees of freedom. The physical couplings to an external electromagnetic field are then derived.
[ { "created": "Mon, 28 Oct 1996 17:56:49 GMT", "version": "v1" }, { "created": "Thu, 24 Apr 1997 19:53:27 GMT", "version": "v2" } ]
2009-10-30
[ [ "Bento", "Luis", "", "U. Lisboa" ], [ "Neves", "Rui", "", "U. Durham" ] ]
We calculate the electromagnetic fermion form-factors induced by the anomalous gauge boson interactions contained in the operators ODW and ODB. Other results regarding anomalous triple gauge boson interactions are briefly overviewed. We study the interplay between vertex corrections and gauge boson self-energies extended to the longitudinal degrees of freedom. The physical couplings to an external electromagnetic field are then derived.
2302.03094
Igor Ivanov
Duanyang Zhao, Igor P. Ivanov, Roman Pasechnik, Pengming Zhang
Limiting FCNC induced by a CP symmetry of order 4
1+35 pages, 11 figures; v2: figures updated, clarifications added, matches the published version
JHEP 04 (2023) 116
10.1007/JHEP04(2023)116
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
CP4 3HDM is a three-Higgs-doublet model based on the $CP$ symmetry of order 4 (CP4). Imposing CP4 leads to remarkable connections between the scalar and Yukawa sectors and unavoidably generates tree-level flavor-changing neutral couplings (FCNC). It remains unclear whether FCNC can be sufficiently suppressed in the CP4 3HDM. In this paper, we systematically explore this issue. We first develop an efficient scanning procedure which takes the quark masses and mixing as input and expresses the FCNC matrices in terms of physical quark observables and quark rotation parameters. This procedure allows us to explore the FCNC effects for all the Yukawa sectors possible within the CP4 3HDM. We find that, out of the eight possible CP4 Yukawa sectors, only two scenarios are compatible with the $K$, $B$, $B_s$ and, in particular, $D$-meson oscillation constraints. The results of this work serve as clear guidelines for future phenomenological scans of the model.
[ { "created": "Mon, 6 Feb 2023 19:52:48 GMT", "version": "v1" }, { "created": "Fri, 28 Apr 2023 03:11:50 GMT", "version": "v2" } ]
2023-05-01
[ [ "Zhao", "Duanyang", "" ], [ "Ivanov", "Igor P.", "" ], [ "Pasechnik", "Roman", "" ], [ "Zhang", "Pengming", "" ] ]
CP4 3HDM is a three-Higgs-doublet model based on the $CP$ symmetry of order 4 (CP4). Imposing CP4 leads to remarkable connections between the scalar and Yukawa sectors and unavoidably generates tree-level flavor-changing neutral couplings (FCNC). It remains unclear whether FCNC can be sufficiently suppressed in the CP4 3HDM. In this paper, we systematically explore this issue. We first develop an efficient scanning procedure which takes the quark masses and mixing as input and expresses the FCNC matrices in terms of physical quark observables and quark rotation parameters. This procedure allows us to explore the FCNC effects for all the Yukawa sectors possible within the CP4 3HDM. We find that, out of the eight possible CP4 Yukawa sectors, only two scenarios are compatible with the $K$, $B$, $B_s$ and, in particular, $D$-meson oscillation constraints. The results of this work serve as clear guidelines for future phenomenological scans of the model.
2304.09484
Oleksandr Novak
R.I. Kholodov, O.P. Novak, M.M. Diachenko
Resonant and polarization effects in the processes of quantum electrodynamics in a strong magnetic field
283 pages, 24 figures, monograph
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
The monograph considers resonance and polarization effects in quantum electrodynamics processes that take place in a strong external magnetic field. A method for analyzing spin-polarization effects has been developed. The factorization of process cross sections in resonant conditions and the representation of these cross sections in the form of Breit-Wigner are considered. The possibility of testing these effects in modern international projects to test quantum electrodynamics in strong fields is shown.
[ { "created": "Wed, 19 Apr 2023 08:16:29 GMT", "version": "v1" } ]
2023-04-20
[ [ "Kholodov", "R. I.", "" ], [ "Novak", "O. P.", "" ], [ "Diachenko", "M. M.", "" ] ]
The monograph considers resonance and polarization effects in quantum electrodynamics processes that take place in a strong external magnetic field. A method for analyzing spin-polarization effects has been developed. The factorization of process cross sections in resonant conditions and the representation of these cross sections in the form of Breit-Wigner are considered. The possibility of testing these effects in modern international projects to test quantum electrodynamics in strong fields is shown.
2009.13534
Zhengkang Zhang
Tanner Trickle, Zhengkang Zhang, Kathryn M. Zurek
Effective Field Theory of Dark Matter Direct Detection With Collective Excitations
46 pages, 4 figures; v2: expanded operator list and revised in-medium effects, conclusions unchanged; updated reference to PhonoDark https://phonodark.caltech.edu
null
null
CALT-TH-2020-037
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a framework for computing light dark matter direct detection rates through single phonon and magnon excitations via general effective operators. Our work generalizes previous calculations focused on spin-independent interactions involving the total nucleon and electron numbers $N$ (the usual route to excite phonons) and spin-dependent interactions involving the total electron spin $S$ (the usual route to excite magnons), leading us to identify new responses involving the orbital angular momenta $L$, as well as spin-orbit couplings $L\otimes S$ in the target. All four types of responses can excite phonons, while couplings to electron's $S$ and $L$ can also excite magnons. We apply the effective field theory approach to a set of well-motivated relativistic benchmark models, including (pseudo-)scalar mediated interactions, and models where dark matter interacts via a multipole moment, such as a dark electric dipole, magnetic dipole or anapole moment. We find that couplings to point-like degrees of freedom $N$ and $S$ often dominate dark matter detection rates, implying that exotic materials with orbital $L$ order or large spin-orbit couplings $L\otimes S$ are not necessary to have strong reach to a broad class of DM models. We highlight that phonon based crystal experiments in active R&D (such as SPICE) will probe light dark matter models well beyond those having a simple spin-independent interaction, including e.g. models with dipole and anapole interactions. Lastly, we make publicly available a code, PhonoDark, which computes single phonon production rates in a wide variety of materials with the effective field theory framework.
[ { "created": "Mon, 28 Sep 2020 18:00:02 GMT", "version": "v1" }, { "created": "Tue, 19 Oct 2021 07:14:28 GMT", "version": "v2" } ]
2021-10-20
[ [ "Trickle", "Tanner", "" ], [ "Zhang", "Zhengkang", "" ], [ "Zurek", "Kathryn M.", "" ] ]
We develop a framework for computing light dark matter direct detection rates through single phonon and magnon excitations via general effective operators. Our work generalizes previous calculations focused on spin-independent interactions involving the total nucleon and electron numbers $N$ (the usual route to excite phonons) and spin-dependent interactions involving the total electron spin $S$ (the usual route to excite magnons), leading us to identify new responses involving the orbital angular momenta $L$, as well as spin-orbit couplings $L\otimes S$ in the target. All four types of responses can excite phonons, while couplings to electron's $S$ and $L$ can also excite magnons. We apply the effective field theory approach to a set of well-motivated relativistic benchmark models, including (pseudo-)scalar mediated interactions, and models where dark matter interacts via a multipole moment, such as a dark electric dipole, magnetic dipole or anapole moment. We find that couplings to point-like degrees of freedom $N$ and $S$ often dominate dark matter detection rates, implying that exotic materials with orbital $L$ order or large spin-orbit couplings $L\otimes S$ are not necessary to have strong reach to a broad class of DM models. We highlight that phonon based crystal experiments in active R&D (such as SPICE) will probe light dark matter models well beyond those having a simple spin-independent interaction, including e.g. models with dipole and anapole interactions. Lastly, we make publicly available a code, PhonoDark, which computes single phonon production rates in a wide variety of materials with the effective field theory framework.
2301.07833
Naoki Yamatsu
Shuichiro Funatsu, Hisaki Hatanaka, Yuta Orikasa, Naoki Yamatsu
Single Higgs Boson Production at Electron-Positron Colliders in Gauge-Higgs Unification
34 pages, 9 tables, 11 figures; some comments and references added; Sec. 3 moved to Appendix A; accepted for publication in Physical Review D
null
10.1103/PhysRevD.107.075030
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We examine contributions to single Higgs boson production processes via $Z'$ and $W'$ bosons in the $SU(3)_C\times SO(5)_W\times U(1)_X$ gauge-Higgs unification (GHU) model. In particular, we analyze the cross sections of three single Higgs boson production processes $e^-e^+\to Zh$, $e^-e^+\to \nu\bar{\nu}h$, and $e^-e^+\to e^-e^+h$ in the SM and the GHU model. For the Higgs strahlung process $e^-e^+\to Zh$, we show that for a parameter region satisfying the current experimental constraints, a maximum deviation from the SM is about up to 6% for the center-of-mass energy of the initial electron and positron $\sqrt{s}=250$ GeV and that from the SM is about up to 20% for $\sqrt{s}=500$ GeV, depending on the initial polarization of electron and positron. The deviation from the SM is monotonically increasing with respect to $\sqrt{s}$ for $\sqrt{s}\lesssim 1$ TeV. By using the Higgs strahlung process, it is possible to explore up to the region of tens of TeV in terms of the Kaluza-Klein (KK) mass. We also show that the sign of the bulk mass of a lepton multiplet in the GHU model can be determined by examining the deviation of the left-right symmetry of the $e^-e^+\to Zh$ process from the SM. The contributions to the cross sections of the $e^-e^+\to \nu\bar{\nu}h$ and $e^-e^+\to e^-e^+h$ processes via the $Z'$ and $W'$ bosons are relatively small compared to that for $e^-e^+\to Zh$ at least for $\sqrt{s}\leq 1$ TeV. As is the same as in the SM, the $e^-e^+\to\nu\bar{\nu}h$ process gives a main contribution to the single Higgs boson production processes for $\sqrt{s}\gtrsim 500$ GeV, but large deviations from the SM are only observed on energy scales close to the masses of the first KK gauge bosons or higher.
[ { "created": "Thu, 19 Jan 2023 00:31:09 GMT", "version": "v1" }, { "created": "Wed, 5 Apr 2023 23:21:10 GMT", "version": "v2" } ]
2023-05-10
[ [ "Funatsu", "Shuichiro", "" ], [ "Hatanaka", "Hisaki", "" ], [ "Orikasa", "Yuta", "" ], [ "Yamatsu", "Naoki", "" ] ]
We examine contributions to single Higgs boson production processes via $Z'$ and $W'$ bosons in the $SU(3)_C\times SO(5)_W\times U(1)_X$ gauge-Higgs unification (GHU) model. In particular, we analyze the cross sections of three single Higgs boson production processes $e^-e^+\to Zh$, $e^-e^+\to \nu\bar{\nu}h$, and $e^-e^+\to e^-e^+h$ in the SM and the GHU model. For the Higgs strahlung process $e^-e^+\to Zh$, we show that for a parameter region satisfying the current experimental constraints, a maximum deviation from the SM is about up to 6% for the center-of-mass energy of the initial electron and positron $\sqrt{s}=250$ GeV and that from the SM is about up to 20% for $\sqrt{s}=500$ GeV, depending on the initial polarization of electron and positron. The deviation from the SM is monotonically increasing with respect to $\sqrt{s}$ for $\sqrt{s}\lesssim 1$ TeV. By using the Higgs strahlung process, it is possible to explore up to the region of tens of TeV in terms of the Kaluza-Klein (KK) mass. We also show that the sign of the bulk mass of a lepton multiplet in the GHU model can be determined by examining the deviation of the left-right symmetry of the $e^-e^+\to Zh$ process from the SM. The contributions to the cross sections of the $e^-e^+\to \nu\bar{\nu}h$ and $e^-e^+\to e^-e^+h$ processes via the $Z'$ and $W'$ bosons are relatively small compared to that for $e^-e^+\to Zh$ at least for $\sqrt{s}\leq 1$ TeV. As is the same as in the SM, the $e^-e^+\to\nu\bar{\nu}h$ process gives a main contribution to the single Higgs boson production processes for $\sqrt{s}\gtrsim 500$ GeV, but large deviations from the SM are only observed on energy scales close to the masses of the first KK gauge bosons or higher.
hep-ph/0610056
Alireza Haghpayma
Alireza Haghpayma
Diquark Approach to Calculating the Mass and Stability of H - Dibaryon
2 pages
null
null
null
hep-ph
null
By using of vector diquark ideas in the chiral limit diquark correlations in the relativistic region and imposing HF interactions between quarks in a vector diquark we calculated the mass of H-dibaryon, also by using of tunneling method we simultaneously calculated its decay width.
[ { "created": "Wed, 4 Oct 2006 20:03:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Haghpayma", "Alireza", "" ] ]
By using of vector diquark ideas in the chiral limit diquark correlations in the relativistic region and imposing HF interactions between quarks in a vector diquark we calculated the mass of H-dibaryon, also by using of tunneling method we simultaneously calculated its decay width.
1711.02083
Thomas Cridge
Francesco Coradeschi, Thomas Cridge
reSolve - A Transverse Momentum Resummation Tool
60 pages, 35 figures
Comput.Phys.Commun. 238 (2019) 262-294
10.1016/j.cpc.2018.11.024
DAMTP-2018-25
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this note, we introduce the new tool reSolve, a Monte Carlo differential cross-section and parton-level event generator whose main purpose is to add transverse momentum resummation to a general class of inclusive processes at hadron colliders, namely all those which do not involve hadrons or jets in the measured final state. This documentation refers to the first main version release, which will form the basis for continued developments, consequently it only implements the key features of those we plan to ultimately include. This article acts as a manual for the program; describing in detail its use, structure, validation and results; whilst also highlighting key aspects of the resummation formalism applied. It details the two classes of processes so far included; these are diphoton production and Drell-Yan production. A main concept behind the development of the tool is that it is a hands-on white box for the user: significant effort has been made to give the program a modular structure, making the various parts which comprise it independent of each other as much as possible and ensuring they are transparently documented, customizable and, in principle, replaceable with something that may better serve the users needs. reSolve is a new C++ program, based on an evolution of the private Fortran code 2gres, previously used for the calculations in refs. [1] and [2]; it is also influenced by the DYRes Fortran code of refs. [3] and [4]. This initial version calculates the low transverse momentum contribution to the fully differential cross-section for two main categories of processes; the inclusive production of two photons, and inclusive Drell-Yan production. In all cases resummation up to Next-to-Next-to-Leading Logarithm (NNLL) is included. We aim to extend the program to several more processes in the near future. The program is publicly available on Github.
[ { "created": "Mon, 6 Nov 2017 18:56:00 GMT", "version": "v1" }, { "created": "Fri, 15 Jun 2018 00:31:51 GMT", "version": "v2" } ]
2019-04-15
[ [ "Coradeschi", "Francesco", "" ], [ "Cridge", "Thomas", "" ] ]
In this note, we introduce the new tool reSolve, a Monte Carlo differential cross-section and parton-level event generator whose main purpose is to add transverse momentum resummation to a general class of inclusive processes at hadron colliders, namely all those which do not involve hadrons or jets in the measured final state. This documentation refers to the first main version release, which will form the basis for continued developments, consequently it only implements the key features of those we plan to ultimately include. This article acts as a manual for the program; describing in detail its use, structure, validation and results; whilst also highlighting key aspects of the resummation formalism applied. It details the two classes of processes so far included; these are diphoton production and Drell-Yan production. A main concept behind the development of the tool is that it is a hands-on white box for the user: significant effort has been made to give the program a modular structure, making the various parts which comprise it independent of each other as much as possible and ensuring they are transparently documented, customizable and, in principle, replaceable with something that may better serve the users needs. reSolve is a new C++ program, based on an evolution of the private Fortran code 2gres, previously used for the calculations in refs. [1] and [2]; it is also influenced by the DYRes Fortran code of refs. [3] and [4]. This initial version calculates the low transverse momentum contribution to the fully differential cross-section for two main categories of processes; the inclusive production of two photons, and inclusive Drell-Yan production. In all cases resummation up to Next-to-Next-to-Leading Logarithm (NNLL) is included. We aim to extend the program to several more processes in the near future. The program is publicly available on Github.
hep-ph/9808452
Richard Lebed
Richard F. Lebed
Explicit Quark-Hadron Duality in 1+1 Dimensions
4 pages, Latex (worldsci.sty), 3 eps figures. Talk presented at the Third International Conference on Quark Confinement and the Hadron Spectrum, Jefferson Lab, Newport News, Virginia, June 7-12, 1998; to appear in Proceedings
null
null
JLAB-THY-98-33
hep-ph
null
Explicit quark-hadron duality in the limit of heavy quark mass is studied using the 't Hooft model, where both partonic and hadronic amplitudes may be computed exactly. Results for weak decays of heavy mesons are presented for both standard spectator decays, where the duality limit is convincingly approached, and annihilation decays of the valence quark-antiquark pair, where the approach to asymptotic duality is much less precise.
[ { "created": "Fri, 28 Aug 1998 14:35:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lebed", "Richard F.", "" ] ]
Explicit quark-hadron duality in the limit of heavy quark mass is studied using the 't Hooft model, where both partonic and hadronic amplitudes may be computed exactly. Results for weak decays of heavy mesons are presented for both standard spectator decays, where the duality limit is convincingly approached, and annihilation decays of the valence quark-antiquark pair, where the approach to asymptotic duality is much less precise.
1502.01790
S. Ganesh
S. Ganesh and M. Mishra
pQCD approach to Charmonium regeneration in QGP at the LHC
20 pages, 15 figures; Accepted for publication in Nuclear Physics A
Nuclear Physics A 947 (2016) 38-63
10.1016/j.nuclphysa.2015.12.004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the applicability of perturbative QCD (pQCD) approach to the issue of $J/\psi$ recombination at the Large Hadron Collider (LHC), and calculate the recombination cross section for $c\bar{c}$ recombination to form $J/\psi$ as a function of temperature. The charmonium wavefunction is obtained by employing a temperature dependent phenomenological potential between the $c\bar{c}$ pair. The temperature dependent formation time of charmonium is also employed in the current work. A set of coupled rate equations is established which incorporates color screening, gluonic dissociation, collisional damping and recombination of uncorrelated $c\bar{c}$ pair in the quark-gluon plasma (QGP) medium. The final $J/\psi$ suppression, thus determined as a function of centrality is compared with the ALICE experimental data at both mid and forward rapidity and CMS experimental data at mid rapidity obtained from the Large Hadron Collider (LHC) at center of mass energy $\sqrt{s_{NN}} = 2.76$ TeV. Keywords : Color screening, Recombination, Gluonic dissociation, Collisional damping, Survival probability, pQCD, Charmonium PACS numbers : 12.38.Mh, 12.38.Gc, 25.75.Nq, 24.10.Pa
[ { "created": "Fri, 6 Feb 2015 04:33:20 GMT", "version": "v1" }, { "created": "Fri, 18 Dec 2015 10:47:18 GMT", "version": "v2" } ]
2016-02-19
[ [ "Ganesh", "S.", "" ], [ "Mishra", "M.", "" ] ]
We analyze the applicability of perturbative QCD (pQCD) approach to the issue of $J/\psi$ recombination at the Large Hadron Collider (LHC), and calculate the recombination cross section for $c\bar{c}$ recombination to form $J/\psi$ as a function of temperature. The charmonium wavefunction is obtained by employing a temperature dependent phenomenological potential between the $c\bar{c}$ pair. The temperature dependent formation time of charmonium is also employed in the current work. A set of coupled rate equations is established which incorporates color screening, gluonic dissociation, collisional damping and recombination of uncorrelated $c\bar{c}$ pair in the quark-gluon plasma (QGP) medium. The final $J/\psi$ suppression, thus determined as a function of centrality is compared with the ALICE experimental data at both mid and forward rapidity and CMS experimental data at mid rapidity obtained from the Large Hadron Collider (LHC) at center of mass energy $\sqrt{s_{NN}} = 2.76$ TeV. Keywords : Color screening, Recombination, Gluonic dissociation, Collisional damping, Survival probability, pQCD, Charmonium PACS numbers : 12.38.Mh, 12.38.Gc, 25.75.Nq, 24.10.Pa
hep-ph/9708459
A. Thomas
J. T. Londergan (Indiana University), S. A. Braendler and A. W. Thomas (University of Adelaide)
Testing Parton Charge Symmetry at HERA
8 pages, including 4 postscript figures, uses psfig
Phys.Lett.B424:185-190,1998
10.1016/S0370-2693(97)01483-4
IU/NTC 97-06 and ADP--97--31/T264
hep-ph
null
There are strong theoretical indications that the minority valence quark distributions in the nucleon may break charge symmetry by as much as 3-5%. We show that a comparison of $e^{\pm} D$ deep inelastic scattering through the charged current, for example at HERA, could provide a direct test of this effect. This measurement is also be sensitive to an intrinsic component of the strange quark sea which leads to $s \neq \bar{s}$.
[ { "created": "Tue, 26 Aug 1997 03:47:52 GMT", "version": "v1" } ]
2010-02-17
[ [ "Londergan", "J. T.", "", "Indiana University" ], [ "Braendler", "S. A.", "", "University of Adelaide" ], [ "Thomas", "A. W.", "", "University of Adelaide" ] ]
There are strong theoretical indications that the minority valence quark distributions in the nucleon may break charge symmetry by as much as 3-5%. We show that a comparison of $e^{\pm} D$ deep inelastic scattering through the charged current, for example at HERA, could provide a direct test of this effect. This measurement is also be sensitive to an intrinsic component of the strange quark sea which leads to $s \neq \bar{s}$.
0710.1054
Kai Schwenzer
Reinhard Alkofer, Christian S. Fischer, Markus Q. Huber, Kai Schwenzer
Lower dimensional Yang-Mills theory as a laboratory to study the infrared regime
7 pages, 6 figures; talk presented at Lattice 2007
POSLAT2007:329,2007
null
null
hep-ph hep-lat
null
Lattice studies of the infrared regime of gauge theories are complicated by the required extensive limits, the performed gauge fixing and the demand for high statistics. Using a general power counting scheme for the infrared limit of Landau gauge SU(N) Yang-Mills theory in arbitrary dimensions we show that the infrared behavior of Greens functions is both qualitatively and quantitatively similar in two, three and four spacetime dimensions. Therefore, lower dimensional lattice simulations can serve as a simplified laboratory to analyze the presently applied approximations and to obtain first results for higher correlation functions.
[ { "created": "Thu, 4 Oct 2007 17:02:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alkofer", "Reinhard", "" ], [ "Fischer", "Christian S.", "" ], [ "Huber", "Markus Q.", "" ], [ "Schwenzer", "Kai", "" ] ]
Lattice studies of the infrared regime of gauge theories are complicated by the required extensive limits, the performed gauge fixing and the demand for high statistics. Using a general power counting scheme for the infrared limit of Landau gauge SU(N) Yang-Mills theory in arbitrary dimensions we show that the infrared behavior of Greens functions is both qualitatively and quantitatively similar in two, three and four spacetime dimensions. Therefore, lower dimensional lattice simulations can serve as a simplified laboratory to analyze the presently applied approximations and to obtain first results for higher correlation functions.
0901.4455
Theodoros Diakonidis
Theodoros Diakonidis
Reduction Method for One-loop Tensor 5- and 6-point Integrals Revisited
Prepared for 2008 International Linear Collider Workshop (LCWS08 and ILC08), Chicago, 16-20 Nov. 2008
null
null
DESY 09-16, SFB-CPP-09-11, HEPTOOLS 09-006
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A complete analytical reduction of general one-loop Feynman integrals with five legs for tensors up to rank R=3 and six legs for tensors up to rank 4 is reviewed. An elegant formalism with extensive use of signed minors was developed for the cancellation of leading inverse Gram determinants.The resulting compact formulae allow both for a study of analytical properties and for efficient numerical programming. Here some special numerical examples are presented.
[ { "created": "Wed, 28 Jan 2009 13:30:35 GMT", "version": "v1" } ]
2009-01-29
[ [ "Diakonidis", "Theodoros", "" ] ]
A complete analytical reduction of general one-loop Feynman integrals with five legs for tensors up to rank R=3 and six legs for tensors up to rank 4 is reviewed. An elegant formalism with extensive use of signed minors was developed for the cancellation of leading inverse Gram determinants.The resulting compact formulae allow both for a study of analytical properties and for efficient numerical programming. Here some special numerical examples are presented.
1109.5682
Alessandro Strumia
Gian F. Giudice, Sergey Sibiryakov, Alessandro Strumia
Interpreting OPERA results on superluminal neutrino
21 pages, 4 figures. Final version to appear on NPB. The electroweak corrections that transfer Lorentz violation from neutrinos to electrons have now been computed finding a result in agreement with the estimate in the first version of the paper
null
10.1016/j.nuclphysb.2012.03.008
CERN-PH-TH/2011--234
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
OPERA has claimed the discovery of superluminal propagation of neutrinos. We analyze the consistency of this claim with previous tests of special relativity. We find that reconciling the OPERA measurement with information from SN1987a and from neutrino oscillations requires stringent conditions. The superluminal limit velocity of neutrinos must be nearly flavor independent, must decrease steeply in the low-energy domain, and its energy dependence must depart from a simple power law. We construct illustrative models that satisfy these conditions, by introducing Lorentz violation in a sector with light sterile neutrinos. We point out that, quite generically, electroweak quantum corrections transfer the information of superluminal neutrino properties into Lorentz violations in the electron and muon sector, in apparent conflict with experimental data.
[ { "created": "Mon, 26 Sep 2011 19:36:48 GMT", "version": "v1" }, { "created": "Wed, 14 Mar 2012 15:03:45 GMT", "version": "v2" } ]
2015-05-30
[ [ "Giudice", "Gian F.", "" ], [ "Sibiryakov", "Sergey", "" ], [ "Strumia", "Alessandro", "" ] ]
OPERA has claimed the discovery of superluminal propagation of neutrinos. We analyze the consistency of this claim with previous tests of special relativity. We find that reconciling the OPERA measurement with information from SN1987a and from neutrino oscillations requires stringent conditions. The superluminal limit velocity of neutrinos must be nearly flavor independent, must decrease steeply in the low-energy domain, and its energy dependence must depart from a simple power law. We construct illustrative models that satisfy these conditions, by introducing Lorentz violation in a sector with light sterile neutrinos. We point out that, quite generically, electroweak quantum corrections transfer the information of superluminal neutrino properties into Lorentz violations in the electron and muon sector, in apparent conflict with experimental data.
1901.09091
Ernest Ma
Ernest Ma (UC Riverside)
Scotogenic $U(1)_\chi$ Dirac Neutrinos
10 pages, 2 figures (1 new), minor revisions
null
10.1016/j.physletb.2019.05.006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The standard model of quarks and leptons is extended to include the gauge symmetry $U(1)_\chi$ which comes from $SO(10) \to SU(5) \times U(1)_\chi$. The radiative generation of Dirac neutrino masses through dark matter is discussed in two examples. One allows for light Dirac fermion dark matter. The other allows for self-interacting scalar dark matter with a light scalar mediator which decays only to two neutrinos.
[ { "created": "Fri, 25 Jan 2019 21:35:53 GMT", "version": "v1" }, { "created": "Tue, 5 Mar 2019 21:42:43 GMT", "version": "v2" } ]
2019-05-08
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
The standard model of quarks and leptons is extended to include the gauge symmetry $U(1)_\chi$ which comes from $SO(10) \to SU(5) \times U(1)_\chi$. The radiative generation of Dirac neutrino masses through dark matter is discussed in two examples. One allows for light Dirac fermion dark matter. The other allows for self-interacting scalar dark matter with a light scalar mediator which decays only to two neutrinos.
0810.2706
Tim Gershon
Tim Gershon
On the Measurement of the Unitarity Triangle Angle gamma from B^0 -> DK^{*0} Decays
5 pages, 3 figures. v2 as published
Phys.Rev.D79:051301,2009
10.1103/PhysRevD.79.051301
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay B^0 -> DK^{*0} is well-known to provide excellent potential for a precise measurement of the Unitarity Triangle angle gamma in future experiments. It is noted that the sensitivity can be significantly enhanced by studying the amplitudes relative to those of the flavour-specific decay B^0 -> D_2^{*-}K^+, which can be achieved by analyzing the B^0 -> D\pi^-K^+ Dalitz plot.
[ { "created": "Wed, 15 Oct 2008 14:24:50 GMT", "version": "v1" }, { "created": "Fri, 24 Oct 2008 11:44:51 GMT", "version": "v2" }, { "created": "Fri, 20 Mar 2009 14:18:59 GMT", "version": "v3" } ]
2009-03-24
[ [ "Gershon", "Tim", "" ] ]
The decay B^0 -> DK^{*0} is well-known to provide excellent potential for a precise measurement of the Unitarity Triangle angle gamma in future experiments. It is noted that the sensitivity can be significantly enhanced by studying the amplitudes relative to those of the flavour-specific decay B^0 -> D_2^{*-}K^+, which can be achieved by analyzing the B^0 -> D\pi^-K^+ Dalitz plot.
hep-ph/0606144
Salah Nasri
K.S. Babu, R.N. Mohapatra and S. Nasri
Post--Sphaleron Baryogenesis
13 pages, 4 figures, typos corrected, references and acknowledgment added
Phys.Rev.Lett.97:131301,2006
10.1103/PhysRevLett.97.131301
null
hep-ph
null
We present a new mechanism for generating the baryon asymmetry of the universe directly in the decay of a singlet scalar field $S_r$ with a weak scale mass and a high dimensional baryon number violating coupling. Unlike most currently popular models, this mechanism, which becomes effective after the electroweak phase transition, does not rely on the sphalerons for inducing a nonzero baryon number. CP asymmetry in $S_r$ decay arises through loop diagrams involving the exchange of $W^\pm$ gauge bosons, and is suppressed by light quark masses, leading naturally to a value of $\eta_B \sim 10^{-10}$. We show that the simplest realization of this mechanism, which uses a six quark $\Delta B=2$ operator, predicts colored scalars accessible to the LHC, and neutron--antineutron oscillation within reach of the next generation experiments.
[ { "created": "Mon, 12 Jun 2006 19:09:53 GMT", "version": "v1" }, { "created": "Tue, 27 Jun 2006 07:00:17 GMT", "version": "v2" } ]
2008-11-26
[ [ "Babu", "K. S.", "" ], [ "Mohapatra", "R. N.", "" ], [ "Nasri", "S.", "" ] ]
We present a new mechanism for generating the baryon asymmetry of the universe directly in the decay of a singlet scalar field $S_r$ with a weak scale mass and a high dimensional baryon number violating coupling. Unlike most currently popular models, this mechanism, which becomes effective after the electroweak phase transition, does not rely on the sphalerons for inducing a nonzero baryon number. CP asymmetry in $S_r$ decay arises through loop diagrams involving the exchange of $W^\pm$ gauge bosons, and is suppressed by light quark masses, leading naturally to a value of $\eta_B \sim 10^{-10}$. We show that the simplest realization of this mechanism, which uses a six quark $\Delta B=2$ operator, predicts colored scalars accessible to the LHC, and neutron--antineutron oscillation within reach of the next generation experiments.
1311.2614
Pilar Hernandez
P. Hernandez, M. Kekic, J. Lopez-Pavon
Low-scale seesaw models versus $N_{\rm eff}$
Important revision, references added, 13 pages, 5 figures
Phys. Rev. D 89, 073009 (2014)
10.1103/PhysRevD.89.073009
IFIC/13-81, SISSA 50/2013/FISI
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the contribution of the extra sterile states in generic low-scale seesaw models to extra radiation, parametrized by $N_{\rm eff}$. We find that the value of $N_{\rm eff}$ is roughly independent of the seesaw scale within a wide range. We explore the full parameter space in the case of two extra sterile states and find that these models are strongly constrained by cosmological data for any value of the seesaw scale below ${\mathcal O}(100$MeV).
[ { "created": "Mon, 11 Nov 2013 21:31:09 GMT", "version": "v1" }, { "created": "Wed, 27 Nov 2013 16:52:08 GMT", "version": "v2" } ]
2014-04-23
[ [ "Hernandez", "P.", "" ], [ "Kekic", "M.", "" ], [ "Lopez-Pavon", "J.", "" ] ]
We consider the contribution of the extra sterile states in generic low-scale seesaw models to extra radiation, parametrized by $N_{\rm eff}$. We find that the value of $N_{\rm eff}$ is roughly independent of the seesaw scale within a wide range. We explore the full parameter space in the case of two extra sterile states and find that these models are strongly constrained by cosmological data for any value of the seesaw scale below ${\mathcal O}(100$MeV).
1009.3590
Stephan Narison
G. Mennessier (CNRS-IN2P3 Montpellier), S. Narison (CNRS-IN2P3 Montpellier), X.-G. Wang (CNRS-IN2P3 Montpellier & Peking University)
The sigma and f_0(980) from K_e4+pi-pi, gamma-gamma scatterings, J/psi, phi to gamma sigma_B and D_s to l nu sigma_B
4 pages, 5 figures, 6 tables, talk given by X.-G. Wang at QCD 10 (25th anniversary) 28th june-2nd july 2010 (Montpellier - FR)
Nucl.Phys.Proc.Suppl.207-208:177-180,2010
10.1016/j.nuclphysbps.2010.10.046
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extract the pole positions, hadronic and gamma-gamma widths of sigma and f_0(980, from pi-pi and gamma-gamma scattering data using an improved analytic K-matrix model. Our results favour a large gluon component for the sigma and a \bar ss or/and gluon component for the f_0(980) but neither a large four-quark nor a molecule component. Gluonium sigma_B production from J/psi, phi radiative and D_s semi-leptonic decays are also discussed.
[ { "created": "Sat, 18 Sep 2010 22:16:19 GMT", "version": "v1" } ]
2011-02-15
[ [ "Mennessier", "G.", "", "CNRS-IN2P3 Montpellier" ], [ "Narison", "S.", "", "CNRS-IN2P3\n Montpellier" ], [ "Wang", "X. -G.", "", "CNRS-IN2P3 Montpellier & Peking University" ] ]
We extract the pole positions, hadronic and gamma-gamma widths of sigma and f_0(980, from pi-pi and gamma-gamma scattering data using an improved analytic K-matrix model. Our results favour a large gluon component for the sigma and a \bar ss or/and gluon component for the f_0(980) but neither a large four-quark nor a molecule component. Gluonium sigma_B production from J/psi, phi radiative and D_s semi-leptonic decays are also discussed.
hep-ph/9706447
David A. Kosower
Zvi Bern (UCLA), Lance Dixon (SLAC), David C. Dunbar (Swansea), David A. Kosower (Saclay)
Advanced Techniques for Multiparton Loop Calculations: A Minireview
5 pages, LaTeX/aipproc, presented at DIS '97, Chicago, IL, April 14-18, 1997
null
10.1063/1.53730
Saclay-SPhT/T97-62
hep-ph
null
We present an overview of techniques developed in recent years for the efficient calculation of one-loop multiparton amplitudes, in particular those relying on unitarity and collinear factorization.
[ { "created": "Sun, 22 Jun 1997 06:31:46 GMT", "version": "v1" } ]
2009-10-30
[ [ "Bern", "Zvi", "", "UCLA" ], [ "Dixon", "Lance", "", "SLAC" ], [ "Dunbar", "David C.", "", "Swansea" ], [ "Kosower", "David A.", "", "Saclay" ] ]
We present an overview of techniques developed in recent years for the efficient calculation of one-loop multiparton amplitudes, in particular those relying on unitarity and collinear factorization.
hep-ph/0107004
Christian Y. Cardall
Christian Y. Cardall
Theory of Neutrino Flavor Mixing
18 pages. Written contribution to the proceedings of ``Frontiers of Contemporary Physics--II,'' held March 5-10, 2001 at Vanderbilt University, Nashville, Tennessee
null
null
null
hep-ph
null
The depth of our theoretical understanding of neutrino flavor mixing should match the importance of this phenomenon as a herald of long-awaited empirical challenges to the standard model of particle physics. After reviewing the familiar, simplified quantum mechanical model and its flaws, I sketch the deeper understanding of both vacuum and matter-enhanced flavor mixing that is found in the framework of scattering theory. While the simplified model gives the ``correct answer'' for atmospheric, solar, and accelerator/reactor neutrino phenomena, I argue that a key insight from the deeper picture will simplify the treatment of neutrino transport in astrophysical environments---supernovae, for example---in which neutrinos play a dynamically important role.
[ { "created": "Sat, 30 Jun 2001 20:11:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cardall", "Christian Y.", "" ] ]
The depth of our theoretical understanding of neutrino flavor mixing should match the importance of this phenomenon as a herald of long-awaited empirical challenges to the standard model of particle physics. After reviewing the familiar, simplified quantum mechanical model and its flaws, I sketch the deeper understanding of both vacuum and matter-enhanced flavor mixing that is found in the framework of scattering theory. While the simplified model gives the ``correct answer'' for atmospheric, solar, and accelerator/reactor neutrino phenomena, I argue that a key insight from the deeper picture will simplify the treatment of neutrino transport in astrophysical environments---supernovae, for example---in which neutrinos play a dynamically important role.
1512.03136
Cesar Fernandez-Ramirez
Cesar Fernandez-Ramirez, Igor V. Danilkin, Vincent Mathieu, Adam P. Szczepaniak
Understanding the Nature of $\Lambda (1405)$ through Regge Physics
null
Phys. Rev. D 93, 074015 (2016)
10.1103/PhysRevD.93.074015
JLAB-THY-15-2182
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It appears that there are two resonances with $J^P= 1/2^-$ quantum numbers in the energy region near the $\Lambda(1405)$ hyperon. The nature of these states is a topic of current debate. To provide further insight we use Regge phenomenology to access how these two resonances fit the established hyperon spectrum. We find that only one of these resonances is compatible with a three-quark state.
[ { "created": "Thu, 10 Dec 2015 04:30:52 GMT", "version": "v1" }, { "created": "Wed, 13 Apr 2016 22:45:44 GMT", "version": "v2" } ]
2016-04-20
[ [ "Fernandez-Ramirez", "Cesar", "" ], [ "Danilkin", "Igor V.", "" ], [ "Mathieu", "Vincent", "" ], [ "Szczepaniak", "Adam P.", "" ] ]
It appears that there are two resonances with $J^P= 1/2^-$ quantum numbers in the energy region near the $\Lambda(1405)$ hyperon. The nature of these states is a topic of current debate. To provide further insight we use Regge phenomenology to access how these two resonances fit the established hyperon spectrum. We find that only one of these resonances is compatible with a three-quark state.
hep-ph/9706417
D. I. Melikhov
Dmitri Melikhov
Heavy quark expansion and universal form factors in quark model
revtex, 20 pages, 3 figure
Phys.Rev. D56 (1997) 7089-7104
10.1103/PhysRevD.56.7089
null
hep-ph
null
Meson transition amplitudes of the vector, axial-vector, and tensor quark currents are analyzed within dispersion formulation of the constituent quark model. The form factors in the decay region are given by relativistic double spectral representations through the wave functions of the inital and final mesons. We perform heavy quark expansion of the quark-model mesonic matrix elements with a next-to-leading order accuracy and demonstrate that matching this expansion to the heavy-quark expansion in QCD requires subtractions in the double spectral representations for the form factors and allows fixing the subtraction terms. The Isgur-Wise function and next-to-leading order universal form factors are calculated.
[ { "created": "Thu, 19 Jun 1997 14:53:20 GMT", "version": "v1" } ]
2009-10-30
[ [ "Melikhov", "Dmitri", "" ] ]
Meson transition amplitudes of the vector, axial-vector, and tensor quark currents are analyzed within dispersion formulation of the constituent quark model. The form factors in the decay region are given by relativistic double spectral representations through the wave functions of the inital and final mesons. We perform heavy quark expansion of the quark-model mesonic matrix elements with a next-to-leading order accuracy and demonstrate that matching this expansion to the heavy-quark expansion in QCD requires subtractions in the double spectral representations for the form factors and allows fixing the subtraction terms. The Isgur-Wise function and next-to-leading order universal form factors are calculated.
hep-ph/9911361
Oscar Alfredo Sampayo
A. Guti\'errez-Rodr\'iguez and O. A. Sampayo
Detection of Charged MSSM Higgs Bosons at CERN LEP-II and NLC
Latex file and 5 figures
null
null
null
hep-ph
null
We study the possibility of detecting the charged Higgs bosons predicted in the Minimal Supersymmetric Standard Model $(H^\pm)$, with the reactions $e^{+}e^{-}\to \tau^-\bar \nu_{\tau}H^+, \tau^+\nu_\tau H^-$, using the helicity formalism. We analyze the region of parameter space $(m_{A^0}-\tan\beta)$ where $H^\pm$ could be detected in the limit when $\tan\beta$ is large. The numerical computation is done for the energie which is expected to be available at LEP-II ($\sqrt{s}=200$ GeV) and for a possible Next Linear $e^{+}e^{-}$ Collider ($\sqrt{s}=500$ GeV).
[ { "created": "Mon, 15 Nov 1999 16:24:06 GMT", "version": "v1" } ]
2016-08-15
[ [ "Gutiérrez-Rodríguez", "A.", "" ], [ "Sampayo", "O. A.", "" ] ]
We study the possibility of detecting the charged Higgs bosons predicted in the Minimal Supersymmetric Standard Model $(H^\pm)$, with the reactions $e^{+}e^{-}\to \tau^-\bar \nu_{\tau}H^+, \tau^+\nu_\tau H^-$, using the helicity formalism. We analyze the region of parameter space $(m_{A^0}-\tan\beta)$ where $H^\pm$ could be detected in the limit when $\tan\beta$ is large. The numerical computation is done for the energie which is expected to be available at LEP-II ($\sqrt{s}=200$ GeV) and for a possible Next Linear $e^{+}e^{-}$ Collider ($\sqrt{s}=500$ GeV).
0708.1121
Markus Diehl
M. Diehl and W. Kugler
Next-to-leading order corrections in exclusive meson production
50 pages, 34 figures
Eur.Phys.J.C52:933-966,2007
10.1140/epjc/s10052-007-0423-3
DESY 07-117
hep-ph
null
We analyze in detail the size of next-to-leading order corrections to hard exclusive meson production within the collinear factorization approach. Corrections to the cross section are found to be huge at small xB and substantial in typical fixed-target kinematics. With the models we take for nucleon helicity-flip distributions, the transverse target polarization asymmetry in vector meson production is strongly affected by radiative corrections, except at large xB. Its overall size is very small for rho production but can be large in the omega channel.
[ { "created": "Wed, 8 Aug 2007 11:59:29 GMT", "version": "v1" } ]
2008-11-26
[ [ "Diehl", "M.", "" ], [ "Kugler", "W.", "" ] ]
We analyze in detail the size of next-to-leading order corrections to hard exclusive meson production within the collinear factorization approach. Corrections to the cross section are found to be huge at small xB and substantial in typical fixed-target kinematics. With the models we take for nucleon helicity-flip distributions, the transverse target polarization asymmetry in vector meson production is strongly affected by radiative corrections, except at large xB. Its overall size is very small for rho production but can be large in the omega channel.
2012.02862
Ephraim Fischbach
Ephraim Fischbach, John T. Gruenwald, Dennis E. Krause, Megan H. McDuffie, Michael J. Mueterthies, Carol Y. Scarlett
Significance of Composition-Dependent Effects in Fifth-Force Searches
7 pages, 3 figures, minor changes and corrections to match published version
Physics Letters A 399 (2021) 127300
10.1016/j.physleta.2021.127300
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Indications of a possible composition-dependent fifth force, based on a reanalysis of the E\"{o}tv\"{o}s experiment, have not been supported by a number of modern experiments. Here, we argue that searching for a composition-dependent fifth force necessarily requires data from experiments in which the acceleration differences of three or more independent pairs of test samples of varying composition are determined. We suggest that a new round of fifth-force experiments is called for, in each of which three or more different pairs of samples are compared.
[ { "created": "Fri, 4 Dec 2020 21:32:33 GMT", "version": "v1" }, { "created": "Mon, 22 Mar 2021 19:55:09 GMT", "version": "v2" } ]
2021-03-24
[ [ "Fischbach", "Ephraim", "" ], [ "Gruenwald", "John T.", "" ], [ "Krause", "Dennis E.", "" ], [ "McDuffie", "Megan H.", "" ], [ "Mueterthies", "Michael J.", "" ], [ "Scarlett", "Carol Y.", "" ] ]
Indications of a possible composition-dependent fifth force, based on a reanalysis of the E\"{o}tv\"{o}s experiment, have not been supported by a number of modern experiments. Here, we argue that searching for a composition-dependent fifth force necessarily requires data from experiments in which the acceleration differences of three or more independent pairs of test samples of varying composition are determined. We suggest that a new round of fifth-force experiments is called for, in each of which three or more different pairs of samples are compared.
2204.03050
Kazem Azizi
H. Mutuk, K. Azizi
Investigation of $\Delta^0\Delta^0$ dibaryon in QCD
9 Pages, 2 Figures and 1 Table
null
10.1103/PhysRevD.105.094021
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
We study a hypothetical $\Delta^0\Delta^0$ dibaryon state by means of QCD sum rule method. We construct a scalar interpolating current to extract the mass and decay constant of this state taking into account contributions of various quark, gluon and mixed vacuum condensates. The predictions for the mass and decay constants are $m_D=2326^{+114}_{-126} ~\mathrm{MeV}$ and $f_D=2.94^{+0.30}_{-0.34}\times 10^{-4} ~\mathrm{GeV}^7$, respectively. We also made an estimation about binding energy and size of the $\Delta^0\Delta^0$ dibaryon. The obtained mass value is below the $\Delta^0\Delta^0$ threshold and may be a good dibaryon candidate for being observed experimentally.
[ { "created": "Wed, 6 Apr 2022 19:26:09 GMT", "version": "v1" }, { "created": "Mon, 2 May 2022 19:42:49 GMT", "version": "v2" }, { "created": "Sat, 14 May 2022 05:22:30 GMT", "version": "v3" } ]
2022-06-01
[ [ "Mutuk", "H.", "" ], [ "Azizi", "K.", "" ] ]
We study a hypothetical $\Delta^0\Delta^0$ dibaryon state by means of QCD sum rule method. We construct a scalar interpolating current to extract the mass and decay constant of this state taking into account contributions of various quark, gluon and mixed vacuum condensates. The predictions for the mass and decay constants are $m_D=2326^{+114}_{-126} ~\mathrm{MeV}$ and $f_D=2.94^{+0.30}_{-0.34}\times 10^{-4} ~\mathrm{GeV}^7$, respectively. We also made an estimation about binding energy and size of the $\Delta^0\Delta^0$ dibaryon. The obtained mass value is below the $\Delta^0\Delta^0$ threshold and may be a good dibaryon candidate for being observed experimentally.
1208.0773
Antonio Di Domenico
J. Bernabeu, A. Di Domenico, P. Villanueva-Perez
Direct test of time-reversal symmetry in the entangled neutral kaon system at a $\phi$-factory
null
null
10.1016/j.nuclphysb.2012.11.009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel method to perform a direct T (time reversal) symmetry test in the neutral kaon system, independent of any CP and/or CPT symmetry tests. This is based on the comparison of suitable transition probabilities, where the required interchange of in <-> out states for a given process is obtained exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a $\phi$-factory. In the time distribution between the two decays, we compare a reference transition like the one defined by the time ordered decays $(\ell^-,\pi\pi)$ with the T -conjugated one defined by $(3\pi^0, \ell^+)$. With the use of this and other T conjugated comparisons, the KLOE-2 experiment at DA$\Phi$NE could make a significant test.
[ { "created": "Fri, 3 Aug 2012 15:39:33 GMT", "version": "v1" }, { "created": "Mon, 20 Aug 2012 20:23:26 GMT", "version": "v2" } ]
2015-06-11
[ [ "Bernabeu", "J.", "" ], [ "Di Domenico", "A.", "" ], [ "Villanueva-Perez", "P.", "" ] ]
We present a novel method to perform a direct T (time reversal) symmetry test in the neutral kaon system, independent of any CP and/or CPT symmetry tests. This is based on the comparison of suitable transition probabilities, where the required interchange of in <-> out states for a given process is obtained exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs produced at a $\phi$-factory. In the time distribution between the two decays, we compare a reference transition like the one defined by the time ordered decays $(\ell^-,\pi\pi)$ with the T -conjugated one defined by $(3\pi^0, \ell^+)$. With the use of this and other T conjugated comparisons, the KLOE-2 experiment at DA$\Phi$NE could make a significant test.
hep-ph/9503494
Tamas Csorgo
T. Csorgo and B. Lorstad
Bose-Einstein Correlations for Expanding Finite Systems
5 pages, no figures, ReVTeX, uses espcrc1.sty, Quark Matter'95 conference, Nucl. Phys. A in press
Nucl.Phys. A590 (1995) 465c-468c
10.1016/0375-9474(95)00255-Y
CU-TP-684, LUNFD6/(NFFL-7106) 1995
hep-ph nucl-th
null
There are two length-scales present simultaneously in all the principal directions for three-dimensionally expanding, finite systems. These are discussed in detail for the case of a longitudinally expanding system with a transverse flow and a transverse temperature profile. For systems with large geometrical sizes we find an $m_t$-scaling for the parameters of the Bose-Einstein correlation function, which may be valid in the whole transverse mass region for certain model parameters. In this limit, the Bose-Einstein correlations view only a small part of the source. The large geometrical sizes can be inferred from a simultaneous analysis of the invariant momentum distribution and the Bose-Einstein correlation function. A preliminary analysis of the NA44 data indicates that instead of a small fireball we are observing a big and expanding snowball in $S + Pb $ reactions at CERN SPS energies.
[ { "created": "Sun, 2 Apr 1995 14:34:56 GMT", "version": "v1" } ]
2009-10-28
[ [ "Csorgo", "T.", "" ], [ "Lorstad", "B.", "" ] ]
There are two length-scales present simultaneously in all the principal directions for three-dimensionally expanding, finite systems. These are discussed in detail for the case of a longitudinally expanding system with a transverse flow and a transverse temperature profile. For systems with large geometrical sizes we find an $m_t$-scaling for the parameters of the Bose-Einstein correlation function, which may be valid in the whole transverse mass region for certain model parameters. In this limit, the Bose-Einstein correlations view only a small part of the source. The large geometrical sizes can be inferred from a simultaneous analysis of the invariant momentum distribution and the Bose-Einstein correlation function. A preliminary analysis of the NA44 data indicates that instead of a small fireball we are observing a big and expanding snowball in $S + Pb $ reactions at CERN SPS energies.
hep-ph/9909293
James M. Gelb
James M. Gelb (U.T. Arlington), S. P. Rosen (DOE)
A Mass Matrix for Atmospheric, Solar, and LSND Neutrino Oscillations
4 pages, 0 figures, minor text changes
Phys.Rev.D62:013003,2000
10.1103/PhysRevD.62.013003
null
hep-ph
null
We construct a mass matrix for the four neutrino flavors, three active and one sterile, needed to fit oscillations in all three neutrino experiments: atmospheric, solar, and LSND, simultaneously. It organizes the neutrinos into two doublets whose central values are about 1 eV apart, and whose splittings are of the order of 10^(-3) eV. Atmospheric neutrino oscillations are described as maximal mixing within the upper doublet, and solar as the same within the lower doublet. Then LSND is a weak transition from one doublet to the other. We comment on the Majorana versus Dirac nature of the active neutrinos and show that our mass matrix can be derived from an S_2 x S_2 permutation symmetry plus an equal splitting rule.
[ { "created": "Wed, 8 Sep 1999 16:13:52 GMT", "version": "v1" }, { "created": "Mon, 15 Nov 1999 22:14:41 GMT", "version": "v2" }, { "created": "Thu, 24 Feb 2000 17:50:17 GMT", "version": "v3" } ]
2011-02-07
[ [ "Gelb", "James M.", "", "U.T. Arlington" ], [ "Rosen", "S. P.", "", "DOE" ] ]
We construct a mass matrix for the four neutrino flavors, three active and one sterile, needed to fit oscillations in all three neutrino experiments: atmospheric, solar, and LSND, simultaneously. It organizes the neutrinos into two doublets whose central values are about 1 eV apart, and whose splittings are of the order of 10^(-3) eV. Atmospheric neutrino oscillations are described as maximal mixing within the upper doublet, and solar as the same within the lower doublet. Then LSND is a weak transition from one doublet to the other. We comment on the Majorana versus Dirac nature of the active neutrinos and show that our mass matrix can be derived from an S_2 x S_2 permutation symmetry plus an equal splitting rule.
1607.03939
Patricia Magalh\~aes
J.H. Alvarenga Nogueira, I. Bediaga, T. Frederico, P.C. Magalh\~aes, J. Molina Rodriguez
Suppressed $B \to PV $ CP asymmetry: CPT constraint
final version
Phys. Rev. D 94, 054028 (2016)
10.1103/PhysRevD.94.054028
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charge Parity asymmetry in charmless B meson decays is a key issue to be understood. Many theoretical calculations have been performed using short distance factorization approaches which, in general, do not take into account the CPT invariance constraint. For each channel with CP violation there is an equal amount of CP asymmetry in another channel or other channels, with an opposite sign. This happens if these channels are coupled through final state interactions (FSI). In the specific process $B\to PV$, involving one pseudo-scalar and one vector particle in the final state, we argue that the CP asymmetry, inherent from a short distance mechanism, could be suppressed due to the CPT constraint. In this case, we propose a sensitive and practical experimental method to identify even a small CP asymmetry, which provides the values for $A_{CP}$ without the need for an amplitude analysis. This method, if applied directly to data, will enable to extract the CP asymmetry information in a model independent way and check to which extend the suggested suppression due to the CPT constraint is verified.
[ { "created": "Wed, 13 Jul 2016 21:37:06 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2016 18:23:45 GMT", "version": "v2" } ]
2016-11-02
[ [ "Nogueira", "J. H. Alvarenga", "" ], [ "Bediaga", "I.", "" ], [ "Frederico", "T.", "" ], [ "Magalhães", "P. C.", "" ], [ "Rodriguez", "J. Molina", "" ] ]
Charge Parity asymmetry in charmless B meson decays is a key issue to be understood. Many theoretical calculations have been performed using short distance factorization approaches which, in general, do not take into account the CPT invariance constraint. For each channel with CP violation there is an equal amount of CP asymmetry in another channel or other channels, with an opposite sign. This happens if these channels are coupled through final state interactions (FSI). In the specific process $B\to PV$, involving one pseudo-scalar and one vector particle in the final state, we argue that the CP asymmetry, inherent from a short distance mechanism, could be suppressed due to the CPT constraint. In this case, we propose a sensitive and practical experimental method to identify even a small CP asymmetry, which provides the values for $A_{CP}$ without the need for an amplitude analysis. This method, if applied directly to data, will enable to extract the CP asymmetry information in a model independent way and check to which extend the suggested suppression due to the CPT constraint is verified.
1509.02077
Gionata Luisoni
Hans van Deurzen, Rikkert Frederix, Valentin Hirschi, Gionata Luisoni, Pierpaolo Mastrolia, Giovanni Ossola
Spin Polarisation of $t\bar{t}\gamma\gamma$ production at NLO+PS with GoSam interfaced to MadGraph5_aMC@NLO
18 pages, 15 figures, 2 tables. Version published on EPJC
Eur. Phys. J. C (2016) 76: 221
10.1140/epjc/s10052-016-4048-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an interface between the multipurpose NLO Monte Carlo tool MadGraph5_aMC@NLO and the automated one-loop amplitude generator GoSam. As a first application of this novel framework, we compute the NLO corrections to $pp \to t\bar{t}H$ and $pp \to t\bar{t}\gamma\gamma$ matched to a parton shower. In the phenomenological analyses of these processes, we focus our attention on observables which are sensitive to the polarisation of the top quarks.
[ { "created": "Mon, 7 Sep 2015 15:27:35 GMT", "version": "v1" }, { "created": "Thu, 16 Jun 2016 20:50:00 GMT", "version": "v2" }, { "created": "Tue, 18 Jul 2017 14:09:55 GMT", "version": "v3" } ]
2017-07-19
[ [ "van Deurzen", "Hans", "" ], [ "Frederix", "Rikkert", "" ], [ "Hirschi", "Valentin", "" ], [ "Luisoni", "Gionata", "" ], [ "Mastrolia", "Pierpaolo", "" ], [ "Ossola", "Giovanni", "" ] ]
We present an interface between the multipurpose NLO Monte Carlo tool MadGraph5_aMC@NLO and the automated one-loop amplitude generator GoSam. As a first application of this novel framework, we compute the NLO corrections to $pp \to t\bar{t}H$ and $pp \to t\bar{t}\gamma\gamma$ matched to a parton shower. In the phenomenological analyses of these processes, we focus our attention on observables which are sensitive to the polarisation of the top quarks.
hep-ph/0008109
Thorsten Renk
T. Renk, G. Piller and W. Weise (TU Munich)
Coherence Effects in Diffractive Electroproduction of rho Mesons from Nuclei
21 pages, 8 figures, accepted for publication in Nuclear Physics A
Nucl.Phys. A689 (2001) 869-888
10.1016/S0375-9474(00)00700-4
TUM/T39-00-7
hep-ph
null
A systematic multiple scattering formalism for vector meson electroproduction from nuclei is developed, with emphasis on the formation, propagation and hadronization scales for quark-gluon fluctuations of the virtual high-energy photon. The theory is compared to HERMES measurements of rho electroproduction on 14N. The nuclear transparency as a function of the vector meson propagation length is well reproduced.
[ { "created": "Fri, 11 Aug 2000 09:42:07 GMT", "version": "v1" }, { "created": "Fri, 8 Dec 2000 09:58:50 GMT", "version": "v2" } ]
2009-10-31
[ [ "Renk", "T.", "", "TU Munich" ], [ "Piller", "G.", "", "TU Munich" ], [ "Weise", "W.", "", "TU Munich" ] ]
A systematic multiple scattering formalism for vector meson electroproduction from nuclei is developed, with emphasis on the formation, propagation and hadronization scales for quark-gluon fluctuations of the virtual high-energy photon. The theory is compared to HERMES measurements of rho electroproduction on 14N. The nuclear transparency as a function of the vector meson propagation length is well reproduced.
2211.12920
Yugen Lin
Yu Gao, Yu Jia, Yugen Lin, Jia-Yue Zhang
New Physics Opportunities in Triangle Singularity
5 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that loop-induced processes involving new physics particles can readily satisfy Landau Equation and trigger triangular singularities at high energy colliders, leading to fully visible Standard Model final states. Four-particle vertices in new physics allow triangular singularity diagrams to evade large virtuality suppression. In addition, a $t$-channel triangular singularity can also occur in particle scattering processes that may extend to low momentum exchange. We discuss several typical scenarios in supersymmetric and extended Higgs models, then identify the singular component in the loop-integral amplitude at specific external momentum points.
[ { "created": "Wed, 23 Nov 2022 12:49:11 GMT", "version": "v1" } ]
2022-11-24
[ [ "Gao", "Yu", "" ], [ "Jia", "Yu", "" ], [ "Lin", "Yugen", "" ], [ "Zhang", "Jia-Yue", "" ] ]
We show that loop-induced processes involving new physics particles can readily satisfy Landau Equation and trigger triangular singularities at high energy colliders, leading to fully visible Standard Model final states. Four-particle vertices in new physics allow triangular singularity diagrams to evade large virtuality suppression. In addition, a $t$-channel triangular singularity can also occur in particle scattering processes that may extend to low momentum exchange. We discuss several typical scenarios in supersymmetric and extended Higgs models, then identify the singular component in the loop-integral amplitude at specific external momentum points.
2205.06712
Thomas Rink
Thomas Rink
Coherent elastic neutrino-nucleus scattering -- First constraints/observations and future potential
Contribution to the 2022 Electroweak session of the 56th Rencontres de Moriond; v2: footnote added, references updated
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The detection of coherent elastic neutrino-nucleus scattering (CE$\nu$NS) opens new possibilities for neutrino physics within and beyond the Standard Model. Following the initial discovery in 2017, several experimental attempts have emerged allowing this reaction channel to be studied with the full repertoire of modern detection technologies. As one of several reactor experiments, CONUS aims for an observation with antineutrinos emitted from the powerful $3.9$ GW$_{th}$ reactor of the nuclear power plant in Brokdorf (Germany). In particular, the application of ultra-low threshold, high-purity germanium detectors within a sophisticated shield design in close proximity to a nuclear reactor core represents an important step towards high-statistics neutrino detection with small-scale detectors. In addition to the conventional interaction, typical extensions of the Standard Model neutrino sector can be investigated with data provided from different neutrino sources and several target materials. Among these, new neutrino interactions as well as electromagnetic neutrino properties are of particular interest. This talk gives an overview of existing CE$\nu$NS results and highlights the advantage of using different neutrino sources and target materials. The example of CONUS is used to demonstrate the various capabilities of recent and future CE$\nu$NS measurements.
[ { "created": "Fri, 13 May 2022 15:33:14 GMT", "version": "v1" }, { "created": "Mon, 9 Jan 2023 10:34:46 GMT", "version": "v2" } ]
2023-01-10
[ [ "Rink", "Thomas", "" ] ]
The detection of coherent elastic neutrino-nucleus scattering (CE$\nu$NS) opens new possibilities for neutrino physics within and beyond the Standard Model. Following the initial discovery in 2017, several experimental attempts have emerged allowing this reaction channel to be studied with the full repertoire of modern detection technologies. As one of several reactor experiments, CONUS aims for an observation with antineutrinos emitted from the powerful $3.9$ GW$_{th}$ reactor of the nuclear power plant in Brokdorf (Germany). In particular, the application of ultra-low threshold, high-purity germanium detectors within a sophisticated shield design in close proximity to a nuclear reactor core represents an important step towards high-statistics neutrino detection with small-scale detectors. In addition to the conventional interaction, typical extensions of the Standard Model neutrino sector can be investigated with data provided from different neutrino sources and several target materials. Among these, new neutrino interactions as well as electromagnetic neutrino properties are of particular interest. This talk gives an overview of existing CE$\nu$NS results and highlights the advantage of using different neutrino sources and target materials. The example of CONUS is used to demonstrate the various capabilities of recent and future CE$\nu$NS measurements.
1212.6154
Sergio Pastor
Julien Lesgourgues, Sergio Pastor
Neutrino mass from Cosmology
Invited Review article for the Special Issue on Neutrino Physics, 35 pages
Adv. High Energy Phys. 2012 (2012) 608515
10.1155/2012/608515
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinos can play an important role in the evolution of the Universe, modifying some of the cosmological observables. In this contribution we summarize the main aspects of cosmological relic neutrinos and we describe how the precision of present cosmological data can be used to learn about neutrino properties, in particular their mass, providing complementary information to beta decay and neutrinoless double-beta decay experiments. We show how the analysis of current cosmological observations, such as the anisotropies of the cosmic microwave background or the distribution of large-scale structure, provides an upper bound on the sum of neutrino masses of order 1 eV or less, with very good perspectives from future cosmological measurements which are expected to be sensitive to neutrino masses well into the sub-eV range.
[ { "created": "Wed, 26 Dec 2012 10:29:45 GMT", "version": "v1" } ]
2012-12-27
[ [ "Lesgourgues", "Julien", "" ], [ "Pastor", "Sergio", "" ] ]
Neutrinos can play an important role in the evolution of the Universe, modifying some of the cosmological observables. In this contribution we summarize the main aspects of cosmological relic neutrinos and we describe how the precision of present cosmological data can be used to learn about neutrino properties, in particular their mass, providing complementary information to beta decay and neutrinoless double-beta decay experiments. We show how the analysis of current cosmological observations, such as the anisotropies of the cosmic microwave background or the distribution of large-scale structure, provides an upper bound on the sum of neutrino masses of order 1 eV or less, with very good perspectives from future cosmological measurements which are expected to be sensitive to neutrino masses well into the sub-eV range.
hep-ph/9302236
Quevedo
Luis E. Ibanez and Fernando Quevedo
Baryon Asymmetry, Supersymmetry and Gravitational Anomalies
8 pages,FTUAM-93-07 NEIP93-001, harvmac
null
10.1111/j.1749-6632.1993.tb43923.x
null
hep-ph
null
We discuss two independent issues about the baryon asymmetry of the universe. First, assuming that it is generated by an unspecified source at high temperatures, we study the effects of non-perturbative $SU(2)_W$ dynamics above the electroweak scale, in the context of supersymmetric models. We find that there is a substantial difference with the nonsupersymmetric case with the net effect of relaxing previous bounds on B and L violating interactions. In particular supersymmetry allows neutrino masses as large as 10 eV (preferred by solar neutrino and COBE data and measurable at future neutrino oscillation experiments). Second, we argue that the existence of a mixed lepton number-gravitational anomaly in the standard model will induce B-L violating interactions. These transitions would be catalized by Einstein-Yang-Mills instantons or sphalerons and could create a primordial B-L asymmetry at Planck temperatures or lower. Gravity (and the anomaly structure of the standard model) could then be the ultimate source of the baryon asymmetry. We analyze the viability of the presently known gravitational instantons and sphalerons to realize this scenario. (Talk presented by FQ at the Texas/Pascos Conference, Berkeley Dec.1992.)
[ { "created": "Tue, 9 Feb 1993 09:49:12 GMT", "version": "v1" } ]
2009-10-22
[ [ "Ibanez", "Luis E.", "" ], [ "Quevedo", "Fernando", "" ] ]
We discuss two independent issues about the baryon asymmetry of the universe. First, assuming that it is generated by an unspecified source at high temperatures, we study the effects of non-perturbative $SU(2)_W$ dynamics above the electroweak scale, in the context of supersymmetric models. We find that there is a substantial difference with the nonsupersymmetric case with the net effect of relaxing previous bounds on B and L violating interactions. In particular supersymmetry allows neutrino masses as large as 10 eV (preferred by solar neutrino and COBE data and measurable at future neutrino oscillation experiments). Second, we argue that the existence of a mixed lepton number-gravitational anomaly in the standard model will induce B-L violating interactions. These transitions would be catalized by Einstein-Yang-Mills instantons or sphalerons and could create a primordial B-L asymmetry at Planck temperatures or lower. Gravity (and the anomaly structure of the standard model) could then be the ultimate source of the baryon asymmetry. We analyze the viability of the presently known gravitational instantons and sphalerons to realize this scenario. (Talk presented by FQ at the Texas/Pascos Conference, Berkeley Dec.1992.)
1310.0820
David Nolde
David Nolde
Effects of the imaginary inflaton component in supergravity new inflation
15 pages, 4 figures
JCAP11(2013)028
10.1088/1475-7516/2013/11/028
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When models of new inflation are implemented in supergravity, the inflaton is a complex and not a real scalar field. As a complex scalar field has two independent components, supergravity models of new inflation are naturally two-field models. In this paper, we use the delta N formalism to analyse how the two-field behaviour modifies the usual single-field predictions. We find that the model reduces to the single-field limit if the inflaton mass term is sufficiently small. Otherwise, the imaginary inflaton component reduces the amplitude A_s and the spectral index n_s of the scalar curvature perturbations. However, the perturbations remain nearly Gaussian, and the reduced bispectrum f_NL is too small to be observed.
[ { "created": "Wed, 2 Oct 2013 20:00:02 GMT", "version": "v1" }, { "created": "Tue, 12 Nov 2013 15:26:42 GMT", "version": "v2" } ]
2013-11-13
[ [ "Nolde", "David", "" ] ]
When models of new inflation are implemented in supergravity, the inflaton is a complex and not a real scalar field. As a complex scalar field has two independent components, supergravity models of new inflation are naturally two-field models. In this paper, we use the delta N formalism to analyse how the two-field behaviour modifies the usual single-field predictions. We find that the model reduces to the single-field limit if the inflaton mass term is sufficiently small. Otherwise, the imaginary inflaton component reduces the amplitude A_s and the spectral index n_s of the scalar curvature perturbations. However, the perturbations remain nearly Gaussian, and the reduced bispectrum f_NL is too small to be observed.
1407.0546
Andreas Ringwald
A. Ringwald
Axions and Axion-Like Particles
8 pages, 2 figures, invited review talk at the Rencontres de Moriond EW 2014, 15-22 March 2014, La Thuile, Italy
null
null
DESY 14-108
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The physics case for axions and axion-like particles is reviewed and an overview of ongoing and near-future laboratory searches is presented.
[ { "created": "Wed, 2 Jul 2014 12:53:08 GMT", "version": "v1" } ]
2014-07-03
[ [ "Ringwald", "A.", "" ] ]
The physics case for axions and axion-like particles is reviewed and an overview of ongoing and near-future laboratory searches is presented.
hep-ph/9701230
Xuemin Jin
Xuemin Jin and Jian Tang
Chirality and Reliability of Baryon QCD Sum Rules
8 pages, ReVTeX, one figure embedded
Phys.Rev. D56 (1997) 515-518
10.1103/PhysRevD.56.515
MIT-CTP-2601
hep-ph nucl-th
null
The QCD sum-rule method has been widely used in studying various baryon properties. For a given problem, there are usually more than one sum rules and they do not work equally well. In this paper, we point out that chirality plays an important role in determining the reliability of a baryon sum rule. The contributions of positive- and negative-parity excited baryon states partially cancel each other in the chiral-odd sum rules, but add up in the chiral-even sum rules. As such, the chiral-odd sum rules are generally more reliable than the chiral-even sum rules. This allows one to identify the more reliable sum rules and use them in extracting the ground-state baryon property of interest. This is illustrated in an explicit example.
[ { "created": "Mon, 6 Jan 1997 21:44:18 GMT", "version": "v1" } ]
2009-10-30
[ [ "Jin", "Xuemin", "" ], [ "Tang", "Jian", "" ] ]
The QCD sum-rule method has been widely used in studying various baryon properties. For a given problem, there are usually more than one sum rules and they do not work equally well. In this paper, we point out that chirality plays an important role in determining the reliability of a baryon sum rule. The contributions of positive- and negative-parity excited baryon states partially cancel each other in the chiral-odd sum rules, but add up in the chiral-even sum rules. As such, the chiral-odd sum rules are generally more reliable than the chiral-even sum rules. This allows one to identify the more reliable sum rules and use them in extracting the ground-state baryon property of interest. This is illustrated in an explicit example.
hep-ph/0311097
Karol Kolodziej
Adam Biernacik, Karol Kolodziej, Alejandro Lorca and Tord Riemann
Towards high precision predictions for top quark pair production and decay at a linear collider
8 pages, 3 figures, presented by K. Kolodziej at the XXVII International Coference of Theoretical Physics "Matter to the Deepest: Recent Developments in Physics of Fundamental Interactions", Ustron, Poland, September 15-21, 2003. Changes in V2: Eqs.(8) corrected, reference 3 updated, style revtex used
Acta Phys.Polon. B34 (2003) 5487-5496
null
DESY 03-178, SFB/CPP-03-53
hep-ph
null
We report on the progress in work on improving precision of the standard model theoretical predictions for the top quark pair production and decay into six fermions at a linear collider. Two programs have been combined into a single Monte Carlo program: 'eett6f', a MC program for e+e- -> 6f, and 'topfit', a program for electroweak radiative corrections to e+e- -> t\bar t. The MC program is described and preliminary numerical results are shown.
[ { "created": "Fri, 7 Nov 2003 14:30:45 GMT", "version": "v1" }, { "created": "Fri, 30 Sep 2005 15:43:23 GMT", "version": "v2" } ]
2016-09-06
[ [ "Biernacik", "Adam", "" ], [ "Kolodziej", "Karol", "" ], [ "Lorca", "Alejandro", "" ], [ "Riemann", "Tord", "" ] ]
We report on the progress in work on improving precision of the standard model theoretical predictions for the top quark pair production and decay into six fermions at a linear collider. Two programs have been combined into a single Monte Carlo program: 'eett6f', a MC program for e+e- -> 6f, and 'topfit', a program for electroweak radiative corrections to e+e- -> t\bar t. The MC program is described and preliminary numerical results are shown.
1508.01948
Clara Peset
Clara Peset and Antonio Pineda
The Lamb shift in muonic hydrogen and the proton radius from effective field theories
34 pages, 8 figures, 1 table, 1 appendix. Minor corrections, references added. Replaced to meet journal version
null
10.1140/epja/i2015-15156-2
null
hep-ph nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We comprehensively analyse the theoretical prediction for the Lamb shift in muonic hydrogen, and the associated determination of the proton radius. We use effective field theories. This allows us to relate the proton radius with well-defined objects in quantum field theory, eliminating unnecessary model dependence. The use of effective field theories also helps us to organize the computation so that we can clearly state the parametric accuracy of the result. In this paper we review all (and check several of) the contributions to the energy shift of order $\alpha^5$, as well as those that scale like $\alpha^6\times$logarithms in the context of non-relativistic effective field theories of QED.
[ { "created": "Sat, 8 Aug 2015 19:56:12 GMT", "version": "v1" }, { "created": "Tue, 1 Dec 2015 10:12:01 GMT", "version": "v2" } ]
2016-01-20
[ [ "Peset", "Clara", "" ], [ "Pineda", "Antonio", "" ] ]
We comprehensively analyse the theoretical prediction for the Lamb shift in muonic hydrogen, and the associated determination of the proton radius. We use effective field theories. This allows us to relate the proton radius with well-defined objects in quantum field theory, eliminating unnecessary model dependence. The use of effective field theories also helps us to organize the computation so that we can clearly state the parametric accuracy of the result. In this paper we review all (and check several of) the contributions to the energy shift of order $\alpha^5$, as well as those that scale like $\alpha^6\times$logarithms in the context of non-relativistic effective field theories of QED.
1612.05934
Wen-Fei Wang
Ya Li, Ai-Jun Ma, Zhen-Jun Xiao and Wen-Fei Wang
Quasi-two-body decays $B_{(s)}\to P\rho\to P\pi\pi$ in perturbative QCD approach
13 pages, 1 figure
Phys. Rev. D 95, 056008 (2017)
10.1103/PhysRevD.95.056008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we calculate the $CP$-averaged branching ratios and the direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)} \to P (\rho \to) \pi\pi$ by employing the perturbative QCD (PQCD) approach (here $P$ stands for a light pseudoscalar meson $\pi, K, \eta$ or $\eta^{\prime}$). The vector current time-like form factor $F_{\pi}$, which contains the final state interactions between the pion pair in the resonant region associated with the $P$-wave states $\rho(770)$ along with the two-pion distribution amplitudes, are employed to describe the interactions between the $\rho$ and the pion pair under the hypothesis of the conserved vector current. We found that (a) the PQCD predictions for the branching ratios and the direct $CP$-violating asymmetries for most considered $B_{(s)} \to P (\rho \to) \pi\pi$ decays agree with currently available data within errors; (b) for ${\cal B}(B \to \pi^0 \rho^0 \to \pi^0(\pi^+ \pi^-)$, the PQCD prediction is much smaller than the measured one; and (c) for $B^+ \to \pi^+(\rho^0\to)\pi^+ \pi^-$ decay mode, we found a negative $CP$ asymmetry $(-27.5^{+3.0}_{-3.7})\%$, which agrees with other theoretical predictions but different in sign from those as reported by BaBar and LHCb Collaboration.
[ { "created": "Sun, 18 Dec 2016 15:41:03 GMT", "version": "v1" }, { "created": "Fri, 23 Dec 2016 06:13:23 GMT", "version": "v2" }, { "created": "Tue, 7 Mar 2017 09:17:28 GMT", "version": "v3" } ]
2017-09-14
[ [ "Li", "Ya", "" ], [ "Ma", "Ai-Jun", "" ], [ "Xiao", "Zhen-Jun", "" ], [ "Wang", "Wen-Fei", "" ] ]
In this work, we calculate the $CP$-averaged branching ratios and the direct $CP$-violating asymmetries of the quasi-two-body decays $B_{(s)} \to P (\rho \to) \pi\pi$ by employing the perturbative QCD (PQCD) approach (here $P$ stands for a light pseudoscalar meson $\pi, K, \eta$ or $\eta^{\prime}$). The vector current time-like form factor $F_{\pi}$, which contains the final state interactions between the pion pair in the resonant region associated with the $P$-wave states $\rho(770)$ along with the two-pion distribution amplitudes, are employed to describe the interactions between the $\rho$ and the pion pair under the hypothesis of the conserved vector current. We found that (a) the PQCD predictions for the branching ratios and the direct $CP$-violating asymmetries for most considered $B_{(s)} \to P (\rho \to) \pi\pi$ decays agree with currently available data within errors; (b) for ${\cal B}(B \to \pi^0 \rho^0 \to \pi^0(\pi^+ \pi^-)$, the PQCD prediction is much smaller than the measured one; and (c) for $B^+ \to \pi^+(\rho^0\to)\pi^+ \pi^-$ decay mode, we found a negative $CP$ asymmetry $(-27.5^{+3.0}_{-3.7})\%$, which agrees with other theoretical predictions but different in sign from those as reported by BaBar and LHCb Collaboration.
2311.04988
Eamonn Weitz
Eamonn Weitz
Theoretical Developments for Jets in Heavy-Ion Collisions
PhD thesis, SUBATECH, Nantes Universit\'e, 144 pages
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
The quark-gluon plasma (QGP) is an exotic phase of matter, composed of deconfined quarks and gluons and is briefly created in heavy-ion collisions (HIC) at the LHC and at the RHIC. High-energy, self-collimated structures of final-state particles also created in HIC, called jets, probe the QGP, piercing through it on their way to the particle detector. Quantum field theory at finite temperature or thermal field theory, is then an extremely powerful tool, capable of analytically quantifying how such a high-energy object interacts with a weakly coupled thermal bath. In this thesis, we work towards the computation of corrections to two quantities, which dictate how jets are quenched by the QGP. The first being the transverse momentum broadening coefficient, which describes how the jet diffuses in transverse momentum space through its interaction with the medium. We focus on the computation of logarithmically enhanced corrections, carefully showing how the thermal scale affects the logarithmic phase space. The second is the asymptotic mass, which can be thought of as a shift in the jet dispersion relation as it undergoes forward scattering with the medium. We complete a matching calculation, which rids the mass' classical corrections of any unphysical divergences, while also beginning the completion of its full two-loop, quantum corrections.
[ { "created": "Wed, 8 Nov 2023 19:06:28 GMT", "version": "v1" } ]
2023-11-10
[ [ "Weitz", "Eamonn", "" ] ]
The quark-gluon plasma (QGP) is an exotic phase of matter, composed of deconfined quarks and gluons and is briefly created in heavy-ion collisions (HIC) at the LHC and at the RHIC. High-energy, self-collimated structures of final-state particles also created in HIC, called jets, probe the QGP, piercing through it on their way to the particle detector. Quantum field theory at finite temperature or thermal field theory, is then an extremely powerful tool, capable of analytically quantifying how such a high-energy object interacts with a weakly coupled thermal bath. In this thesis, we work towards the computation of corrections to two quantities, which dictate how jets are quenched by the QGP. The first being the transverse momentum broadening coefficient, which describes how the jet diffuses in transverse momentum space through its interaction with the medium. We focus on the computation of logarithmically enhanced corrections, carefully showing how the thermal scale affects the logarithmic phase space. The second is the asymptotic mass, which can be thought of as a shift in the jet dispersion relation as it undergoes forward scattering with the medium. We complete a matching calculation, which rids the mass' classical corrections of any unphysical divergences, while also beginning the completion of its full two-loop, quantum corrections.
1605.05718
Diego Guadagnoli
Diego Guadagnoli, Dmitri Melikhov and Meril Reboud
More Lepton Flavor Violating Observables for LHCb's Run 2
14 pages, 2 figures. v4: some typos corrected. Such corrections are not implemented in the journal version
null
10.1016/j.physletb.2016.07.028
LAPTH-023/16
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The R_K measurement by LHCb suggests non-standard lepton non-universality (LNU) to occur in b -> s l+ l- transitions, with effects in muons rather than electrons. A number of other measurements of b -> s l+ l- transitions by LHCb and B-factories display disagreement with the SM predictions and, remarkably, these discrepancies are consistent in magnitude and sign with the R_K effect. Non-standard LNU suggests non-standard lepton flavor violation (LFV) as well, for example in B -> K l l' and B_s -> l l'. There are good reasons to expect that the new effects may be larger for generations closer to the third one. In this case, the B_s -> mu e decay may be the most difficult to reach experimentally. We propose and study in detail the radiative counterpart of this decay, namely B_s -> mu e gamma, whereby the chiral-suppression factor is replaced by a factor of order alpha/pi. A measurement of this mode would be sensitive to the same physics as the purely leptonic LFV decay and, depending on experimental efficiencies, it may be more accessible. A realistic expectation is a factor of two improvement in statistics for either of the B_{d,s} modes.
[ { "created": "Wed, 18 May 2016 19:45:56 GMT", "version": "v1" }, { "created": "Thu, 26 May 2016 07:59:15 GMT", "version": "v2" }, { "created": "Wed, 20 Jul 2016 15:13:34 GMT", "version": "v3" }, { "created": "Fri, 14 Oct 2016 08:04:29 GMT", "version": "v4" } ]
2016-10-17
[ [ "Guadagnoli", "Diego", "" ], [ "Melikhov", "Dmitri", "" ], [ "Reboud", "Meril", "" ] ]
The R_K measurement by LHCb suggests non-standard lepton non-universality (LNU) to occur in b -> s l+ l- transitions, with effects in muons rather than electrons. A number of other measurements of b -> s l+ l- transitions by LHCb and B-factories display disagreement with the SM predictions and, remarkably, these discrepancies are consistent in magnitude and sign with the R_K effect. Non-standard LNU suggests non-standard lepton flavor violation (LFV) as well, for example in B -> K l l' and B_s -> l l'. There are good reasons to expect that the new effects may be larger for generations closer to the third one. In this case, the B_s -> mu e decay may be the most difficult to reach experimentally. We propose and study in detail the radiative counterpart of this decay, namely B_s -> mu e gamma, whereby the chiral-suppression factor is replaced by a factor of order alpha/pi. A measurement of this mode would be sensitive to the same physics as the purely leptonic LFV decay and, depending on experimental efficiencies, it may be more accessible. A realistic expectation is a factor of two improvement in statistics for either of the B_{d,s} modes.
1608.01991
Oleksandr Koshchii
O. Koshchii, A. Afanasev
Contribution of \sigma-meson exchange to elastic lepton-proton scattering
8 pages, 5 figures, minor corrections
Phys. Rev. D 94, 116007 (2016)
10.1103/PhysRevD.94.116007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton mass effects play a decisive role in description of elastic lepton-proton scattering when the beam's energy is comparable to the mass of the lepton. The future MUSE experiment, which is devised to solve the "Proton Radius Puzzle", is going to cover the corresponding kinematic region for a scattering of muons by a proton target. We anticipate that helicity-flip meson exchanges will make a difference in comparison of elastic electron-proton versus muon-proton scattering in MUSE. In this article, we estimate the $\sigma$ meson exchange contribution in the $t$-channel. This contribution, mediated by two-photon coupling of $\sigma$, is calculated to be at most $\sim 0.1 \%$ for muons in the kinematics of MUSE and it is about 3 orders in magnitude larger than for electrons because of the lepton-mass difference.
[ { "created": "Sat, 6 Aug 2016 21:36:11 GMT", "version": "v1" }, { "created": "Mon, 12 Dec 2016 22:39:08 GMT", "version": "v2" } ]
2016-12-14
[ [ "Koshchii", "O.", "" ], [ "Afanasev", "A.", "" ] ]
Lepton mass effects play a decisive role in description of elastic lepton-proton scattering when the beam's energy is comparable to the mass of the lepton. The future MUSE experiment, which is devised to solve the "Proton Radius Puzzle", is going to cover the corresponding kinematic region for a scattering of muons by a proton target. We anticipate that helicity-flip meson exchanges will make a difference in comparison of elastic electron-proton versus muon-proton scattering in MUSE. In this article, we estimate the $\sigma$ meson exchange contribution in the $t$-channel. This contribution, mediated by two-photon coupling of $\sigma$, is calculated to be at most $\sim 0.1 \%$ for muons in the kinematics of MUSE and it is about 3 orders in magnitude larger than for electrons because of the lepton-mass difference.
2212.06535
Pengyu Niu
PengYu Niu, Zhenyu Zhang, Qian Wang and Meng-Lin Du
The third peak structure in the double $J/\psi$ spectrum
15 pages, 5 figures; accepted by Science Bulletin
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, the CMS and ATLAS collaborations have reported their $J/\psi J/\psi $ and $J/\psi \psi^\prime$ invariant mass distributions, respectively, for searching for fully charmed tetraquarks. Both of them reported the existence of a peak structure around $7.2~\gev$. In this article, we exhibit the role of the $\eta_c(2S)\eta_c(2S)$ channel, which is close to this peak position, by studying the $J/\psi J/\psi $ and $J/\psi \psi^\prime$ invariant mass distributions for the potential quantum numbers $J^{PC}=0^{++}$ or $2^{++}$ by considering both the coherence and incoherence with the background contribution. All these frameworks can describe the experimental data very well, however with different pole structures. For instance, in the case of $2^{++}$ description of these structures, there always exists a pole slightly below the $J/\psi J/\psi$ threshold. For the $0^{++}$ case, a similar pole can also be found below the $J/\psi J/\psi$ threshold however with a much lower mass. More importantly, the number of the poles is found to be case-dependent. For the $0^{++}$ ($2^{++}$) case, the peak structure around $7.2~\gev$ can (cannot) be produced due to the presence (absence) of the $\eta_c(2S)\eta_c(2S)$ channel. Although the pole positions are case-dependent, the relation between the peak structure in the $J/\psi J/\psi$ invariant mass distribution and the dip structure in the $J/\psi \psi^\prime$ invariant mass distribution around $7.2~\gev$ is unambiguous. We suggest experimentalists to detailed scan both the $J/\psi J/\psi$ and the $J/\psi \psi^\prime$ invariant mass distributions, especially around $7.2~\gev$ to probe the nature of the third fully charmed state.
[ { "created": "Tue, 13 Dec 2022 12:40:27 GMT", "version": "v1" }, { "created": "Tue, 11 Apr 2023 12:51:37 GMT", "version": "v2" } ]
2023-04-12
[ [ "Niu", "PengYu", "" ], [ "Zhang", "Zhenyu", "" ], [ "Wang", "Qian", "" ], [ "Du", "Meng-Lin", "" ] ]
Recently, the CMS and ATLAS collaborations have reported their $J/\psi J/\psi $ and $J/\psi \psi^\prime$ invariant mass distributions, respectively, for searching for fully charmed tetraquarks. Both of them reported the existence of a peak structure around $7.2~\gev$. In this article, we exhibit the role of the $\eta_c(2S)\eta_c(2S)$ channel, which is close to this peak position, by studying the $J/\psi J/\psi $ and $J/\psi \psi^\prime$ invariant mass distributions for the potential quantum numbers $J^{PC}=0^{++}$ or $2^{++}$ by considering both the coherence and incoherence with the background contribution. All these frameworks can describe the experimental data very well, however with different pole structures. For instance, in the case of $2^{++}$ description of these structures, there always exists a pole slightly below the $J/\psi J/\psi$ threshold. For the $0^{++}$ case, a similar pole can also be found below the $J/\psi J/\psi$ threshold however with a much lower mass. More importantly, the number of the poles is found to be case-dependent. For the $0^{++}$ ($2^{++}$) case, the peak structure around $7.2~\gev$ can (cannot) be produced due to the presence (absence) of the $\eta_c(2S)\eta_c(2S)$ channel. Although the pole positions are case-dependent, the relation between the peak structure in the $J/\psi J/\psi$ invariant mass distribution and the dip structure in the $J/\psi \psi^\prime$ invariant mass distribution around $7.2~\gev$ is unambiguous. We suggest experimentalists to detailed scan both the $J/\psi J/\psi$ and the $J/\psi \psi^\prime$ invariant mass distributions, especially around $7.2~\gev$ to probe the nature of the third fully charmed state.
2209.01058
Per Grafstrom
Per Grafstrom
Comments on low mass dissociation at the LHC in the context of the discrepancy between the ATLAS and TOTEM measurements of $\sigma_{tot}$
11 pages, 5 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cross section for low mass dissociation at LHC energies is estimated in a partly data driven approach. The result is compared to the Monte Carlo estimate from the QGSJET-II-03 model used by the TOTEM experiment in the determination of $\sigma_{tot}$ via the luminosity-independent method. Significant differences are found and possible consequences are explored and discussed.
[ { "created": "Fri, 2 Sep 2022 13:50:19 GMT", "version": "v1" } ]
2022-09-05
[ [ "Grafstrom", "Per", "" ] ]
The cross section for low mass dissociation at LHC energies is estimated in a partly data driven approach. The result is compared to the Monte Carlo estimate from the QGSJET-II-03 model used by the TOTEM experiment in the determination of $\sigma_{tot}$ via the luminosity-independent method. Significant differences are found and possible consequences are explored and discussed.
hep-ph/9902426
Marco Stratmann
S. Kretzer (Dortmund Univ.), M. Stratmann (Durham Univ.)
Next-to-Leading Order QCD Corrections to Charged Current Charm Production and the Unpolarized and Polarized Strange Sea at HERA
34 pages, LaTeX, 7 eps figures, uses amssymb, axodraw (included) and epsfig styles
Eur.Phys.J.C10:107-119,1999
10.1007/s100529900116
DO-TH 99/02, DTP/99/16
hep-ph
null
Charged current charm and D meson production is studied in detail as a means of determining the unpolarized and polarized strange sea densities at HERA. All analyses are performed in next-to-leading order QCD, including a calculation of the so far unknown spin-dependent MSbar coefficient functions up to O(alpha_s). It is shown that a decent measurement is possible in the unpolarized case, provided a sufficient luminosity can be reached in the future, while for longitudinally polarized beams it appears to be extremely challenging due to limitations imposed on the expected statistical accuracy by the charm detection efficiency.
[ { "created": "Mon, 22 Feb 1999 15:47:29 GMT", "version": "v1" } ]
2011-09-13
[ [ "Kretzer", "S.", "", "Dortmund Univ." ], [ "Stratmann", "M.", "", "Durham Univ." ] ]
Charged current charm and D meson production is studied in detail as a means of determining the unpolarized and polarized strange sea densities at HERA. All analyses are performed in next-to-leading order QCD, including a calculation of the so far unknown spin-dependent MSbar coefficient functions up to O(alpha_s). It is shown that a decent measurement is possible in the unpolarized case, provided a sufficient luminosity can be reached in the future, while for longitudinally polarized beams it appears to be extremely challenging due to limitations imposed on the expected statistical accuracy by the charm detection efficiency.