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hep-ph/0405226
Antal Jakovac
A. Jakovac, Zs. Szep
Renormalization and resummation in finite temperature field theories
10 pages, 4 figures, revtex4
Phys.Rev. D71 (2005) 105001
10.1103/PhysRevD.71.105001
null
hep-ph
null
Resummation, ie. reorganization of perturbative series, can result in an inconsistent perturbation theory, unless the counterterms are reorganized in an appropriate way. In this paper two methods are presented for resummation of counterterms: one is a direct method where the necessary counterterms are constructed order by order; the other is a general one, based on renormalization group arguments. We demonstrate at one hand that, in mass independent schemes, mass resummation can be performed by gap equations renormalized prior to the substitution of the resummed mass for its argument. On the other hand it is shown that any (momentum-independent) form of mass and coupling constant resummation is compatible with renormalization, and one can explicitly construct the corresponding counterterms.
[ { "created": "Mon, 24 May 2004 08:50:59 GMT", "version": "v1" } ]
2009-11-10
[ [ "Jakovac", "A.", "" ], [ "Szep", "Zs.", "" ] ]
Resummation, ie. reorganization of perturbative series, can result in an inconsistent perturbation theory, unless the counterterms are reorganized in an appropriate way. In this paper two methods are presented for resummation of counterterms: one is a direct method where the necessary counterterms are constructed order by order; the other is a general one, based on renormalization group arguments. We demonstrate at one hand that, in mass independent schemes, mass resummation can be performed by gap equations renormalized prior to the substitution of the resummed mass for its argument. On the other hand it is shown that any (momentum-independent) form of mass and coupling constant resummation is compatible with renormalization, and one can explicitly construct the corresponding counterterms.
hep-ph/9710261
Andreas Schaefer
I.V. Musatov (Old Dominion University, Norfolk, USA), O.V. Teryaev, (Bogoliubov Laboratory of Theoretical Physics, Dubna, Russia) and A. Sch\"afer (Universit\"at Regensburg, Germany)
The elastic contribution to the Burkhardt -- Cottingham and Generalized Gerasimov--Drell-Hearn Sum Rules
8 pages latex and one figure
Phys.Rev. D57 (1998) 7041-7044
10.1103/PhysRevD.57.7041
null
hep-ph
null
The elastic contribution to the first moment of $g_2(x,Q^2)$ is analysed using a Drell-Yan-West type of relation and is shown to be negative. For a qualitative estimate the one-loop contributions to the polarized DIS sum rules in QED are studied. The behaviour of the generalized Gerasimov-Drell-Hearn sum rule is sensitive to infrared regularization. With a lower threshold for the gluon virtuality the relation of the generalized GDH sum rule to the Burkhardt-Cottingham sum rule is studied. We conclude that the elastic part has to be included for long range interactions but can be consistently discarded for short range interactions.
[ { "created": "Tue, 7 Oct 1997 08:30:37 GMT", "version": "v1" } ]
2009-10-30
[ [ "Musatov", "I. V.", "", "Old Dominion University, Norfolk, USA" ], [ "Teryaev", "O. V.", "", "Universität Regensburg, Germany" ], [ "Schäfer", "A.", "", "Universität Regensburg, Germany" ] ]
The elastic contribution to the first moment of $g_2(x,Q^2)$ is analysed using a Drell-Yan-West type of relation and is shown to be negative. For a qualitative estimate the one-loop contributions to the polarized DIS sum rules in QED are studied. The behaviour of the generalized Gerasimov-Drell-Hearn sum rule is sensitive to infrared regularization. With a lower threshold for the gluon virtuality the relation of the generalized GDH sum rule to the Burkhardt-Cottingham sum rule is studied. We conclude that the elastic part has to be included for long range interactions but can be consistently discarded for short range interactions.
1111.0197
Gernot Eichmann
Gernot Eichmann, Christian S. Fischer
Unified description of hadron-photon and hadron-meson scattering in the Dyson-Schwinger approach
15 pages, 6 figures
null
10.1103/PhysRevD.85.034015
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the expression for the nonperturbative coupling of a hadron to two external currents from its underlying structure in QCD. Microscopically, the action of each current is resolved to a coupling with dressed quarks. The Lorentz structure of the currents is arbitrary and thereby allows to describe the hadron's interaction with photons as well as mesons in the same framework. We analyze the ingredients of the resulting four-point functions and explore their potential to describe a variety of processes relevant in experiments. Possible applications include Compton scattering, the study of two-photon effects in hadron form factors, pion photo- and electroproduction on a nucleon, nucleon-pion or pion-pion scattering.
[ { "created": "Tue, 1 Nov 2011 13:21:13 GMT", "version": "v1" } ]
2013-05-30
[ [ "Eichmann", "Gernot", "" ], [ "Fischer", "Christian S.", "" ] ]
We derive the expression for the nonperturbative coupling of a hadron to two external currents from its underlying structure in QCD. Microscopically, the action of each current is resolved to a coupling with dressed quarks. The Lorentz structure of the currents is arbitrary and thereby allows to describe the hadron's interaction with photons as well as mesons in the same framework. We analyze the ingredients of the resulting four-point functions and explore their potential to describe a variety of processes relevant in experiments. Possible applications include Compton scattering, the study of two-photon effects in hadron form factors, pion photo- and electroproduction on a nucleon, nucleon-pion or pion-pion scattering.
1105.3333
Jose Santiago
Roberto Barcelo, Adrian Carmona, Manuel Masip, Jose Santiago
Gluon excitations in t tbar production at hadron colliders
16 pages, 6 figures
Phys.Rev.D84:014024,2011
10.1103/PhysRevD.84.014024
UG-FT-286/11,CAFPE-156/11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that a relatively light massive gluon with mass <= 1 TeV, small purely axial couplings to light quarks and sizable vector and axial couplings to the top quark can reproduce the large forward-backward asymmetry observed at the Tevatron without conflicting with the t tbar and the dijet invariant mass distributions measured at the Tevatron and the LHC. We show that realistic Higgsless models with warped extra dimensions naturally fulfil all the necessary ingredients to realize this scenario. While current data is unable to discover or exclude these heavy gluons with masses 850 GeV, they should be observed at the (7 TeV) LHC with a luminosity of the order of 300 pb^{-1}.
[ { "created": "Tue, 17 May 2011 10:30:49 GMT", "version": "v1" } ]
2011-08-09
[ [ "Barcelo", "Roberto", "" ], [ "Carmona", "Adrian", "" ], [ "Masip", "Manuel", "" ], [ "Santiago", "Jose", "" ] ]
We argue that a relatively light massive gluon with mass <= 1 TeV, small purely axial couplings to light quarks and sizable vector and axial couplings to the top quark can reproduce the large forward-backward asymmetry observed at the Tevatron without conflicting with the t tbar and the dijet invariant mass distributions measured at the Tevatron and the LHC. We show that realistic Higgsless models with warped extra dimensions naturally fulfil all the necessary ingredients to realize this scenario. While current data is unable to discover or exclude these heavy gluons with masses 850 GeV, they should be observed at the (7 TeV) LHC with a luminosity of the order of 300 pb^{-1}.
2005.06381
Thomas Peitzmann
Thomas Peitzmann
Constraints of the Low-x Structure of Protons and Nuclei
6 pages, to be published in proceedings of ISMD 2019, Santa Fe
null
10.1051/epjconf/202023503001
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
I review recent developments in the study of the low-x partonic content of protons and nuclei, with a focus on the latter, as one expects possible deviations from linear QCD evolution to be most pronounced in that case. I give examples of recent theoretical descriptions of HERA measurements with a focus on the role of BFKL evolution. I then concentrate on the status and assumptions of nuclear PDFs and the possibility to use forward particle production at the LHC as further constraint, in particular measurements of open charm and the potential of electromagnetic probes.
[ { "created": "Wed, 13 May 2020 15:46:18 GMT", "version": "v1" } ]
2020-07-15
[ [ "Peitzmann", "Thomas", "" ] ]
I review recent developments in the study of the low-x partonic content of protons and nuclei, with a focus on the latter, as one expects possible deviations from linear QCD evolution to be most pronounced in that case. I give examples of recent theoretical descriptions of HERA measurements with a focus on the role of BFKL evolution. I then concentrate on the status and assumptions of nuclear PDFs and the possibility to use forward particle production at the LHC as further constraint, in particular measurements of open charm and the potential of electromagnetic probes.
hep-ph/9902225
Thomas Gehrmann
T. Gehrmann (Karlsruhe), T. Sloan (Lancaster)
Spin physics in deep inelastic scattering: Summary
6 (Latex) pages, including 1 embedded figure, uses IOP style files; Plenary talk presented at the 3rd UK Phenomenology Workshop on HERA Physics, Durham, September 1998, to be published in the Proceedings; The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ttp99/ttp99-04/ or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/webmaster/preprints/
J.Phys.G25:1527-1532,1999
10.1088/0954-3899/25/7/340
TTP99-04
hep-ph
null
The problem of our understanding of the spin structure of the nucleon has been with us since the publication of the EMC measurements of the polarised structure function of the proton in 1987. In this talk a review of the results presented in Working Group 6 at this workshop is given.
[ { "created": "Tue, 2 Feb 1999 14:03:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gehrmann", "T.", "", "Karlsruhe" ], [ "Sloan", "T.", "", "Lancaster" ] ]
The problem of our understanding of the spin structure of the nucleon has been with us since the publication of the EMC measurements of the polarised structure function of the proton in 1987. In this talk a review of the results presented in Working Group 6 at this workshop is given.
hep-ph/9702398
Carlos Alberto Salgado Lopez
J. Dias de Deus, C. Pajares and C. A. Salgado
Moment Analysis, Multiplicity Distributions and Correlations in High Energy Processes: Nucleus-Nucleus Collisions
11 pages, 2 Postscript figures
Phys.Lett. B407 (1997) 335-340
10.1016/S0370-2693(97)00677-1
US-FT/6-97
hep-ph
null
Cumulant oscillations, or $H_q$ moment oscillations, appear if the KNO multiparticle distribution decreases at large z, $z\equiv n/ <n>$, faster than the exponential, $exp(-D z^\mu)$, with $\mu > 1$. In nucleus-nucleus interactions this behaviour is related to the limitation in the average number of elementary central collisions (or average number of strings centrally produced), due to the finite number of nucleons involved. Colour deconfinement, via percolating string fusion, will drastically decrease the fraction of centrally produced strings and increase the cut-off parameter $\mu$: Moment oscillations will be displaced to smaller q and the width of the KNO distribution and forward-backward particle correlations will become smaller.
[ { "created": "Sat, 22 Feb 1997 13:48:16 GMT", "version": "v1" } ]
2009-10-30
[ [ "de Deus", "J. Dias", "" ], [ "Pajares", "C.", "" ], [ "Salgado", "C. A.", "" ] ]
Cumulant oscillations, or $H_q$ moment oscillations, appear if the KNO multiparticle distribution decreases at large z, $z\equiv n/ <n>$, faster than the exponential, $exp(-D z^\mu)$, with $\mu > 1$. In nucleus-nucleus interactions this behaviour is related to the limitation in the average number of elementary central collisions (or average number of strings centrally produced), due to the finite number of nucleons involved. Colour deconfinement, via percolating string fusion, will drastically decrease the fraction of centrally produced strings and increase the cut-off parameter $\mu$: Moment oscillations will be displaced to smaller q and the width of the KNO distribution and forward-backward particle correlations will become smaller.
0706.1284
Yi Liao
Yi Liao (Nankai U.), Ji-Yuan Liu (Nankai U.)
Long-range Electron Spin-spin Interactions from Unparticle Exchange
v1: 10 pages, no figure, 1 table; v2: Proofread version for PRL. Main changes: (1) Shortened considerably to meet the length limit by cutting some calculational details. (2) Introduction paragraphs hopefully improved. (3) Minor rewording in the text and title. There are no changes to numerical results and conclusions
Phys.Rev.Lett.99:191804,2007
10.1103/PhysRevLett.99.191804
null
hep-ph hep-ex
null
Unparticles as suggested by Georgi are identities that are not constrained by dispersion relations but are governed by their scaling dimension, d. Their coupling to particles can result in macroscopic interactions between matter, that are generally an inverse nonintegral power of distance. This is totally different from known macroscopic forces. We use the precisely measured long-ranged spin-spin interaction of electrons to constrain unparticle couplings to the electron. For 1<d<1.5 the axial vector unparticle coupling is excluded; and for 1<d<1.3 the pseudoscalar and vector couplings are also ruled out. These bounds and the ones for other ranges of d exceed or are complementary to those obtained previously from exotic positronium decays.
[ { "created": "Sat, 9 Jun 2007 03:32:06 GMT", "version": "v1" }, { "created": "Sat, 3 Nov 2007 07:53:32 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liao", "Yi", "", "Nankai U." ], [ "Liu", "Ji-Yuan", "", "Nankai U." ] ]
Unparticles as suggested by Georgi are identities that are not constrained by dispersion relations but are governed by their scaling dimension, d. Their coupling to particles can result in macroscopic interactions between matter, that are generally an inverse nonintegral power of distance. This is totally different from known macroscopic forces. We use the precisely measured long-ranged spin-spin interaction of electrons to constrain unparticle couplings to the electron. For 1<d<1.5 the axial vector unparticle coupling is excluded; and for 1<d<1.3 the pseudoscalar and vector couplings are also ruled out. These bounds and the ones for other ranges of d exceed or are complementary to those obtained previously from exotic positronium decays.
1801.05268
Shunya Takahashi
Takuya Morozumi, Yusuke Shimizu, Shunya Takahashi, and Hiroyuki Umeeda
Effective theory analysis for vector-like quark model
30 pages, 14 figures. In version 2, a typo is corrected and some references are added. We added a comment on the RG effect in the section of summary and discussion
Prog Theor Exp Phys (2018)
10.1093/ptep/pty042
HUPD1714
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a model with a down-type SU(2) singlet vector-like quark (VLQ) as a minimal extension of the standard model (SM). In this model, flavor changing neutral currents (FCNCs) arise at tree level and the unitarity of the $3\times 3$ Cabibbo-Kobayashi-Maskawa (CKM) matrix does not hold. In this paper, we constrain the FCNC coupling from $b\rightarrow s$ transitions, especially $B_s\rightarrow \mu^+\mu^-$ and $\bar{B}\rightarrow X_s\gamma$ processes. In order to analyze these processes, we derive an effective Lagrangian which is valid below the electroweak symmetry breaking scale. For this purpose, we first integrate out the VLQ field and derive an effective theory by matching Wilson coefficients up to one-loop level. Using the effective theory, we construct the effective Lagrangian for $b\rightarrow s\gamma^{(*)}$. It includes the effects of the SM quarks and the violation of the CKM unitarity. We show the constraints on the magnitude of the FCNC coupling and its phase by taking account of the current experimental data on $\Delta M_{B_s}$, $\mathrm{Br}[B_s\rightarrow\mu^+\mu^-]$, $\mathrm{Br}[\bar{B}\rightarrow X_s\gamma]$ and CKM matrix elements as well as theoretical uncertainties. We find that the constraint from the $\mathrm{Br}[B_s\rightarrow\mu^+\mu^-]$ is more stringent than that from the $\mathrm{Br}[\bar{B}\rightarrow X_s\gamma$]. We also obtain the bound for the mass of the VLQ and the strength of the Yukawa couplings related to the FCNC coupling of $b\rightarrow s$ transition. Using the CKM elements which satisfy above constraints, we show how the unitarity is violated on the complex plane.
[ { "created": "Tue, 16 Jan 2018 14:43:17 GMT", "version": "v1" }, { "created": "Mon, 12 Mar 2018 05:49:47 GMT", "version": "v2" } ]
2019-12-06
[ [ "Morozumi", "Takuya", "" ], [ "Shimizu", "Yusuke", "" ], [ "Takahashi", "Shunya", "" ], [ "Umeeda", "Hiroyuki", "" ] ]
We study a model with a down-type SU(2) singlet vector-like quark (VLQ) as a minimal extension of the standard model (SM). In this model, flavor changing neutral currents (FCNCs) arise at tree level and the unitarity of the $3\times 3$ Cabibbo-Kobayashi-Maskawa (CKM) matrix does not hold. In this paper, we constrain the FCNC coupling from $b\rightarrow s$ transitions, especially $B_s\rightarrow \mu^+\mu^-$ and $\bar{B}\rightarrow X_s\gamma$ processes. In order to analyze these processes, we derive an effective Lagrangian which is valid below the electroweak symmetry breaking scale. For this purpose, we first integrate out the VLQ field and derive an effective theory by matching Wilson coefficients up to one-loop level. Using the effective theory, we construct the effective Lagrangian for $b\rightarrow s\gamma^{(*)}$. It includes the effects of the SM quarks and the violation of the CKM unitarity. We show the constraints on the magnitude of the FCNC coupling and its phase by taking account of the current experimental data on $\Delta M_{B_s}$, $\mathrm{Br}[B_s\rightarrow\mu^+\mu^-]$, $\mathrm{Br}[\bar{B}\rightarrow X_s\gamma]$ and CKM matrix elements as well as theoretical uncertainties. We find that the constraint from the $\mathrm{Br}[B_s\rightarrow\mu^+\mu^-]$ is more stringent than that from the $\mathrm{Br}[\bar{B}\rightarrow X_s\gamma$]. We also obtain the bound for the mass of the VLQ and the strength of the Yukawa couplings related to the FCNC coupling of $b\rightarrow s$ transition. Using the CKM elements which satisfy above constraints, we show how the unitarity is violated on the complex plane.
2301.05972
Nikolaos Kidonakis
Nikolaos Kidonakis
Four-loop massive cusp anomalous dimension in QCD: a calculation from asymptotics
21 pages, 7 figures; v2 has additional study of color structures
Phys. Rev. D 107, 054006 (2023)
10.1103/PhysRevD.107.054006
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present a general method for determining the massive cusp anomalous dimension in QCD to a very high degree of accuracy using its asymptotic behavior at small and large quark velocities. I show that the method works exceedingly well at two and three loops where exact results are already known. I then present a calculation of the massive cusp anomalous dimension using its asymptotics at four loops, and I provide a detailed study of the results for different values of the number of flavors and for separate color structures. The method can be further extended and applied to higher numbers of loops.
[ { "created": "Sat, 14 Jan 2023 20:46:03 GMT", "version": "v1" }, { "created": "Thu, 2 Feb 2023 03:11:27 GMT", "version": "v2" } ]
2023-03-15
[ [ "Kidonakis", "Nikolaos", "" ] ]
I present a general method for determining the massive cusp anomalous dimension in QCD to a very high degree of accuracy using its asymptotic behavior at small and large quark velocities. I show that the method works exceedingly well at two and three loops where exact results are already known. I then present a calculation of the massive cusp anomalous dimension using its asymptotics at four loops, and I provide a detailed study of the results for different values of the number of flavors and for separate color structures. The method can be further extended and applied to higher numbers of loops.
hep-ph/0312364
Grzegorz Wilk
Oleg.V.Utyuzh and Grzegorz Wilk
BEC for photons and neutral pions
Contribution to Second Warsaw Meeting on Particle Correlations and Resonances in Heavy Ion Collisions, Warsaw, 15-18 October, 2003, Poland
Nukleonika 49 (2004) S15
null
null
hep-ph
null
The role of BEC for photons and neutral pions is briefly discussed and illustrated by means of new method of numerical modelling of BEC proposed by us recently.
[ { "created": "Mon, 29 Dec 2003 12:35:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Utyuzh", "Oleg. V.", "" ], [ "Wilk", "Grzegorz", "" ] ]
The role of BEC for photons and neutral pions is briefly discussed and illustrated by means of new method of numerical modelling of BEC proposed by us recently.
hep-ph/0605018
Naoki Yamamoto
Tetsuo Hatsuda, Motoi Tachibana, Naoki Yamamoto and Gordon Baym
New Critical Point Induced by the Axial Anomaly in Dense QCD
4 pages, 4 figures included, version to appear in Phys. Rev. Lett
Phys.Rev.Lett. 97 (2006) 122001
10.1103/PhysRevLett.97.122001
TKYNT-06-8, SAGA-HE-228
hep-ph cond-mat.other nucl-th
null
We study the interplay between chiral and diquark condensates within the framework of the Ginzburg-Landau free energy, and classify possible phase structures of two and three-flavor massless QCD. The QCD axial anomaly acts as an external field applied to the chiral condensate in a color superconductor and leads to a crossover between the broken chiral symmetry and the color superconducting phase, and, in particular, to a new critical point in the QCD phase diagram.
[ { "created": "Mon, 1 May 2006 03:16:41 GMT", "version": "v1" }, { "created": "Mon, 2 Oct 2006 08:42:41 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hatsuda", "Tetsuo", "" ], [ "Tachibana", "Motoi", "" ], [ "Yamamoto", "Naoki", "" ], [ "Baym", "Gordon", "" ] ]
We study the interplay between chiral and diquark condensates within the framework of the Ginzburg-Landau free energy, and classify possible phase structures of two and three-flavor massless QCD. The QCD axial anomaly acts as an external field applied to the chiral condensate in a color superconductor and leads to a crossover between the broken chiral symmetry and the color superconducting phase, and, in particular, to a new critical point in the QCD phase diagram.
hep-ph/0210165
Maxim V. Polyakov
M.V. Polyakov
Generalized parton distributions and strong forces inside nucleons and nuclei
null
Phys.Lett. B555 (2003) 57-62
10.1016/S0370-2693(03)00036-4
RUB-TP2-14/02
hep-ph hep-ex nucl-th
null
We argue that generalized parton distributions (GPDs), accessible in hard exclusive processes, carry information about the spatial distribution of forces experienced by quarks and gluons inside hadrons. This way the measurements of hard exclusive processes open a possibility for direct "measurements" of strong forces in different parts of nucleons and nuclei. Also such studies open a venue for addressing questions of the properties of the quark (gluon) matter inside hadrons and nuclei. We give a simple example of relations between GPDs and properties of "nuclear matter" in finite nuclei.
[ { "created": "Thu, 10 Oct 2002 18:40:50 GMT", "version": "v1" } ]
2009-11-07
[ [ "Polyakov", "M. V.", "" ] ]
We argue that generalized parton distributions (GPDs), accessible in hard exclusive processes, carry information about the spatial distribution of forces experienced by quarks and gluons inside hadrons. This way the measurements of hard exclusive processes open a possibility for direct "measurements" of strong forces in different parts of nucleons and nuclei. Also such studies open a venue for addressing questions of the properties of the quark (gluon) matter inside hadrons and nuclei. We give a simple example of relations between GPDs and properties of "nuclear matter" in finite nuclei.
hep-ph/0501083
Stephen Godfrey
Stephen Godfrey (Carleton U)
Production of the h_c and h_b and Implications for Quarkonium Spectroscopy
Talk presented at the 1st Meeting of the APS Topical Group on Hadronic Physics (Fermilab, Oct 24-26, 2004), 4 pages, 1 figure, uses jpconf. References added
J.Phys.Conf.Ser. 9 (2005) 123-126
10.1088/1742-6596/9/1/023
null
hep-ph
null
The recent observation of the h_c is an important test of QCD calculations and provides constraints on models of quarkonium spectroscopy. In this contribution I discuss some of these implications and describe methods to search for the h_c and h_b via radiative transitions and other means.
[ { "created": "Tue, 11 Jan 2005 04:10:54 GMT", "version": "v1" }, { "created": "Mon, 17 Jan 2005 15:29:31 GMT", "version": "v2" } ]
2009-11-11
[ [ "Godfrey", "Stephen", "", "Carleton U" ] ]
The recent observation of the h_c is an important test of QCD calculations and provides constraints on models of quarkonium spectroscopy. In this contribution I discuss some of these implications and describe methods to search for the h_c and h_b via radiative transitions and other means.
hep-ph/9609253
V. A. Kuzmin
Vadim A. Kuzmin
Might Fast B-Violating Transitions Be Found Soon?
LaTeX file
null
null
Preprint INR-0931/Aug 1996
hep-ph
null
We claim that there might exist a new interaction leading to very fast baryon-number violating processes quite observable in the laboratory conditions, provided all three generations are simultaneously involved.
[ { "created": "Thu, 5 Sep 1996 07:26:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kuzmin", "Vadim A.", "" ] ]
We claim that there might exist a new interaction leading to very fast baryon-number violating processes quite observable in the laboratory conditions, provided all three generations are simultaneously involved.
hep-ph/0611107
Satoshi Mishima
Wei-Shu Hou, Hsiang-nan Li, Satoshi Mishima, Makiko Nagashima
Fourth Generation CP Violation Effect on B -> K pi, phi K and rho K in NLO PQCD
4 pages, 6 figures; version to appear in Phys. Rev. Lett
Phys.Rev.Lett.98:131801,2007
10.1103/PhysRevLett.98.131801
null
hep-ph
null
We study the effect from a sequential fourth generation quark on penguin-dominated two-body nonleptonic B meson decays in the next-to-leading order perturbative QCD formalism. With an enhancement of the color-suppressed tree amplitude and possibility of a new CP phase in the electroweak penguin, we can account better for A_{CP}(B^0 -> K^+ pi^-)-A_{CP}(B^+ -> K^+ pi^0). Taking |V_{t's}V_{t'b}| \sim 0.02 with phase just below 90^\circ, which are consistent with the b -> s l^+ l^- rate and the B_s mixing parameter \Delta m_{B_s}, we find a downward shift in the mixing-induced CP asymmetries of B^0 -> K_S pi^0 and phi K_S. The predicted behavior for B^0 -> rho^0 K_S is opposite.
[ { "created": "Wed, 8 Nov 2006 19:21:29 GMT", "version": "v1" }, { "created": "Thu, 29 Mar 2007 19:00:59 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hou", "Wei-Shu", "" ], [ "Li", "Hsiang-nan", "" ], [ "Mishima", "Satoshi", "" ], [ "Nagashima", "Makiko", "" ] ]
We study the effect from a sequential fourth generation quark on penguin-dominated two-body nonleptonic B meson decays in the next-to-leading order perturbative QCD formalism. With an enhancement of the color-suppressed tree amplitude and possibility of a new CP phase in the electroweak penguin, we can account better for A_{CP}(B^0 -> K^+ pi^-)-A_{CP}(B^+ -> K^+ pi^0). Taking |V_{t's}V_{t'b}| \sim 0.02 with phase just below 90^\circ, which are consistent with the b -> s l^+ l^- rate and the B_s mixing parameter \Delta m_{B_s}, we find a downward shift in the mixing-induced CP asymmetries of B^0 -> K_S pi^0 and phi K_S. The predicted behavior for B^0 -> rho^0 K_S is opposite.
1202.5088
Qiang Zhao
Qian Wang, Gang Li, and Qiang Zhao
Probing scalar meson structures in $\chi_{c1}$ decays into pseudoscalar and scalar
9 pages and 6 eps figures; Enhanced discussion on the dominance of hair-pin diagram is added. Revised version to appear in IJMPA
null
10.1142/S0217751X12501357
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the decay branching ratios of $\chi_{c1}\to PS$, in a quark model parametrization scheme, where $P$ and $S$ stand for pseudoscalar and scalar meson, respectively. An interesting feature of this decay process is that the $c\bar{c}$ annihilate via the pQCD hair-pin diagram is supposed to be dominant. Hence, this decay process should be sensitive to the quark components of the final-state light mesons, and would provide a great opportunity for testing the mixing relations among the scalar mesons, i.e. $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$, by tagging the final state pseudoscalar mesons.
[ { "created": "Thu, 23 Feb 2012 04:57:55 GMT", "version": "v1" }, { "created": "Tue, 31 Jul 2012 04:23:34 GMT", "version": "v2" } ]
2015-06-04
[ [ "Wang", "Qian", "" ], [ "Li", "Gang", "" ], [ "Zhao", "Qiang", "" ] ]
We evaluate the decay branching ratios of $\chi_{c1}\to PS$, in a quark model parametrization scheme, where $P$ and $S$ stand for pseudoscalar and scalar meson, respectively. An interesting feature of this decay process is that the $c\bar{c}$ annihilate via the pQCD hair-pin diagram is supposed to be dominant. Hence, this decay process should be sensitive to the quark components of the final-state light mesons, and would provide a great opportunity for testing the mixing relations among the scalar mesons, i.e. $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$, by tagging the final state pseudoscalar mesons.
1912.08204
Timon Emken
Riccardo Catena, Timon Emken, Nicola A. Spaldin, Walter Tarantino
Atomic responses to general dark matter-electron interactions
30 pages, 10 figures. Code available at https://github.com/temken/DarkARC and https://doi.org/10.5281/zenodo.3581334 . v2: matches published version
Phys. Rev. Research 2, 033195 (2020)
10.1103/PhysRevResearch.2.033195
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the leading paradigm of modern cosmology, about 80% of our Universe's matter content is in the form of hypothetical, as yet undetected particles. These do not emit or absorb radiation at any observable wavelengths, and therefore constitute the so-called Dark Matter (DM) component of the Universe. Detecting the particles forming the Milky Way DM component is one of the main challenges for astroparticle physics and basic science in general. One promising way to achieve this goal is to search for rare DM-electron interactions in low-background deep underground detectors. Key to the interpretation of this search is the response of detectors' materials to elementary DM-electron interactions defined in terms of electron wave functions' overlap integrals. In this work, we compute the response of atomic argon and xenon targets used in operating DM search experiments to general, so far unexplored DM-electron interactions. We find that the rate at which atoms can be ionized via DM-electron scattering can in general be expressed in terms of four independent atomic responses, three of which we identify here for the first time. We find our new atomic responses to be numerically important in a variety of cases, which we identify and investigate thoroughly using effective theory methods. We then use our atomic responses to set 90% confidence level (C.L.) exclusion limits on the strength of a wide range of DM-electron interactions from the null result of DM search experiments using argon and xenon targets.
[ { "created": "Tue, 17 Dec 2019 19:00:00 GMT", "version": "v1" }, { "created": "Wed, 19 Aug 2020 09:06:25 GMT", "version": "v2" } ]
2020-08-20
[ [ "Catena", "Riccardo", "" ], [ "Emken", "Timon", "" ], [ "Spaldin", "Nicola A.", "" ], [ "Tarantino", "Walter", "" ] ]
In the leading paradigm of modern cosmology, about 80% of our Universe's matter content is in the form of hypothetical, as yet undetected particles. These do not emit or absorb radiation at any observable wavelengths, and therefore constitute the so-called Dark Matter (DM) component of the Universe. Detecting the particles forming the Milky Way DM component is one of the main challenges for astroparticle physics and basic science in general. One promising way to achieve this goal is to search for rare DM-electron interactions in low-background deep underground detectors. Key to the interpretation of this search is the response of detectors' materials to elementary DM-electron interactions defined in terms of electron wave functions' overlap integrals. In this work, we compute the response of atomic argon and xenon targets used in operating DM search experiments to general, so far unexplored DM-electron interactions. We find that the rate at which atoms can be ionized via DM-electron scattering can in general be expressed in terms of four independent atomic responses, three of which we identify here for the first time. We find our new atomic responses to be numerically important in a variety of cases, which we identify and investigate thoroughly using effective theory methods. We then use our atomic responses to set 90% confidence level (C.L.) exclusion limits on the strength of a wide range of DM-electron interactions from the null result of DM search experiments using argon and xenon targets.
1404.0113
Anson Hook
Anson Hook
Baryogenesis from Hawking Radiation
12 pages, 3 figures. Journal version
Phys. Rev. D 90, 083535 (2014)
10.1103/PhysRevD.90.083535
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that in the presence of a chemical potential, black hole evaporation generates baryon number. If the inflaton or Ricci scalar is derivatively coupled to the B-L current, the expansion of the universe acts as a chemical potential and splits the energy levels of particles and their anti-particles. The asymmetric Hawking radiation of primordial black holes can thus be used to generate a B-L asymmetry. If dark matter is produced by the same mechanism, the coincidence between the mass density of visible and dark matter can be naturally explained.
[ { "created": "Tue, 1 Apr 2014 02:54:42 GMT", "version": "v1" }, { "created": "Mon, 12 May 2014 20:13:06 GMT", "version": "v2" }, { "created": "Mon, 5 Jan 2015 19:01:37 GMT", "version": "v3" } ]
2015-01-06
[ [ "Hook", "Anson", "" ] ]
We show that in the presence of a chemical potential, black hole evaporation generates baryon number. If the inflaton or Ricci scalar is derivatively coupled to the B-L current, the expansion of the universe acts as a chemical potential and splits the energy levels of particles and their anti-particles. The asymmetric Hawking radiation of primordial black holes can thus be used to generate a B-L asymmetry. If dark matter is produced by the same mechanism, the coincidence between the mass density of visible and dark matter can be naturally explained.
hep-ph/9806496
Falcone
D. Falcone and F. Tramontano
Relation between quark masses and weak mixings
8 pages LaTeX, no figures. Some misprints corrected and reference style changed
Phys.Rev.D59:017302,1999
10.1103/PhysRevD.59.017302
DSF-T-98/21
hep-ph
null
Simple transformation formulas between fermion matrices and observables, and numerical values of quark matrices, are obtained on a particular weak basis with one quark matrix diagonal and the other with vanishing elements 1-1, 1-3 and 3-1, and with only the element 2-2 complex. When we choose $M_u$ diagonal, then $M_d$ shows intriguing numerical properties which suggest a four parameter description of it, which implies $V_{us}\simeq \sqrt{m_d/m_s}$, $V_{cb}\simeq (3/\sqrt{5})(m_s/m_b)$ and $V_{ub}\simeq (1/\sqrt{5})(\sqrt{m_d m_s}/m_b)$. Few comments on mass-mixing relations are added.
[ { "created": "Fri, 26 Jun 1998 11:32:33 GMT", "version": "v1" }, { "created": "Thu, 2 Jul 1998 08:22:02 GMT", "version": "v2" } ]
2011-02-01
[ [ "Falcone", "D.", "" ], [ "Tramontano", "F.", "" ] ]
Simple transformation formulas between fermion matrices and observables, and numerical values of quark matrices, are obtained on a particular weak basis with one quark matrix diagonal and the other with vanishing elements 1-1, 1-3 and 3-1, and with only the element 2-2 complex. When we choose $M_u$ diagonal, then $M_d$ shows intriguing numerical properties which suggest a four parameter description of it, which implies $V_{us}\simeq \sqrt{m_d/m_s}$, $V_{cb}\simeq (3/\sqrt{5})(m_s/m_b)$ and $V_{ub}\simeq (1/\sqrt{5})(\sqrt{m_d m_s}/m_b)$. Few comments on mass-mixing relations are added.
hep-ph/0211070
G. Lugones
G. Lugones and J. E. Horvath
Color-flavor locked strange matter
5 pages, 2 figures
Phys.Rev. D66 (2002) 074017
10.1103/PhysRevD.66.074017
null
hep-ph
null
We analyze how the CFL states in dense matter work in the direction of enhancing the parameter space for absolutely stable phases (strange matter). We find that the "CFL strange matter" phase can be the true ground state of hadronic matter for a much wider range of the parameters of the model (the gap of the QCD Cooper pairs $\Delta$, the strange quark mass $m_s$ and the Bag Constant $B$) than the state without any pairing, and derive a full equation of state and an accurate analytic approximation to the lowest order in $\Delta$ and $m_{s}$ which may be directly used for applications. The effects of pairing on the equation of state are found to be small (as previously expected) but not negligible and may be relevant for astrophysics.
[ { "created": "Tue, 5 Nov 2002 22:48:40 GMT", "version": "v1" } ]
2009-11-07
[ [ "Lugones", "G.", "" ], [ "Horvath", "J. E.", "" ] ]
We analyze how the CFL states in dense matter work in the direction of enhancing the parameter space for absolutely stable phases (strange matter). We find that the "CFL strange matter" phase can be the true ground state of hadronic matter for a much wider range of the parameters of the model (the gap of the QCD Cooper pairs $\Delta$, the strange quark mass $m_s$ and the Bag Constant $B$) than the state without any pairing, and derive a full equation of state and an accurate analytic approximation to the lowest order in $\Delta$ and $m_{s}$ which may be directly used for applications. The effects of pairing on the equation of state are found to be small (as previously expected) but not negligible and may be relevant for astrophysics.
1202.2361
Jonathan Walsh
Randall Kelley, Jonathan R. Walsh, Saba Zuberi
Abelian Non-Global Logarithms from Soft Gluon Clustering
22 pages + appendices, 8 figures
null
10.1007/JHEP09(2012)117
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most recombination-style jet algorithms cluster soft gluons in a complex way. This leads to correlations in the soft gluon phase space and introduces logarithmic corrections to jet cross sections. The leading Abelian clustering logarithms occur at least at next-to leading logarithm (NLL) in the exponent of the distribution, and we show that new clustering effects contributing at NLL likely arise at each order. Therefore we find that it is unlikely that clustering logs can be resummed to NLL. Clustering logarithms make the anti-kT algorithm theoretically preferred, for which they are power suppressed. They can arise in Abelian and non-Abelian terms, and we calculate the Abelian clustering logarithms at two loops for the jet mass distribution using the Cambridge/Aachen and kT algorithms, including jet radius dependence, which extends previous results. We find that previously identified logarithms from clustering effects can be naturally thought of as a class of non-global logarithms (NGLs), which have traditionally been tied to non-Abelian correlations in soft gluon emission.
[ { "created": "Fri, 10 Feb 2012 21:00:04 GMT", "version": "v1" } ]
2015-06-04
[ [ "Kelley", "Randall", "" ], [ "Walsh", "Jonathan R.", "" ], [ "Zuberi", "Saba", "" ] ]
Most recombination-style jet algorithms cluster soft gluons in a complex way. This leads to correlations in the soft gluon phase space and introduces logarithmic corrections to jet cross sections. The leading Abelian clustering logarithms occur at least at next-to leading logarithm (NLL) in the exponent of the distribution, and we show that new clustering effects contributing at NLL likely arise at each order. Therefore we find that it is unlikely that clustering logs can be resummed to NLL. Clustering logarithms make the anti-kT algorithm theoretically preferred, for which they are power suppressed. They can arise in Abelian and non-Abelian terms, and we calculate the Abelian clustering logarithms at two loops for the jet mass distribution using the Cambridge/Aachen and kT algorithms, including jet radius dependence, which extends previous results. We find that previously identified logarithms from clustering effects can be naturally thought of as a class of non-global logarithms (NGLs), which have traditionally been tied to non-Abelian correlations in soft gluon emission.
1106.1423
Zvi Bern
Z. Bern, G. Diana, L. J. Dixon, F. Febres Cordero, S. Hoeche, H. Ita, D. A. Kosower, D. Maitre and K. J. Ozeren
Driving Missing Data at Next-to-Leading Order
27 pages, 9 figures, 3 tables, RevTex, v2 minor corrections and added references
Phys.Rev.D84:114002,2011
10.1103/PhysRevD.84.114002
SLAC--PUB--14472, UCLA/11/TEP/106, CERN--PH--TH/2011-125, IPhT--T11/146, IPPP/11/29, NSF--KITP--11--093, SB/F/387-11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The prediction of backgrounds to new physics signals in topologies with large missing transverse energy and jets is important to new physics searches at the LHC. Following a CMS study, we investigate theoretical issues in using measurements of gamma + 2-jet production to predict the irreducible background to searches for missing energy plus two jets that originates from Z + 2-jet production where the Z boson decays to neutrinos. We compute ratios of gamma + 2-jet to Z + 2-jet production cross sections and kinematic distributions at next-to-leading order in alpha_s, as well as using a parton shower matched to leading-order matrix elements. We find that the ratios obtained in the two approximations are quite similar, making gamma + 2-jet production a theoretically reliable estimator for the missing energy plus two jets background. We employ a Frixione-style photon isolation, but we also show that for isolated prompt photon production at high transverse momentum the difference between this criterion and the standard cone isolation used by CMS is small.
[ { "created": "Tue, 7 Jun 2011 19:46:50 GMT", "version": "v1" }, { "created": "Wed, 13 Jul 2011 06:40:20 GMT", "version": "v2" } ]
2015-03-19
[ [ "Bern", "Z.", "" ], [ "Diana", "G.", "" ], [ "Dixon", "L. J.", "" ], [ "Cordero", "F. Febres", "" ], [ "Hoeche", "S.", "" ], [ "Ita", "H.", "" ], [ "Kosower", "D. A.", "" ], [ "Maitre", "D.", "" ], [ "Ozeren", "K. J.", "" ] ]
The prediction of backgrounds to new physics signals in topologies with large missing transverse energy and jets is important to new physics searches at the LHC. Following a CMS study, we investigate theoretical issues in using measurements of gamma + 2-jet production to predict the irreducible background to searches for missing energy plus two jets that originates from Z + 2-jet production where the Z boson decays to neutrinos. We compute ratios of gamma + 2-jet to Z + 2-jet production cross sections and kinematic distributions at next-to-leading order in alpha_s, as well as using a parton shower matched to leading-order matrix elements. We find that the ratios obtained in the two approximations are quite similar, making gamma + 2-jet production a theoretically reliable estimator for the missing energy plus two jets background. We employ a Frixione-style photon isolation, but we also show that for isolated prompt photon production at high transverse momentum the difference between this criterion and the standard cone isolation used by CMS is small.
hep-ph/9706473
Amir Fariborz
T. G. Steele, J. C. Breckenridge, M. Benmerrouche, V. Elias and A. H. Fariborz
QCD Laplace Sum Rules and the $\Pi (1300)$ Resonance
3 pages, latex, no figures, uses sprocl.sty, to appear in the proceedings of the DPF 1996 meeting, Minneapolis
null
null
null
hep-ph
null
A global fit to the shape of the first QCD Laplace sum rule exhibiting sensitivity to pion-resonance [$\Pi (1300)$] parameters is performed, leading to predictions for the pion-resonance mass and decay constant. This fit leads to predictions of $M_{\pi} = 1.15 \pm 0.15 GeV$ for the pion-resonance mass, and $F_\pi^2=(4.5\pm 2.1).(f_\pi^2m_\pi^4/M_\pi^4)$ for the pion-resonance decay constant.
[ { "created": "Mon, 23 Jun 1997 21:56:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Steele", "T. G.", "" ], [ "Breckenridge", "J. C.", "" ], [ "Benmerrouche", "M.", "" ], [ "Elias", "V.", "" ], [ "Fariborz", "A. H.", "" ] ]
A global fit to the shape of the first QCD Laplace sum rule exhibiting sensitivity to pion-resonance [$\Pi (1300)$] parameters is performed, leading to predictions for the pion-resonance mass and decay constant. This fit leads to predictions of $M_{\pi} = 1.15 \pm 0.15 GeV$ for the pion-resonance mass, and $F_\pi^2=(4.5\pm 2.1).(f_\pi^2m_\pi^4/M_\pi^4)$ for the pion-resonance decay constant.
1503.08849
Theodore Brennan
T. Daniel Brennan
Two Loop Unification of Non-SUSY SO(10) GUT with TeV Scalars
null
Phys. Rev. D 95, 065008 (2017)
10.1103/PhysRevD.95.065008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we examine gauge coupling unification of the the non-SUSY SO(10) grand unified theory proposed by Babu and Mohapatra at the two loop level. This theory breaks down to the standard model in a single step and has the distinguishing feature of TeV non-standard model scalars. This leads to a plethora of interesting new physics at the TeV scale and the discovery of new particles at the LHC. This model gives rise to testable proton decay, neutron-antineutron oscillations, provides a mechanism for baryogenesis, and contains potential dark matter candidates. In this paper, we compute the two loop beta function and show that this model unifies to two loop order around $10^{15}$ GeV. We then compute the proton lifetime, taking into account threshold effects and show that these effects place it above the Super Kamiokande limit.
[ { "created": "Mon, 30 Mar 2015 20:44:42 GMT", "version": "v1" }, { "created": "Wed, 12 Oct 2016 22:38:34 GMT", "version": "v2" }, { "created": "Wed, 22 Feb 2017 15:32:32 GMT", "version": "v3" } ]
2017-03-15
[ [ "Brennan", "T. Daniel", "" ] ]
In this paper we examine gauge coupling unification of the the non-SUSY SO(10) grand unified theory proposed by Babu and Mohapatra at the two loop level. This theory breaks down to the standard model in a single step and has the distinguishing feature of TeV non-standard model scalars. This leads to a plethora of interesting new physics at the TeV scale and the discovery of new particles at the LHC. This model gives rise to testable proton decay, neutron-antineutron oscillations, provides a mechanism for baryogenesis, and contains potential dark matter candidates. In this paper, we compute the two loop beta function and show that this model unifies to two loop order around $10^{15}$ GeV. We then compute the proton lifetime, taking into account threshold effects and show that these effects place it above the Super Kamiokande limit.
1706.02017
Sushant Raut
Debasish Borah, Monojit Ghosh, Shivani Gupta, Sushant K. Raut
Texture zeros of low-energy Majorana neutrino mass matrix in 3+1 scheme
12 pages, 3 figures. Version published in PRD
Phys. Rev. D 96, 055017 (2017)
10.1103/PhysRevD.96.055017
ADP-17 - 24 / T1030, CTPU-17-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we revisit the zero textures in low energy Majorana neutrino mass matrix when the active neutrino sector is extended by a light sterile neutrino in the eV scale i.e., the 3+1 scheme. In 3+1 scenario, the low energy neutrino mass matrix ($m_\nu$) has ten independent elements. Thus in principle one can have minimum one-zero texture to maximum ten-zero texture. We summarize the previous results of one, two, three and four-zero textures which already exist in the literature and present our new results on five-zero textures. In our analysis we find that among six possible five-zero textures, only one is allowed by the present data. We discuss possible theoretical model which can explain the origin of the allowed five-zero texture and discuss other possible implications of such a scenario. Our results also concludes that in 3+1 scheme, one can not have more than five-zeros in $m_\nu$.
[ { "created": "Wed, 7 Jun 2017 01:33:41 GMT", "version": "v1" }, { "created": "Tue, 26 Sep 2017 07:42:03 GMT", "version": "v2" } ]
2017-09-27
[ [ "Borah", "Debasish", "" ], [ "Ghosh", "Monojit", "" ], [ "Gupta", "Shivani", "" ], [ "Raut", "Sushant K.", "" ] ]
In this work we revisit the zero textures in low energy Majorana neutrino mass matrix when the active neutrino sector is extended by a light sterile neutrino in the eV scale i.e., the 3+1 scheme. In 3+1 scenario, the low energy neutrino mass matrix ($m_\nu$) has ten independent elements. Thus in principle one can have minimum one-zero texture to maximum ten-zero texture. We summarize the previous results of one, two, three and four-zero textures which already exist in the literature and present our new results on five-zero textures. In our analysis we find that among six possible five-zero textures, only one is allowed by the present data. We discuss possible theoretical model which can explain the origin of the allowed five-zero texture and discuss other possible implications of such a scenario. Our results also concludes that in 3+1 scheme, one can not have more than five-zeros in $m_\nu$.
1112.4515
S. V. Troitsky
Sergey Troitsky
Unsolved problems in particle physics
49 pages, 20 figures. A review lecture for physics students and general physicists, to be published in Physics Uspekhi in January 2012
Physics Uspekhi 55 (2012) 72-95 (Uspekhi Fiz. Nauk 182 (2012) 77-103)
10.3367/UFNe.0182.201201d.0077
INR-1306/2011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I consider selected (most important according to my own choice) unsolved problems in particle theory, both those related to extensions of the Standard Model (neutrino oscillations, which probably do not fit the usual three-generation scheme; indications in favour of new physics from astrophysical observations; electroweak symmetry breaking and hierarchy of parameters) and those which appear in the Standard Model (description of strong interactions at low and intermediate energies).
[ { "created": "Mon, 19 Dec 2011 22:18:35 GMT", "version": "v1" } ]
2015-06-03
[ [ "Troitsky", "Sergey", "" ] ]
I consider selected (most important according to my own choice) unsolved problems in particle theory, both those related to extensions of the Standard Model (neutrino oscillations, which probably do not fit the usual three-generation scheme; indications in favour of new physics from astrophysical observations; electroweak symmetry breaking and hierarchy of parameters) and those which appear in the Standard Model (description of strong interactions at low and intermediate energies).
hep-ph/0012003
Chao-Qiang Geng
Chuan-Hung Chen and C.Q. Geng
Study of $\Lambda_b\to\Lambda\nu\bar{\nu}$ with Polarized Baryons
19 pages, 8 Figures, LaTex file, to be published in PRD
Phys.Rev. D63 (2001) 054005
10.1103/PhysRevD.63.054005
null
hep-ph
null
We investigate the decay of $\Lambda_b\to\Lambda\nu\bar{\nu}$ with the polarized baryons of $\Lambda_b$ and $\Lambda$. With the most general hadronic form factors, we first study the decay branching ratio and then derive the longitudinal, normal and transverse polarizations of $\Lambda$ in terms of the spin unit vectors of $\Lambda_b$ and $\Lambda $ and the momentum of $\Lambda $. A polarization of $\Lambda_b$ is also discussed.
[ { "created": "Fri, 1 Dec 2000 07:42:24 GMT", "version": "v1" } ]
2009-10-31
[ [ "Chen", "Chuan-Hung", "" ], [ "Geng", "C. Q.", "" ] ]
We investigate the decay of $\Lambda_b\to\Lambda\nu\bar{\nu}$ with the polarized baryons of $\Lambda_b$ and $\Lambda$. With the most general hadronic form factors, we first study the decay branching ratio and then derive the longitudinal, normal and transverse polarizations of $\Lambda$ in terms of the spin unit vectors of $\Lambda_b$ and $\Lambda $ and the momentum of $\Lambda $. A polarization of $\Lambda_b$ is also discussed.
1204.6642
Marek Karliner
John Ellis and Marek Karliner
Indications on the Mass of the Lightest Electroweak Baryon
References added
null
10.1016/j.physletb.2012.05.056
KCL-PH-TH/2012-18; LCTS/2012-10; CERN-PH-TH/2012-103; TAUP-2949/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In general, an effective low-energy Lagrangian model of composite electroweak symmetry breaking contains soliton solutions that may be identified with technibaryons. We recall how the masses of such states may be related to the coefficients of fourth-order terms in the effective Lagrangian, and review the qualitative success of this approach for baryons in QCD. We then show how the current theoretical and phenomenological constraints on the corresponding fourth-order coefficients in the electroweak theory could be used to estimate qualitative lower and upper bounds on the lightest electroweak baryon mass. We also discuss how the sensitivity of the LHC experiments could enable these bounds to be improved.
[ { "created": "Mon, 30 Apr 2012 14:10:59 GMT", "version": "v1" }, { "created": "Tue, 15 May 2012 18:10:36 GMT", "version": "v2" } ]
2015-06-04
[ [ "Ellis", "John", "" ], [ "Karliner", "Marek", "" ] ]
In general, an effective low-energy Lagrangian model of composite electroweak symmetry breaking contains soliton solutions that may be identified with technibaryons. We recall how the masses of such states may be related to the coefficients of fourth-order terms in the effective Lagrangian, and review the qualitative success of this approach for baryons in QCD. We then show how the current theoretical and phenomenological constraints on the corresponding fourth-order coefficients in the electroweak theory could be used to estimate qualitative lower and upper bounds on the lightest electroweak baryon mass. We also discuss how the sensitivity of the LHC experiments could enable these bounds to be improved.
hep-ph/0006123
null
H. Athar, G. Parente, E. Zas
Prospects for observations of high-energy cosmic tau neutrinos
10 pages, Revtex, 3 figures included with epsf
Phys.Rev.D62:093010,2000
10.1103/PhysRevD.62.093010
TMUP-HEL-0012
hep-ph astro-ph hep-ex
null
We study prospects for the observations of high-energy cosmic tau neutrinos (E \geq 10^6 GeV) originating from proton acceleration in the cores of active galactic nuclei. We consider the possibility that vacuum flavor neutrino oscillations induce a tau to muon neutrino flux ratio greatly exceeding the rather small value expected from intrinsic production. The criterias and event rates for under water/ice light Cerenkov neutrino telescopes are given by considering the possible detection of downgoing high-energy cosmic tau neutrinos through characteristic double shower events.
[ { "created": "Tue, 13 Jun 2000 05:28:22 GMT", "version": "v1" } ]
2010-12-03
[ [ "Athar", "H.", "" ], [ "Parente", "G.", "" ], [ "Zas", "E.", "" ] ]
We study prospects for the observations of high-energy cosmic tau neutrinos (E \geq 10^6 GeV) originating from proton acceleration in the cores of active galactic nuclei. We consider the possibility that vacuum flavor neutrino oscillations induce a tau to muon neutrino flux ratio greatly exceeding the rather small value expected from intrinsic production. The criterias and event rates for under water/ice light Cerenkov neutrino telescopes are given by considering the possible detection of downgoing high-energy cosmic tau neutrinos through characteristic double shower events.
0710.2234
K. Sridhar
M. Guchait, F. Mahmoudi and K. Sridhar
Associated production of a Kaluza-Klein excitation of a gluon with a t t(bar) pair at the LHC
11 pages, 3 figures
Phys.Lett.B666:347-351,2008
10.1016/j.physletb.2008.07.085
TIFR/TH/07-24
hep-ph
null
In Randall-Sundrum models, the Kaluza-Klein (KK) excitations of the gluon, g_{KK} have enhanced couplings to the right-handed quarks. In the absence of a gg g_{KK} coupling in these models, the single production of a g_{KK} from an initial gg state is not possible. The search for other production mechanisms at the LHC, therefore, becomes important. We suggest that the associated production of a g_{KK} with a t t(bar) pair is such a mechanism. Our study shows that through this process the LHC can probe KK gluon masses in the range of 2.8 -- 2.9 TeV.
[ { "created": "Thu, 11 Oct 2007 12:40:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Guchait", "M.", "" ], [ "Mahmoudi", "F.", "" ], [ "Sridhar", "K.", "" ] ]
In Randall-Sundrum models, the Kaluza-Klein (KK) excitations of the gluon, g_{KK} have enhanced couplings to the right-handed quarks. In the absence of a gg g_{KK} coupling in these models, the single production of a g_{KK} from an initial gg state is not possible. The search for other production mechanisms at the LHC, therefore, becomes important. We suggest that the associated production of a g_{KK} with a t t(bar) pair is such a mechanism. Our study shows that through this process the LHC can probe KK gluon masses in the range of 2.8 -- 2.9 TeV.
hep-ph/0610102
Lev Fil'kov
L.V. Fil'kov and V.L. Kashevarov
Pion Polarizabilities
10 pages, 5 figures. Talk given at XI International Seminar on Electromagnetic Interactions of Nuclei (EMIN-2006), September 21-24, 2006, Moscow, Russia. Typos corrected
null
null
null
hep-ph hep-ex nucl-ex nucl-th
null
Recent experimental pion polarizability data are reviewed and analyzed. Data on the radiative \pi^+ meson photoproduction on the proton at MAMI has been used to determine the difference of the electric and magnetic dipole polarizabilities of the charged pion. Fits of the experimental data to the total cross sections of the processes \gamma\gamma->\pi^0\pi^0 and \gamma\gamma->\pi^\pm\pi^\pm in the energy region from threshold to 2250 MeV and 2500 MeV, respectively, have been carried out using dispersion relations with subtractions for the invariant helicity amplitudes, where the dipole and the quadrupole polarizabilities of \pi^0 and \pi^\pm are free parameters. These fits have allowed ones to find the sum and the difference of the electric and magnetic dipole and quadrupole polarizabilities of the pions. These data are compared with the dispersion sum rules and ChPT calculations. The value of the difference of the charged pion dipole polarizabilities found from the fit is in a good agreement with the results obtained at MAMI (2005), in Serpukhov (1983) and Lebedev Physical Institute (1984). However, all these values deviate from the recent calculations in the framework of ChPT.
[ { "created": "Mon, 9 Oct 2006 15:37:39 GMT", "version": "v1" }, { "created": "Mon, 13 Nov 2006 14:59:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Fil'kov", "L. V.", "" ], [ "Kashevarov", "V. L.", "" ] ]
Recent experimental pion polarizability data are reviewed and analyzed. Data on the radiative \pi^+ meson photoproduction on the proton at MAMI has been used to determine the difference of the electric and magnetic dipole polarizabilities of the charged pion. Fits of the experimental data to the total cross sections of the processes \gamma\gamma->\pi^0\pi^0 and \gamma\gamma->\pi^\pm\pi^\pm in the energy region from threshold to 2250 MeV and 2500 MeV, respectively, have been carried out using dispersion relations with subtractions for the invariant helicity amplitudes, where the dipole and the quadrupole polarizabilities of \pi^0 and \pi^\pm are free parameters. These fits have allowed ones to find the sum and the difference of the electric and magnetic dipole and quadrupole polarizabilities of the pions. These data are compared with the dispersion sum rules and ChPT calculations. The value of the difference of the charged pion dipole polarizabilities found from the fit is in a good agreement with the results obtained at MAMI (2005), in Serpukhov (1983) and Lebedev Physical Institute (1984). However, all these values deviate from the recent calculations in the framework of ChPT.
2001.11347
Dave Dunbar
David C. Dunbar, Warren B. Perkins and Joseph M.W. Strong
An $n$-point QCD two-loop amplitude
v3 : clarification of eq 7.2, citations updated. arXiv admin note: text overlap with arXiv:1911.06547
Phys. Rev. D 101, 076001 (2020)
10.1103/PhysRevD.101.076001
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an explicit expression for a particular $n$-gluon two loop scattering partial amplitude. Specifically we present an analytic form for the single trace $N_c$ independent colour partial amplitude for the case where all external gluons have positive helicity.
[ { "created": "Thu, 30 Jan 2020 14:25:40 GMT", "version": "v1" }, { "created": "Thu, 13 Feb 2020 13:24:18 GMT", "version": "v2" }, { "created": "Thu, 12 Mar 2020 10:03:41 GMT", "version": "v3" } ]
2020-04-08
[ [ "Dunbar", "David C.", "" ], [ "Perkins", "Warren B.", "" ], [ "Strong", "Joseph M. W.", "" ] ]
We present an explicit expression for a particular $n$-gluon two loop scattering partial amplitude. Specifically we present an analytic form for the single trace $N_c$ independent colour partial amplitude for the case where all external gluons have positive helicity.
hep-ph/9607402
null
I.G.Aznauryan
Relativistic effects in radiative transitions of charmonia
9 pages, LaTeX file, no figs
Phys.Lett.B398:158-162,1997
10.1016/S0370-2693(97)00203-7
null
hep-ph
null
In the framework of a relativistic quark model constructed in an infinite momentum frame, corrections of the order of $v^{2}/c^{2}$ are obtained in the formulas which express amplitudes of the transitions $\psi(\psi') \to \eta_{_{c}}(\eta'_{_{c}})\gamma$, $\chi_{_{J}} \to \psi\gamma$, $\psi' \to \chi_{_{J}}\gamma$, $h_{_{c}} \to \eta_{_{c}}\gamma$, $\eta'_{_{c}} \to h_{_{c}}\gamma$ through overlap integrals $\int \phi^{*}_{f}(q) \phi_{i}(q) d{\bf q}$, $\int \phi^{*}_{f}(r)r \phi_{i}(r) d{\bf r}$. These corrections lead to a considerable suppression of $\Gamma(\psi\to\eta_{_{c}}\gamma)$, however, they are insufficient to remove the existing disagreement of quark model predictions with experiment. Taking into account the relativistic corrections, the ratios of overlap integrals for $\chi_{_{0}} \to \psi\gamma, \chi_{_{2}} \to \psi\gamma$ and $\psi' \to \chi_{_{0}}\gamma, \psi' \to \chi_{_{2}}\gamma$ transitions are extracted from experiment; the obtained results are compared with quark model predictions.
[ { "created": "Tue, 23 Jul 1996 16:34:23 GMT", "version": "v1" } ]
2011-07-19
[ [ "Aznauryan", "I. G.", "" ] ]
In the framework of a relativistic quark model constructed in an infinite momentum frame, corrections of the order of $v^{2}/c^{2}$ are obtained in the formulas which express amplitudes of the transitions $\psi(\psi') \to \eta_{_{c}}(\eta'_{_{c}})\gamma$, $\chi_{_{J}} \to \psi\gamma$, $\psi' \to \chi_{_{J}}\gamma$, $h_{_{c}} \to \eta_{_{c}}\gamma$, $\eta'_{_{c}} \to h_{_{c}}\gamma$ through overlap integrals $\int \phi^{*}_{f}(q) \phi_{i}(q) d{\bf q}$, $\int \phi^{*}_{f}(r)r \phi_{i}(r) d{\bf r}$. These corrections lead to a considerable suppression of $\Gamma(\psi\to\eta_{_{c}}\gamma)$, however, they are insufficient to remove the existing disagreement of quark model predictions with experiment. Taking into account the relativistic corrections, the ratios of overlap integrals for $\chi_{_{0}} \to \psi\gamma, \chi_{_{2}} \to \psi\gamma$ and $\psi' \to \chi_{_{0}}\gamma, \psi' \to \chi_{_{2}}\gamma$ transitions are extracted from experiment; the obtained results are compared with quark model predictions.
hep-ph/0210169
Stefan Dittmaier
A.Denner, S.Dittmaier, M.Roth and D.Wackeroth
Challenges in W-pair production
9 pages, latex, 5 postscript files, to appear in the proceedings of the "International Workshop on Linear Colliders", August 26-30, 2002, Jeju Island, Korea
null
null
KA-TP-17-2002, MPI-PhT/2002-57, PSI-PR-02-13, UB-HET-02-07
hep-ph
null
The investigation of W-pair production offers unique precision tests of the electroweak theory at future e+e- colliders, including precise determinations of cross sections, the W-boson mass, and gauge-boson self-couplings. The state-of-the-art and future requirements in the theoretical prediction for the reaction e+e- -> WW -> 4f(+gamma) are briefly reviewed.
[ { "created": "Thu, 10 Oct 2002 19:33:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Denner", "A.", "" ], [ "Dittmaier", "S.", "" ], [ "Roth", "M.", "" ], [ "Wackeroth", "D.", "" ] ]
The investigation of W-pair production offers unique precision tests of the electroweak theory at future e+e- colliders, including precise determinations of cross sections, the W-boson mass, and gauge-boson self-couplings. The state-of-the-art and future requirements in the theoretical prediction for the reaction e+e- -> WW -> 4f(+gamma) are briefly reviewed.
1203.0086
Bo-Qiang Ma
Bo-Qiang Ma
New Chance for Researches on Lorentz Violation
12 pages, no figure. Contribution to the Proceedings of the Symposium on Cosmology and Particle Astrophysics (CosPA2011), based on a talk at this symposium and also a number of talks and seminars elsewhere. Version for publication
Int.J.Mod.Phys.Conf.Ser.10 (2012) 195-206
10.1142/S2010194512005910
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present a brief review on the motivation for the study on Lorentz violation and on some of our studies with phenomenological analysis of Lorentz violation effects. I also discuss three effective field theory frameworks for Lorentz violation: the Coleman-Glashow model, the standard model extension (SME), and the standard model supplement (SMS). The situation of the OPERA "anomaly" is also briefly reviewed, together with some discussion on the superluminality of neutrinos within the effective field theory frameworks.
[ { "created": "Thu, 1 Mar 2012 04:19:11 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2012 17:13:51 GMT", "version": "v2" }, { "created": "Fri, 27 Apr 2012 04:45:14 GMT", "version": "v3" } ]
2012-05-21
[ [ "Ma", "Bo-Qiang", "" ] ]
I present a brief review on the motivation for the study on Lorentz violation and on some of our studies with phenomenological analysis of Lorentz violation effects. I also discuss three effective field theory frameworks for Lorentz violation: the Coleman-Glashow model, the standard model extension (SME), and the standard model supplement (SMS). The situation of the OPERA "anomaly" is also briefly reviewed, together with some discussion on the superluminality of neutrinos within the effective field theory frameworks.
2309.10365
Danny van Dyk
Anja Beck, M\'eril Reboud, Danny van Dyk
Testable Likelihoods for Beyond-the-Standard Model Fits
11 pages, 7 figures
null
null
IPPP/23/49
hep-ph cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Studying potential BSM effects at the precision frontier requires accurate transfer of information from low-energy measurements to high-energy BSM models. We propose to use normalising flows to construct likelihood functions that achieve this transfer. Likelihood functions constructed in this way provide the means to generate additional samples and admit a ``trivial'' goodness-of-fit test in form of a $\chi^2$ test statistic. Here, we study a particular form of normalising flow, apply it to a multi-modal and non-Gaussian example, and quantify the accuracy of the likelihood function and its test statistic.
[ { "created": "Tue, 19 Sep 2023 07:03:41 GMT", "version": "v1" } ]
2023-09-20
[ [ "Beck", "Anja", "" ], [ "Reboud", "Méril", "" ], [ "van Dyk", "Danny", "" ] ]
Studying potential BSM effects at the precision frontier requires accurate transfer of information from low-energy measurements to high-energy BSM models. We propose to use normalising flows to construct likelihood functions that achieve this transfer. Likelihood functions constructed in this way provide the means to generate additional samples and admit a ``trivial'' goodness-of-fit test in form of a $\chi^2$ test statistic. Here, we study a particular form of normalising flow, apply it to a multi-modal and non-Gaussian example, and quantify the accuracy of the likelihood function and its test statistic.
1805.00718
Fang Su
Qin Chang, Xiao-Nan Li, Xin-Qiang Li, and Fang Su
Decay constants of pseudoscalar and vector mesons with improved holographic wavefunction
27 pages, 4 figures and 3 tables; typos corrected, references added, final version published in Chinese Physics C
null
10.1088/1674-1137/42/7/073102
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the decay constants of light and heavy-light pseudoscalar and vector mesons with improved soft-wall holographic wavefuntions, which take into account the effects of both quark masses and dynamical spins. We find that the predicted decay constants, especially for the ratio $f_V/f_P$, based on light-front holographic QCD, can be significantly improved, once the dynamical spin effects are taken into account by introducing the helicity-dependent wavefunctions. We also perform detailed $\chi^2$ analyses for the holographic parameters ({\it i.e.} the mass-scale parameter $\kappa$ and the quark masses), by confronting our predictions with the data for the charged-meson decay constants and the meson spectra. The fitted values for these parameters are generally in agreement with those obtained by fitting to the Regge trajectories. At the same time, most of our results for the decay constants and their ratios agree with the data as well as the predictions based on lattice QCD and QCD sum rule approaches, with only a few exceptions observed.
[ { "created": "Wed, 2 May 2018 10:33:11 GMT", "version": "v1" }, { "created": "Mon, 14 May 2018 13:36:30 GMT", "version": "v2" } ]
2018-05-15
[ [ "Chang", "Qin", "" ], [ "Li", "Xiao-Nan", "" ], [ "Li", "Xin-Qiang", "" ], [ "Su", "Fang", "" ] ]
We calculate the decay constants of light and heavy-light pseudoscalar and vector mesons with improved soft-wall holographic wavefuntions, which take into account the effects of both quark masses and dynamical spins. We find that the predicted decay constants, especially for the ratio $f_V/f_P$, based on light-front holographic QCD, can be significantly improved, once the dynamical spin effects are taken into account by introducing the helicity-dependent wavefunctions. We also perform detailed $\chi^2$ analyses for the holographic parameters ({\it i.e.} the mass-scale parameter $\kappa$ and the quark masses), by confronting our predictions with the data for the charged-meson decay constants and the meson spectra. The fitted values for these parameters are generally in agreement with those obtained by fitting to the Regge trajectories. At the same time, most of our results for the decay constants and their ratios agree with the data as well as the predictions based on lattice QCD and QCD sum rule approaches, with only a few exceptions observed.
hep-ph/0210318
Anindya Datta
Anindya Datta, Emidio Gabrielli, Barbara Mele
Virtual graviton exchanges at the Z-pole in large extra dimensions
Version to appear in Physics Letters B
Phys.Lett. B552 (2003) 237-246
10.1016/S0370-2693(02)03164-7
HIP-2002-42/TH, ROME1-1345/2002
hep-ph hep-ex
null
In the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein gravitons on the imaginary part of the amplitude of the process e+ e- --> f f-bar are analyzed at the Z-pole. Notably, the interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Plank scale M_D. We find that, while the virtual-gravitons effect on total cross sections vanishes at tree-level, both angular and polarization asymmetries are modified by terms whose relative effect is at most of order 10^(-4) for M_D > 1 TeV. Possible shifts in the M_Z, due to changes in the Breit-Wigner line shape are also discussed.
[ { "created": "Wed, 23 Oct 2002 17:09:36 GMT", "version": "v1" }, { "created": "Thu, 7 Nov 2002 14:45:18 GMT", "version": "v2" }, { "created": "Sat, 7 Dec 2002 11:56:42 GMT", "version": "v3" } ]
2009-11-07
[ [ "Datta", "Anindya", "" ], [ "Gabrielli", "Emidio", "" ], [ "Mele", "Barbara", "" ] ]
In the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein gravitons on the imaginary part of the amplitude of the process e+ e- --> f f-bar are analyzed at the Z-pole. Notably, the interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Plank scale M_D. We find that, while the virtual-gravitons effect on total cross sections vanishes at tree-level, both angular and polarization asymmetries are modified by terms whose relative effect is at most of order 10^(-4) for M_D > 1 TeV. Possible shifts in the M_Z, due to changes in the Breit-Wigner line shape are also discussed.
1608.05588
Mustafa Savci
T. M. Aliev (1), T. Barakat (2), M. Savc{\i} (1) ((1) Middle East Technical University/Ankara/Turkey, (2) King Saud University/Riyadh/Saudi Arabia)
Strong coupling constant of negative parity nucleon with $\pi$ meson in light cone QCD sum rules
14 pages, 4 figures, LaTeX formatted
Phys. Rev. C 95, 035210 (2017)
10.1103/PhysRevC.95.035210
metu-phys-hep-16-17
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We estimate strong coupling constant between the negative parity nucleons with $\pi$ meson within the light cone QCD sum rules. A method for eliminating the unwanted contributions coming from the nucleon--nucleon and nucleon--negative parity nucleon transition is presented. It is observed that the value strong coupling constant of the negative parity nucleon $N^\ast N^\ast \pi$ transition is considerably different from the one predicted by the 3--point QCD sum rules, but is quite close to the coupling constant of the positive parity $N N \pi$ transition.
[ { "created": "Fri, 19 Aug 2016 12:53:45 GMT", "version": "v1" } ]
2017-04-05
[ [ "Aliev", "T. M.", "" ], [ "Barakat", "T.", "" ], [ "Savcı", "M.", "" ] ]
We estimate strong coupling constant between the negative parity nucleons with $\pi$ meson within the light cone QCD sum rules. A method for eliminating the unwanted contributions coming from the nucleon--nucleon and nucleon--negative parity nucleon transition is presented. It is observed that the value strong coupling constant of the negative parity nucleon $N^\ast N^\ast \pi$ transition is considerably different from the one predicted by the 3--point QCD sum rules, but is quite close to the coupling constant of the positive parity $N N \pi$ transition.
hep-ph/0307127
Hitoshi Murayama
Hitoshi Murayama (UC Berkeley, LBNL)
CPT Tests: Kaon vs Neutrinos
null
Phys.Lett.B597:73-77,2004
10.1016/j.physletb.2004.06.106
UCB-PTH-03/15, LBNL-53300
hep-ph
null
CPT violation has an impressive limit in the neutral kaon system |m(K^0) - m(\bar{K}^0)| < 10^{-18} m_K = 0.50 \times 10^{-18} GeV. However, if viewed as a constraint on the mass-squared, the bound appears weak, |m^2(K^0) - m^2(\bar{K}^0)| < 0.25 eV^2. We point out that neutrino oscillation offers better limits on CPT violation in this case. The comparison of solar and rector neutrino results puts the best limit on CPT violation by far, |\Delta m^2_\nu - \Delta m^2_{\bar{\nu}}| < 1.3 \times 10^{-3} eV^2 (90% CL).
[ { "created": "Wed, 9 Jul 2003 08:13:38 GMT", "version": "v1" } ]
2009-09-29
[ [ "Murayama", "Hitoshi", "", "UC Berkeley, LBNL" ] ]
CPT violation has an impressive limit in the neutral kaon system |m(K^0) - m(\bar{K}^0)| < 10^{-18} m_K = 0.50 \times 10^{-18} GeV. However, if viewed as a constraint on the mass-squared, the bound appears weak, |m^2(K^0) - m^2(\bar{K}^0)| < 0.25 eV^2. We point out that neutrino oscillation offers better limits on CPT violation in this case. The comparison of solar and rector neutrino results puts the best limit on CPT violation by far, |\Delta m^2_\nu - \Delta m^2_{\bar{\nu}}| < 1.3 \times 10^{-3} eV^2 (90% CL).
1311.3733
Walton A. Perkins
Walton A. Perkins
The Antiparticles of Neutral Bosons
15 pages, 1 figure
null
10.4236/jmp.2013.412A1003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the advent of the ability to create and study antihydrogen, we think it is appropriate to consider the possibility that antiphotons might not be identical to photons. First of all, we will look at the experimental evidence concerning multiple neutral pions and multiple photons. Because of its internal structure, the neutral kaon is not identical to its antiparticle. We will consider internal structures for the neutral pion and photon for which the antiparticle differs from the particle. Interestingly, the antiphoton thus created from neutrinos does not interact with electrons because its neutrinos have the wrong helicity.
[ { "created": "Fri, 15 Nov 2013 06:00:19 GMT", "version": "v1" } ]
2017-08-02
[ [ "Perkins", "Walton A.", "" ] ]
With the advent of the ability to create and study antihydrogen, we think it is appropriate to consider the possibility that antiphotons might not be identical to photons. First of all, we will look at the experimental evidence concerning multiple neutral pions and multiple photons. Because of its internal structure, the neutral kaon is not identical to its antiparticle. We will consider internal structures for the neutral pion and photon for which the antiparticle differs from the particle. Interestingly, the antiphoton thus created from neutrinos does not interact with electrons because its neutrinos have the wrong helicity.
1303.3357
Narendra Sahu
Rupak Dutta, Upender Ch, Anjan K. Giri and Narendra Sahu
Perturbative Bottom-up Approach for Neutrino Mass Matrix in Light of Large \theta_{13} and Role of Lightest Neutrino Mass
26 pages, 42 eps figures, revtex (references are added, more discussions are added in section-III)
null
10.1142/S0217751X14501139
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the role of lightest neutrino mass (m_0) in the neutrino mass matrix, defined in a flavor basis, through a bottom-up approach using the current neutrino oscillation data. We find that if m_0 < 10^{-3} eV, then the deviation \delta M_\nu in the neutrino mass matrix from a tree-level, say tribimaximal neutrino mass matrix, does not depend on m_0. As a result \delta M_\nu's are exactly predicted in terms of the experimentally determined quantities such as solar and atmospheric mass squared differences and the mixing angles. On the other hand for m_0 \gsim 10^{-3} eV, \delta M_\nu strongly depends on m_0 and hence can not be determined within the knowledge of oscillation parameters alone. In this limit, we provide an exponential parameterization for \delta M_\nu for all values of m_0 such that it can factorize the m_0 dependency of \delta M_\nu from rest of the oscillation parameters. This helps us in finding \delta M_\nu as a function of the solar and atmospheric mass squared differences and the mixing angles for all values of m_0. We use this information to build up a model of neutrino masses and mixings in a top-down scenario which can predict large \theta_{13} perturbatively.
[ { "created": "Thu, 14 Mar 2013 06:16:42 GMT", "version": "v1" }, { "created": "Tue, 1 Oct 2013 06:13:45 GMT", "version": "v2" } ]
2015-06-15
[ [ "Dutta", "Rupak", "" ], [ "Ch", "Upender", "" ], [ "Giri", "Anjan K.", "" ], [ "Sahu", "Narendra", "" ] ]
We discuss the role of lightest neutrino mass (m_0) in the neutrino mass matrix, defined in a flavor basis, through a bottom-up approach using the current neutrino oscillation data. We find that if m_0 < 10^{-3} eV, then the deviation \delta M_\nu in the neutrino mass matrix from a tree-level, say tribimaximal neutrino mass matrix, does not depend on m_0. As a result \delta M_\nu's are exactly predicted in terms of the experimentally determined quantities such as solar and atmospheric mass squared differences and the mixing angles. On the other hand for m_0 \gsim 10^{-3} eV, \delta M_\nu strongly depends on m_0 and hence can not be determined within the knowledge of oscillation parameters alone. In this limit, we provide an exponential parameterization for \delta M_\nu for all values of m_0 such that it can factorize the m_0 dependency of \delta M_\nu from rest of the oscillation parameters. This helps us in finding \delta M_\nu as a function of the solar and atmospheric mass squared differences and the mixing angles for all values of m_0. We use this information to build up a model of neutrino masses and mixings in a top-down scenario which can predict large \theta_{13} perturbatively.
1107.2666
Ian Shoemaker
Michael L. Graesser, Ian M. Shoemaker, and Luca Vecchi
A dark force for baryons
24 pages + appendices + references, 7 figures
null
null
LA-UR-11-10573
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest the existence of a fundamental connection between baryonic and dark matter. This is motivated by both the stability of these two types of matter as well as the observed similarity of their present-day densities. A unified genesis of baryonic and dark matter is natural in models in which the baryon number is promoted to a spontaneously broken local gauge symmetry. This is illustrated in a specific class of SUSY models using the Affleck-Dine mechanism. The dark matter candidate in these scenarios is charged under the baryon gauge symmetry and must have a mass around the GeV scale to give the correct present-day abundance. We discuss constraints from B-factories, LEP, mono-jet searches at the Tevatron, and dark matter direct detection experiments. A baryonic dark force is shown to be consistent with all data for mediators as light as the GeV scale.
[ { "created": "Wed, 13 Jul 2011 20:25:48 GMT", "version": "v1" } ]
2011-07-15
[ [ "Graesser", "Michael L.", "" ], [ "Shoemaker", "Ian M.", "" ], [ "Vecchi", "Luca", "" ] ]
We suggest the existence of a fundamental connection between baryonic and dark matter. This is motivated by both the stability of these two types of matter as well as the observed similarity of their present-day densities. A unified genesis of baryonic and dark matter is natural in models in which the baryon number is promoted to a spontaneously broken local gauge symmetry. This is illustrated in a specific class of SUSY models using the Affleck-Dine mechanism. The dark matter candidate in these scenarios is charged under the baryon gauge symmetry and must have a mass around the GeV scale to give the correct present-day abundance. We discuss constraints from B-factories, LEP, mono-jet searches at the Tevatron, and dark matter direct detection experiments. A baryonic dark force is shown to be consistent with all data for mediators as light as the GeV scale.
hep-ph/9411426
null
Christopher T. Hill
Topcolor Assisted Technicolor
15 Pages
Phys.Lett.B345:483-489,1995
10.1016/0370-2693(94)01660-5
FERMILAB-PUB-94/395
hep-ph
null
A condensate, $\overline{t}t$, arising from $O(TeV)$ scale ``topcolor,'' in addition to technicolor (and ETC) may naturally explain the gauge hierarchy, the large top quark mass, and contains a rich system of testable consequences. A triplet of strongly coupled pseudo--Nambu--Goldstone bosons, ``top-pions,'' near the top mass scale is a generic prediction of the models. A new class of technicolor schemes and associated phenomenology is suggested in this approach.
[ { "created": "Tue, 29 Nov 1994 20:45:52 GMT", "version": "v1" }, { "created": "Fri, 2 Dec 1994 15:32:10 GMT", "version": "v2" } ]
2011-01-27
[ [ "Hill", "Christopher T.", "" ] ]
A condensate, $\overline{t}t$, arising from $O(TeV)$ scale ``topcolor,'' in addition to technicolor (and ETC) may naturally explain the gauge hierarchy, the large top quark mass, and contains a rich system of testable consequences. A triplet of strongly coupled pseudo--Nambu--Goldstone bosons, ``top-pions,'' near the top mass scale is a generic prediction of the models. A new class of technicolor schemes and associated phenomenology is suggested in this approach.
hep-ph/0610359
Luis Anchordoqui
Luis A. Anchordoqui, Matthew M. Glenz, and Leonard Parker
Black Holes at the IceCube Neutrino Telescope
Matching version to be published in Phys. Rev. D
Phys.Rev.D75:024011,2007
10.1103/PhysRevD.75.024011
null
hep-ph
null
If the fundamental Planck scale is about a TeV and the cosmic neutrino flux is at the Waxman-Bahcall level, quantum black holes are created daily in the Antarctic ice-cap. We re-examine the prospects for observing such black holes with the IceCube neutrino-detection experiment. To this end, we first revise the black hole production rate by incorporating the effects of inelasticty, i.e., the energy radiated in gravitational waves by the multipole moments of the incoming shock waves. After that we study in detail the process of Hawking evaporation accounting for the black hole's large momentum in the lab system. We derive the energy spectrum of the Planckian cloud which is swept forward with a large, O (10^6), Lorentz factor. (It is noteworthy that the boosted thermal spectrum is also relevant for the study of near-extremal supersymmetric black holes, which could be copiously produced at the LHC.) In the semiclassical regime, we estimate the average energy of the boosted particles to be less than 20% the energy of the neutrino-progenitor. Armed with such a constraint, we determine the discovery reach of IceCube by tagging on "soft" (relative to what one would expect from charged current standard model processes) muons escaping the electromagnetic shower bubble produced by the black hole's light descendants. The statistically significant 5-sigma excess extends up to a quantum gravity scale ~ 1.3 TeV.
[ { "created": "Fri, 27 Oct 2006 10:19:57 GMT", "version": "v1" }, { "created": "Fri, 3 Nov 2006 22:22:42 GMT", "version": "v2" }, { "created": "Thu, 14 Dec 2006 21:59:44 GMT", "version": "v3" } ]
2008-11-26
[ [ "Anchordoqui", "Luis A.", "" ], [ "Glenz", "Matthew M.", "" ], [ "Parker", "Leonard", "" ] ]
If the fundamental Planck scale is about a TeV and the cosmic neutrino flux is at the Waxman-Bahcall level, quantum black holes are created daily in the Antarctic ice-cap. We re-examine the prospects for observing such black holes with the IceCube neutrino-detection experiment. To this end, we first revise the black hole production rate by incorporating the effects of inelasticty, i.e., the energy radiated in gravitational waves by the multipole moments of the incoming shock waves. After that we study in detail the process of Hawking evaporation accounting for the black hole's large momentum in the lab system. We derive the energy spectrum of the Planckian cloud which is swept forward with a large, O (10^6), Lorentz factor. (It is noteworthy that the boosted thermal spectrum is also relevant for the study of near-extremal supersymmetric black holes, which could be copiously produced at the LHC.) In the semiclassical regime, we estimate the average energy of the boosted particles to be less than 20% the energy of the neutrino-progenitor. Armed with such a constraint, we determine the discovery reach of IceCube by tagging on "soft" (relative to what one would expect from charged current standard model processes) muons escaping the electromagnetic shower bubble produced by the black hole's light descendants. The statistically significant 5-sigma excess extends up to a quantum gravity scale ~ 1.3 TeV.
2104.08814
Gang Yang
Gang Yang, Jialun Ping, Jorge Segovia
Exotic resonances of fully-heavy tetraquarks in a lattice-QCD insipired quark model
24 pages, 19 figures, 27 tables
Phys. Rev. D 104, 014006 (2021)
10.1103/PhysRevD.104.014006
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
Fully-heavy tetraquark states, i.e. $cc\bar{c}\bar{c}$, $bb\bar{b}\bar{b}$, $bb\bar{c}\bar{c}$ ($cc\bar{b}\bar{b}$), $cb\bar{c}\bar{c}$, $cb\bar{b}\bar{b}$, and $cb\bar{c}\bar{b}$, are systematically investigated by means of a non-relativistic quark model based on lattice-QCD studies of the two-body $Q\bar{Q}$ interaction, which exhibits a spin-independent Cornell potential along with a spin-spin term. The four-body problem is solved using the Gaussian expansion method; additionally, the so-called complex scaling technique is employed so that bound, resonance, and scattering states can be treated on the same footing. Moreover, a complete set of four-body configurations, including meson-meson, diquark-antidiquark, and K-type configurations, as well as their couplings, are considered for spin-parity quantum numbers $J^{P(C)}=0^{+(+)}$, $1^{+(\pm)}$, and $2^{+(+)}$ in the $S$-wave channel. Several narrow resonances, with two-meson strong decay widths less than 30 MeV, are found in all of the tetraquark systems studied. Particularly, the fully-charm resonances recently reported by the LHCb Collaboration, at the energy range between 6.2 and 7.2 GeV in the di-$J/\psi$ invariant spectrum, can be well identified in our calculation. Focusing on the fully-bottom tetraquark spectrum, resonances with masses between 18.9 and 19.6 GeV are found. For the remaining charm-bottom cases, the masses are obtained within a energy region from 9.8 GeV to 16.4 GeV. All these predicted resonances can be further examined in future experiments.
[ { "created": "Sun, 18 Apr 2021 10:59:46 GMT", "version": "v1" } ]
2021-07-14
[ [ "Yang", "Gang", "" ], [ "Ping", "Jialun", "" ], [ "Segovia", "Jorge", "" ] ]
Fully-heavy tetraquark states, i.e. $cc\bar{c}\bar{c}$, $bb\bar{b}\bar{b}$, $bb\bar{c}\bar{c}$ ($cc\bar{b}\bar{b}$), $cb\bar{c}\bar{c}$, $cb\bar{b}\bar{b}$, and $cb\bar{c}\bar{b}$, are systematically investigated by means of a non-relativistic quark model based on lattice-QCD studies of the two-body $Q\bar{Q}$ interaction, which exhibits a spin-independent Cornell potential along with a spin-spin term. The four-body problem is solved using the Gaussian expansion method; additionally, the so-called complex scaling technique is employed so that bound, resonance, and scattering states can be treated on the same footing. Moreover, a complete set of four-body configurations, including meson-meson, diquark-antidiquark, and K-type configurations, as well as their couplings, are considered for spin-parity quantum numbers $J^{P(C)}=0^{+(+)}$, $1^{+(\pm)}$, and $2^{+(+)}$ in the $S$-wave channel. Several narrow resonances, with two-meson strong decay widths less than 30 MeV, are found in all of the tetraquark systems studied. Particularly, the fully-charm resonances recently reported by the LHCb Collaboration, at the energy range between 6.2 and 7.2 GeV in the di-$J/\psi$ invariant spectrum, can be well identified in our calculation. Focusing on the fully-bottom tetraquark spectrum, resonances with masses between 18.9 and 19.6 GeV are found. For the remaining charm-bottom cases, the masses are obtained within a energy region from 9.8 GeV to 16.4 GeV. All these predicted resonances can be further examined in future experiments.
1203.3196
Alexander Merle
Jonas de Woul, Alexander Merle, Tommy Ohlsson
Establishing Analogies between the Physics of Extra Dimensions and Carbon Nanotubes
5 pages, 1 figure; references updated, title changed according to referee's suggestion; content matches published version
null
10.1016/j.physletb.2012.06.047
null
hep-ph cond-mat.mes-hall
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out a conceptual analogy between the physics of extra spatial dimensions and the physics of carbon nanotubes which arises for principle reasons, although the corresponding energy scales are at least ten orders of magnitude apart. For low energies, one can apply the Kaluza-Klein description to both types of systems, leading to two completely different but consistent interpretations of the underlying physics. In particular, we discuss in detail the Kaluza-Klein description of armchair and zig-zag carbon nanotubes. Furthermore, we describe how certain experimental results for carbon nanotubes could be re-interpreted in terms of the Kaluza-Klein description. Finally, we present ideas for new measurements that could allow to probe concepts of models with extra spatial dimensions in table-top experiments, providing further links between condensed matter and particle physics.
[ { "created": "Wed, 14 Mar 2012 20:00:03 GMT", "version": "v1" }, { "created": "Thu, 5 Jul 2012 14:55:06 GMT", "version": "v2" } ]
2012-07-06
[ [ "de Woul", "Jonas", "" ], [ "Merle", "Alexander", "" ], [ "Ohlsson", "Tommy", "" ] ]
We point out a conceptual analogy between the physics of extra spatial dimensions and the physics of carbon nanotubes which arises for principle reasons, although the corresponding energy scales are at least ten orders of magnitude apart. For low energies, one can apply the Kaluza-Klein description to both types of systems, leading to two completely different but consistent interpretations of the underlying physics. In particular, we discuss in detail the Kaluza-Klein description of armchair and zig-zag carbon nanotubes. Furthermore, we describe how certain experimental results for carbon nanotubes could be re-interpreted in terms of the Kaluza-Klein description. Finally, we present ideas for new measurements that could allow to probe concepts of models with extra spatial dimensions in table-top experiments, providing further links between condensed matter and particle physics.
1501.05058
Daisuke Nomura
Keisuke Nakamura and Daisuke Nomura
Charged Lepton Flavor Violation in the Semi-Constrained NMSSM with Right-Handed Neutrinos
16 pages, 3 figures. v2: reference added, typos corrected. v3: put more emphasis on the difference from the MSSM + \nu_R model, reference added, typos corrected, version to appear in Phys. Lett. B
Phys. Lett. B 746 (2015) 396-405
10.1016/j.physletb.2015.05.028
TU-989, YITP-14-108
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the \mu \to e \gamma decay in the Z_3-invariant next-to-minimal supersymmetric (SUSY) Standard Model (NMSSM) with superheavy right-handed neutrinos. We assume that the soft SUSY breaking parameters are generated at the GUT scale, not universally as in the minimal supergravity scenario but in such a way that those soft parameters which are specific to the NMSSM can differ from the soft parameters which involve only the MSSM fields while keeping the universality at the GUT scale within the soft parameters for the MSSM and right-handed neutrino fields. We call this type of boundary conditions "semi-constrained". In this model, the lepton-flavor-violating off-diagonal elements of the slepton mass matrix are induced by radiative corrections from the neutrino Yukawa couplings, just like as in the MSSM extended with the right-handed neutrinos, and these off-diagonal elements induce sizable rates of \mu \to e \gamma depending on the parameter space. Since this model has more free parameters than the MSSM, the parameter region favored from the Higgs boson mass can slightly differ from that in the MSSM. We show that there is a parameter region in which the \mu \to e \gamma decay can be observable in the near future even if the SUSY mass scale is about 4 TeV.
[ { "created": "Wed, 21 Jan 2015 05:13:16 GMT", "version": "v1" }, { "created": "Sat, 24 Jan 2015 05:22:45 GMT", "version": "v2" }, { "created": "Thu, 21 May 2015 07:01:07 GMT", "version": "v3" } ]
2015-05-27
[ [ "Nakamura", "Keisuke", "" ], [ "Nomura", "Daisuke", "" ] ]
We study the \mu \to e \gamma decay in the Z_3-invariant next-to-minimal supersymmetric (SUSY) Standard Model (NMSSM) with superheavy right-handed neutrinos. We assume that the soft SUSY breaking parameters are generated at the GUT scale, not universally as in the minimal supergravity scenario but in such a way that those soft parameters which are specific to the NMSSM can differ from the soft parameters which involve only the MSSM fields while keeping the universality at the GUT scale within the soft parameters for the MSSM and right-handed neutrino fields. We call this type of boundary conditions "semi-constrained". In this model, the lepton-flavor-violating off-diagonal elements of the slepton mass matrix are induced by radiative corrections from the neutrino Yukawa couplings, just like as in the MSSM extended with the right-handed neutrinos, and these off-diagonal elements induce sizable rates of \mu \to e \gamma depending on the parameter space. Since this model has more free parameters than the MSSM, the parameter region favored from the Higgs boson mass can slightly differ from that in the MSSM. We show that there is a parameter region in which the \mu \to e \gamma decay can be observable in the near future even if the SUSY mass scale is about 4 TeV.
hep-ph/0509067
Andrea Piccione
Andrea Piccione, Joan Rojo (for the NNPDF Collaboration)
Neural network approach to parton distributions fitting
4 pages, 5 eps figures. Talk given by Andrea Piccione at the "X International Workshop on Advanced Computing and Analysis Techniques in Physics Research", ACAT 2005, DESY-Zeuthen, Germany, 22-27 May 2005. Corrected fig. 4
Nucl.Instrum.Meth. A559 (2006) 203-206
10.1016/j.nima.2005.11.206
null
hep-ph
null
We will show an application of neural networks to extract information on the structure of hadrons. A Monte Carlo over experimental data is performed to correctly reproduce data errors and correlations. A neural network is then trained on each Monte Carlo replica via a genetic algorithm. Results on the proton and deuteron structure functions, and on the nonsinglet parton distribution will be shown.
[ { "created": "Wed, 7 Sep 2005 13:23:36 GMT", "version": "v1" }, { "created": "Tue, 18 Oct 2005 14:33:00 GMT", "version": "v2" } ]
2019-08-14
[ [ "Piccione", "Andrea", "", "for the NNPDF Collaboration" ], [ "Rojo", "Joan", "", "for the NNPDF Collaboration" ] ]
We will show an application of neural networks to extract information on the structure of hadrons. A Monte Carlo over experimental data is performed to correctly reproduce data errors and correlations. A neural network is then trained on each Monte Carlo replica via a genetic algorithm. Results on the proton and deuteron structure functions, and on the nonsinglet parton distribution will be shown.
1507.03951
Michael Strickland
Brandon Krouppa, Radoslaw Ryblewski, and Michael Strickland
Bottomonia suppression in 2.76 TeV Pb-Pb collisions
5 pages, 4 figures; tsv files for all plots included in "anc" folder of the submission
Phys. Rev. C 92, 061901 (2015)
10.1103/PhysRevC.92.061901
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the QGP suppression of Upsilon(1s), Upsilon(2s), Upsilon(3s), chi_b1, and chi_b2 states in sqrt(s_NN)=2.76 TeV Pb-Pb collisions. Using the suppression of each of these states, we estimate the inclusive R_AA for the Upsilon(1s) and Upsilon(2s) states as a function of N_part, y, and p_T including the effect of excited state feed down. We find that our model provides a reasonable description of preliminary CMS results for the N_part-, y-, and p_T-dependence of R_AA for both the Upsilon(1s) and Upsilon(2s). Comparing to our previous model predictions, we find a flatter rapidity dependence, thereby reducing some of the tension between our model and ALICE forward-rapidity results for Upsilon(1s) suppression.
[ { "created": "Tue, 14 Jul 2015 17:54:47 GMT", "version": "v1" } ]
2015-12-23
[ [ "Krouppa", "Brandon", "" ], [ "Ryblewski", "Radoslaw", "" ], [ "Strickland", "Michael", "" ] ]
We compute the QGP suppression of Upsilon(1s), Upsilon(2s), Upsilon(3s), chi_b1, and chi_b2 states in sqrt(s_NN)=2.76 TeV Pb-Pb collisions. Using the suppression of each of these states, we estimate the inclusive R_AA for the Upsilon(1s) and Upsilon(2s) states as a function of N_part, y, and p_T including the effect of excited state feed down. We find that our model provides a reasonable description of preliminary CMS results for the N_part-, y-, and p_T-dependence of R_AA for both the Upsilon(1s) and Upsilon(2s). Comparing to our previous model predictions, we find a flatter rapidity dependence, thereby reducing some of the tension between our model and ALICE forward-rapidity results for Upsilon(1s) suppression.
hep-ph/0603171
Christopher Gorham Lester
Christopher G. Lester
Constrained invariant mass distributions in cascade decays. The shape of the "$m_{qll}$-threshold" and similar distributions
12 pages, 3 figures
Phys.Lett.B655:39-44,2007
10.1016/j.physletb.2007.08.061
CAVENDISH-HEP-2006/09
hep-ph
null
Considering the cascade decay $D\to c C \to c b B \to c b a A$ in which $D,C,B,A$ are massive particles and $c,b,a$ are massless particles, we determine for the first time the shape of the distribution of the invariant mass of the three massless particles $m_{abc}$ for the sub-set of decays in which the invariant mass $m_{ab}$ of the last two particles in the chain is (optionally) constrained to lie inside an arbitrary interval, $m_{ab} \in [ m_{ab}^\text{cut min}, m_{ab}^\text{cut max}]$. An example of an experimentally important distribution of this kind is the ``$m_{qll}$ threshold'' -- which is the distribution of the combined invariant mass of the visible standard model particles radiated from the hypothesised decay of a squark to the lightest neutralino via successive two body decay,: $\squark \to q \ntlinoTwo \to q l \slepton \to q l l \ntlinoOne $, in which the experimenter requires additionally that $m_{ll}$ be greater than ${m_{ll}^{max}}/\sqrt{2}$. The location of the ``foot'' of this distribution is often used to constrain sparticle mass scales. The new results presented here permit the location of this foot to be better understood as the shape of the distribution is derived. The effects of varying the position of the $m_{ll}$ cut(s) may now be seen more easily.
[ { "created": "Wed, 22 Mar 2006 18:03:38 GMT", "version": "v1" }, { "created": "Wed, 22 Mar 2006 22:03:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Lester", "Christopher G.", "" ] ]
Considering the cascade decay $D\to c C \to c b B \to c b a A$ in which $D,C,B,A$ are massive particles and $c,b,a$ are massless particles, we determine for the first time the shape of the distribution of the invariant mass of the three massless particles $m_{abc}$ for the sub-set of decays in which the invariant mass $m_{ab}$ of the last two particles in the chain is (optionally) constrained to lie inside an arbitrary interval, $m_{ab} \in [ m_{ab}^\text{cut min}, m_{ab}^\text{cut max}]$. An example of an experimentally important distribution of this kind is the ``$m_{qll}$ threshold'' -- which is the distribution of the combined invariant mass of the visible standard model particles radiated from the hypothesised decay of a squark to the lightest neutralino via successive two body decay,: $\squark \to q \ntlinoTwo \to q l \slepton \to q l l \ntlinoOne $, in which the experimenter requires additionally that $m_{ll}$ be greater than ${m_{ll}^{max}}/\sqrt{2}$. The location of the ``foot'' of this distribution is often used to constrain sparticle mass scales. The new results presented here permit the location of this foot to be better understood as the shape of the distribution is derived. The effects of varying the position of the $m_{ll}$ cut(s) may now be seen more easily.
hep-ph/9412331
null
M. M. Guzzo, O. L. G. Peres, V. Pleitez and R. Zukanovich Funchal
Adiabatic matter effect with three generation neutrinos and the solar neutrino problem
11 pages, Revtex 3.0, two ps figures appended
null
null
IFT-P.003/95; DCR-TH 05/94; IFUSP-P/1133
hep-ph
null
We find an exact analytic solution for the time evolution of a three Dirac neutrino system adiabatically oscillating in matter, constructing explicitly the relevant $3\times 3$ mixing matrix in matter. Using this result we investigate the solar neutrino data in a scenario where the neutrino masses are such that $m_1\alt m_2\ll m_3$, taking into account several phenomenological constraints on neutrino mixing angles and masses. A solution of the solar neutrino problem for large values of the parameter $\delta m^2=m_2^2-m_1^2$ which are not usually associated with a resonance is found. This is an essentially three-generation effect.
[ { "created": "Tue, 20 Dec 1994 10:53:21 GMT", "version": "v1" } ]
2009-09-25
[ [ "Guzzo", "M. M.", "" ], [ "Peres", "O. L. G.", "" ], [ "Pleitez", "V.", "" ], [ "Funchal", "R. Zukanovich", "" ] ]
We find an exact analytic solution for the time evolution of a three Dirac neutrino system adiabatically oscillating in matter, constructing explicitly the relevant $3\times 3$ mixing matrix in matter. Using this result we investigate the solar neutrino data in a scenario where the neutrino masses are such that $m_1\alt m_2\ll m_3$, taking into account several phenomenological constraints on neutrino mixing angles and masses. A solution of the solar neutrino problem for large values of the parameter $\delta m^2=m_2^2-m_1^2$ which are not usually associated with a resonance is found. This is an essentially three-generation effect.
2301.06104
Di Wang
Di Wang
Generation of isospin sum rules in heavy hadron weak decays
26 pages, Version published in JHEP
JHEP 05 (2023) 064
10.1007/JHEP05(2023)064
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Isospin symmetry is the most precise flavor symmetry. In this work, we propose an approach to generate isospin sum rules for heavy hadron decays without the Wigner-Eckhart invariants. The effective Hamiltonian of heavy quark weak decay is fully invariant under a series of isospin lowering operators $I_-^n$ and then the isospin sum rules can be generated through several master formulas. It provides a systematic way to study the isospin symmetry of $c$- and $b$-hadron weak decays. The theoretical framework of this approach is presented in detail with the nonleptonic decays of $D$ and $B$ mesons as examples. In addition, the $V$-/$U$-spin sum rules are derived in a similar algorithm by replacing $I_-^n$ with $V_-^n$/$U_-^n$.
[ { "created": "Sun, 15 Jan 2023 14:24:34 GMT", "version": "v1" }, { "created": "Wed, 10 May 2023 09:31:24 GMT", "version": "v2" } ]
2023-05-11
[ [ "Wang", "Di", "" ] ]
Isospin symmetry is the most precise flavor symmetry. In this work, we propose an approach to generate isospin sum rules for heavy hadron decays without the Wigner-Eckhart invariants. The effective Hamiltonian of heavy quark weak decay is fully invariant under a series of isospin lowering operators $I_-^n$ and then the isospin sum rules can be generated through several master formulas. It provides a systematic way to study the isospin symmetry of $c$- and $b$-hadron weak decays. The theoretical framework of this approach is presented in detail with the nonleptonic decays of $D$ and $B$ mesons as examples. In addition, the $V$-/$U$-spin sum rules are derived in a similar algorithm by replacing $I_-^n$ with $V_-^n$/$U_-^n$.
1912.01758
Sandra Robles
M. E. Cabrera, J. A. Casas, A. Delgado, S. Robles
Generalized Blind Spots for Dark Matter Direct Detection in the 2HDM
16 pages, 5 figures, 2 tables. References added, matches JHEP published version
JHEP 02 (2020) 166
10.1007/JHEP02(2020)166
IFT-UAM/CSIC-19-160
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the presence of generalized blind spots, i.e. regions of the parameter space where the spin-independent cross section for dark matter direct detection is suppressed, in the context of a generic 2HDM and a minimal fermionic Higgs-portal dark sector. To this end, we derive analytical expressions for the couplings of the dark matter to the light and heavy Higgses, and thus for the blind spot solutions. Unlike the case of a standard Higgs sector, blind spots can occur even without a cancellation between different contributions, while keeping unsuppressed and efficient the annihilation processes in the early Universe involving Higgs states. As a consequence, the allowed parameter space is dramatically enhanced.
[ { "created": "Wed, 4 Dec 2019 01:22:07 GMT", "version": "v1" }, { "created": "Thu, 27 Feb 2020 07:07:16 GMT", "version": "v2" } ]
2020-02-28
[ [ "Cabrera", "M. E.", "" ], [ "Casas", "J. A.", "" ], [ "Delgado", "A.", "" ], [ "Robles", "S.", "" ] ]
In this paper we study the presence of generalized blind spots, i.e. regions of the parameter space where the spin-independent cross section for dark matter direct detection is suppressed, in the context of a generic 2HDM and a minimal fermionic Higgs-portal dark sector. To this end, we derive analytical expressions for the couplings of the dark matter to the light and heavy Higgses, and thus for the blind spot solutions. Unlike the case of a standard Higgs sector, blind spots can occur even without a cancellation between different contributions, while keeping unsuppressed and efficient the annihilation processes in the early Universe involving Higgs states. As a consequence, the allowed parameter space is dramatically enhanced.
0907.3607
Lusaka Bhattacharya
Lusaka Bhattacharya and Pradip Roy
Rapidity distribution of photons from an anisotropic Quark-Gluon-Plasma
19 pages, 18 eps figures, Accepted for publication in Physical Review C
Phys.Rev.C81:054904,2010
10.1103/PhysRevC.81.054904
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate rapidity distribution of photons due to Compton and annihilation processes from {\em Quark Gluon Plasma} (QGP) with pre-equilibrium momentum-space anisotropy. We also include contributions from hadronic matter with late stage transverse expansion. A phenomenological model has been used for the time evolution of hard momentum scale $p_{\rm hard}(\tau)$ and anisotropy parameter $\xi(\tau)$. As a result of pre-equilibrium momentum-space anisotropy, we find significant modification of photons rapidity distribution. For example, with {\em fixed initial condition} (FIC) {\em free-streaming} ($\delta=2$) interpolating model we observe significant enhancement of photon rapidity distribution at fixed $p_T$, where as for FIC {\em collisionally-broadened} ($\delta=2/3$) interpolating model the yield increases till $y \sim 1$. Beyond that suppression is observed. With {\em fixed final multiplicity} (FFM) {\em free-streaming} interpolating model we predict enhancement of photon yield which is less than the case of FIC. Suppression is always observed for FFM {\em collisionally-broadened} interpolating model.
[ { "created": "Tue, 21 Jul 2009 10:27:49 GMT", "version": "v1" }, { "created": "Wed, 5 May 2010 06:46:56 GMT", "version": "v2" } ]
2014-11-20
[ [ "Bhattacharya", "Lusaka", "" ], [ "Roy", "Pradip", "" ] ]
We calculate rapidity distribution of photons due to Compton and annihilation processes from {\em Quark Gluon Plasma} (QGP) with pre-equilibrium momentum-space anisotropy. We also include contributions from hadronic matter with late stage transverse expansion. A phenomenological model has been used for the time evolution of hard momentum scale $p_{\rm hard}(\tau)$ and anisotropy parameter $\xi(\tau)$. As a result of pre-equilibrium momentum-space anisotropy, we find significant modification of photons rapidity distribution. For example, with {\em fixed initial condition} (FIC) {\em free-streaming} ($\delta=2$) interpolating model we observe significant enhancement of photon rapidity distribution at fixed $p_T$, where as for FIC {\em collisionally-broadened} ($\delta=2/3$) interpolating model the yield increases till $y \sim 1$. Beyond that suppression is observed. With {\em fixed final multiplicity} (FFM) {\em free-streaming} interpolating model we predict enhancement of photon yield which is less than the case of FIC. Suppression is always observed for FFM {\em collisionally-broadened} interpolating model.
hep-ph/0509078
Giuseppe Marchesini
Yu.L. Dokshitzer and G. Marchesini
Soft gluons at large angles in hadron collisions
29 pages, pictures generated with feynmf graphic package
JHEP0601:007,2006
10.1088/1126-6708/2006/01/007
Bicocca-FT-05-19, LPTHE-05-23
hep-ph
null
A general discussion is presented of the single logarithmic soft factor that appears in two scale QCD observables in processes involving four partons. We treat it as the ``fifth form factor'', accompanying the four collinear singular Sudakov form factors attached to colliding and outgoing hard partons. The fifth form factor is expressed in terms of the Casimir operators (squared colour charges) of irreducible representations in the crossing $t$- and $u$-channels. As an application we revisit the problem of large angle radiation in $gg\to gg$ and give a relatively simple solution and interpretation of the results. We found an unexpected symmetry of the soft anomalous dimension under exchange of internal and external variables of the problem whose existence calls for explanation.
[ { "created": "Thu, 8 Sep 2005 14:52:29 GMT", "version": "v1" }, { "created": "Sat, 10 Sep 2005 13:27:52 GMT", "version": "v2" } ]
2009-11-11
[ [ "Dokshitzer", "Yu. L.", "" ], [ "Marchesini", "G.", "" ] ]
A general discussion is presented of the single logarithmic soft factor that appears in two scale QCD observables in processes involving four partons. We treat it as the ``fifth form factor'', accompanying the four collinear singular Sudakov form factors attached to colliding and outgoing hard partons. The fifth form factor is expressed in terms of the Casimir operators (squared colour charges) of irreducible representations in the crossing $t$- and $u$-channels. As an application we revisit the problem of large angle radiation in $gg\to gg$ and give a relatively simple solution and interpretation of the results. We found an unexpected symmetry of the soft anomalous dimension under exchange of internal and external variables of the problem whose existence calls for explanation.
hep-ph/9210216
null
Michael Chanowitz
Complementarity of Resonant and Nonresonant Strong WW Scattering at SSC and LHC
8 pages (figures on request by Pony Express), LBL-32938
null
10.1063/1.43426
null
hep-ph
null
Signals and backgrounds for strong $WW$ scattering at the SSC and LHC are considered. Complementarity of resonant signals in the $I=1$ $WZ$ channel and nonresonant signals in the $I=2$ \wpwp channel is illustrated using a chiral lagrangian with a $J=1$ \qrho resonance. Results are presented for purely leptonic final states in the $W^{\pm}Z$, $W^+W^+ + W^-W^-$, and $ZZ$ channels.
[ { "created": "Tue, 6 Oct 1992 18:25:25 GMT", "version": "v1" } ]
2009-10-22
[ [ "Chanowitz", "Michael", "" ] ]
Signals and backgrounds for strong $WW$ scattering at the SSC and LHC are considered. Complementarity of resonant signals in the $I=1$ $WZ$ channel and nonresonant signals in the $I=2$ \wpwp channel is illustrated using a chiral lagrangian with a $J=1$ \qrho resonance. Results are presented for purely leptonic final states in the $W^{\pm}Z$, $W^+W^+ + W^-W^-$, and $ZZ$ channels.
hep-ph/0612245
Ambar Ghosal
Ambar Ghosal
Recent Models of Neutrino Masses and Mixing
11 pages, no figures, Plenary Talk given at DAE-BRNS High Energy Physics Symposium, Indian Institute of Technology, Kharagpur, India,December 2006
null
null
null
hep-ph
null
In this talk, I have reviewed few recent models on neutrino masses and mixing. Particularly, I have emphasised on $A_4$ symmetric models.
[ { "created": "Wed, 20 Dec 2006 08:53:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ghosal", "Ambar", "" ] ]
In this talk, I have reviewed few recent models on neutrino masses and mixing. Particularly, I have emphasised on $A_4$ symmetric models.
hep-ph/0206245
Xing ZhiZhong
Zhi-zhong Xing
A Predictive Ansatz for Neutrino Mixing and Leptogenesis
RevTex 14 pages. More discussions added. Accepted for publication in Phys. Lett. B
Phys.Lett. B545 (2002) 352-360
10.1016/S0370-2693(02)02615-1
BIHEP-TH-2002-26
hep-ph
null
We propose a non-SO(10) modification of the Buchmueller-Wyler ansatz for neutrino mixing and leptogenesis, in which charged lepton, Dirac and Majorana neutrino mass matrices have fewer free parameters. Predictions of this new ansatz for three light neutrino masses, three lepton flavor mixing angles, the neutrinoless double-beta decay and the cosmological matter-antimatter asymmetry are all in very good agreement with current experimental and observational data.
[ { "created": "Tue, 25 Jun 2002 02:57:37 GMT", "version": "v1" }, { "created": "Thu, 29 Aug 2002 00:54:49 GMT", "version": "v2" } ]
2009-11-07
[ [ "Xing", "Zhi-zhong", "" ] ]
We propose a non-SO(10) modification of the Buchmueller-Wyler ansatz for neutrino mixing and leptogenesis, in which charged lepton, Dirac and Majorana neutrino mass matrices have fewer free parameters. Predictions of this new ansatz for three light neutrino masses, three lepton flavor mixing angles, the neutrinoless double-beta decay and the cosmological matter-antimatter asymmetry are all in very good agreement with current experimental and observational data.
hep-ph/9504300
Andre Sopczak
A. Sopczak (PPE Division, CERN)
Status of Higgs Hunting at LEP -- Five Years of Progress
20 pages, 49 figures, PS file
null
null
null
hep-ph
null
New results from general searches for the Higgs boson of the Minimal Standard Model (MSM), and for neutral and charged Higgs bosons of non-minimal Higgs models are reviewed from the four LEP experiments at CERN: ALEPH, DELPHI, L3, and OPAL. Much progress has been made due to the analysis of new data sets. A total of about 13 million hadronic Z decays are recorded from 1989 to 1994. The Higgs boson discovery potential for LEP2 is presented.
[ { "created": "Fri, 14 Apr 1995 01:37:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sopczak", "A.", "", "PPE Division, CERN" ] ]
New results from general searches for the Higgs boson of the Minimal Standard Model (MSM), and for neutral and charged Higgs bosons of non-minimal Higgs models are reviewed from the four LEP experiments at CERN: ALEPH, DELPHI, L3, and OPAL. Much progress has been made due to the analysis of new data sets. A total of about 13 million hadronic Z decays are recorded from 1989 to 1994. The Higgs boson discovery potential for LEP2 is presented.
1404.4873
Ulrich Haisch
Martin Gorbahn and Ulrich Haisch
Searching for t->c(u)h with dipole moments
18 pages, 2 figures; v2: references added and typos corrected; coincides with version to be published in JHEP
null
10.1007/JHEP06(2014)033
LTH 1006
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A discovery of flavour-changing Higgs-boson decays would constitute an undeniable signal of new physics. We derive model-independent constraints on the tch and tuh couplings that arise from the bounds on hadronic electric dipole moments. Comparisons of the present and future sensitivities with both the direct LHC constraints and the indirect limits from D-meson physics are also presented.
[ { "created": "Fri, 18 Apr 2014 20:00:03 GMT", "version": "v1" }, { "created": "Thu, 5 Jun 2014 14:40:03 GMT", "version": "v2" } ]
2015-06-19
[ [ "Gorbahn", "Martin", "" ], [ "Haisch", "Ulrich", "" ] ]
A discovery of flavour-changing Higgs-boson decays would constitute an undeniable signal of new physics. We derive model-independent constraints on the tch and tuh couplings that arise from the bounds on hadronic electric dipole moments. Comparisons of the present and future sensitivities with both the direct LHC constraints and the indirect limits from D-meson physics are also presented.
1501.04161
Ryosuke Sato
Tomohiro Abe and Ryosuke Sato
Quantum corrections to the spin-independent cross section of the inert doublet dark matter
38 pages, 18 figures
null
null
KEK-TH-1787
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The inert Higgs doublet model contains a stable neutral boson as a candidate of dark matter. We calculate cross section for spin-independent scattering of the dark matter on nucleon. We take into account electroweak and scalar quartic interactions, and evaluate effects of scattering with quarks at one-loop level and with gluon at two-loop level. These contributions give an important effect for the dark matter mass to be around m_h/2, because a coupling with the standard model Higgs boson which gives the leading order contribution should be suppressed to reproduce the correct amount of the thermal relic abundance in this mass region. In particular, we show that the dark matter self coupling changes the value of the spin-independent cross section significantly.
[ { "created": "Sat, 17 Jan 2015 05:46:00 GMT", "version": "v1" } ]
2015-01-20
[ [ "Abe", "Tomohiro", "" ], [ "Sato", "Ryosuke", "" ] ]
The inert Higgs doublet model contains a stable neutral boson as a candidate of dark matter. We calculate cross section for spin-independent scattering of the dark matter on nucleon. We take into account electroweak and scalar quartic interactions, and evaluate effects of scattering with quarks at one-loop level and with gluon at two-loop level. These contributions give an important effect for the dark matter mass to be around m_h/2, because a coupling with the standard model Higgs boson which gives the leading order contribution should be suppressed to reproduce the correct amount of the thermal relic abundance in this mass region. In particular, we show that the dark matter self coupling changes the value of the spin-independent cross section significantly.
hep-ph/9811408
Luciene Pontes Freitas
O. L. G. Peres, L. P. Freitas and R. Zukanovich Funchal
Limits on Majorana Neutrinos from Recent Experimental Data
19 pages, 2 figures
Phys.Rev. D59 (1999) 113014
10.1103/PhysRevD.59.113014
null
hep-ph
null
We investigate the sensitivity of some weak processes to the simplest extension of the Standard Model with Majorana neutrinos mixing in the leptonic sector. Values for mixing angles and masses compatible with several experimental accelerator data and the most recent neutrinoless double--$\beta$ decay limit were found.
[ { "created": "Thu, 19 Nov 1998 18:49:19 GMT", "version": "v1" }, { "created": "Mon, 30 Nov 1998 17:35:55 GMT", "version": "v2" }, { "created": "Thu, 25 Feb 1999 12:40:09 GMT", "version": "v3" } ]
2009-10-31
[ [ "Peres", "O. L. G.", "" ], [ "Freitas", "L. P.", "" ], [ "Funchal", "R. Zukanovich", "" ] ]
We investigate the sensitivity of some weak processes to the simplest extension of the Standard Model with Majorana neutrinos mixing in the leptonic sector. Values for mixing angles and masses compatible with several experimental accelerator data and the most recent neutrinoless double--$\beta$ decay limit were found.
hep-ph/9307227
S. Keller
U. Baur, F. Halzen, S.Keller, M. L. Mangano, and K. Riesselmann
Measurement of the Strange Quark Distribution Function in W + Charm Quark Events
Latex, 9 pages + 2 postscript figures encoded with uufile, FSU-HEP-930608, MAD/TH/93/4, MAD/PH/769. A postscript file with text and embedded figures is available via anonymous ftp at hepsg1.physics.fsu.edu, file is /pub/keller/fsu-hep-930608.ps
null
null
null
hep-ph
null
We investigate the prospects of measuring the strange quark distribution function at the Tevatron, using $W$ plus charm quark events. The $W$ plus charm quark signal produced by strange quark--gluon fusion, $sg\rightarrow W^-c$ and $\bar sg\rightarrow W^+\bar c$, is approximately 5\% of the inclusive $W+1$ jet cross section for jets with a transverse momentum $p_T(j)>10$~GeV. We study the sensitivity of the $W$ plus charm quark cross section to the parametrization of the strange quark distribution function, and evaluate the various background processes. Strategies to identify charm quarks in CDF and D$0\llap/$ are briefly described.
[ { "created": "Tue, 6 Jul 1993 19:03:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baur", "U.", "" ], [ "Halzen", "F.", "" ], [ "Keller", "S.", "" ], [ "Mangano", "M. L.", "" ], [ "Riesselmann", "K.", "" ] ]
We investigate the prospects of measuring the strange quark distribution function at the Tevatron, using $W$ plus charm quark events. The $W$ plus charm quark signal produced by strange quark--gluon fusion, $sg\rightarrow W^-c$ and $\bar sg\rightarrow W^+\bar c$, is approximately 5\% of the inclusive $W+1$ jet cross section for jets with a transverse momentum $p_T(j)>10$~GeV. We study the sensitivity of the $W$ plus charm quark cross section to the parametrization of the strange quark distribution function, and evaluate the various background processes. Strategies to identify charm quarks in CDF and D$0\llap/$ are briefly described.
hep-ph/9505243
Mike A. Walker
M.A. Walker (Purdue University)
AN OPERATOR ANALYSIS OF A SUPERSYMMETRIC EFFECTIVE THEORY
20 pages uses standard LaTex format
Int.J.Mod.Phys. A11 (1996) 1007-1018
10.1142/S0217751X9600047X
PURD-TH-95-04
hep-ph
null
An analysis of a $SU(2)_L \times SU(2)_R$ invariant, supersymmetric effective theory is given. The resulting leading and next to leading independent invariants are stated in terms of the underlying Killing vectors and K\"ahler potential. The appendices are devoted to the relationship between this geometrical point of view and the standard unitary matrix formulation.
[ { "created": "Fri, 5 May 1995 20:12:17 GMT", "version": "v1" } ]
2015-06-25
[ [ "Walker", "M. A.", "", "Purdue University" ] ]
An analysis of a $SU(2)_L \times SU(2)_R$ invariant, supersymmetric effective theory is given. The resulting leading and next to leading independent invariants are stated in terms of the underlying Killing vectors and K\"ahler potential. The appendices are devoted to the relationship between this geometrical point of view and the standard unitary matrix formulation.
hep-ph/0407290
Wojciech Broniowski
Wojciech Broniowski, Wojciech Florkowski, Leonid Ya. Glozman
Update of the Hagedorn mass spectrum
4 pages, 4 figures
Phys.Rev. D70 (2004) 117503
10.1103/PhysRevD.70.117503
null
hep-ph
null
We present an update of the Hagedorn hypothesis of the exponential growth of the number of hadronic resonances with mass. We use the newest available experimental data for the non-strange mesons and baryons, as well as fill in some missing states according to the observation that the high-lying states form chiral multiplets. The results show, especially for the case of the mesons, that the Hagedorn growth continues with the increasing mass, with the new states lining up along the exponential growth.
[ { "created": "Sun, 25 Jul 2004 20:12:58 GMT", "version": "v1" } ]
2009-11-10
[ [ "Broniowski", "Wojciech", "" ], [ "Florkowski", "Wojciech", "" ], [ "Glozman", "Leonid Ya.", "" ] ]
We present an update of the Hagedorn hypothesis of the exponential growth of the number of hadronic resonances with mass. We use the newest available experimental data for the non-strange mesons and baryons, as well as fill in some missing states according to the observation that the high-lying states form chiral multiplets. The results show, especially for the case of the mesons, that the Hagedorn growth continues with the increasing mass, with the new states lining up along the exponential growth.
2307.14053
Osamu Seto
Nobuchika Okada and Osamu Seto
Intergenerational gauged $B-L$ model and its implication to muon $g-2$ anomaly and thermal dark matter
20 pages, 6 figures, 3 tables, references added, journal version
Phys. Rev. D 108, 083504 (2023)
10.1103/PhysRevD.108.083504
EPHOU-23-015
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We study the flavor dependent $U(1)_{B_i-L_j}$ models, where an $i$th generation of quarks and $j(\neq i)$th generation of leptons are charged. By solving the anomaly free condition for the matter sector of the SM fermions and three generations of right-handed (RH) neutrinos, we find that the $j$th generation of RH neutrino is not necessarily charged under the $U(1)_{B_i-L_j}$ gauge symmetry with the charge $-1$ and the other (neither $i$th nor $j$th) generation of RH neutrino can also be. As a general solution for the anomaly cancellation conditions, the other two RN neutrinos than the charge $-1$ RH neutrino may have non-vanishing charge and be stable due to the gauge invariance, and hence it is a candidate for dark matter (DM) in our Universe. We apply this result to a $B_3-L_2$ model and consider a light thermal DM and a solution to the muon $g-2$ anomaly. We identify the parameter region to have the DM mass range from MeV to sub-GeV and simultaneously solve the muon $g-2$ anomaly. We also derive the constraints on the gauge kinetic mixing parameter by using the latest Borexino phase-II data.
[ { "created": "Wed, 26 Jul 2023 09:05:02 GMT", "version": "v1" }, { "created": "Tue, 3 Oct 2023 03:19:33 GMT", "version": "v2" } ]
2023-10-04
[ [ "Okada", "Nobuchika", "" ], [ "Seto", "Osamu", "" ] ]
We study the flavor dependent $U(1)_{B_i-L_j}$ models, where an $i$th generation of quarks and $j(\neq i)$th generation of leptons are charged. By solving the anomaly free condition for the matter sector of the SM fermions and three generations of right-handed (RH) neutrinos, we find that the $j$th generation of RH neutrino is not necessarily charged under the $U(1)_{B_i-L_j}$ gauge symmetry with the charge $-1$ and the other (neither $i$th nor $j$th) generation of RH neutrino can also be. As a general solution for the anomaly cancellation conditions, the other two RN neutrinos than the charge $-1$ RH neutrino may have non-vanishing charge and be stable due to the gauge invariance, and hence it is a candidate for dark matter (DM) in our Universe. We apply this result to a $B_3-L_2$ model and consider a light thermal DM and a solution to the muon $g-2$ anomaly. We identify the parameter region to have the DM mass range from MeV to sub-GeV and simultaneously solve the muon $g-2$ anomaly. We also derive the constraints on the gauge kinetic mixing parameter by using the latest Borexino phase-II data.
hep-ph/0008260
Martin McDermott
M. F. McDermott
The dipole picture of small x physics (a summary of the Amirim meeting)
28 pages, latex, 6 figures. Fig. 6 now displayed properly, two minor typos corrected
null
null
null
hep-ph
null
A personal summary of the discussions which took place at the informal meeting in Amirim, Israel from June 1-4 2000, concerning the dipole picture of small-$x$ physics is presented. The broad aim of the meeting was to address the question ``Has HERA reached a new QCD regime (at small $x$) ?''. The new regime in question is the high-density, but weak-coupling, limit of perturbative QCD.
[ { "created": "Thu, 24 Aug 2000 13:35:42 GMT", "version": "v1" }, { "created": "Fri, 25 Aug 2000 12:53:15 GMT", "version": "v2" } ]
2007-05-23
[ [ "McDermott", "M. F.", "" ] ]
A personal summary of the discussions which took place at the informal meeting in Amirim, Israel from June 1-4 2000, concerning the dipole picture of small-$x$ physics is presented. The broad aim of the meeting was to address the question ``Has HERA reached a new QCD regime (at small $x$) ?''. The new regime in question is the high-density, but weak-coupling, limit of perturbative QCD.
1312.5406
Alka Upadhyay
A. Upadhyay, M. Batra
B-meson spectroscopy in heavy hadron chiral perturbation theory
Proceedings of DAE symposium in nuclear physics,vol. 58, 2013
null
null
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The theory of heavy meson masses, in which the symmetries of heavy and light quarks are exploited, can be used to describe the low energy interaction among heavy mesons to a better extent. The spin-flavor symmetry leads to many interesting relations between the properties of hadrons containing a heavy quark. The most direct consequences concern the spectroscopy of such states. We use such symmetries to explore some of the states of B-meson and predictions are found to be in agreement with the experimental data.
[ { "created": "Thu, 19 Dec 2013 05:06:08 GMT", "version": "v1" } ]
2013-12-20
[ [ "Upadhyay", "A.", "" ], [ "Batra", "M.", "" ] ]
The theory of heavy meson masses, in which the symmetries of heavy and light quarks are exploited, can be used to describe the low energy interaction among heavy mesons to a better extent. The spin-flavor symmetry leads to many interesting relations between the properties of hadrons containing a heavy quark. The most direct consequences concern the spectroscopy of such states. We use such symmetries to explore some of the states of B-meson and predictions are found to be in agreement with the experimental data.
hep-ph/9303243
Sanghyun Chang
Sanghyeon Chang, Kiwoon Choi
Constraints from Nucleosynthesis and SN1987A on Majoron Emitting Double Beta Decay
12pages, 1 figure by PicTex, SNUTP 92-87
Phys.Rev.D49:12-15,1994
10.1103/PhysRevD.49.12
null
hep-ph astro-ph
null
We examine whether observable majoron emission in double beta decay can be compatible with the big-bang nucleosynthesis (NS) and the observed neutrino flux from SN1987A. It is found that the NS upper bound on $^4$He abundance implies that the majoron-neutrino Yukawa coupling constant $g\leq 9\times 10^{-6}$ and its maximal value is allowed only when the scalar quartic coupling constant $\lambda$ is extremely small, $\lambda\leq 100g^2$. It is also observed that, although quite less restrictive, SN1987A also provides independent constraints on coupling constants.
[ { "created": "Thu, 11 Mar 1993 06:26:29 GMT", "version": "v1" } ]
2009-12-30
[ [ "Chang", "Sanghyeon", "" ], [ "Choi", "Kiwoon", "" ] ]
We examine whether observable majoron emission in double beta decay can be compatible with the big-bang nucleosynthesis (NS) and the observed neutrino flux from SN1987A. It is found that the NS upper bound on $^4$He abundance implies that the majoron-neutrino Yukawa coupling constant $g\leq 9\times 10^{-6}$ and its maximal value is allowed only when the scalar quartic coupling constant $\lambda$ is extremely small, $\lambda\leq 100g^2$. It is also observed that, although quite less restrictive, SN1987A also provides independent constraints on coupling constants.
2203.07778
Hee Sok Chung
Nora Brambilla, Hee Sok Chung, Antonio Vairo, Xiang-Peng Wang
Production and polarization of $S$-wave quarkonia in potential nonrelativistic QCD
6 pages, 2 figures, 2 tables, minor corrections, version published as a Letter in Phys. Rev. D
Phys. Rev. D 105, L111503 (2022)
10.1103/PhysRevD.105.L111503
TUM-EFT 168/22
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on the potential nonrelativistic QCD formalism, we compute the nonrelativistic QCD long-distance matrix elements (LDMEs) for inclusive production of $S$-wave heavy quarkonia. This greatly reduces the number of nonperturbative unknowns and brings in a substantial enhancement in the predictive power of the nonrelativistic QCD factorization formalism. We obtain improved determinations of the LDMEs and find cross sections and polarizations of $J/\psi$, $\psi(2S)$, and excited $\Upsilon$ states that agree well with LHC data. Our results may have important implications in pinning down the heavy quarkonium production mechanism.
[ { "created": "Tue, 15 Mar 2022 10:58:01 GMT", "version": "v1" }, { "created": "Mon, 27 Jun 2022 05:04:14 GMT", "version": "v2" } ]
2022-06-28
[ [ "Brambilla", "Nora", "" ], [ "Chung", "Hee Sok", "" ], [ "Vairo", "Antonio", "" ], [ "Wang", "Xiang-Peng", "" ] ]
Based on the potential nonrelativistic QCD formalism, we compute the nonrelativistic QCD long-distance matrix elements (LDMEs) for inclusive production of $S$-wave heavy quarkonia. This greatly reduces the number of nonperturbative unknowns and brings in a substantial enhancement in the predictive power of the nonrelativistic QCD factorization formalism. We obtain improved determinations of the LDMEs and find cross sections and polarizations of $J/\psi$, $\psi(2S)$, and excited $\Upsilon$ states that agree well with LHC data. Our results may have important implications in pinning down the heavy quarkonium production mechanism.
hep-ph/0205065
Dan Pirjol
Michael Gronau and Dan Pirjol
Photon polarization in radiative B decays
22 pages, 3 figures, version to appear in Phys. Rev. D
Phys.Rev. D66 (2002) 054008
10.1103/PhysRevD.66.054008
TECHNION-PH-2002-18, UCSD/PTH 02-10
hep-ph hep-ex
null
We study decay distributions in B -> K pi pi gamma, combining contributions from several overlapping resonances in a K pi pi mass range near 1400 MeV, (1^+) K_1(1400), (2^+) K^*_2(1430) and (1^-) K^*(1410). A method is proposed for using these distributions to determine a photon polarization parameter in the effective radiative weak Hamiltonian. This parameter is measured through an up-down asymmetry of the photon direction relative to the K pi pi decay plane. We calculate a dominant up-down asymmetry of 0.33 +- 0.05 from the K1(1400) resonance, which can be measured with about 10^8 B B-bar pairs, thus providing a new test for the Standard Model and a probe for some of its extensions.
[ { "created": "Tue, 7 May 2002 18:10:19 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2002 16:52:56 GMT", "version": "v2" } ]
2009-11-07
[ [ "Gronau", "Michael", "" ], [ "Pirjol", "Dan", "" ] ]
We study decay distributions in B -> K pi pi gamma, combining contributions from several overlapping resonances in a K pi pi mass range near 1400 MeV, (1^+) K_1(1400), (2^+) K^*_2(1430) and (1^-) K^*(1410). A method is proposed for using these distributions to determine a photon polarization parameter in the effective radiative weak Hamiltonian. This parameter is measured through an up-down asymmetry of the photon direction relative to the K pi pi decay plane. We calculate a dominant up-down asymmetry of 0.33 +- 0.05 from the K1(1400) resonance, which can be measured with about 10^8 B B-bar pairs, thus providing a new test for the Standard Model and a probe for some of its extensions.
hep-ph/0011137
Antonio Soares de Castro
A.S. de Castro (1), J. Franklin (2) ((1)UNESP/Campus de Guaratingueta, (2) Temple University)
Some exact solutions of the Dirac equation
4 pages. No figures. Presented in Hadron 2000: International Workshop on Hadron Physics, Caraguatatuba, SP, Brasil, April 2000
null
10.1142/9789812811653_0020
null
hep-ph quant-ph
null
Exact analytic solutions are found to the Dirac equation for a combination of Lorentz scalar and vector Coulombic potentials with additional non-Coulombic parts. An appropriate linear combination of Lorentz scalar and vector non-Coulombic potentials, with the scalar part dominating, can be chosen to give exact analytic Dirac wave functions.
[ { "created": "Thu, 9 Nov 2000 22:24:48 GMT", "version": "v1" } ]
2017-08-23
[ [ "de Castro", "A. S.", "" ], [ "Franklin", "J.", "" ] ]
Exact analytic solutions are found to the Dirac equation for a combination of Lorentz scalar and vector Coulombic potentials with additional non-Coulombic parts. An appropriate linear combination of Lorentz scalar and vector non-Coulombic potentials, with the scalar part dominating, can be chosen to give exact analytic Dirac wave functions.
hep-ph/0703115
Davor Horvatic
D. Horvatic, D. Blaschke, D. Klabucar, A. E. Radzhabov
Pseudoscalar Meson Nonet at Zero and Finite Temperature
14 pages, 11 figures, accepted for publication in Physics of Particles and Nuclei Letters, based on invited lectures at "Dense Matter In Heavy Ion Collisions and Astrophysics", 21.08-01.09 2006, Dubna, Russia
Phys.Part.Nucl.39:1033-1039,2008
10.1134/S1063779608070095
ZTF-06-09-1
hep-ph nucl-th
null
Theoretical understanding of experimental results from relativistic heavy-ion collisions requires a microscopic approach to the behavior of QCD n-point functions at finite temperatures, as given by the hierarchy of Dyson-Schwinger equations, properly generalized within the Matsubara formalism. The convergence of sums over Matsubara modes is studied. The technical complexity of finite-temperature calculations mandates modeling. We present a model where the QCD interaction in the infrared, nonperturbative domain, is modeled by a separable form. Results for the mass spectrum of light quark flavors (u, d, s) and for the pseudoscalar bound-state amplitudes at finite temperature are presented.
[ { "created": "Sun, 11 Mar 2007 14:39:00 GMT", "version": "v1" } ]
2008-12-18
[ [ "Horvatic", "D.", "" ], [ "Blaschke", "D.", "" ], [ "Klabucar", "D.", "" ], [ "Radzhabov", "A. E.", "" ] ]
Theoretical understanding of experimental results from relativistic heavy-ion collisions requires a microscopic approach to the behavior of QCD n-point functions at finite temperatures, as given by the hierarchy of Dyson-Schwinger equations, properly generalized within the Matsubara formalism. The convergence of sums over Matsubara modes is studied. The technical complexity of finite-temperature calculations mandates modeling. We present a model where the QCD interaction in the infrared, nonperturbative domain, is modeled by a separable form. Results for the mass spectrum of light quark flavors (u, d, s) and for the pseudoscalar bound-state amplitudes at finite temperature are presented.
2104.13954
Maxim V. Polyakov
Jambul Gegelia, Maxim V. Polyakov
A bound on the nucleon Druck-term from chiral EFT in curved space-time and mechanical stability conditions
minor corrections, version accepted for publication
null
10.1016/j.physletb.2021.136572
null
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Using dispersive representations of the nucleon gravitational form factors, the results for their absorptive parts from chiral effective field theory in curved space-time, and the mechanical stability conditions, we obtain a model independent inequality for the value of the gravitational $D(t)$ form factor at zero momentum transfer (Druck-term). In particular, the obtained inequality leads to a conservative bound on the Druck-term in the chiral limit $D \leq -0.95(9)$. This bound implies the restriction on the low-energy constant $c_8$ of the effective chiral action for nucleons and pions in the presence of an external gravitational field, $c_8\leq -1.1(1)$ GeV$^{-1}$. For the physical pion mass we obtain a model independent bound $D\leq -0.20(2)$.
[ { "created": "Wed, 28 Apr 2021 18:23:30 GMT", "version": "v1" }, { "created": "Tue, 3 Aug 2021 15:27:26 GMT", "version": "v2" } ]
2021-08-11
[ [ "Gegelia", "Jambul", "" ], [ "Polyakov", "Maxim V.", "" ] ]
Using dispersive representations of the nucleon gravitational form factors, the results for their absorptive parts from chiral effective field theory in curved space-time, and the mechanical stability conditions, we obtain a model independent inequality for the value of the gravitational $D(t)$ form factor at zero momentum transfer (Druck-term). In particular, the obtained inequality leads to a conservative bound on the Druck-term in the chiral limit $D \leq -0.95(9)$. This bound implies the restriction on the low-energy constant $c_8$ of the effective chiral action for nucleons and pions in the presence of an external gravitational field, $c_8\leq -1.1(1)$ GeV$^{-1}$. For the physical pion mass we obtain a model independent bound $D\leq -0.20(2)$.
1505.02624
David d'Enterria
David d'Enterria and and Redamy P\'erez-Ramos
$\alpha_s$ determination at NNLO$^\star$+NNLL accuracy from the energy evolution of jet fragmentation functions at low $z$
4 pages, 3 figures. Proceedings Rencontres Moriond "QCD and high energy interactions", March 2015, La Thuile. Typo corrected
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The QCD coupling $\alpha_s$ is extracted from the energy evolution of the first two moments (multiplicity and mean) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. Comparisons of the experimental $e^+e^-$ and deep-inelastic $e^\pm$p jet data to our NNLO$^*$+NNLL predictions, allow us to obtain $\alpha_s(m_{_{\rm Z}})$ = 0.1205$\pm$0.0010$^{+0.0022}_{-0.0000}$, in excellent agreement with the current world average determined using other methods at the same level of accuracy.
[ { "created": "Mon, 11 May 2015 14:00:25 GMT", "version": "v1" }, { "created": "Tue, 19 May 2015 14:27:57 GMT", "version": "v2" } ]
2015-05-20
[ [ "d'Enterria", "David", "" ], [ "Pérez-Ramos", "and Redamy", "" ] ]
The QCD coupling $\alpha_s$ is extracted from the energy evolution of the first two moments (multiplicity and mean) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. Comparisons of the experimental $e^+e^-$ and deep-inelastic $e^\pm$p jet data to our NNLO$^*$+NNLL predictions, allow us to obtain $\alpha_s(m_{_{\rm Z}})$ = 0.1205$\pm$0.0010$^{+0.0022}_{-0.0000}$, in excellent agreement with the current world average determined using other methods at the same level of accuracy.
1510.07902
Baoyi Chen
Baoyi Chen
Charmonium Production with QGP and Hadron Gas Effects at SPS and FAIR
6 pages, 7 figures
Phys. Rev. C 93, 044917 (2016)
10.1103/PhysRevC.93.044917
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of charmonium in heavy-ion collisions is investigated based on Boltzmann-type transport model for charmonium evolution and langevin equation for charm quark evolution. Charmonium suppression and regeneration in both quark-gluon plasma (QGP) and hadron phase are considered. Charm quarks are far from thermalization, and regeneration of charmonium in QGP and hadron gas is neglectable at SPS and FAIR. At peripheral collisions, charmonium suppression with hadron gas explains the experimental data well. But at central collisions, additional suppression from deconfined matter (QGP) is necessary for the data. This means there should be QGP produced at central collisions, and no QGP produced at peripheral collisions at SPS energy. Predictions are also made at FAIR $\sqrt{s_{NN}}=7.7$ GeV Au+Au collisions.
[ { "created": "Tue, 27 Oct 2015 13:50:11 GMT", "version": "v1" }, { "created": "Mon, 2 Nov 2015 00:53:19 GMT", "version": "v2" } ]
2016-05-04
[ [ "Chen", "Baoyi", "" ] ]
The production of charmonium in heavy-ion collisions is investigated based on Boltzmann-type transport model for charmonium evolution and langevin equation for charm quark evolution. Charmonium suppression and regeneration in both quark-gluon plasma (QGP) and hadron phase are considered. Charm quarks are far from thermalization, and regeneration of charmonium in QGP and hadron gas is neglectable at SPS and FAIR. At peripheral collisions, charmonium suppression with hadron gas explains the experimental data well. But at central collisions, additional suppression from deconfined matter (QGP) is necessary for the data. This means there should be QGP produced at central collisions, and no QGP produced at peripheral collisions at SPS energy. Predictions are also made at FAIR $\sqrt{s_{NN}}=7.7$ GeV Au+Au collisions.
2112.07680
Anjie Gao
Markus A. Ebert, Anjie Gao, and Iain W. Stewart
Factorization for Azimuthal Asymmetries in SIDIS at Next-to-Leading Power
118 pages, 1 figure; Update fixing typos and with complex C^(1) [JHEP erratum version]
null
10.1007/JHEP06(2022)007
MPP--2021--203, MIT--CTP--5373
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Differential measurements of the semi-inclusive deep inelastic scattering (SIDIS) process with polarized beams provide important information on the three-dimensional structure of hadrons. Among the various observables are azimuthal asymmetries that start at subleading power, and which give access to novel transverse momentum dependent distributions (TMDs). Theoretical predictions for these distributions are currently based on the parton model rather than a rigorous factorization based analysis. Working under the assumption that leading power Glauber interactions do not spoil factorization at this order, we use the Soft Collinear Effective Theory to derive a complete factorization formula for power suppressed hard scattering effects in SIDIS. This yields generalized definitions of the TMDs that depend on two longitudinal momentum fractions (one of them only relevant beyond tree level), and a complete proof that only the same leading power soft function appears and can be absorbed into the TMD distributions at this order. We also show that perturbative corrections can be accounted for with only one new hard coefficient. Factorization formulae are given for all spin dependent structure functions which start at next-to-leading power. Prospects for improved subleading power predictions that include resummation are discussed.
[ { "created": "Tue, 14 Dec 2021 19:00:01 GMT", "version": "v1" }, { "created": "Fri, 24 Jun 2022 03:40:05 GMT", "version": "v2" }, { "created": "Tue, 20 Jun 2023 15:54:13 GMT", "version": "v3" } ]
2023-06-21
[ [ "Ebert", "Markus A.", "" ], [ "Gao", "Anjie", "" ], [ "Stewart", "Iain W.", "" ] ]
Differential measurements of the semi-inclusive deep inelastic scattering (SIDIS) process with polarized beams provide important information on the three-dimensional structure of hadrons. Among the various observables are azimuthal asymmetries that start at subleading power, and which give access to novel transverse momentum dependent distributions (TMDs). Theoretical predictions for these distributions are currently based on the parton model rather than a rigorous factorization based analysis. Working under the assumption that leading power Glauber interactions do not spoil factorization at this order, we use the Soft Collinear Effective Theory to derive a complete factorization formula for power suppressed hard scattering effects in SIDIS. This yields generalized definitions of the TMDs that depend on two longitudinal momentum fractions (one of them only relevant beyond tree level), and a complete proof that only the same leading power soft function appears and can be absorbed into the TMD distributions at this order. We also show that perturbative corrections can be accounted for with only one new hard coefficient. Factorization formulae are given for all spin dependent structure functions which start at next-to-leading power. Prospects for improved subleading power predictions that include resummation are discussed.
hep-ph/0412177
Claude Semay
F. Brau, C. Semay
A mass formula for light mesons from a potential model
5 figures
J.Phys.G28:2771-2781,2002
10.1088/0954-3899/28/11/303
null
hep-ph
null
The quark dynamics inside light mesons, except pseudoscalar ones, can be quite well described by a spinless Salpeter equation supplemented by a Cornell interaction (possibly partly vector, partly scalar). A mass formula for these mesons can then be obtained by computing analytical approximations of the eigenvalues of the equation. We show that such a formula can be derived by combining the results of two methods: the dominantly orbital state description and the Bohr-Sommerfeld quantization approach. The predictions of the mass formula are compared with accurate solutions of the spinless Salpeter equation computed with a Lagrange-mesh calculation method.
[ { "created": "Tue, 14 Dec 2004 13:36:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Brau", "F.", "" ], [ "Semay", "C.", "" ] ]
The quark dynamics inside light mesons, except pseudoscalar ones, can be quite well described by a spinless Salpeter equation supplemented by a Cornell interaction (possibly partly vector, partly scalar). A mass formula for these mesons can then be obtained by computing analytical approximations of the eigenvalues of the equation. We show that such a formula can be derived by combining the results of two methods: the dominantly orbital state description and the Bohr-Sommerfeld quantization approach. The predictions of the mass formula are compared with accurate solutions of the spinless Salpeter equation computed with a Lagrange-mesh calculation method.
2111.02417
Tobias Isken
Hakan Akdag, Tobias Isken, Bastian Kubis
Patterns of $C$- and $CP$-violation in hadronic $\eta$ and $\eta'$ three-body decays
43 pages, 9 figures, 5 tables; v2: discussion extended, version published in JHEP; v3: incorporates an erratum that fixes the phases of the C-violating norms by hermiticity and time reversal
JHEP 02 (2022) 137; JHEP 12 (2022) 156 (erratum)
10.1007/JHEP02(2022)137
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct hadronic amplitudes for the three-body decays $\eta^{(\prime)}\to\pi^+\pi^-\pi^0$ and $\eta'\to\eta\pi^+\pi^-$ in a non-perturbative fashion, allowing for $C$- and $CP$-violating asymmetries in the $\pi^+\pi^-$ distributions. These amplitudes are consistent with the constraints of analyticity and unitarity. We find that the currently most accurate Dalitz-plot distributions taken by the KLOE-2 and BESIII collaborations confine the patterns of these asymmetries to a relative per mille level. Our dispersive representation allows us to extract the individual coupling strengths of the $C$- and $CP$-violating contributions arising from effective isoscalar and isotensor operators in $\eta^{(\prime)}\to\pi^+\pi^-\pi^0$ and an effective isovector operator in $\eta'\to\eta\pi^+\pi^-$, while the strongly different sensitivities to these operators can be understood from chiral power counting arguments.
[ { "created": "Wed, 3 Nov 2021 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 22 Feb 2022 17:32:06 GMT", "version": "v2" }, { "created": "Fri, 27 Jan 2023 15:10:33 GMT", "version": "v3" } ]
2023-01-30
[ [ "Akdag", "Hakan", "" ], [ "Isken", "Tobias", "" ], [ "Kubis", "Bastian", "" ] ]
We construct hadronic amplitudes for the three-body decays $\eta^{(\prime)}\to\pi^+\pi^-\pi^0$ and $\eta'\to\eta\pi^+\pi^-$ in a non-perturbative fashion, allowing for $C$- and $CP$-violating asymmetries in the $\pi^+\pi^-$ distributions. These amplitudes are consistent with the constraints of analyticity and unitarity. We find that the currently most accurate Dalitz-plot distributions taken by the KLOE-2 and BESIII collaborations confine the patterns of these asymmetries to a relative per mille level. Our dispersive representation allows us to extract the individual coupling strengths of the $C$- and $CP$-violating contributions arising from effective isoscalar and isotensor operators in $\eta^{(\prime)}\to\pi^+\pi^-\pi^0$ and an effective isovector operator in $\eta'\to\eta\pi^+\pi^-$, while the strongly different sensitivities to these operators can be understood from chiral power counting arguments.
hep-ph/0012083
Antonio Lopez Maroto
A.L. Maroto and J.R. Pelaez
Gravitino production during preheating and the equivalence theorem
4 pages, 1 figure. Contribution to the Proceedings of the EuroConference on Frontiers in Particle Astrophysics and Cosmology, San Feliu de Guixols, Spain, 30 September - 5 October 2000
Nucl.Phys.Proc.Suppl.95:47-50,2001
10.1016/S0920-5632(01)01052-0
null
hep-ph
null
We review our results on the calculation of helicity 1/2 gravitino production during preheating. The method we present is based on the equivalence between goldstinos and longitudinal gravitinos at high energies. The problem is thus reduced to the standard (Majorana) fermion production after inflation. Comparison between helicity 3/2 and 1/2 production and with the results obtained in the unitary gauge is also presented.
[ { "created": "Thu, 7 Dec 2000 14:37:27 GMT", "version": "v1" } ]
2008-11-26
[ [ "Maroto", "A. L.", "" ], [ "Pelaez", "J. R.", "" ] ]
We review our results on the calculation of helicity 1/2 gravitino production during preheating. The method we present is based on the equivalence between goldstinos and longitudinal gravitinos at high energies. The problem is thus reduced to the standard (Majorana) fermion production after inflation. Comparison between helicity 3/2 and 1/2 production and with the results obtained in the unitary gauge is also presented.
hep-ph/0007195
Liubomir Borissov
L. Borissov, J. Conrad, M. Shaevitz
Searching for the Lightest Neutralino at Fixed Target Experiments
4 pages, 6 figs, phenomenological study
null
null
null
hep-ph
null
Most ongoing supersymmetry searches have concentrated on the high-energy frontier. High-intensity fixed target beamlines, however, offer an opportunity to search for supersymmetric particles with long lifetimes and low cross-sections in regions complementary to the ones accessible to collider experiments. In this paper, we consider R-parity violating supersymmetry searches for the lightest neutralino and use the NuTeV experiment as an example for the experimental sensitivity which can be achieved.
[ { "created": "Tue, 18 Jul 2000 21:29:07 GMT", "version": "v1" }, { "created": "Wed, 19 Jul 2000 16:23:06 GMT", "version": "v2" }, { "created": "Mon, 28 Aug 2000 20:22:41 GMT", "version": "v3" }, { "created": "Thu, 7 Sep 2000 06:34:15 GMT", "version": "v4" }, { "created": "Fri, 10 Nov 2000 17:17:15 GMT", "version": "v5" } ]
2009-09-25
[ [ "Borissov", "L.", "" ], [ "Conrad", "J.", "" ], [ "Shaevitz", "M.", "" ] ]
Most ongoing supersymmetry searches have concentrated on the high-energy frontier. High-intensity fixed target beamlines, however, offer an opportunity to search for supersymmetric particles with long lifetimes and low cross-sections in regions complementary to the ones accessible to collider experiments. In this paper, we consider R-parity violating supersymmetry searches for the lightest neutralino and use the NuTeV experiment as an example for the experimental sensitivity which can be achieved.
hep-ph/9610308
Claus Grupen
Claus Grupen (Siegen University)
Multiparticle Aspects of e+e- Interactions at an Energy of 133 GeV at LEP
12 pages, 11 figures, invited talk given at "XXVI International Symposium on Multiparticle Dynamics" held in Faro, Portugal, September 1996
null
null
null
hep-ph
null
Electron-positron annihilations at an average center-of-mass energy of 133 GeV from the four LEP-experiments are presented. This includes in particular the total cross-section and multiplicities, thrust, rapidity and transverse momentum distributions as well as inclusive particle spectra.
[ { "created": "Thu, 10 Oct 1996 08:58:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grupen", "Claus", "", "Siegen University" ] ]
Electron-positron annihilations at an average center-of-mass energy of 133 GeV from the four LEP-experiments are presented. This includes in particular the total cross-section and multiplicities, thrust, rapidity and transverse momentum distributions as well as inclusive particle spectra.
1905.08402
Keming Shen
Keming Shen, Gergely G\'abor Barnaf\"oldi and Tam\'as S\'andor Bir\'o
Hadron Spectra Parameters within the Non-Extensive Approach
8 pages, 3 figures
Universe 2019, 5(5), 122
10.3390/universe5050122
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate how the non-extensive approach works in high-energy physics. Transverse momentum ($p_T$) spectra of several hadrons are fitted by various non-extensive momentum distributions and by the Boltzmann--Gibbs statistics.~It is shown that some non-extensive distributions can be transferred one into another.~We find explicit hadron mass and center-of-mass energy {scaling both in the temperature and in the non-extensive parameter, $q$,} in proton--proton and heavy-ion collisions. We find that the temperature depends linearly, but the Tsallis $q$ follows a logarithmic dependence on the collision energy in proton--proton collisions. In the nucleus--nucleus collisions, on~the other hand, $T$ and $q$ correlate linearly, as was predicted in our previous work.
[ { "created": "Tue, 21 May 2019 01:50:58 GMT", "version": "v1" } ]
2019-05-23
[ [ "Shen", "Keming", "" ], [ "Barnaföldi", "Gergely Gábor", "" ], [ "Biró", "Tamás Sándor", "" ] ]
We investigate how the non-extensive approach works in high-energy physics. Transverse momentum ($p_T$) spectra of several hadrons are fitted by various non-extensive momentum distributions and by the Boltzmann--Gibbs statistics.~It is shown that some non-extensive distributions can be transferred one into another.~We find explicit hadron mass and center-of-mass energy {scaling both in the temperature and in the non-extensive parameter, $q$,} in proton--proton and heavy-ion collisions. We find that the temperature depends linearly, but the Tsallis $q$ follows a logarithmic dependence on the collision energy in proton--proton collisions. In the nucleus--nucleus collisions, on~the other hand, $T$ and $q$ correlate linearly, as was predicted in our previous work.
hep-ph/9808327
Florian Scheck
Gabriela Barenboim and Florian Scheck (Mainz University)
Only Three
10 pages, 2 Postscript figures (eps)
Phys.Lett. B440 (1998) 332
10.1016/S0370-2693(98)01115-0
MZ-TH/98-29
hep-ph
null
It is shown that it is possible to account for all experimental indications for neutrino oscillations with just three flavours. In particular we suggest that the atmospheric neutrino anomaly and the LSND result can be explained by the same mass difference and mixing. Possible implications and future tests of the resulting mass and mixing pattern are given.
[ { "created": "Fri, 14 Aug 1998 09:22:51 GMT", "version": "v1" } ]
2009-10-31
[ [ "Barenboim", "Gabriela", "", "Mainz University" ], [ "Scheck", "Florian", "", "Mainz University" ] ]
It is shown that it is possible to account for all experimental indications for neutrino oscillations with just three flavours. In particular we suggest that the atmospheric neutrino anomaly and the LSND result can be explained by the same mass difference and mixing. Possible implications and future tests of the resulting mass and mixing pattern are given.
2404.16690
Yukari Yamauchi
Vincenzo Cirigliano, Srimoyee Sen, Yukari Yamauchi
Neutrino many-body flavor evolution: the full Hamiltonian
21 pages, 16 figures
null
null
INT-PUB-24-015
hep-ph nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study neutrino flavor evolution in the quantum many-body approach using the full neutrino-neutrino Hamiltonian, including the usually neglected terms that mediate non-forward scattering processes. Working in the occupation number representation with plane waves as single-particle states, we explore the time evolution of simple initial states with up to $N=10$ neutrinos. We discuss the time evolution of the Loschmidt echo, one body flavor and kinetic observables, and the one-body entanglement entropy. For the small systems considered, we observe `thermalization' of both flavor and momentum degrees of freedom on comparable time scales, with results converging towards expectation values computed within a microcanonical ensemble. We also observe that the inclusion of non-forward processes generates a faster flavor evolution compared to the one induced by the truncated (forward) Hamiltonian.
[ { "created": "Thu, 25 Apr 2024 15:50:16 GMT", "version": "v1" } ]
2024-04-26
[ [ "Cirigliano", "Vincenzo", "" ], [ "Sen", "Srimoyee", "" ], [ "Yamauchi", "Yukari", "" ] ]
We study neutrino flavor evolution in the quantum many-body approach using the full neutrino-neutrino Hamiltonian, including the usually neglected terms that mediate non-forward scattering processes. Working in the occupation number representation with plane waves as single-particle states, we explore the time evolution of simple initial states with up to $N=10$ neutrinos. We discuss the time evolution of the Loschmidt echo, one body flavor and kinetic observables, and the one-body entanglement entropy. For the small systems considered, we observe `thermalization' of both flavor and momentum degrees of freedom on comparable time scales, with results converging towards expectation values computed within a microcanonical ensemble. We also observe that the inclusion of non-forward processes generates a faster flavor evolution compared to the one induced by the truncated (forward) Hamiltonian.
2201.01791
Yizhuang Liu
Yizhuang Liu, Maciej A. Nowak, Ismail Zahed
Hyperons and $\Theta_s^+$ in Holographic QCD
12 pages, 0 figures
null
10.1103/PhysRevD.105.114021
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the holographic description of strange baryons in the context of the Sakai-Sugimoto construction, by considering the strange quark mass as heavy. Hyperons are described by a massive $(K,K^*)$ multiplet, bound to a light-flavor instanton in bulk, much in the spirit of the Callan-Klebanov construction. The modular Hamiltonian maps onto the Landau problem, a charged particle in a 2-dimensional external magnetic field, induced by the bulk Chern-Simons interaction, plus spin-orbit coupling. The ensuing holographic hyperon spectrum compares fairly with the empirical one. The holographic strange pentaquark baryon $\Theta^+_s$ is shown to be unbound.
[ { "created": "Wed, 5 Jan 2022 19:12:44 GMT", "version": "v1" } ]
2022-06-29
[ [ "Liu", "Yizhuang", "" ], [ "Nowak", "Maciej A.", "" ], [ "Zahed", "Ismail", "" ] ]
We revisit the holographic description of strange baryons in the context of the Sakai-Sugimoto construction, by considering the strange quark mass as heavy. Hyperons are described by a massive $(K,K^*)$ multiplet, bound to a light-flavor instanton in bulk, much in the spirit of the Callan-Klebanov construction. The modular Hamiltonian maps onto the Landau problem, a charged particle in a 2-dimensional external magnetic field, induced by the bulk Chern-Simons interaction, plus spin-orbit coupling. The ensuing holographic hyperon spectrum compares fairly with the empirical one. The holographic strange pentaquark baryon $\Theta^+_s$ is shown to be unbound.
2401.05666
Pablo Roig
Pere Masjuan and Pablo Roig
Data-driven approximations to the Hadronic Light-by-Light scattering contribution to the muon (g-2)
5 pages + references. Accepted for publication in the proceedings of the HADRON 2023 Conference, Genova, Italy, 5-9 June 2023
null
null
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
We review recent progress on the numerical determination of the Hadronic Light-by-Light contribution to the anomalous magnetic moment of the muon. We advocate for a slight increase of the White Paper number for its Standard Model prediction, to $(102\pm17)\times10^{-11}$, accounting for a revised contribution from axial-vector mesons and short-distance constraints. This $\sim10\%$ larger result seems to be supported by the most recent lattice QCD evaluations.
[ { "created": "Thu, 11 Jan 2024 04:57:08 GMT", "version": "v1" } ]
2024-01-12
[ [ "Masjuan", "Pere", "" ], [ "Roig", "Pablo", "" ] ]
We review recent progress on the numerical determination of the Hadronic Light-by-Light contribution to the anomalous magnetic moment of the muon. We advocate for a slight increase of the White Paper number for its Standard Model prediction, to $(102\pm17)\times10^{-11}$, accounting for a revised contribution from axial-vector mesons and short-distance constraints. This $\sim10\%$ larger result seems to be supported by the most recent lattice QCD evaluations.
1603.04126
Guilherme Gomes
G. Balieiro Gomes, M. M. Guzzo, P. C. de Holanda, R. L. N. Oliveira
Parameter Limits for Neutrino Oscillation with Decoherence in KamLAND
null
Phys. Rev. D 95, 113005 (2017)
10.1103/PhysRevD.95.113005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of quantum open systems we analyze data from KamLAND by using a model that considers neutrino oscillation in a three-family approximation with the inclusion of the decoherence effect. Using a $\chi^2$ test we find new limits for the decoherence parameter which we call $\gamma$, considering the most recent data by KamLAND. Assuming an energy dependence of the type $ \gamma = \gamma_0 \left( E/E_0 \right) ^n$, in 95 \% C.L. the limits found are $3.7 \times 10^{-24} GeV$ for $ n=-1$, $6.8 \times 10^{-22} GeV$ for $ n=0$, and $1.5 \times 10^{-19} GeV$ for $ n=1 $ on the energy dependence.
[ { "created": "Mon, 14 Mar 2016 03:46:47 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2016 18:47:48 GMT", "version": "v2" }, { "created": "Sat, 1 Apr 2017 18:25:29 GMT", "version": "v3" } ]
2017-06-28
[ [ "Gomes", "G. Balieiro", "" ], [ "Guzzo", "M. M.", "" ], [ "de Holanda", "P. C.", "" ], [ "Oliveira", "R. L. N.", "" ] ]
In the framework of quantum open systems we analyze data from KamLAND by using a model that considers neutrino oscillation in a three-family approximation with the inclusion of the decoherence effect. Using a $\chi^2$ test we find new limits for the decoherence parameter which we call $\gamma$, considering the most recent data by KamLAND. Assuming an energy dependence of the type $ \gamma = \gamma_0 \left( E/E_0 \right) ^n$, in 95 \% C.L. the limits found are $3.7 \times 10^{-24} GeV$ for $ n=-1$, $6.8 \times 10^{-22} GeV$ for $ n=0$, and $1.5 \times 10^{-19} GeV$ for $ n=1 $ on the energy dependence.
1508.06083
C. J. A. P. Martins
S. M. Jo\~ao, C. J. A. P. Martins, I. S. A. B. Mota and P. M. T. Vianez
On the Stability of Fundamental Couplings in the Galaxy
7 pages, 1 figure
Physics Letters B 749 (2015) 389-392
10.1016/j.physletb.2015.08.018
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Astrophysical tests of the stability of Nature's fundamental couplings are a key probe of the standard paradigms in fundamental physics and cosmology. In this report we discuss updated constraints on the stability of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu=m_p/m_e$ within the Galaxy. We revisit and improve upon the analysis by Truppe {\it et al.} by allowing for the possibility of simultaneous variations of both couplings and also by combining them with the recent measurements by Levshakov {\it et al.} By considering representative unification scenarios we find no evidence for variations of $\alpha$ at the 0.4 ppm level, and of $\mu$ at the 0.6 ppm level; if one uses the Levshakov bound on $\mu$ as a prior, the$\alpha$ bound is improved to 0.1 ppm. We also highlight how these measurements can constrain (and discriminate among) several fundamental physics paradigms.
[ { "created": "Tue, 25 Aug 2015 09:25:58 GMT", "version": "v1" } ]
2015-08-26
[ [ "João", "S. M.", "" ], [ "Martins", "C. J. A. P.", "" ], [ "Mota", "I. S. A. B.", "" ], [ "Vianez", "P. M. T.", "" ] ]
Astrophysical tests of the stability of Nature's fundamental couplings are a key probe of the standard paradigms in fundamental physics and cosmology. In this report we discuss updated constraints on the stability of the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu=m_p/m_e$ within the Galaxy. We revisit and improve upon the analysis by Truppe {\it et al.} by allowing for the possibility of simultaneous variations of both couplings and also by combining them with the recent measurements by Levshakov {\it et al.} By considering representative unification scenarios we find no evidence for variations of $\alpha$ at the 0.4 ppm level, and of $\mu$ at the 0.6 ppm level; if one uses the Levshakov bound on $\mu$ as a prior, the$\alpha$ bound is improved to 0.1 ppm. We also highlight how these measurements can constrain (and discriminate among) several fundamental physics paradigms.
1902.10411
Javier Fuentes-Mart\'in
Ling-Yun Dai, Javier Fuentes-Martin, Jorge Portoles
Scalar-involved three-point Green functions and their phenomenology
30 pages, 5 figures. v2: Typos in Eqs. (B.4) and (B.6) of the appendices in the published version are corrected
Phys. Rev. D 99, 114015 (2019)
10.1103/PhysRevD.99.114015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyse within the framework of resonance chiral theory the $\langle SA_\mu A_\nu \rangle$ and $\langle SV_\mu V_\nu \rangle$ three-point Green functions, where $S$, $A_{\mu} $ and $V_{\mu}$ are short for scalar, axial-vector and vector $SU(3)$ hadronic currents. We construct the necessary Lagrangian such that the Green functions fulfill the asymptotic constraints, at large momenta, imposed by QCD at leading order. We study the implications of our results on the spectrum of scalars in the large-$N_C$ limit, and analyse their decays.
[ { "created": "Wed, 27 Feb 2019 09:40:54 GMT", "version": "v1" }, { "created": "Sun, 14 Mar 2021 19:27:40 GMT", "version": "v2" } ]
2021-03-16
[ [ "Dai", "Ling-Yun", "" ], [ "Fuentes-Martin", "Javier", "" ], [ "Portoles", "Jorge", "" ] ]
We analyse within the framework of resonance chiral theory the $\langle SA_\mu A_\nu \rangle$ and $\langle SV_\mu V_\nu \rangle$ three-point Green functions, where $S$, $A_{\mu} $ and $V_{\mu}$ are short for scalar, axial-vector and vector $SU(3)$ hadronic currents. We construct the necessary Lagrangian such that the Green functions fulfill the asymptotic constraints, at large momenta, imposed by QCD at leading order. We study the implications of our results on the spectrum of scalars in the large-$N_C$ limit, and analyse their decays.
hep-ph/9608378
Brian Harris
B. W. Harris and J. F. Owens (Florida State University)
Photoproduction of jets at NLO
To appear in proceedings of the 1996 Meeting of the American Physical Society, Division of Particles and Fields (DPF 96), Minneapolis, Minnesota, 10-15 Aug 1996. 3 pages, Latex using sprocl.sty (included)
null
null
null
hep-ph
null
A new next-to-leading order Monte Carlo program for the calculation of fully differential jet cross sections in photoproduction is described. The contributions from both resolved and direct components are included. A comparison between the theoretical predictions and ZEUS data is presented.
[ { "created": "Tue, 20 Aug 1996 17:41:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Harris", "B. W.", "", "Florida State University" ], [ "Owens", "J. F.", "", "Florida State University" ] ]
A new next-to-leading order Monte Carlo program for the calculation of fully differential jet cross sections in photoproduction is described. The contributions from both resolved and direct components are included. A comparison between the theoretical predictions and ZEUS data is presented.
1401.5118
Zhenjun Xiao
Shan Cheng, Ying-Ying Fan and Zhen-Jun Xiao
The NLO twist-3 contribution to the pion electromagnetic form factors in $k_{T}$ factorization
26 pages, 10 ps figures and 2 Tables, minor corrections
Phys. Rev. D 89, 054015 (2014)
10.1103/PhysRevD.89.054015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, by employing the $k_{T}$ factorization theorem, we calculate firstly the next-to-leading-order (NLO) twist-3 contributions to the pion electromagnetic form factors in the $\pi\gamma^* \to \pi$ process. From the analytical and numerical calculations we find the following points: (a) For the leading order (LO) twist-2, twist-3 and the NLO twist-2 contributions, our results agree very well with those obtained in previous works; (b) We extract out two factors $F^{(1)}_{\rm T3}(x_i,t,Q^2)$ and $\ov{F}^{(1)}_{\rm T3}(x_i,t,Q^2)$, which describe directly the NLO twist-3 contributions to the pion electromagnetic form factors $F^+(Q^2)$; (c) The NLO twist-3 contribution is negative in sign and cancel partially with the NLO twist-2 part, the total NLO contribution can therefore provide a roughly $\pm 20\%$ corrections to the total LO contribution in the considered ranges of $Q^2$; and (d) The theoretical predictions for $Q^2 F^+(Q^2)$ in the low-$Q^2$ region agree well with currently available data, this agreement can be improved by the inclusion of the NLO contributions.
[ { "created": "Mon, 20 Jan 2014 23:00:50 GMT", "version": "v1" } ]
2014-03-26
[ [ "Cheng", "Shan", "" ], [ "Fan", "Ying-Ying", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper, by employing the $k_{T}$ factorization theorem, we calculate firstly the next-to-leading-order (NLO) twist-3 contributions to the pion electromagnetic form factors in the $\pi\gamma^* \to \pi$ process. From the analytical and numerical calculations we find the following points: (a) For the leading order (LO) twist-2, twist-3 and the NLO twist-2 contributions, our results agree very well with those obtained in previous works; (b) We extract out two factors $F^{(1)}_{\rm T3}(x_i,t,Q^2)$ and $\ov{F}^{(1)}_{\rm T3}(x_i,t,Q^2)$, which describe directly the NLO twist-3 contributions to the pion electromagnetic form factors $F^+(Q^2)$; (c) The NLO twist-3 contribution is negative in sign and cancel partially with the NLO twist-2 part, the total NLO contribution can therefore provide a roughly $\pm 20\%$ corrections to the total LO contribution in the considered ranges of $Q^2$; and (d) The theoretical predictions for $Q^2 F^+(Q^2)$ in the low-$Q^2$ region agree well with currently available data, this agreement can be improved by the inclusion of the NLO contributions.
1707.00866
Tommi Markkanen
Tommi Markkanen, Sami Nurmi and Arttu Rajantie
Do metric fluctuations affect the Higgs dynamics during inflation?
v1: 13 pages. v2: some improvements, additional references, accepted for publication by JCAP
null
10.1088/1475-7516/2017/12/026
KCL-PH-TH/2017-32, IMPERIAL/TP/2017/TM/02
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that the dynamics of the Higgs field during inflation is not affected by metric fluctuations if the Higgs is an energetically subdominant light spectator. For Standard Model parameters we find that couplings between Higgs and metric fluctuations are suppressed by $\mathcal{O}(10^{-7})$. They are negligible compared to both pure Higgs terms in the effective potential and the unavoidable non-minimal Higgs coupling to background scalar curvature. The question of the electroweak vacuum instability during high energy scale inflation can therefore be studied consistently using the Jordan frame action in a Friedmann--Lema\^itre--Robertson--Walker metric, where the Higgs-curvature coupling enters as an effective mass contribution. Similar results apply for other light spectator scalar fields during inflation.
[ { "created": "Tue, 4 Jul 2017 09:10:13 GMT", "version": "v1" }, { "created": "Mon, 27 Nov 2017 14:17:49 GMT", "version": "v2" } ]
2017-12-27
[ [ "Markkanen", "Tommi", "" ], [ "Nurmi", "Sami", "" ], [ "Rajantie", "Arttu", "" ] ]
We show that the dynamics of the Higgs field during inflation is not affected by metric fluctuations if the Higgs is an energetically subdominant light spectator. For Standard Model parameters we find that couplings between Higgs and metric fluctuations are suppressed by $\mathcal{O}(10^{-7})$. They are negligible compared to both pure Higgs terms in the effective potential and the unavoidable non-minimal Higgs coupling to background scalar curvature. The question of the electroweak vacuum instability during high energy scale inflation can therefore be studied consistently using the Jordan frame action in a Friedmann--Lema\^itre--Robertson--Walker metric, where the Higgs-curvature coupling enters as an effective mass contribution. Similar results apply for other light spectator scalar fields during inflation.
2210.07007
Lois Flower
Lois Flower, Marek Schoenherr
Photon splitting corrections to soft-photon resummation
25 pages, 10 figures
J. High Energ. Phys. 2023, 238 (2023)
10.1007/JHEP03(2023)238
IPPP/22/69, MCnet-22-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present an algorithm to add photon-splitting corrections to the Yennie-Frautschi-Suura-style soft-photon resummation available in the Sherpa Monte-Carlo event generator. Photon-splitting corrections enter at NNLO in QED and, as these effects are not incorporated in the standard QED FSR resummations, their size is larger than the pure hard photon-emission corrections at the same order. We introduce different lepton dressing strategies which incorporate further leptons and hadrons in addition to the customary photons, and discuss their sensitivity to dressing parameters such as the cone size. Finally, we quantify the effects of photon splittings into charged fermions and scalars under different such dressing strategies on $Z\to e^+e^-$ decays and find effects of up to 1% for suitably inclusive dressing strategies independent of the dressing cone size, and up to 9% if only photons are used in the dressing procedure with large dressing cones.
[ { "created": "Thu, 13 Oct 2022 13:17:42 GMT", "version": "v1" }, { "created": "Mon, 20 Mar 2023 13:44:35 GMT", "version": "v2" } ]
2023-03-31
[ [ "Flower", "Lois", "" ], [ "Schoenherr", "Marek", "" ] ]
In this paper we present an algorithm to add photon-splitting corrections to the Yennie-Frautschi-Suura-style soft-photon resummation available in the Sherpa Monte-Carlo event generator. Photon-splitting corrections enter at NNLO in QED and, as these effects are not incorporated in the standard QED FSR resummations, their size is larger than the pure hard photon-emission corrections at the same order. We introduce different lepton dressing strategies which incorporate further leptons and hadrons in addition to the customary photons, and discuss their sensitivity to dressing parameters such as the cone size. Finally, we quantify the effects of photon splittings into charged fermions and scalars under different such dressing strategies on $Z\to e^+e^-$ decays and find effects of up to 1% for suitably inclusive dressing strategies independent of the dressing cone size, and up to 9% if only photons are used in the dressing procedure with large dressing cones.
hep-ph/0605240
Dimitri Bourilkov
D Bourilkov, R C Group, M R Whalley
LHAPDF: PDF Use from the Tevatron to the LHC
8 pages, 2 figures, 2 tables; prepared for the TeV4LHC workshop; v2 - reference added
null
null
null
hep-ph
null
Parton Density Functions (PDFs) and their uncertainties are extremely important topics for both the Tevatron and the LHC. Experiments at the Tevatron can enhance this knowledge not only by constraining the PDF fits, but also by developing and refining the available PDF tools through feed-back from the experiments that are currently analyzing the highest energy hadron collider data available. It is important that the community has standardized tools and methods at its disposal. In this note we summarize briefly the most recent developments of the The Les Houches Accord PDF (LHAPDF), which is the modern replacement for PDFLIB. We also outline and compare the methods of quantifying the impact of PDF uncertainties on physical observables. The PDF weighting method for propagating errors from PDFs to event generator observables is outlined in detail, and example code for using this method with PYTHIA is also included.
[ { "created": "Mon, 22 May 2006 20:03:21 GMT", "version": "v1" }, { "created": "Fri, 26 May 2006 18:49:09 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bourilkov", "D", "" ], [ "Group", "R C", "" ], [ "Whalley", "M R", "" ] ]
Parton Density Functions (PDFs) and their uncertainties are extremely important topics for both the Tevatron and the LHC. Experiments at the Tevatron can enhance this knowledge not only by constraining the PDF fits, but also by developing and refining the available PDF tools through feed-back from the experiments that are currently analyzing the highest energy hadron collider data available. It is important that the community has standardized tools and methods at its disposal. In this note we summarize briefly the most recent developments of the The Les Houches Accord PDF (LHAPDF), which is the modern replacement for PDFLIB. We also outline and compare the methods of quantifying the impact of PDF uncertainties on physical observables. The PDF weighting method for propagating errors from PDFs to event generator observables is outlined in detail, and example code for using this method with PYTHIA is also included.
hep-ph/0609182
Sandhya Choubey
Sandhya Choubey
What we can learn from atmospheric neutrinos
7 pages, to appear in proceedings of Neutrino 2006 Conference, Santa Fe, New Mexico, June 13-19, 2006
null
null
null
hep-ph hep-ex
null
Physics potential of future measurements of atmospheric neutrinos is explored. Observation of $\Delta m^2_{21}$ driven sub-dominant effects and $\theta_{13}$ driven large matter effects in atmospheric neutrinos can be used to study the deviation of $\theta_{23}$ from maximality and its octant. Neutrino mass hierarchy can be determined extremely well due to the large matter effects. New physics can be constrained both in standard atmospheric neutrino experiments as well as in future neutrino telescopes.
[ { "created": "Tue, 19 Sep 2006 03:54:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Choubey", "Sandhya", "" ] ]
Physics potential of future measurements of atmospheric neutrinos is explored. Observation of $\Delta m^2_{21}$ driven sub-dominant effects and $\theta_{13}$ driven large matter effects in atmospheric neutrinos can be used to study the deviation of $\theta_{23}$ from maximality and its octant. Neutrino mass hierarchy can be determined extremely well due to the large matter effects. New physics can be constrained both in standard atmospheric neutrino experiments as well as in future neutrino telescopes.
hep-ph/0608158
Fulvio Piccinini
V. Del Duca, G. Kl\"amke, M.L. Mangano, M. Moretti, F. Piccinini, R. Pittau, A.D. Polosa and D. Zeppenfeld
Monte Carlo studies of the jet activity in Higgs + 2 jet events
12 pages, 10 figures. Version to appear on JHEP. Figs. 5-8 replaced with colour versions
JHEP0610:016,2006
10.1088/1126-6708/2006/10/016
FNT/T 2006/07, DFTT 14/2006, KA-TP-06-2006
hep-ph
null
Tree-level studies have shown in the past that kinematical correlations between the two jets in Higgs+2-jet events are direct probes of the Higgs couplings, e.g. of their CP nature. In this paper we explore the impact of higher-order corrections on the azimuthal angle correlation of the two leading jets and on the rapidity distribution of extra jets. Our study includes matrix-element and shower MC effects, for the two leading sources of Higgs plus two jet events at the CERN LHC, namely vector-boson and gluon fusion. We show that the discriminating features present in the previous leading-order matrix element studies survive.
[ { "created": "Mon, 14 Aug 2006 17:28:01 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2006 19:49:31 GMT", "version": "v2" } ]
2009-11-11
[ [ "Del Duca", "V.", "" ], [ "Klämke", "G.", "" ], [ "Mangano", "M. L.", "" ], [ "Moretti", "M.", "" ], [ "Piccinini", "F.", "" ], [ "Pittau", "R.", "" ], [ "Polosa", "A. D.", "" ], [ "Zeppenfeld", "D.", "" ] ]
Tree-level studies have shown in the past that kinematical correlations between the two jets in Higgs+2-jet events are direct probes of the Higgs couplings, e.g. of their CP nature. In this paper we explore the impact of higher-order corrections on the azimuthal angle correlation of the two leading jets and on the rapidity distribution of extra jets. Our study includes matrix-element and shower MC effects, for the two leading sources of Higgs plus two jet events at the CERN LHC, namely vector-boson and gluon fusion. We show that the discriminating features present in the previous leading-order matrix element studies survive.
hep-ph/9610299
null
S. Dawson (BNL), A. Likhoded (IITAP), G. Valencia (ISU), and O. Yushchenko (IHEP)
Probing Quartic Couplings Through Three Gauge Boson Production at an $e^+e^-$ Linear Collider
To appear in the Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics, Snowmass, CO, June 25-July 12, 1996; 4 pg, uses LATEX2e with epsfig and snow2e.cls
null
null
BNL-HET-SD-7
hep-ph
null
We explore the capability of a 500 or 1000 GeV $e^+e^-$ linear collider to measure anomalous quartic gauge boson couplings. In the framework of a non-linear effective Lagrangian with a custodial $SU)2)$ symmetry, there are only two next-to-leading order operators which contribute to quartic, but not to two- and three- gauge boson interactions. The limits on the coefficients of these operators from present and future $e^+e^-$ colliders are compared with those available from other sources.
[ { "created": "Wed, 9 Oct 1996 15:24:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dawson", "S.", "", "BNL" ], [ "Likhoded", "A.", "", "IITAP" ], [ "Valencia", "G.", "", "ISU" ], [ "Yushchenko", "O.", "", "IHEP" ] ]
We explore the capability of a 500 or 1000 GeV $e^+e^-$ linear collider to measure anomalous quartic gauge boson couplings. In the framework of a non-linear effective Lagrangian with a custodial $SU)2)$ symmetry, there are only two next-to-leading order operators which contribute to quartic, but not to two- and three- gauge boson interactions. The limits on the coefficients of these operators from present and future $e^+e^-$ colliders are compared with those available from other sources.