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hep-ph/9902349
Victor Manuel Villanueva Sandoval
J. L Lucio, M. Napsuciale, M. D. Scadron and V. M. Villanueva
The omega to rho pi transition and omega to rho 3 pi decay
12 pages, LaTeX, 3 eps figures, uses epsf.sty
null
null
IFUG HEP-9901
hep-ph
null
We evaluate the omega to rho pi transition and the omega to 3 pi decay using a Quark Level Linear Sigma Model ($QL\sigma M$). We obtain $g^{QL\sigma M}_{\omega\rho\pi}= (10.33 - 14.75) GeV^{-1}$ to be compared with other model dependent estimates averaging to $g_{\omega\rho\pi} = 16 GeV^{-1}$. We show that in the $QL\sigma M$ a contact term is generated for the $\omega \to 3 \pi$ decay. Although the contact contribution by itself is small, the interference effects turn out to be important.
[ { "created": "Mon, 15 Feb 1999 19:33:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lucio", "J. L", "" ], [ "Napsuciale", "M.", "" ], [ "Scadron", "M. D.", "" ], [ "Villanueva", "V. M.", "" ] ]
We evaluate the omega to rho pi transition and the omega to 3 pi decay using a Quark Level Linear Sigma Model ($QL\sigma M$). We obtain $g^{QL\sigma M}_{\omega\rho\pi}= (10.33 - 14.75) GeV^{-1}$ to be compared with other model dependent estimates averaging to $g_{\omega\rho\pi} = 16 GeV^{-1}$. We show that in the $QL\sigma M$ a contact term is generated for the $\omega \to 3 \pi$ decay. Although the contact contribution by itself is small, the interference effects turn out to be important.
hep-ph/0407278
Yong Zhou
Yong Zhou, Cai-Dian L\"u
Singularities of Feynman amplitude and cutting rules
null
null
null
null
hep-ph
null
The contents of this manuscript has been moved to hep-ph/0412204.
[ { "created": "Fri, 23 Jul 2004 10:02:50 GMT", "version": "v1" }, { "created": "Wed, 11 Aug 2004 14:28:18 GMT", "version": "v2" }, { "created": "Thu, 19 Aug 2004 09:08:57 GMT", "version": "v3" }, { "created": "Fri, 17 Dec 2004 02:22:30 GMT", "version": "v4" } ]
2007-05-23
[ [ "Zhou", "Yong", "" ], [ "Lü", "Cai-Dian", "" ] ]
The contents of this manuscript has been moved to hep-ph/0412204.
1404.0028
Narayan Rana
Taushif Ahmed, Maguni Mahakhud, Prakash Mathews, Narayan Rana and V. Ravindran
Two-Loop QCD Correction to massive spin-2 resonance $\rightarrow$ 3 gluons
null
null
10.1007/JHEP05(2014)107
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the ${\cal O}(\alpha_s^3)$ virtual QCD corrections to the process $h \rightarrow g+g+g$ due to interference of born and two-loop amplitudes, where $h$ is a massive spin-2 particle and $g$ is the gluon. We assume that the SM fields couple to $h$ through the SM energy momentum tensor. Our result constitutes one of the ingredients to full NNLO QCD contribution to production of a massive spin-2 particle along with a jet in the scattering process at the LHC. In particular, this massive spin-2 could be a KK mode of a ADD graviton in large extra dimensional model or a RS KK mode in warped extra dimensional model or a generic massive spin-2. In addition, it provides an opportunity to study the ultraviolet and infrared structures of QCD amplitudes involving tensorial coupling resulting from energy momentum operator. Using dimensional regularization, we find that infrared poles of this amplitude are in agreement with the proposal by Catani confirming the factorization property of QCD amplitudes with tensorial insertion.
[ { "created": "Mon, 31 Mar 2014 20:21:51 GMT", "version": "v1" } ]
2015-06-19
[ [ "Ahmed", "Taushif", "" ], [ "Mahakhud", "Maguni", "" ], [ "Mathews", "Prakash", "" ], [ "Rana", "Narayan", "" ], [ "Ravindran", "V.", "" ] ]
We present the ${\cal O}(\alpha_s^3)$ virtual QCD corrections to the process $h \rightarrow g+g+g$ due to interference of born and two-loop amplitudes, where $h$ is a massive spin-2 particle and $g$ is the gluon. We assume that the SM fields couple to $h$ through the SM energy momentum tensor. Our result constitutes one of the ingredients to full NNLO QCD contribution to production of a massive spin-2 particle along with a jet in the scattering process at the LHC. In particular, this massive spin-2 could be a KK mode of a ADD graviton in large extra dimensional model or a RS KK mode in warped extra dimensional model or a generic massive spin-2. In addition, it provides an opportunity to study the ultraviolet and infrared structures of QCD amplitudes involving tensorial coupling resulting from energy momentum operator. Using dimensional regularization, we find that infrared poles of this amplitude are in agreement with the proposal by Catani confirming the factorization property of QCD amplitudes with tensorial insertion.
1809.00131
Ian G. Moss
Ian G. Moss and Ruth Gregory
Higgs Cosmology and Dark Matter
5 pages, 4 figures. Talk presented at 2nd World Summit: Exploring the Dark Side of the Universe, June 2018, University of Antilles, Guadeloupe
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Higgs vacuum stability has important consequences for cosmology. In particular, we argue that if the Higgs vacuum is metastable, then the dark matter cannot contain a single black hole of mass less than $10^{15}{\rm g}$ in our entire past light cone. In addition to being the destroyer microscopic black holes, it may be possible that Higgs vacuum decay is a source of primordial black holes during inflation.
[ { "created": "Sat, 1 Sep 2018 08:03:51 GMT", "version": "v1" } ]
2018-09-05
[ [ "Moss", "Ian G.", "" ], [ "Gregory", "Ruth", "" ] ]
Higgs vacuum stability has important consequences for cosmology. In particular, we argue that if the Higgs vacuum is metastable, then the dark matter cannot contain a single black hole of mass less than $10^{15}{\rm g}$ in our entire past light cone. In addition to being the destroyer microscopic black holes, it may be possible that Higgs vacuum decay is a source of primordial black holes during inflation.
hep-ph/9506389
Jun Liu
J\`un L\'iu, Nimai C. Mukhopadhyay and Lisheng Zhang
Nucleon to Delta Weak Excitation Amplitudes in the Non-relativistic Quark Model
\documentstyle[aps]{revtex}, 21pages; 11 postscript figures. Accepted for publication by Phys. Rev. C
Phys.Rev.C52:1630-1647,1995
10.1103/PhysRevC.52.1630
null
hep-ph nucl-th
null
We investigate the nucleon to Delta(1232) vector and axial vector amplitudes in the non-relativistic quark model of the Isgur-Karl variety. A particular interest is to investigate the SU(6) symmetry breaking, due to color hyperfine interaction. We compare the theoretical estimates to recent experimental investigation of the Adler amplitudes by neutrino scattering.
[ { "created": "Thu, 22 Jun 1995 06:29:07 GMT", "version": "v1" } ]
2016-08-15
[ [ "Líu", "Jùn", "" ], [ "Mukhopadhyay", "Nimai C.", "" ], [ "Zhang", "Lisheng", "" ] ]
We investigate the nucleon to Delta(1232) vector and axial vector amplitudes in the non-relativistic quark model of the Isgur-Karl variety. A particular interest is to investigate the SU(6) symmetry breaking, due to color hyperfine interaction. We compare the theoretical estimates to recent experimental investigation of the Adler amplitudes by neutrino scattering.
hep-ph/9601298
Sean Fleming
James Amundson (MSU), Sean Fleming (U. Toronto), and Ivan Maksymyk (TRIUMF)
Photoproduction of J/$\psi$ in the forward region
Version to appear in Phys. Rev. Substantial changes
Phys.Rev. D56 (1997) 5844-5850
10.1103/PhysRevD.56.5844
UTTG-10-95, MADPH-95-914
hep-ph
null
We study the phenomenology of fixed-target elastic $J/\psi$ photoproduction in the NRQCD factorization formalism. Our the goal is to test an essential feature of this formalism --- the color-octet mechanism. We obtain an order-of-magnitude estimate for a certain linear combination of NRQCD color-octet matrix elements. Our estimate is consistent with other empirical determinations and with the $v$-scaling rules of NRQCD.
[ { "created": "Fri, 19 Jan 1996 06:15:54 GMT", "version": "v1" }, { "created": "Thu, 2 Oct 1997 16:23:48 GMT", "version": "v2" } ]
2009-10-28
[ [ "Amundson", "James", "", "MSU" ], [ "Fleming", "Sean", "", "U. Toronto" ], [ "Maksymyk", "Ivan", "", "TRIUMF" ] ]
We study the phenomenology of fixed-target elastic $J/\psi$ photoproduction in the NRQCD factorization formalism. Our the goal is to test an essential feature of this formalism --- the color-octet mechanism. We obtain an order-of-magnitude estimate for a certain linear combination of NRQCD color-octet matrix elements. Our estimate is consistent with other empirical determinations and with the $v$-scaling rules of NRQCD.
1012.5466
Ryosuke Sato
Masahiro Ibe, Ryosuke Sato, Tsutomu T. Yanagida, Kazuya Yonekura
Gravitino Dark Matter and Light Gluino in an R-invariant Low Scale Gauge Mediation
29 pages, 12 figures; v2 reference and explanation added
JHEP 1104:077,2011
10.1007/JHEP04(2011)077
IPMU-10-0222, UT-10-22
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the simplest class of the R-invariant gauge mediation model with the gravitino mass in the one to ten keV range. We show that the entropy production from the supersymmetry breaking sector makes the gravitino into a warm dark matter candidate. We also discuss that the gluino mass can be lighter than the wino mass even when the messenger sector satisfies the GUT relations at the GUT scale.
[ { "created": "Sat, 25 Dec 2010 12:12:47 GMT", "version": "v1" }, { "created": "Fri, 15 Apr 2011 10:11:21 GMT", "version": "v2" } ]
2015-03-17
[ [ "Ibe", "Masahiro", "" ], [ "Sato", "Ryosuke", "" ], [ "Yanagida", "Tsutomu T.", "" ], [ "Yonekura", "Kazuya", "" ] ]
We consider the simplest class of the R-invariant gauge mediation model with the gravitino mass in the one to ten keV range. We show that the entropy production from the supersymmetry breaking sector makes the gravitino into a warm dark matter candidate. We also discuss that the gluino mass can be lighter than the wino mass even when the messenger sector satisfies the GUT relations at the GUT scale.
2306.11653
Bartol Pavlovi\'c
Monojit Ghosh, Srubabati Goswami, Supriya Pan and Bartol Pavlovi\'c
Implications of the DLMA solution of $\theta_{12}$ for IceCube data using different astrophysical sources
10 pages, 6 figures, 3 tables. Version accepted for publication in Universe
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the implications of the Dark Large Mixing Angle (DLMA) solutions of $\theta_{12}$ in the context of the IceCube data. We study the consequences in the measurement of the neutrino oscillation parameters namely $\theta_{23}$ and $\delta_{\rm CP}$ in light of both Large Mixing Angle (LMA) and DLMA solutions of $\theta_{12}$. We find that it will be impossible for IceCube to determine the $\delta_{\rm CP}$ and the true nature of $\theta_{12}$ i.e., LMA or DLMA at the same time. This is because of the existence of an intrinsic degeneracy at the Hamiltonian level between these parameters. Apart from that, we also identify a new degeneracy between $\theta_{23}$ and two solutions of $\theta_{12}$ for a fixed value of $\delta_{\rm CP}$. We perform a chi-square fit using three different astrophysical sources, i.e., $\mu$ source, $\pi$ source, and $n$ source to find that both $\mu$ source and $\pi$ source are allowed within $1 \sigma$ whereas the $n$ source is excluded at $2 \sigma$. It is difficult to make any conclusion regarding the measurement of $\theta_{23}$, $\delta_{\rm CP}$ for $\mu$ source. However, The $\pi$ ($n$) source prefers higher (lower) octant of $\theta_{23}$ for both LMA and DLMA solution of $\theta_{12}$. The best-fit value of $\delta_{\rm CP}$ is around $180^\circ$ ($0^\circ/360^\circ$) for LMA (DLMA) solution of $\theta_{12}$ whereas for DLMA (LMA) solution of $\theta_{12}$, the best-fit value is around $0^\circ/360^\circ$ ($180^\circ$) for $\pi$ ($n$) source. If we assume the current best-fit values of $\theta_{23}$ and $\delta_{\rm CP}$ to be true, then the $\mu$ and $\pi$ source prefer the LMA solution of $\theta_{12}$ whereas the $n$ source prefers the DLMA solution of $\theta_{12}$.
[ { "created": "Tue, 20 Jun 2023 16:25:00 GMT", "version": "v1" }, { "created": "Wed, 23 Aug 2023 13:51:50 GMT", "version": "v2" } ]
2023-08-24
[ [ "Ghosh", "Monojit", "" ], [ "Goswami", "Srubabati", "" ], [ "Pan", "Supriya", "" ], [ "Pavlović", "Bartol", "" ] ]
In this paper, we study the implications of the Dark Large Mixing Angle (DLMA) solutions of $\theta_{12}$ in the context of the IceCube data. We study the consequences in the measurement of the neutrino oscillation parameters namely $\theta_{23}$ and $\delta_{\rm CP}$ in light of both Large Mixing Angle (LMA) and DLMA solutions of $\theta_{12}$. We find that it will be impossible for IceCube to determine the $\delta_{\rm CP}$ and the true nature of $\theta_{12}$ i.e., LMA or DLMA at the same time. This is because of the existence of an intrinsic degeneracy at the Hamiltonian level between these parameters. Apart from that, we also identify a new degeneracy between $\theta_{23}$ and two solutions of $\theta_{12}$ for a fixed value of $\delta_{\rm CP}$. We perform a chi-square fit using three different astrophysical sources, i.e., $\mu$ source, $\pi$ source, and $n$ source to find that both $\mu$ source and $\pi$ source are allowed within $1 \sigma$ whereas the $n$ source is excluded at $2 \sigma$. It is difficult to make any conclusion regarding the measurement of $\theta_{23}$, $\delta_{\rm CP}$ for $\mu$ source. However, The $\pi$ ($n$) source prefers higher (lower) octant of $\theta_{23}$ for both LMA and DLMA solution of $\theta_{12}$. The best-fit value of $\delta_{\rm CP}$ is around $180^\circ$ ($0^\circ/360^\circ$) for LMA (DLMA) solution of $\theta_{12}$ whereas for DLMA (LMA) solution of $\theta_{12}$, the best-fit value is around $0^\circ/360^\circ$ ($180^\circ$) for $\pi$ ($n$) source. If we assume the current best-fit values of $\theta_{23}$ and $\delta_{\rm CP}$ to be true, then the $\mu$ and $\pi$ source prefer the LMA solution of $\theta_{12}$ whereas the $n$ source prefers the DLMA solution of $\theta_{12}$.
hep-ph/9805342
Anatoly Radyushkin
A.V. Radyushkin
Double distributions and evolution equations
21 pages, Latex, 8 figures. To appear in Phys. Rev. D
Phys.Rev.D59:014030,1999
10.1103/PhysRevD.59.014030
JLAB-THY-98-16
hep-ph
null
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive meson electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements < p'| O(0,z) | p > of quark and gluon light-cone operators. In our previous papers we used two types of nonperturbative functions parametrizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F_\zeta(X;t). Here we discuss in more detail the double distributions (DD's) and evolution equations which they satisfy. We propose simple models for F(x,y;t=0) DD's with correct spectral and symmetry properties which also satisfy the reduction relations connecting them to the usual parton densities f(x). In this way, we obtain self-consistent models for the \zeta-dependence of nonforward distributions. We show that, for small \zeta, one can easily obtain nonforward distributions (in the X > \zeta region) from the parton densities: F_\zeta (X;t=0) \approx f(X-\zeta/2).
[ { "created": "Fri, 15 May 1998 19:40:35 GMT", "version": "v1" }, { "created": "Mon, 25 May 1998 13:08:28 GMT", "version": "v2" }, { "created": "Thu, 28 May 1998 09:18:51 GMT", "version": "v3" }, { "created": "Wed, 3 Jun 1998 15:11:43 GMT", "version": "v4" }, { "cr...
2014-11-17
[ [ "Radyushkin", "A. V.", "" ] ]
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive meson electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements < p'| O(0,z) | p > of quark and gluon light-cone operators. In our previous papers we used two types of nonperturbative functions parametrizing such matrix elements: double distributions F(x,y;t) and nonforward distribution functions F_\zeta(X;t). Here we discuss in more detail the double distributions (DD's) and evolution equations which they satisfy. We propose simple models for F(x,y;t=0) DD's with correct spectral and symmetry properties which also satisfy the reduction relations connecting them to the usual parton densities f(x). In this way, we obtain self-consistent models for the \zeta-dependence of nonforward distributions. We show that, for small \zeta, one can easily obtain nonforward distributions (in the X > \zeta region) from the parton densities: F_\zeta (X;t=0) \approx f(X-\zeta/2).
1803.00945
Ferruccio Feruglio
Claudia Cornella, Ferruccio Feruglio and Paride Paradisi
Low-energy Effects of Lepton Flavour Universality Violation
24 pages, 2 figures
null
10.1007/JHEP11(2018)012
ZU-TH-09/18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The persisting anomalous data in semileptonic B-decays point towards New Physics models exhibiting large sources of Lepton Flavour Universality Violation. In this work we generalise previous studies by considering frameworks which include an enlarged set of semileptonic four-fermion operators invariant under the SM gauge group, with New Physics affecting mainly the third generation. We derive the low-energy effective Lagrangian including the leading electroweak corrections, mandatory to obtain reliable predictions. As a particularly interesting case, we analyse the scenario where the dominant New Physics effects are encoded in the Wilson coefficient C_9, as favoured by global fit analyses of b -> s data. We find that also in this case the stringent experimental bounds on Z-pole observables and tau decays challenge a simultaneous explanation of charged and neutral-current non-standard data.
[ { "created": "Fri, 2 Mar 2018 16:45:50 GMT", "version": "v1" } ]
2018-11-14
[ [ "Cornella", "Claudia", "" ], [ "Feruglio", "Ferruccio", "" ], [ "Paradisi", "Paride", "" ] ]
The persisting anomalous data in semileptonic B-decays point towards New Physics models exhibiting large sources of Lepton Flavour Universality Violation. In this work we generalise previous studies by considering frameworks which include an enlarged set of semileptonic four-fermion operators invariant under the SM gauge group, with New Physics affecting mainly the third generation. We derive the low-energy effective Lagrangian including the leading electroweak corrections, mandatory to obtain reliable predictions. As a particularly interesting case, we analyse the scenario where the dominant New Physics effects are encoded in the Wilson coefficient C_9, as favoured by global fit analyses of b -> s data. We find that also in this case the stringent experimental bounds on Z-pole observables and tau decays challenge a simultaneous explanation of charged and neutral-current non-standard data.
1710.01515
Abhishek Iyer M
A.Deandrea, A.M. Iyer
Vector-like quarks and heavy coloured bosons at the LHC
13 Pages, 4 Figures
Phys. Rev. D 97, 055002 (2018)
10.1103/PhysRevD.97.055002
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the production of heavy coloured scalars and vectors and their relevance at LHC for the study of vector-like quarks ($T$). These coloured states ($C$) are present in a large number of extensions of the standard model, in particular in composite models and in extra dimensional models. Assuming that these bosonic states are heavier than the vector-like quarks (VLQ), we consider their production through the process $p~p\rightarrow C\rightarrow tT$. Large QCD production cross-sections for $C$ enable us to probe heavier masses for the VLQ and thereby allowing to put stronger limits on the vector-like quarks which are produced in their decay chain. We adopt a universal analysis strategy by including leptons under the classification of `jets', thereby limiting the bias towards a specific combination of final state. We also study the possibility of disentangling these scenarios from supersymmetric extensions of the Standard Model by using simple discriminants based on jet multiplicity and missing energy. We demonstrate that a simple set of cuts are sufficient to disentangle the VLQ signal from the backgrounds. In models with a moderate $B.R.(C\rightarrow Tt)$, the analysis enables one to get a hint of VLQ masses as heavy as 3 TeV.
[ { "created": "Wed, 4 Oct 2017 09:23:13 GMT", "version": "v1" } ]
2018-03-14
[ [ "Deandrea", "A.", "" ], [ "Iyer", "A. M.", "" ] ]
We investigate the production of heavy coloured scalars and vectors and their relevance at LHC for the study of vector-like quarks ($T$). These coloured states ($C$) are present in a large number of extensions of the standard model, in particular in composite models and in extra dimensional models. Assuming that these bosonic states are heavier than the vector-like quarks (VLQ), we consider their production through the process $p~p\rightarrow C\rightarrow tT$. Large QCD production cross-sections for $C$ enable us to probe heavier masses for the VLQ and thereby allowing to put stronger limits on the vector-like quarks which are produced in their decay chain. We adopt a universal analysis strategy by including leptons under the classification of `jets', thereby limiting the bias towards a specific combination of final state. We also study the possibility of disentangling these scenarios from supersymmetric extensions of the Standard Model by using simple discriminants based on jet multiplicity and missing energy. We demonstrate that a simple set of cuts are sufficient to disentangle the VLQ signal from the backgrounds. In models with a moderate $B.R.(C\rightarrow Tt)$, the analysis enables one to get a hint of VLQ masses as heavy as 3 TeV.
1209.0144
Shunsuke Ohkoda
Shunsuke Ohkoda, Y. Yamaguchi, S. Yasui, K. Sudoh, A. Hosaka
Exotic mesons with hidden charm and bottom near thresholds
10 pages, 1 figure, to appear in the proceedings of The 5th International Workshop on Charm Physics (Charm 2012)
null
10.1007/s00601-013-0609-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study heavy hadron spectroscopy near heavy meson thresholds. We employ heavy pseudoscalar meson P and heavy vector meson P* as effective degrees of freedom and consider meson exchange potentials between them. All possible composite states which can be constructed from the P and P* mesons are studied up to the total angular momentum J <= 2. We consider, as exotic states, isosinglet states with exotic J^{PC} quantum numbers and isotriplet states. We solve numerically the Schr\"odinger equation with channel-couplings for each state. We found B(*)barB(*) molecule states for I^G(J^{PC}) = 1^+(1^{+-}) correspond to the masses of twin resonances Zb(10610) and Zb(10650). We predict several possible B(*)barB(*) bound and/or resonant states in other channels. On the other hand, there are no B(*)barB(*) bound and/or resonant states whose quantum numbers are exotic.
[ { "created": "Sun, 2 Sep 2012 02:14:10 GMT", "version": "v1" }, { "created": "Wed, 5 Sep 2012 13:33:03 GMT", "version": "v2" } ]
2015-06-11
[ [ "Ohkoda", "Shunsuke", "" ], [ "Yamaguchi", "Y.", "" ], [ "Yasui", "S.", "" ], [ "Sudoh", "K.", "" ], [ "Hosaka", "A.", "" ] ]
We study heavy hadron spectroscopy near heavy meson thresholds. We employ heavy pseudoscalar meson P and heavy vector meson P* as effective degrees of freedom and consider meson exchange potentials between them. All possible composite states which can be constructed from the P and P* mesons are studied up to the total angular momentum J <= 2. We consider, as exotic states, isosinglet states with exotic J^{PC} quantum numbers and isotriplet states. We solve numerically the Schr\"odinger equation with channel-couplings for each state. We found B(*)barB(*) molecule states for I^G(J^{PC}) = 1^+(1^{+-}) correspond to the masses of twin resonances Zb(10610) and Zb(10650). We predict several possible B(*)barB(*) bound and/or resonant states in other channels. On the other hand, there are no B(*)barB(*) bound and/or resonant states whose quantum numbers are exotic.
1310.8484
Andrej Arbuzov
M.K. Volkov, A.B. Arbuzov, D.G. Kostunin
The process $e^+e^- \to \eta(\eta')2\pi$ in the extended NJL model
Estimations for decays $\tau\to\eta(\eta')2\pi\nu$ widths are added
Phys. Rev. C 89, 015202 (2014)
10.1103/PhysRevC.89.015202
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Process of electron-positron annihilation into $\eta(\eta')2\pi$ is described within the extended NJL model in the energy range up to about 2 GeV. Contributions of intermediate vector mesons $\rho(770)$ and $\rho(1450)$ are taken into account. Results for the $\eta2\pi$ channel are found to be in a reasonable agreement with experimental data. Predictions for production of $\eta' 2\pi$ are given. The corresponding estimations for decays $\tau\to\eta(\eta')2\pi\nu$ are given in Appendix.
[ { "created": "Thu, 31 Oct 2013 13:04:55 GMT", "version": "v1" }, { "created": "Thu, 5 Dec 2013 06:21:28 GMT", "version": "v2" } ]
2014-01-15
[ [ "Volkov", "M. K.", "" ], [ "Arbuzov", "A. B.", "" ], [ "Kostunin", "D. G.", "" ] ]
Process of electron-positron annihilation into $\eta(\eta')2\pi$ is described within the extended NJL model in the energy range up to about 2 GeV. Contributions of intermediate vector mesons $\rho(770)$ and $\rho(1450)$ are taken into account. Results for the $\eta2\pi$ channel are found to be in a reasonable agreement with experimental data. Predictions for production of $\eta' 2\pi$ are given. The corresponding estimations for decays $\tau\to\eta(\eta')2\pi\nu$ are given in Appendix.
0811.4174
Claudia Ratti
Claudia Ratti, Edward Shuryak
The role of monopoles in a Gluon Plasma
60 pages, 15 Figures
Phys.Rev.D80:034004,2009
10.1103/PhysRevD.80.034004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the role of magnetic monopoles at high enough temperature $T>2T_c$, when they can be considered heavy, rare objects embedded into matter consisting mostly of the usual "electric" quasiparticles, quarks and gluons. We review available lattice results on monopoles at finite temperatures. Then we proceed to classical and quantum charge-monopole scattering, solving the problem of gluon-monopole scattering for the first time. We find that, while this process hardly influences thermodynamic quantities, it does produce a large transport cross section, significantly exceeding that for pQCD gluon-gluon scattering up to quite high $T$. Thus, in spite of their relatively small density at high $T$, monopoles are extremely important for QGP transport properties, keeping viscosity small enough for hydrodynamics to work at LHC.
[ { "created": "Tue, 25 Nov 2008 21:00:36 GMT", "version": "v1" } ]
2009-09-02
[ [ "Ratti", "Claudia", "" ], [ "Shuryak", "Edward", "" ] ]
We study the role of magnetic monopoles at high enough temperature $T>2T_c$, when they can be considered heavy, rare objects embedded into matter consisting mostly of the usual "electric" quasiparticles, quarks and gluons. We review available lattice results on monopoles at finite temperatures. Then we proceed to classical and quantum charge-monopole scattering, solving the problem of gluon-monopole scattering for the first time. We find that, while this process hardly influences thermodynamic quantities, it does produce a large transport cross section, significantly exceeding that for pQCD gluon-gluon scattering up to quite high $T$. Thus, in spite of their relatively small density at high $T$, monopoles are extremely important for QGP transport properties, keeping viscosity small enough for hydrodynamics to work at LHC.
hep-ph/0202082
Gudrid Moortgat-Pick
Gudrid Moortgat--Pick (DESY)
Impact of beam polarization at a future linear collider
7 pages, 5 eps figures, Contribution to Snowmass 2001 Summer Study
eConf C010630:E3008,2001
null
null
hep-ph
null
Beam polarization at e^+e^- linear colliders will be a powerful tool for high precision analyses. In this paper we summarize the polarization-related results for Higgs and electroweak physics, QCD, Supersymmetry and alternative theories beyond the Standard Model. Most studies were made for a planned linear collider operating in the energy range sqrt{s}= 500-800 GeV. In particular we work out the advantages of simultaneous polarization of the electron and positron beam.
[ { "created": "Fri, 8 Feb 2002 17:18:32 GMT", "version": "v1" } ]
2011-01-13
[ [ "Moortgat--Pick", "Gudrid", "", "DESY" ] ]
Beam polarization at e^+e^- linear colliders will be a powerful tool for high precision analyses. In this paper we summarize the polarization-related results for Higgs and electroweak physics, QCD, Supersymmetry and alternative theories beyond the Standard Model. Most studies were made for a planned linear collider operating in the energy range sqrt{s}= 500-800 GeV. In particular we work out the advantages of simultaneous polarization of the electron and positron beam.
hep-ph/0006357
B. F. L. Ward
B.F.L. Ward (1, 2 and 3), ((1) Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee, (2) SLAC, Stanford University, Stanford, California, (3) TH Div., CERN, Geneva, Switzerland)
CP Violation in Exclusive B Decays: Recoil Phase Effect
12 pages, 6 figures; replaced fig. 5 and its attendant discussion; added affiliation; corrected typos; new title for journal
null
null
UTHEP-00-0102
hep-ph
null
In the perturbative QCD approach to exclusive B decays to two light mesons, the leading twist contribution corresponds to those diagrams in the Lepage-Brodsky expansion in which the would be spectator quark receives its recoil momentum via one gluon exchange. We show that the resulting amplitude, which in the spectator model is real, acquires an imaginary part which may be comparable in size to its real part. Thus, this source of the strong interaction phase in the amplitude must be taken into account in general to discuss, reliably, the expectations for CP violation in B decays at any B-Factory type scenario.
[ { "created": "Fri, 30 Jun 2000 20:04:09 GMT", "version": "v1" }, { "created": "Mon, 3 Jul 2000 11:37:55 GMT", "version": "v2" }, { "created": "Fri, 11 Aug 2000 18:43:06 GMT", "version": "v3" }, { "created": "Tue, 10 Jul 2001 09:01:13 GMT", "version": "v4" } ]
2009-09-25
[ [ "Ward", "B. F. L.", "", "1, 2 and 3" ] ]
In the perturbative QCD approach to exclusive B decays to two light mesons, the leading twist contribution corresponds to those diagrams in the Lepage-Brodsky expansion in which the would be spectator quark receives its recoil momentum via one gluon exchange. We show that the resulting amplitude, which in the spectator model is real, acquires an imaginary part which may be comparable in size to its real part. Thus, this source of the strong interaction phase in the amplitude must be taken into account in general to discuss, reliably, the expectations for CP violation in B decays at any B-Factory type scenario.
2312.05870
Wei-Jie Fu
Yong-rui Chen, Yang-yang Tan, Wei-jie Fu
Critical dynamics within the real-time fRG approach
11 pages, 11 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
The Schwinger-Keldysh functional renormalization group (fRG) developed in [1] is employed to investigate critical dynamics related to a second-order phase transition. The effective action of model A is expanded to the order of $O(\partial^2)$ in the derivative expansion for the $O(N)$ symmetry. By solving the fixed-point equations of effective potential and wave function, we obtain static and dynamic critical exponents for different values of the spatial dimension $d$ and the field component number $N$. It is found that one has $z \geq 2$ in the whole range of $2\leq d\leq 4$ for the case of $N=1$, while in the case of $N=4$ the dynamic critical exponent turns to $z < 2$ when the dimension approach towards $d=2$.
[ { "created": "Sun, 10 Dec 2023 12:44:17 GMT", "version": "v1" } ]
2023-12-12
[ [ "Chen", "Yong-rui", "" ], [ "Tan", "Yang-yang", "" ], [ "Fu", "Wei-jie", "" ] ]
The Schwinger-Keldysh functional renormalization group (fRG) developed in [1] is employed to investigate critical dynamics related to a second-order phase transition. The effective action of model A is expanded to the order of $O(\partial^2)$ in the derivative expansion for the $O(N)$ symmetry. By solving the fixed-point equations of effective potential and wave function, we obtain static and dynamic critical exponents for different values of the spatial dimension $d$ and the field component number $N$. It is found that one has $z \geq 2$ in the whole range of $2\leq d\leq 4$ for the case of $N=1$, while in the case of $N=4$ the dynamic critical exponent turns to $z < 2$ when the dimension approach towards $d=2$.
0709.0950
David Morrissey
Yanou Cui, Stephen P. Martin, David E. Morrissey, James D. Wells
Cosmic Strings from Supersymmetric Flat Directions
58 pages, 16 figures, v2. accepted to PRD, added comments about baryogenesis and boosted decay products from cusp annihilation
Phys.Rev.D77:043528,2008
10.1103/PhysRevD.77.043528
MCTP-07-28, CERN-PH-TH/2007-151
hep-ph astro-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Flat directions are a generic feature of the scalar potential in supersymmetric gauge field theories. They can arise, for example, from D-terms associated with an extra abelian gauge symmetry. Even when supersymmetry is broken softly, there often remain directions in the scalar field space along which the potential is almost flat. Upon breaking a gauge symmetry along one of these almost flat directions, cosmic strings may form. Relative to the standard cosmic string picture based on the abelian Higgs model, these flat-direction cosmic strings have the extreme Type-I properties of a thin gauge core surrounded by a much wider scalar field profile. We perform a comprehensive study of the microscopic, macroscopic, and observational characteristics of this class of strings. We find many differences from the standard string scenario, including stable higher winding mode strings, the dynamical formation of higher mode strings from lower ones, and a resultant multi-tension scaling string network in the early universe. These strings are only moderately constrained by current observations, and their gravitational wave signatures may be detectable at future gravity wave detectors. Furthermore, there is the interesting but speculative prospect that the decays of cosmic string loops in the early universe could be a source of ultra-high energy cosmic rays or non-thermal dark matter. We also compare the observational signatures of flat-direction cosmic strings with those of ordinary cosmic strings as well as (p,q) cosmic strings motivated by superstring theory.
[ { "created": "Thu, 6 Sep 2007 20:18:29 GMT", "version": "v1" }, { "created": "Fri, 18 Jul 2008 20:58:37 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cui", "Yanou", "" ], [ "Martin", "Stephen P.", "" ], [ "Morrissey", "David E.", "" ], [ "Wells", "James D.", "" ] ]
Flat directions are a generic feature of the scalar potential in supersymmetric gauge field theories. They can arise, for example, from D-terms associated with an extra abelian gauge symmetry. Even when supersymmetry is broken softly, there often remain directions in the scalar field space along which the potential is almost flat. Upon breaking a gauge symmetry along one of these almost flat directions, cosmic strings may form. Relative to the standard cosmic string picture based on the abelian Higgs model, these flat-direction cosmic strings have the extreme Type-I properties of a thin gauge core surrounded by a much wider scalar field profile. We perform a comprehensive study of the microscopic, macroscopic, and observational characteristics of this class of strings. We find many differences from the standard string scenario, including stable higher winding mode strings, the dynamical formation of higher mode strings from lower ones, and a resultant multi-tension scaling string network in the early universe. These strings are only moderately constrained by current observations, and their gravitational wave signatures may be detectable at future gravity wave detectors. Furthermore, there is the interesting but speculative prospect that the decays of cosmic string loops in the early universe could be a source of ultra-high energy cosmic rays or non-thermal dark matter. We also compare the observational signatures of flat-direction cosmic strings with those of ordinary cosmic strings as well as (p,q) cosmic strings motivated by superstring theory.
2303.15388
Jorge Segovia
Gang Yang, Jialun Ping and Jorge Segovia
Charmoniumlike tetraquarks in a chiral quark model
22 pages, 10 figures, 21 tables. arXiv admin note: text overlap with arXiv:2101.04933, arXiv:2204.08556, arXiv:2109.04311
null
null
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The lowest-lying charmonium-like tetraquarks $c\bar{c}q\bar{q}$ $(q=u,\,d)$ and $c\bar{c}s\bar{s}$, with spin-parity $J^P=0^+$, $1^+$ and $2^+$, and isospin $I=0$ and $1$, are systematically investigated within the theoretical framework of complex-scaling range for a chiral quark model that has already been successfully applied in former studies of various tetra- and penta-quark systems. A four-body $S$-wave configuration which includes meson-meson, diquark-antidiquark and K-type arrangements of quarks, along with all possible color wave functions, is comprehensively considered. Several narrow resonances are obtained in each tetraquark channel when a fully coupled-channel computation is performed. We tentatively assign theoretical states to experimentally reported charmonium-like signals such as $X(3872)$, $Z_c(3900)$, $X(3960)$, $X(4350)$, $X(4685)$ and $X(4700)$. They can be well identified as hadronic molecules; however, other exotic components which involve, for instance, hidden-color channels or diquark-antidiquark structures play a considerable role. Meanwhile, two resonances are obtained at $4.04$ GeV and $4.14$ GeV which may be compatible with experimental data in the energy interval $4.0-4.2$ GeV. Furthermore, the $X(3940)$ and $X(4630)$ may be identified as color compact tetraquark resonances. Finally, we also find few resonance states in the energy interval from $4.5$ GeV to $5.0$ GeV, which would be awaiting for discovery in future experiments.
[ { "created": "Mon, 27 Mar 2023 17:00:37 GMT", "version": "v1" } ]
2023-03-28
[ [ "Yang", "Gang", "" ], [ "Ping", "Jialun", "" ], [ "Segovia", "Jorge", "" ] ]
The lowest-lying charmonium-like tetraquarks $c\bar{c}q\bar{q}$ $(q=u,\,d)$ and $c\bar{c}s\bar{s}$, with spin-parity $J^P=0^+$, $1^+$ and $2^+$, and isospin $I=0$ and $1$, are systematically investigated within the theoretical framework of complex-scaling range for a chiral quark model that has already been successfully applied in former studies of various tetra- and penta-quark systems. A four-body $S$-wave configuration which includes meson-meson, diquark-antidiquark and K-type arrangements of quarks, along with all possible color wave functions, is comprehensively considered. Several narrow resonances are obtained in each tetraquark channel when a fully coupled-channel computation is performed. We tentatively assign theoretical states to experimentally reported charmonium-like signals such as $X(3872)$, $Z_c(3900)$, $X(3960)$, $X(4350)$, $X(4685)$ and $X(4700)$. They can be well identified as hadronic molecules; however, other exotic components which involve, for instance, hidden-color channels or diquark-antidiquark structures play a considerable role. Meanwhile, two resonances are obtained at $4.04$ GeV and $4.14$ GeV which may be compatible with experimental data in the energy interval $4.0-4.2$ GeV. Furthermore, the $X(3940)$ and $X(4630)$ may be identified as color compact tetraquark resonances. Finally, we also find few resonance states in the energy interval from $4.5$ GeV to $5.0$ GeV, which would be awaiting for discovery in future experiments.
0801.2414
Gudrid Moortgat-Pick
Gudrid Moortgat-Pick
LHC/ILC Interplay in SUSY Searches
5 pages, contribution to the proceedings of EPS07
J.Phys.Conf.Ser.110:072027,2008
10.1088/1742-6596/110/7/072027
IPPP/07/70, DCPT/07/140
hep-ph
null
Combined analyses at the Large Hadron Collider and at the International Linear Collider are important to reveal precisely the new physics model as, for instance, supersymmetry. Examples are presented where ILC results as input for LHC analyses could be crucial for the identification of signals as well as of the underlying model. The synergy of both colliders leads also to rather accurate SUSY parameter determination and powerful mass constraints even if the scalar particles have masses in the multi-TeV range.
[ { "created": "Wed, 16 Jan 2008 01:15:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Moortgat-Pick", "Gudrid", "" ] ]
Combined analyses at the Large Hadron Collider and at the International Linear Collider are important to reveal precisely the new physics model as, for instance, supersymmetry. Examples are presented where ILC results as input for LHC analyses could be crucial for the identification of signals as well as of the underlying model. The synergy of both colliders leads also to rather accurate SUSY parameter determination and powerful mass constraints even if the scalar particles have masses in the multi-TeV range.
hep-ph/9809438
Christoph Greub
F. Borzumati (Montpellier) and C. Greub (Bern)
Addendum to: 2HDMs predictions for $B \to X_s \gamma$ in NLO QCD
4 pages including 1 postscript figure; uses epsfig. Addendum to hep-ph/9802391
Phys.Rev.D59:057501,1999
10.1103/PhysRevD.59.057501
PM/98-22, BUTP-98/24
hep-ph
null
We update our work ``Two Higgs Doublet Model predictions for B->X_s gamma in NLO QCD'', hep-ph/9802391 by taking into account the recently calculated electromagnetic corrections. We present a new exclusion contour plot (tan(\beta),m_H), where these corrections are included.
[ { "created": "Thu, 17 Sep 1998 19:13:02 GMT", "version": "v1" } ]
2011-01-05
[ [ "Borzumati", "F.", "", "Montpellier" ], [ "Greub", "C.", "", "Bern" ] ]
We update our work ``Two Higgs Doublet Model predictions for B->X_s gamma in NLO QCD'', hep-ph/9802391 by taking into account the recently calculated electromagnetic corrections. We present a new exclusion contour plot (tan(\beta),m_H), where these corrections are included.
2302.01956
Juliane Haug
Juliane Haug and Fabian Wunder
The massless non-adjacent double off-shell scalar box integral -- branch cut structure and all-order epsilon expansion
8 pages, 1 figure, updated to match version published in JHEP
JHEP 05 (2023) 059
10.1007/JHEP05(2023)059
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We generalize the result of our recent paper on the massless single off-shell scalar box integral to the case of two non-adjacent end points off the light cone. An analytic result in $d=4-2\varepsilon$ dimensions is established in terms of four Gauss hypergeometric ${_2}\mathrm{F}_1$ functions respectively their single-valued counterparts. This allows for an explicit splitting of real and imaginary parts, as well as an all-order $\varepsilon$-expansion in terms of single-valued polylogarithms.
[ { "created": "Fri, 3 Feb 2023 19:07:45 GMT", "version": "v1" }, { "created": "Wed, 8 Feb 2023 17:21:01 GMT", "version": "v2" }, { "created": "Wed, 10 May 2023 15:34:00 GMT", "version": "v3" } ]
2023-05-11
[ [ "Haug", "Juliane", "" ], [ "Wunder", "Fabian", "" ] ]
We generalize the result of our recent paper on the massless single off-shell scalar box integral to the case of two non-adjacent end points off the light cone. An analytic result in $d=4-2\varepsilon$ dimensions is established in terms of four Gauss hypergeometric ${_2}\mathrm{F}_1$ functions respectively their single-valued counterparts. This allows for an explicit splitting of real and imaginary parts, as well as an all-order $\varepsilon$-expansion in terms of single-valued polylogarithms.
0804.3053
Peter Richardson
M. Bahr, S. Gieseke, M. Gigg, D. Grellscheid, K. Hamilton, O. Latunde-Dada, S. Platzer, P. Richardson, M. H. Seymour, A. Sherstnev, B. R. Webber
Herwig++ 2.2 Release Note
5 pages
null
null
Cavendish-HEP-08/05, CERN-PH-TH/2008-080, CP3-08-08, IPPP/08/26, DCPT/08/52, KA-TP-09-2008
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new release of the Monte Carlo program Herwig++ (version 2.2) is now available. This version includes a number of improvements including: matrix elements for the production of an electroweak gauge boson, W and Z, in association with a jet; several new processes for Higgs production in association with an electroweak gauge boson; and the matrix element correction for QCD radiation in Higgs production via gluon fusion.
[ { "created": "Fri, 18 Apr 2008 15:49:27 GMT", "version": "v1" } ]
2008-04-21
[ [ "Bahr", "M.", "" ], [ "Gieseke", "S.", "" ], [ "Gigg", "M.", "" ], [ "Grellscheid", "D.", "" ], [ "Hamilton", "K.", "" ], [ "Latunde-Dada", "O.", "" ], [ "Platzer", "S.", "" ], [ "Richardson", "...
A new release of the Monte Carlo program Herwig++ (version 2.2) is now available. This version includes a number of improvements including: matrix elements for the production of an electroweak gauge boson, W and Z, in association with a jet; several new processes for Higgs production in association with an electroweak gauge boson; and the matrix element correction for QCD radiation in Higgs production via gluon fusion.
hep-ph/0212083
Jose Bordes
J. Bordes, J. Penarrocha and K. Schilcher
Bottom quark mass and QCD duality
10 pages, 2 figures
Phys.Lett.B562:81-86,2003
10.1016/S0370-2693(03)00542-2
MZ-TH/02-31, FTUV-0412/02
hep-ph
null
The mass of the bottom quark is analyzed in the context of QCD finite energy sum rules. In contrast to the conventional approach, we use a large momentum expansion of the QCD correlator including terms to order \alpha _{s}^{2}(m_{b}^{2}/q^{2})^{6} with the upsilon resonances from e^{+}e^{-} annihilation data as main input. A stable result m_{b}(m_{b})=4.19\pm 0.05 GeV} for the bottom quark mass is obtained. This result agrees with the independent calculations based on the inverse moment analysis.
[ { "created": "Thu, 5 Dec 2002 14:43:56 GMT", "version": "v1" }, { "created": "Fri, 21 Mar 2003 11:36:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bordes", "J.", "" ], [ "Penarrocha", "J.", "" ], [ "Schilcher", "K.", "" ] ]
The mass of the bottom quark is analyzed in the context of QCD finite energy sum rules. In contrast to the conventional approach, we use a large momentum expansion of the QCD correlator including terms to order \alpha _{s}^{2}(m_{b}^{2}/q^{2})^{6} with the upsilon resonances from e^{+}e^{-} annihilation data as main input. A stable result m_{b}(m_{b})=4.19\pm 0.05 GeV} for the bottom quark mass is obtained. This result agrees with the independent calculations based on the inverse moment analysis.
hep-ph/0210201
Alexander Penin
A.A. Penin
Potential Nonrelativistic QCD and Heavy Quarkonium Spectrum in Next-to-Next-to-Next-to-Leading Order
5 pages LaTeX, Talk presented at RADCOR/LL 2002 conference, Kloster Banz, Germany, September 8-13, 2002
Nucl.Phys.Proc.Suppl. 116 (2003) 373-377
10.1016/S0920-5632(03)80202-5
null
hep-ph
null
In this talk I review the calculation of the third order corrections to the heavy quarkonium spectrum in the nonrelativistic effective theory framework and its application to the phenomenology of top quark threshold production.
[ { "created": "Mon, 14 Oct 2002 10:55:56 GMT", "version": "v1" } ]
2009-11-07
[ [ "Penin", "A. A.", "" ] ]
In this talk I review the calculation of the third order corrections to the heavy quarkonium spectrum in the nonrelativistic effective theory framework and its application to the phenomenology of top quark threshold production.
0712.1016
Thomas Binoth Dr.
A. D. Kennedy, T. Binoth, T. Rippon
Automating Renormalization of Quantum Field Theories
Invited talk given by A.D. Kennedy at the International Workshop on Symbolic-Numeric Computation'07, University of Western Ontario, Canada
Proceedings of the 2007 international workshop on Symbolic-numeric computation, London, Ontario, Canada, 18-27 (2007). ISBN:978-1-59593-744-5
null
Edinburgh 2007/46
hep-ph
null
We give an overview of state-of-the-art multi-loop Feynman diagram computations, and explain how we use symbolic manipulation to generate renormalized integrals that are then evaluated numerically. We explain how we automate BPHZ renormalization using "henges" and "sectors", and give a brief description of the symbolic tensor and Dirac gamma-matrix manipulation that is required. We shall compare the use of general computer algebra systems such as Maple with domain-specific languages such as FORM, highlighting in particular memory management issues.
[ { "created": "Thu, 6 Dec 2007 19:33:28 GMT", "version": "v1" } ]
2007-12-07
[ [ "Kennedy", "A. D.", "" ], [ "Binoth", "T.", "" ], [ "Rippon", "T.", "" ] ]
We give an overview of state-of-the-art multi-loop Feynman diagram computations, and explain how we use symbolic manipulation to generate renormalized integrals that are then evaluated numerically. We explain how we automate BPHZ renormalization using "henges" and "sectors", and give a brief description of the symbolic tensor and Dirac gamma-matrix manipulation that is required. We shall compare the use of general computer algebra systems such as Maple with domain-specific languages such as FORM, highlighting in particular memory management issues.
hep-ph/0005080
Sacha Davidson
Sacha Davidson, Marta Losada
Neutrino masses in the R-parity violating MSSM
mass dimensions in column four of table corrected
JHEP 0005 (2000) 021
10.1088/1126-6708/2000/05/021
null
hep-ph
null
We compute one loop neutrino masses in the R-parity violating Minimal Supersymmetric Model, including the bilinear R-parity violating masses in the mass insertion approximation. To the order we calculate, our results are independent of the Higgs-lepton basis choice. We have a variety of perturbative parameters-gauge, yukawa and trilinear couplings, and R_p violating masses. Their relative magnitudes determine which diagrams are relevant for neutrino mass calculations. We find new loop diagrams which can be relevant and have frequently been neglected in the past. For the Grossman-Haber neutral loop contribution to the neutrino mass matrix we obtain explicit analytic results.
[ { "created": "Tue, 9 May 2000 12:59:24 GMT", "version": "v1" }, { "created": "Tue, 13 Jun 2000 20:08:32 GMT", "version": "v2" }, { "created": "Mon, 6 Nov 2000 14:01:25 GMT", "version": "v3" } ]
2009-10-31
[ [ "Davidson", "Sacha", "" ], [ "Losada", "Marta", "" ] ]
We compute one loop neutrino masses in the R-parity violating Minimal Supersymmetric Model, including the bilinear R-parity violating masses in the mass insertion approximation. To the order we calculate, our results are independent of the Higgs-lepton basis choice. We have a variety of perturbative parameters-gauge, yukawa and trilinear couplings, and R_p violating masses. Their relative magnitudes determine which diagrams are relevant for neutrino mass calculations. We find new loop diagrams which can be relevant and have frequently been neglected in the past. For the Grossman-Haber neutral loop contribution to the neutrino mass matrix we obtain explicit analytic results.
hep-ph/9910527
Avtandil Tkabladze
J. Gegelia, G. Japaridze, A. Tkabladze, A. Khelashvili, and K. Turashvili
On the Gauge Invariance of the Z-Boson Mass
11 pages, LaTeX, talk presented at the Conference "Quarks-92", Zvenigorod Russia, 1992, comments added
null
null
null
hep-ph
null
The different schemes for the definition of the Z boson mass are analyzed. It is shown that the scheme, defining the mass as pole of the real part of the Z boson propagator and the width as the imaginary part of the propagator at the same point results in the gauge dependent results for these parameters in a two-loop approximation. On the other hand, the scheme, where the mass and width are related to the position of the pole of the propagator in the complex plane leads to the gauge independent result. It is argued that the gauge dependence of mass and width does not contradicts to the gauge invariance of the amplitude.
[ { "created": "Thu, 28 Oct 1999 19:19:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gegelia", "J.", "" ], [ "Japaridze", "G.", "" ], [ "Tkabladze", "A.", "" ], [ "Khelashvili", "A.", "" ], [ "Turashvili", "K.", "" ] ]
The different schemes for the definition of the Z boson mass are analyzed. It is shown that the scheme, defining the mass as pole of the real part of the Z boson propagator and the width as the imaginary part of the propagator at the same point results in the gauge dependent results for these parameters in a two-loop approximation. On the other hand, the scheme, where the mass and width are related to the position of the pole of the propagator in the complex plane leads to the gauge independent result. It is argued that the gauge dependence of mass and width does not contradicts to the gauge invariance of the amplitude.
1310.6701
Yuri V. Kovchegov
Yuri V. Kovchegov, Douglas E. Wertepny
Two-Gluon Correlations in Heavy-Light Ion Collisions: Energy and Geometry Dependence, IR Divergences, and $k_T$-Factorization
30 pages, 6 figures; v2: typos corrected, references added
null
10.1016/j.nuclphysa.2014.02.021
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the properties of the cross section for two-gluon production in heavy-light ion collisions derived in our previous paper on the subject in the saturation/Color Glass Condensate framework. Concentrating on the energy and geometry dependence of the corresponding correlation functions we find that the two-gluon correlator is a much slower function of the center-of-mass energy than the one- and two-gluon production cross sections. The geometry dependence of the correlation function leads to stronger azimuthal near- and away-side correlations in the tip-on-tip U+U collisions than in the side-on-side U+U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark-gluon plasma: a study of azimuthal correlations in the U+U collisions may thus help to disentangle the two sources of correlations. We demonstrate that the cross section for two-gluon production in heavy-light ion collisions contains a power-law infrared (IR) divergence even for fixed produced gluon momenta: while saturation effects in the target regulate some of the power-law IR-divergent terms in the lowest-order expression for the two-gluon correlator, other power-law IR-divergent terms remain, possibly due to absence of saturation effects in the dilute projectile. Finally we rewrite our result for the two-gluon production cross-section in a $k_T$-factorized form, obtaining a new factorized expression involving a convolution of one- and two-gluon Wigner distributions over both the transverse momenta and impact parameters. We show that the two-gluon production cross-section depends on two different types of unintegrated two-gluon Wigner distribution functions.
[ { "created": "Thu, 24 Oct 2013 18:42:27 GMT", "version": "v1" }, { "created": "Tue, 11 Mar 2014 16:42:25 GMT", "version": "v2" } ]
2015-06-17
[ [ "Kovchegov", "Yuri V.", "" ], [ "Wertepny", "Douglas E.", "" ] ]
We study the properties of the cross section for two-gluon production in heavy-light ion collisions derived in our previous paper on the subject in the saturation/Color Glass Condensate framework. Concentrating on the energy and geometry dependence of the corresponding correlation functions we find that the two-gluon correlator is a much slower function of the center-of-mass energy than the one- and two-gluon production cross sections. The geometry dependence of the correlation function leads to stronger azimuthal near- and away-side correlations in the tip-on-tip U+U collisions than in the side-on-side U+U collisions, an exactly opposite behavior from the correlations generated by the elliptic flow of the quark-gluon plasma: a study of azimuthal correlations in the U+U collisions may thus help to disentangle the two sources of correlations. We demonstrate that the cross section for two-gluon production in heavy-light ion collisions contains a power-law infrared (IR) divergence even for fixed produced gluon momenta: while saturation effects in the target regulate some of the power-law IR-divergent terms in the lowest-order expression for the two-gluon correlator, other power-law IR-divergent terms remain, possibly due to absence of saturation effects in the dilute projectile. Finally we rewrite our result for the two-gluon production cross-section in a $k_T$-factorized form, obtaining a new factorized expression involving a convolution of one- and two-gluon Wigner distributions over both the transverse momenta and impact parameters. We show that the two-gluon production cross-section depends on two different types of unintegrated two-gluon Wigner distribution functions.
1410.1304
Yannis Burnier
Yannis Burnier (EPFL)
Quarkonium spectral function in medium at next-to-leading order for any quark mass
22 pages, 4 figures
null
null
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The vector channel spectral function at zero spatial momentum is calculated at next-to-leading order in thermal QCD for any quark mass. It corresponds to the imaginary part of the massive quark contribution to the photon polarization tensor. The spectrum shows a well defined transport peak in contrast to both the heavy quark limit studied previously, where the low frequency domain is exponentially suppressed at this order and the naive massless case where it vanishes at leading order and diverges at next-to-leading order. From our general expressions, the massless limit can be taken and we show that no divergences occur if done carefully. Finally, we compare the massless limit to results from lattice simulations.
[ { "created": "Mon, 6 Oct 2014 09:45:00 GMT", "version": "v1" } ]
2014-10-07
[ [ "Burnier", "Yannis", "", "EPFL" ] ]
The vector channel spectral function at zero spatial momentum is calculated at next-to-leading order in thermal QCD for any quark mass. It corresponds to the imaginary part of the massive quark contribution to the photon polarization tensor. The spectrum shows a well defined transport peak in contrast to both the heavy quark limit studied previously, where the low frequency domain is exponentially suppressed at this order and the naive massless case where it vanishes at leading order and diverges at next-to-leading order. From our general expressions, the massless limit can be taken and we show that no divergences occur if done carefully. Finally, we compare the massless limit to results from lattice simulations.
hep-ph/0607257
Angels Ramos
T. Mizutani and A. Ramos
D Mesons in Nuclear Matter: A DN Coupled-Channel Equations Approach
30 pages, 8 eps figures, some typos and coefficients corrected, published in Phys. Rev. C
Phys.Rev.C74:065201,2006
10.1103/PhysRevC.74.065201
null
hep-ph nucl-th
null
A set of coupled two-body scattering equations is solved for the DN system embedded in an iso-symmetric nuclear matter. The in-medium behavior of charmed D mesons: (D^+,D^0), is investigated from the self-consistent solution within this scheme. The effective meson-baryon Lagrangian in charm quantum number one sector, the key ingredient in the present study, is adopted from a recent model by Hofmann and Lutz which has aimed at combining the charmed meson degree of freedom in a consistent manner with chiral unitary models. After a critical examination, the original model is modified in several important aspects, such as the method of regularization, in order to be more consistent and practical for our objective. The resultant interaction is used to reproduce the position and width of the s-wave \Lambda_c(2593) resonance in the isospin zero DN channel. In the isospin one channel, it generates a rather wide resonance at \~2770 MeV. The corresponding in-medium solution is then sought by incorporating Pauli blocking and the D- and \pi-meson dressing self-consistently. At normal nuclear matter density, the resultant \Lambda_c (2593) is found to stay narrow and shifted at a lower energy, while the I=1 resonance is lowered in position as well and broadened considerably. The possible implication of our findings on the J/\Psi suppression, etc. in relativistic heavy ion collisions is briefly discussed.
[ { "created": "Mon, 24 Jul 2006 07:05:27 GMT", "version": "v1" }, { "created": "Wed, 27 Dec 2006 14:32:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Mizutani", "T.", "" ], [ "Ramos", "A.", "" ] ]
A set of coupled two-body scattering equations is solved for the DN system embedded in an iso-symmetric nuclear matter. The in-medium behavior of charmed D mesons: (D^+,D^0), is investigated from the self-consistent solution within this scheme. The effective meson-baryon Lagrangian in charm quantum number one sector, the key ingredient in the present study, is adopted from a recent model by Hofmann and Lutz which has aimed at combining the charmed meson degree of freedom in a consistent manner with chiral unitary models. After a critical examination, the original model is modified in several important aspects, such as the method of regularization, in order to be more consistent and practical for our objective. The resultant interaction is used to reproduce the position and width of the s-wave \Lambda_c(2593) resonance in the isospin zero DN channel. In the isospin one channel, it generates a rather wide resonance at \~2770 MeV. The corresponding in-medium solution is then sought by incorporating Pauli blocking and the D- and \pi-meson dressing self-consistently. At normal nuclear matter density, the resultant \Lambda_c (2593) is found to stay narrow and shifted at a lower energy, while the I=1 resonance is lowered in position as well and broadened considerably. The possible implication of our findings on the J/\Psi suppression, etc. in relativistic heavy ion collisions is briefly discussed.
1509.00423
Juan Helo
J. C. Helo, M. Hirsch
LHC dijet constraints on double beta decay
13 pages, 5 figures
Phys. Rev. D 92, 073017 (2015)
10.1103/PhysRevD.92.073017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use LHC dijet data to derive constraints on neutrinoless double beta decay. Upper limits on cross sections for the production of "exotic" resonances, such as a right-handed W boson or a diquark, can be converted into lower limits on the double beta decay half-life for fixed choices of other parameters. Constraints derived from run-I data are already surprisingly strong and complementary to results from searches using same-sign dileptons plus jets. For the case of the left-right symmetric model, in case no new resonance is found in future runs of the LHC and assuming $g_L=g_R$, we estimate a lower limit on the double beta decay half-live larger than $10^{27}$ ys can be derived from future dijet data, except in the window of relatively light right-handed neutrino masses in the range $0.5$ MeV to $50$ GeV. Part of this mass window will be tested in the upcoming SHiP experiment. We also discuss current and future limits on possible scalar diquark contributions to double beta decay that can be derived from dijet data.
[ { "created": "Tue, 1 Sep 2015 18:18:09 GMT", "version": "v1" } ]
2015-11-04
[ [ "Helo", "J. C.", "" ], [ "Hirsch", "M.", "" ] ]
We use LHC dijet data to derive constraints on neutrinoless double beta decay. Upper limits on cross sections for the production of "exotic" resonances, such as a right-handed W boson or a diquark, can be converted into lower limits on the double beta decay half-life for fixed choices of other parameters. Constraints derived from run-I data are already surprisingly strong and complementary to results from searches using same-sign dileptons plus jets. For the case of the left-right symmetric model, in case no new resonance is found in future runs of the LHC and assuming $g_L=g_R$, we estimate a lower limit on the double beta decay half-live larger than $10^{27}$ ys can be derived from future dijet data, except in the window of relatively light right-handed neutrino masses in the range $0.5$ MeV to $50$ GeV. Part of this mass window will be tested in the upcoming SHiP experiment. We also discuss current and future limits on possible scalar diquark contributions to double beta decay that can be derived from dijet data.
hep-ph/0203195
Tuomas Multamaki
T. Multamaki, I. Vilja
Simulations of Q-Ball Formation
9 pages, 8 figures; corrected typos (v2,v3)
Phys.Lett. B535 (2002) 170-176
10.1016/S0370-2693(02)01730-6
TURKU-FL-P39-02
hep-ph
null
The fragmentation of the Affleck-Dine condensate is studied by utilizing 3+1 dimensional numerical simulations. The 3+1 dimensional simulations confirm that the fragmentation process is very similar to the results obtained by 2+1 dimensional simulations. We find, however, that the average size of Q-balls in 3+1 dimensions is somewhat larger that in 2+1 dimensions. A filament type structure in the charge density is observed during the fragmentation process. The resulting final Q-ball distribution is strongly dependent on the initial conditions of the condensate and approaches a thermal one as the energy-charge ratio of the Affleck-Dine condensate increases.
[ { "created": "Wed, 20 Mar 2002 10:56:48 GMT", "version": "v1" }, { "created": "Thu, 21 Mar 2002 12:38:26 GMT", "version": "v2" }, { "created": "Wed, 3 Apr 2002 06:35:56 GMT", "version": "v3" } ]
2009-11-07
[ [ "Multamaki", "T.", "" ], [ "Vilja", "I.", "" ] ]
The fragmentation of the Affleck-Dine condensate is studied by utilizing 3+1 dimensional numerical simulations. The 3+1 dimensional simulations confirm that the fragmentation process is very similar to the results obtained by 2+1 dimensional simulations. We find, however, that the average size of Q-balls in 3+1 dimensions is somewhat larger that in 2+1 dimensions. A filament type structure in the charge density is observed during the fragmentation process. The resulting final Q-ball distribution is strongly dependent on the initial conditions of the condensate and approaches a thermal one as the energy-charge ratio of the Affleck-Dine condensate increases.
1204.1337
Timothy Cohen
Timothy Cohen, Anson Hook, and Gonzalo Torroba
An Attractor for Natural Supersymmetry
22 pages, 4 figures; v2 refs added; v3 journal version
null
10.1103/PhysRevD.86.115005
SLAC-PUB-14924
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an attractor mechanism which generates the "more minimal" supersymmetric standard model from a broad class of supersymmetry breaking boundary conditions. The hierarchies in the fermion masses and mixings are produced by the same dynamics and a natural weak scale results from gaugino mediation. These features arise from augmenting the standard model with a new SU(3) gauge group under which only the third generation quarks are charged. The theory flows to a strongly interacting fixed point which induces a negative anomalous dimension for the third generation quarks and a positive anomalous dimension for the Higgs. As a result, a split-family natural spectrum and the flavor hierarchies are dynamically generated.
[ { "created": "Thu, 5 Apr 2012 20:00:00 GMT", "version": "v1" }, { "created": "Wed, 27 Jun 2012 18:03:18 GMT", "version": "v2" }, { "created": "Thu, 25 Oct 2012 23:06:55 GMT", "version": "v3" } ]
2013-05-30
[ [ "Cohen", "Timothy", "" ], [ "Hook", "Anson", "" ], [ "Torroba", "Gonzalo", "" ] ]
We propose an attractor mechanism which generates the "more minimal" supersymmetric standard model from a broad class of supersymmetry breaking boundary conditions. The hierarchies in the fermion masses and mixings are produced by the same dynamics and a natural weak scale results from gaugino mediation. These features arise from augmenting the standard model with a new SU(3) gauge group under which only the third generation quarks are charged. The theory flows to a strongly interacting fixed point which induces a negative anomalous dimension for the third generation quarks and a positive anomalous dimension for the Higgs. As a result, a split-family natural spectrum and the flavor hierarchies are dynamically generated.
0707.3202
Wolfgang Lucha
Z.-F. Li, Wolfgang Lucha, F. Schoberl
Stability in the instantaneous Bethe-Salpeter formalism: harmonic-oscillator reduced Salpeter equation
23 pages, 3 figures, extended conclusions, version to appear in Phys. Rev. D
Phys.Rev.D76:125028,2007
10.1103/PhysRevD.76.125028
HEPHY-PUB 843/07
hep-ph nucl-th
null
A popular three-dimensional reduction of the Bethe-Salpeter formalism for the description of bound states in quantum field theory is the Salpeter equation, derived by assuming both instantaneous interactions and free propagation of all bound-state constituents. Numerical (variational) studies of the Salpeter equation with confining interaction, however, observed specific instabilities of the solutions, likely related to the Klein paradox and rendering (part of the) bound states unstable. An analytic investigation of this problem by a comprehensive spectral analysis is feasible for the reduced Salpeter equation with only harmonic-oscillator confining interactions. There we are able to prove rigorously that the bound-state solutions correspond to real discrete energy spectra bounded from below and are thus free of any instabilities.
[ { "created": "Mon, 23 Jul 2007 06:22:25 GMT", "version": "v1" }, { "created": "Fri, 9 Nov 2007 09:52:01 GMT", "version": "v2" } ]
2008-11-26
[ [ "Li", "Z. -F.", "" ], [ "Lucha", "Wolfgang", "" ], [ "Schoberl", "F.", "" ] ]
A popular three-dimensional reduction of the Bethe-Salpeter formalism for the description of bound states in quantum field theory is the Salpeter equation, derived by assuming both instantaneous interactions and free propagation of all bound-state constituents. Numerical (variational) studies of the Salpeter equation with confining interaction, however, observed specific instabilities of the solutions, likely related to the Klein paradox and rendering (part of the) bound states unstable. An analytic investigation of this problem by a comprehensive spectral analysis is feasible for the reduced Salpeter equation with only harmonic-oscillator confining interactions. There we are able to prove rigorously that the bound-state solutions correspond to real discrete energy spectra bounded from below and are thus free of any instabilities.
hep-ph/0510034
Alan R. White
Alan. R. White
Sextet Quarks and the Pomeron at the LHC
6 pages, 3 figures, presented at the XIth Blois Conference on Elastic and Diffractive Scattering, Blois, France, May, 2005
null
null
null
hep-ph
null
Adding two color sextet quarks to QCD gives many special features. The high-energy S-Matrix, constructed via reggeon diagrams and chiral anomalies, contains the Critical Pomeron and electroweak symmetry breaking is produced, by sextet pions. Cosmic ray phenomena suggest large cross-section effects will be seen at the LHC, in particular, involving the pomeron. The sextet sector embeds, uniquely, in a massless, confining, left-handed SU(5) theory. The anomaly based high-energy S-Matrix could be that of the full Standard Model.
[ { "created": "Mon, 3 Oct 2005 19:56:00 GMT", "version": "v1" } ]
2016-09-06
[ [ "White", "Alan. R.", "" ] ]
Adding two color sextet quarks to QCD gives many special features. The high-energy S-Matrix, constructed via reggeon diagrams and chiral anomalies, contains the Critical Pomeron and electroweak symmetry breaking is produced, by sextet pions. Cosmic ray phenomena suggest large cross-section effects will be seen at the LHC, in particular, involving the pomeron. The sextet sector embeds, uniquely, in a massless, confining, left-handed SU(5) theory. The anomaly based high-energy S-Matrix could be that of the full Standard Model.
1006.2857
Danny Marfatia
Steve Blanchet, Danny Marfatia, Azar Mustafayev
Examining leptogenesis with lepton flavor violation and the dark matter abundance
20 pages, 5 figures, 1 table
JHEP 1011:038,2010
10.1007/JHEP11(2010)038
UMN-TH-2907/10, FTPI-MINN-10/15, UMD-PP-10-009
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within a supersymmetric (SUSY) type-I seesaw framework with flavor-blind universal boundary conditions, we study the consequences of requiring that the observed baryon asymmetry of the Universe be explained by either thermal or non-thermal leptogenesis. In the former case, we find that the parameter space is very constrained. In the bulk and stop-coannihilation regions of mSUGRA parameter space (that are consistent with the measured dark matter abundance), lepton flavor-violating (LFV) processes are accessible at MEG and future experiments. However, the very high reheat temperature of the Universe needed after inflation (of about 10^{12} GeV) leads to a severe gravitino problem, which disfavors either thermal leptogenesis or neutralino dark matter. Non-thermal leptogenesis in the preheating phase from SUSY flat directions relaxes the gravitino problem by lowering the required reheat temperature. The baryon asymmetry can then be explained while preserving neutralino dark matter, and for the bulk or stop-coannihilation regions LFV processes should be observed in current or future experiments.
[ { "created": "Mon, 14 Jun 2010 22:25:45 GMT", "version": "v1" } ]
2010-11-15
[ [ "Blanchet", "Steve", "" ], [ "Marfatia", "Danny", "" ], [ "Mustafayev", "Azar", "" ] ]
Within a supersymmetric (SUSY) type-I seesaw framework with flavor-blind universal boundary conditions, we study the consequences of requiring that the observed baryon asymmetry of the Universe be explained by either thermal or non-thermal leptogenesis. In the former case, we find that the parameter space is very constrained. In the bulk and stop-coannihilation regions of mSUGRA parameter space (that are consistent with the measured dark matter abundance), lepton flavor-violating (LFV) processes are accessible at MEG and future experiments. However, the very high reheat temperature of the Universe needed after inflation (of about 10^{12} GeV) leads to a severe gravitino problem, which disfavors either thermal leptogenesis or neutralino dark matter. Non-thermal leptogenesis in the preheating phase from SUSY flat directions relaxes the gravitino problem by lowering the required reheat temperature. The baryon asymmetry can then be explained while preserving neutralino dark matter, and for the bulk or stop-coannihilation regions LFV processes should be observed in current or future experiments.
0707.2944
Francois Arleo
Francois Arleo, Thierry Gousset
Measuring gluon shadowing with prompt photons at RHIC and LHC
14 pages, 6 figures. Typo corrected in Eq. (4)
Phys.Lett.B660:181-187,2008
10.1016/j.physletb.2007.12.025
CERN-PH-TH/2007-103, LAPTH-1202/07
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility to observe the nuclear modification of the gluon distribution at small-x (gluon shadowing) using high-p_T prompt photon production at RHIC and at LHC is discussed. The per-nucleon ratio, sigma(p+A -> gamma+X) / A sigma(p+p -> gamma+X), is computed for both inclusive and isolated prompt photons in perturbative QCD at NLO using different parametrizations of nuclear parton densities, in order to assess the visibility of the shadowing signal. The production of isolated photons turns out to be a promising channel which allows for a reliable extraction of the gluon density, G^A/G^p, and the structure function, F_2^A/F_2^p, in a nucleus over that in a proton. Moreover, the production ratio of prompt photons at forward-over-backward rapidity in p-A collisions provides an estimate of G^A/G^p (at small x) over F_2^A/F_2^p (at large x), without the need of p-p reference data at the same energy.
[ { "created": "Thu, 19 Jul 2007 17:31:24 GMT", "version": "v1" }, { "created": "Thu, 23 Oct 2008 12:20:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Arleo", "Francois", "" ], [ "Gousset", "Thierry", "" ] ]
The possibility to observe the nuclear modification of the gluon distribution at small-x (gluon shadowing) using high-p_T prompt photon production at RHIC and at LHC is discussed. The per-nucleon ratio, sigma(p+A -> gamma+X) / A sigma(p+p -> gamma+X), is computed for both inclusive and isolated prompt photons in perturbative QCD at NLO using different parametrizations of nuclear parton densities, in order to assess the visibility of the shadowing signal. The production of isolated photons turns out to be a promising channel which allows for a reliable extraction of the gluon density, G^A/G^p, and the structure function, F_2^A/F_2^p, in a nucleus over that in a proton. Moreover, the production ratio of prompt photons at forward-over-backward rapidity in p-A collisions provides an estimate of G^A/G^p (at small x) over F_2^A/F_2^p (at large x), without the need of p-p reference data at the same energy.
2101.11874
Zhen-Xing Zhao
Zhen-Xing Zhao, Xiao-Yu Sun, Fu-Wei Zhang, Zhi-Peng Xing
On the four-quark operator matrix elements for the lifetime of $\Lambda_{b}$
13 pages, 4 figures; version accepted by EPJC
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Heavy quark expansion can nicely explain the lifetime of $\Lambda_{b}$. However, there still exist sizable uncertainties from the four-quark operator matrix elements of $\Lambda_{b}$ in $1/m_{b}^{3}$ corrections, which describe the spectator effects. In this work, these four-quark operator matrix elements are investigated using full QCD sum rules for the first time. At the QCD level, contributions from up to dimension-6 four-quark operators are considered. Our method of calculating high-dimensional operator matrix elements is promising to be used to resolve the $\Omega_{c}$ lifetime puzzle.
[ { "created": "Thu, 28 Jan 2021 09:09:57 GMT", "version": "v1" }, { "created": "Thu, 6 Jul 2023 17:47:37 GMT", "version": "v2" }, { "created": "Sat, 2 Dec 2023 05:03:59 GMT", "version": "v3" } ]
2023-12-05
[ [ "Zhao", "Zhen-Xing", "" ], [ "Sun", "Xiao-Yu", "" ], [ "Zhang", "Fu-Wei", "" ], [ "Xing", "Zhi-Peng", "" ] ]
Heavy quark expansion can nicely explain the lifetime of $\Lambda_{b}$. However, there still exist sizable uncertainties from the four-quark operator matrix elements of $\Lambda_{b}$ in $1/m_{b}^{3}$ corrections, which describe the spectator effects. In this work, these four-quark operator matrix elements are investigated using full QCD sum rules for the first time. At the QCD level, contributions from up to dimension-6 four-quark operators are considered. Our method of calculating high-dimensional operator matrix elements is promising to be used to resolve the $\Omega_{c}$ lifetime puzzle.
2211.00422
Jean-Samuel Roux
James M. Cline, Benoit Laurent, Stuart Raby, Jean-Samuel Roux
PeV-scale leptogenesis, gravity waves and black holes from a SUSY-breaking phase transition
19 pages, 8 figures
null
10.1103/PhysRevD.107.095011
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Supersymmetry is a highly motivated theoretical framework, whose scale of breaking may be at PeV energies, to explain null searches at the Large Hadron Collider. SUSY breaking through a first order phase transition may have occurred in the early universe, leading to potential gravitational wave signals. Constructing a realistic model for gauge-mediated supersymmetry breaking, we show that such a transition can also induce masses for heavy right-handed neutrinos and sneutrinos, whose CP-violating decays give leptogenesis at the PeV scale, and a novel mechanism of neutrino mass generation at one loop. For the same models we predict the possible gravity wave signals, and we study the possibility of production of primordial black holes during the phase transition.
[ { "created": "Tue, 1 Nov 2022 12:32:27 GMT", "version": "v1" } ]
2023-05-17
[ [ "Cline", "James M.", "" ], [ "Laurent", "Benoit", "" ], [ "Raby", "Stuart", "" ], [ "Roux", "Jean-Samuel", "" ] ]
Supersymmetry is a highly motivated theoretical framework, whose scale of breaking may be at PeV energies, to explain null searches at the Large Hadron Collider. SUSY breaking through a first order phase transition may have occurred in the early universe, leading to potential gravitational wave signals. Constructing a realistic model for gauge-mediated supersymmetry breaking, we show that such a transition can also induce masses for heavy right-handed neutrinos and sneutrinos, whose CP-violating decays give leptogenesis at the PeV scale, and a novel mechanism of neutrino mass generation at one loop. For the same models we predict the possible gravity wave signals, and we study the possibility of production of primordial black holes during the phase transition.
hep-ph/0405162
Josip Trampetic Dr.
G. Duplancic, H. Pasagic, J. Trampetic
Rare $\Omega^{-} \to \Xi(1530)^{0} \pi^-$ decay in the Skyrme model
4 pages, version to appear in Phys. Rev. D
Phys.Rev. D70 (2004) 077506
10.1103/PhysRevD.70.077506
null
hep-ph
null
Rare nonleptonic $\Omega^{-} \to \Xi(1530)^{0} \pi^-$ decay branching ratio is estimated by means of the QCD enhanced effective weak Hamiltonian supplemented by the SU(3) Skyrme model used to estimate the nonperturbative matrix elements. The whole scheme is equivalent to that which works well for the nonleptonic hyperon and $\Omega^{-}$ decays. The computed rate is in a good agreement with data.
[ { "created": "Tue, 18 May 2004 09:26:48 GMT", "version": "v1" }, { "created": "Fri, 21 May 2004 17:14:04 GMT", "version": "v2" }, { "created": "Wed, 13 Oct 2004 15:43:26 GMT", "version": "v3" } ]
2009-11-10
[ [ "Duplancic", "G.", "" ], [ "Pasagic", "H.", "" ], [ "Trampetic", "J.", "" ] ]
Rare nonleptonic $\Omega^{-} \to \Xi(1530)^{0} \pi^-$ decay branching ratio is estimated by means of the QCD enhanced effective weak Hamiltonian supplemented by the SU(3) Skyrme model used to estimate the nonperturbative matrix elements. The whole scheme is equivalent to that which works well for the nonleptonic hyperon and $\Omega^{-}$ decays. The computed rate is in a good agreement with data.
0812.0524
Sven Heinemeyer
S. Heinemeyer, A. Nikitenko, G. Weiglein
Charged MSSM Higgs Bosons at CMS: Reach and Parameter Dependence
6 pages, 3 figures. Talk given at the "cHarged 2008", Uppsala, Sweden, September 2008
null
null
DCPT/08/178, IPPP/08/89
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the analysis of the 5 sigma discovery contours for the charged MSSM Higgs boson at the CMS experiment with 30 fb^-1 for the two cases M_H+ < m_t and M_H+ > m_t. Latest results for the CMS experimental sensitivities based on full simulation studies are combined with state-of-the-art theoretical predictions of MSSM Higgs-boson production and decay properties. Special focus is put on the SUSY parameter dependence of the 5 sigma contours. The variation of mu can shift the prospective discovery reach in tan_beta by up to Delta tan_beta = 40. We furthermore discuss various theory uncertainties on the signal cross section and branching ratio calculations. In order to arrive at a reliable interpretation of a signal of the charged MSSM Higgs boson at the LHC a strong reduction in the relevant theory uncertainties will be necessary.
[ { "created": "Tue, 2 Dec 2008 15:04:26 GMT", "version": "v1" } ]
2008-12-03
[ [ "Heinemeyer", "S.", "" ], [ "Nikitenko", "A.", "" ], [ "Weiglein", "G.", "" ] ]
We review the analysis of the 5 sigma discovery contours for the charged MSSM Higgs boson at the CMS experiment with 30 fb^-1 for the two cases M_H+ < m_t and M_H+ > m_t. Latest results for the CMS experimental sensitivities based on full simulation studies are combined with state-of-the-art theoretical predictions of MSSM Higgs-boson production and decay properties. Special focus is put on the SUSY parameter dependence of the 5 sigma contours. The variation of mu can shift the prospective discovery reach in tan_beta by up to Delta tan_beta = 40. We furthermore discuss various theory uncertainties on the signal cross section and branching ratio calculations. In order to arrive at a reliable interpretation of a signal of the charged MSSM Higgs boson at the LHC a strong reduction in the relevant theory uncertainties will be necessary.
1504.06643
Mathias Garny
Mathias Garny, Urko Reinosa
Renormalization out of equilibrium in a superrenormalizable theory
5 pages, 2 figures
Phys. Rev. D 94, 045012 (2016)
10.1103/PhysRevD.94.045012
CERN-PH-TH-2015-095, CPHT-RR014.0415
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the renormalization of the initial value problem in Nonequilibrium Quantum Field Theory within a simple, yet instructive, example and show how to obtain a renormalized time evolution for the two-point functions of a scalar field and its conjugate momentum at all times. The scheme we propose is applicable to systems that are initially far from equilibrium and compatible with non-secular approximation schemes which capture thermalization. It is based on Kadanoff-Baym equations for non-Gaussian initial states, complemented by usual vacuum counterterms. We explicitly demonstrate how various cutoff-dependent effects peculiar to nonequilibrium systems, including time-dependent divergences or initial-time singularities, are avoided by taking an initial non-Gaussian three-point vacuum correlation into account.
[ { "created": "Fri, 24 Apr 2015 21:05:00 GMT", "version": "v1" } ]
2016-08-31
[ [ "Garny", "Mathias", "" ], [ "Reinosa", "Urko", "" ] ]
We discuss the renormalization of the initial value problem in Nonequilibrium Quantum Field Theory within a simple, yet instructive, example and show how to obtain a renormalized time evolution for the two-point functions of a scalar field and its conjugate momentum at all times. The scheme we propose is applicable to systems that are initially far from equilibrium and compatible with non-secular approximation schemes which capture thermalization. It is based on Kadanoff-Baym equations for non-Gaussian initial states, complemented by usual vacuum counterterms. We explicitly demonstrate how various cutoff-dependent effects peculiar to nonequilibrium systems, including time-dependent divergences or initial-time singularities, are avoided by taking an initial non-Gaussian three-point vacuum correlation into account.
hep-ph/9206231
Ernest Ma
Ernest Ma
Accidental Approximate Generation Universality and its Possible Verification
6 pages (2 figures, not included)
Proc. of Beyond the Standard Model III, p.485 (1993)
null
UCRHEP-T93 (June 1992)
hep-ph
null
The universality of $e-\mu-\tau$ interactions may only be an accidental approximate symmetry analogous to that of flavor SU(2) and SU(3). This was specifically realized by an extension of the standard model proposed in 1981. Two key predictions are that the $\tau$ lifetime should be longer and that the $\rho$ parameter measured at the Z peak should have an additional negative contribution. These are consistent with present precision electroweak measurements. A future decisive test of this model would be the discovery of new W and Z bosons with nearly degenerate masses of a few TeV.
[ { "created": "Wed, 17 Jun 1992 20:26:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ma", "Ernest", "" ] ]
The universality of $e-\mu-\tau$ interactions may only be an accidental approximate symmetry analogous to that of flavor SU(2) and SU(3). This was specifically realized by an extension of the standard model proposed in 1981. Two key predictions are that the $\tau$ lifetime should be longer and that the $\rho$ parameter measured at the Z peak should have an additional negative contribution. These are consistent with present precision electroweak measurements. A future decisive test of this model would be the discovery of new W and Z bosons with nearly degenerate masses of a few TeV.
1707.00988
Stefan de Boer
Stefan de Boer
Two loop virtual corrections to $b\to(d,s)\ell^+\ell^-$ and $c\to u\ell^+\ell^-$ for arbitrary momentum transfer
14 pages plus references and appendix. The results are supplemented to the source files of this paper; v2: typos corrected and clarifications and references added, supplemented files (+ analytical results in terms of GPLs) and description thereof improved, results unchanged; v3: files and text (fitted results for negative momentum transfer and factorizable results) added, results unchanged
null
10.1140/epjc/s10052-017-5364-x
DO-TH 17/06, QFET-2017-14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-factorizable two loop corrections to heavy to light flavor changing neutral current transitions due to matrix elements of current-current operators are calculated analytically for arbitrary momentum transfer. This extends previous works on $b\to(d,s)\ell^+\ell^-$ transitions. New results for $c\to u\ell^+\ell^-$ transitions are presented. Recent works on polylogarithms are used for the master integrals. For $b\to s\ell^+\ell^-$ transitions, the corrections are most significant for the imaginary parts of the effective Wilson coefficients in the large hadronic recoil range. Analytical results and ready-to-use fitted results for a specific set of parameters are provided.
[ { "created": "Tue, 4 Jul 2017 13:47:47 GMT", "version": "v1" }, { "created": "Thu, 2 Nov 2017 14:50:14 GMT", "version": "v2" }, { "created": "Wed, 23 Jan 2019 16:54:34 GMT", "version": "v3" } ]
2019-01-24
[ [ "de Boer", "Stefan", "" ] ]
Non-factorizable two loop corrections to heavy to light flavor changing neutral current transitions due to matrix elements of current-current operators are calculated analytically for arbitrary momentum transfer. This extends previous works on $b\to(d,s)\ell^+\ell^-$ transitions. New results for $c\to u\ell^+\ell^-$ transitions are presented. Recent works on polylogarithms are used for the master integrals. For $b\to s\ell^+\ell^-$ transitions, the corrections are most significant for the imaginary parts of the effective Wilson coefficients in the large hadronic recoil range. Analytical results and ready-to-use fitted results for a specific set of parameters are provided.
hep-ph/0112047
Marek Karliner
Marek Karliner (Tel-Aviv U.)
Towards the resolution of the e+e- --> Nbar N puzzle
Invited talk at the Int. Workshop "Light-cone Physics: Particles and Strings", Trento, Sept. 3-11, 2001
Nucl.Phys.Proc.Suppl. 108 (2002) 84-90
10.1016/S0920-5632(02)01309-9
TAUP-2693-01
hep-ph
null
We discuss the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to the threshold, in particular the fact that sigma(e+e- --> nbar n) is somewhat greater than sigma(e+e- --> pbar p). We discuss an interpretation in terms of a two-step process, via an intermediate coherent isovector state serving as an intermediary between e+e- and the baryon-antibaryon system. We provide evidence that the isovector channel dominates both e+e- --> pions and from Nbar N annihilation at rest, and show that the observed ratio of sigma(e+e- --> nbar n)/sigma(e+e- --> pbar p) can be understood quantitatively in this picture.
[ { "created": "Tue, 4 Dec 2001 11:26:41 GMT", "version": "v1" } ]
2009-11-07
[ [ "Karliner", "Marek", "", "Tel-Aviv U." ] ]
We discuss the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to the threshold, in particular the fact that sigma(e+e- --> nbar n) is somewhat greater than sigma(e+e- --> pbar p). We discuss an interpretation in terms of a two-step process, via an intermediate coherent isovector state serving as an intermediary between e+e- and the baryon-antibaryon system. We provide evidence that the isovector channel dominates both e+e- --> pions and from Nbar N annihilation at rest, and show that the observed ratio of sigma(e+e- --> nbar n)/sigma(e+e- --> pbar p) can be understood quantitatively in this picture.
1902.08212
Abhishek Banerjee
Abhishek Banerjee, Dmitry Budker, Joshua Eby, Hyungjin Kim, and Gilad Perez
Relaxion Stars and their detection via Atomic Physics
17 pages, 6 figures; v2: minor revisions, matches published version
Commun Phys 3, 1 (2020)
10.1038/s42005-019-0260-3
null
hep-ph astro-ph.CO physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cosmological relaxion can address the hierarchy problem, while its coherent oscillations can constitute dark matter in the present universe. We consider the possibility that the relaxion forms gravitationally bound objects that we denote as relaxion stars. The density of these stars would be higher than that of the local dark matter density, resulting in enhanced signals in table-top detectors, among others. Furthermore, we raise the possibility that these objects may be trapped by an external gravitational potential, such as that of the Earth or the Sun. This leads to formation of relaxion halos of even greater density. We discuss several interesting implications of relaxion halos, as well as detection strategies to probe them.
[ { "created": "Thu, 21 Feb 2019 19:00:06 GMT", "version": "v1" }, { "created": "Wed, 27 Nov 2019 11:46:14 GMT", "version": "v2" } ]
2020-01-14
[ [ "Banerjee", "Abhishek", "" ], [ "Budker", "Dmitry", "" ], [ "Eby", "Joshua", "" ], [ "Kim", "Hyungjin", "" ], [ "Perez", "Gilad", "" ] ]
The cosmological relaxion can address the hierarchy problem, while its coherent oscillations can constitute dark matter in the present universe. We consider the possibility that the relaxion forms gravitationally bound objects that we denote as relaxion stars. The density of these stars would be higher than that of the local dark matter density, resulting in enhanced signals in table-top detectors, among others. Furthermore, we raise the possibility that these objects may be trapped by an external gravitational potential, such as that of the Earth or the Sun. This leads to formation of relaxion halos of even greater density. We discuss several interesting implications of relaxion halos, as well as detection strategies to probe them.
1210.3439
Jeonghyeon Song
Sanghyeon Chang, Sin Kyu Kang, Jong-Phil Lee, Kang Young Lee, Seong Chan Park, Jeonghyeon Song
Comprehensive study of two Higgs doublet model in light of the new boson with mass around 125 GeV
References are added with 18 pages, 2 figures, 4 tables
null
10.1007/JHEP05(2013)075
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent discovery of a new boson of mass roughly 125 GeV has been reported by the ATLAS and CMS collaborations. Although its signals in various decay modes resemble those of the standard model (SM) Higgs boson, observed are the combinations of entangled information about the production, decay rates and total decay width of the new boson. In addition, some decay channels show non-negligible deviation from the SM expectation, such as the $2\sigma$ excess in the diphoton channel. In the four types (I, II, X and Y) of two Higgs doublet models, we perform the global $\chi^2$ fit in three scenarios: (i) the new boson is the light CP-even Higgs boson $h^0$; (ii) it is the heavy CP-even Higgs boson $H^0$; (iii) the signals are from degenerate $h^0$ and the pseudoscalar $A^0$. Considering other phenomenological constraints such as flavor physics, electroweak precision data, and the LEP search for the Higgs boson, we find that the the first scenarios in Type II and Type Y models actually provide better or similarly good fit to the data than the SM. All the other models are excluded at 95% C.L..
[ { "created": "Fri, 12 Oct 2012 06:45:19 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2012 09:11:53 GMT", "version": "v2" } ]
2015-06-11
[ [ "Chang", "Sanghyeon", "" ], [ "Kang", "Sin Kyu", "" ], [ "Lee", "Jong-Phil", "" ], [ "Lee", "Kang Young", "" ], [ "Park", "Seong Chan", "" ], [ "Song", "Jeonghyeon", "" ] ]
The recent discovery of a new boson of mass roughly 125 GeV has been reported by the ATLAS and CMS collaborations. Although its signals in various decay modes resemble those of the standard model (SM) Higgs boson, observed are the combinations of entangled information about the production, decay rates and total decay width of the new boson. In addition, some decay channels show non-negligible deviation from the SM expectation, such as the $2\sigma$ excess in the diphoton channel. In the four types (I, II, X and Y) of two Higgs doublet models, we perform the global $\chi^2$ fit in three scenarios: (i) the new boson is the light CP-even Higgs boson $h^0$; (ii) it is the heavy CP-even Higgs boson $H^0$; (iii) the signals are from degenerate $h^0$ and the pseudoscalar $A^0$. Considering other phenomenological constraints such as flavor physics, electroweak precision data, and the LEP search for the Higgs boson, we find that the the first scenarios in Type II and Type Y models actually provide better or similarly good fit to the data than the SM. All the other models are excluded at 95% C.L..
1504.02729
Shun Zhou
Shun Zhou
Supernova Bounds on keV-mass Sterile Neutrinos
10 pages, 2 figures, to be published in the Proceedings of International Conference on Massive Neutrinos, Singapore, February 9-13, 2015. arXiv admin note: text overlap with arXiv:1109.3187
null
10.1142/S0217751X15300331
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sterile neutrinos of keV masses are one of the most promising candidates for the warm dark matter, which could solve the small-scale problems encountered in the scenario of cold dark matter. We present a detailed study of the production of such sterile neutrinos in a supernova core, and derive stringent bounds on the active-sterile neutrino mixing angles and sterile neutrino masses based on the standard energy-loss argument.
[ { "created": "Fri, 10 Apr 2015 16:12:15 GMT", "version": "v1" } ]
2015-05-20
[ [ "Zhou", "Shun", "" ] ]
Sterile neutrinos of keV masses are one of the most promising candidates for the warm dark matter, which could solve the small-scale problems encountered in the scenario of cold dark matter. We present a detailed study of the production of such sterile neutrinos in a supernova core, and derive stringent bounds on the active-sterile neutrino mixing angles and sterile neutrino masses based on the standard energy-loss argument.
hep-ph/9805359
Sergio Lupia
Sergio Lupia (Max-Planck-Inst. fuer Physik, Munich)
QCD description of high order factorial moments in quark and gluon jets
LaTeX, 3 pages, to appear in Proc. of XXXIIIrd Rencontres de Moriond, `QCD and high energy interactions'', Les Arcs, France, March 21-28, 1998
null
null
MPI-PhT/98-37
hep-ph
null
The complete QCD evolution equation for factorial moments in quark and gluon jets is numerically solved with initial conditions at threshold by fully taking into account the energy-momentum conservation law. Within the picture of Local Parton Hadron Duality, the perturbative QCD predictions can successfully describe the available experimental data.
[ { "created": "Mon, 18 May 1998 13:57:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lupia", "Sergio", "", "Max-Planck-Inst. fuer Physik, Munich" ] ]
The complete QCD evolution equation for factorial moments in quark and gluon jets is numerically solved with initial conditions at threshold by fully taking into account the energy-momentum conservation law. Within the picture of Local Parton Hadron Duality, the perturbative QCD predictions can successfully describe the available experimental data.
hep-ph/0412241
Matthias Neubert
Matthias Neubert (Cornell University & IAS, Princeton)
Two-Loop Relations for Heavy-Quark Parameters in the Shape-Function Scheme
10 pages, 1 figure. Two-loop shape-function anomalous dimension corrected; minor numerical changes. Version to appear in Physics Letters B
Phys.Lett. B612 (2005) 13-20
10.1016/j.physletb.2005.02.055
CLNS-04/1903
hep-ph
null
Moments of the renormalized B-meson shape function provide a natural way to define short-distance, running heavy-quark parameters such as the b-quark mass and kinetic energy. These parameters are particularly well suited for studies of inclusive decay distributions. The definitions of m_b and mu_pi^2 in this ``shape-function scheme'' are derived to two-loop order. Using previous determinations of heavy-quark parameters in other schemes, we find m_b=(4.63+-0.08) GeV and mu_\pi^2=(0.15+-0.07) GeV^2 at a reference scale of 1.5 GeV.
[ { "created": "Thu, 16 Dec 2004 21:03:30 GMT", "version": "v1" }, { "created": "Fri, 4 Mar 2005 20:58:08 GMT", "version": "v2" } ]
2010-04-05
[ [ "Neubert", "Matthias", "", "Cornell University & IAS, Princeton" ] ]
Moments of the renormalized B-meson shape function provide a natural way to define short-distance, running heavy-quark parameters such as the b-quark mass and kinetic energy. These parameters are particularly well suited for studies of inclusive decay distributions. The definitions of m_b and mu_pi^2 in this ``shape-function scheme'' are derived to two-loop order. Using previous determinations of heavy-quark parameters in other schemes, we find m_b=(4.63+-0.08) GeV and mu_\pi^2=(0.15+-0.07) GeV^2 at a reference scale of 1.5 GeV.
0712.1711
D. P. Roy
M. Hirsch, D. P. Roy and J. W. F. Valle
Probing a Supersymmetric Model for Neutrino Masses at Ultrahigh Energy Neutrino Telescopes
11 pages pdf including 2 figures. Discussion added. Final version to appear in Physics Letters B
Phys.Lett.B662:185-189,2008
10.1016/j.physletb.2008.02.065
IFIC/07-76
hep-ph
null
A bilinear R-Parity breaking SUSY model for neutrino mass and mixing predicts the lightest superparticle to decay mainly into a pair of tau leptons or b quarks along with a neutrino for relatively light SUSY spectra. This leads to a distinctive triple bang signature of SUSY events at ultrahigh energy neutrino telescopes like IceCube or Antares. While the expected signal size is only marginal at IceCube, it will be promising for a future multi-km^3 size neutrino telescope.
[ { "created": "Tue, 11 Dec 2007 13:47:13 GMT", "version": "v1" }, { "created": "Thu, 28 Feb 2008 16:17:16 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hirsch", "M.", "" ], [ "Roy", "D. P.", "" ], [ "Valle", "J. W. F.", "" ] ]
A bilinear R-Parity breaking SUSY model for neutrino mass and mixing predicts the lightest superparticle to decay mainly into a pair of tau leptons or b quarks along with a neutrino for relatively light SUSY spectra. This leads to a distinctive triple bang signature of SUSY events at ultrahigh energy neutrino telescopes like IceCube or Antares. While the expected signal size is only marginal at IceCube, it will be promising for a future multi-km^3 size neutrino telescope.
0901.3673
Leonid Slad
L.M. Slad
Electromagnetic form factors and polarizations of non-Dirac particles with rest spin 1/2
14 pages, no figures
Theor.Math.Phys.158:112-124,2009; Teor.Mat.Fiz.158:135-149,2009
10.1007/s11232-009-0009-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider one aspect of the theoretical foundations of polarization experiments on elastic scattering of electrons on protons yielding form factor ratios incompatible with those that are extracted from nonpolarization experiments. We analyze the consequences of abandoning the assumption that the nucleon is a Dirac particle. We show that the process of elastic scattering of electrons on nucleons is described by the same formulas, irrespective of the proper Lorentz group representation associated with the nucleon as a particle with the rest spin 1/2.
[ { "created": "Fri, 23 Jan 2009 14:03:27 GMT", "version": "v1" } ]
2010-04-21
[ [ "Slad", "L. M.", "" ] ]
We consider one aspect of the theoretical foundations of polarization experiments on elastic scattering of electrons on protons yielding form factor ratios incompatible with those that are extracted from nonpolarization experiments. We analyze the consequences of abandoning the assumption that the nucleon is a Dirac particle. We show that the process of elastic scattering of electrons on nucleons is described by the same formulas, irrespective of the proper Lorentz group representation associated with the nucleon as a particle with the rest spin 1/2.
hep-ph/0312279
O. Nachtmann
Otto Nachtmann
Pomeron Physics and QCD
15 pages, Contribution to the Ringberg Workshop on HERA Physics 2003
null
10.1142/9789812702722_0023
HD-THEP-03-63
hep-ph
null
We review some theoretical ideas concerning diffractive processes. We discuss the Regge Ansatz for the pomeron and the two pomeron model. Then we present the results obtained from nonperturbative QCD for high energy scattering. There we can extract from elastic scattering data the parameters describing the QCD vacuum, in particular the string tension.
[ { "created": "Fri, 19 Dec 2003 14:21:19 GMT", "version": "v1" } ]
2017-08-23
[ [ "Nachtmann", "Otto", "" ] ]
We review some theoretical ideas concerning diffractive processes. We discuss the Regge Ansatz for the pomeron and the two pomeron model. Then we present the results obtained from nonperturbative QCD for high energy scattering. There we can extract from elastic scattering data the parameters describing the QCD vacuum, in particular the string tension.
1507.04281
Howard E. Haber
Howard E. Haber and Oscar Stal
New LHC Benchmarks for the CP-conserving Two-Higgs-Doublet Model
38 pages, 16 figures, 11 tables. Typographical errors corrected, a clarifying remark added to the caption of Fig. 2, and two references updated in Version 4
Eur.Phys. J. C75 (2015) 491
10.1140/epjc/s10052-015-3697-x
SCIPP-15/10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a strategy to study the parameter space of the general, CP-conserving, two-Higgs-doublet Model (2HDM) with a softly broken Z_2-symmetry by means of a new "hybrid" basis. In this basis the input parameters are the measured values of the mass of the observed Standard Model (SM)-like Higgs boson and its coupling strength to vector boson pairs, the mass of the second CP-even Higgs boson, the ratio of neutral Higgs vacuum expectation values, and three additional dimensionless parameters. Using the hybrid basis, we present numerical scans of the 2HDM parameter space where we survey available parameter regions and analyze model constraints. From these results, we define a number of benchmark scenarios that capture different aspects of non-standard Higgs phenomenology that are of interest for future LHC Higgs searches.
[ { "created": "Wed, 15 Jul 2015 16:23:15 GMT", "version": "v1" }, { "created": "Wed, 22 Jul 2015 03:59:04 GMT", "version": "v2" }, { "created": "Thu, 27 Aug 2015 16:53:52 GMT", "version": "v3" }, { "created": "Tue, 17 May 2016 06:06:24 GMT", "version": "v4" } ]
2016-05-18
[ [ "Haber", "Howard E.", "" ], [ "Stal", "Oscar", "" ] ]
We introduce a strategy to study the parameter space of the general, CP-conserving, two-Higgs-doublet Model (2HDM) with a softly broken Z_2-symmetry by means of a new "hybrid" basis. In this basis the input parameters are the measured values of the mass of the observed Standard Model (SM)-like Higgs boson and its coupling strength to vector boson pairs, the mass of the second CP-even Higgs boson, the ratio of neutral Higgs vacuum expectation values, and three additional dimensionless parameters. Using the hybrid basis, we present numerical scans of the 2HDM parameter space where we survey available parameter regions and analyze model constraints. From these results, we define a number of benchmark scenarios that capture different aspects of non-standard Higgs phenomenology that are of interest for future LHC Higgs searches.
1309.4447
John Kearney
John Kearney and Aaron Pierce
Dark Sector Mass Relations from RG Focusing
10 pages, 7 figures; v2: LHC projections in figure 1 slightly modified, conclusions unchanged
Phys. Rev. D 88, 095009 (2013)
10.1103/PhysRevD.88.095009
MCTP-13-26
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark sector mass relations, such as those which permit near-threshold or near-resonance annihilation in the early universe, could arise due to IR-attractive ratios in renormalization group equations. Achieving a particular ratio requires specific dark matter gauge charges or interactions, leading to predictions about the dark matter properties. Furthermore, additional states with masses comparable to the dark matter mass may be necessary, potentially giving rise to novel phenomenology. We explore this idea in the context of dark matter charged under a new gauged $U(1)_X$ that kinetically mixes with the Standard Model hypercharge.
[ { "created": "Tue, 17 Sep 2013 20:00:00 GMT", "version": "v1" }, { "created": "Tue, 12 Nov 2013 20:54:36 GMT", "version": "v2" } ]
2013-11-20
[ [ "Kearney", "John", "" ], [ "Pierce", "Aaron", "" ] ]
Dark sector mass relations, such as those which permit near-threshold or near-resonance annihilation in the early universe, could arise due to IR-attractive ratios in renormalization group equations. Achieving a particular ratio requires specific dark matter gauge charges or interactions, leading to predictions about the dark matter properties. Furthermore, additional states with masses comparable to the dark matter mass may be necessary, potentially giving rise to novel phenomenology. We explore this idea in the context of dark matter charged under a new gauged $U(1)_X$ that kinetically mixes with the Standard Model hypercharge.
2212.12227
Xu Li
Xu Li
Positivity bounds at one-loop level: the Higgs sector
23 papers, 3 figures
null
10.1007/JHEP05(2023)230
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we promote the convex cone method of positive bounds from tree level to loop level. This method is general and can be applied to obtain leading $s^2$ positivity bounds on the forward scattering process in the standard model effective field theory. To obtain the loop level bounds, the original tree level bounds are modified by loop corrections, which involve low dimensional coefficients. New positivity bounds being valid at one loop level on the four-Higgs scattering have been provided. We study some specific ultraviolet models to check the validity of the new bounds. In addition, the renormalisation group effect on positivity is explored. We point out that as long as the new bounds are satisfied at the cutoff scale $\Lambda$, they will also be satisfied at all scales.
[ { "created": "Fri, 23 Dec 2022 09:42:50 GMT", "version": "v1" }, { "created": "Wed, 17 May 2023 03:02:50 GMT", "version": "v2" } ]
2023-06-14
[ [ "Li", "Xu", "" ] ]
In this paper, we promote the convex cone method of positive bounds from tree level to loop level. This method is general and can be applied to obtain leading $s^2$ positivity bounds on the forward scattering process in the standard model effective field theory. To obtain the loop level bounds, the original tree level bounds are modified by loop corrections, which involve low dimensional coefficients. New positivity bounds being valid at one loop level on the four-Higgs scattering have been provided. We study some specific ultraviolet models to check the validity of the new bounds. In addition, the renormalisation group effect on positivity is explored. We point out that as long as the new bounds are satisfied at the cutoff scale $\Lambda$, they will also be satisfied at all scales.
0806.4386
Ernest Ma
Ernest Ma (UC Riverside)
Axionic Extensions of the Supersymmetric Standard Model
12 pages, 1 figure
null
10.1142/S0217732309030837
UCRHEP-T452 (June 2008)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Supersymmetric Standard Model is a benchmark theoretical framework for particle physics, yet it suffers from a number of deficiencies, chief among which is the strong CP problem. Solving this with an axion in the context of selected new particles, it is shown in three examples that other problems go away automatically as well, resulting in (-)^L and (-)^{3B} conservation, viable combination of two dark-matter candidates, successful baryogenesis, seesaw neutrino masses, and verifiable experimental consequences at the TeV energy scale.
[ { "created": "Thu, 26 Jun 2008 20:07:45 GMT", "version": "v1" } ]
2015-05-13
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
The Supersymmetric Standard Model is a benchmark theoretical framework for particle physics, yet it suffers from a number of deficiencies, chief among which is the strong CP problem. Solving this with an axion in the context of selected new particles, it is shown in three examples that other problems go away automatically as well, resulting in (-)^L and (-)^{3B} conservation, viable combination of two dark-matter candidates, successful baryogenesis, seesaw neutrino masses, and verifiable experimental consequences at the TeV energy scale.
1302.3710
Thorsten Renk
Thorsten Renk
The Physics probed by the P_T Dependence of the Nuclear Suppression Factor
7 pages, 4 figures
null
10.1103/PhysRevC.88.014905
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The nuclear suppression factor R_AA of single inclusive hadrons measured in ultrarelativistic heavy-ion collisions was the first observable to study jet quenching, i.e. the final state interaction of hard parton showers with the surrounding bulk matter. While its transverse momentum (P_T) dependence of R_AA observed at RHIC was weak and hence never decisive in constraining models, there is now a strong and non-trivial P_T dependence observed at the LHC. This has been a challenge for several models which worked well at RHIC kinematics. However, in more general terms it is also of importance to understand what physical properties of the hard process and the parton-medium interaction are reflected in R_AA(P_T). The results of the work presented here suggest that the two main effects underlying the P_T dependence are the Quantum-Chromodynamics scale evolution of the fragmentation function and the limited distance (set by the typical medium length scale) for which a shower evolves in the medium.
[ { "created": "Fri, 15 Feb 2013 09:55:08 GMT", "version": "v1" } ]
2013-08-09
[ [ "Renk", "Thorsten", "" ] ]
The nuclear suppression factor R_AA of single inclusive hadrons measured in ultrarelativistic heavy-ion collisions was the first observable to study jet quenching, i.e. the final state interaction of hard parton showers with the surrounding bulk matter. While its transverse momentum (P_T) dependence of R_AA observed at RHIC was weak and hence never decisive in constraining models, there is now a strong and non-trivial P_T dependence observed at the LHC. This has been a challenge for several models which worked well at RHIC kinematics. However, in more general terms it is also of importance to understand what physical properties of the hard process and the parton-medium interaction are reflected in R_AA(P_T). The results of the work presented here suggest that the two main effects underlying the P_T dependence are the Quantum-Chromodynamics scale evolution of the fragmentation function and the limited distance (set by the typical medium length scale) for which a shower evolves in the medium.
hep-ph/0108113
Matthew Martin
Daniel Boyanovsky, Hector J. de Vega, Richard Holman, Matthew R. Martin
Non-Equilibrium Large N Yukawa Dynamics: marching through the Landau pole
36 pages, 14 figures, LaTeX, submitted to Physical Review D
Phys.Rev.D65:045007,2002
10.1103/PhysRevD.65.045007
null
hep-ph astro-ph hep-th
null
The non-equilibrium dynamics of a Yukawa theory with N fermions coupled to a scalar field is studied in the large N limit with the goal of comparing the dynamics predicted from the renormalization group improved effective potential to that obtained including the fermionic backreaction. The effective potential is of the Coleman-Weinberg type. Its renormalization group improvement is unbounded from below and features a Landau pole. When viewed self-consistently, the initial time singularity does not arise. The different regimes of the dynamics of the fully renormalized theory are studied both analytically and numerically. Despite the existence of a Landau pole in the model, the dynamics of the mean field is smooth as it passes the location of the pole. This is a consequence of a remarkable cancellation between the effective potential and the dynamical chiral condensate. The asymptotic evolution is effectively described by a quartic upright effective potential. In all regimes, profuse particle production results in the formation of a dense fermionic plasma with occupation numbers nearly saturated up to a scale of the order of the mean field. This can be interpreted as a chemical potential. We discuss the implications of these results for cosmological preheating.
[ { "created": "Mon, 13 Aug 2001 20:09:58 GMT", "version": "v1" } ]
2014-11-17
[ [ "Boyanovsky", "Daniel", "" ], [ "de Vega", "Hector J.", "" ], [ "Holman", "Richard", "" ], [ "Martin", "Matthew R.", "" ] ]
The non-equilibrium dynamics of a Yukawa theory with N fermions coupled to a scalar field is studied in the large N limit with the goal of comparing the dynamics predicted from the renormalization group improved effective potential to that obtained including the fermionic backreaction. The effective potential is of the Coleman-Weinberg type. Its renormalization group improvement is unbounded from below and features a Landau pole. When viewed self-consistently, the initial time singularity does not arise. The different regimes of the dynamics of the fully renormalized theory are studied both analytically and numerically. Despite the existence of a Landau pole in the model, the dynamics of the mean field is smooth as it passes the location of the pole. This is a consequence of a remarkable cancellation between the effective potential and the dynamical chiral condensate. The asymptotic evolution is effectively described by a quartic upright effective potential. In all regimes, profuse particle production results in the formation of a dense fermionic plasma with occupation numbers nearly saturated up to a scale of the order of the mean field. This can be interpreted as a chemical potential. We discuss the implications of these results for cosmological preheating.
hep-ph/0003087
Pene
A. Le Yaouanc, D. Melikhov, V. Mor\'enas, L. Oliver, O. P\`ene, and J.-C. Raynal
One Interesting New Sum Rule Extending Bjorken's to order {1/m_Q}
9 pages
Phys.Lett. B480 (2000) 119-128
10.1016/S0370-2693(00)00383-X
LPT-ORSAY 00/27, HD-THEP-00-12, PCCF RI 0005
hep-ph
null
We explicitly check quark-hadron duality to order $(m_b-m_c)\Lambda/m_b^2$ for $b \to c l\nu$ decays in the limit $m_b-m_c \ll m_b$ including ground state and orbitally excited hadrons. Duality occurs thanks to a new sum rule which expresses the subleading HQET form factor $\xi_3$ or, in other notations, $a_+^{(1)}$ in terms of the infinite mass limit form factors and some level splittings. We also demonstrate the sum rule, which is not restricted to the condition $m_b-m_c \ll m_b$, applying OPE to the longitudinal axial component of the hadronic tensor without neglecting the $1/m_b$ subleading contributions to the form factors. We argue that this method should produce a new class of sum rules, depending on the current, beyond Bjorken, Voloshin and the known tower of higher moments. Applying OPE to the vector currents we find another derivation of the Voloshin sum rule. From independent results on $\xi_3$ we derive a sum rule which involves only the $\tau_{1/2}^{(n)}$ and $\tau_{3/2}^{(n)}$ form factors and the corresponding level splittings. The latter strongly supports a theoretical evidence that the $B$ semileptonic decay into narrow orbitally-excited resonances dominates over the decay into the broad ones, in apparent contradiction with some recent experiments. We discuss this issue.
[ { "created": "Thu, 9 Mar 2000 18:18:06 GMT", "version": "v1" } ]
2016-09-06
[ [ "Yaouanc", "A. Le", "" ], [ "Melikhov", "D.", "" ], [ "Morénas", "V.", "" ], [ "Oliver", "L.", "" ], [ "Pène", "O.", "" ], [ "Raynal", "J. -C.", "" ] ]
We explicitly check quark-hadron duality to order $(m_b-m_c)\Lambda/m_b^2$ for $b \to c l\nu$ decays in the limit $m_b-m_c \ll m_b$ including ground state and orbitally excited hadrons. Duality occurs thanks to a new sum rule which expresses the subleading HQET form factor $\xi_3$ or, in other notations, $a_+^{(1)}$ in terms of the infinite mass limit form factors and some level splittings. We also demonstrate the sum rule, which is not restricted to the condition $m_b-m_c \ll m_b$, applying OPE to the longitudinal axial component of the hadronic tensor without neglecting the $1/m_b$ subleading contributions to the form factors. We argue that this method should produce a new class of sum rules, depending on the current, beyond Bjorken, Voloshin and the known tower of higher moments. Applying OPE to the vector currents we find another derivation of the Voloshin sum rule. From independent results on $\xi_3$ we derive a sum rule which involves only the $\tau_{1/2}^{(n)}$ and $\tau_{3/2}^{(n)}$ form factors and the corresponding level splittings. The latter strongly supports a theoretical evidence that the $B$ semileptonic decay into narrow orbitally-excited resonances dominates over the decay into the broad ones, in apparent contradiction with some recent experiments. We discuss this issue.
2402.11564
Muhammad Ridwan
Muhammad Ridwan, Ahmad Jafar Arifi, and Terry Mart
The Properties of Radially Excited Charmonia in The Light Front Quark Model
ITM Web Conf. Volume 61, 2024, The 9th International Symposium on Current Progress in Mathematics and Sciences 2023 (The 9th ISCPMS 2023) in conjunction with AUA Academic Conference on the Application of Artificial Intelligences and Data Sciences in a Modern Science for a Better Life, 9 pages
ITM Web Conf. Volume 61, 2024 (9 pages)
10.1051/itmconf/20246101016
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Investigating the properties of excited charmonia is important to clarify its internal structure. In this paper, we present the mass spectra (MS) and decay constants (DC) for charmonia up to 3S states calculated by means of the light-front quark model based on a variational approach. In particular, we consider the QCD-motivated effective Hamiltonian, which includes both confinement (linear and screened) and Coulomb-like potentials. Furthermore, since the existence of the nature of heavy quark symmetry, we treat hyperfine interactions perturbatively. We developed the harmonic oscillator expansion method to approximate the wave function (WF) for excited states. We found that the results of our theoretical calculations, using screened potentials rather than linear ones, are in good agreement with experimental data. By looking at the mass and decay constant result, we found that our result on the {\psi}(3S) state matched the properties of the {\psi}(4040) resonance.
[ { "created": "Sun, 18 Feb 2024 12:18:16 GMT", "version": "v1" } ]
2024-03-20
[ [ "Ridwan", "Muhammad", "" ], [ "Arifi", "Ahmad Jafar", "" ], [ "Mart", "Terry", "" ] ]
Investigating the properties of excited charmonia is important to clarify its internal structure. In this paper, we present the mass spectra (MS) and decay constants (DC) for charmonia up to 3S states calculated by means of the light-front quark model based on a variational approach. In particular, we consider the QCD-motivated effective Hamiltonian, which includes both confinement (linear and screened) and Coulomb-like potentials. Furthermore, since the existence of the nature of heavy quark symmetry, we treat hyperfine interactions perturbatively. We developed the harmonic oscillator expansion method to approximate the wave function (WF) for excited states. We found that the results of our theoretical calculations, using screened potentials rather than linear ones, are in good agreement with experimental data. By looking at the mass and decay constant result, we found that our result on the {\psi}(3S) state matched the properties of the {\psi}(4040) resonance.
hep-ph/9512261
Murman Margvelashvili
Ketino Aladashvili, Murman Margvelashvili (HEPI, Tbilisi)
On the Flavor Dependence of the Mixed Quark-Gluon Condensate
8 pages, latex, two figures in a separate uuencoded file. Submitted to Phys.Lett.B
Phys.Lett. B372 (1996) 299-305
10.1016/0370-2693(96)00043-3
TSU-HEPI 04-95
hep-ph
null
The flavour dependence of the mixed quark-gluon condensate is studied through the analysis of correlators of the hybrid current $a_{\mu}=g\bar s\gamma_{\rho}\gamma_5 G_{\rho\mu}d$. The flavour symmetry breaking for this type of condensates is found to be less than that for the quark condensates. For the ratio of strange to nonstrange condensates we obtain \mbox{$R=0.95\pm 0.15$}. For the kaon coupling to the current $a_\mu$ we find $\delta'^2=(0.020\pm0.005)GeV^2$, which is an order of magnitude smaller than analogous chirally unsuppressed coupling.
[ { "created": "Fri, 8 Dec 1995 21:37:52 GMT", "version": "v1" } ]
2009-10-28
[ [ "Aladashvili", "Ketino", "", "HEPI, Tbilisi" ], [ "Margvelashvili", "Murman", "", "HEPI, Tbilisi" ] ]
The flavour dependence of the mixed quark-gluon condensate is studied through the analysis of correlators of the hybrid current $a_{\mu}=g\bar s\gamma_{\rho}\gamma_5 G_{\rho\mu}d$. The flavour symmetry breaking for this type of condensates is found to be less than that for the quark condensates. For the ratio of strange to nonstrange condensates we obtain \mbox{$R=0.95\pm 0.15$}. For the kaon coupling to the current $a_\mu$ we find $\delta'^2=(0.020\pm0.005)GeV^2$, which is an order of magnitude smaller than analogous chirally unsuppressed coupling.
hep-ph/0407244
Sven Heinemeyer
S. Heinemeyer
MSSM Higgs Physics at Higher Orders
119 pages, lots of figures. Version with full resolution figures can be fount at http://quark.phy.bnl.gov/~heinemey/uni/paper/publ04.html
Int.J.Mod.Phys.A21:2659-2772,2006
10.1142/S0217751X06031028
CERN-PH-TH/2004-139, LMU 09/04
hep-ph
null
Various aspects of the Higgs boson phenomenology of the Minimal Supersymmetric Standard Model (MSSM) are reviewed. Emphasis is put on the effects of higher-order corrections. The masses and couplings are discussed in the MSSM with real and complex parameters. Higher-order corrections to Higgs boson production channels at a prospective e+ e- linear collider are investigated. Corrections to Higgs boson decays to SM fermions and their phenomenological implications for hadron and lepton colliders are explored.
[ { "created": "Wed, 21 Jul 2004 13:22:14 GMT", "version": "v1" } ]
2009-11-10
[ [ "Heinemeyer", "S.", "" ] ]
Various aspects of the Higgs boson phenomenology of the Minimal Supersymmetric Standard Model (MSSM) are reviewed. Emphasis is put on the effects of higher-order corrections. The masses and couplings are discussed in the MSSM with real and complex parameters. Higher-order corrections to Higgs boson production channels at a prospective e+ e- linear collider are investigated. Corrections to Higgs boson decays to SM fermions and their phenomenological implications for hadron and lepton colliders are explored.
hep-ph/0209158
Yasunori Nomura
Walter D. Goldberger, Yasunori Nomura, David R. Smith
Warped Supersymmetric Grand Unification
41 pages, LaTeX, version to appear in Phys. Rev. D
Phys.Rev.D67:075021,2003
10.1103/PhysRevD.67.075021
UCB-PTH-02/38, LBNL-51481, MIT-CTP-3305
hep-ph hep-th
null
We construct a realistic theory of grand unification in AdS_5 truncated by branes, in which the unified gauge symmetry is broken by boundary conditions and the electroweak scale is generated by the AdS warp factor. We show that the theory preserves the successful gauge coupling unification of the 4D MSSM at leading-logarithmic level. Kaluza-Klein (KK) towers, including those of XY gauge and colored Higgs multiplets, appear at the TeV scale, while the extra dimension provides natural mechanisms for doublet-triplet splitting and proton decay suppression. In one possible scenario supersymmetry is strongly broken on the TeV brane, in which case the lightest SU(3)_C x SU(2)_L x U(1)_Y gauginos are approximately Dirac and the mass of the lightest XY gaugino is pushed well below that of the lowest gauge boson KK mode, improving the prospects for its production at the LHC. The bulk Lagrangian possesses a symmetry that we call GUT parity. If GUT parity is exact, the lightest GUT particle, most likely an XY gaugino, is stable. Once produced in a collider, the XY gaugino hadronizes to form mesons, some of which will be charged and visible as highly ionizing tracks. The lightest supersymmetric particle is the gravitino of mass \sim 10^{-3} eV, which is also stable if R parity is conserved.
[ { "created": "Mon, 16 Sep 2002 19:40:33 GMT", "version": "v1" }, { "created": "Mon, 23 Sep 2002 23:49:38 GMT", "version": "v2" }, { "created": "Sat, 1 Mar 2003 00:16:40 GMT", "version": "v3" } ]
2008-11-26
[ [ "Goldberger", "Walter D.", "" ], [ "Nomura", "Yasunori", "" ], [ "Smith", "David R.", "" ] ]
We construct a realistic theory of grand unification in AdS_5 truncated by branes, in which the unified gauge symmetry is broken by boundary conditions and the electroweak scale is generated by the AdS warp factor. We show that the theory preserves the successful gauge coupling unification of the 4D MSSM at leading-logarithmic level. Kaluza-Klein (KK) towers, including those of XY gauge and colored Higgs multiplets, appear at the TeV scale, while the extra dimension provides natural mechanisms for doublet-triplet splitting and proton decay suppression. In one possible scenario supersymmetry is strongly broken on the TeV brane, in which case the lightest SU(3)_C x SU(2)_L x U(1)_Y gauginos are approximately Dirac and the mass of the lightest XY gaugino is pushed well below that of the lowest gauge boson KK mode, improving the prospects for its production at the LHC. The bulk Lagrangian possesses a symmetry that we call GUT parity. If GUT parity is exact, the lightest GUT particle, most likely an XY gaugino, is stable. Once produced in a collider, the XY gaugino hadronizes to form mesons, some of which will be charged and visible as highly ionizing tracks. The lightest supersymmetric particle is the gravitino of mass \sim 10^{-3} eV, which is also stable if R parity is conserved.
hep-ph/9609301
John Gracey
J.A. Gracey
Anomalous dimensions of operators in polarized deep inelastic scattering at O(1/N_f)
22 latex pages plus 7 figures
Nucl.Phys.B480:73-98,1996
10.1016/S0550-3213(96)00485-3
LTH 384
hep-ph
null
Critical exponents are computed for a variety of twist-2 composite operators, which occur in polarized and unpolarized deep inelastic scattering, at leading order in the 1/N_f expansion. The resulting d-dimensional expressions, which depend on the moment of the operator, are in agreement with recent explicit two and three loop perturbative calculations. An interesting aspect of the critical point approach which is used, is that the anomalous dimensions of the flavour singlet eigenoperators, which diagonalize the perturbative mixing matrix, are computed directly. We also elucidate the treatment of gamma^5 at the fixed point which is important in simplifying the calculation for polarized operators. Finally, the anomalous dimension of the singlet axial current is determined at O(1/N_f) by considering the renormalization of the anomaly in operator form.
[ { "created": "Tue, 10 Sep 1996 08:53:05 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gracey", "J. A.", "" ] ]
Critical exponents are computed for a variety of twist-2 composite operators, which occur in polarized and unpolarized deep inelastic scattering, at leading order in the 1/N_f expansion. The resulting d-dimensional expressions, which depend on the moment of the operator, are in agreement with recent explicit two and three loop perturbative calculations. An interesting aspect of the critical point approach which is used, is that the anomalous dimensions of the flavour singlet eigenoperators, which diagonalize the perturbative mixing matrix, are computed directly. We also elucidate the treatment of gamma^5 at the fixed point which is important in simplifying the calculation for polarized operators. Finally, the anomalous dimension of the singlet axial current is determined at O(1/N_f) by considering the renormalization of the anomaly in operator form.
2406.00946
Huaicong Hu
Huai-cong Hu, Zhao-Yang Zhang, Ning-Yu Zhu, Hai-Xiang Chen
Higgs boson decays $h\rightarrow MZ$ in the TNMSSM
Accepted for published in Chinese Physics C
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the SM-like Higgs boson decays $h\rightarrow MZ$ in the Triplet extended NMSSM (TNMSSM),where M is a vector meson ($\rho$, $\omega$, $\phi$, $J/\Psi$, $\Upsilon$). Compared to the minimal supersymmetric standard model (MSSM), the TNMSSM includes two new SU(2) triplets with hypercharge $\pm 1$ and a SM gauge singlet which are coupled to each other. The indirect contributions to the decays $h \rightarrow MZ$ are produced from the effective $h\gamma Z$ vertex, and they are more important than the direct contributions. The results of this work would encourage a detection on $h \rightarrow Z\gamma$ at the future high energy colliders for exploring new physics beyond the SM.
[ { "created": "Mon, 3 Jun 2024 02:57:20 GMT", "version": "v1" } ]
2024-06-04
[ [ "Hu", "Huai-cong", "" ], [ "Zhang", "Zhao-Yang", "" ], [ "Zhu", "Ning-Yu", "" ], [ "Chen", "Hai-Xiang", "" ] ]
We study the SM-like Higgs boson decays $h\rightarrow MZ$ in the Triplet extended NMSSM (TNMSSM),where M is a vector meson ($\rho$, $\omega$, $\phi$, $J/\Psi$, $\Upsilon$). Compared to the minimal supersymmetric standard model (MSSM), the TNMSSM includes two new SU(2) triplets with hypercharge $\pm 1$ and a SM gauge singlet which are coupled to each other. The indirect contributions to the decays $h \rightarrow MZ$ are produced from the effective $h\gamma Z$ vertex, and they are more important than the direct contributions. The results of this work would encourage a detection on $h \rightarrow Z\gamma$ at the future high energy colliders for exploring new physics beyond the SM.
1606.05118
Gang Li
Qi Wu, Gang Li, Fenglan Shao, Qianwen Wang, Ruiqin Wang, Yawei Zhang and Ying Zheng
Production of the $X_b$ in $\Upsilon(5S, 6S)\to \gamma X_b$ radiative decays
11 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we investigate the production of $X_b$ in the process $\Upsilon(5S,6S)\to \gamma X_b$, where $X_b$ is assumed to be the counterpart of $X(3872)$ in the bottomonium sector as a $B {\bar B}^*$ molecular state. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate their production ratios. Our results have shown that the production ratios for the $\Upsilon(5S,6S) \to \gamma X_b$ are orders of $10^{-5}$ with reasonable cutoff parameter range $\alpha \simeq 2\sim 3$. The sizeable production ratios may be accessible at the future experiments like forthcoming BelleII, which will provide important clues to the inner structures of the exotic state $X_b$.
[ { "created": "Thu, 16 Jun 2016 10:03:49 GMT", "version": "v1" } ]
2016-06-17
[ [ "Wu", "Qi", "" ], [ "Li", "Gang", "" ], [ "Shao", "Fenglan", "" ], [ "Wang", "Qianwen", "" ], [ "Wang", "Ruiqin", "" ], [ "Zhang", "Yawei", "" ], [ "Zheng", "Ying", "" ] ]
In this work, we investigate the production of $X_b$ in the process $\Upsilon(5S,6S)\to \gamma X_b$, where $X_b$ is assumed to be the counterpart of $X(3872)$ in the bottomonium sector as a $B {\bar B}^*$ molecular state. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate their production ratios. Our results have shown that the production ratios for the $\Upsilon(5S,6S) \to \gamma X_b$ are orders of $10^{-5}$ with reasonable cutoff parameter range $\alpha \simeq 2\sim 3$. The sizeable production ratios may be accessible at the future experiments like forthcoming BelleII, which will provide important clues to the inner structures of the exotic state $X_b$.
1105.3149
Thomas Teubner
K. Hagiwara, R. Liao, A.D. Martin, Daisuke Nomura and T. Teubner
(g-2)_mu and alpha(M_Z^2) re-evaluated using new precise data
30 pages, including 18 figures. Minor changes, published version
J. Phys. G 38 (2011) 085003
10.1088/0954-3899/38/8/085003
KEK-TH-1458, LTH 913, IPPP/11/18, DCPT/11/36, TU-883
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We update our Standard Model predictions for g-2 of the muon and for the hadronic contributions to the running of the QED coupling, Delta alpha_had^(5)(M_Z^2). Particular emphasis is put on recent changes in the hadronic contributions from new data in the 2pi channel and from the energy region just below 2 GeV. In particular, for the e+e- -> pi+pi- contribution we include the recent `radiative return' data from KLOE and BaBar. We also include the recent BaBar data on other exclusive channels. We make a detailed study of the effect of replacing the measurements of the inclusive cross section, sigma(e+e- -> hadrons), by the sum of the exclusive channels in the energy interval 1.43 < sqrt{s} < 2 GeV, which includes a QCD sum-rule analysis of this energy region. Our favoured prediction for the muon anomalous magnetic moment is (g-2)/2 = (11659182.8 +- 4.9)*10^(-10) which is 3.3 sigma below the present world-average measurement. We compare our g-2 value with other recent calculations. Our prediction for the QED coupling, obtained via Delta alpha_had^(5)(M_Z^2) = (276.26 +- 1.38)*10^(-4), is alpha(M_Z^2)^(-1) = 128.944 +- 0.019.
[ { "created": "Mon, 16 May 2011 17:03:58 GMT", "version": "v1" }, { "created": "Fri, 5 Aug 2011 16:48:55 GMT", "version": "v2" } ]
2015-05-28
[ [ "Hagiwara", "K.", "" ], [ "Liao", "R.", "" ], [ "Martin", "A. D.", "" ], [ "Nomura", "Daisuke", "" ], [ "Teubner", "T.", "" ] ]
We update our Standard Model predictions for g-2 of the muon and for the hadronic contributions to the running of the QED coupling, Delta alpha_had^(5)(M_Z^2). Particular emphasis is put on recent changes in the hadronic contributions from new data in the 2pi channel and from the energy region just below 2 GeV. In particular, for the e+e- -> pi+pi- contribution we include the recent `radiative return' data from KLOE and BaBar. We also include the recent BaBar data on other exclusive channels. We make a detailed study of the effect of replacing the measurements of the inclusive cross section, sigma(e+e- -> hadrons), by the sum of the exclusive channels in the energy interval 1.43 < sqrt{s} < 2 GeV, which includes a QCD sum-rule analysis of this energy region. Our favoured prediction for the muon anomalous magnetic moment is (g-2)/2 = (11659182.8 +- 4.9)*10^(-10) which is 3.3 sigma below the present world-average measurement. We compare our g-2 value with other recent calculations. Our prediction for the QED coupling, obtained via Delta alpha_had^(5)(M_Z^2) = (276.26 +- 1.38)*10^(-4), is alpha(M_Z^2)^(-1) = 128.944 +- 0.019.
hep-ph/9605318
Dennis Silverman
Dennis Silverman (U.C. Irvine)
Anomalous Chromomagnetic Moments of Quarks and Large Transverse Energy Jets
REVTeX, 11 pages, 2 postscript figures
Phys.Rev.D54:5563-5566,1996
10.1103/PhysRevD.54.5563
SLAC-PUB-7166, U.C. Irvine TR-96-12
hep-ph
null
We consider the jet cross sections for gluons coupling to quarks with an anomalous chromomagnetic moment. We then apply this to the deviation and bounds from QCD found in the CDF and D0 Fermilab data, respectively, to find a range of possible values for the anomalous moments. The quadratic and quartic terms in the anomalous moments can fit to the rise of a deviation with transverse energy. Since previous analyses have been done on the top quark total cross section, here we assume the same moment on all quarks except the top and find the range $|\kappa'| \equiv |\kappa/(2 m_q)| = 1.0\pm 0.3$ TeV$^{-1}$ for the CDF data. Assuming the anomalous moment is present only on a charm or bottom quark which is pair produced results in a range $|\kappa'_{b,c}| = 3.5 \pm 1.0 $ TeV$^{-1}$. The magnitudes here are compared with anomalous magnetic moments that could account for $R_b$ and found to be in the same general range, as well as not inconsistent with LEP and SLD bounds on $\Delta \Gamma_{\text{had}}$.
[ { "created": "Wed, 15 May 1996 13:55:35 GMT", "version": "v1" } ]
2011-01-25
[ [ "Silverman", "Dennis", "", "U.C. Irvine" ] ]
We consider the jet cross sections for gluons coupling to quarks with an anomalous chromomagnetic moment. We then apply this to the deviation and bounds from QCD found in the CDF and D0 Fermilab data, respectively, to find a range of possible values for the anomalous moments. The quadratic and quartic terms in the anomalous moments can fit to the rise of a deviation with transverse energy. Since previous analyses have been done on the top quark total cross section, here we assume the same moment on all quarks except the top and find the range $|\kappa'| \equiv |\kappa/(2 m_q)| = 1.0\pm 0.3$ TeV$^{-1}$ for the CDF data. Assuming the anomalous moment is present only on a charm or bottom quark which is pair produced results in a range $|\kappa'_{b,c}| = 3.5 \pm 1.0 $ TeV$^{-1}$. The magnitudes here are compared with anomalous magnetic moments that could account for $R_b$ and found to be in the same general range, as well as not inconsistent with LEP and SLD bounds on $\Delta \Gamma_{\text{had}}$.
hep-ph/0512165
Pedro David Ruiz-Femenia
Andre Hoang and Pedro Ruiz-Femenia
Nonrelativistic QCD for coloured scalar fields
4 pages, 3 figures, uses PoS style. Contribution to the proceedings of the International Europhysics Conference on High Energy Physics (HEP2005), Lisboa, Portugal, 21-27 July 2005
null
null
MPP-2005-162
hep-ph
null
We present an effective field theory suitable to describe a non-relativistic particle-antiparticle pair of heavy scalars based on the gauge group SU(3). Its formulation is analogous to that of "velocity NRQCD" (vNRQCD), a non-relativistic effective theory for heavy quark pairs. The matching conditions with scalar QCD and the renormalization group evolution of the effective theory are discussed. The non-relativistic framework proposed here suffices to compute scalar-antiscalar bound state energies at next-to-next-to-leading-logarithmic (NNLL) order and next-to-leading-logarithmic (NLL) threshold production of squarks in $e^+e^-$ and $\gamma\gamma$ collisions, in particular of the lighter scalar top quark at a future Linear Collider.
[ { "created": "Tue, 13 Dec 2005 17:50:47 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hoang", "Andre", "" ], [ "Ruiz-Femenia", "Pedro", "" ] ]
We present an effective field theory suitable to describe a non-relativistic particle-antiparticle pair of heavy scalars based on the gauge group SU(3). Its formulation is analogous to that of "velocity NRQCD" (vNRQCD), a non-relativistic effective theory for heavy quark pairs. The matching conditions with scalar QCD and the renormalization group evolution of the effective theory are discussed. The non-relativistic framework proposed here suffices to compute scalar-antiscalar bound state energies at next-to-next-to-leading-logarithmic (NNLL) order and next-to-leading-logarithmic (NLL) threshold production of squarks in $e^+e^-$ and $\gamma\gamma$ collisions, in particular of the lighter scalar top quark at a future Linear Collider.
hep-ph/9805298
Robert Thorne
R.S. Thorne
Heavy Quarks and Structure Functions
4pages, Latex, 2 postscript figures. Contribution to International Workshop on Deep Inelastic Scattering and QCD, DIS98, Brussels, Belgium, April 1998
null
null
null
hep-ph
null
I present a method for calculating heavy quark production which extrapolates smoothly from the well understood limits of the fixed-flavour number scheme for Q^2 approx m_H^2 to the zero-mass scheme at Q^2/m_H^2 -> infinity. For all Q^2 > m_H^2 the evolution of the heavy quark distribution is precisely as in the massless MSbar scheme. The method is simple to implement and compares well with data.
[ { "created": "Tue, 12 May 1998 15:56:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Thorne", "R. S.", "" ] ]
I present a method for calculating heavy quark production which extrapolates smoothly from the well understood limits of the fixed-flavour number scheme for Q^2 approx m_H^2 to the zero-mass scheme at Q^2/m_H^2 -> infinity. For all Q^2 > m_H^2 the evolution of the heavy quark distribution is precisely as in the massless MSbar scheme. The method is simple to implement and compares well with data.
1503.08531
Michael Trusov
Yu.A. Simonov, M.A. Trusov
Confinement and $\alpha_s$ in a strong magnetic field
14 pages; 2 figures; LaTeX2e
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hadron decay widths are shown to increase in strong magnetic fields as $\Gamma (eB) \sim \frac{eB}{\kappa} \Gamma(0)$. The same mechanism is shown to be present in the production of the sea quark pair inside the confining string, which decreases the string tension with the growing $eB$ parallel to the string . On the other hand, the average energy of the $q\bar q$ holes in the string world sheet increases, when the direction of $\mathbf{B}$ is perpendicular to the sheet. These two effects stipulate the spectacular picture of the $\mathbf{B}$ dependent confinement and $\alpha_s$, discovered on the lattice.
[ { "created": "Mon, 30 Mar 2015 04:49:06 GMT", "version": "v1" }, { "created": "Wed, 1 Apr 2015 18:25:10 GMT", "version": "v2" } ]
2015-04-02
[ [ "Simonov", "Yu. A.", "" ], [ "Trusov", "M. A.", "" ] ]
Hadron decay widths are shown to increase in strong magnetic fields as $\Gamma (eB) \sim \frac{eB}{\kappa} \Gamma(0)$. The same mechanism is shown to be present in the production of the sea quark pair inside the confining string, which decreases the string tension with the growing $eB$ parallel to the string . On the other hand, the average energy of the $q\bar q$ holes in the string world sheet increases, when the direction of $\mathbf{B}$ is perpendicular to the sheet. These two effects stipulate the spectacular picture of the $\mathbf{B}$ dependent confinement and $\alpha_s$, discovered on the lattice.
2002.10275
We-Fu Chang
We-Fu Chang and Jiajun Liao
Constraints on light singlet fermion interactions from coherent elastic neutrino-nucleus scattering
23 pages, 4 figures, References added. To match the published version
Phys. Rev. D 102, 075004 (2020)
10.1103/PhysRevD.102.075004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exotic singlet fermions $\chi$, with a mass $m_\chi\lesssim 50$ MeV, could be produced at the coherent elastic neutrino-nucleus scattering (CE$\nu$NS) experiments through the $\nu {\mathcal N} \rightarrow \chi {\mathcal N}$ process. Due to the coherent enhancement, it offers a unique way to study how $\chi$ interacts with the Standard Model (SM) sector. Based on the most general dimension-6 effective Lagrangian, we perform a comprehensive study on the relevant interaction between $\chi$ and the SM sector. From the current and future COHERENT and future CONUS experiments, we obtain the upper bounds on the Wilson coefficients for the dipole, scalar, vector, and tensor interactions. For $m_\chi $ below 10 MeV, future CONUS data has the best sensitivity, while for $m_\chi$ between 10 MeV$-50$ MeV, the current and future COHERENT bounds dominate. These limits are complementary to those from neutrino oscillation and collider searches. Moreover, the bounds do not depend on the charge conjugation property of $\chi$, nor whether $\chi$ is dark matter or not.
[ { "created": "Mon, 24 Feb 2020 14:09:02 GMT", "version": "v1" }, { "created": "Thu, 5 Mar 2020 01:46:31 GMT", "version": "v2" }, { "created": "Thu, 8 Oct 2020 15:27:00 GMT", "version": "v3" } ]
2020-10-14
[ [ "Chang", "We-Fu", "" ], [ "Liao", "Jiajun", "" ] ]
The exotic singlet fermions $\chi$, with a mass $m_\chi\lesssim 50$ MeV, could be produced at the coherent elastic neutrino-nucleus scattering (CE$\nu$NS) experiments through the $\nu {\mathcal N} \rightarrow \chi {\mathcal N}$ process. Due to the coherent enhancement, it offers a unique way to study how $\chi$ interacts with the Standard Model (SM) sector. Based on the most general dimension-6 effective Lagrangian, we perform a comprehensive study on the relevant interaction between $\chi$ and the SM sector. From the current and future COHERENT and future CONUS experiments, we obtain the upper bounds on the Wilson coefficients for the dipole, scalar, vector, and tensor interactions. For $m_\chi $ below 10 MeV, future CONUS data has the best sensitivity, while for $m_\chi$ between 10 MeV$-50$ MeV, the current and future COHERENT bounds dominate. These limits are complementary to those from neutrino oscillation and collider searches. Moreover, the bounds do not depend on the charge conjugation property of $\chi$, nor whether $\chi$ is dark matter or not.
2402.00621
Tyler Gorda
Jes\'us Cruz Rojas, Tyler Gorda, Carlos Hoyos, Niko Jokela, Matti J\"arvinen, Aleksi Kurkela, Risto Paatelainen, Saga S\"appi, Aleksi Vuorinen
Estimate for the bulk viscosity of strongly coupled quark matter
18 pages, 6 figures
null
null
APCTP Pre2024 - 003, HIP-2024-1/TH, TUM-EFT 187/24
hep-ph astro-ph.HE hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern hydrodynamic simulations of core-collapse supernovae and neutron-star mergers require knowledge not only of the equilibrium properties of strongly interacting matter, but also of the system's response to perturbations, encoded in various transport coefficients. Using perturbative and holographic tools, we derive here an improved weak-coupling and a new strong-coupling result for the most important transport coefficient of unpaired quark matter, its bulk viscosity. These results are combined in a simple analytic pocket formula for the quantity that is rooted in perturbative Quantum Chromodynamics at high densities but takes into account nonperturbative holographic input at neutron-star densities, where the system is strongly coupled. This expression can be used in the modeling of unpaired quark matter at astrophysically relevant temperatures and densities.
[ { "created": "Thu, 1 Feb 2024 14:31:23 GMT", "version": "v1" } ]
2024-02-02
[ [ "Rojas", "Jesús Cruz", "" ], [ "Gorda", "Tyler", "" ], [ "Hoyos", "Carlos", "" ], [ "Jokela", "Niko", "" ], [ "Järvinen", "Matti", "" ], [ "Kurkela", "Aleksi", "" ], [ "Paatelainen", "Risto", "" ], [ ...
Modern hydrodynamic simulations of core-collapse supernovae and neutron-star mergers require knowledge not only of the equilibrium properties of strongly interacting matter, but also of the system's response to perturbations, encoded in various transport coefficients. Using perturbative and holographic tools, we derive here an improved weak-coupling and a new strong-coupling result for the most important transport coefficient of unpaired quark matter, its bulk viscosity. These results are combined in a simple analytic pocket formula for the quantity that is rooted in perturbative Quantum Chromodynamics at high densities but takes into account nonperturbative holographic input at neutron-star densities, where the system is strongly coupled. This expression can be used in the modeling of unpaired quark matter at astrophysically relevant temperatures and densities.
1302.5098
Michael Strickland
Maximilian Attems, Anton Rebhan, and Michael Strickland
The chromo-Weibel instability in an expanding background
8 pages, 3 figures; Proceedings contribution for the International Symposium on Multiparticle Dynamics, Kielce, Poland, Sept 2012
Acta Phys. Polon. Supp. 6, 393-402 (2013)
10.5506/APhysPolBSupp.6.393
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this proceedings contribution we review recent calculations of the dynamics of the chromo-Weibel instability in the quark gluon plasma. This instability is present in gauge theories with a one-particle distribution function which is momentum-space anisotropic in the local rest frame. The conditions necessary for triggering this instability can be present already in the color-glass-condensate initial state or dynamically generated by the rapid longitudinal expansion of the matter created in a heavy-ion collision. Using the hard-loop framework we study the case that the one-particle distribution function possesses an arbitrary initial momentum anisotropy that increases in time due to longitudinal free streaming. The resulting three-dimensional dynamical equations for the chromofield evolution are solved numerically. We find that there is regeneration of the longitudinal pressure due to unstable plasma modes; nevertheless, the system seems to maintain a high-degree of momentum-space anisotropy. Despite this anisotropy, we find that there is rapid longitudinal thermalization of the plasma due to the non-linear mode couplings inherent in the unstable evolution.
[ { "created": "Wed, 20 Feb 2013 20:51:14 GMT", "version": "v1" } ]
2013-07-22
[ [ "Attems", "Maximilian", "" ], [ "Rebhan", "Anton", "" ], [ "Strickland", "Michael", "" ] ]
In this proceedings contribution we review recent calculations of the dynamics of the chromo-Weibel instability in the quark gluon plasma. This instability is present in gauge theories with a one-particle distribution function which is momentum-space anisotropic in the local rest frame. The conditions necessary for triggering this instability can be present already in the color-glass-condensate initial state or dynamically generated by the rapid longitudinal expansion of the matter created in a heavy-ion collision. Using the hard-loop framework we study the case that the one-particle distribution function possesses an arbitrary initial momentum anisotropy that increases in time due to longitudinal free streaming. The resulting three-dimensional dynamical equations for the chromofield evolution are solved numerically. We find that there is regeneration of the longitudinal pressure due to unstable plasma modes; nevertheless, the system seems to maintain a high-degree of momentum-space anisotropy. Despite this anisotropy, we find that there is rapid longitudinal thermalization of the plasma due to the non-linear mode couplings inherent in the unstable evolution.
hep-ph/0403219
Steven D. Bass
Steven D. Bass
Anomalous commutators and electroweak baryogenesis
9 pages
Phys.Lett. B590 (2004) 115-119
10.1016/j.physletb.2004.03.085
null
hep-ph
null
Electroweak vacuum transition processes (sphalerons) in the early Universe provide a possible explanation of the baryon asymmetry. Combining this physics with the anomalous commutators of Adler and Boulware and renormalization group invariance, we argue that electroweak baryon number violation also induces a ``topological condensate'' in the vacuum. QCD sphaleron processes act to distribute the baryon number violation between both left and right handed quarks and induce a spin independent component in this ``condensate''.
[ { "created": "Fri, 19 Mar 2004 17:17:45 GMT", "version": "v1" } ]
2009-11-10
[ [ "Bass", "Steven D.", "" ] ]
Electroweak vacuum transition processes (sphalerons) in the early Universe provide a possible explanation of the baryon asymmetry. Combining this physics with the anomalous commutators of Adler and Boulware and renormalization group invariance, we argue that electroweak baryon number violation also induces a ``topological condensate'' in the vacuum. QCD sphaleron processes act to distribute the baryon number violation between both left and right handed quarks and induce a spin independent component in this ``condensate''.
1407.0264
Tao Liu
Alexander Kurz, Tao Liu, Peter Marquard, Matthias Steinhauser
Higher-order hadronic and heavy-lepton contributions to the anomalous magnetic moment
Contribution to the proceedings of Loops and Legs in Quantum Field Theory, 27 April - 2 May 2014, Weimar, Germany
null
null
DESY 14-112, LPN14-079, SFB/CPP-14-34, TTP14-017
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result, $a_\mu^{\rm{had,NNLO}}=1.24\pm 0.01 \times 10^{-10}$, is of the same order of magnitude as the current uncertainty from the hadronic contributions. For heavy-lepton corrections, analytical results are obtained at four-loop order and compared with the known results.
[ { "created": "Tue, 1 Jul 2014 14:50:03 GMT", "version": "v1" } ]
2014-07-02
[ [ "Kurz", "Alexander", "" ], [ "Liu", "Tao", "" ], [ "Marquard", "Peter", "" ], [ "Steinhauser", "Matthias", "" ] ]
We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result, $a_\mu^{\rm{had,NNLO}}=1.24\pm 0.01 \times 10^{-10}$, is of the same order of magnitude as the current uncertainty from the hadronic contributions. For heavy-lepton corrections, analytical results are obtained at four-loop order and compared with the known results.
hep-ph/0011227
Sang Pyo Kim
Sang Pyo Kim (Univ. of Alberta, Kunsan Nat'l Univ.) Chul H. Lee (Hanyang Univ.)
Emergence of Classicality in Quantum Phase Transitions
RevTex 13 pages, no figures. Decoherence discussed in a linear coupling model. Version to appear in Phys. Rev. D
Phys.Rev. D65 (2002) 045013
10.1103/PhysRevD.65.045013
null
hep-ph cond-mat.stat-mech hep-th nucl-th
null
We show that classicality emerges during quantum phase transitions due to parametric interactions without coupling to environments. The Wigner functions are explicitly calculated for the Gaussian vacuum, number, and thermal states of a free scalar field that describes the spinodal instability regime. The Wigner functions are sharply peaked around their classical trajectories during the phase transition and exhibit classical correlation only for unstable long wavelength modes but retain quantum coherence for short wavelength modes. Thus classicality emerges from the quantum evolution of phase transitions without a classical order parameter. We define a quantal ordering parameter that is linear in the field variable and satisfies the classical field equation.
[ { "created": "Fri, 17 Nov 2000 23:00:29 GMT", "version": "v1" }, { "created": "Mon, 12 Nov 2001 19:44:11 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kim", "Sang Pyo", "", "Univ. of Alberta, Kunsan Nat'l Univ." ], [ "Lee", "Chul H.", "", "Hanyang Univ." ] ]
We show that classicality emerges during quantum phase transitions due to parametric interactions without coupling to environments. The Wigner functions are explicitly calculated for the Gaussian vacuum, number, and thermal states of a free scalar field that describes the spinodal instability regime. The Wigner functions are sharply peaked around their classical trajectories during the phase transition and exhibit classical correlation only for unstable long wavelength modes but retain quantum coherence for short wavelength modes. Thus classicality emerges from the quantum evolution of phase transitions without a classical order parameter. We define a quantal ordering parameter that is linear in the field variable and satisfies the classical field equation.
hep-ph/0006244
E. Martynov
P.Desgrolard, M.Giffon, E.Martynov, E.Predazzi
Exchange-degenerate Regge trajectories: a fresh look from resonance and forward scattering regions
13 pages, LaTeX2e, 4 eps figures. Revised version accepted for publication in European Physical Journal C
Eur.Phys.J.C18:555-561,2001
10.1007/s100520100548
LYCEN 2000-60, DFTT 28/2000
hep-ph
null
The exchange-degeneracy of the mesonic $f$, $\omega $, $\rho $ and $a_{2}$ Regge trajectories, dominant at moderate and high energies in hadron elastic scattering, is analyzed from two viewpoints. The first one concerns the masses of the resonances lying on these trajectories; the second one deals with the total cross-sections and the ratios of the real to the imaginary parts of the forward amplitudes of hadron and photon induced reactions. Neither set of data supports exact exchange-degeneracy.
[ { "created": "Wed, 21 Jun 2000 08:44:13 GMT", "version": "v1" }, { "created": "Sun, 19 Nov 2000 00:06:58 GMT", "version": "v2" } ]
2009-01-07
[ [ "Desgrolard", "P.", "" ], [ "Giffon", "M.", "" ], [ "Martynov", "E.", "" ], [ "Predazzi", "E.", "" ] ]
The exchange-degeneracy of the mesonic $f$, $\omega $, $\rho $ and $a_{2}$ Regge trajectories, dominant at moderate and high energies in hadron elastic scattering, is analyzed from two viewpoints. The first one concerns the masses of the resonances lying on these trajectories; the second one deals with the total cross-sections and the ratios of the real to the imaginary parts of the forward amplitudes of hadron and photon induced reactions. Neither set of data supports exact exchange-degeneracy.
2204.11935
James Gratrex
James Gratrex, Bla\v{z}enka Meli\'c and Ivan Ni\v{s}and\v{z}i\'c
Lifetimes of singly charmed hadrons
68 pages, 6 figures. v2: two references added; cosmetic changes to all figures; some typos corrected; numerics and conclusions unchanged. Text updated to correspond with journal version
JHEP 07 (2022) 058
10.1007/JHEP07(2022)058
RBI-ThPhys-2022-8
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We provide an extensive study of the lifetimes of singly charmed baryons and mesons, within the heavy quark expansion with all known corrections included. A special attention is devoted to the choice of the charm mass and wavefunctions of heavy baryons. We give our predictions for lifetimes, lifetime ratios, and semileptonic branching ratios of singly charmed baryons. Our results accommodate the experimentally-favoured hierarchy of singly charmed baryon lifetimes \begin{eqnarray*} \tau\left(\Xi_c^{0}\right) < \tau\left(\Lambda_c^{+}\right)< \tau\left(\Omega_c^{0}\right) < \tau\left(\Xi_c^{+}\right)\, \end{eqnarray*} in contrast to earlier theoretical findings. Predictions for charmed meson lifetimes and semileptonic decay rates are in agreement with a recent comprehensive study and experimental results within uncertainties.
[ { "created": "Mon, 25 Apr 2022 19:29:43 GMT", "version": "v1" }, { "created": "Mon, 11 Jul 2022 16:44:03 GMT", "version": "v2" } ]
2022-07-12
[ [ "Gratrex", "James", "" ], [ "Melić", "Blaženka", "" ], [ "Nišandžić", "Ivan", "" ] ]
We provide an extensive study of the lifetimes of singly charmed baryons and mesons, within the heavy quark expansion with all known corrections included. A special attention is devoted to the choice of the charm mass and wavefunctions of heavy baryons. We give our predictions for lifetimes, lifetime ratios, and semileptonic branching ratios of singly charmed baryons. Our results accommodate the experimentally-favoured hierarchy of singly charmed baryon lifetimes \begin{eqnarray*} \tau\left(\Xi_c^{0}\right) < \tau\left(\Lambda_c^{+}\right)< \tau\left(\Omega_c^{0}\right) < \tau\left(\Xi_c^{+}\right)\, \end{eqnarray*} in contrast to earlier theoretical findings. Predictions for charmed meson lifetimes and semileptonic decay rates are in agreement with a recent comprehensive study and experimental results within uncertainties.
hep-ph/0111093
M. V. T. Machado
M.B. Gay Ducati, M.V.T. Machado
Unitarity Corrections to the Proton Structure Functions through the Dipole Picture
16 pages, 8 figures. Version to be published in Phys. Rev. D
Phys.Rev. D65 (2002) 114019
10.1103/PhysRevD.65.114019
null
hep-ph
null
We study the dipole picture for the description of the deep inelastic scattering, focusing on the structure functions which are driven directly by the gluon distribution. One performs estimates using the effective dipole cross section given by the Glauber-Mueller approach in QCD, which encodes the corrections due to the unitarity effects associated with the saturation phenomenon. We also address issues about frame invariance of the calculations when analysing the observables.
[ { "created": "Thu, 8 Nov 2001 17:22:00 GMT", "version": "v1" }, { "created": "Wed, 24 Apr 2002 18:07:25 GMT", "version": "v2" } ]
2015-06-25
[ [ "Ducati", "M. B. Gay", "" ], [ "Machado", "M. V. T.", "" ] ]
We study the dipole picture for the description of the deep inelastic scattering, focusing on the structure functions which are driven directly by the gluon distribution. One performs estimates using the effective dipole cross section given by the Glauber-Mueller approach in QCD, which encodes the corrections due to the unitarity effects associated with the saturation phenomenon. We also address issues about frame invariance of the calculations when analysing the observables.
hep-ph/9907563
Reinhard Alkofer
R. Alkofer, S. Ahlig, C. Fischer, M. Oettel, and H. Reinhardt
Octet and Decuplet Baryons in a Confining and Covariant Diquark-Quark Model
4 pages, 1 figure; talk given by R. Alkofer at PANIC 99
Nucl.Phys.A663:683-686,2000
10.1016/S0375-9474(99)00721-6
UNITU-THEP-7/1999
hep-ph
null
We treat baryons as bound states of scalar or axialvector diquarks and a constituent quark which interact through quark exchange. We obtain fully four-dimensional wave functions for both octet and decuplet baryons as solutions of the corresponding Bethe-Salpeter equation. Applications currently under investigation are: electromagnetic and strong form factors and strangeness production processes.
[ { "created": "Fri, 30 Jul 1999 12:50:51 GMT", "version": "v1" } ]
2008-11-26
[ [ "Alkofer", "R.", "" ], [ "Ahlig", "S.", "" ], [ "Fischer", "C.", "" ], [ "Oettel", "M.", "" ], [ "Reinhardt", "H.", "" ] ]
We treat baryons as bound states of scalar or axialvector diquarks and a constituent quark which interact through quark exchange. We obtain fully four-dimensional wave functions for both octet and decuplet baryons as solutions of the corresponding Bethe-Salpeter equation. Applications currently under investigation are: electromagnetic and strong form factors and strangeness production processes.
2312.02067
Simone Zoia
Francesco Calisto, Ryan Moodie, Simone Zoia
Learning Feynman integrals from differential equations with neural networks
33 pages, 12 figures, 3 tables, 2 appendices; published version
JHEP 07 (2024) 124
10.1007/JHEP07(2024)124
CERN-TH-2023-225
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We perform an exploratory study of a new approach for evaluating Feynman integrals numerically. We apply the recently-proposed framework of physics-informed deep learning to train neural networks to approximate the solution to the differential equations satisfied by the Feynman integrals. This approach relies neither on a canonical form of the differential equations, which is often a bottleneck for the analytical techniques, nor on the availability of a large dataset, and after training yields essentially instantaneous evaluation times. We provide a proof-of-concept implementation within the PyTorch framework, and apply it to a number of one- and two-loop examples, achieving a mean magnitude of relative difference of around 1% at two loops in the physical phase space with network training times on the order of an hour on a laptop GPU.
[ { "created": "Mon, 4 Dec 2023 17:26:49 GMT", "version": "v1" }, { "created": "Tue, 23 Jul 2024 08:39:14 GMT", "version": "v2" } ]
2024-07-24
[ [ "Calisto", "Francesco", "" ], [ "Moodie", "Ryan", "" ], [ "Zoia", "Simone", "" ] ]
We perform an exploratory study of a new approach for evaluating Feynman integrals numerically. We apply the recently-proposed framework of physics-informed deep learning to train neural networks to approximate the solution to the differential equations satisfied by the Feynman integrals. This approach relies neither on a canonical form of the differential equations, which is often a bottleneck for the analytical techniques, nor on the availability of a large dataset, and after training yields essentially instantaneous evaluation times. We provide a proof-of-concept implementation within the PyTorch framework, and apply it to a number of one- and two-loop examples, achieving a mean magnitude of relative difference of around 1% at two loops in the physical phase space with network training times on the order of an hour on a laptop GPU.
hep-ph/0612080
Xiao-Gang He
Xiao-Gang He (NTU)
$A_4$ Group and Tri-bimaximal Neutrino Mixing -- A Renormalizable Model
4 pages
Nucl.Phys.Proc.Suppl.168:350-352,2007
10.1016/j.nuclphysbps.2007.02.034
null
hep-ph
null
The tetrahedron $A_4$ group has been widely used in studying neutrino mixing matrix. It provides a natural framework of model building for the tri-bimaximal mixing matrix. In this class of models, it is necessary to have two Higgs fields, $\chi$ and $\chi'$, transforming under $A_4$ as 3 with one of them having vacuum expectation values for the three components to be equal and another having only one of the components to be non-zero. These specific vev structures require separating $\chi$ and $\chi'$ from communicating with each other. The clash of the different vev structures for $\chi$ and $\chi'$ is the so called sequestering problem. In this work, I show that it is possible to construct renormalizable supersymmetric models producing the tri-bimaximal neutrino mixing with no sequestering problem.
[ { "created": "Thu, 7 Dec 2006 10:50:45 GMT", "version": "v1" } ]
2008-11-26
[ [ "He", "Xiao-Gang", "", "NTU" ] ]
The tetrahedron $A_4$ group has been widely used in studying neutrino mixing matrix. It provides a natural framework of model building for the tri-bimaximal mixing matrix. In this class of models, it is necessary to have two Higgs fields, $\chi$ and $\chi'$, transforming under $A_4$ as 3 with one of them having vacuum expectation values for the three components to be equal and another having only one of the components to be non-zero. These specific vev structures require separating $\chi$ and $\chi'$ from communicating with each other. The clash of the different vev structures for $\chi$ and $\chi'$ is the so called sequestering problem. In this work, I show that it is possible to construct renormalizable supersymmetric models producing the tri-bimaximal neutrino mixing with no sequestering problem.
hep-ph/0402282
Masahide Yamaguchi
Masahide Yamaguchi and Jun'ichi Yokoyama
Smooth hybrid inflation in supergravity with a running spectral index and early star formation
12 pages, 1 figure, to appear in Phys. Rev. D
Phys.Rev.D70:023513,2004
10.1103/PhysRevD.70.023513
BROWN-HET-1397, OU-TAP-226
hep-ph astro-ph
null
It is shown that in a smooth hybrid inflation model in supergravity adiabatic fluctuations with a running spectral index with $\ns >1$ on a large scale and $\ns <1$ on a smaller scale can be naturally generated, as favored by the first-year data of WMAP. It is due to the balance between the nonrenormalizable term in the superpotential and the supergravity effect. However, since smooth hybrid inflation does not last long enough to reproduce the central value of observation, we invoke new inflation after the first inflation. Its initial condition is set dynamically during smooth hybrid inflation and the spectrum of fluctuations generated in this regime can have an appropriate shape to realize early star formation as found by WMAP. Hence two new features of WMAP observations are theoretically explained in a unified manner.
[ { "created": "Thu, 26 Feb 2004 22:23:31 GMT", "version": "v1" }, { "created": "Mon, 8 Mar 2004 18:52:51 GMT", "version": "v2" }, { "created": "Wed, 14 Jul 2004 08:21:07 GMT", "version": "v3" } ]
2009-06-19
[ [ "Yamaguchi", "Masahide", "" ], [ "Yokoyama", "Jun'ichi", "" ] ]
It is shown that in a smooth hybrid inflation model in supergravity adiabatic fluctuations with a running spectral index with $\ns >1$ on a large scale and $\ns <1$ on a smaller scale can be naturally generated, as favored by the first-year data of WMAP. It is due to the balance between the nonrenormalizable term in the superpotential and the supergravity effect. However, since smooth hybrid inflation does not last long enough to reproduce the central value of observation, we invoke new inflation after the first inflation. Its initial condition is set dynamically during smooth hybrid inflation and the spectrum of fluctuations generated in this regime can have an appropriate shape to realize early star formation as found by WMAP. Hence two new features of WMAP observations are theoretically explained in a unified manner.
2303.05492
Naoya Kitajima
Naoya Kitajima, Fuminobu Takahashi
Resonant production of dark photons from axion without a large coupling
16 pages, 5 figures
null
10.1103/PhysRevD.107.123518
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Dark photons could be produced resonantly by the oscillating axion field in the early universe. This resonant production mechanism has been used in various contexts, including dark photon dark matter and primordial magnetic field production. However, for this resonant production to work in an expanding universe, a large axion-dark photon coupling is required, which is not easy to realize in terms of model building and requires the introduction of many charged fermions and/or the complex clockwork mechanism. In this paper, we present a new scenario that efficiently produces dark photons from the axion with a much smaller coupling. This is possible by modifying the dynamics of axion and significantly delaying the onset of oscillations, as in the so-called trapped misalignment mechanism. As a specific example, we consider models in which dark photon production occurs efficiently despite the small axion-dark photon coupling by temporally trapping an axion in a wrong minimum and releasing it after the Hubble parameter becomes much smaller than the axion mass. In this scenario, it is expected that the polarization asymmetry of dark photons and gravitational waves generated from dark photons will be significantly reduced.
[ { "created": "Thu, 9 Mar 2023 18:47:17 GMT", "version": "v1" } ]
2023-06-28
[ [ "Kitajima", "Naoya", "" ], [ "Takahashi", "Fuminobu", "" ] ]
Dark photons could be produced resonantly by the oscillating axion field in the early universe. This resonant production mechanism has been used in various contexts, including dark photon dark matter and primordial magnetic field production. However, for this resonant production to work in an expanding universe, a large axion-dark photon coupling is required, which is not easy to realize in terms of model building and requires the introduction of many charged fermions and/or the complex clockwork mechanism. In this paper, we present a new scenario that efficiently produces dark photons from the axion with a much smaller coupling. This is possible by modifying the dynamics of axion and significantly delaying the onset of oscillations, as in the so-called trapped misalignment mechanism. As a specific example, we consider models in which dark photon production occurs efficiently despite the small axion-dark photon coupling by temporally trapping an axion in a wrong minimum and releasing it after the Hubble parameter becomes much smaller than the axion mass. In this scenario, it is expected that the polarization asymmetry of dark photons and gravitational waves generated from dark photons will be significantly reduced.
1801.05478
Feng Yuan
Bo-Wen Xiao, Feng Yuan
BFKL and Sudakov Resummation in Higgs Boson Plus Jet Production with Large Rapidity Separation
10 pages, 1 figure
null
10.1016/j.physletb.2018.04.070
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the QCD resummation for the Higgs boson plus a high $P_T$ jet production with large rapidity separations in proton-proton collisions at the LHC. The relevant Balitsky-Fadin-Kuraev-Lipatov (BFKL) and Sudakov logs are identified and resummed. In particular, we apply recent developments of the transverse momentum dependent factorization formalism in the impact factors, which provides a systematic framework to incorporate both the BFKL and Sudakov resummations.
[ { "created": "Tue, 16 Jan 2018 20:51:50 GMT", "version": "v1" } ]
2018-05-09
[ [ "Xiao", "Bo-Wen", "" ], [ "Yuan", "Feng", "" ] ]
We investigate the QCD resummation for the Higgs boson plus a high $P_T$ jet production with large rapidity separations in proton-proton collisions at the LHC. The relevant Balitsky-Fadin-Kuraev-Lipatov (BFKL) and Sudakov logs are identified and resummed. In particular, we apply recent developments of the transverse momentum dependent factorization formalism in the impact factors, which provides a systematic framework to incorporate both the BFKL and Sudakov resummations.
1506.09080
Raghunath Sahoo
Edward K.G. Sarkisyan, Aditya Nath Mishra, Raghunath Sahoo, and Alexander S. Sakharov
Multihadron production dynamics exploring the energy balance in hadronic and nuclear collisions
14 pages, 9 figures, Version similar to the published version in Phys. Rev. D, Fig. 1 caption has gone through minor changes
Phys. Rev. D 93, 054046 (2016)
10.1103/PhysRevD.93.054046
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The multihadron production in nucleus-nucleus collisions and its interrelation with that in (anti)proton-proton interactions are studied by exploring the charged particle mean multiplicity collision-energy and centrality dependencies in the measurements to date. The study is performed in the framework of the recently proposed effective-energy approach which, under the proper scaling of the collision energy, combines the constituent quark picture with Landau relativistic hydrodynamics counting for the centrality-defined effective energy of participants and relating different types of collisions. Within this approach, the multiplicity energy dependence and the pseudorapidity spectra from the most central nuclear collisions are well reproduced. The study of the multiplicity centrality dependence reveals a new scaling between the measured pseudorapidity spectra and the calculations. By means of this scaling, called the energy balanced limiting fragmentation scaling, one reproduces the pseudorapidity spectra for all centralities. The scaling elucidates some differences in the multiplicity and midrapidity density centrality dependence obtained at RHIC and LHC. These findings reveal an inherent similarity in the multiplicity energy dependence from the most central collisions and centrality data. A new regime in heavy-ion collisions to occur at about a TeV energy is indicated, similar to that observed in the earlier studies of the midrapidity densities. Predictions are made for the mean multiplicities to be measured in proton-proton and heavy-ion collisions at the LHC.
[ { "created": "Tue, 30 Jun 2015 13:34:42 GMT", "version": "v1" }, { "created": "Wed, 30 Mar 2016 18:05:36 GMT", "version": "v2" }, { "created": "Mon, 4 Apr 2016 13:17:00 GMT", "version": "v3" } ]
2016-04-05
[ [ "Sarkisyan", "Edward K. G.", "" ], [ "Mishra", "Aditya Nath", "" ], [ "Sahoo", "Raghunath", "" ], [ "Sakharov", "Alexander S.", "" ] ]
The multihadron production in nucleus-nucleus collisions and its interrelation with that in (anti)proton-proton interactions are studied by exploring the charged particle mean multiplicity collision-energy and centrality dependencies in the measurements to date. The study is performed in the framework of the recently proposed effective-energy approach which, under the proper scaling of the collision energy, combines the constituent quark picture with Landau relativistic hydrodynamics counting for the centrality-defined effective energy of participants and relating different types of collisions. Within this approach, the multiplicity energy dependence and the pseudorapidity spectra from the most central nuclear collisions are well reproduced. The study of the multiplicity centrality dependence reveals a new scaling between the measured pseudorapidity spectra and the calculations. By means of this scaling, called the energy balanced limiting fragmentation scaling, one reproduces the pseudorapidity spectra for all centralities. The scaling elucidates some differences in the multiplicity and midrapidity density centrality dependence obtained at RHIC and LHC. These findings reveal an inherent similarity in the multiplicity energy dependence from the most central collisions and centrality data. A new regime in heavy-ion collisions to occur at about a TeV energy is indicated, similar to that observed in the earlier studies of the midrapidity densities. Predictions are made for the mean multiplicities to be measured in proton-proton and heavy-ion collisions at the LHC.
2308.05215
Gabriele Levati
Luca Di Luzio, Gabriele Levati, Paride Paradisi, Xavier Ponce D\'iaz
Flavour constraints on light spin-1 bosons within a chiral Lagrangian approach
15 pages, 5 figures, 1 table
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We discuss the construction of the chiral Lagrangian for a light spin-1 boson, here denoted as $X$, featuring both vector and axial-vector couplings to light $u,d,s$ quarks. Focusing on $\Delta S = 1$ transitions, we show that there are model-independent tree-level contributions to $K^\pm \to \pi^\pm X$, sourced by Standard Model charged currents, which receive an $m^2_K / m_X^2$ enhancement from the emission of a longitudinally polarized $X$. This flavour observable sets the strongest to date model-independent bound on the diagonal axial-vector couplings of $X$ to $u,d,s$ quarks for $m_X < m_K - m_\pi$, superseding the bounds arising from beam-dump and collider searches.
[ { "created": "Wed, 9 Aug 2023 20:35:06 GMT", "version": "v1" } ]
2023-08-11
[ [ "Di Luzio", "Luca", "" ], [ "Levati", "Gabriele", "" ], [ "Paradisi", "Paride", "" ], [ "Díaz", "Xavier Ponce", "" ] ]
We discuss the construction of the chiral Lagrangian for a light spin-1 boson, here denoted as $X$, featuring both vector and axial-vector couplings to light $u,d,s$ quarks. Focusing on $\Delta S = 1$ transitions, we show that there are model-independent tree-level contributions to $K^\pm \to \pi^\pm X$, sourced by Standard Model charged currents, which receive an $m^2_K / m_X^2$ enhancement from the emission of a longitudinally polarized $X$. This flavour observable sets the strongest to date model-independent bound on the diagonal axial-vector couplings of $X$ to $u,d,s$ quarks for $m_X < m_K - m_\pi$, superseding the bounds arising from beam-dump and collider searches.
0711.2184
Markus Diehl
Markus Diehl and Wolfgang Kugler
Some numerical studies of the evolution of generalized parton distributions
12 pages, 12 figures. v2: added comments on power-law behavior
Phys.Lett.B660:202-211,2008
10.1016/j.physletb.2007.12.047
DESY 07-195
hep-ph
null
We study the evolution behavior of generalized parton distributions at small longitudinal momentum fraction. Particular attention is paid to the ratio of a generalized parton distribution and its forward limit, to the mixing between quarks and gluons, and to the dependence on the squared momentum transfer t.
[ { "created": "Wed, 14 Nov 2007 13:06:42 GMT", "version": "v1" }, { "created": "Tue, 8 Jan 2008 15:24:34 GMT", "version": "v2" } ]
2008-11-26
[ [ "Diehl", "Markus", "" ], [ "Kugler", "Wolfgang", "" ] ]
We study the evolution behavior of generalized parton distributions at small longitudinal momentum fraction. Particular attention is paid to the ratio of a generalized parton distribution and its forward limit, to the mixing between quarks and gluons, and to the dependence on the squared momentum transfer t.
1005.1010
Eef van Beveren
Eef van Beveren, George Rupp and J. Segovia
A very broad X(4260) and the resonance parameters of the 3D vector charmonium state
4 pages, 5 figures; version 2: 2 figures replaced
Phys.Rev.Lett.105:102001,2010
10.1103/PhysRevLett.105.102001
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the X(4260) enhancement contains a wealth of information on vector c-cbar spectroscopy. We discuss the shape of the X(4260) observed in the OZI-forbidden process "electron-positron into J/psi and a pair of charged pions", in particular at and near vector charmonium resonances as well as open-charm threshold enhancements. The resulting very broad X(4260) structure does not seem to classify itself as a vector charmonium resonance, but its detailed shape allows to identify new vector c-cbar states. Here, we estimate the resonance parameters of the psi(3D) state.
[ { "created": "Thu, 6 May 2010 14:34:01 GMT", "version": "v1" }, { "created": "Fri, 7 May 2010 05:13:56 GMT", "version": "v2" } ]
2014-11-21
[ [ "van Beveren", "Eef", "" ], [ "Rupp", "George", "" ], [ "Segovia", "J.", "" ] ]
We argue that the X(4260) enhancement contains a wealth of information on vector c-cbar spectroscopy. We discuss the shape of the X(4260) observed in the OZI-forbidden process "electron-positron into J/psi and a pair of charged pions", in particular at and near vector charmonium resonances as well as open-charm threshold enhancements. The resulting very broad X(4260) structure does not seem to classify itself as a vector charmonium resonance, but its detailed shape allows to identify new vector c-cbar states. Here, we estimate the resonance parameters of the psi(3D) state.
1303.3282
Wynn C. G. Ho
Wynn C. G. Ho, Nils Andersson, Cristobal M. Espinoza, Kostas Glampedakis, Brynmor Haskell, and Craig O. Heinke
The hottest superfluid and superconductor in the Universe: Discovery and nuclear physics implications
8 pages, 4 figures; Proceedings of Xth Quark Confinement and the Hadron Spectrum, M. Berwein, N. Brambilla, S. Paul (eds.); v2 same as v1; correction to editor list
PoS (Confinement X) 260 (2013)
null
null
hep-ph astro-ph.SR nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present recent work on using astronomical observations of neutron stars to reveal unique insights into nuclear matter that cannot be obtained from laboratories on Earth. First, we discuss our measurement of the rapid cooling of the youngest neutron star in the Galaxy; this provides the first direct evidence for superfluidity and superconductivity in the supra-nuclear core of neutron stars. We show that observations of thermonuclear X-ray bursts on neutron stars can be used to constrain properties of neutron superfluidity and neutrino emission. We describe the implications of rapid neutron star rotation rates on aspects of nuclear and superfluid physics. Finally, we show that entrainment coupling between the neutron superfluid and the nuclear lattice leads to a less mobile crust superfluid; this result puts into question the conventional picture of pulsar glitches as being solely due to the crust superfluid and suggests that the core superfluid also participates.
[ { "created": "Wed, 13 Mar 2013 20:23:06 GMT", "version": "v1" }, { "created": "Fri, 15 Mar 2013 13:17:29 GMT", "version": "v2" } ]
2013-03-18
[ [ "Ho", "Wynn C. G.", "" ], [ "Andersson", "Nils", "" ], [ "Espinoza", "Cristobal M.", "" ], [ "Glampedakis", "Kostas", "" ], [ "Haskell", "Brynmor", "" ], [ "Heinke", "Craig O.", "" ] ]
We present recent work on using astronomical observations of neutron stars to reveal unique insights into nuclear matter that cannot be obtained from laboratories on Earth. First, we discuss our measurement of the rapid cooling of the youngest neutron star in the Galaxy; this provides the first direct evidence for superfluidity and superconductivity in the supra-nuclear core of neutron stars. We show that observations of thermonuclear X-ray bursts on neutron stars can be used to constrain properties of neutron superfluidity and neutrino emission. We describe the implications of rapid neutron star rotation rates on aspects of nuclear and superfluid physics. Finally, we show that entrainment coupling between the neutron superfluid and the nuclear lattice leads to a less mobile crust superfluid; this result puts into question the conventional picture of pulsar glitches as being solely due to the crust superfluid and suggests that the core superfluid also participates.
hep-ph/0301211
Yvonne Wong
C. N. Leung, Yvonne Y. Y. Wong
T-violation in flavour oscillations as a test for relativity principles at a neutrino factory
RevTeX4, 10 pages, 11 figures; To appear in PRD; v2: two references added
Phys.Rev.D67:056005,2003
10.1103/PhysRevD.67.056005
null
hep-ph
null
We study the effects of violation of the equivalence principle (VEP) or violation of Lorentz invariance (LIV) in the neutrino sector on the asymmetry between T-conjugate oscillation probabilities, $\Delta P_T \equiv P(\nu_{\alpha} \to \nu_{\beta}) - P(\nu_{\beta} \to \nu_{\alpha})$, in a three-flavour framework. We find that additional mixing due to these mechanisms, while obeying all present bounds, can lead to an observable enhancement, suppression, and/or sign change in $\Delta P_T$ for the preferred energies and baselines of a neutrino factory. The measurement of this asymmetry can be used to establish a new upper limit of order $10^{-26}$ on VEP or LIV in the $(\nu_e, \nu_\mu)$ and $(\nu_e, \nu_\tau)$ sectors.
[ { "created": "Thu, 23 Jan 2003 19:43:38 GMT", "version": "v1" }, { "created": "Wed, 5 Feb 2003 00:25:56 GMT", "version": "v2" } ]
2008-11-26
[ [ "Leung", "C. N.", "" ], [ "Wong", "Yvonne Y. Y.", "" ] ]
We study the effects of violation of the equivalence principle (VEP) or violation of Lorentz invariance (LIV) in the neutrino sector on the asymmetry between T-conjugate oscillation probabilities, $\Delta P_T \equiv P(\nu_{\alpha} \to \nu_{\beta}) - P(\nu_{\beta} \to \nu_{\alpha})$, in a three-flavour framework. We find that additional mixing due to these mechanisms, while obeying all present bounds, can lead to an observable enhancement, suppression, and/or sign change in $\Delta P_T$ for the preferred energies and baselines of a neutrino factory. The measurement of this asymmetry can be used to establish a new upper limit of order $10^{-26}$ on VEP or LIV in the $(\nu_e, \nu_\mu)$ and $(\nu_e, \nu_\tau)$ sectors.
1212.3732
Anatoly Kotikov Vassilievich
A. V. Kotikov
The property of maximal transcendentality: calculation of master integrals
12 pages, 3 figures, talk given at the IV International Conference "Models in Quantum Field Theory" (MQFT-2012), September 24-27, 2012, V.A. Fock Physical Research Institute, Petergof, Russia
null
10.1007/s11232-013-0079-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the results having the property of maximal transcendentality.
[ { "created": "Sat, 15 Dec 2012 21:26:29 GMT", "version": "v1" } ]
2015-06-12
[ [ "Kotikov", "A. V.", "" ] ]
We review the results having the property of maximal transcendentality.
hep-ph/9905218
Francesco Hautmann
F. Hautmann, Z. Kunszt and D.E. Soper
Hard diffraction from small-size color sources
6 pages, 5 figures, talk presented at DPF '99
null
null
null
hep-ph
null
We describe diffractive hard processes in the framework of QCD factorization and discuss what one can learn from the study of hadronic systems with small transverse size.
[ { "created": "Mon, 3 May 1999 21:42:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hautmann", "F.", "" ], [ "Kunszt", "Z.", "" ], [ "Soper", "D. E.", "" ] ]
We describe diffractive hard processes in the framework of QCD factorization and discuss what one can learn from the study of hadronic systems with small transverse size.
1603.05388
Li-Sheng Geng
Jun-Xu Lu, Hua-Xing Chen, Zhi-Hui Guo, J. Nieves, Ju-Jun Xie, Li-Sheng Geng
The $\Lambda_c(2595)$ resonance as a dynamically generated state: the compositeness condition and the large $N_c$ evolution
33 pages, 2 figures
Phys. Rev. D 93, 114028 (2016)
10.1103/PhysRevD.93.114028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent studies have shown that the well established $\Lambda_c(2595)$ resonance contains a large meson-baryon component, which can vary depending on the specific formalism. In this work, we examine such a picture by utilizing the compositeness condition and the large number of colors ($N_c$) expansion. We examine three different models fulfilling two body unitarity in coupled-channels, and adopting renormalization schemes where the mass of the $\Lambda_c(2595)$ resonance is well described, but not necessarily its width, since we do not consider three body channels and work at the isospin symmetric limit. Both approximations might have an effect larger on the width than on the mass. In this context, our studies show that the compositeness of the $\Lambda_c(2595)$ depends on the number of considered coupled channels, and on the particular regularization scheme adopted in the unitary approaches and, therefore, is model dependent. In addition, we perform an exploratory study of the $\Lambda_c(2595)$ in the large $N_c$ expansion, within a scheme involving only the $\pi\Sigma_c$ and $K\Xi'_c$ channels, whose dynamics is mostly fixed by chiral symmetry. In this context and formulating the leading-order interaction as a function of $N_c$, we show that for moderate $N_c> 3$ values, the mass and width of the $\Lambda_c(2595)$ deviate from those of a genuine $qqq$ baryon, implying the relevance of meson-baryon components in its wave function. Furthermore, we study the properties of the $\Lambda_c(2595)$, in the strict $N_c \to \infty $ limit, using an extension of the chiral Weinberg-Tomozawa interaction to an arbitrary number of flavors and colors. This latter study hints at the possible existence of a (perhaps) sub-dominant $qqq$ component in the $\Lambda_c(2595)$ resonance wave function, which would become dominant when the number of colors gets sufficiently large.
[ { "created": "Thu, 17 Mar 2016 08:31:30 GMT", "version": "v1" } ]
2016-06-29
[ [ "Lu", "Jun-Xu", "" ], [ "Chen", "Hua-Xing", "" ], [ "Guo", "Zhi-Hui", "" ], [ "Nieves", "J.", "" ], [ "Xie", "Ju-Jun", "" ], [ "Geng", "Li-Sheng", "" ] ]
Recent studies have shown that the well established $\Lambda_c(2595)$ resonance contains a large meson-baryon component, which can vary depending on the specific formalism. In this work, we examine such a picture by utilizing the compositeness condition and the large number of colors ($N_c$) expansion. We examine three different models fulfilling two body unitarity in coupled-channels, and adopting renormalization schemes where the mass of the $\Lambda_c(2595)$ resonance is well described, but not necessarily its width, since we do not consider three body channels and work at the isospin symmetric limit. Both approximations might have an effect larger on the width than on the mass. In this context, our studies show that the compositeness of the $\Lambda_c(2595)$ depends on the number of considered coupled channels, and on the particular regularization scheme adopted in the unitary approaches and, therefore, is model dependent. In addition, we perform an exploratory study of the $\Lambda_c(2595)$ in the large $N_c$ expansion, within a scheme involving only the $\pi\Sigma_c$ and $K\Xi'_c$ channels, whose dynamics is mostly fixed by chiral symmetry. In this context and formulating the leading-order interaction as a function of $N_c$, we show that for moderate $N_c> 3$ values, the mass and width of the $\Lambda_c(2595)$ deviate from those of a genuine $qqq$ baryon, implying the relevance of meson-baryon components in its wave function. Furthermore, we study the properties of the $\Lambda_c(2595)$, in the strict $N_c \to \infty $ limit, using an extension of the chiral Weinberg-Tomozawa interaction to an arbitrary number of flavors and colors. This latter study hints at the possible existence of a (perhaps) sub-dominant $qqq$ component in the $\Lambda_c(2595)$ resonance wave function, which would become dominant when the number of colors gets sufficiently large.
1503.01325
Patrick Janot
Patrick Janot
Top-quark electroweak couplings at the FCC-ee
18 pages, 5 figures. To be published in JHEP (accepted for publication). Between version 2 and version 3, the suggestions of the JHEP referee were implemented both in the text (in Sections "Results and discussion" and "Summary and outlook") and in Figures 3 and 5
null
10.1007/JHEP04(2015)182
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An optimal-observable analysis of the lepton angular and energy distributions from top-quark pair production with semi-leptonic decays in e+e- collisions is used to predict the potential sensitivity of the FCC-ee to the couplings of the top quark to the photon and the Z.
[ { "created": "Wed, 4 Mar 2015 14:53:07 GMT", "version": "v1" }, { "created": "Wed, 11 Mar 2015 10:45:29 GMT", "version": "v2" }, { "created": "Tue, 14 Apr 2015 08:27:34 GMT", "version": "v3" } ]
2015-06-11
[ [ "Janot", "Patrick", "" ] ]
An optimal-observable analysis of the lepton angular and energy distributions from top-quark pair production with semi-leptonic decays in e+e- collisions is used to predict the potential sensitivity of the FCC-ee to the couplings of the top quark to the photon and the Z.
0809.2472
Andrei Leonidov
I.M. Dremin, M.R. Kirakosyan, A.V. Leonidov, A.V. Vinogradov
Cherenkov Glue in Opaque Nuclear Medium
null
Nucl.Phys.A826:190-197,2009
10.1016/j.nuclphysa.2009.05.003
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectrum of Cherenkov gluons is calculated within the framework of in-medium QCD. It is compared with experimental data on the double-humped structure around the away-side jet obtained at RHIC. The values of the real and imaginary parts of the nuclear permittivity are obtained from these fits. It is shown that accounting for an additional smearing due to resonance-like production of final hadrons allows to achieve an agreement with experimental data.
[ { "created": "Mon, 15 Sep 2008 10:03:27 GMT", "version": "v1" }, { "created": "Mon, 22 Sep 2008 17:36:08 GMT", "version": "v2" }, { "created": "Wed, 24 Sep 2008 03:27:42 GMT", "version": "v3" }, { "created": "Fri, 22 May 2009 11:34:43 GMT", "version": "v4" } ]
2010-06-03
[ [ "Dremin", "I. M.", "" ], [ "Kirakosyan", "M. R.", "" ], [ "Leonidov", "A. V.", "" ], [ "Vinogradov", "A. V.", "" ] ]
The spectrum of Cherenkov gluons is calculated within the framework of in-medium QCD. It is compared with experimental data on the double-humped structure around the away-side jet obtained at RHIC. The values of the real and imaginary parts of the nuclear permittivity are obtained from these fits. It is shown that accounting for an additional smearing due to resonance-like production of final hadrons allows to achieve an agreement with experimental data.
hep-ph/0410337
Yong-Yeon Keum
Yong-Yeon Keum
Phenomenological Application of $k_T$ factorization
26 pages with revtex4, 13 figures; Added references and corrected typos. Invited plenary talk at the Workshop on High Energy Physics Phenomenology (WHEPP8) India, Institute of Technology, Mumbai (India) January 5-16,2004; To be published in PRAMANA, journal of physics Dec. 2004, Indian Academy of Sciences
Pramana63:1151-1170,2004
10.1007/BF02704888
null
hep-ph hep-ex
null
We discuss applications of the perturbative QCD approach in the exclusive non-leptonic two body B-meson decays. We briefly review its ingredients and some important theoretical issues on the factorization approaches. PQCD results are compatible with present experimantal data for the charmless B-meson decays. We predict the possibility of large direct CP asymmetry in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm7 %)$ and $B^0\to K^{+}\pi^{-}$ $(-17\pm5%)$. We also investigate the Branching ratios, CP asymmetry and isopsin symmetry breaking in radiative $B \to (K^*/\rho) \gamma$ decays.
[ { "created": "Mon, 25 Oct 2004 17:12:30 GMT", "version": "v1" }, { "created": "Thu, 25 Nov 2004 19:16:49 GMT", "version": "v2" } ]
2008-11-26
[ [ "Keum", "Yong-Yeon", "" ] ]
We discuss applications of the perturbative QCD approach in the exclusive non-leptonic two body B-meson decays. We briefly review its ingredients and some important theoretical issues on the factorization approaches. PQCD results are compatible with present experimantal data for the charmless B-meson decays. We predict the possibility of large direct CP asymmetry in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm7 %)$ and $B^0\to K^{+}\pi^{-}$ $(-17\pm5%)$. We also investigate the Branching ratios, CP asymmetry and isopsin symmetry breaking in radiative $B \to (K^*/\rho) \gamma$ decays.