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hep-ph/9507242
Andre Likhoded
A.V.Berezhnoy, V.V.Kiselev, A.K.Likhoded
Hadronic production of baryons, containing two heavy quarks
7 pages, LATEX file and tar-compressed uuencoded figures
Phys.Atom.Nucl. 59 (1996) 870-874; Yad.Fiz. 59 (1996) 909-913
null
IHEP 95-87, Protvino, Russia
hep-ph
null
In the framework of QCD perturbation theory, total and differential cross sections of the $\Xi_{bc}'$, $\Xi_{bc}^{(*)}$ and $\Xi_{cc}^{(*)}$ baryons production in gluon collisions are calculated in the leading order over $\alpha_s$ for the doubly heavy ($b c$) and ($ c c$) diquarks. At both small and large transverse momenta of the baryons, a use of the mechanism of the heavy quark fragmentation into the heavy diquark is shown to underestimate the cross section values in comparison with the exact numerical calculations of complete set of diagrams. The expected in Tevatron experiments yield of baryons with two heavy quarks is evaluated as $(1.3\pm 0.3) \cdot 10^5 \,\, bcq$-baryons and $(1.6\pm 0.3) \cdot 10^4 \,\, ccq$-baryons at $p_T>5$ GeV and $|y|<1$ of the baryon momentum and rapidity cuts, with account for the antiparticle yields.
[ { "created": "Thu, 6 Jul 1995 12:12:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Berezhnoy", "A. V.", "" ], [ "Kiselev", "V. V.", "" ], [ "Likhoded", "A. K.", "" ] ]
In the framework of QCD perturbation theory, total and differential cross sections of the $\Xi_{bc}'$, $\Xi_{bc}^{(*)}$ and $\Xi_{cc}^{(*)}$ baryons production in gluon collisions are calculated in the leading order over $\alpha_s$ for the doubly heavy ($b c$) and ($ c c$) diquarks. At both small and large transverse momenta of the baryons, a use of the mechanism of the heavy quark fragmentation into the heavy diquark is shown to underestimate the cross section values in comparison with the exact numerical calculations of complete set of diagrams. The expected in Tevatron experiments yield of baryons with two heavy quarks is evaluated as $(1.3\pm 0.3) \cdot 10^5 \,\, bcq$-baryons and $(1.6\pm 0.3) \cdot 10^4 \,\, ccq$-baryons at $p_T>5$ GeV and $|y|<1$ of the baryon momentum and rapidity cuts, with account for the antiparticle yields.
0911.4634
B. L. G. Bakker
A.M. Badalian, B.L.G. Bakker, I.V. Danilkin
The Hyperfine Splittings in Bottomonium and the $B_q (q=n,s,c)$ Mesons
5 pages revtex4
Phys.Rev.D81:071502,2010; Erratum-ibid.D81:099902,2010
10.1103/PhysRevD.81.071502 10.1103/PhysRevD.81.099902
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A universal description of the hyperfine splittings (HFS) in bottomonium and the $B_q (q=n,s,c)$ mesons is obtained with a universal strong coupling constant $\alpha_s(\mu)=0.305(2)$ in a spin-spin potential. Other characteristics are calculated within the Field Correlator Method, taking the freezing value of the strong coupling independent of $n_f$. The HFS $M(B^*)- M(B)=45.3(3)$ MeV, $M(B_s^*) - M(B_s)=46.5(3)$ MeV are obtained in full agreement with experiment both for $n_f=3$ and $n_f=4$. In bottomonium, $M(\Upsilon(9460))- M(\eta_b)=70.0(4)$ MeV for $n_f=5$ agrees with the BaBar data, while a smaller HFS, equal to 64(1) MeV, is obtained for $n_f=4$. We predict HFS $M(\Upsilon(2S))-M(\eta_b(2S))=36(1)$ MeV, $M(\Upsilon(3S))- M(\eta(3S))=27(1)$ MeV, and $M(B_c^*) - M(B_c)= 57.5(10)$ MeV, which gives $M(B_c^*)=6334(1)$ MeV, $M(B_c(2 {}^1S_0))=6865(5)$ MeV, and $M(B_c^*(2S {}^3S_1))=6901(5)$ MeV.
[ { "created": "Tue, 24 Nov 2009 14:00:56 GMT", "version": "v1" }, { "created": "Fri, 12 Mar 2010 13:19:39 GMT", "version": "v2" } ]
2014-11-20
[ [ "Badalian", "A. M.", "" ], [ "Bakker", "B. L. G.", "" ], [ "Danilkin", "I. V.", "" ] ]
A universal description of the hyperfine splittings (HFS) in bottomonium and the $B_q (q=n,s,c)$ mesons is obtained with a universal strong coupling constant $\alpha_s(\mu)=0.305(2)$ in a spin-spin potential. Other characteristics are calculated within the Field Correlator Method, taking the freezing value of the strong coupling independent of $n_f$. The HFS $M(B^*)- M(B)=45.3(3)$ MeV, $M(B_s^*) - M(B_s)=46.5(3)$ MeV are obtained in full agreement with experiment both for $n_f=3$ and $n_f=4$. In bottomonium, $M(\Upsilon(9460))- M(\eta_b)=70.0(4)$ MeV for $n_f=5$ agrees with the BaBar data, while a smaller HFS, equal to 64(1) MeV, is obtained for $n_f=4$. We predict HFS $M(\Upsilon(2S))-M(\eta_b(2S))=36(1)$ MeV, $M(\Upsilon(3S))- M(\eta(3S))=27(1)$ MeV, and $M(B_c^*) - M(B_c)= 57.5(10)$ MeV, which gives $M(B_c^*)=6334(1)$ MeV, $M(B_c(2 {}^1S_0))=6865(5)$ MeV, and $M(B_c^*(2S {}^3S_1))=6901(5)$ MeV.
hep-ph/9509412
Yuping Kuang
Chong-Xing Yue, Yu-Ping Kuang, Gong-Ru Lu
Multiscale Technicolor and the Zbb-bar Vertex
9-page LaTex file
J.Phys.G23:163-168,1997
10.1088/0954-3899/23/2/004
TUIMP-TH-95/72
hep-ph
null
We estimate the correction to the Zbb-bar vertex arising from the exchanges of the sideways extended technicolor (ETC) boson and the flavor-diagonal ETC boson in the multiscale walking technicolor model. The obtained result is too large to explain the present data. However, if we introduce a new self- interaction for the top quark to induce the top quark condensate serving as the origin of the large top quark mass, the corrected R_b=Gamma_b/Gamma_h can be consistent with the recent LEP data. The corresponding correction to R_c=Gamma_c/Gamma_h is shown to be negligibly small.
[ { "created": "Thu, 28 Sep 1995 09:03:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Yue", "Chong-Xing", "" ], [ "Kuang", "Yu-Ping", "" ], [ "Lu", "Gong-Ru", "" ] ]
We estimate the correction to the Zbb-bar vertex arising from the exchanges of the sideways extended technicolor (ETC) boson and the flavor-diagonal ETC boson in the multiscale walking technicolor model. The obtained result is too large to explain the present data. However, if we introduce a new self- interaction for the top quark to induce the top quark condensate serving as the origin of the large top quark mass, the corrected R_b=Gamma_b/Gamma_h can be consistent with the recent LEP data. The corresponding correction to R_c=Gamma_c/Gamma_h is shown to be negligibly small.
hep-ph/0501060
Gilberto Tavares-Velasco
A. Cordero-Cid, J. L. Garcia-Luna, F. Ramirez-Zavaleta, G. Tavares-Velasco, J.J. Toscano
Rare three-body decay t -> c h gamma in the standard model and the two-Higgs doublet model
Updated to match published version
J.Phys. G32 (2006) 529-546
10.1088/0954-3899/32/4/010
null
hep-ph
null
A complete calculation of the rare three-body decay t --> c h gamma is presented in the framework of the standard model. In the unitary gauge, such a calculation involves about 20 Feynman diagrams. We also calculate this decay in the general two-Higgs doublet model (model III), in which it arises at the tree-level. While in the standard model the decay t --> c h gamma is extremely suppressed, with a branching fraction of the order of $10^{-15}$ for a Higgs boson mass of the order of 115 GeV, in the model III it may have a branching ratio up to $10^{-5}$. We also discuss the crossed decay h --> b \bar{s} gamma.
[ { "created": "Sun, 9 Jan 2005 04:34:36 GMT", "version": "v1" }, { "created": "Thu, 13 Jan 2005 17:24:01 GMT", "version": "v2" }, { "created": "Tue, 28 Feb 2006 06:57:20 GMT", "version": "v3" } ]
2007-05-23
[ [ "Cordero-Cid", "A.", "" ], [ "Garcia-Luna", "J. L.", "" ], [ "Ramirez-Zavaleta", "F.", "" ], [ "Tavares-Velasco", "G.", "" ], [ "Toscano", "J. J.", "" ] ]
A complete calculation of the rare three-body decay t --> c h gamma is presented in the framework of the standard model. In the unitary gauge, such a calculation involves about 20 Feynman diagrams. We also calculate this decay in the general two-Higgs doublet model (model III), in which it arises at the tree-level. While in the standard model the decay t --> c h gamma is extremely suppressed, with a branching fraction of the order of $10^{-15}$ for a Higgs boson mass of the order of 115 GeV, in the model III it may have a branching ratio up to $10^{-5}$. We also discuss the crossed decay h --> b \bar{s} gamma.
1302.1060
Antonio Delgado
Alfredo Aranda, Cesar Bonilla, Francisco de Anda, Antonio Delgado and Jaime Hern\'andez-S\'anchez
Higgs decay into two photons from a 3HDM with flavor symmetry
4 pages, 3 figures, version to be published in PLB
Phys.Lett.B725:97-100 (2013)
10.1016/j.physletb.2013.06.047
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this short letter we show that the excess of events in the decay of Higgs to two photons reported by ATLAS and CMS can be easily accommodated in a flavor renormalizable three Higgs doublet model (3HDM). The model is consistent with all fermion masses, mixing angles, and flavor changing neutral current constraints.
[ { "created": "Tue, 5 Feb 2013 15:12:10 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2013 04:44:20 GMT", "version": "v2" } ]
2014-01-24
[ [ "Aranda", "Alfredo", "" ], [ "Bonilla", "Cesar", "" ], [ "de Anda", "Francisco", "" ], [ "Delgado", "Antonio", "" ], [ "Hernández-Sánchez", "Jaime", "" ] ]
In this short letter we show that the excess of events in the decay of Higgs to two photons reported by ATLAS and CMS can be easily accommodated in a flavor renormalizable three Higgs doublet model (3HDM). The model is consistent with all fermion masses, mixing angles, and flavor changing neutral current constraints.
hep-ph/9801300
Gaby Raedel
A. De Roeck (DESY,CERN), A. Deshpande (Yale), V. W. Hughes (Yale), J. Lichtenstadt (Tel Aviv), G. Radel (CERN)
A Study of the Polarized Structure Function g_1^p(x,Q^2) and the Polarized Gluon Distribution Delta g(x,Q^2) at HERA
20 pages including 7 figures, references added, discussion on systematic errors expanded, version to appear in Eur.Phys.J.C
Eur.Phys.J.C6:121-131,1999
10.1007/s100520050325
DESY 97-249
hep-ph
null
We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show that these data will provide important information on the low-x behavior of the polarized structure function g_1, and will reduce the uncertainty in the determination of the first moment of the polarized gluon distribution Delta g(x,Q^2) obtained from the QCD analysis of g_1 in NLO. Furthermore, using asymmetries for di-jet events from a polarized HERA would substantially reduce the uncertainty in the shape of Delta g(x,Q^2). Using the information on Delta g(x,Q^2) from the di-jet analysis in conjunction with the NLO QCD analysis of g_1 will provide an accurate determination of Delta g(x,Q^2) and its first moment.
[ { "created": "Wed, 14 Jan 1998 15:04:02 GMT", "version": "v1" }, { "created": "Mon, 20 Apr 1998 14:08:09 GMT", "version": "v2" } ]
2011-09-13
[ [ "De Roeck", "A.", "", "DESY,CERN" ], [ "Deshpande", "A.", "", "Yale" ], [ "Hughes", "V. W.", "", "Yale" ], [ "Lichtenstadt", "J.", "", "Tel Aviv" ], [ "Radel", "G.", "", "CERN" ] ]
We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show that these data will provide important information on the low-x behavior of the polarized structure function g_1, and will reduce the uncertainty in the determination of the first moment of the polarized gluon distribution Delta g(x,Q^2) obtained from the QCD analysis of g_1 in NLO. Furthermore, using asymmetries for di-jet events from a polarized HERA would substantially reduce the uncertainty in the shape of Delta g(x,Q^2). Using the information on Delta g(x,Q^2) from the di-jet analysis in conjunction with the NLO QCD analysis of g_1 will provide an accurate determination of Delta g(x,Q^2) and its first moment.
hep-ph/9606219
null
P.Colangelo, F.De Fazio, G.Nardulli
On the Decay Mode $B^- \to \mu^- \bar \nu_\mu \gamma$
LaTex, 9 pages, 2 uuencoded postscript figures
Phys.Lett.B386:328-334,1996
10.1016/0370-2693(96)00955-0
BARI-TH/96-235
hep-ph
null
A QCD relativistic potential model is employed to compute the decay rate and the photon spectrum of the process $B^- \to \mu^- {\bar \nu}_\mu \gamma$. The result ${\cal B}(B^- \to \mu^- {\bar \nu}_\mu \gamma) \simeq 1 \times 10^{-6}$ confirms the enhancement of this decay channel with respect to the purely leptonic mode, and supports the proposal of using this process to access relevant hadronic quantities such as the $B$-meson leptonic decay constant and the CKM matrix element $V_{ub}$.
[ { "created": "Tue, 4 Jun 1996 11:29:46 GMT", "version": "v1" } ]
2010-11-23
[ [ "Colangelo", "P.", "" ], [ "De Fazio", "F.", "" ], [ "Nardulli", "G.", "" ] ]
A QCD relativistic potential model is employed to compute the decay rate and the photon spectrum of the process $B^- \to \mu^- {\bar \nu}_\mu \gamma$. The result ${\cal B}(B^- \to \mu^- {\bar \nu}_\mu \gamma) \simeq 1 \times 10^{-6}$ confirms the enhancement of this decay channel with respect to the purely leptonic mode, and supports the proposal of using this process to access relevant hadronic quantities such as the $B$-meson leptonic decay constant and the CKM matrix element $V_{ub}$.
2205.00942
Valerie Fiona Domcke
Valerie Domcke, Keisuke Harigaya and Kyohei Mukaida
Charge transfer between rotating complex scalar fields
31 pages, 7 figures
null
10.1007/JHEP08(2022)234
CERN-TH-2022-075, KEK-TH-2422
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We consider the transfer of a U(1) charge density between Bose-Einstein condensates of complex scalar fields coupled to a thermal bath, focusing on the case of a homogeneous Affleck-Dine field transmitting the charge stored in its angular motion to an axion field. We demonstrate that in the absence of additional symmetries this charge transfer, aided by cosmic expansion as well as the thermal effective potential of the Affleck-Dine field, can be very efficient. The charge redistribution between the scalar fields becomes possible if the interactions with the thermal bath break the original U(1) x U(1) symmetry down to a single U(1) symmetry; the charge distribution between the two fields is then determined by minimizing the free energy. We discuss implications for cosmological setups involving complex scalars, with applications to axion dark matter, baryogenesis, kination domination, and gravitational wave production.
[ { "created": "Mon, 2 May 2022 14:41:12 GMT", "version": "v1" } ]
2022-09-07
[ [ "Domcke", "Valerie", "" ], [ "Harigaya", "Keisuke", "" ], [ "Mukaida", "Kyohei", "" ] ]
We consider the transfer of a U(1) charge density between Bose-Einstein condensates of complex scalar fields coupled to a thermal bath, focusing on the case of a homogeneous Affleck-Dine field transmitting the charge stored in its angular motion to an axion field. We demonstrate that in the absence of additional symmetries this charge transfer, aided by cosmic expansion as well as the thermal effective potential of the Affleck-Dine field, can be very efficient. The charge redistribution between the scalar fields becomes possible if the interactions with the thermal bath break the original U(1) x U(1) symmetry down to a single U(1) symmetry; the charge distribution between the two fields is then determined by minimizing the free energy. We discuss implications for cosmological setups involving complex scalars, with applications to axion dark matter, baryogenesis, kination domination, and gravitational wave production.
hep-ph/0106007
Fulvia De Fazio
Fulvia De Fazio
Highlights in the analysis of exclusive B decays
LaTex, 5 pages. Invited talk at the XIII Italian meeting on the Physics at LEP "LEPTRE", Rome April 18-20 2001, to appear in the proceedings. One reference added
null
null
BARI-TH/417-2001
hep-ph
null
I briefly describe recent developments in the theoretical analysis of non leptonic and semileptonic B decays. For non leptonic transitions, I focus on factorization, from the naive formulation to the most recent achievements. As for semileptonic decays, I mainly consider B transitions to excited charmed states.
[ { "created": "Fri, 1 Jun 2001 11:03:57 GMT", "version": "v1" }, { "created": "Tue, 31 Jul 2001 13:23:25 GMT", "version": "v2" } ]
2007-05-23
[ [ "De Fazio", "Fulvia", "" ] ]
I briefly describe recent developments in the theoretical analysis of non leptonic and semileptonic B decays. For non leptonic transitions, I focus on factorization, from the naive formulation to the most recent achievements. As for semileptonic decays, I mainly consider B transitions to excited charmed states.
2210.11489
Yifeng Huang
Jack H. Collins, Yifeng Huang, Simon Knapen, Benjamin Nachman, Daniel Whiteson
Machine-Learning Compression for Particle Physics Discoveries
9 pages, 3 figures
null
null
SLAC-PUB-17704
hep-ph cs.LG hep-ex physics.data-an
http://creativecommons.org/licenses/by/4.0/
In collider-based particle and nuclear physics experiments, data are produced at such extreme rates that only a subset can be recorded for later analysis. Typically, algorithms select individual collision events for preservation and store the complete experimental response. A relatively new alternative strategy is to additionally save a partial record for a larger subset of events, allowing for later specific analysis of a larger fraction of events. We propose a strategy that bridges these paradigms by compressing entire events for generic offline analysis but at a lower fidelity. An optimal-transport-based $\beta$ Variational Autoencoder (VAE) is used to automate the compression and the hyperparameter $\beta$ controls the compression fidelity. We introduce a new approach for multi-objective learning functions by simultaneously learning a VAE appropriate for all values of $\beta$ through parameterization. We present an example use case, a di-muon resonance search at the Large Hadron Collider (LHC), where we show that simulated data compressed by our $\beta$-VAE has enough fidelity to distinguish distinct signal morphologies.
[ { "created": "Thu, 20 Oct 2022 18:00:04 GMT", "version": "v1" }, { "created": "Sun, 18 Dec 2022 22:33:13 GMT", "version": "v2" } ]
2022-12-20
[ [ "Collins", "Jack H.", "" ], [ "Huang", "Yifeng", "" ], [ "Knapen", "Simon", "" ], [ "Nachman", "Benjamin", "" ], [ "Whiteson", "Daniel", "" ] ]
In collider-based particle and nuclear physics experiments, data are produced at such extreme rates that only a subset can be recorded for later analysis. Typically, algorithms select individual collision events for preservation and store the complete experimental response. A relatively new alternative strategy is to additionally save a partial record for a larger subset of events, allowing for later specific analysis of a larger fraction of events. We propose a strategy that bridges these paradigms by compressing entire events for generic offline analysis but at a lower fidelity. An optimal-transport-based $\beta$ Variational Autoencoder (VAE) is used to automate the compression and the hyperparameter $\beta$ controls the compression fidelity. We introduce a new approach for multi-objective learning functions by simultaneously learning a VAE appropriate for all values of $\beta$ through parameterization. We present an example use case, a di-muon resonance search at the Large Hadron Collider (LHC), where we show that simulated data compressed by our $\beta$-VAE has enough fidelity to distinguish distinct signal morphologies.
1306.5352
Ruben Sandapen
Ruben Sandapen and Mohammad Ahmady
Predicting radiative B decays to vector mesons in holographic QCD
5 pages, 3 figures. Proceedings contribution for the XXI International Workshop on Deep-Inelastic Scattering and Related Subjects, 22-26 April 2013, Marseilles, France
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We predict observables in radiative B decays to vector mesons using holographic AdS/QCD Distribution Amplitudes for the vector mesons. We find that end-point divergences can be avoided when computing power-suppressed contributions in the heavy quark limit. The results reported here can be found in references [1] and [2].
[ { "created": "Sat, 22 Jun 2013 19:50:41 GMT", "version": "v1" } ]
2013-06-25
[ [ "Sandapen", "Ruben", "" ], [ "Ahmady", "Mohammad", "" ] ]
We predict observables in radiative B decays to vector mesons using holographic AdS/QCD Distribution Amplitudes for the vector mesons. We find that end-point divergences can be avoided when computing power-suppressed contributions in the heavy quark limit. The results reported here can be found in references [1] and [2].
1005.3370
Oleg Andreev
Oleg Andreev
Renormalized Field Strength Correlators in SU(N) Gauge Theory and Gauge/String Duality
9 pages, 2 figures; v2: new prediction added, discussion improved, to appear in Phys.Lett.B
Phys.Lett.B695:247-251,2011
10.1016/j.physletb.2010.11.029
LMU-ASC 31/10
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use gauge/string duality to analytically evaluate correlation lengths of the renormalized field strength correlators in pure Yang-Mills theories at zero and finite temperature.
[ { "created": "Wed, 19 May 2010 07:23:39 GMT", "version": "v1" }, { "created": "Fri, 12 Nov 2010 09:09:21 GMT", "version": "v2" } ]
2011-02-25
[ [ "Andreev", "Oleg", "" ] ]
We use gauge/string duality to analytically evaluate correlation lengths of the renormalized field strength correlators in pure Yang-Mills theories at zero and finite temperature.
hep-ph/0405027
Egle Tomasi-Gustafsson
Michail P. Rekalo and Egle Tomasi-Gustafsson
$P$-parity of charm and strange particles in electroproduction processes, in collinear regime
4 pages
Phys.Lett. B599 (2004) 247-252
10.1016/j.physletb.2004.08.037
null
hep-ph
null
We show that definite polarization observables for the simplest electroproduction processes, $\ell+N\to \ell+B(1/2^\pm)+M(0^\pm)$, $B=Y(\Lambda, \Sigma$ or $Y_c$-hyperon, $\Theta^+$-pentaquark) and $M=K$, $\bar{K}$ or $D$, are sensitive to the relative P-parity $\pi(B)$ of the NBM-system. The interference of the longitudinal and transversal amplitudes for the collinear regime of the processes $\gamma^*+N\to B+M $($\gamma^*$ is the virtual photon) - at any value of momentum transfer squared and excitation energy of the $BM$-system - generates model independent relations between analyzing powers (in unpolarized lepton scattering by polarized target), from one side, and the components of the produced baryon $B$ polarization. It is important to stress that these relations depend on the above mentioned P-parity, and constitute a model independent method for the determination of unknown parities of strange and charm particles.
[ { "created": "Tue, 4 May 2004 13:19:27 GMT", "version": "v1" } ]
2009-11-10
[ [ "Rekalo", "Michail P.", "" ], [ "Tomasi-Gustafsson", "Egle", "" ] ]
We show that definite polarization observables for the simplest electroproduction processes, $\ell+N\to \ell+B(1/2^\pm)+M(0^\pm)$, $B=Y(\Lambda, \Sigma$ or $Y_c$-hyperon, $\Theta^+$-pentaquark) and $M=K$, $\bar{K}$ or $D$, are sensitive to the relative P-parity $\pi(B)$ of the NBM-system. The interference of the longitudinal and transversal amplitudes for the collinear regime of the processes $\gamma^*+N\to B+M $($\gamma^*$ is the virtual photon) - at any value of momentum transfer squared and excitation energy of the $BM$-system - generates model independent relations between analyzing powers (in unpolarized lepton scattering by polarized target), from one side, and the components of the produced baryon $B$ polarization. It is important to stress that these relations depend on the above mentioned P-parity, and constitute a model independent method for the determination of unknown parities of strange and charm particles.
hep-ph/0010110
Herbert Weigel
H. Weigel
Strongly Distorted Baryon Wave-Functions: Hyperon Beta-Decay and the Spin of the Lambda and the Nucleon
Talk presented at the international conference `Symmetry and Spin' Prague, July 2000. To appear in the Proceedings. 6 pages LaTeX
null
null
MIT-CTP-3017
hep-ph
null
Within the collective coordinate approach to chiral soliton models we suggest that breaking of SU(3) flavor symmetry mainly resides in the baryon wave-functions while the charge operators have no (or only small) symmetry breaking components. In this framework we study the $g_A/g_V$ ratios for hyperon beta-decay as well as the various quark flavor components of the axial charge of the nucleon and the $\Lambda$-hyperon.
[ { "created": "Wed, 11 Oct 2000 11:59:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Weigel", "H.", "" ] ]
Within the collective coordinate approach to chiral soliton models we suggest that breaking of SU(3) flavor symmetry mainly resides in the baryon wave-functions while the charge operators have no (or only small) symmetry breaking components. In this framework we study the $g_A/g_V$ ratios for hyperon beta-decay as well as the various quark flavor components of the axial charge of the nucleon and the $\Lambda$-hyperon.
1809.02539
A. B. Balantekin
A.B. Balantekin
Symmetries and Algebraic Methods in Neutrino Physics
19 pages of latex
null
null
null
hep-ph astro-ph.SR nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symmetry properties associated with neutrino propagation with or without a background of other particles, including neutrinos, is reviewed. The utility of symmetries is illustrated with examples chosen from the see-saw mechanism and both matter-enhanced and collective neutrino oscillations. The role of symmetries in neutrino astrophysics is highlighted.
[ { "created": "Fri, 7 Sep 2018 15:29:38 GMT", "version": "v1" } ]
2018-09-10
[ [ "Balantekin", "A. B.", "" ] ]
Symmetry properties associated with neutrino propagation with or without a background of other particles, including neutrinos, is reviewed. The utility of symmetries is illustrated with examples chosen from the see-saw mechanism and both matter-enhanced and collective neutrino oscillations. The role of symmetries in neutrino astrophysics is highlighted.
0809.3210
Leonard Lesniak
L. Lesniak
New parameterization of the resonant production amplitudes near an inelastic threshold
4 pages, 1 figure, contribution to MESON 2008, Tenth International Workshop on Meson Production, Properties and Interaction, 6-10 June, Krakow, Poland, to be published in International Journal of Modern Physics A
null
10.1142/S0217751X09044048
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New formulae for the resonant scattering and the production amplitudes near an inelastic threshold are derived. It is shown that the Flatte formula, frequently used in experimental analyses, is not sufficiently accurate. Its application to data analysis can lead to a substantial distortion of the effective mass spectra and of the resonance pole positions. A unitary parameterization, satisfying a generalized Watson theorem for the production amplitudes, is proposed. It can be easily applied to study production processes, multichannel meson-meson interactions and the resonance properties, including among others the scalar resonances a0(980) and f_0(980).
[ { "created": "Thu, 18 Sep 2008 17:18:32 GMT", "version": "v1" } ]
2009-11-13
[ [ "Lesniak", "L.", "" ] ]
New formulae for the resonant scattering and the production amplitudes near an inelastic threshold are derived. It is shown that the Flatte formula, frequently used in experimental analyses, is not sufficiently accurate. Its application to data analysis can lead to a substantial distortion of the effective mass spectra and of the resonance pole positions. A unitary parameterization, satisfying a generalized Watson theorem for the production amplitudes, is proposed. It can be easily applied to study production processes, multichannel meson-meson interactions and the resonance properties, including among others the scalar resonances a0(980) and f_0(980).
hep-ph/9603313
Andre Hoang
K.G. Chetyrkin (MPI f\"ur Physik, Munich, Germany), A.H. Hoang, J.H. Kuehn, M. Steinhauser (Uni. Karlsruhe, Germany), T. Teubner (Durham Uni., UK)
Double Bubble Corrections to Heavy Quark Production
9 pages, latex, 17 figures, the complete postscript file of this preprint, including figures, is available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ttp96-04/ttp96-04.ps (129.13.102.139) or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Phys.Lett. B384 (1996) 233-240
10.1016/0370-2693(96)00789-7
TTP96-04, MPI/PhT/96-10, DPT/96/12
hep-ph
null
Second order ${\cal O}(\alpha_s^2)$ corrections to the heavy quark production cross-section due to massless quarks and coloured scalars are calculated for all energies above threshold. Based on the method introduced in this letter also the gauge non-invariant second order corrections due to the pure gluonic selfenergy insertion and a certain class of ${\cal{O}}(\alpha_s^3)$ and ${\cal{O}}(\alpha_s^4)$ corrections are determined. For the special choice of the gauge parameter, $\xi=4$, the leading threshold and high energy behaviour of the pure second order gluonic corrections to the cross-section are governed by the gluonic self energy insertion.
[ { "created": "Thu, 14 Mar 1996 16:09:23 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chetyrkin", "K. G.", "", "MPI für Physik, Munich, Germany" ], [ "Hoang", "A. H.", "", "Uni. Karlsruhe, Germany" ], [ "Kuehn", "J. H.", "", "Uni. Karlsruhe, Germany" ], [ "Steinhauser", "M.", "", "Uni. Karlsruhe, Germany" ], [ "Teubner", "T.", "", "Durham Uni., UK" ] ]
Second order ${\cal O}(\alpha_s^2)$ corrections to the heavy quark production cross-section due to massless quarks and coloured scalars are calculated for all energies above threshold. Based on the method introduced in this letter also the gauge non-invariant second order corrections due to the pure gluonic selfenergy insertion and a certain class of ${\cal{O}}(\alpha_s^3)$ and ${\cal{O}}(\alpha_s^4)$ corrections are determined. For the special choice of the gauge parameter, $\xi=4$, the leading threshold and high energy behaviour of the pure second order gluonic corrections to the cross-section are governed by the gluonic self energy insertion.
2401.04137
Ashok Kapoor
A. K. Kapoor
Parisi-Wu Quantization, CP violation and Beyond the Standard Model
6 pages; accepted for publication in Mod. Phys. Letters A
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
The Parisi-Wu scheme of quantization opens up the possibility of using anomalous fermionic gauge theories. An analysis of ultra-violet divergences reveals that the structure of counter terms is different from what is expected in conventional quantization schemes. In this letter it is argued that there exists a possible mechanism of CP violation that requires at least three generations of quarks, a result well known from a phenomenological analysis of mass mixing of quarks. A few observations on possible ways of going beyond the standard model are included.
[ { "created": "Sun, 7 Jan 2024 11:08:01 GMT", "version": "v1" } ]
2024-01-10
[ [ "Kapoor", "A. K.", "" ] ]
The Parisi-Wu scheme of quantization opens up the possibility of using anomalous fermionic gauge theories. An analysis of ultra-violet divergences reveals that the structure of counter terms is different from what is expected in conventional quantization schemes. In this letter it is argued that there exists a possible mechanism of CP violation that requires at least three generations of quarks, a result well known from a phenomenological analysis of mass mixing of quarks. A few observations on possible ways of going beyond the standard model are included.
hep-ph/9603255
Gabriel Sanchez Colon
A. Garcia (1), R. Huerta (2), G. Sanchez-Colon (2) ((1) CINVESTAV-IPN Mexico, (2) CINVESTAV-IPN Unidad Merida)
A Priori Mixed Baryons and Weak Radiative Decays
Final version
Rev.Mex.Fis. 43 (1996) 232-239
null
SMF1522
hep-ph
null
A priori mixings of eigenstates in physical states are quantum mechanical effects well known in several realms of physics. The possibility that such effects are also present in particle physics, in the form of flavor and parity mixings, is studied. An application to weak radiative decays of hyperons is discussed. It is suggested that this scheme may also be present in non-leptonic and rare mode decays as the enhancement phenomenon.
[ { "created": "Sat, 9 Mar 1996 04:37:05 GMT", "version": "v1" }, { "created": "Thu, 12 Feb 1998 21:57:53 GMT", "version": "v2" } ]
2008-02-03
[ [ "Garcia", "A.", "" ], [ "Huerta", "R.", "" ], [ "Sanchez-Colon", "G.", "" ] ]
A priori mixings of eigenstates in physical states are quantum mechanical effects well known in several realms of physics. The possibility that such effects are also present in particle physics, in the form of flavor and parity mixings, is studied. An application to weak radiative decays of hyperons is discussed. It is suggested that this scheme may also be present in non-leptonic and rare mode decays as the enhancement phenomenon.
1802.08253
Denis Bernard
Denis Bernard
A 5D, polarised, Bethe-Heitler event generator for $\gamma \to e^+e^-$ conversion
Submitted to Nucl. Instrum. Meth. A
Nucl. Instrum. Meth., A 899 (2018) 85
10.1016/j.nima.2018.05.021
null
hep-ph astro-ph.IM physics.data-an physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a new version of the 5D, exact, polarised, Bethe-Heitler event generator of $\gamma$-ray conversions to $e^+e^-$, developed in the context of the HARPO project, that is able to simulate successive events with different photon energies and on different atomic targets without any substantial CPU overhead. The strong correlation between kinematic variables in the divergence of the five-dimensional differential cross section are mitigated by performing each step of the conversion in the appropriate Lorentz frame. We extend the verification range down to 1 keV above threshold and up to 1 EeV. This work could pave the way to the precise simulation of the high-performance $\gamma$-ray telescopes and polarimeters of the post-Fermi-LAT area.
[ { "created": "Thu, 22 Feb 2018 16:04:36 GMT", "version": "v1" }, { "created": "Thu, 3 May 2018 17:35:56 GMT", "version": "v2" } ]
2018-06-05
[ [ "Bernard", "Denis", "" ] ]
We describe a new version of the 5D, exact, polarised, Bethe-Heitler event generator of $\gamma$-ray conversions to $e^+e^-$, developed in the context of the HARPO project, that is able to simulate successive events with different photon energies and on different atomic targets without any substantial CPU overhead. The strong correlation between kinematic variables in the divergence of the five-dimensional differential cross section are mitigated by performing each step of the conversion in the appropriate Lorentz frame. We extend the verification range down to 1 keV above threshold and up to 1 EeV. This work could pave the way to the precise simulation of the high-performance $\gamma$-ray telescopes and polarimeters of the post-Fermi-LAT area.
0901.0426
Gui-Jun Ding
Gui-Jun Ding, Jia-Feng Liu and Mu-Lin Yan
Dynamics of Hadronic Molecule in One-Boson Exchange Approach and Possible Heavy Flavor Molecules
21 pages, 11 figures, 8 tables
Phys.Rev.D79:054005,2009
10.1103/PhysRevD.79.054005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the one pion exchange model at quark level to include the short distance contributions coming from $\eta$, $\sigma$, $\rho$ and $\omega$ exchange. This formalism is applied to discuss the possible molecular states of $D\bar{D}^{*}/\bar{D}D^{*}$, $B\bar{B}^{*}/\bar{B}B^{*}$, $DD^{*}$, $BB^{*}$, the pseudoscalar-vector systems with $C=B=1$ and $C=-B=1$ respectively. The "$\delta$ function" term contribution and the S-D mixing effects have been taken into account. We find the conclusions reached after including the heavier mesons exchange are qualitatively the same as those in the one pion exchange model. The previous suggestion that $1^{++}$ $B\bar{B}^{*}/\bar{B}B^{*}$ molecule should exist, is confirmed in the one boson exchange model, whereas $DD^{*}$ bound state should not exist. The $D\bar{D}^{*}/\bar{D}D^{*}$ system can accomodate a $1^{++}$ molecule close to the threshold, the mixing between the molecule and the conventional charmonium has to be considered to identify this state with X(3872). For the $BB^{*}$ system, the pseudoscalar-vector systems with $C=B=1$ and $C=-B=1$, near threshold molecular states may exist. These bound states should be rather narrow, isospin is violated and the I=0 component is dominant. Experimental search channels for these states are suggested.
[ { "created": "Mon, 5 Jan 2009 07:34:35 GMT", "version": "v1" }, { "created": "Sat, 11 Apr 2009 07:33:23 GMT", "version": "v2" } ]
2009-04-13
[ [ "Ding", "Gui-Jun", "" ], [ "Liu", "Jia-Feng", "" ], [ "Yan", "Mu-Lin", "" ] ]
We extend the one pion exchange model at quark level to include the short distance contributions coming from $\eta$, $\sigma$, $\rho$ and $\omega$ exchange. This formalism is applied to discuss the possible molecular states of $D\bar{D}^{*}/\bar{D}D^{*}$, $B\bar{B}^{*}/\bar{B}B^{*}$, $DD^{*}$, $BB^{*}$, the pseudoscalar-vector systems with $C=B=1$ and $C=-B=1$ respectively. The "$\delta$ function" term contribution and the S-D mixing effects have been taken into account. We find the conclusions reached after including the heavier mesons exchange are qualitatively the same as those in the one pion exchange model. The previous suggestion that $1^{++}$ $B\bar{B}^{*}/\bar{B}B^{*}$ molecule should exist, is confirmed in the one boson exchange model, whereas $DD^{*}$ bound state should not exist. The $D\bar{D}^{*}/\bar{D}D^{*}$ system can accomodate a $1^{++}$ molecule close to the threshold, the mixing between the molecule and the conventional charmonium has to be considered to identify this state with X(3872). For the $BB^{*}$ system, the pseudoscalar-vector systems with $C=B=1$ and $C=-B=1$, near threshold molecular states may exist. These bound states should be rather narrow, isospin is violated and the I=0 component is dominant. Experimental search channels for these states are suggested.
hep-ph/9803401
Steven Abel
S. A. Abel, W. N. Cottingham, I. B. Whittingham
Gluon and gluino penguins and the charmless decays of the b quark
30 Pages plain latex; includes 8 eps figures
Phys.Rev.D58:073006,1998
10.1103/PhysRevD.58.073006
CERN-TH 98/87
hep-ph
null
Gluon mediated exclusive hadronic decays of b quarks are studied within the standard model (SM) and the constrained minimally supersymmetric standard model (MSSM). For all allowed regions of the MSSM parameter space (A, tan beta, m_0, m_{1/2}) the penguin magnetic dipole form factor F^R_2 is dominant over the electric dipole and can be larger than the magnetic dipole form factor of the SM. However, overall the SM electric dipole decay amplitude F^L_1 dominates the decay rate. The MSSM penguin contributions to the free quark decay rate approach the 10% level for those regions of parameter space close to the highest allowed values of tan beta (~55) for which the gluino is light (m_{\tilde{g}} \approx 360 GeV) and lies within the range of the six d-squark masses. In these regions the supersymmetric box amplitudes are negligible. The MSSM phases change very little over the allowed parameter space and can lead to significant interference with the SM amplitudes.
[ { "created": "Fri, 20 Mar 1998 13:17:30 GMT", "version": "v1" } ]
2011-01-25
[ [ "Abel", "S. A.", "" ], [ "Cottingham", "W. N.", "" ], [ "Whittingham", "I. B.", "" ] ]
Gluon mediated exclusive hadronic decays of b quarks are studied within the standard model (SM) and the constrained minimally supersymmetric standard model (MSSM). For all allowed regions of the MSSM parameter space (A, tan beta, m_0, m_{1/2}) the penguin magnetic dipole form factor F^R_2 is dominant over the electric dipole and can be larger than the magnetic dipole form factor of the SM. However, overall the SM electric dipole decay amplitude F^L_1 dominates the decay rate. The MSSM penguin contributions to the free quark decay rate approach the 10% level for those regions of parameter space close to the highest allowed values of tan beta (~55) for which the gluino is light (m_{\tilde{g}} \approx 360 GeV) and lies within the range of the six d-squark masses. In these regions the supersymmetric box amplitudes are negligible. The MSSM phases change very little over the allowed parameter space and can lead to significant interference with the SM amplitudes.
hep-ph/0104302
Fayet
Pierre Fayet
About Superpartners and the Origins of the Supersymmetric Standard Model
15 pages. Contribution to ``The Supersymmetric World'' - The Beginnings of the Theory'', G. Kane and M. Shifman eds. (World Scientific, 2000), p. 120
null
null
LPTENS-00/
hep-ph
null
We recall the obstacles which seemed, long ago, to prevent supersymmetry from possibly being a fundamental symmetry of Nature. Which bosons and fermions could be related? Is spontaneous supersymmetry breaking possible? Where is the spin-1/2 Goldstone fermion of supersymmetry? Can one define conserved baryon and lepton numbers in such theories, although they systematically involve self-conjugate Majorana fermions? etc.. We then recall how an early attempt to relate the photon with a ``neutrino'' led to the definition of R-invariance, but that this ``neutrino'' had to be reinterpreted as a new particle, the photino. This led us to the Supersymmetric Standard Model, involving the SU(3) x SU(2) x U(1) gauge interactions of chiral quark and lepton superfields, and of two doublet Higgs superfields responsible for the electroweak breaking and the generation of quark and lepton masses. The original continuous R-invariance was then abandoned in favor of its discrete version, R-parity -- reexpressed as (-1)^2S (-1)^(3B+L) -- so that the gravitino and gluinos can acquire masses. We also comment about supersymmetry breaking.
[ { "created": "Sun, 29 Apr 2001 21:25:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fayet", "Pierre", "" ] ]
We recall the obstacles which seemed, long ago, to prevent supersymmetry from possibly being a fundamental symmetry of Nature. Which bosons and fermions could be related? Is spontaneous supersymmetry breaking possible? Where is the spin-1/2 Goldstone fermion of supersymmetry? Can one define conserved baryon and lepton numbers in such theories, although they systematically involve self-conjugate Majorana fermions? etc.. We then recall how an early attempt to relate the photon with a ``neutrino'' led to the definition of R-invariance, but that this ``neutrino'' had to be reinterpreted as a new particle, the photino. This led us to the Supersymmetric Standard Model, involving the SU(3) x SU(2) x U(1) gauge interactions of chiral quark and lepton superfields, and of two doublet Higgs superfields responsible for the electroweak breaking and the generation of quark and lepton masses. The original continuous R-invariance was then abandoned in favor of its discrete version, R-parity -- reexpressed as (-1)^2S (-1)^(3B+L) -- so that the gravitino and gluinos can acquire masses. We also comment about supersymmetry breaking.
2109.12041
Paul Caucal
Paul Caucal, Yacine Mehtar-Tani
Anomalous diffusion in QCD matter
10 pages, 3 figures, 3 supplemental materials
null
10.1103/PhysRevD.106.L051501
null
hep-ph cond-mat.stat-mech nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effects of quantum corrections on transverse momentum broadening of a fast parton passing through dense QCD matter. We show that, at leading logarithmic accuracy the broadening distribution tends at late times or equivalently for large system sizes $L$ to a universal distribution that only depends on a single scaling variable $k^2_\perp/Q^2_s$ where the typical transverse momentum scale increases with time as $\ln Q_s^2 \simeq (1+2 \beta ) \ln L - \frac{3}{2}(1+\beta )\,\ln\ln L$ up to non-universal terms, with an anomalous dimension $\beta \sim \sqrt{\alpha_s} $. This property is analogous to geometric scaling of gluon distributions in the saturation regime and traveling waves solutions to reaction-diffusion processes. We note that since $\beta >0$ the process is super-diffusive, which is also reflected at large transverse momentum where the scaling distribution exhibits a heavy tail $k_\perp^{4-2\beta }$ akin to L\'{e}vy random walks.
[ { "created": "Fri, 24 Sep 2021 15:54:14 GMT", "version": "v1" } ]
2022-10-05
[ [ "Caucal", "Paul", "" ], [ "Mehtar-Tani", "Yacine", "" ] ]
We study the effects of quantum corrections on transverse momentum broadening of a fast parton passing through dense QCD matter. We show that, at leading logarithmic accuracy the broadening distribution tends at late times or equivalently for large system sizes $L$ to a universal distribution that only depends on a single scaling variable $k^2_\perp/Q^2_s$ where the typical transverse momentum scale increases with time as $\ln Q_s^2 \simeq (1+2 \beta ) \ln L - \frac{3}{2}(1+\beta )\,\ln\ln L$ up to non-universal terms, with an anomalous dimension $\beta \sim \sqrt{\alpha_s} $. This property is analogous to geometric scaling of gluon distributions in the saturation regime and traveling waves solutions to reaction-diffusion processes. We note that since $\beta >0$ the process is super-diffusive, which is also reflected at large transverse momentum where the scaling distribution exhibits a heavy tail $k_\perp^{4-2\beta }$ akin to L\'{e}vy random walks.
1310.6611
Michal Deak Dr.
Grigorios Chachamis, Michal Deak, German Rodrigo
Heavy quark impact factor in kT-factorization
15 pages, 3 figures
null
10.1007/JHEP12(2013)066
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic accuracy in a form suitable for phenomenological studies such as the calculation of the cross-section for single bottom quark production at the LHC within the kT-factorization scheme.
[ { "created": "Thu, 24 Oct 2013 13:34:50 GMT", "version": "v1" } ]
2015-06-17
[ [ "Chachamis", "Grigorios", "" ], [ "Deak", "Michal", "" ], [ "Rodrigo", "German", "" ] ]
We present the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic accuracy in a form suitable for phenomenological studies such as the calculation of the cross-section for single bottom quark production at the LHC within the kT-factorization scheme.
1404.6493
Gabriel Abelof
Gabriel Abelof, Aude Gehrmann-De Ridder, Philipp Maierh\"ofer, Stefano Pozzorini
NNLO QCD subtraction for top-antitop production in the $q\bar{q}$ channel
54 pages, 10 figures
null
10.1007/JHEP08(2014)035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the computation of the double real and real-virtual contributions to top-antitop pair production in the quark-antiquark channel at leading colour. The $q \bar q \to t \bar{t} g$ amplitudes contributing to the real-virtual part are computed with OpenLoops, and their numerical stability in the soft and collinear regions is found to be sufficiently high to perform a realistic NNLO calculation in double precision. The subtraction terms required at real-real and real-virtual levels are constructed within the antenna subtraction formalism extended to deal with the presence of coloured massive final state particles. We show that those subtraction terms approximate the real-real and real-virtual matrix elements in all their singular limits.
[ { "created": "Fri, 25 Apr 2014 18:13:51 GMT", "version": "v1" }, { "created": "Mon, 4 Aug 2014 19:32:47 GMT", "version": "v2" } ]
2015-06-19
[ [ "Abelof", "Gabriel", "" ], [ "Ridder", "Aude Gehrmann-De", "" ], [ "Maierhöfer", "Philipp", "" ], [ "Pozzorini", "Stefano", "" ] ]
We present the computation of the double real and real-virtual contributions to top-antitop pair production in the quark-antiquark channel at leading colour. The $q \bar q \to t \bar{t} g$ amplitudes contributing to the real-virtual part are computed with OpenLoops, and their numerical stability in the soft and collinear regions is found to be sufficiently high to perform a realistic NNLO calculation in double precision. The subtraction terms required at real-real and real-virtual levels are constructed within the antenna subtraction formalism extended to deal with the presence of coloured massive final state particles. We show that those subtraction terms approximate the real-real and real-virtual matrix elements in all their singular limits.
1609.04605
Hiroaki Abuki
H. Abuki
Chiral spiral induced by a strong magnetic field
6 pages, 6 eps figures. Presented at QCD@Work 2016: International Workshop on QCD - Theory and Experiment, June 27-30, Martina-Franca (Italy)
null
10.1051/epjconf/201612900036
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the modification of the chiral phase structure of QCD due to an external magnetic field. We first demonstrate how the effect of magnetic field can systematically be incorporated into a generalized Ginzburg-Landau framework. We then analyze the phase structure in the vicinity of the chiral critical point. In the chiral limit, the effect is found to be so drastic that it totally washes the tricritical point out of the phase diagram, bringing the continent for the chiral spiral. This is the case no matter how small is the intensity of the magnetic field. On the other hand, the current quark mass protects the chiral critical point from a weak magnetic field. However the critical point will eventually be covered by the chiral spiral phase as the magnetic field grows.
[ { "created": "Thu, 15 Sep 2016 12:42:27 GMT", "version": "v1" } ]
2018-09-19
[ [ "Abuki", "H.", "" ] ]
We study the modification of the chiral phase structure of QCD due to an external magnetic field. We first demonstrate how the effect of magnetic field can systematically be incorporated into a generalized Ginzburg-Landau framework. We then analyze the phase structure in the vicinity of the chiral critical point. In the chiral limit, the effect is found to be so drastic that it totally washes the tricritical point out of the phase diagram, bringing the continent for the chiral spiral. This is the case no matter how small is the intensity of the magnetic field. On the other hand, the current quark mass protects the chiral critical point from a weak magnetic field. However the critical point will eventually be covered by the chiral spiral phase as the magnetic field grows.
2309.07838
Ulrich Ellwanger
Ulrich Ellwanger, Cyril Hugonie
Additional Higgs Bosons near 95 and 650 GeV in the NMSSM
17 pages, 13 figures, added properties of charged Higgs bosons and references, modified constraints from couplings of H_SM
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Hints for an additional Higgs boson with a mass of about 95 GeV originate from LEP and searches in the diphoton channel by CMS and ATLAS. A search for resonant production of SM plus BSM Higgs bosons in the diphoton plus bb channel by CMS showed some excess for a 650 GeV resonance decaying into the SM Higgs plus a 95 GeV Higgs boson. We investigate whether these phenomena can be interpreted simultaneously within the NMSSM subject to the latest constraints on couplings of the SM Higgs boson, on extra Higgs bosons from the LHC, and on dark matter direct detection cross sections. We find that the hints for a 95 GeV Higgs boson in the diphoton channel by CMS and ATLAS and in the diphoton plus bb channel by CMS can be fitted simultaneously within the 2 sigma level.
[ { "created": "Thu, 14 Sep 2023 16:32:00 GMT", "version": "v1" }, { "created": "Fri, 1 Dec 2023 16:53:55 GMT", "version": "v2" } ]
2023-12-04
[ [ "Ellwanger", "Ulrich", "" ], [ "Hugonie", "Cyril", "" ] ]
Hints for an additional Higgs boson with a mass of about 95 GeV originate from LEP and searches in the diphoton channel by CMS and ATLAS. A search for resonant production of SM plus BSM Higgs bosons in the diphoton plus bb channel by CMS showed some excess for a 650 GeV resonance decaying into the SM Higgs plus a 95 GeV Higgs boson. We investigate whether these phenomena can be interpreted simultaneously within the NMSSM subject to the latest constraints on couplings of the SM Higgs boson, on extra Higgs bosons from the LHC, and on dark matter direct detection cross sections. We find that the hints for a 95 GeV Higgs boson in the diphoton channel by CMS and ATLAS and in the diphoton plus bb channel by CMS can be fitted simultaneously within the 2 sigma level.
2304.10753
Werner Porod
Werner Porod
Hunting scalar partners of the Higgs boson at the LHC
Contribution to the Corfu Summer Institute 2022 "School and Workshops on Elementary Particle Physics and Gravity"
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Composite Higgs models with a fermionic ultraviolet completion predict in general additional pseudo Nambu Goldstone bosons beside the Higgs multiplet. In this contribution we discuss their LHC signatures and present first bounds in simplified models which can also be applied to generic models like multi-Higgs models. We then demonstrate how these can be combined taking a concrete model based on the SU(5)/SO(5) coset as an example. We use this to show how a proper combination of different channels can lead to an improved bound compared to a single channel analysis.
[ { "created": "Fri, 21 Apr 2023 05:51:07 GMT", "version": "v1" } ]
2023-04-24
[ [ "Porod", "Werner", "" ] ]
Composite Higgs models with a fermionic ultraviolet completion predict in general additional pseudo Nambu Goldstone bosons beside the Higgs multiplet. In this contribution we discuss their LHC signatures and present first bounds in simplified models which can also be applied to generic models like multi-Higgs models. We then demonstrate how these can be combined taking a concrete model based on the SU(5)/SO(5) coset as an example. We use this to show how a proper combination of different channels can lead to an improved bound compared to a single channel analysis.
1202.0284
John Kearney
John Kearney and Aaron Pierce
Neutrinos from Off-Shell Final States and the Indirect Detection of Dark Matter
22 pages, 5 figures
null
10.1103/PhysRevD.86.043527
MCTP-12-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the annihilation of dark matter to neutrinos in the Sun near the WW and tt kinematic thresholds. We investigate the potential importance of annihilation to WW* in a minimal dark matter model in which a Majorana singlet is mixed with a vector-like electroweak doublet, but many results generalize to other models of weakly-interacting dark matter. We re-evaluate the indirect detection constraints on this model and find that, once all annihilation channels are properly taken into account, the most stringent constraints on spin-dependent scattering for dark matter mass 60 GeV < mX < mt are derived from the results of the Super-Kamiokande experiment. Moreover, we establish the model-independent statement that Majorana dark matter whose thermal relic abundance and neutrino signals are both controlled by annihilation via an s-channel Z boson is excluded for 70 GeV < mX < mW. In some models, annihilation to tt* can affect indirect detection, notably by competing with annihilation to gauge boson final states and thereby weakening neutrino signals. However, in the minimal model, this final state is largely negligible, only allowing dark matter with mass a few GeV below the top quark mass to evade exclusion.
[ { "created": "Wed, 1 Feb 2012 21:00:02 GMT", "version": "v1" } ]
2013-05-30
[ [ "Kearney", "John", "" ], [ "Pierce", "Aaron", "" ] ]
We revisit the annihilation of dark matter to neutrinos in the Sun near the WW and tt kinematic thresholds. We investigate the potential importance of annihilation to WW* in a minimal dark matter model in which a Majorana singlet is mixed with a vector-like electroweak doublet, but many results generalize to other models of weakly-interacting dark matter. We re-evaluate the indirect detection constraints on this model and find that, once all annihilation channels are properly taken into account, the most stringent constraints on spin-dependent scattering for dark matter mass 60 GeV < mX < mt are derived from the results of the Super-Kamiokande experiment. Moreover, we establish the model-independent statement that Majorana dark matter whose thermal relic abundance and neutrino signals are both controlled by annihilation via an s-channel Z boson is excluded for 70 GeV < mX < mW. In some models, annihilation to tt* can affect indirect detection, notably by competing with annihilation to gauge boson final states and thereby weakening neutrino signals. However, in the minimal model, this final state is largely negligible, only allowing dark matter with mass a few GeV below the top quark mass to evade exclusion.
2309.05474
Peter Athron
Peter Athron, Lachlan Morris, Zhongxiu Xu
How robust are gravitational wave predictions from cosmological phase transitions?
14 pages, 5 figures, 3 tables; matches version published in JCAP
JCAP 05 (2024) 075
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Gravitational wave (GW) predictions of cosmological phase transitions are almost invariably evaluated at either the nucleation or percolation temperature. We investigate the effect of the transition temperature choice on GW predictions, for phase transitions with weak, intermediate and strong supercooling. We find that the peak amplitude of the GW signal varies by a factor of a few for weakly supercooled phase transitions, and by an order of magnitude for strongly supercooled phase transitions. The variation in amplitude for even weakly supercooled phase transitions can be several orders of magnitude if one uses the mean bubble separation, while the variation is milder if one uses the mean bubble radius instead. We also investigate the impact of various approximations used in GW predictions. Many of these approximations introduce at least a 10% error in the GW signal, with others introducing an error of over an order of magnitude.
[ { "created": "Mon, 11 Sep 2023 14:15:08 GMT", "version": "v1" }, { "created": "Tue, 21 May 2024 08:46:57 GMT", "version": "v2" } ]
2024-05-22
[ [ "Athron", "Peter", "" ], [ "Morris", "Lachlan", "" ], [ "Xu", "Zhongxiu", "" ] ]
Gravitational wave (GW) predictions of cosmological phase transitions are almost invariably evaluated at either the nucleation or percolation temperature. We investigate the effect of the transition temperature choice on GW predictions, for phase transitions with weak, intermediate and strong supercooling. We find that the peak amplitude of the GW signal varies by a factor of a few for weakly supercooled phase transitions, and by an order of magnitude for strongly supercooled phase transitions. The variation in amplitude for even weakly supercooled phase transitions can be several orders of magnitude if one uses the mean bubble separation, while the variation is milder if one uses the mean bubble radius instead. We also investigate the impact of various approximations used in GW predictions. Many of these approximations introduce at least a 10% error in the GW signal, with others introducing an error of over an order of magnitude.
0806.2817
Vladimir Sauli
V. Sauli, Z. Batiz
Quark Schwinger-Dyson equation in temporal Euclidean space
11 pages, grammar and typos corrected
J.Phys.G36:035002,2009
10.1088/0954-3899/36/3/035002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an elementary nonperturbative method to obtain Green's functions (GFs) for timelike momenta. We assume there are no singularities in the first and third quadrants of the complex plane of space momentum components and perform a 3d analogue of Wick rotation. This procedure defines Greens functions in a timelike Euclidean space. As an example we consider the quark propagator in QCD. While for weak coupling, this method is obviously equivalent to perturbation theory, for a realistic QCD coupling a complex part of the quark mass and renormalization wave function has been spontaneously generated even below the standard perturbative threshold. Therefore, our method favors a confinement mechanism based on the lack of real poles.
[ { "created": "Tue, 17 Jun 2008 15:14:25 GMT", "version": "v1" }, { "created": "Mon, 15 Dec 2008 15:53:23 GMT", "version": "v2" } ]
2009-02-02
[ [ "Sauli", "V.", "" ], [ "Batiz", "Z.", "" ] ]
We present an elementary nonperturbative method to obtain Green's functions (GFs) for timelike momenta. We assume there are no singularities in the first and third quadrants of the complex plane of space momentum components and perform a 3d analogue of Wick rotation. This procedure defines Greens functions in a timelike Euclidean space. As an example we consider the quark propagator in QCD. While for weak coupling, this method is obviously equivalent to perturbation theory, for a realistic QCD coupling a complex part of the quark mass and renormalization wave function has been spontaneously generated even below the standard perturbative threshold. Therefore, our method favors a confinement mechanism based on the lack of real poles.
hep-ph/0007176
Wilfried Buchmuller
W. Buchm\"uller and M. Pl\"umacher
Neutrino masses and the baryon asymmetry
45 pages, 12 figures
Int.J.Mod.Phys.A15:5047-5086,2000
10.1016/S0217-751X(00)00293-5
DESY 99-187, UPR-892-T
hep-ph
null
Due to sphaleron processes in the high-temperature symmetric phase of the standard model the cosmological baryon asymmetry is related to neutrino properties. For hierarchical neutrino masses, with $B-L$ broken at the unification scale $\Lambda_{GUT}\sim 10^{16} $GeV, the observed baryon asymmetry $n_B/s \sim 10^{-10}$ can be naturally explained by the decay of heavy Majorana neutrinos. We illustrate this mechanism with two models of neutrino masses, consistent with the solar and atmospheric neutrino anomalies, which are based on the two symmetry groups $SU(5)\times U(1)_F$ and $SU(3)_c\times SU(3)_L\times SU(3)_R\times U(1)_F$. We also review related cosmological bounds on Majorana neutrino masses and the use of Boltzmann equations.
[ { "created": "Mon, 17 Jul 2000 19:50:43 GMT", "version": "v1" } ]
2008-11-26
[ [ "Buchmüller", "W.", "" ], [ "Plümacher", "M.", "" ] ]
Due to sphaleron processes in the high-temperature symmetric phase of the standard model the cosmological baryon asymmetry is related to neutrino properties. For hierarchical neutrino masses, with $B-L$ broken at the unification scale $\Lambda_{GUT}\sim 10^{16} $GeV, the observed baryon asymmetry $n_B/s \sim 10^{-10}$ can be naturally explained by the decay of heavy Majorana neutrinos. We illustrate this mechanism with two models of neutrino masses, consistent with the solar and atmospheric neutrino anomalies, which are based on the two symmetry groups $SU(5)\times U(1)_F$ and $SU(3)_c\times SU(3)_L\times SU(3)_R\times U(1)_F$. We also review related cosmological bounds on Majorana neutrino masses and the use of Boltzmann equations.
1708.00010
Chanda Prescod-Weinstein
Ann Nelson and Chanda Prescod-Weinstein
Relaxion: A Landscape Without Anthropics
updated with new section; similar to version to be published in Physical Review D
Phys. Rev. D 96, 113007 (2017)
10.1103/PhysRevD.96.113007
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The relaxion mechanism provides a potentially elegant solution to the hierarchy problem without resorting to anthropic or other fine-tuning arguments. This mechanism introduces an axion-like field, dubbed the relaxion, whose expectation value determines the electroweak hierarchy as well as the QCD strong CP violating $\bar{\theta}$ parameter. During an inflationary period, the Higgs mass squared is selected to be negative and hierarchically small in a theory which is consistent with 't Hooft's technical naturalness criteria. However, in the original model proposed by Graham, Kaplan and Rajendran (2015), the relaxion does not solve the strong CP problem, and in fact contributes to it, as the coupling of the relaxion to the Higgs field and the introduction of a linear potential for the relaxion produces large strong CP violation. We resolve this tension by considering inflation with a Hubble scale which is above the QCD scale but below the weak scale, and estimating the Hubble temperature dependence of the axion mass. The relaxion potential is thus very different during inflation than it is today. We find that provided the inflationary Hubble scale is between the weak scale and about 3 GeV, the relaxion resolves the hierarchy, strong CP, and dark matter problems in a way that is technically natural.
[ { "created": "Mon, 31 Jul 2017 18:00:07 GMT", "version": "v1" }, { "created": "Fri, 15 Dec 2017 16:18:53 GMT", "version": "v2" } ]
2017-12-27
[ [ "Nelson", "Ann", "" ], [ "Prescod-Weinstein", "Chanda", "" ] ]
The relaxion mechanism provides a potentially elegant solution to the hierarchy problem without resorting to anthropic or other fine-tuning arguments. This mechanism introduces an axion-like field, dubbed the relaxion, whose expectation value determines the electroweak hierarchy as well as the QCD strong CP violating $\bar{\theta}$ parameter. During an inflationary period, the Higgs mass squared is selected to be negative and hierarchically small in a theory which is consistent with 't Hooft's technical naturalness criteria. However, in the original model proposed by Graham, Kaplan and Rajendran (2015), the relaxion does not solve the strong CP problem, and in fact contributes to it, as the coupling of the relaxion to the Higgs field and the introduction of a linear potential for the relaxion produces large strong CP violation. We resolve this tension by considering inflation with a Hubble scale which is above the QCD scale but below the weak scale, and estimating the Hubble temperature dependence of the axion mass. The relaxion potential is thus very different during inflation than it is today. We find that provided the inflationary Hubble scale is between the weak scale and about 3 GeV, the relaxion resolves the hierarchy, strong CP, and dark matter problems in a way that is technically natural.
2004.01111
Marta Luszczak Mrs
Marta {\L}uszczak and Antoni Szczurek
Production of heavy particle pairs via photon-photon processes at the LHC
11 pages, 9 figures, a talk presented by Marta {\L}uszczak at XXVI Cracow EPIPHANY Conference, LHC Physics: Standard Model and Beyond, 7-10 January 2020
null
10.5506/APhysPolB.51.1449
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss production of $W^+ W^-$ pairs and $t \bar t$ quark-antiquark pairs in proton-proton collisions induced by two-photon fusion including transverse momenta of incoming photons. The unintegrated inelastic fluxes (related to proton dissociation) of photons are calculated based on modern parametrizations of deep inelastic structure functions in a broad range of $x$ and $Q^2$. We focus on processes with single and double proton dissociation. Highly excited remnant systems hadronise producing particles that can be vetoed in the calorimeter. We calculate associated gap survival factors. The gap survival factors depend on the process, mass of the remnant system and collision energy. The rapidity gap survival factor due to remnant fragmentation for double dissociative (DD) collisions is smaller than that for single dissociative (SD) process. We observe approximate factorisation: $S_{R,DD} \approx S_{R,SD}^2$ when imposing rapidity veto. For the $W^+W^-$ final state, the remnant fragmentation leads to a taming of the cross section when the rapidity gap requirement is imposed. Also for $t \bar t$ quark-antiquark pairs such a condition reverses the hierarchy observed for the case when such condition is taken into account. Our results imply that for the production of such heavy objects as $t$ quark and $\bar t$ antiquark the virtuality of the photons attached to the dissociative system are very large ($Q^2 <$ 10$^{4}$ GeV$^2$). A similar effect is observed for the $W^+ W^-$ system.
[ { "created": "Thu, 2 Apr 2020 16:22:03 GMT", "version": "v1" } ]
2020-08-26
[ [ "Łuszczak", "Marta", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss production of $W^+ W^-$ pairs and $t \bar t$ quark-antiquark pairs in proton-proton collisions induced by two-photon fusion including transverse momenta of incoming photons. The unintegrated inelastic fluxes (related to proton dissociation) of photons are calculated based on modern parametrizations of deep inelastic structure functions in a broad range of $x$ and $Q^2$. We focus on processes with single and double proton dissociation. Highly excited remnant systems hadronise producing particles that can be vetoed in the calorimeter. We calculate associated gap survival factors. The gap survival factors depend on the process, mass of the remnant system and collision energy. The rapidity gap survival factor due to remnant fragmentation for double dissociative (DD) collisions is smaller than that for single dissociative (SD) process. We observe approximate factorisation: $S_{R,DD} \approx S_{R,SD}^2$ when imposing rapidity veto. For the $W^+W^-$ final state, the remnant fragmentation leads to a taming of the cross section when the rapidity gap requirement is imposed. Also for $t \bar t$ quark-antiquark pairs such a condition reverses the hierarchy observed for the case when such condition is taken into account. Our results imply that for the production of such heavy objects as $t$ quark and $\bar t$ antiquark the virtuality of the photons attached to the dissociative system are very large ($Q^2 <$ 10$^{4}$ GeV$^2$). A similar effect is observed for the $W^+ W^-$ system.
2107.12934
Najimuddin Khan
Shreyashi Chakdar, Dilip Kumar Ghosh, P. Q. Hung, Najimuddin Khan, Dibyendu Nanda
A model of light pseudoscalar dark matter
48 pages and 12 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The EW-$\nu_R$ model was constructed in order to provide a seesaw scenario operating at the Electroweak scale $\Lambda_{EW} \sim 246$ GeV, keeping the same SM gauge structure. In this model, right-handed neutrinos are non-sterile and have masses of the order of $\Lambda_{EW}$. They can be searched for at the LHC along with heavy mirror quarks and leptons, the lightest of which have large decay lengths. The seesaw mechanism requires the existence of a complex scalar which is singlet under the SM gauge group. The imaginary part of this complex scalar denoted by $A^{0}_s$ is proposed to be the sub-MeV dark matter candidate in this manuscript. We find that the sub-MeV scalar can serve as a viable non-thermal feebly interacting massive particle (FIMP)-DM candidate. This $A_s^0$ can be a naturally light sub-MeV DM candidate due to its nature as a pseudo-Nambu-Goldstone (PNG) boson in the model. We show that the well-studied freeze out mechanism falls short in this particular framework producing DM overabundance. We identify that the freeze in mechanism produce the correct order of relic density for the sub-MeV DM candidate satisfying all applicable constraints. We then discuss the DM parameter space allowed by the current bounds from the direct and indirect searches for this sub-MeV DM. This model has a very rich scalar sector, consistent with various experimental constraints, predicts a $\sim 125$ GeV scalar with the SM Higgs characteristics satisfying the current LHC Higgs boson data.
[ { "created": "Tue, 27 Jul 2021 16:43:22 GMT", "version": "v1" } ]
2021-07-28
[ [ "Chakdar", "Shreyashi", "" ], [ "Ghosh", "Dilip Kumar", "" ], [ "Hung", "P. Q.", "" ], [ "Khan", "Najimuddin", "" ], [ "Nanda", "Dibyendu", "" ] ]
The EW-$\nu_R$ model was constructed in order to provide a seesaw scenario operating at the Electroweak scale $\Lambda_{EW} \sim 246$ GeV, keeping the same SM gauge structure. In this model, right-handed neutrinos are non-sterile and have masses of the order of $\Lambda_{EW}$. They can be searched for at the LHC along with heavy mirror quarks and leptons, the lightest of which have large decay lengths. The seesaw mechanism requires the existence of a complex scalar which is singlet under the SM gauge group. The imaginary part of this complex scalar denoted by $A^{0}_s$ is proposed to be the sub-MeV dark matter candidate in this manuscript. We find that the sub-MeV scalar can serve as a viable non-thermal feebly interacting massive particle (FIMP)-DM candidate. This $A_s^0$ can be a naturally light sub-MeV DM candidate due to its nature as a pseudo-Nambu-Goldstone (PNG) boson in the model. We show that the well-studied freeze out mechanism falls short in this particular framework producing DM overabundance. We identify that the freeze in mechanism produce the correct order of relic density for the sub-MeV DM candidate satisfying all applicable constraints. We then discuss the DM parameter space allowed by the current bounds from the direct and indirect searches for this sub-MeV DM. This model has a very rich scalar sector, consistent with various experimental constraints, predicts a $\sim 125$ GeV scalar with the SM Higgs characteristics satisfying the current LHC Higgs boson data.
2202.01504
Kazem Azizi
N. Er, K. Azizi
Spectroscopic parameters and electromagnetic form factor of kaon in vacuum and a dense medium
10 Pages, 13 Figures and 3 Tables
null
10.1140/epjc/s10052-022-10333-w
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
The spectroscopic parameters as well as electromagnetic form factor of the strange particle kaon are investigated in vacuum and a medium with finite density. The obtained vacuum mass and decay constant, which are consistent with the existing experimental results, are used to extract the $ Q^2 $ dependence of the kaon electromagnetic form factor in the interval $Q^2\in [0,10]$ GeV$^2$ in vacuum. The obtained results at lower and intermediate values of $ Q^2 $ are consistent with the existing experimental data within the presented uncertainties. The $ Q^2 $ behavior of the electromagnetic form factor of kaon in vacuum and in the interval $Q^2\in [0,6]$ GeV$^2$ is in a nice agreement with the existing predictions of the Lattice QCD and the solution of the Bethe-Salpeter equation for the model of Nambu and Jona-Lasinio (NJL) with proper-time regularization, as well. The obtained vacuum radius for kaon is also in a nice agreement with the world's average experimental result. We extend the analyses to a medium with higher densities and obtain the behavior of the mass, decay constant, electromagnetic form factor and radius with respect to density. The obtained results for some of the parameters are compared with the existing predictions of other models and approaches. The results obtained in the present study can be useful for future experimental and theoretical studies both in vacuum and a dense medium.
[ { "created": "Thu, 3 Feb 2022 10:27:05 GMT", "version": "v1" }, { "created": "Tue, 26 Apr 2022 19:28:43 GMT", "version": "v2" } ]
2022-05-18
[ [ "Er", "N.", "" ], [ "Azizi", "K.", "" ] ]
The spectroscopic parameters as well as electromagnetic form factor of the strange particle kaon are investigated in vacuum and a medium with finite density. The obtained vacuum mass and decay constant, which are consistent with the existing experimental results, are used to extract the $ Q^2 $ dependence of the kaon electromagnetic form factor in the interval $Q^2\in [0,10]$ GeV$^2$ in vacuum. The obtained results at lower and intermediate values of $ Q^2 $ are consistent with the existing experimental data within the presented uncertainties. The $ Q^2 $ behavior of the electromagnetic form factor of kaon in vacuum and in the interval $Q^2\in [0,6]$ GeV$^2$ is in a nice agreement with the existing predictions of the Lattice QCD and the solution of the Bethe-Salpeter equation for the model of Nambu and Jona-Lasinio (NJL) with proper-time regularization, as well. The obtained vacuum radius for kaon is also in a nice agreement with the world's average experimental result. We extend the analyses to a medium with higher densities and obtain the behavior of the mass, decay constant, electromagnetic form factor and radius with respect to density. The obtained results for some of the parameters are compared with the existing predictions of other models and approaches. The results obtained in the present study can be useful for future experimental and theoretical studies both in vacuum and a dense medium.
hep-ph/9607373
Claudio Parrinello
D.S. Henty, C. Parrinello, D.G. Richards, J.I. Skullerud
Soft Pomeron Physics on the Lattice
8 pages, Latex, 2 PostScript figures and 2 style files included, to appear in the Proceedings of DIS96
null
null
Univ. of Liverpool LTH-378, Univ of Edinburgh 96/15
hep-ph
null
We discuss strategies for using lattice QCD to investigate some topics in strong interaction phenomenology which are usually related to soft pomeron exchange. These include hadronic cross-sections at high energies and diffractive scattering at HERA. Some numerical results are presented in the framework of the Landshoff-Nachtmann pomeron model.
[ { "created": "Fri, 19 Jul 1996 10:30:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Henty", "D. S.", "" ], [ "Parrinello", "C.", "" ], [ "Richards", "D. G.", "" ], [ "Skullerud", "J. I.", "" ] ]
We discuss strategies for using lattice QCD to investigate some topics in strong interaction phenomenology which are usually related to soft pomeron exchange. These include hadronic cross-sections at high energies and diffractive scattering at HERA. Some numerical results are presented in the framework of the Landshoff-Nachtmann pomeron model.
1401.6397
Ketan Patel
Anjan S. Joshipura, Ketan M. Patel
A massless neutrino and lepton mixing patterns from finite discrete subgroups of U(3)
22 pages, minor changes, version accepted for publication in JHEP
JHEP 1404 (2014) 009
10.1007/JHEP04(2014)009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finite discrete subgroups of $U(3)$ as possible flavour symmetries $G_f$ for a massless neutrinos with predictive mixing angles are studied. This is done by assuming that a residual symmetry $S_\nu$ appropriate for describing a massless neutrino is contained in $G_f$. It is shown that all the groups $G_f$ admitting three dimensional faithful irreducible representation and generated from a specific set of $3\times 3$ matrices imply only one of the three flavour compositions for the massless state namely, unmixed, maximally mixed with equal probabilities and bimaximally mixed with probabilities (0,1/2,1/2) and their permutations. This result holds irrespective of the order of $G_f$ and the choice of $S_{\nu}$ within it. All of these lead to unfavourable leading order prediction for the solar mixing angle. Neutrino mixing pattern is then numerically investigated in case of subgroups of $U(3)$ with order less than 512 and it is found that only one of these can lead to a massless neutrino and leading order predictions for all the mixing angles close to their experimental values. Ways to correct for the solar angle prediction are proposed and two concrete examples giving the observed mixing pattern are discussed.
[ { "created": "Fri, 24 Jan 2014 16:46:27 GMT", "version": "v1" }, { "created": "Thu, 20 Mar 2014 07:10:21 GMT", "version": "v2" } ]
2014-04-07
[ [ "Joshipura", "Anjan S.", "" ], [ "Patel", "Ketan M.", "" ] ]
Finite discrete subgroups of $U(3)$ as possible flavour symmetries $G_f$ for a massless neutrinos with predictive mixing angles are studied. This is done by assuming that a residual symmetry $S_\nu$ appropriate for describing a massless neutrino is contained in $G_f$. It is shown that all the groups $G_f$ admitting three dimensional faithful irreducible representation and generated from a specific set of $3\times 3$ matrices imply only one of the three flavour compositions for the massless state namely, unmixed, maximally mixed with equal probabilities and bimaximally mixed with probabilities (0,1/2,1/2) and their permutations. This result holds irrespective of the order of $G_f$ and the choice of $S_{\nu}$ within it. All of these lead to unfavourable leading order prediction for the solar mixing angle. Neutrino mixing pattern is then numerically investigated in case of subgroups of $U(3)$ with order less than 512 and it is found that only one of these can lead to a massless neutrino and leading order predictions for all the mixing angles close to their experimental values. Ways to correct for the solar angle prediction are proposed and two concrete examples giving the observed mixing pattern are discussed.
1805.06726
Sergey Afonin
S. S. Afonin and T. D. Solomko
The large-Nc masses of light scalar mesons from QCD sum rules for linear radial spectrum
6 pages, 2 figures, presented at Excited QCD 2018
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a calculation of large-Nc masses of light scalar mesons from the QCD sum rules. Two methods based on the use of linear radial Regge trajectories are presented. We put a special emphasis on the appearance of pole near 0.5 GeV in the scalar isoscalar channel which emerges in both methods and presumably corresponds to the scalar sigma-meson.
[ { "created": "Thu, 17 May 2018 12:36:13 GMT", "version": "v1" }, { "created": "Tue, 29 May 2018 12:30:31 GMT", "version": "v2" } ]
2018-05-30
[ [ "Afonin", "S. S.", "" ], [ "Solomko", "T. D.", "" ] ]
We discuss a calculation of large-Nc masses of light scalar mesons from the QCD sum rules. Two methods based on the use of linear radial Regge trajectories are presented. We put a special emphasis on the appearance of pole near 0.5 GeV in the scalar isoscalar channel which emerges in both methods and presumably corresponds to the scalar sigma-meson.
hep-ph/0408047
Andre Sopczak
Andre Sopczak (Lancaster University)
Searches for Higgs Bosons Beyond the Standard Model
6 pages, 10 figures. Contribution to the XII Workshop on Deep Inelastic Scattering, DIS'2004, High Tatras, Slovakia, 14-18 April 2004
null
null
null
hep-ph
null
Latest results from the combined data of the four LEP experiments ALEPH, DELPHI, L3 and OPAL on Higgs boson searches in extensions of the Standard Model (SM) are presented.
[ { "created": "Tue, 3 Aug 2004 19:33:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sopczak", "Andre", "", "Lancaster University" ] ]
Latest results from the combined data of the four LEP experiments ALEPH, DELPHI, L3 and OPAL on Higgs boson searches in extensions of the Standard Model (SM) are presented.
2208.13719
Ingo Schienbein
Lohan Sartore, Markos Maniatis, Ingo Schienbein, Bjoern Herrmann
The general Two-Higgs Doublet Model in a gauge-invariant form
40 pages
null
10.1007/JHEP12(2022)051
LAPTH-045/22
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
In the general Two-Higgs Doublet Model it has been shown that the Higgs potential can be expressed in terms of gauge-independent quantities. In particular, stability, electroweak symmetry breaking, and CP symmetry can be understood in a concise way, avoiding unphysical gauge degrees of freedom. We complete this program and show how all the masses, the trilinear and quartic scalar interactions, the gauge-boson-Higgs interactions, as well as the Yukawa couplings in the general THDM can be expressed in a gauge-invariant way.
[ { "created": "Mon, 29 Aug 2022 16:59:33 GMT", "version": "v1" } ]
2022-12-28
[ [ "Sartore", "Lohan", "" ], [ "Maniatis", "Markos", "" ], [ "Schienbein", "Ingo", "" ], [ "Herrmann", "Bjoern", "" ] ]
In the general Two-Higgs Doublet Model it has been shown that the Higgs potential can be expressed in terms of gauge-independent quantities. In particular, stability, electroweak symmetry breaking, and CP symmetry can be understood in a concise way, avoiding unphysical gauge degrees of freedom. We complete this program and show how all the masses, the trilinear and quartic scalar interactions, the gauge-boson-Higgs interactions, as well as the Yukawa couplings in the general THDM can be expressed in a gauge-invariant way.
2405.02254
Javad Shahrzad
Javad Shahrzad, Ali Khorramian
QCD analysis of valence structure functions using deep inelastic lepton-nucleon scattering
26 pages, 15 figures, 4 tables
Phys. Rev. D 109, 114002 (2024)
10.1103/PhysRevD.109.114002
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
A new ''$\mathtt{SK24}$'' non-singlet QCD analysis of the structure functions at the NNLO approximation is performed, utilizing the global fit of the data from various charged lepton scattering experiments. We extract the valence parton distribution functions (PDFs) and provide a parametrization of them, along with the correlated errors for a wide range of $x$ and $Q^2$. We compare valence PDFs and their uncertainties with those from different PDF sets provided by various groups. We also obtain valence PDFs and the strong coupling constant $\alpha_{s}(M_Z^2)$, taking into account the nuclear correction concerning large $x$ as well as the target mass correction (TMC) and higher twist (HT) effects at the NNLO. In the large $x$ region, we extract the higher twist contributions of $xF_3(x,Q^2)$, $F_2^p (x,Q^2)$, and $F_2^d(x,Q^2)$. We determine $\alpha_{s}(M_Z^2)$ without and with considering the TMC and HT corrections and perform a comparison with the world average of $\alpha_{s}(M_Z^2)$ and other reported results. The extracted results concerning valence PDFs with their uncertainties and $\alpha_{s}(M_Z^2)$ value agree with available theoretical models.
[ { "created": "Fri, 3 May 2024 17:12:59 GMT", "version": "v1" } ]
2024-06-07
[ [ "Shahrzad", "Javad", "" ], [ "Khorramian", "Ali", "" ] ]
A new ''$\mathtt{SK24}$'' non-singlet QCD analysis of the structure functions at the NNLO approximation is performed, utilizing the global fit of the data from various charged lepton scattering experiments. We extract the valence parton distribution functions (PDFs) and provide a parametrization of them, along with the correlated errors for a wide range of $x$ and $Q^2$. We compare valence PDFs and their uncertainties with those from different PDF sets provided by various groups. We also obtain valence PDFs and the strong coupling constant $\alpha_{s}(M_Z^2)$, taking into account the nuclear correction concerning large $x$ as well as the target mass correction (TMC) and higher twist (HT) effects at the NNLO. In the large $x$ region, we extract the higher twist contributions of $xF_3(x,Q^2)$, $F_2^p (x,Q^2)$, and $F_2^d(x,Q^2)$. We determine $\alpha_{s}(M_Z^2)$ without and with considering the TMC and HT corrections and perform a comparison with the world average of $\alpha_{s}(M_Z^2)$ and other reported results. The extracted results concerning valence PDFs with their uncertainties and $\alpha_{s}(M_Z^2)$ value agree with available theoretical models.
1004.1880
Song He
Song He, Mei Huang, Qi-Shu Yan
Logarithmic correction in the deformed ${\rm AdS}_5$ model to produce the heavy quark potential and QCD beta function
24 pages, 16 figures
Phys.Rev.D83:045034,2011
10.1103/PhysRevD.83.045034
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We stude the \textit{holographic} QCD model which contains a quadratic term $ -\sigma z^2$ and a logarithmic term $-c_0\log[(z_{IR}-z)/z_{IR}]$ with an explicit infrared cut-off $z_{IR}$ in the deformed ${\rm AdS}_5$ warp factor. We investigate the heavy quark potential for three cases, i.e, with only quadratic correction, with both quadratic and logarithmic corrections and with only logarithmic correction. We solve the dilaton field and dilation potential from the Einstein equation, and investigate the corresponding beta function in the G{\"u}rsoy -Kiritsis-Nitti (GKN) framework. Our studies show that in the case with only quadratic correction, a negative $\sigma$ or the Andreev-Zakharov model is favored to fit the heavy quark potential and to produce the QCD beta-function at 2-loop level, however, the dilaton potential is unbounded in infrared regime. One interesting observing for the case of positive $\sigma$, or the soft-wall ${\rm AdS}_5$ model is that the corresponding beta-function exists an infrared fixed point. In the case with only logarithmic correction, the heavy quark Cornell potential can be fitted very well, the corresponding beta-function agrees with the QCD beta-function at 2-loop level reasonably well, and the dilaton potential is bounded from below in infrared. At the end, we propose a more compact model which has only logarithmic correction in the deformed warp factor and has less free parameters.
[ { "created": "Mon, 12 Apr 2010 07:08:27 GMT", "version": "v1" } ]
2011-03-23
[ [ "He", "Song", "" ], [ "Huang", "Mei", "" ], [ "Yan", "Qi-Shu", "" ] ]
We stude the \textit{holographic} QCD model which contains a quadratic term $ -\sigma z^2$ and a logarithmic term $-c_0\log[(z_{IR}-z)/z_{IR}]$ with an explicit infrared cut-off $z_{IR}$ in the deformed ${\rm AdS}_5$ warp factor. We investigate the heavy quark potential for three cases, i.e, with only quadratic correction, with both quadratic and logarithmic corrections and with only logarithmic correction. We solve the dilaton field and dilation potential from the Einstein equation, and investigate the corresponding beta function in the G{\"u}rsoy -Kiritsis-Nitti (GKN) framework. Our studies show that in the case with only quadratic correction, a negative $\sigma$ or the Andreev-Zakharov model is favored to fit the heavy quark potential and to produce the QCD beta-function at 2-loop level, however, the dilaton potential is unbounded in infrared regime. One interesting observing for the case of positive $\sigma$, or the soft-wall ${\rm AdS}_5$ model is that the corresponding beta-function exists an infrared fixed point. In the case with only logarithmic correction, the heavy quark Cornell potential can be fitted very well, the corresponding beta-function agrees with the QCD beta-function at 2-loop level reasonably well, and the dilaton potential is bounded from below in infrared. At the end, we propose a more compact model which has only logarithmic correction in the deformed warp factor and has less free parameters.
hep-ph/9807363
Photis Moulatsiotis
Mark Hindmarsh and Photis Moulatsiotis (Sussex)
Constraints on Axion Models from $K^+\to\pi^+ a$
15pp RevTeX, 1 eps fig, uses graphics style. Expanded discussion on massive scalars and pseudoscalars, typos. To appear in Physical Review D
Phys. Rev. D 59, 055015 (1999)
10.1103/PhysRevD.59.055015
SUSX-TH-98-017
hep-ph
null
We explore a new class of axion models in which some, but not all, of the left-handed quarks have a Peccei-Quinn symmetry. These models are potentially afflicted by flavour changing neutral currents. We derive the bounds on the Peccei-Quinn symmetry-breaking scale from bounds on the $K^+\to \pi^+ a$ branching ratio, showing that in some cases they are even stronger than the astrophysical ones, but still not strong enough to kill off the models.
[ { "created": "Mon, 13 Jul 1998 18:48:12 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 1998 11:13:51 GMT", "version": "v2" } ]
2016-08-25
[ [ "Hindmarsh", "Mark", "", "Sussex" ], [ "Moulatsiotis", "Photis", "", "Sussex" ] ]
We explore a new class of axion models in which some, but not all, of the left-handed quarks have a Peccei-Quinn symmetry. These models are potentially afflicted by flavour changing neutral currents. We derive the bounds on the Peccei-Quinn symmetry-breaking scale from bounds on the $K^+\to \pi^+ a$ branching ratio, showing that in some cases they are even stronger than the astrophysical ones, but still not strong enough to kill off the models.
hep-ph/0312354
Leonid Glozman
L. Ya. Glozman
Chiral multiplets of excited mesons
14 pages, discussion and conclusion section is largely extended
Phys.Lett.B587:69-77,2004
10.1016/j.physletb.2004.02.066
null
hep-ph hep-ex hep-lat nucl-th
null
It is shown that experimental meson states with spins J=0,1,2,3 in the energy range 1.9 - 2.4 GeV obtained in recent partial wave analysis of proton-antiproton annihilation at LEAR remarkably confirm all predictions of chiral symmetry restoration. Classification of excited $\bar q q$ mesons according to the representations of chiral $U(2)_L \times U(2)_R$ group is performed. There are two important predictions of chiral symmetry restoration in highly excited mesons: (i) physical states must fill out approximately degenerate parity-chiral multiplets; (ii) some of the physical states with the given $I,J^{PC}$ are members of one parity-chiral multiplet, while the other states with the same $I,J^{PC}$ are members of the other parity-chiral multiplet. For example, while some of the excited $\rho(1,1^{--})$ states are systematically degenerate with $a_1(1,1^{++})$ states forming (0,1)+(1,0) chiral multiplets, the other excited $\rho(1,1^{--})$ states are degenerate with $h_1(0,1^{+-})$ states ((1/2,1/2) chiral multiplets). Hence, one of the predictions of chiral symmetry restoration is that the combined amount of $a_1(1,1^{++})$ and $h_1(0,1^{+-})$ states must coincide with the amount of $\rho(1,1^{--})$ states in the chirally restored regime. It is shown that the same rule applies (and experimentally confirmed) to many other meson states.
[ { "created": "Mon, 29 Dec 2003 14:06:57 GMT", "version": "v1" }, { "created": "Thu, 5 Feb 2004 11:37:39 GMT", "version": "v2" } ]
2008-11-26
[ [ "Glozman", "L. Ya.", "" ] ]
It is shown that experimental meson states with spins J=0,1,2,3 in the energy range 1.9 - 2.4 GeV obtained in recent partial wave analysis of proton-antiproton annihilation at LEAR remarkably confirm all predictions of chiral symmetry restoration. Classification of excited $\bar q q$ mesons according to the representations of chiral $U(2)_L \times U(2)_R$ group is performed. There are two important predictions of chiral symmetry restoration in highly excited mesons: (i) physical states must fill out approximately degenerate parity-chiral multiplets; (ii) some of the physical states with the given $I,J^{PC}$ are members of one parity-chiral multiplet, while the other states with the same $I,J^{PC}$ are members of the other parity-chiral multiplet. For example, while some of the excited $\rho(1,1^{--})$ states are systematically degenerate with $a_1(1,1^{++})$ states forming (0,1)+(1,0) chiral multiplets, the other excited $\rho(1,1^{--})$ states are degenerate with $h_1(0,1^{+-})$ states ((1/2,1/2) chiral multiplets). Hence, one of the predictions of chiral symmetry restoration is that the combined amount of $a_1(1,1^{++})$ and $h_1(0,1^{+-})$ states must coincide with the amount of $\rho(1,1^{--})$ states in the chirally restored regime. It is shown that the same rule applies (and experimentally confirmed) to many other meson states.
2001.05884
Feng-Kun Guo
Feng-Kun Guo
Triangle Singularities and Charmonium-like $XYZ$ States
15 pages, 5 figures; conference proceedings for the 17th Chinese Nuclear Physics Conference; published version
Nucl. Phys. Rev. 37 (2020) 406-413
10.11804/NuclPhysRev.37.2019CNPC52
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectrum of hadrons is important for understanding the confinement of quantum chromodynamics. Many new puzzles arose since 2003 due to the abundance of experimental discoveries with the $XYZ$ structures in the heavy quarkonium mass region being the outstanding examples. Hadronic resonances correspond to poles of the $S$-matrix, which has other types of singularities such as the triangle singularity due to the simultaneous on-shellness of three intermediate particles. Here we briefly discuss a few possible manifestations of triangle singularities in the $XYZ$ physics, paying particular attention to the formalism that can be used to analyze the data for charged $Z_c$ structures in the $\psi\pi$ distributions of the reaction $e^+e^-\to \psi\pi^+\pi^-$.
[ { "created": "Thu, 16 Jan 2020 15:19:27 GMT", "version": "v1" }, { "created": "Mon, 1 Mar 2021 01:12:29 GMT", "version": "v2" } ]
2021-03-02
[ [ "Guo", "Feng-Kun", "" ] ]
The spectrum of hadrons is important for understanding the confinement of quantum chromodynamics. Many new puzzles arose since 2003 due to the abundance of experimental discoveries with the $XYZ$ structures in the heavy quarkonium mass region being the outstanding examples. Hadronic resonances correspond to poles of the $S$-matrix, which has other types of singularities such as the triangle singularity due to the simultaneous on-shellness of three intermediate particles. Here we briefly discuss a few possible manifestations of triangle singularities in the $XYZ$ physics, paying particular attention to the formalism that can be used to analyze the data for charged $Z_c$ structures in the $\psi\pi$ distributions of the reaction $e^+e^-\to \psi\pi^+\pi^-$.
1703.00912
Matthew Low
Marco Farina, Matthew Low
Constraining Quirky Tracks with Conventional Searches
7 pages, 3 figures, 2 tables
Phys. Rev. Lett. 119, 111801 (2017)
10.1103/PhysRevLett.119.111801
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quirks are particles that are both charged under the standard model and under a new confining group. The quirk setup assumes there are no light flavors of the new confining group so that while the theory is in a confining phase, the distance between quirk-antiquirk pairs can be macroscopic. In this work, we reinterpret existing collider limits, those from monojet and heavy stable charged particle searches, as limits on quirks. Additionally, we propose a new search in the magnetic-field-less CMS data for quirks and estimate the sensitivity. We focus on the region where the confinement scale is roughly between 1 eV and 100 eV and find mass constraints in the TeV-range, depending on the quirk's quantum numbers.
[ { "created": "Thu, 2 Mar 2017 19:00:04 GMT", "version": "v1" } ]
2017-09-20
[ [ "Farina", "Marco", "" ], [ "Low", "Matthew", "" ] ]
Quirks are particles that are both charged under the standard model and under a new confining group. The quirk setup assumes there are no light flavors of the new confining group so that while the theory is in a confining phase, the distance between quirk-antiquirk pairs can be macroscopic. In this work, we reinterpret existing collider limits, those from monojet and heavy stable charged particle searches, as limits on quirks. Additionally, we propose a new search in the magnetic-field-less CMS data for quirks and estimate the sensitivity. We focus on the region where the confinement scale is roughly between 1 eV and 100 eV and find mass constraints in the TeV-range, depending on the quirk's quantum numbers.
hep-ph/9803277
Georg Weiglein
S. Heinemeyer, W. Hollik and G. Weiglein
QCD Corrections to the Masses of the neutral CP-even Higgs Bosons in the MSSM
9 pages, 4 figures, more detailed discussion about comparison with other approaches, minor further changes, version to appear in Phys. Rev. D Rapid Comm
Phys.Rev.D58:091701,1998
10.1103/PhysRevD.58.091701
KA-TP-2-1998
hep-ph
null
We perform a diagrammatic calculation of the leading two-loop QCD corrections to the masses of the neutral CP-even Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM). The results are valid for arbitrary values of the parameters of the Higgs and scalar top sector of the MSSM. The two-loop corrections are found to reduce the mass of the lightest Higgs boson considerably compared to its one-loop value. The numerical results are analyzed in the GUT favored regions of small and large \tan \beta. Their impact on a precise prediction for the mass of the lightest Higgs boson is briefly discussed.
[ { "created": "Sun, 8 Mar 1998 14:29:48 GMT", "version": "v1" }, { "created": "Tue, 25 Aug 1998 16:18:07 GMT", "version": "v2" } ]
2009-12-30
[ [ "Heinemeyer", "S.", "" ], [ "Hollik", "W.", "" ], [ "Weiglein", "G.", "" ] ]
We perform a diagrammatic calculation of the leading two-loop QCD corrections to the masses of the neutral CP-even Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM). The results are valid for arbitrary values of the parameters of the Higgs and scalar top sector of the MSSM. The two-loop corrections are found to reduce the mass of the lightest Higgs boson considerably compared to its one-loop value. The numerical results are analyzed in the GUT favored regions of small and large \tan \beta. Their impact on a precise prediction for the mass of the lightest Higgs boson is briefly discussed.
1202.2632
Azad Inshalla oglu Ahmadov
A. I. Ahmadov, C. Aydin, F. Keskin
Pion wave functions from holographic QCD and the role of infrared renormalons in photon-photon collisions
21 pages, 15 figures. arXiv admin note: text overlap with arXiv:0709.2072 by other authors
Phys. Rev. D85, 034009, 2012
10.1103/PhysRevD.85.034009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we calculate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive single pion production cross section in photon-photon collisions in case of the running coupling and frozen coupling approaches within holographic QCD. We compare the resummed higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. Also, we show that in the context of frozen coupling approach a higher-twist contribution to the photon-photon collisions cross section is normalized in terms of the pion electromagnetic form factor.
[ { "created": "Mon, 13 Feb 2012 05:49:30 GMT", "version": "v1" } ]
2015-06-04
[ [ "Ahmadov", "A. I.", "" ], [ "Aydin", "C.", "" ], [ "Keskin", "F.", "" ] ]
In this article, we calculate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive single pion production cross section in photon-photon collisions in case of the running coupling and frozen coupling approaches within holographic QCD. We compare the resummed higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. Also, we show that in the context of frozen coupling approach a higher-twist contribution to the photon-photon collisions cross section is normalized in terms of the pion electromagnetic form factor.
hep-ph/0208240
Roy Sourov
Debajyoti Choudhury (HRI, India), Dilip Kumar Ghosh (NCTS, Taiwan), Sourov Roy (Technion, Israel)
Signals of anomaly mediated supersymmetry breaking in an e^- gamma collider
25 pages, LaTex, 7 PS figures and 1 table (included)
Nucl.Phys. B646 (2002) 3-23
10.1016/S0550-3213(02)00902-1
MRI-P-020802
hep-ph
null
We study the signatures of minimal anomaly mediated supersymmetry breaking in an e^- gamma collider. We demonstrate that the associated production of a sneutrino with the lightest chargino leads to a substantially large signal size. The background is negligibly small, though. Even more interestingly, a measurement of the fundamental supersymmetry breaking parameters could be possible.
[ { "created": "Mon, 26 Aug 2002 18:09:19 GMT", "version": "v1" } ]
2010-04-05
[ [ "Choudhury", "Debajyoti", "", "HRI, India" ], [ "Ghosh", "Dilip Kumar", "", "NCTS, Taiwan" ], [ "Roy", "Sourov", "", "Technion, Israel" ] ]
We study the signatures of minimal anomaly mediated supersymmetry breaking in an e^- gamma collider. We demonstrate that the associated production of a sneutrino with the lightest chargino leads to a substantially large signal size. The background is negligibly small, though. Even more interestingly, a measurement of the fundamental supersymmetry breaking parameters could be possible.
hep-ph/0304144
Wolfgang Ochs
Peter Minkowski (Uni Bern) and Wolfgang Ochs (MPI Munich)
Scalar mesons and glueball in B-decays and gluon jets
13 pages
null
null
BUTP-03/10, MPI-PhT/2003-16
hep-ph
null
We discuss the recent observation of f_0(980) in charmless B-decays and in gluon jets which hints toward a gluonic coupling of this meson similar to eta'. Further predictions on B-decays into scalar particles are presented. Charmless B decays also show a broad K Kbar (and possibly pi pi) S-wave enhancement which we relate to the 0^{++} glueball. These gluonic mesons represent a sizable fraction of the theoretically derived decay rate for b -> sg.
[ { "created": "Tue, 15 Apr 2003 17:32:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Minkowski", "Peter", "", "Uni Bern" ], [ "Ochs", "Wolfgang", "", "MPI Munich" ] ]
We discuss the recent observation of f_0(980) in charmless B-decays and in gluon jets which hints toward a gluonic coupling of this meson similar to eta'. Further predictions on B-decays into scalar particles are presented. Charmless B decays also show a broad K Kbar (and possibly pi pi) S-wave enhancement which we relate to the 0^{++} glueball. These gluonic mesons represent a sizable fraction of the theoretically derived decay rate for b -> sg.
hep-ph/9411255
Alessandro Strumia
R. Barbieri, P. Ciafaloni and A. Strumia
Light thresholds in Grand Unified Theories
8 pages; all figures are now included in a uuencoded file
Nucl.Phys.B442:461-471,1995
10.1016/0550-3213(95)00127-E
IFUP -- TH 47/94
hep-ph
null
In a generic Grand Unified Theory with a relatively small dispersion of the spectrum around the $Z$-boson and the unification masses, a connection is established, exact at one loop level, between $M_Z$, $G_{\rm F}$, $\alpha(M_Z)$ and the strong coupling constant $\alpha_3(M_Z)$. At this level of precision, this avoids the logical and phenomenological inconsistency of predicting $\alpha_3(M_Z)$ by means of the electroweak couplings as extracted from the data in the Standard Model rather than in the complete theory. Attention is paid to the independence of the physical results from regularization and/or renormalization schemes. As a particularly relevant example, the analysis is specialized to the case of the Minimal Supersymmetric Standard Model, with emphasis on light charginos and neutralinos.
[ { "created": "Wed, 9 Nov 1994 16:43:11 GMT", "version": "v1" }, { "created": "Mon, 7 Aug 1995 10:59:33 GMT", "version": "v2" } ]
2009-10-09
[ [ "Barbieri", "R.", "" ], [ "Ciafaloni", "P.", "" ], [ "Strumia", "A.", "" ] ]
In a generic Grand Unified Theory with a relatively small dispersion of the spectrum around the $Z$-boson and the unification masses, a connection is established, exact at one loop level, between $M_Z$, $G_{\rm F}$, $\alpha(M_Z)$ and the strong coupling constant $\alpha_3(M_Z)$. At this level of precision, this avoids the logical and phenomenological inconsistency of predicting $\alpha_3(M_Z)$ by means of the electroweak couplings as extracted from the data in the Standard Model rather than in the complete theory. Attention is paid to the independence of the physical results from regularization and/or renormalization schemes. As a particularly relevant example, the analysis is specialized to the case of the Minimal Supersymmetric Standard Model, with emphasis on light charginos and neutralinos.
1412.1247
Marc Knecht
V\'eronique Bernard, S\'ebastien Descotes-Genon, Marc Knecht
Isospin breaking in pion and $K_{e4}$ form factors
15 pages, 3 figures, prepared for the proceedings of the XIth Confinement and Hadron Spectrum Conference, Saint-Petersburg, Sept. 8-12, 2014
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Isospin breaking in the $K_{\ell 4}$ form factors induced by the difference between charged and neutral pion masses is discussed within a framework built on suitably subtracted dispersion representations. The $K_{\ell 4}$ form factors are constructed in an iterative way up to two loops in the low-energy expansion by implementing analyticity, crossing, and unitarity due to two-meson intermediate states. Analytical expressions for the phases of the two-loop form factors of the $K^\pm\to\pi^+\pi^- e^\pm \nu_e$ channel are presented, allowing one to connect the difference of form-factor phase shifts measured experimentally (out of the isospin limit) and the difference of $S$- and $P$-wave $\pi\pi$ phase shifts studied theoretically (in the isospin limit). The dependence with respect to the two $S$-wave scattering lengths $a_0^0$ and $a_0^2$ in the isospin limit is worked out in a general way, in contrast to previous analyses based on one-loop chiral perturbation theory. The results on the phases of the $K^\pm\to\pi^+\pi^- e^\pm \nu_e$ form factors obtained by the NA48/2 collaboration at the CERN SPS are reanalysed including isospin-breaking correction to extract values for the scattering lengths $a_0^0$ and $a_0^2$.
[ { "created": "Wed, 3 Dec 2014 09:35:54 GMT", "version": "v1" } ]
2014-12-04
[ [ "Bernard", "Véronique", "" ], [ "Descotes-Genon", "Sébastien", "" ], [ "Knecht", "Marc", "" ] ]
Isospin breaking in the $K_{\ell 4}$ form factors induced by the difference between charged and neutral pion masses is discussed within a framework built on suitably subtracted dispersion representations. The $K_{\ell 4}$ form factors are constructed in an iterative way up to two loops in the low-energy expansion by implementing analyticity, crossing, and unitarity due to two-meson intermediate states. Analytical expressions for the phases of the two-loop form factors of the $K^\pm\to\pi^+\pi^- e^\pm \nu_e$ channel are presented, allowing one to connect the difference of form-factor phase shifts measured experimentally (out of the isospin limit) and the difference of $S$- and $P$-wave $\pi\pi$ phase shifts studied theoretically (in the isospin limit). The dependence with respect to the two $S$-wave scattering lengths $a_0^0$ and $a_0^2$ in the isospin limit is worked out in a general way, in contrast to previous analyses based on one-loop chiral perturbation theory. The results on the phases of the $K^\pm\to\pi^+\pi^- e^\pm \nu_e$ form factors obtained by the NA48/2 collaboration at the CERN SPS are reanalysed including isospin-breaking correction to extract values for the scattering lengths $a_0^0$ and $a_0^2$.
1208.5636
Aurore Courtoy
A. Courtoy, Simonetta Liuti
The Strong Coupling Constant from Hadron Structure Phenomenology
To appear in the proceedings of the QCD Evolution Workshop, JLab, May 14-17, 2012. Includes ws-ijmpcs.cls
null
10.1142/S2010194512009312
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present recent developments on the role of the running coupling constant at the intersection of perturbative and nonperturbative QCD. A number of experiments show a smooth transition from small to large scales given by the four-momentum transfer in the reactions. This is at variance with perturbative QCD where the running coupling constant becomes infinite when the scale equals $\Lambda_{{\tiny QCD}}$. Approaches using an effective coupling constant could help interpret the opposite trend of data as compared to standard perturbative QCD predictions. We give an overview of the role of the coupling constant in the procedure to match nonperturbative hadronic model to perturbative QCD and we propose an extraction of an effective coupling constant from inclusive electron proton scattering data at large Bjorken x.
[ { "created": "Tue, 28 Aug 2012 12:12:45 GMT", "version": "v1" } ]
2015-06-11
[ [ "Courtoy", "A.", "" ], [ "Liuti", "Simonetta", "" ] ]
We present recent developments on the role of the running coupling constant at the intersection of perturbative and nonperturbative QCD. A number of experiments show a smooth transition from small to large scales given by the four-momentum transfer in the reactions. This is at variance with perturbative QCD where the running coupling constant becomes infinite when the scale equals $\Lambda_{{\tiny QCD}}$. Approaches using an effective coupling constant could help interpret the opposite trend of data as compared to standard perturbative QCD predictions. We give an overview of the role of the coupling constant in the procedure to match nonperturbative hadronic model to perturbative QCD and we propose an extraction of an effective coupling constant from inclusive electron proton scattering data at large Bjorken x.
hep-ph/9410347
Chao-Qiang GengT
C.Q. Geng and S.K. Lee
Analysis of Transverse Muon Polarization in $K^+\to \pi^0\mu^+\nu$ and $K^+\to \mu^+\nu\gamma$ Decays with Tensor Interactions
13 pages (LaTex), 3 figures (not included), NHCU-HEP-94-03
Phys.Rev. D51 (1995) 99-102
10.1103/PhysRevD.51.99
null
hep-ph
null
The T violating transverse muon polarizations in $K^+\to \pi^0\mu^+\nu$ and $K^+\to \mu^+\nu\gamma$ decays due to tensor interactions are studied. The magnitudes of these polarizations over the allowed phase space are presented.
[ { "created": "Sat, 22 Oct 1994 13:35:21 GMT", "version": "v1" } ]
2009-10-28
[ [ "Geng", "C. Q.", "" ], [ "Lee", "S. K.", "" ] ]
The T violating transverse muon polarizations in $K^+\to \pi^0\mu^+\nu$ and $K^+\to \mu^+\nu\gamma$ decays due to tensor interactions are studied. The magnitudes of these polarizations over the allowed phase space are presented.
2103.12099
Andrea Caputo
Jos\'e Luis Bernal, Andrea Caputo, Francisco Villaescusa-Navarro, Marc Kamionkowski
Detecting the radiative decay of the cosmic neutrino background with line-intensity mapping
Version published in PRL
Phys. Rev. Lett. 127, 131102 (2021)
10.1103/PhysRevLett.127.131102
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility to use line-intensity mapping (LIM) to seek photons from the radiative decay of neutrinos in the cosmic neutrino background. The Standard Model prediction for the rate for these decays is extremely small, but it can be enhanced if new physics increases the neutrino electromagnetic moments. The decay photons will appear as an interloper of astrophysical spectral lines. We propose that the neutrino-decay line can be identified with anisotropies in LIM clustering and also with the voxel intensity distribution. Ongoing and future LIM experiments will have -- depending on the neutrino hierarchy, transition and experiment considered -- a sensitivity to an effective electromagnetic transition moment $\sim 10^{-12}\, -\,10^{-8}\, (m_ic^2/{0.1 \rm eV})^{3/2}\mu_{\rm B}$, where $m_i$ is the mass of the decaying neutrino and $\mu_{\rm B}$ is the Bohr magneton. This will be significantly more sensitive than cosmic microwave background spectral distortions, and it will be competitive with stellar cooling studies. As a byproduct, we also report an analytic form of the one-point probability distribution function for neutrino-density fluctuations, obtained from the Quijote simulations using symbolic regression.
[ { "created": "Mon, 22 Mar 2021 18:01:41 GMT", "version": "v1" }, { "created": "Fri, 22 Oct 2021 14:43:50 GMT", "version": "v2" } ]
2021-10-25
[ [ "Bernal", "José Luis", "" ], [ "Caputo", "Andrea", "" ], [ "Villaescusa-Navarro", "Francisco", "" ], [ "Kamionkowski", "Marc", "" ] ]
We study the possibility to use line-intensity mapping (LIM) to seek photons from the radiative decay of neutrinos in the cosmic neutrino background. The Standard Model prediction for the rate for these decays is extremely small, but it can be enhanced if new physics increases the neutrino electromagnetic moments. The decay photons will appear as an interloper of astrophysical spectral lines. We propose that the neutrino-decay line can be identified with anisotropies in LIM clustering and also with the voxel intensity distribution. Ongoing and future LIM experiments will have -- depending on the neutrino hierarchy, transition and experiment considered -- a sensitivity to an effective electromagnetic transition moment $\sim 10^{-12}\, -\,10^{-8}\, (m_ic^2/{0.1 \rm eV})^{3/2}\mu_{\rm B}$, where $m_i$ is the mass of the decaying neutrino and $\mu_{\rm B}$ is the Bohr magneton. This will be significantly more sensitive than cosmic microwave background spectral distortions, and it will be competitive with stellar cooling studies. As a byproduct, we also report an analytic form of the one-point probability distribution function for neutrino-density fluctuations, obtained from the Quijote simulations using symbolic regression.
hep-ph/9606247
Isi Dunietz
Isard Dunietz (Fermilab)
On the Necessity of Recalibrating Heavy Flavor Decays and its Impact on Apparent Puzzles in High Energy Physics
60 pages, RevTex
null
null
FERMILAB--PUB--96/104--T
hep-ph
null
It is demonstrated that charm is systematically undercounted in various experiments. Via a process of elimination, $B(D^0 \rightarrow K^- \pi^+ )$ is identified as the culprit. It calibrates essentially all charmed meson production and decay properties, and thus is central to the physics of heavy flavors. We predict it to decrease significantly below currently accepted values. We suggest several novel methods for precise measurements of $B(D^0 \rightarrow K^- \pi^+ )$. The $B(\Lambda_c \rightarrow pK^-\pi^+)$, on the other hand, calibrates heavy-flavored baryons. Its world average relies heavily on a model of baryon production in $B$ decays, which would be invalidated if $\overline B\rightarrow D^{(*)} \stackrel{(-)}{N} X$ processes were found to be significant. A Dalitz-plot analysis explains naturally the soft inclusive $\Lambda_c$ momentum spectrum in $\overline B$ decays, and predicts sizable $\overline B\rightarrow D^{(*)}\stackrel{(-)}{N} X$ processes. Consistently carrying through these modifications to charmed meson and baryon yields has the potential to resolve the heavy-flavor puzzles at $Z^0$-factories [$R_c,\; R_b$], the number of charm per $B$-decay puzzle, and the semi-leptonic $B$ decay puzzles. We emphasize that state of the art theoretical calculations are consistent with precise experimental measurements regarding $B(\overline B\rightarrow X\ell\bar\nu )$. Recent CLEO measurements are interpreted as newly available cross-checks that any inclusive theoretical investigation must satisfy. Another topic of this report concerns the $b\rightarrow c + \overline D^{(*)}\overline K$ transitions, which were predicted to be sizable and subsequently confirmed by CLEO. This report discusses the underlying dynamics of those processes and quantifies the necessary modifications in existing
[ { "created": "Wed, 5 Jun 1996 20:45:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dunietz", "Isard", "", "Fermilab" ] ]
It is demonstrated that charm is systematically undercounted in various experiments. Via a process of elimination, $B(D^0 \rightarrow K^- \pi^+ )$ is identified as the culprit. It calibrates essentially all charmed meson production and decay properties, and thus is central to the physics of heavy flavors. We predict it to decrease significantly below currently accepted values. We suggest several novel methods for precise measurements of $B(D^0 \rightarrow K^- \pi^+ )$. The $B(\Lambda_c \rightarrow pK^-\pi^+)$, on the other hand, calibrates heavy-flavored baryons. Its world average relies heavily on a model of baryon production in $B$ decays, which would be invalidated if $\overline B\rightarrow D^{(*)} \stackrel{(-)}{N} X$ processes were found to be significant. A Dalitz-plot analysis explains naturally the soft inclusive $\Lambda_c$ momentum spectrum in $\overline B$ decays, and predicts sizable $\overline B\rightarrow D^{(*)}\stackrel{(-)}{N} X$ processes. Consistently carrying through these modifications to charmed meson and baryon yields has the potential to resolve the heavy-flavor puzzles at $Z^0$-factories [$R_c,\; R_b$], the number of charm per $B$-decay puzzle, and the semi-leptonic $B$ decay puzzles. We emphasize that state of the art theoretical calculations are consistent with precise experimental measurements regarding $B(\overline B\rightarrow X\ell\bar\nu )$. Recent CLEO measurements are interpreted as newly available cross-checks that any inclusive theoretical investigation must satisfy. Another topic of this report concerns the $b\rightarrow c + \overline D^{(*)}\overline K$ transitions, which were predicted to be sizable and subsequently confirmed by CLEO. This report discusses the underlying dynamics of those processes and quantifies the necessary modifications in existing
hep-ph/9804292
Fumiaki Araki Quark Nuclear Physics Group
Fumiaki Araki, Hideo Suganuma, Hiroshi Toki (RCNP, Osaka Univ.)
Behavior of monopole trajectories in the instanton and anti-instanton system at finite temperature
Talk presented by F. Araki at ``INNOCOM '97'', XVII RCNP the International Symposium on Innovative Computational Methods in Nuclear Many-Body Problems, Osaka, Japan, 10 - 15 November 1997. LaTeX, uses epsbox.sty and sprocl.sty, 3 pages, 2 figures included
null
null
null
hep-ph
null
We study the connection between monopoles and instantons in the Polyakov-like gauge, and the behavior of the monopole trajectories generated by instantons at finite temperature. The monopole trajectories become long and complicated at the zero-temperature which can be regarded as monopole condensation. On the other hand, they tend to become simple at finite temperature. It is suggested that such a change is related to the confinement-deconfinement phase transition.
[ { "created": "Wed, 15 Apr 1998 07:54:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Araki", "Fumiaki", "", "RCNP, Osaka Univ." ], [ "Suganuma", "Hideo", "", "RCNP, Osaka Univ." ], [ "Toki", "Hiroshi", "", "RCNP, Osaka Univ." ] ]
We study the connection between monopoles and instantons in the Polyakov-like gauge, and the behavior of the monopole trajectories generated by instantons at finite temperature. The monopole trajectories become long and complicated at the zero-temperature which can be regarded as monopole condensation. On the other hand, they tend to become simple at finite temperature. It is suggested that such a change is related to the confinement-deconfinement phase transition.
hep-ph/0510097
Dan Hooper
Dan Hooper
Probing Exotic Physics With Cosmic Neutrinos
11 pages, 6 figures; For the proceedings of From Colliders To Cosmic Rays, Prague, Czech Republic, September 7-13, 2005
Czech.J.Phys.56:A337-A347,2006
10.1007/s10582-006-0167-6
FERMILAB-CONF-05-421-A
hep-ph astro-ph
null
Traditionally, collider experiments have been the primary tool used in searching for particle physics beyond the Standard Model. In this talk, I will discuss alternative approaches for exploring exotic physics scenarios using high energy and ultra-high energy cosmic neutrinos. Such neutrinos can be used to study interactions at energies higher, and over baselines longer, than those accessible to colliders. In this way, neutrino astronomy can provide a window into fundamental physics which is highly complementary to collider techniques. I will discuss the role of neutrino astronomy in fundamental physics, considering the use of such techniques in studying several specific scenarios including low scale gravity models, Standard Model electroweak instanton induced interactions, decaying neutrinos and quantum decoherence.
[ { "created": "Fri, 7 Oct 2005 16:24:11 GMT", "version": "v1" } ]
2014-11-18
[ [ "Hooper", "Dan", "" ] ]
Traditionally, collider experiments have been the primary tool used in searching for particle physics beyond the Standard Model. In this talk, I will discuss alternative approaches for exploring exotic physics scenarios using high energy and ultra-high energy cosmic neutrinos. Such neutrinos can be used to study interactions at energies higher, and over baselines longer, than those accessible to colliders. In this way, neutrino astronomy can provide a window into fundamental physics which is highly complementary to collider techniques. I will discuss the role of neutrino astronomy in fundamental physics, considering the use of such techniques in studying several specific scenarios including low scale gravity models, Standard Model electroweak instanton induced interactions, decaying neutrinos and quantum decoherence.
hep-ph/9503326
null
M. Gourdin, Y. Y. Keum, and X. Y. Pham
A Model for the decay of the $D_s^{+}$ meson into three pions,
23 pages (Latex) including 7 figures (Postscript file).
Phys.Rev. D53 (1996) 3687-3699
10.1103/PhysRevD.53.3687
Preprint PAR/LPTHE/95-09
hep-ph
null
We propose a phenomenological two component model describing the decay amplitude of the process $D_s^{+} \ra 3 \pi$, whose rate has been found surprisingly large. The first component is a constant background $F_{NR}$, and the second one is a Breit-Wigner type amplitude associated to a quasi two body $f_0(980)$ $\pi^{+}$ state. We show that it is possible to reproduce the observed rate for $D_s^{+} \ra \pi^{+}\pi^{+}\pi^{-}$ as well as the two other measured branching ratios for the non resonant part and the resonant $f_0\pi^{+}$ one, with a common parameter $F_{NR}$. Predictions are given for the $D_s^{+} \ra \pi^{0}\pi^{0}\pi^{+}$ rates, as well as for the various $\pi^{+}$ and $\pi^{-}$, or $\pi^{0}$ and $\pi^{+}$ energy distributions for the two possible final states.
[ { "created": "Tue, 14 Mar 1995 14:38:49 GMT", "version": "v1" } ]
2015-06-25
[ [ "Gourdin", "M.", "" ], [ "Keum", "Y. Y.", "" ], [ "Pham", "X. Y.", "" ] ]
We propose a phenomenological two component model describing the decay amplitude of the process $D_s^{+} \ra 3 \pi$, whose rate has been found surprisingly large. The first component is a constant background $F_{NR}$, and the second one is a Breit-Wigner type amplitude associated to a quasi two body $f_0(980)$ $\pi^{+}$ state. We show that it is possible to reproduce the observed rate for $D_s^{+} \ra \pi^{+}\pi^{+}\pi^{-}$ as well as the two other measured branching ratios for the non resonant part and the resonant $f_0\pi^{+}$ one, with a common parameter $F_{NR}$. Predictions are given for the $D_s^{+} \ra \pi^{0}\pi^{0}\pi^{+}$ rates, as well as for the various $\pi^{+}$ and $\pi^{-}$, or $\pi^{0}$ and $\pi^{+}$ energy distributions for the two possible final states.
1906.09229
Jose Bordes
Jos\'e BORDES (1), CHAN Hong-Mo (2) and TSOU Sheung Tsun (3) ((1) Departament Fisica Teorica and IFIC, CSIC-Universitat de Valencia, Spain, (2) Rutherford Appleton Laboratory, United Kingdom, (3) Mathematical Institute, University of Oxford, United Kingdom)
Accommodating three low-scale anomalies (g-2, Lamb shift, and Atomki) in the framed standard model
null
null
10.1142/S0217751X19501409
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The framed standard model (FSM) predicts a $0^+$ boson with mass around 20 MeV in the "hidden sector", which mixes at tree level with the standard Higgs $h_W$ and hence acquires small couplings to quarks and leptons which can be calculated in the FSM apart from the mixing parameter $\rho_{Uh}$. The exchange of this mixed state $U$ will contribute to $g - 2$ and to the Lamb shift. By adjusting $\rho_{Uh}$ alone, it is found that the FSM can satisfy all present experimental bounds on the $g - 2$ and Lamb shift anomalies for $\mu$ and $e$, and for the latter for both hydrogen and deuterium. The FSM predicts also a $1^-$ boson in the "hidden sector" with a mass of 17 MeV, that is, right on top of the Atomki anomaly $X$. This mixes with the photon at 1-loop level and couples thereby like a dark photon to quarks and leptons. It is however a compound state and is thought likely to possess additional compound couplings to hadrons. By adjusting the mixing parameter and the $X$'s compound coupling to nucleons, the FSM can reproduce the production rate of the $X$ in beryllium decay as well as satisfy all the bounds on $X$ listed so far in the literature. The above two results are consistent in that the $U$, being $0^+$, does not contribute to the Atomki anomaly if parity and angular momentum are conserved, while $X$, though contributing to $g - 2$ and Lamb shift, has smaller couplings than $U$ and can, at first instance, be neglected there. Despite the tentative nature of the 3 anomalies in experiment and of the FSM as theory, the accommodation of the former in the latter has strengthened the credibility of both. If this FSM interpretation were correct, it would change the whole aspect of the anomalies from just curiosities to windows into a vast hitherto hidden sector comprising at least in part the dark matter which makes up the bulk of our universe.
[ { "created": "Fri, 21 Jun 2019 16:31:20 GMT", "version": "v1" } ]
2019-09-25
[ [ "BORDES", "José", "" ], [ "Hong-Mo", "CHAN", "" ], [ "Tsun", "TSOU Sheung", "" ] ]
The framed standard model (FSM) predicts a $0^+$ boson with mass around 20 MeV in the "hidden sector", which mixes at tree level with the standard Higgs $h_W$ and hence acquires small couplings to quarks and leptons which can be calculated in the FSM apart from the mixing parameter $\rho_{Uh}$. The exchange of this mixed state $U$ will contribute to $g - 2$ and to the Lamb shift. By adjusting $\rho_{Uh}$ alone, it is found that the FSM can satisfy all present experimental bounds on the $g - 2$ and Lamb shift anomalies for $\mu$ and $e$, and for the latter for both hydrogen and deuterium. The FSM predicts also a $1^-$ boson in the "hidden sector" with a mass of 17 MeV, that is, right on top of the Atomki anomaly $X$. This mixes with the photon at 1-loop level and couples thereby like a dark photon to quarks and leptons. It is however a compound state and is thought likely to possess additional compound couplings to hadrons. By adjusting the mixing parameter and the $X$'s compound coupling to nucleons, the FSM can reproduce the production rate of the $X$ in beryllium decay as well as satisfy all the bounds on $X$ listed so far in the literature. The above two results are consistent in that the $U$, being $0^+$, does not contribute to the Atomki anomaly if parity and angular momentum are conserved, while $X$, though contributing to $g - 2$ and Lamb shift, has smaller couplings than $U$ and can, at first instance, be neglected there. Despite the tentative nature of the 3 anomalies in experiment and of the FSM as theory, the accommodation of the former in the latter has strengthened the credibility of both. If this FSM interpretation were correct, it would change the whole aspect of the anomalies from just curiosities to windows into a vast hitherto hidden sector comprising at least in part the dark matter which makes up the bulk of our universe.
2111.11117
Massimo Mannarelli
Massimo Mannarelli, Fabrizio Canfora, Stefano Carignano, Marcela Lagos and Aldo Vera
Inhomogeneous pion condensed phase hosting topologically stable baryons
8 pages, 4 figures, contribution to the proceedings of "A Virtual Tribute to Quark Confinement and the Hadron Spectrum" August 2nd-6th 2021 (online)
null
10.1051/epjconf/202225807003
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the inhomogeneous pion condensed phase within the framework of chiral perturbation theory. We show how the general expression of the condensate can be obtained solving three coupled differential equations, expressing how the pion fields are modulated in space. Upon using some simplifying assumptions, we determine an analytic solution in (3+1)-dimensions. The obtained inhomogeneous condensate is characterized by a non-vanishing topological charge, which can be identified with the baryonic number. In this way, we obtain an inhomogeneous system of pions hosting an arbitrary number of baryons at fixed positions in space.
[ { "created": "Mon, 22 Nov 2021 11:18:02 GMT", "version": "v1" } ]
2022-02-16
[ [ "Mannarelli", "Massimo", "" ], [ "Canfora", "Fabrizio", "" ], [ "Carignano", "Stefano", "" ], [ "Lagos", "Marcela", "" ], [ "Vera", "Aldo", "" ] ]
We discuss the inhomogeneous pion condensed phase within the framework of chiral perturbation theory. We show how the general expression of the condensate can be obtained solving three coupled differential equations, expressing how the pion fields are modulated in space. Upon using some simplifying assumptions, we determine an analytic solution in (3+1)-dimensions. The obtained inhomogeneous condensate is characterized by a non-vanishing topological charge, which can be identified with the baryonic number. In this way, we obtain an inhomogeneous system of pions hosting an arbitrary number of baryons at fixed positions in space.
2404.14091
Farid Taghinavaz
Roya Heydari, Farid Taghinavaz
Local univalence versus stability and causality in hydrodynamic models
24 pages, 10 figures, comments are welcome
null
null
null
hep-ph hep-th math-ph math.MP nucl-th
http://creativecommons.org/licenses/by/4.0/
Our main objective is to compare the analytic properties of hydrodynamic series with the stability and causality conditions applied to hydrodynamic modes. Analyticity, in this context, implies that the hydrodynamic series behaves as a univalent or single-valued function. Stability and causality adhere to physical constraints where hydrodynamic modes neither exhibit exponential growth nor travel faster than the speed of light. Through an examination of various hydrodynamic models, such as the Muller-Israel-Stewart (MIS) and the first-order hydro models like the BDNK (Bemfica-Disconzi-Noronha-Kovtun) model, we observe no new restrictions stemming from the analyticity limits in the shear channel of these models. However, local univalence is maintained in the sound channel of these models despite the global divergence of the hydrodynamic series. Notably, differences in the sound equations between the MIS and BDNK models lead to distinct analyticity limits. The MIS model's sound mode remains univalent at high momenta within a specific transport range. Conversely, in the BDNK model, the univalence of the sound mode extends to intermediate momenta across all stable and causal regions. Generally, the convergence radius is independent of univalence and the given dispersion relation predominantly influences their correlation. For second-order frequency dispersions, the relationship is precise, i.e. within the convergence radius, the hydro series demonstrates univalence. However, with higher-order dispersions, the hydro series is locally univalent within certain transport regions, which may fall within or outside the stable and causal zones.
[ { "created": "Mon, 22 Apr 2024 11:22:02 GMT", "version": "v1" } ]
2024-04-23
[ [ "Heydari", "Roya", "" ], [ "Taghinavaz", "Farid", "" ] ]
Our main objective is to compare the analytic properties of hydrodynamic series with the stability and causality conditions applied to hydrodynamic modes. Analyticity, in this context, implies that the hydrodynamic series behaves as a univalent or single-valued function. Stability and causality adhere to physical constraints where hydrodynamic modes neither exhibit exponential growth nor travel faster than the speed of light. Through an examination of various hydrodynamic models, such as the Muller-Israel-Stewart (MIS) and the first-order hydro models like the BDNK (Bemfica-Disconzi-Noronha-Kovtun) model, we observe no new restrictions stemming from the analyticity limits in the shear channel of these models. However, local univalence is maintained in the sound channel of these models despite the global divergence of the hydrodynamic series. Notably, differences in the sound equations between the MIS and BDNK models lead to distinct analyticity limits. The MIS model's sound mode remains univalent at high momenta within a specific transport range. Conversely, in the BDNK model, the univalence of the sound mode extends to intermediate momenta across all stable and causal regions. Generally, the convergence radius is independent of univalence and the given dispersion relation predominantly influences their correlation. For second-order frequency dispersions, the relationship is precise, i.e. within the convergence radius, the hydro series demonstrates univalence. However, with higher-order dispersions, the hydro series is locally univalent within certain transport regions, which may fall within or outside the stable and causal zones.
hep-ph/9810270
Bodo Lampe
Bodo Lampe and Ewald Reya
Spin Physics and Polarized Structure Functions
134 pages (latex) and 64 figures (eps)
Phys.Rept.332:1-163,2000
10.1016/S0370-1573(99)00100-3
MPI-PhT/98-23,DO-TH 98/02
hep-ph
null
A review on the theoretical aspects and the experimental results of polarized deep inelastic scattering and of other hard scattering processes is presented. The following items are discussed: longitudinally polarized structure functions, results from the SLAC and CERN polarization experiments, the QCD interpretation and the LO and NLO Q2-evolution of g1, the role of the polarized gluon density, the expectations for x-->0, sum rules, the first moment of the polarized structure function, the parametrizations of polarized parton densities, polarized jet, heavy quark and direct photon production, DIS semi-inclusive asymmetries and elastic neutrino-proton scattering, single and double spin asymmetries, structure functions for higher spin hadrons and nuclei, nonperturbative approaches, the transverse structure function g2, chiral-odd 'transversity' distributions.
[ { "created": "Wed, 7 Oct 1998 10:12:54 GMT", "version": "v1" } ]
2011-01-25
[ [ "Lampe", "Bodo", "" ], [ "Reya", "Ewald", "" ] ]
A review on the theoretical aspects and the experimental results of polarized deep inelastic scattering and of other hard scattering processes is presented. The following items are discussed: longitudinally polarized structure functions, results from the SLAC and CERN polarization experiments, the QCD interpretation and the LO and NLO Q2-evolution of g1, the role of the polarized gluon density, the expectations for x-->0, sum rules, the first moment of the polarized structure function, the parametrizations of polarized parton densities, polarized jet, heavy quark and direct photon production, DIS semi-inclusive asymmetries and elastic neutrino-proton scattering, single and double spin asymmetries, structure functions for higher spin hadrons and nuclei, nonperturbative approaches, the transverse structure function g2, chiral-odd 'transversity' distributions.
2306.10828
Xing-Yu Yang
Kenji Kadota, Jeong Han Kim, Pyungwon Ko, Xing-Yu Yang
Gravitational wave probes on self-interacting dark matter surrounding an intermediate mass black hole
12 pages, 7 figures, 1 table; matches the published version
Phys. Rev. D 109, 015022 (2024)
10.1103/PhysRevD.109.015022
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The presence of dark matter overdensities surrounding a black hole can influence the evolution of a binary system. The gravitational wave signals emitted by a black hole binary offer a promising means to probe the dark matter environments near a black hole. The dense region of dark matter can lead to the dephasing of gravitational waveforms, which can be detected by upcoming experiments such as the Laser Interferometer Space Antenna (LISA). The dark matter density profile around the black hole can vary for different dark matter models. Our study specifically investigates the impact of the ultralight self-interacting scalar dark matter (SIDM) on the gravitational wave signals emitted by black hole binaries. A distinctive characteristic of SIDM surrounding a black hole, as opposed to collisionless dark matter, is the formation of a soliton core. We perform a Fisher matrix analysis to estimate the size of the soliton and the corresponding SIDM parameter space that future LISA-like gravitational wave experiments can explore.
[ { "created": "Mon, 19 Jun 2023 10:19:00 GMT", "version": "v1" }, { "created": "Tue, 23 Jan 2024 01:09:07 GMT", "version": "v2" } ]
2024-01-24
[ [ "Kadota", "Kenji", "" ], [ "Kim", "Jeong Han", "" ], [ "Ko", "Pyungwon", "" ], [ "Yang", "Xing-Yu", "" ] ]
The presence of dark matter overdensities surrounding a black hole can influence the evolution of a binary system. The gravitational wave signals emitted by a black hole binary offer a promising means to probe the dark matter environments near a black hole. The dense region of dark matter can lead to the dephasing of gravitational waveforms, which can be detected by upcoming experiments such as the Laser Interferometer Space Antenna (LISA). The dark matter density profile around the black hole can vary for different dark matter models. Our study specifically investigates the impact of the ultralight self-interacting scalar dark matter (SIDM) on the gravitational wave signals emitted by black hole binaries. A distinctive characteristic of SIDM surrounding a black hole, as opposed to collisionless dark matter, is the formation of a soliton core. We perform a Fisher matrix analysis to estimate the size of the soliton and the corresponding SIDM parameter space that future LISA-like gravitational wave experiments can explore.
hep-ph/9209219
Geert Jan van Oldenborgh
J. Bl\"umlein, G. J. van Oldenborgh and R. R\"uckl
QCD and QED Corrections to Higgs Boson Production in Charged Current $ep$ Scattering
latex, 16 pages + 9 pages figures in PostScript (included)
Nucl.Phys. B395 (1993) 35-59
10.1016/0550-3213(93)90207-6
CERN-TH.6581/92, MPI-Ph/91-46, LMU-92/06
hep-ph
null
First order QCD and leading QED corrections to Higgs boson production in the channel $e^-p \to \nu H^0 X; H^0 \to b\bar{b}$ are calculated for the kinematical conditions at LEP $\otimes$ LHC ($\sqrt{s} = 1360 \GeV$) and the interesting mass range $80 < M_H < 150 \GeV$. In the DIS scheme the QCD corrections (not including the corrections to the branching ratio, which are well-known) are found to be about 1\% for the total cross section and $-13\%$ to $-10\%$ for the observable cross section as defined by appropriate cuts. The latter results depend on the definition of these cuts. The QED corrections amount to about $-5\%$. Also obtainable with anonymous ftp from gluon.hep.physik.uni-muenchen.de.
[ { "created": "Mon, 7 Sep 1992 13:33:56 GMT", "version": "v1" } ]
2009-10-22
[ [ "Blümlein", "J.", "" ], [ "van Oldenborgh", "G. J.", "" ], [ "Rückl", "R.", "" ] ]
First order QCD and leading QED corrections to Higgs boson production in the channel $e^-p \to \nu H^0 X; H^0 \to b\bar{b}$ are calculated for the kinematical conditions at LEP $\otimes$ LHC ($\sqrt{s} = 1360 \GeV$) and the interesting mass range $80 < M_H < 150 \GeV$. In the DIS scheme the QCD corrections (not including the corrections to the branching ratio, which are well-known) are found to be about 1\% for the total cross section and $-13\%$ to $-10\%$ for the observable cross section as defined by appropriate cuts. The latter results depend on the definition of these cuts. The QED corrections amount to about $-5\%$. Also obtainable with anonymous ftp from gluon.hep.physik.uni-muenchen.de.
0902.4501
Yoshio Koide
Yoshio Koide
Can Massless and Light Yukawaons be Harmless?
version accepted by IJMPA, 14 pages, no figure, title and presentation changed
null
10.1142/S0217751X10048068
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the so-called yukawaon model, where the effective Yukawa coupling constants Y_f^{eff} (f=e,\nu,u,d) are given by vacuum expectation values (VEVs) of gauge singlet scalars (yukawaons) Y_f with 3\times 3 components, i.e. Y_f^{eff}= y_f < Y_f>/\Lambda, massless (and light) scalars appear because a global flavor symmetry is assumed. In order to demonstrate whether such massless scalars in the yukawaon model are harmless or not, yukawaon masses are explicitly estimated, as an example, in the charged lepton sector.
[ { "created": "Thu, 26 Feb 2009 02:57:37 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 2009 09:56:46 GMT", "version": "v2" } ]
2015-05-13
[ [ "Koide", "Yoshio", "" ] ]
In the so-called yukawaon model, where the effective Yukawa coupling constants Y_f^{eff} (f=e,\nu,u,d) are given by vacuum expectation values (VEVs) of gauge singlet scalars (yukawaons) Y_f with 3\times 3 components, i.e. Y_f^{eff}= y_f < Y_f>/\Lambda, massless (and light) scalars appear because a global flavor symmetry is assumed. In order to demonstrate whether such massless scalars in the yukawaon model are harmless or not, yukawaon masses are explicitly estimated, as an example, in the charged lepton sector.
hep-ph/0102157
Utpal Chattopadhyay
Utpal Chattopadhyay and Pran Nath
Upper Limits on Sparticle Masses from g-2 and the Possibility for Discovery of Supersymmetry at Colliders and in Dark Matter Searches
4 pages. Large tan\beta cases included. To appear in Phys. Rev. Lett
Phys.Rev.Lett. 86 (2001) 5854-5857
10.1103/PhysRevLett.86.5854
TIFR/TH/01-05, CERN-TH/2001-043
hep-ph hep-th
null
We analyze the implications of the new physics effect seen in the $g-2$ Brookhaven measurement and show that if the effect arises from supersymmetry, then the sign of the Higgs mixing parameter $\mu$ is determined to be positive in the standard sign convention. Further, analyses within the minimal supergravity model show that the Brookhaven result leads to upper limits on the universal gaugino and scalar masses of $m_{1/2}\leq 800$ GeV and $m_0\leq 1.5$ TeV for $\tan\beta\leq 55$. Our analysis strongly suggests that supersymmetry via production of sparticles must be found at the Large Hadron Collider. Further, sign($\mu$) positive is favorable for the discovery of supersymmetric cold dark matter.
[ { "created": "Tue, 13 Feb 2001 22:57:50 GMT", "version": "v1" }, { "created": "Tue, 29 May 2001 19:58:23 GMT", "version": "v2" } ]
2009-11-07
[ [ "Chattopadhyay", "Utpal", "" ], [ "Nath", "Pran", "" ] ]
We analyze the implications of the new physics effect seen in the $g-2$ Brookhaven measurement and show that if the effect arises from supersymmetry, then the sign of the Higgs mixing parameter $\mu$ is determined to be positive in the standard sign convention. Further, analyses within the minimal supergravity model show that the Brookhaven result leads to upper limits on the universal gaugino and scalar masses of $m_{1/2}\leq 800$ GeV and $m_0\leq 1.5$ TeV for $\tan\beta\leq 55$. Our analysis strongly suggests that supersymmetry via production of sparticles must be found at the Large Hadron Collider. Further, sign($\mu$) positive is favorable for the discovery of supersymmetric cold dark matter.
1504.01740
Sunghoon Jung
Brian Batell, Sunghoon Jung
Probing Light Stops with Stoponium
35 pages, 33 figures. v2: references added
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive new limits on light stops from diboson resonance searches in the $\gamma\gamma$, $Z \gamma$, $ZZ$, $WW$ and $hh$ channels from the first run of the LHC. If the two-body decays of the light stop are mildly suppressed or kinematically forbidden, stoponium bound states will form in $pp$ collisions and subsequently decay via the pair annihilation of the constituent stops to diboson final states, yielding striking resonance signatures. Remarkably, we find that stoponium searches are highly complementary to direct collider searches and indirect probes of light stops such as Higgs coupling measurements. Using an empirical quarkonia potential model and including the first two $S$-wave stoponium states, we find that in the decoupling limit $m_{\widetilde t_1} \lesssim 130$ GeV is excluded for any value of the stop mixing angle and heavy stop mass by the combination of the latest resonance searches and the indirect constraints. The $\gamma \gamma$ searches are the most complementary to the indirect constraints, probing the stop "blind spot" parameter region in which the $h^0 \tilde t_1 \tilde t_1^*$ trilinear coupling is small. Interestingly, we also find that the $Z\gamma$ searches give a stronger constraint, $m_{\widetilde t_1} \lesssim 170$ GeV, if the stop is primarily left-handed. For a scenario with a bino LSP and stop NLSP, several gaps in the direct collider searches for stops can unambiguously be filled with the next run of the LHC. For a stop LSP decaying through an R-parity violating $UDD$ coupling, the stoponium searches can fill the gap 100 GeV $\lesssim m_{\tilde t_1} \lesssim 200$ GeV in the direct searches for couplings $\lambda" \lesssim 10^{-2}$.
[ { "created": "Tue, 7 Apr 2015 20:00:53 GMT", "version": "v1" }, { "created": "Wed, 3 Jun 2015 06:23:41 GMT", "version": "v2" } ]
2015-06-04
[ [ "Batell", "Brian", "" ], [ "Jung", "Sunghoon", "" ] ]
We derive new limits on light stops from diboson resonance searches in the $\gamma\gamma$, $Z \gamma$, $ZZ$, $WW$ and $hh$ channels from the first run of the LHC. If the two-body decays of the light stop are mildly suppressed or kinematically forbidden, stoponium bound states will form in $pp$ collisions and subsequently decay via the pair annihilation of the constituent stops to diboson final states, yielding striking resonance signatures. Remarkably, we find that stoponium searches are highly complementary to direct collider searches and indirect probes of light stops such as Higgs coupling measurements. Using an empirical quarkonia potential model and including the first two $S$-wave stoponium states, we find that in the decoupling limit $m_{\widetilde t_1} \lesssim 130$ GeV is excluded for any value of the stop mixing angle and heavy stop mass by the combination of the latest resonance searches and the indirect constraints. The $\gamma \gamma$ searches are the most complementary to the indirect constraints, probing the stop "blind spot" parameter region in which the $h^0 \tilde t_1 \tilde t_1^*$ trilinear coupling is small. Interestingly, we also find that the $Z\gamma$ searches give a stronger constraint, $m_{\widetilde t_1} \lesssim 170$ GeV, if the stop is primarily left-handed. For a scenario with a bino LSP and stop NLSP, several gaps in the direct collider searches for stops can unambiguously be filled with the next run of the LHC. For a stop LSP decaying through an R-parity violating $UDD$ coupling, the stoponium searches can fill the gap 100 GeV $\lesssim m_{\tilde t_1} \lesssim 200$ GeV in the direct searches for couplings $\lambda" \lesssim 10^{-2}$.
0808.0022
Elena Bratkovskaya
W. Cassing (U. Giessen) and E.L. Bratkovskaya (FIAS, U. Frankfurt)
Parton transport and hadronization from the dynamical quasiparticle point of view
9 pages, 8 figures, to be published in Phys. Rev. C
Phys.Rev.C78:034919,2008
10.1103/PhysRevC.78.034919
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hadronization of an expanding partonic fireball is studied within the Parton-Hadron-Strings Dynamics (PHSD) approach which is based on a dynamical quasiparticle model (DQPM) matched to reproduce lattice QCD results in thermodynamic equilibrium. Apart from strong parton interactions the expansion and development of collective flow is driven by strong gradients in the parton mean-fields. An analysis of the elliptic flow $v_2$ demonstrates a linear correlation with the spatial eccentricity $\epsilon$ as in case of ideal hydrodynamics. The hadronization occurs by quark-antiquark fusion or 3 quark/3 antiquark recombination which is described by covariant transition rates. Since the dynamical quarks become very massive, the formed resonant 'pre-hadronic' color-dipole states ($q\bar{q}$ or $qqq$) are of high invariant mass, too, and sequentially decay to the groundstate meson and baryon octets increasing the total entropy. This solves the entropy problem in hadronization in a natural way. The resulting particle ratios turn out to be in line with those from a grandcanonical partition function at temperature $T \approx 170$ MeV rather independent from the initial temperature and indicate an approximate strangeness equilibration.
[ { "created": "Thu, 31 Jul 2008 21:10:38 GMT", "version": "v1" }, { "created": "Fri, 12 Sep 2008 00:43:31 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cassing", "W.", "", "U. Giessen" ], [ "Bratkovskaya", "E. L.", "", "FIAS, U. Frankfurt" ] ]
The hadronization of an expanding partonic fireball is studied within the Parton-Hadron-Strings Dynamics (PHSD) approach which is based on a dynamical quasiparticle model (DQPM) matched to reproduce lattice QCD results in thermodynamic equilibrium. Apart from strong parton interactions the expansion and development of collective flow is driven by strong gradients in the parton mean-fields. An analysis of the elliptic flow $v_2$ demonstrates a linear correlation with the spatial eccentricity $\epsilon$ as in case of ideal hydrodynamics. The hadronization occurs by quark-antiquark fusion or 3 quark/3 antiquark recombination which is described by covariant transition rates. Since the dynamical quarks become very massive, the formed resonant 'pre-hadronic' color-dipole states ($q\bar{q}$ or $qqq$) are of high invariant mass, too, and sequentially decay to the groundstate meson and baryon octets increasing the total entropy. This solves the entropy problem in hadronization in a natural way. The resulting particle ratios turn out to be in line with those from a grandcanonical partition function at temperature $T \approx 170$ MeV rather independent from the initial temperature and indicate an approximate strangeness equilibration.
1103.1095
Qiang Zhao
Qian Wang, Xiao-Hai Liu, and Qiang Zhao
Open charm effects in $e^+e^-\to J/\psi \eta$, $J/\psi \pi^0$ and $\phi\eta_c$
Revised version to appear in PRD; An error corrected; Slight changes to the numerical results; Conclusion intact
Phys.Rev.D84:014007,2011
10.1103/PhysRevD.84.014007
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose to study the open charm effects in $e^+ e^-\to J/\psi\eta$, $J/\psi\pi^0$ and $\phi\eta_c$. We show that the exclusive cross section lineshapes of these processes would be strongly affected by the open charm effects. Since the final state light meson productions are through soft gluon radiations, we assume a recognition of this soft process via charmed meson loops at hadronic level. A unique feature among these three reactions is that the $D\bar{D^*}+c.c.$ open channel is located in a relatively isolated energy, i.e. $\sim 3.876$ GeV, which is sufficiently far away from the known charmonia $\psi(3770)$ and $\psi(4040)$. Therefore, the cross section lineshapes of these reactions may provide an opportunity for singling out the open charm effects with relatively well-defined charmonium contributions. In particular, we find that reaction $e^+ e^-\to J/\psi\pi^0$ is sensitive to the open charm $D\bar{D^*}+c.c.$ Due to the dominance of the isospin-0 component at the charmonium energy region, we predict an enhanced model-independent cusp effect between the thresholds of $D^0\bar{D}^0+c.c.$ and $D^+ D^{*-}+c.c.$ This study can also help us to understand the X(3900) enhancement recently observed by Belle Collaboration in $e^+ e^-\to D\bar{D}+c.c.$
[ { "created": "Sun, 6 Mar 2011 03:10:54 GMT", "version": "v1" }, { "created": "Mon, 20 Jun 2011 06:45:57 GMT", "version": "v2" } ]
2011-08-08
[ [ "Wang", "Qian", "" ], [ "Liu", "Xiao-Hai", "" ], [ "Zhao", "Qiang", "" ] ]
We propose to study the open charm effects in $e^+ e^-\to J/\psi\eta$, $J/\psi\pi^0$ and $\phi\eta_c$. We show that the exclusive cross section lineshapes of these processes would be strongly affected by the open charm effects. Since the final state light meson productions are through soft gluon radiations, we assume a recognition of this soft process via charmed meson loops at hadronic level. A unique feature among these three reactions is that the $D\bar{D^*}+c.c.$ open channel is located in a relatively isolated energy, i.e. $\sim 3.876$ GeV, which is sufficiently far away from the known charmonia $\psi(3770)$ and $\psi(4040)$. Therefore, the cross section lineshapes of these reactions may provide an opportunity for singling out the open charm effects with relatively well-defined charmonium contributions. In particular, we find that reaction $e^+ e^-\to J/\psi\pi^0$ is sensitive to the open charm $D\bar{D^*}+c.c.$ Due to the dominance of the isospin-0 component at the charmonium energy region, we predict an enhanced model-independent cusp effect between the thresholds of $D^0\bar{D}^0+c.c.$ and $D^+ D^{*-}+c.c.$ This study can also help us to understand the X(3900) enhancement recently observed by Belle Collaboration in $e^+ e^-\to D\bar{D}+c.c.$
0709.1996
Manmohan Gupta
Harleen Dahiya and Manmohan Gupta
$x-$dependence of the quark distribution functions in the $\chi$CQM$_{{\rm config}}$
20 pages, 7 figures. To appear in Eur. Phys. J. C
Eur.Phys.J.C52:571-579,2007
10.1140/epjc/s10052-007-0419-z
null
hep-ph
null
Chiral constituent quark model with configuration mixing (\chiCQM_{{\rm config}}) is known to provide a satisfactory explanation of the ``proton spin problem'' and related issues. In order to enlarge the scope of \chiCQM_{{\rm config}}, we have attempted to phenomenologically incorporate x-dependence in the quark distribution functions. In particular, apart from calculating valence and sea quark distributions q_{{\rm val}}(x) and \bar q(x), we have carried out a detailed analysis to estimate the sea quark asymmetries \bar d(x)-\bar u(x), \bar d(x)/\bar u(x) and \frac{\bar d(x)-\bar u(x)}{u(x)-d(x)} as well as spin independent structure functions F_2^p(x)-F_2^n(x) and $F_2^n(x)/F_2^p(x)$ as functions of $x$. We are able to achieve a satisfactory fit for all the above mentioned quantities simultaneously. The inclusion of effects due to configuration mixing have also been examined in the case F_2^p(x)-F_2^n(x) and F_2^n(x)/F_2^p(x) where the valence quark distributions dominate and it is found that it leads to considerable improvement in the results. Further, the valence quark structure has also be tested by extrapolating the predictions of our model in the limit x \to 1 where data is not available.
[ { "created": "Thu, 13 Sep 2007 06:45:11 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dahiya", "Harleen", "" ], [ "Gupta", "Manmohan", "" ] ]
Chiral constituent quark model with configuration mixing (\chiCQM_{{\rm config}}) is known to provide a satisfactory explanation of the ``proton spin problem'' and related issues. In order to enlarge the scope of \chiCQM_{{\rm config}}, we have attempted to phenomenologically incorporate x-dependence in the quark distribution functions. In particular, apart from calculating valence and sea quark distributions q_{{\rm val}}(x) and \bar q(x), we have carried out a detailed analysis to estimate the sea quark asymmetries \bar d(x)-\bar u(x), \bar d(x)/\bar u(x) and \frac{\bar d(x)-\bar u(x)}{u(x)-d(x)} as well as spin independent structure functions F_2^p(x)-F_2^n(x) and $F_2^n(x)/F_2^p(x)$ as functions of $x$. We are able to achieve a satisfactory fit for all the above mentioned quantities simultaneously. The inclusion of effects due to configuration mixing have also been examined in the case F_2^p(x)-F_2^n(x) and F_2^n(x)/F_2^p(x) where the valence quark distributions dominate and it is found that it leads to considerable improvement in the results. Further, the valence quark structure has also be tested by extrapolating the predictions of our model in the limit x \to 1 where data is not available.
hep-ph/9910390
Antonio Pich
A. Pich
Electroweak Precision Tests
11 pages, 9 figures. Invited talk at the International Workshop ``Particles in Astrophysics and Cosmology: from Theory to Observation'' (Valencia, 3-8 May 1999)
Nucl.Phys.Proc.Suppl.81:183-193,2000
10.1016/S0920-5632(99)00873-7
FTUV/99-69, IFIC/99-72
hep-ph
null
Precision measurements of electroweak observables provide stringent tests of the Standard Model structure and an accurate determination of its parameters. An overview of the present experimental status is presented.
[ { "created": "Mon, 18 Oct 1999 16:16:19 GMT", "version": "v1" } ]
2011-01-25
[ [ "Pich", "A.", "" ] ]
Precision measurements of electroweak observables provide stringent tests of the Standard Model structure and an accurate determination of its parameters. An overview of the present experimental status is presented.
hep-ph/9704312
Min Seok Baek
M.S. Baek, S.Y. Choi and C.S. Kim
CP Violation in the Top-Quark Pair Production at a Next Linear Collider
45 pages(LaTeX), 10 eps figures, uses epsfig.sty
Phys.Rev.D56:6835-6855,1997
10.1103/PhysRevD.56.6835
YUMS 97-7, SNUTP 97-035
hep-ph
null
We provide a detailed, model-independent, study for CP violation effects due to the T-odd top-quark electric dipole moment (EDM) and weak dipole moment (WDM) in the top-quark pair production via $e^+e^-$ and two-photon annihilation at a next $e^+e^-$ linear collider (NLC). There are two methods in detecting CP violation effects in these processes. One method makes use of measurements of various spin correlations in the final decay products of the produced top-quark pair, while the other is to measure various CP-odd polarization asymmetry effects of the initial states. In the $e^+e^-$ case only the first method can be used, and in the $\gamma\gamma$ case both methods can be employed. We provide a complete classification of angular correlations of the $t$ and $\bar{t}$ decay products under CP and CP\tilde{T} which greatly faciliate CP tests in the $e^+e^-$ mode. Concentrating on the second method with the Compton back-scattered high-energetic laser light off the electron or positron beam in the two-photon mode, we construct two CP-odd and CP\tilde{T}-even initial polarization configurations and apply them to investigating CP-violating effects due to the top-quark EDM. With a typical set of experimental parameters at the NLC, we compare the 1-\sigma sensitivities to the top-quark EDM and WDM in the $e^+e^-$ mode and the two-photon mode. Some model expectation values of the T-odd parameters are compared with the results.
[ { "created": "Mon, 14 Apr 1997 05:47:14 GMT", "version": "v1" } ]
2016-09-06
[ [ "Baek", "M. S.", "" ], [ "Choi", "S. Y.", "" ], [ "Kim", "C. S.", "" ] ]
We provide a detailed, model-independent, study for CP violation effects due to the T-odd top-quark electric dipole moment (EDM) and weak dipole moment (WDM) in the top-quark pair production via $e^+e^-$ and two-photon annihilation at a next $e^+e^-$ linear collider (NLC). There are two methods in detecting CP violation effects in these processes. One method makes use of measurements of various spin correlations in the final decay products of the produced top-quark pair, while the other is to measure various CP-odd polarization asymmetry effects of the initial states. In the $e^+e^-$ case only the first method can be used, and in the $\gamma\gamma$ case both methods can be employed. We provide a complete classification of angular correlations of the $t$ and $\bar{t}$ decay products under CP and CP\tilde{T} which greatly faciliate CP tests in the $e^+e^-$ mode. Concentrating on the second method with the Compton back-scattered high-energetic laser light off the electron or positron beam in the two-photon mode, we construct two CP-odd and CP\tilde{T}-even initial polarization configurations and apply them to investigating CP-violating effects due to the top-quark EDM. With a typical set of experimental parameters at the NLC, we compare the 1-\sigma sensitivities to the top-quark EDM and WDM in the $e^+e^-$ mode and the two-photon mode. Some model expectation values of the T-odd parameters are compared with the results.
1906.07659
Takashi Toma
Giorgio Arcadi, Oleg Lebedev, Stefan Pokorski, Takashi Toma
Real Scalar Dark Matter: Relativistic Treatment
27 pages, 10 figures, correction to the caption of fig.9
JHEP 08 (2019) 050
10.1007/JHEP08(2019)050
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A stable real scalar provides one of the simplest possibilities to account for dark matter. We consider the regime where its coupling to the Standard Model fields is negligibly small. Due to self-coupling, the scalar field can reach thermal or at least kinetic equilibrium, in which case the system is characterized by its temperature and effective chemical potential. We perform a fully relativistic analysis of dark matter evolution, thermalization conditions and different freeze-out regimes, including the chemical potential effects. To this end, we derive a relativistic Bose-Einstein analog of the Gelmini-Gondolo formula for a thermal averaged cross section. Finally, we perform a comprehensive parameter space analysis to determine regions consistent with observational constraints. Dark matter can be both warm and cold in this model.
[ { "created": "Tue, 18 Jun 2019 15:53:10 GMT", "version": "v1" }, { "created": "Thu, 20 Jun 2019 15:53:10 GMT", "version": "v2" } ]
2019-08-13
[ [ "Arcadi", "Giorgio", "" ], [ "Lebedev", "Oleg", "" ], [ "Pokorski", "Stefan", "" ], [ "Toma", "Takashi", "" ] ]
A stable real scalar provides one of the simplest possibilities to account for dark matter. We consider the regime where its coupling to the Standard Model fields is negligibly small. Due to self-coupling, the scalar field can reach thermal or at least kinetic equilibrium, in which case the system is characterized by its temperature and effective chemical potential. We perform a fully relativistic analysis of dark matter evolution, thermalization conditions and different freeze-out regimes, including the chemical potential effects. To this end, we derive a relativistic Bose-Einstein analog of the Gelmini-Gondolo formula for a thermal averaged cross section. Finally, we perform a comprehensive parameter space analysis to determine regions consistent with observational constraints. Dark matter can be both warm and cold in this model.
2207.02043
Zhi-Qing Zhang
Zhi-Qing Zhang, Yan-Chao Zhao, Zhi-Lin Guan, Zhi-Jie Sun, Zi-Yu Zhang, Ke-Yi He
Quasi-two-body decays $B_{(s)}\to K^*\gamma\to K\pi\gamma$ in perturbative QCD approach
10 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we study the quasi-two-body decays $B\to K^*\gamma\to K\pi\gamma$ in the perturbative QCD (PQCD) approach. The two-meson distribution amplitudes (DAs) are introduced to describe the final state interactions of the $K\pi$ pair, which involve the time-like form factors and the Gegenbauer polynomials. We calculate the CP averaged branching ratios for the decays $B_{(s)}\to K^*\gamma\to K\pi\gamma$. Our results are in agreement with the new update data measured by Belle II, which suggests these quasi-two-body decays are more appropriate to be analyzed in three-body framework than in the two-body one. We also predict the direct CP-violation asymmetries for the considered decay modes and find that $A_{CP}(B_{u,d}\to K^*\gamma\to K\pi\gamma)$ is small and less than $1\%$ in magnitude, while $A_{CP}(B_{s}\to K^*\gamma\to K\pi\gamma)$ is larger and can arrive at a few percent. Our predictions can be tested by the future B meson experiments.
[ { "created": "Tue, 5 Jul 2022 13:38:19 GMT", "version": "v1" } ]
2022-07-06
[ [ "Zhang", "Zhi-Qing", "" ], [ "Zhao", "Yan-Chao", "" ], [ "Guan", "Zhi-Lin", "" ], [ "Sun", "Zhi-Jie", "" ], [ "Zhang", "Zi-Yu", "" ], [ "He", "Ke-Yi", "" ] ]
In this work we study the quasi-two-body decays $B\to K^*\gamma\to K\pi\gamma$ in the perturbative QCD (PQCD) approach. The two-meson distribution amplitudes (DAs) are introduced to describe the final state interactions of the $K\pi$ pair, which involve the time-like form factors and the Gegenbauer polynomials. We calculate the CP averaged branching ratios for the decays $B_{(s)}\to K^*\gamma\to K\pi\gamma$. Our results are in agreement with the new update data measured by Belle II, which suggests these quasi-two-body decays are more appropriate to be analyzed in three-body framework than in the two-body one. We also predict the direct CP-violation asymmetries for the considered decay modes and find that $A_{CP}(B_{u,d}\to K^*\gamma\to K\pi\gamma)$ is small and less than $1\%$ in magnitude, while $A_{CP}(B_{s}\to K^*\gamma\to K\pi\gamma)$ is larger and can arrive at a few percent. Our predictions can be tested by the future B meson experiments.
1912.10625
Martin White Dr
Anna Mullin, Stuart Nicholls, Holly Pacey, Michael Parker, Martin White and Sarah Williams
Does SUSY have friends? A new approach for LHC event analysis
Version accepted by JHEP
Journal of High Energy Physics volume 2021, Article number: 160 (2021)
null
ADP-20-1/T1111
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel technique for the analysis of proton-proton collision events from the ATLAS and CMS experiments at the Large Hadron Collider. For a given final state and choice of kinematic variables, we build a graph network in which the individual events appear as weighted nodes, with edges between events defined by their distance in kinematic space. We then show that it is possible to calculate local metrics of the network that serve as event-by-event variables for separating signal and background processes, and we evaluate these for a number of different networks that are derived from different distance metrics. Using a supersymmetric electroweakino and stop production as examples, we construct prototype analyses that take account of the fact that the number of simulated Monte Carlo events used in an LHC analysis may differ from the number of events expected in the LHC dataset, allowing an accurate background estimate for a particle search at the LHC to be derived. For the electroweakino example, we show that the use of network variables outperforms both cut-and-count analyses that use the original variables and a boosted decision tree trained on the original variables. The stop example, deliberately chosen to be difficult to exclude due its kinematic similarity with the top background, demonstrates that network variables are not automatically sensitive to BSM physics. Nevertheless, we identify local network metrics that show promise if their robustness under certain assumptions of node-weighted networks can be confirmed.
[ { "created": "Mon, 23 Dec 2019 05:26:49 GMT", "version": "v1" }, { "created": "Wed, 22 Jan 2020 16:56:14 GMT", "version": "v2" }, { "created": "Wed, 24 Feb 2021 02:20:47 GMT", "version": "v3" } ]
2021-02-25
[ [ "Mullin", "Anna", "" ], [ "Nicholls", "Stuart", "" ], [ "Pacey", "Holly", "" ], [ "Parker", "Michael", "" ], [ "White", "Martin", "" ], [ "Williams", "Sarah", "" ] ]
We present a novel technique for the analysis of proton-proton collision events from the ATLAS and CMS experiments at the Large Hadron Collider. For a given final state and choice of kinematic variables, we build a graph network in which the individual events appear as weighted nodes, with edges between events defined by their distance in kinematic space. We then show that it is possible to calculate local metrics of the network that serve as event-by-event variables for separating signal and background processes, and we evaluate these for a number of different networks that are derived from different distance metrics. Using a supersymmetric electroweakino and stop production as examples, we construct prototype analyses that take account of the fact that the number of simulated Monte Carlo events used in an LHC analysis may differ from the number of events expected in the LHC dataset, allowing an accurate background estimate for a particle search at the LHC to be derived. For the electroweakino example, we show that the use of network variables outperforms both cut-and-count analyses that use the original variables and a boosted decision tree trained on the original variables. The stop example, deliberately chosen to be difficult to exclude due its kinematic similarity with the top background, demonstrates that network variables are not automatically sensitive to BSM physics. Nevertheless, we identify local network metrics that show promise if their robustness under certain assumptions of node-weighted networks can be confirmed.
1210.6141
Alka Upadhyay
Alka Upadhyay, Meenakshi Batra, Pallavi Gupta
Heavy-light charm mesons spectroscopy and decay widths
16 pages and 12 figures. arXiv admin note: text overlap with arXiv:hep-ph/0503134 by other authors
Prog. Theor. Exp. Phys. 2016 , 053B02
10.1093/ptep/ptw036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the mass formula for heavy-light charm meson for one loop, using heavy quark effective theory. Formulating an effective Lagrangian, the masses of the ground state heavy mesons have been studied in the heavy quark limit including leading corrections from finite heavy quark masses and nonzero light quark masses using a constrained fit for the eight equation having eleven parameters including three coupling constants g, h and g'. Masses determined from this approach is fitted to the experimentally known decay widths to estimate the strong coupling constants, showing a better match with available theoretical and experimental data
[ { "created": "Tue, 23 Oct 2012 06:49:17 GMT", "version": "v1" }, { "created": "Thu, 11 Feb 2016 10:50:49 GMT", "version": "v2" } ]
2016-06-27
[ [ "Upadhyay", "Alka", "" ], [ "Batra", "Meenakshi", "" ], [ "Gupta", "Pallavi", "" ] ]
We present the mass formula for heavy-light charm meson for one loop, using heavy quark effective theory. Formulating an effective Lagrangian, the masses of the ground state heavy mesons have been studied in the heavy quark limit including leading corrections from finite heavy quark masses and nonzero light quark masses using a constrained fit for the eight equation having eleven parameters including three coupling constants g, h and g'. Masses determined from this approach is fitted to the experimentally known decay widths to estimate the strong coupling constants, showing a better match with available theoretical and experimental data
hep-ph/9807291
Yuri Shtanov
O.V.Barabash (Shevchenko University, Kiev) and Yu.V.Shtanov (Bogolyubov Institute, Kiev)
Collapse of topological texture
23 pages, LaTeX, to be published in Phys. Rev. D
Phys.Rev. D58 (1998) 085015
10.1103/PhysRevD.58.085015
ITP-98-2E
hep-ph gr-qc
null
We study analytically the process of a topological texture collapse in the approximation of a scaling ansatz in the nonlinear sigma-model. In this approximation we show that in flat space-time topological texture eventually collapses while in the case of spatially flat expanding universe its fate depends on the rate of expansion. If the universe is inflationary, then there is a possibility that texture will expand eternally; in the case of exponential inflation the texture may also shrink or expand eternally to a finite limiting size, although this behavior is degenerate. In the case of power law noninflationary expansion topological texture eventually collapses. In a cold matter dominated universe we find that texture which is formed comoving with the universe expansion starts collapsing when its spatial size becomes comparable to the Hubble size, which result is in agreement with the previous considerations. In the nonlinear sigma-model approximation we consider also the final stage of the collapsing ellipsoidal topological texture. We show that during collapse of such a texture at least two of its principal dimensions shrink to zero in a similar way, so that their ratio remains finite. The third dimension may remain finite (collapse of cigar type), or it may also shrink to zero similar to the other two dimensions (collapse of scaling type), or shrink to zero similar to the product of the remaining two dimensions (collapse of pancake type).
[ { "created": "Wed, 8 Jul 1998 14:26:00 GMT", "version": "v1" } ]
2009-10-31
[ [ "Barabash", "O. V.", "", "Shevchenko University, Kiev" ], [ "Shtanov", "Yu. V.", "", "Bogolyubov Institute, Kiev" ] ]
We study analytically the process of a topological texture collapse in the approximation of a scaling ansatz in the nonlinear sigma-model. In this approximation we show that in flat space-time topological texture eventually collapses while in the case of spatially flat expanding universe its fate depends on the rate of expansion. If the universe is inflationary, then there is a possibility that texture will expand eternally; in the case of exponential inflation the texture may also shrink or expand eternally to a finite limiting size, although this behavior is degenerate. In the case of power law noninflationary expansion topological texture eventually collapses. In a cold matter dominated universe we find that texture which is formed comoving with the universe expansion starts collapsing when its spatial size becomes comparable to the Hubble size, which result is in agreement with the previous considerations. In the nonlinear sigma-model approximation we consider also the final stage of the collapsing ellipsoidal topological texture. We show that during collapse of such a texture at least two of its principal dimensions shrink to zero in a similar way, so that their ratio remains finite. The third dimension may remain finite (collapse of cigar type), or it may also shrink to zero similar to the other two dimensions (collapse of scaling type), or shrink to zero similar to the product of the remaining two dimensions (collapse of pancake type).
1403.7323
David H. Lyth
David H. Lyth
BICEP2, the curvature perturbation and supersymmetry
null
null
10.1088/1475-7516/2014/11/003
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The tensor fraction $r\simeq 0.16$ found by BICEP2 corresponds to a Hubble parameter $H\simeq 1.0\times 10^{14}\GeV$ during inflation. This has two implications for the (single-field) slow-roll inflation hypothesis. First, the inflaton perturbation must account for much more than $10\%$ of the curvature perturbation $\zeta$, which barring fine-tuning means that it accounts for practically all of it. It follows that a curvaton-like mechanism for generating $\zeta$ requires an alternative to slow roll such as k-inflation. Second, accepting slow-roll inflation, the excursion of the inflaton field is at least of order Planck scale. As a result, the flatness of the inflaton presumably requires a shift symmetry. I point out that if such is the case, the resulting potential is likely to have at least approximately the quadratic form suggested in 1983 by Linde, which is known to be compatible with the observed $r$ as well as the observed spectral index $\ns$. The shift symmetry does not require supersymmetry. Also, the big $H$ may rule out a GUT by restoring the symmetry and producing fatal cosmic strings. The absence of a GUT would correspond to the absence of superpartners for the Standard Model particles, which indeed have yet to be found at the LHC. It therefore seems quite possible that the quantum field theory chosen by Nature is not supersymmetric.
[ { "created": "Fri, 28 Mar 2014 10:03:43 GMT", "version": "v1" }, { "created": "Thu, 8 May 2014 14:36:52 GMT", "version": "v2" }, { "created": "Fri, 9 May 2014 14:12:30 GMT", "version": "v3" }, { "created": "Sun, 3 Aug 2014 08:13:39 GMT", "version": "v4" } ]
2015-06-19
[ [ "Lyth", "David H.", "" ] ]
The tensor fraction $r\simeq 0.16$ found by BICEP2 corresponds to a Hubble parameter $H\simeq 1.0\times 10^{14}\GeV$ during inflation. This has two implications for the (single-field) slow-roll inflation hypothesis. First, the inflaton perturbation must account for much more than $10\%$ of the curvature perturbation $\zeta$, which barring fine-tuning means that it accounts for practically all of it. It follows that a curvaton-like mechanism for generating $\zeta$ requires an alternative to slow roll such as k-inflation. Second, accepting slow-roll inflation, the excursion of the inflaton field is at least of order Planck scale. As a result, the flatness of the inflaton presumably requires a shift symmetry. I point out that if such is the case, the resulting potential is likely to have at least approximately the quadratic form suggested in 1983 by Linde, which is known to be compatible with the observed $r$ as well as the observed spectral index $\ns$. The shift symmetry does not require supersymmetry. Also, the big $H$ may rule out a GUT by restoring the symmetry and producing fatal cosmic strings. The absence of a GUT would correspond to the absence of superpartners for the Standard Model particles, which indeed have yet to be found at the LHC. It therefore seems quite possible that the quantum field theory chosen by Nature is not supersymmetric.
2006.04233
S Mohan Lakshmi Dr.
Lakshmi.S.Mohan
Probing the sensitivity to leptonic $\delta_{CP}$ in presence of invisible decay of $\nu_3$ using atmospheric neutrinos
updated reference list
null
10.1088/1361-6471/abacd9
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the main neutrino oscillation parameters whose value has not been determined very precisely is the leptonic $\delta_{CP}$ phase. Since neutrinos have a tiny but finite mass they can undergo decay both visibly and invisibly. The effect of invisible decay of the third mass eigen state $\nu_3$ on the sensitivity to $\delta_{CP}$ is analysed here using atmospheric neutrino and anti-neutrino events. Effects of detector resolutions and systematic uncertainties are studied to identify the optimum resolutions and efficiencies required by a detector to obtain a significant sensitivity even in presence of decay.
[ { "created": "Sun, 7 Jun 2020 18:55:29 GMT", "version": "v1" }, { "created": "Thu, 11 Jun 2020 12:35:07 GMT", "version": "v2" } ]
2020-10-28
[ [ "Mohan", "Lakshmi. S.", "" ] ]
One of the main neutrino oscillation parameters whose value has not been determined very precisely is the leptonic $\delta_{CP}$ phase. Since neutrinos have a tiny but finite mass they can undergo decay both visibly and invisibly. The effect of invisible decay of the third mass eigen state $\nu_3$ on the sensitivity to $\delta_{CP}$ is analysed here using atmospheric neutrino and anti-neutrino events. Effects of detector resolutions and systematic uncertainties are studied to identify the optimum resolutions and efficiencies required by a detector to obtain a significant sensitivity even in presence of decay.
hep-ph/9512345
null
B. Ananthanarayan and Q. Shafi
Radiative Electroweak Breaking with Pseudogoldstone Higgs Doublets
18 pages plain LaTeX (to be run twice) and 11 figures available separately from uuencoded files
Phys.Rev.D54:3488-3496,1996
10.1103/PhysRevD.54.3488
UNIL-TP-5/95, BA-95-17
hep-ph
null
We consider a realistic example of supersymmetric grand unification based on $SU(3)_c \times SU(3)_L \times SU(3)_R$ in which the electroweak (EW) higgs doublets are `light' as a consequence of the `pseudogoldstone' mechanism. We discuss radiative EW breaking in this model, exploring in particular the `small' (order unity) and `large' $(\approx m_t/m_b)$ $\tan \beta$ regions by studying the variations of $r (\equiv \sqrt{\mu^2_{1,2}/\mu^2_3})$, where $\mu^2_{1,2,3}$ are the well known MSSM parameters evaluated at the GUT scale. For $r$ sufficiently close to unity the quantity $\tan \beta$ can be of order unity, but the converse is not always true.
[ { "created": "Tue, 19 Dec 1995 09:23:08 GMT", "version": "v1" } ]
2011-05-12
[ [ "Ananthanarayan", "B.", "" ], [ "Shafi", "Q.", "" ] ]
We consider a realistic example of supersymmetric grand unification based on $SU(3)_c \times SU(3)_L \times SU(3)_R$ in which the electroweak (EW) higgs doublets are `light' as a consequence of the `pseudogoldstone' mechanism. We discuss radiative EW breaking in this model, exploring in particular the `small' (order unity) and `large' $(\approx m_t/m_b)$ $\tan \beta$ regions by studying the variations of $r (\equiv \sqrt{\mu^2_{1,2}/\mu^2_3})$, where $\mu^2_{1,2,3}$ are the well known MSSM parameters evaluated at the GUT scale. For $r$ sufficiently close to unity the quantity $\tan \beta$ can be of order unity, but the converse is not always true.
hep-ph/0101083
Michael Spira
M.M. M\"uhlleitner, M. Kr\"amer, M. Spira and P.M. Zerwas
Production of MSSM Higgs Bosons in Photon-Photon Collisions
9 pages, latex, 3 figures
Phys.Lett.B508:311-316,2001
10.1016/S0370-2693(01)00321-5
DESY 00-192, Edinburgh 2000/31, PM/00-45, PSI-PR-00-19
hep-ph
null
The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension of the Standard Model can be produced as single resonances at high-energy gamma gamma colliders. We have studied the prospects of the search for these particles in b\bar b and neutralino-pair final states. The Higgs bosons can be found with masses up to 70-80% of the initial e^\pm e^- collider energy for medium values of tan(beta), i.e. in areas of the supersymmetric parameter space not accessible at other colliders.
[ { "created": "Tue, 9 Jan 2001 17:14:28 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mühlleitner", "M. M.", "" ], [ "Krämer", "M.", "" ], [ "Spira", "M.", "" ], [ "Zerwas", "P. M.", "" ] ]
The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension of the Standard Model can be produced as single resonances at high-energy gamma gamma colliders. We have studied the prospects of the search for these particles in b\bar b and neutralino-pair final states. The Higgs bosons can be found with masses up to 70-80% of the initial e^\pm e^- collider energy for medium values of tan(beta), i.e. in areas of the supersymmetric parameter space not accessible at other colliders.
1306.6171
Vladimir Lomov
A.E. Kaloshin, E.A. Kobeleva, V.P. Lomov
Opposite parity fermion mixing and baryons $1/2^{\pm}$
11 pages, 8 figures
Mod. Phys. Lett. A, Vol. 28, No. 34 (2013) 1350156
10.1142/S0217732313501563
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a variant of $K$-matrix, which includes the effect of opposite parity fermions (OPF) mixing, and apply it for description of $\pi N$ partial waves $S_{11}$ and $P_{11}$. OPF-mixing leads to appearance of negative energy poles in $K$-matrix and restoration of MacDowell symmetry, relating two partial waves. Joint analysis of PWA results for $S_{11}$ and $P_{11}$ confirms significance of this effect.
[ { "created": "Wed, 26 Jun 2013 09:03:53 GMT", "version": "v1" } ]
2013-10-09
[ [ "Kaloshin", "A. E.", "" ], [ "Kobeleva", "E. A.", "" ], [ "Lomov", "V. P.", "" ] ]
We develop a variant of $K$-matrix, which includes the effect of opposite parity fermions (OPF) mixing, and apply it for description of $\pi N$ partial waves $S_{11}$ and $P_{11}$. OPF-mixing leads to appearance of negative energy poles in $K$-matrix and restoration of MacDowell symmetry, relating two partial waves. Joint analysis of PWA results for $S_{11}$ and $P_{11}$ confirms significance of this effect.
2210.14334
Daniel Pitonyak
Brandon Bauer, Daniel Pitonyak, and Cody Shay
Numerical study of the twist-3 asymmetry $A_{LT}$ in single-inclusive electron-nucleon and proton-proton collisions
21 pages, 14 figures, very minor changes, version to appear in PRD
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide the first rigorous numerical analysis of the longitudinal-transverse double-spin asymmetry $A_{LT}$ in electron-nucleon and proton-proton collisions for the case where only a single pion, jet, or photon is detected in the final state. Given recent extractions of certain, previously unknown, non-perturbative functions, we are able to compute contributions from all terms relevant for $A_{LT}$ and make realistic predictions for the observable at Jefferson Lab (JLab) 12 GeV, COMPASS, the future Electron-Ion Collider, and the Relativistic Heavy Ion Collider. We also compare our results to a JLab 6 GeV measurement, which are the only data available for this type of reaction. The twist-3 nature of $A_{LT}$ makes it a potentially fruitful avenue to probe quark-gluon-quark correlations in hadrons as well as provide insights into dynamical quark mass generation in QCD.
[ { "created": "Tue, 25 Oct 2022 21:01:54 GMT", "version": "v1" }, { "created": "Wed, 4 Jan 2023 14:46:00 GMT", "version": "v2" } ]
2023-01-05
[ [ "Bauer", "Brandon", "" ], [ "Pitonyak", "Daniel", "" ], [ "Shay", "Cody", "" ] ]
We provide the first rigorous numerical analysis of the longitudinal-transverse double-spin asymmetry $A_{LT}$ in electron-nucleon and proton-proton collisions for the case where only a single pion, jet, or photon is detected in the final state. Given recent extractions of certain, previously unknown, non-perturbative functions, we are able to compute contributions from all terms relevant for $A_{LT}$ and make realistic predictions for the observable at Jefferson Lab (JLab) 12 GeV, COMPASS, the future Electron-Ion Collider, and the Relativistic Heavy Ion Collider. We also compare our results to a JLab 6 GeV measurement, which are the only data available for this type of reaction. The twist-3 nature of $A_{LT}$ makes it a potentially fruitful avenue to probe quark-gluon-quark correlations in hadrons as well as provide insights into dynamical quark mass generation in QCD.
2104.06572
Xin Liu
Yutong Chen, Zewen Jiang, Xin Liu
Pure annihilation decays of $B_s^0 \to a_0^+ a_0^-$ and $B_d^0 \to K_0^{*+} K_0^{*-}$ in the PQCD approach
12 pages, 1 figure
Communications in Theoretical Physics 73 (2021) 045201
10.1088/1572-9494/abe0c1
JSNU-PHY-HEP-01/21
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the {\it CP}-averaged branching fractions and the {\it CP}-violating asymmetries in the pure annihilation decays of $B_s^0 \to a_0^+ a_0^-$ and $B_d^0 \to K_0^{*+} K_0^{*-}$, where $a_0\;[K_0^*]$ denotes the scalar $a_0(980)$ and $a_0(1450)$ [$K_0^*(800) ( {\rm or}\; \kappa)$ and $K_0^*(1430)$], with the perturbative QCD factorization approach under the assumption of two-quark structure for the $a_0$ and $K_0^*$ states. The numerical results show that the branching ratios of the $B_d^0 \to K_0^{*+} K_0^{*-}$ decays are in the order of $10^{-6}$, while the decay rates of the $B_s^0 \to a_0^+ a_0^-$ modes are in the order of $10^{-5}$. In light of the measured modes with the same quark components in the pseudoscalar sector, namely, $B_d^0 \to K^+ K^-$ and $B_s^0 \to \pi^+ \pi^-$, the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-II experiments in the (near) future. Meanwhile, it is of great interest to find that the twist-3 distribution amplitudes $\phi^{S}$ and $\phi^{T}$ with inclusion of the Gegenbauer polynomials for the scalar $a_0(1450)$ and $K_0^*(1430)$ states in scenario 2 contribute slightly to the branching ratios while significantly to the {\it CP} violations in the $B_d^0 \to {K_0^*}(1430)^+ {K_0^*}(1430)^-$ and $B_s^0 \to a_0(1450)^+ a_0(1450)^-$ decays, which indicates that, compared to the asymptotic $\phi^S$ and $\phi^T$, these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels. These predictions await for the future confirmation experimentally, which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.
[ { "created": "Wed, 14 Apr 2021 01:26:23 GMT", "version": "v1" } ]
2021-04-15
[ [ "Chen", "Yutong", "" ], [ "Jiang", "Zewen", "" ], [ "Liu", "Xin", "" ] ]
We study the {\it CP}-averaged branching fractions and the {\it CP}-violating asymmetries in the pure annihilation decays of $B_s^0 \to a_0^+ a_0^-$ and $B_d^0 \to K_0^{*+} K_0^{*-}$, where $a_0\;[K_0^*]$ denotes the scalar $a_0(980)$ and $a_0(1450)$ [$K_0^*(800) ( {\rm or}\; \kappa)$ and $K_0^*(1430)$], with the perturbative QCD factorization approach under the assumption of two-quark structure for the $a_0$ and $K_0^*$ states. The numerical results show that the branching ratios of the $B_d^0 \to K_0^{*+} K_0^{*-}$ decays are in the order of $10^{-6}$, while the decay rates of the $B_s^0 \to a_0^+ a_0^-$ modes are in the order of $10^{-5}$. In light of the measured modes with the same quark components in the pseudoscalar sector, namely, $B_d^0 \to K^+ K^-$ and $B_s^0 \to \pi^+ \pi^-$, the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-II experiments in the (near) future. Meanwhile, it is of great interest to find that the twist-3 distribution amplitudes $\phi^{S}$ and $\phi^{T}$ with inclusion of the Gegenbauer polynomials for the scalar $a_0(1450)$ and $K_0^*(1430)$ states in scenario 2 contribute slightly to the branching ratios while significantly to the {\it CP} violations in the $B_d^0 \to {K_0^*}(1430)^+ {K_0^*}(1430)^-$ and $B_s^0 \to a_0(1450)^+ a_0(1450)^-$ decays, which indicates that, compared to the asymptotic $\phi^S$ and $\phi^T$, these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels. These predictions await for the future confirmation experimentally, which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.
2301.05249
Pablo Escribano
Diego Portillo-S\'anchez, Pablo Escribano, Avelino Vicente
Ultraviolet extensions of the Scotogenic model
35 pages, 5 figures, 10 tables; v2: added new topology
null
null
IFIC/23-01
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Scotogenic model is a popular scenario that induces radiative Majorana neutrino masses and includes a weakly-interacting dark matter candidate. We classify all possible ultraviolet extensions of the Scotogenic model in which (i) the dark $\mathbb{Z}_2$ parity emerges at low energies after the spontaneous breaking of a global $\rm U(1)_L$ lepton number symmetry, and (ii) the low-energy effective theory contains a naturally small lepton number breaking parameter, suppressed by the mass of a heavy mediator integrated out at tree-level. We find $50$ such models and discuss two of them in detail to illustrate our setup. We also discuss some general aspects of the phenomenology of the models in our classification, exploring possible lepton flavor violating signals, collider signatures and implications for dark matter. The phenomenological prospects of these scenarios are very rich due to the presence of additional scalar states, including a massless Goldstone boson.
[ { "created": "Thu, 12 Jan 2023 19:01:43 GMT", "version": "v1" }, { "created": "Thu, 9 Mar 2023 12:46:07 GMT", "version": "v2" } ]
2023-03-10
[ [ "Portillo-Sánchez", "Diego", "" ], [ "Escribano", "Pablo", "" ], [ "Vicente", "Avelino", "" ] ]
The Scotogenic model is a popular scenario that induces radiative Majorana neutrino masses and includes a weakly-interacting dark matter candidate. We classify all possible ultraviolet extensions of the Scotogenic model in which (i) the dark $\mathbb{Z}_2$ parity emerges at low energies after the spontaneous breaking of a global $\rm U(1)_L$ lepton number symmetry, and (ii) the low-energy effective theory contains a naturally small lepton number breaking parameter, suppressed by the mass of a heavy mediator integrated out at tree-level. We find $50$ such models and discuss two of them in detail to illustrate our setup. We also discuss some general aspects of the phenomenology of the models in our classification, exploring possible lepton flavor violating signals, collider signatures and implications for dark matter. The phenomenological prospects of these scenarios are very rich due to the presence of additional scalar states, including a massless Goldstone boson.
hep-ph/0304300
Hoang Ngoc Long
D. V. Soa, T. Inami and H. N. Long
Bilepton production in electron-gamma collisions
11 pages, Latex, 6 figures, axodraw.sty used
Eur.Phys.J.C34:285-289,2004
10.1140/epjc/s2004-01725-5
null
hep-ph
null
We study the production of bileptons, new gauge boson of lepton number two, in the minimal 3 - 3 - 1 model in high energy electron - photon collisions. If the bilepton masses are in the range of 300 GeV the reaction will give observable cross-sections in the future colliders.
[ { "created": "Wed, 30 Apr 2003 17:41:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Soa", "D. V.", "" ], [ "Inami", "T.", "" ], [ "Long", "H. N.", "" ] ]
We study the production of bileptons, new gauge boson of lepton number two, in the minimal 3 - 3 - 1 model in high energy electron - photon collisions. If the bilepton masses are in the range of 300 GeV the reaction will give observable cross-sections in the future colliders.
hep-ph/0309263
Zuxiang Dai
Zuxiang Dai
Neutrino in Astrophysics and Cosmology
35 pages; paper also available at http://www.slac.stanford.edu/spires/find/hep/www?irn=5513251
null
null
null
hep-ph
null
At first we introduce the Neutrino in the standard Model, then the Dirac and Majorana Masses. After introducing the See-Saw Mechanism, we discuss the neutrino oscillations and the neutrino in astrophysics and cosmology. We finish this paper with a brief summary of the neutrino experiments.
[ { "created": "Tue, 23 Sep 2003 14:09:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dai", "Zuxiang", "" ] ]
At first we introduce the Neutrino in the standard Model, then the Dirac and Majorana Masses. After introducing the See-Saw Mechanism, we discuss the neutrino oscillations and the neutrino in astrophysics and cosmology. We finish this paper with a brief summary of the neutrino experiments.
2012.01960
Alessio Maiezza
Alessio Maiezza
Quark mixing with soft breaking of the parity in the minimal Left-Right model
18 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the possibility of soft breaking effects of the generalized parity within the minimal Left-Right model. One aim of the paper is to elaborate on the potentiality, the limit, and the predictivity of a restored parity at high scale. While revisiting the issue of strong CP in the Left-Right theories, we motivate the possibility of explicit-parity-breaking, that we then parameterize in the right-handed quark mixing matrix. The strong CP parameter $\bar{\theta}$ is also parameterized in terms of the breaking. We discuss some possible phenomenological consequences in this scenario. In particular, the constraint provided by $\bar{\theta}$ enables us to quantify the maximal deviation of the right-handed quark mixings from the standard case with exact parity in term of a single parameter. This deviation has a direct impact on flavor physics.
[ { "created": "Thu, 3 Dec 2020 14:35:22 GMT", "version": "v1" } ]
2020-12-04
[ [ "Maiezza", "Alessio", "" ] ]
We study the possibility of soft breaking effects of the generalized parity within the minimal Left-Right model. One aim of the paper is to elaborate on the potentiality, the limit, and the predictivity of a restored parity at high scale. While revisiting the issue of strong CP in the Left-Right theories, we motivate the possibility of explicit-parity-breaking, that we then parameterize in the right-handed quark mixing matrix. The strong CP parameter $\bar{\theta}$ is also parameterized in terms of the breaking. We discuss some possible phenomenological consequences in this scenario. In particular, the constraint provided by $\bar{\theta}$ enables us to quantify the maximal deviation of the right-handed quark mixings from the standard case with exact parity in term of a single parameter. This deviation has a direct impact on flavor physics.
1105.1672
Xiang Liu
Dian-Yong Chen, Jun He, Xue-Qian Li and Xiang Liu
Dipion invariant mass distribution of the anomalous $\Upsilon(1S) \pi^{+} \pi^{-}$ and $\Upsilon(2S) \pi^{+} \pi^{-}$ production near the peak of $\Upsilon(10860)$
5 pages, 4 figures, 3 tables. More references added and typos corrected. Matches version accepted for publication in PRD
Phys.Rev.D84:074006,2011
10.1103/PhysRevD.84.074006
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considering the defects of the previous work for estimating the anomalous production rates of $e^+e^-\to \Upsilon(1S)\pi^+\pi^-,\,\Upsilon(2S)\pi^+\pi^-$ near the peak of the $\Upsilon(5S)$ resonance at $\sqrt s=10.87$ GeV [K.F. Chen {\it et al}. (Belle Collaboration), Phys. Rev. Lett. {\bf 100}, 112001 (2008)], we suggest a new scenario where the contributions from the direct dipion transition and the final state interactions interfere to result in not only the anomalously large production rates, but also the lineshapes of the differential widths consistent with the experimental measurement when assuming the reactions are due to the dipion emission of $\Upsilon(5S)$. At the end, we raise a new puzzle that the predicted differential width $d\Gamma(\Upsilon(5S)\to\Upsilon(2S)\pi^+\pi^-)/d\cos\theta$ has a discrepant trend from the data while other predictions are well in accord with the data. It should be further clarified by more accurate measurements carried by future experiments.
[ { "created": "Mon, 9 May 2011 13:59:17 GMT", "version": "v1" }, { "created": "Thu, 26 May 2011 05:48:07 GMT", "version": "v2" }, { "created": "Thu, 25 Aug 2011 21:34:41 GMT", "version": "v3" }, { "created": "Wed, 14 Sep 2011 03:55:05 GMT", "version": "v4" } ]
2011-10-05
[ [ "Chen", "Dian-Yong", "" ], [ "He", "Jun", "" ], [ "Li", "Xue-Qian", "" ], [ "Liu", "Xiang", "" ] ]
Considering the defects of the previous work for estimating the anomalous production rates of $e^+e^-\to \Upsilon(1S)\pi^+\pi^-,\,\Upsilon(2S)\pi^+\pi^-$ near the peak of the $\Upsilon(5S)$ resonance at $\sqrt s=10.87$ GeV [K.F. Chen {\it et al}. (Belle Collaboration), Phys. Rev. Lett. {\bf 100}, 112001 (2008)], we suggest a new scenario where the contributions from the direct dipion transition and the final state interactions interfere to result in not only the anomalously large production rates, but also the lineshapes of the differential widths consistent with the experimental measurement when assuming the reactions are due to the dipion emission of $\Upsilon(5S)$. At the end, we raise a new puzzle that the predicted differential width $d\Gamma(\Upsilon(5S)\to\Upsilon(2S)\pi^+\pi^-)/d\cos\theta$ has a discrepant trend from the data while other predictions are well in accord with the data. It should be further clarified by more accurate measurements carried by future experiments.
0802.4430
Rouzbeh Allahverdi
Rouzbeh Allahverdi, Anupam Mazumdar
Affleck-Dine condensate, late thermalization and the gravitino problem
10 pages. Clarifying comments added, final version accepted for publication in Phys. Rev. D
Phys.Rev.D78:043511,2008
10.1103/PhysRevD.78.043511
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this clarifying note we discuss the late decay of an Affleck-Dine condensate by providing a no-go theorem that attributes to conserved global charges which are identified by the net particle number in fields which are included in the flat direction(s). For a rotating condensate, this implies that: (1) the net baryon/lepton number density stored in the condensate is always conserved, and (2) the total particle number density in the condensate cannot decrease. This reiterates that, irrespective of possible non-perturbative particle production due to $D$-terms in a multiple flat direction case, the prime decay mode of an Affleck-Dine condensate will be perturbative as originally envisaged. As a result, cosmological consequences of flat directions such as delayed thermalization as a novel solution to the gravitino overproduction problem will remain virtually intact.
[ { "created": "Fri, 29 Feb 2008 16:59:21 GMT", "version": "v1" }, { "created": "Tue, 24 Jun 2008 05:42:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Allahverdi", "Rouzbeh", "" ], [ "Mazumdar", "Anupam", "" ] ]
In this clarifying note we discuss the late decay of an Affleck-Dine condensate by providing a no-go theorem that attributes to conserved global charges which are identified by the net particle number in fields which are included in the flat direction(s). For a rotating condensate, this implies that: (1) the net baryon/lepton number density stored in the condensate is always conserved, and (2) the total particle number density in the condensate cannot decrease. This reiterates that, irrespective of possible non-perturbative particle production due to $D$-terms in a multiple flat direction case, the prime decay mode of an Affleck-Dine condensate will be perturbative as originally envisaged. As a result, cosmological consequences of flat directions such as delayed thermalization as a novel solution to the gravitino overproduction problem will remain virtually intact.
hep-ph/0209122
Rodolfo A. Diaz
Rodolfo A. Diaz, R. Martinez, and Nicanor Poveda
The process $\mu \to \nu_{e}e\bar{\nu}_{\mu} $in the 2HDM with flavor changing neutral currents
2 pages, no figures
Braz.J.Phys.33:831-833,2003
10.1590/S0103-97332003000400038
null
hep-ph
null
We consider the process $\mu \to \nu_{e}e\bar{\nu}_{\mu} $in the framework of a two Higgs doublet model with flavor changing neutral currents (FCNC). Since FCNC generates in turn flavor changing charged currents in the lepton sector, this process appears at tree level mediated by a charged Higgs boson exchange. From the experimental upper limit for this decay, we obtain the bound $| \xi_{\mu e}/m_{H^{\pm}}| \leq 3.8\times 10^{-3}$ where$ \xi_{\mu e} $refers to the mixing between the first and second lepton generations, and $m_{H^{\pm}} $denotes the mass of the charged Higgs boson. This bound is independent on the other free parameters of the model. In particular, for $m_{H^{\pm}}\simeq 100$GeV we get $| \xi_{e\mu}| $ $\lesssim 0.38$
[ { "created": "Wed, 11 Sep 2002 18:42:05 GMT", "version": "v1" } ]
2015-06-25
[ [ "Diaz", "Rodolfo A.", "" ], [ "Martinez", "R.", "" ], [ "Poveda", "Nicanor", "" ] ]
We consider the process $\mu \to \nu_{e}e\bar{\nu}_{\mu} $in the framework of a two Higgs doublet model with flavor changing neutral currents (FCNC). Since FCNC generates in turn flavor changing charged currents in the lepton sector, this process appears at tree level mediated by a charged Higgs boson exchange. From the experimental upper limit for this decay, we obtain the bound $| \xi_{\mu e}/m_{H^{\pm}}| \leq 3.8\times 10^{-3}$ where$ \xi_{\mu e} $refers to the mixing between the first and second lepton generations, and $m_{H^{\pm}} $denotes the mass of the charged Higgs boson. This bound is independent on the other free parameters of the model. In particular, for $m_{H^{\pm}}\simeq 100$GeV we get $| \xi_{e\mu}| $ $\lesssim 0.38$
hep-ph/0102170
Marco Battaglia
Marco Battaglia
Semileptonic B Decays - Recent Results from LEP and Comparison with Upsilon(4S) Data
15 pages, 6 figures, to apper in the Proceedings of the 5th Workshop on Heavy Quarks at Fixed Target, Rio de Janeiro, October 2000
null
null
null
hep-ph
null
Recent analyses of the LEP and Upsilon(4S) data have better outlined the picture of semileptonic B decays. Results on inclusive and exclusive decay branching fractions and on the extraction of the |Vub| and |Vcb| elements of the CKM mixing matrix are discussed, together with some of the still open questions and the sources of model systematics.
[ { "created": "Wed, 14 Feb 2001 13:39:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Battaglia", "Marco", "" ] ]
Recent analyses of the LEP and Upsilon(4S) data have better outlined the picture of semileptonic B decays. Results on inclusive and exclusive decay branching fractions and on the extraction of the |Vub| and |Vcb| elements of the CKM mixing matrix are discussed, together with some of the still open questions and the sources of model systematics.
0905.2772
Anosh Joseph
Anosh Joseph and S. G. Rajeev
Topological Dark Matter in the Little Higgs Models
4 pages, 1 figure; minor numerical error fixed
Phys.Rev.D80:074009,2009
10.1103/PhysRevD.80.074009
SU-4252-893
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that certain little Higgs models with symmetry breaking SU(N) -> SO(N) for N >= 4 admit topologically stable solitons that may contribute to cosmological dark matter. We have constructed a spherically symmetric soliton and estimated its mass in the case of SU(5) -> SO(5). Its lower bound is found to be around 10.3 TeV. Whether this particle is a fermion or a boson depends on the value of an integer-valued parameter of the underlying theory, analogous to the number of colors of QCD. In either case, the particle is neutral. If it is a fermion, it is a Majorana particle, which could take part in a seesaw mechanism for neutrino masses.
[ { "created": "Sun, 17 May 2009 21:53:01 GMT", "version": "v1" }, { "created": "Tue, 22 Sep 2009 20:31:53 GMT", "version": "v2" } ]
2009-11-06
[ [ "Joseph", "Anosh", "" ], [ "Rajeev", "S. G.", "" ] ]
We show that certain little Higgs models with symmetry breaking SU(N) -> SO(N) for N >= 4 admit topologically stable solitons that may contribute to cosmological dark matter. We have constructed a spherically symmetric soliton and estimated its mass in the case of SU(5) -> SO(5). Its lower bound is found to be around 10.3 TeV. Whether this particle is a fermion or a boson depends on the value of an integer-valued parameter of the underlying theory, analogous to the number of colors of QCD. In either case, the particle is neutral. If it is a fermion, it is a Majorana particle, which could take part in a seesaw mechanism for neutrino masses.
2110.13159
Jasmine Brewer
Jasmine Brewer, Quinn Brodsky, Krishna Rajagopal
Disentangling Jet Modification in Jet Simulations and in Z+Jet Data
16 pages, 8 figures
null
10.1007/JHEP02(2022)175
CERN-TH-2021-163, MIT-CTP/5344
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of selection biases on jet structure and substructure observables and separate these effects from effects caused by jet quenching. We use the angular separation $\Delta R$ of the hardest splitting in a jet as the primary example observable. We first conduct a simplified Monte Carlo study in which it is possible to identify the same jet after quenching in a heavy ion collision and as it would have been if it had formed in vacuum. We select a sample of jets by placing a cut on their quenched $p_T$ and, as is possible only in a Monte Carlo study, compare to the same jets unquenched, and see that the $\Delta R$ distribution seems to be unmodified. However, if we select a sample of jets formed in vacuum by placing a cut on their unquenched $p_T$ and compare to those same jets after quenching, we see a significant enhancement in the number of jets with large $\Delta R$, primarily due to the soft particles in the jet that originate from the wake in the droplet of quark-gluon plasma excited by the parton shower. We confirm that the jets contributing to this enhancement are those jets which lost the most energy, which were not included in the sample selected after quenching; jets selected after quenching are those which lose a small fraction of their energy. Next, we employ a method that is available to experimentalists: in a sample of jets with a recoiling $Z$ boson, we show that selecting jets based on the jet $p_T$ after quenching yields a $\Delta R$ distribution that appears unmodified while selecting a sample of jets produced in association with a $Z$ boson whose (unmodified) $p_T$ is above some cut yields a significant enhancement in the number of jets with large $\Delta R$. We again confirm that this is due to particles from the wake, and that the jets contributing to this enhancement are those which have lost a significant fraction of their energy.
[ { "created": "Mon, 25 Oct 2021 18:00:02 GMT", "version": "v1" } ]
2022-03-09
[ [ "Brewer", "Jasmine", "" ], [ "Brodsky", "Quinn", "" ], [ "Rajagopal", "Krishna", "" ] ]
We study the impact of selection biases on jet structure and substructure observables and separate these effects from effects caused by jet quenching. We use the angular separation $\Delta R$ of the hardest splitting in a jet as the primary example observable. We first conduct a simplified Monte Carlo study in which it is possible to identify the same jet after quenching in a heavy ion collision and as it would have been if it had formed in vacuum. We select a sample of jets by placing a cut on their quenched $p_T$ and, as is possible only in a Monte Carlo study, compare to the same jets unquenched, and see that the $\Delta R$ distribution seems to be unmodified. However, if we select a sample of jets formed in vacuum by placing a cut on their unquenched $p_T$ and compare to those same jets after quenching, we see a significant enhancement in the number of jets with large $\Delta R$, primarily due to the soft particles in the jet that originate from the wake in the droplet of quark-gluon plasma excited by the parton shower. We confirm that the jets contributing to this enhancement are those jets which lost the most energy, which were not included in the sample selected after quenching; jets selected after quenching are those which lose a small fraction of their energy. Next, we employ a method that is available to experimentalists: in a sample of jets with a recoiling $Z$ boson, we show that selecting jets based on the jet $p_T$ after quenching yields a $\Delta R$ distribution that appears unmodified while selecting a sample of jets produced in association with a $Z$ boson whose (unmodified) $p_T$ is above some cut yields a significant enhancement in the number of jets with large $\Delta R$. We again confirm that this is due to particles from the wake, and that the jets contributing to this enhancement are those which have lost a significant fraction of their energy.
1611.07334
Wei-Hong Liang
Wei-Hong Liang, Eulogio Oset, Zhu-Sheng Xie
Semileptonic $\Lambda_b \to \bar \nu_l l \Lambda_c(2595)$ and $\Lambda_b \to \bar \nu_l l \Lambda_c(2625)$ decays in the molecular picture of $\Lambda_c(2595)$ and $\Lambda_c(2625)$
7 pages, 3 figures
Phys. Rev. D 95, 014015 (2017)
10.1103/PhysRevD.95.014015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the partial decay widths for the semileptonic $\Lambda_b \to \bar \nu_l l \Lambda_c(2595)$ and $\Lambda_b \to \bar \nu_l l \Lambda_c(2625)$ decays from the perspective that these two $\Lambda^*_c$ resonances are dynamically generated from the $DN$ and $D^*N$ interaction with coupled channels. We find that the ratio of the rates obtained for these two reactions is compatible with present experimental data and is very sensitive to the $D^* N$ coupling, which becomes essential to obtain agreement with experiment. Together with the results obtained for the $\Lambda_b \to \pi^- \Lambda^*_c$ reactions, it gives strong support to the molecular picture of the two $\Lambda^*_c$ resonances and the important role of the $D^*N$ component neglected in prior studies of the $\Lambda_c(2595)$ from the molecular perspective.
[ { "created": "Tue, 22 Nov 2016 14:52:48 GMT", "version": "v1" } ]
2017-01-25
[ [ "Liang", "Wei-Hong", "" ], [ "Oset", "Eulogio", "" ], [ "Xie", "Zhu-Sheng", "" ] ]
We evaluate the partial decay widths for the semileptonic $\Lambda_b \to \bar \nu_l l \Lambda_c(2595)$ and $\Lambda_b \to \bar \nu_l l \Lambda_c(2625)$ decays from the perspective that these two $\Lambda^*_c$ resonances are dynamically generated from the $DN$ and $D^*N$ interaction with coupled channels. We find that the ratio of the rates obtained for these two reactions is compatible with present experimental data and is very sensitive to the $D^* N$ coupling, which becomes essential to obtain agreement with experiment. Together with the results obtained for the $\Lambda_b \to \pi^- \Lambda^*_c$ reactions, it gives strong support to the molecular picture of the two $\Lambda^*_c$ resonances and the important role of the $D^*N$ component neglected in prior studies of the $\Lambda_c(2595)$ from the molecular perspective.
hep-ph/9611307
null
Torben Hannah
Unitarity, Chiral Perturbation Theory, and Meson Form Factors
15 pages, 5 figs, uses REVTeX and epsfig.sty
Phys.Rev.D54:4648-4653,1996
10.1103/PhysRevD.54.4648
IFA-96/40
hep-ph
null
The inverse-amplitude method is applied to the one-loop chiral expansion of the pion, kaon, and $K_{l3}$ form factors. Since these form factors are determined by the same chiral low-energy constants, it is possible to obtain finite predictions for the inverse-amplitude method. It is shown that this method clearly improves one-loop chiral perturbation theory, and a very good agreement between the inverse-amplitude method and the experimental information is obtained. This suggests that the inverse-amplitude method is a rather systematic way of improving chiral perturbation theory.
[ { "created": "Tue, 12 Nov 1996 20:31:33 GMT", "version": "v1" } ]
2014-11-17
[ [ "Hannah", "Torben", "" ] ]
The inverse-amplitude method is applied to the one-loop chiral expansion of the pion, kaon, and $K_{l3}$ form factors. Since these form factors are determined by the same chiral low-energy constants, it is possible to obtain finite predictions for the inverse-amplitude method. It is shown that this method clearly improves one-loop chiral perturbation theory, and a very good agreement between the inverse-amplitude method and the experimental information is obtained. This suggests that the inverse-amplitude method is a rather systematic way of improving chiral perturbation theory.
1408.4605
Daniel Busbridge
Daniel Busbridge
Constrained Dirac gluino mediation
29 pages plus appendices, 31 figures, 5 tables, references added, typos corrected
null
null
IPPP/14/23, DCPT/14/46
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a comparison study of the Constrained Minimal Supersymmetric Standard Model and Constrained General Gauge Mediation with and without a heavy Dirac gluino. These extremely simple models have very few free parameters and exhibit the characteristic features of supersoftness and supersafeness. We determine the characteristic low energy spectra, the production cross sections of key processes at the Large Hadron Collider and the degree of fine tuning for a representative range of parameters for each model.
[ { "created": "Wed, 20 Aug 2014 11:00:55 GMT", "version": "v1" }, { "created": "Wed, 27 Aug 2014 12:09:34 GMT", "version": "v2" } ]
2014-08-28
[ [ "Busbridge", "Daniel", "" ] ]
We perform a comparison study of the Constrained Minimal Supersymmetric Standard Model and Constrained General Gauge Mediation with and without a heavy Dirac gluino. These extremely simple models have very few free parameters and exhibit the characteristic features of supersoftness and supersafeness. We determine the characteristic low energy spectra, the production cross sections of key processes at the Large Hadron Collider and the degree of fine tuning for a representative range of parameters for each model.