id
stringlengths
9
14
submitter
stringlengths
1
56
authors
stringlengths
5
7.68k
title
stringlengths
3
299
comments
stringlengths
1
1.15k
journal-ref
stringlengths
9
298
doi
stringlengths
12
97
report-no
stringlengths
3
341
categories
stringclasses
869 values
license
stringclasses
9 values
orig_abstract
stringlengths
16
2.44k
versions
listlengths
1
39
update_date
stringlengths
10
10
authors_parsed
listlengths
1
565
abstract
stringlengths
13
2.44k
hep-ph/0611052
Jisuke Kubo
Etsuko Itou, Yuji Kajiyama and Jisuke Kubo
The SUSY Flavor Problem, Proton Decay and Discrete Family Symmetry
5 pages, 1 figure, to appear in Proceedings of SUSY06, the 14th International Conference on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine, California, 12-17 June 2006
AIPConf.Proc.903:389-392,2007
10.1063/1.2735206
KANAZAWA-06-15
hep-ph
null
We consider a supersymmetric extension of the standard model, which possess a family symmetry based on a binary dihedral group Q6, and investigate the consequences of the family symmetry on the mixing of fermions, FCNCs and the stability of proton.
[ { "created": "Sat, 4 Nov 2006 13:06:33 GMT", "version": "v1" } ]
2008-11-26
[ [ "Itou", "Etsuko", "" ], [ "Kajiyama", "Yuji", "" ], [ "Kubo", "Jisuke", "" ] ]
We consider a supersymmetric extension of the standard model, which possess a family symmetry based on a binary dihedral group Q6, and investigate the consequences of the family symmetry on the mixing of fermions, FCNCs and the stability of proton.
2212.02218
Song Mao
Xiao-Hui Mei, Zhuo Yu, Mao Song, Jian-You Guo, Gang Li, Xuan Luo
Explanation of Y(4630) as hadronic resonant state
8 pages, 9 figures, accepted by Chinese Physics C
null
10.1088/1674-1137/aca959
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
After Y(4630) is discovered, theorists have given various explanations. We find that if Y(4630) is interpreted as the D-wave resonant state of $\Lambda_c \bar {\Lambda}_c$ system, the particle mass, decay width and all quantum numbers are consistent with experimental observations. We use the Bonn approximation to get the interaction potential of one boson exchange model, then extend the complex scaling method (CSM) to calculate the bound and resonant states. The results indicate that the $\Lambda_c \bar{\Lambda}_c$ system can form not only the bound state of S wave, but also the resonant state of the high angular momentum, and the $^3D_1$ wave resonant state can explain the structure of Y(4630) very well.
[ { "created": "Mon, 5 Dec 2022 12:50:21 GMT", "version": "v1" } ]
2023-02-22
[ [ "Mei", "Xiao-Hui", "" ], [ "Yu", "Zhuo", "" ], [ "Song", "Mao", "" ], [ "Guo", "Jian-You", "" ], [ "Li", "Gang", "" ], [ "Luo", "Xuan", "" ] ]
After Y(4630) is discovered, theorists have given various explanations. We find that if Y(4630) is interpreted as the D-wave resonant state of $\Lambda_c \bar {\Lambda}_c$ system, the particle mass, decay width and all quantum numbers are consistent with experimental observations. We use the Bonn approximation to get the interaction potential of one boson exchange model, then extend the complex scaling method (CSM) to calculate the bound and resonant states. The results indicate that the $\Lambda_c \bar{\Lambda}_c$ system can form not only the bound state of S wave, but also the resonant state of the high angular momentum, and the $^3D_1$ wave resonant state can explain the structure of Y(4630) very well.
hep-ph/9909306
Kenzo Ogure
K. Ogure and J. Sato
The Auxiliary Mass Method beyond the Local Potential Approximation
23 pages, 3 EPS figures
Prog.Theor.Phys. 106 (2001) 131-147
10.1143/PTP.106.131
UT-850
hep-ph
null
We show that the evolution equation of the effective potential in the auxiliary mass method corresponds to a leading approximation of a certain series. This series is derived from an evolution equation of an effective action using a derivative expansion. We derived an expression of the next-to-leading approximation of the evolution equation, which is a simultaneous partial differential equation.
[ { "created": "Thu, 9 Sep 1999 12:59:21 GMT", "version": "v1" }, { "created": "Tue, 14 Sep 1999 10:31:07 GMT", "version": "v2" } ]
2009-10-31
[ [ "Ogure", "K.", "" ], [ "Sato", "J.", "" ] ]
We show that the evolution equation of the effective potential in the auxiliary mass method corresponds to a leading approximation of a certain series. This series is derived from an evolution equation of an effective action using a derivative expansion. We derived an expression of the next-to-leading approximation of the evolution equation, which is a simultaneous partial differential equation.
hep-ph/0201138
Gottfried Holzwarth
G. Holzwarth (Siegen University)
Electromagnetic Form Factors of the Nucleon in the Chiral Soliton Model
8 pages, 5 figures
null
null
SI-TH-02-01
hep-ph
null
Several years ago it was pointed out that the chiral soliton model allows naturally for satisfactory agreement with the experimentally well-determined proton magnetic form factor $G_M^p$. The corresponding result for the proton electric form factor at that time was in serious disagreement with the data because the calculated $G_E^p$ showed as a rather stable feature a zero for $q^2$ near 10 (GeV/c)$^2$ which was hard to avoid for reasonable choices of parameters, while the data at that time showed no indication for such a behaviour. Meanwhile, new data have confirmed those $G_E^p$ predictions in a remarkable way, so it appears worthwhile to have another look at that model, especially concerning its flexibility with repect to the electric neutron formfactor $G_E^n$ while trying to maintain the satisfactory results for the proton form factors.
[ { "created": "Tue, 15 Jan 2002 14:48:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Holzwarth", "G.", "", "Siegen University" ] ]
Several years ago it was pointed out that the chiral soliton model allows naturally for satisfactory agreement with the experimentally well-determined proton magnetic form factor $G_M^p$. The corresponding result for the proton electric form factor at that time was in serious disagreement with the data because the calculated $G_E^p$ showed as a rather stable feature a zero for $q^2$ near 10 (GeV/c)$^2$ which was hard to avoid for reasonable choices of parameters, while the data at that time showed no indication for such a behaviour. Meanwhile, new data have confirmed those $G_E^p$ predictions in a remarkable way, so it appears worthwhile to have another look at that model, especially concerning its flexibility with repect to the electric neutron formfactor $G_E^n$ while trying to maintain the satisfactory results for the proton form factors.
hep-ph/0510029
Thomas Kernreiter
A. Bartl, H. Fraas, S. Hesselbach, K. Hohenwarter-Sodek, T. Kernreiter, G. Moortgat-Pick
CP-odd observables in neutralino production with transverse e+ and e- beam polarization
30 pages, minor changes in the introduction, references added
JHEP 0601 (2006) 170
10.1088/1126-6708/2006/01/170
null
hep-ph
null
We consider neutralino production and decay e^+e^ --> chi^0_i chi^0_j, chi^0_j --> chi^0_1 f \bar{f} at a linear collider with transverse e^+ and e^- beam polarization. We propose CP asymmetries by means of the azimuthal distribution of the produced neutralinos and of that of the final leptons, while taking also into account the subsequent decays of the neutralinos. We include the complete spin correlations between production and decay. Our framework is the Minimal Supersymmetric Standard Model with complex parameters. In a numerical study we show that there are good prospects to observe these CP asymmetries at the International Linear Collider and estimate the accuracy expected for the determination of the phases in the neutralino sector.
[ { "created": "Mon, 3 Oct 2005 16:34:02 GMT", "version": "v1" }, { "created": "Thu, 22 Dec 2005 11:44:30 GMT", "version": "v2" } ]
2009-11-11
[ [ "Bartl", "A.", "" ], [ "Fraas", "H.", "" ], [ "Hesselbach", "S.", "" ], [ "Hohenwarter-Sodek", "K.", "" ], [ "Kernreiter", "T.", "" ], [ "Moortgat-Pick", "G.", "" ] ]
We consider neutralino production and decay e^+e^ --> chi^0_i chi^0_j, chi^0_j --> chi^0_1 f \bar{f} at a linear collider with transverse e^+ and e^- beam polarization. We propose CP asymmetries by means of the azimuthal distribution of the produced neutralinos and of that of the final leptons, while taking also into account the subsequent decays of the neutralinos. We include the complete spin correlations between production and decay. Our framework is the Minimal Supersymmetric Standard Model with complex parameters. In a numerical study we show that there are good prospects to observe these CP asymmetries at the International Linear Collider and estimate the accuracy expected for the determination of the phases in the neutralino sector.
1212.0904
Gilberto Tavares-Velasco
A. Bola\~nos, A. Fernandez, A. Moyotl, and G. Tavares-Velasco
Analysis of mu-tau conversion through \mu N -> \tau X deep inelastic scattering induced by unparticles
13 pages, 8 figures, 1 table, minor corrections to match published version
Phys.Rev. D87 (2013) 016004
10.1103/PhysRevD.87.016004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A study of mu-tau conversion via the deep inelastic scattering process \mu N -> \tau X, with N a nucleon, is performed taking into account the effects from both spin-0 and spin-1 unparticles with lepton flavor violating (LFV) couplings. This process has attracted attention in the past as it may be at the reach of a future neutrino or muon factory. For the model parameters, we use the most recent constraints on the unparticle LFV couplings from the experimental limits on the muon anomalous magnetic moment and the LFV decay \tau-> 3\mu, whereas for the unparticle scale \Lambda_U and scale dimension d_U we use the bounds obtained from the search for mono-jets plus missing transverse energy at the LHC. The \mu N -> \tau X cross section is analyzed when the target is a proton and it is found that the unparticle effects can be larger than the contribution from Higgs exchange in the minimal supersymmetric standard model. We also analyze the behavior of the angular and energy distributions of the emitted tau lepton, which could be used to disentangle among distinct new physics contributions. It is found that, for a beam with an intensity of 10^20 muons with an energy around 50 GeV on a 10^2 gr/cm^2 mass target annually, there would be about 10^2-10^3 \mu N -> \tau X events per year. The potential background is discussed briefly.
[ { "created": "Tue, 4 Dec 2012 23:43:01 GMT", "version": "v1" }, { "created": "Thu, 20 Dec 2012 06:12:59 GMT", "version": "v2" } ]
2013-01-07
[ [ "Bolaños", "A.", "" ], [ "Fernandez", "A.", "" ], [ "Moyotl", "A.", "" ], [ "Tavares-Velasco", "G.", "" ] ]
A study of mu-tau conversion via the deep inelastic scattering process \mu N -> \tau X, with N a nucleon, is performed taking into account the effects from both spin-0 and spin-1 unparticles with lepton flavor violating (LFV) couplings. This process has attracted attention in the past as it may be at the reach of a future neutrino or muon factory. For the model parameters, we use the most recent constraints on the unparticle LFV couplings from the experimental limits on the muon anomalous magnetic moment and the LFV decay \tau-> 3\mu, whereas for the unparticle scale \Lambda_U and scale dimension d_U we use the bounds obtained from the search for mono-jets plus missing transverse energy at the LHC. The \mu N -> \tau X cross section is analyzed when the target is a proton and it is found that the unparticle effects can be larger than the contribution from Higgs exchange in the minimal supersymmetric standard model. We also analyze the behavior of the angular and energy distributions of the emitted tau lepton, which could be used to disentangle among distinct new physics contributions. It is found that, for a beam with an intensity of 10^20 muons with an energy around 50 GeV on a 10^2 gr/cm^2 mass target annually, there would be about 10^2-10^3 \mu N -> \tau X events per year. The potential background is discussed briefly.
1303.1356
Ben King
B. King, H. Ruhl
Trident pair production in a constant crossed field
16 pages, 12 figures. Updated with published version
null
10.1103/PhysRevD.88.013005
null
hep-ph hep-th physics.plasm-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We isolate the two-step mechanism involving a real intermediate photon from the one-step mechanism involving a virtual photon for the trident process in a constant crossed field. The two-step process is shown to agree with an integration over polarised sub-processes. At low to moderate quantum non-linearity parameter, the one-step process is found to be suppressed. When the parameter is large, the two decay channels are comparable if the field dimensions are not much greater than the formation length.
[ { "created": "Wed, 6 Mar 2013 15:38:07 GMT", "version": "v1" }, { "created": "Mon, 29 Apr 2013 14:30:38 GMT", "version": "v2" }, { "created": "Tue, 2 Jul 2013 09:14:02 GMT", "version": "v3" } ]
2013-07-11
[ [ "King", "B.", "" ], [ "Ruhl", "H.", "" ] ]
We isolate the two-step mechanism involving a real intermediate photon from the one-step mechanism involving a virtual photon for the trident process in a constant crossed field. The two-step process is shown to agree with an integration over polarised sub-processes. At low to moderate quantum non-linearity parameter, the one-step process is found to be suppressed. When the parameter is large, the two decay channels are comparable if the field dimensions are not much greater than the formation length.
1508.07051
Mehmet Guclu C
M. Y. Sengul, M. C. Guclu, O. Mercan, and N. G. Karakus
Electromagnetic Heavy Lepton Pair Production in Relativistic Heavy-Ion Collisions
14 pages, 33 figures
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the cross sections of electromagnetic productions of muon and tauon pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement [1] indicates that the neutrons are differently distributed from the protons therefore this affects the cross section of the heavy lepton pair production. In order to see the effects of the neutron distributions in the nucleus, we used analytical expression of the Fourier transforms of the Wood-Saxon distribution. Cross section calculations show that Wood-Saxon distribution function is more sensitive to the parameter R compare to the parameter a.
[ { "created": "Thu, 27 Aug 2015 22:48:17 GMT", "version": "v1" } ]
2015-08-31
[ [ "Sengul", "M. Y.", "" ], [ "Guclu", "M. C.", "" ], [ "Mercan", "O.", "" ], [ "Karakus", "N. G.", "" ] ]
We calculate the cross sections of electromagnetic productions of muon and tauon pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement [1] indicates that the neutrons are differently distributed from the protons therefore this affects the cross section of the heavy lepton pair production. In order to see the effects of the neutron distributions in the nucleus, we used analytical expression of the Fourier transforms of the Wood-Saxon distribution. Cross section calculations show that Wood-Saxon distribution function is more sensitive to the parameter R compare to the parameter a.
0704.0928
Luis Anchordoqui
Luis Anchordoqui, Haim Goldberg, Satoshi Nawata, Carlos Nunez
Cosmology from String Theory
Version to be published in Physical Review D
Phys.Rev.D76:126005,2007
10.1103/PhysRevD.76.126005
null
hep-ph astro-ph hep-th
null
We explore the cosmological content of Salam-Sezgin six dimensional supergravity, and find a solution to the field equations in qualitative agreement with observation of distant supernovae, primordial nucleosynthesis abundances, and recent measurements of the cosmic microwave background. The carrier of the acceleration in the present de Sitter epoch is a quintessence field slowly rolling down its exponential potential. Intrinsic to this model is a second modulus which is automatically stabilized and acts as a source of cold dark matter with a mass proportional to an exponential function of the quintessence field (hence realizing VAMP models within a String context). However, any attempt to saturate the present cold dark matter component in this manner leads to unacceptable deviations from cosmological data -- a numerical study reveals that this source can account for up to about 7% of the total cold dark matter budget. We also show that (1) the model will support a de Sitter energy in agreement with observation at the expense of a miniscule breaking of supersymmetry in the compact space; (2) variations in the fine structure constant are controlled by the stabilized modulus and are negligible; (3) ``fifth''forces are carried by the stabilized modulus and are short range; (4) the long time behavior of the model in four dimensions is that of a Robertson-Walker universe with a constant expansion rate (w = -1/3). Finally, we present a String theory background by lifting our six dimensional cosmological solution to ten dimensions.
[ { "created": "Fri, 6 Apr 2007 20:00:10 GMT", "version": "v1" }, { "created": "Wed, 2 May 2007 19:29:10 GMT", "version": "v2" }, { "created": "Fri, 26 Oct 2007 11:18:37 GMT", "version": "v3" } ]
2008-11-26
[ [ "Anchordoqui", "Luis", "" ], [ "Goldberg", "Haim", "" ], [ "Nawata", "Satoshi", "" ], [ "Nunez", "Carlos", "" ] ]
We explore the cosmological content of Salam-Sezgin six dimensional supergravity, and find a solution to the field equations in qualitative agreement with observation of distant supernovae, primordial nucleosynthesis abundances, and recent measurements of the cosmic microwave background. The carrier of the acceleration in the present de Sitter epoch is a quintessence field slowly rolling down its exponential potential. Intrinsic to this model is a second modulus which is automatically stabilized and acts as a source of cold dark matter with a mass proportional to an exponential function of the quintessence field (hence realizing VAMP models within a String context). However, any attempt to saturate the present cold dark matter component in this manner leads to unacceptable deviations from cosmological data -- a numerical study reveals that this source can account for up to about 7% of the total cold dark matter budget. We also show that (1) the model will support a de Sitter energy in agreement with observation at the expense of a miniscule breaking of supersymmetry in the compact space; (2) variations in the fine structure constant are controlled by the stabilized modulus and are negligible; (3) ``fifth''forces are carried by the stabilized modulus and are short range; (4) the long time behavior of the model in four dimensions is that of a Robertson-Walker universe with a constant expansion rate (w = -1/3). Finally, we present a String theory background by lifting our six dimensional cosmological solution to ten dimensions.
1506.01705
Gino Isidori
Admir Greljo, Gino Isidori, David Marzocca
On the breaking of Lepton Flavor Universality in B decays
20 pages, 7 figures. v2: discussion on flavor structure clarified; added discussion on the associated production of the heavy vectors and a few refs. Published version
null
null
ZU-TH-16/15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In view of recent experimental indications of violations of Lepton Flavor Universality (LFU) in $B$ decays, we analyze constraints and implications of LFU interactions, both using an effective theory approach, and an explicit dynamical model. We show that a simple dynamical model based on a $SU(2)_L$ triplet of massive vector bosons, coupled predominantly to third generation fermions (both quarks and leptons), can significantly improve the description of present data. In particular, the model decreases the tension between data and SM predictions concerning: i) the breaking of $\tau$-$\mu$ universality in $B\to D^{(*)} \ell \nu$ decays; ii) the breaking of $\mu$-$e$ universality in $B \to K \ell^+\ell^-$ decays; iii) the difference between exclusive and inclusive determinations of $|V_{cb}|$ and $|V_{ub}|$. The minimal version of the model is in tension with ATLAS and CMS direct searches for the new massive vectors (decaying into $\tau^+\tau^-$ pairs), but this tension can be decreased with additional non-standard degrees of freedom. Further predictions of the model both at low- and high-energies, in view of future high-statistics data, are discussed.
[ { "created": "Thu, 4 Jun 2015 19:56:22 GMT", "version": "v1" }, { "created": "Thu, 2 Jul 2015 07:48:39 GMT", "version": "v2" } ]
2015-07-03
[ [ "Greljo", "Admir", "" ], [ "Isidori", "Gino", "" ], [ "Marzocca", "David", "" ] ]
In view of recent experimental indications of violations of Lepton Flavor Universality (LFU) in $B$ decays, we analyze constraints and implications of LFU interactions, both using an effective theory approach, and an explicit dynamical model. We show that a simple dynamical model based on a $SU(2)_L$ triplet of massive vector bosons, coupled predominantly to third generation fermions (both quarks and leptons), can significantly improve the description of present data. In particular, the model decreases the tension between data and SM predictions concerning: i) the breaking of $\tau$-$\mu$ universality in $B\to D^{(*)} \ell \nu$ decays; ii) the breaking of $\mu$-$e$ universality in $B \to K \ell^+\ell^-$ decays; iii) the difference between exclusive and inclusive determinations of $|V_{cb}|$ and $|V_{ub}|$. The minimal version of the model is in tension with ATLAS and CMS direct searches for the new massive vectors (decaying into $\tau^+\tau^-$ pairs), but this tension can be decreased with additional non-standard degrees of freedom. Further predictions of the model both at low- and high-energies, in view of future high-statistics data, are discussed.
2305.16431
Natsumi Ikeno
Natsumi Ikeno, Genaro Toledo, Eulogio Oset
Model independent analysis of femtoscopic correlation functions: An application to the $D_{s0}^*(2317)$
8 pages, 2 figures, 2 tables: numerical results are updated and table II is added
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We face the inverse problem of obtaining the interaction between coupled channels from the correlation functions of these channels. We apply the method to the interaction of the $D^0 K^+$, $D^+ K^0$, and $D^+_s \eta$ channels, from where the $D^*_{s0}(2317)$ state emerges. We use synthetic data extracted from an interaction model based on the local hidden gauge approach and find that the inverse problem can determine the existence of a bound state of the system with a precision of about 20 MeV. At the same time, we can determine the isospin nature of the bound state and its compositeness in terms of the channels. Furthermore, we evaluate the scattering length and effective range of all three channels, as well as the couplings of the bound state found to all the components. Lastly, the size parameter of the source function, $R$, which in principle should be a magnitude provided by the experimental teams, can be obtained from a fit to the data with relatively high accuracy. These findings show the value of the correlation function to learn about the meson-meson interaction for systems which are difficult to access in other present facilities.
[ { "created": "Thu, 25 May 2023 19:11:50 GMT", "version": "v1" }, { "created": "Wed, 12 Jul 2023 17:12:29 GMT", "version": "v2" } ]
2023-07-13
[ [ "Ikeno", "Natsumi", "" ], [ "Toledo", "Genaro", "" ], [ "Oset", "Eulogio", "" ] ]
We face the inverse problem of obtaining the interaction between coupled channels from the correlation functions of these channels. We apply the method to the interaction of the $D^0 K^+$, $D^+ K^0$, and $D^+_s \eta$ channels, from where the $D^*_{s0}(2317)$ state emerges. We use synthetic data extracted from an interaction model based on the local hidden gauge approach and find that the inverse problem can determine the existence of a bound state of the system with a precision of about 20 MeV. At the same time, we can determine the isospin nature of the bound state and its compositeness in terms of the channels. Furthermore, we evaluate the scattering length and effective range of all three channels, as well as the couplings of the bound state found to all the components. Lastly, the size parameter of the source function, $R$, which in principle should be a magnitude provided by the experimental teams, can be obtained from a fit to the data with relatively high accuracy. These findings show the value of the correlation function to learn about the meson-meson interaction for systems which are difficult to access in other present facilities.
hep-ph/9602402
Paolo Gondolo
P. Gondolo (Oxford), G. Ingelman, M. Thunman (Uppsala)
Atmospheric muons and neutrinos from charm
Talk presented by P. Gondolo at TAUP95, Toledo, Sept. 1995. 3 pages, 2 Postscript figures, uses epsf.sty and espcrc2.sty
Nucl.Phys.Proc.Suppl. 48 (1996) 472-474
10.1016/0920-5632(96)00294-0
null
hep-ph
null
We have updated our previous investigation of the production of muons and neutrinos in cosmic ray interactions with the atmosphere, taking account of recent results from the $ep$ collider HERA in our QCD-based model for hadronic interactions. Qualitatively, our previous results remain unmodified: our predictions for the conventional muon and neutrino fluxes agree with earlier calculations, whereas the charm particle treatment we use gives significantly lower prompt fluxes compared to earlier estimates. This implies better prospects for detecting very high energy neutrinos from cosmic sources.
[ { "created": "Mon, 26 Feb 1996 21:28:22 GMT", "version": "v1" } ]
2009-10-28
[ [ "Gondolo", "P.", "", "Oxford" ], [ "Ingelman", "G.", "", "Uppsala" ], [ "Thunman", "M.", "", "Uppsala" ] ]
We have updated our previous investigation of the production of muons and neutrinos in cosmic ray interactions with the atmosphere, taking account of recent results from the $ep$ collider HERA in our QCD-based model for hadronic interactions. Qualitatively, our previous results remain unmodified: our predictions for the conventional muon and neutrino fluxes agree with earlier calculations, whereas the charm particle treatment we use gives significantly lower prompt fluxes compared to earlier estimates. This implies better prospects for detecting very high energy neutrinos from cosmic sources.
1704.07341
Frank E. Taylor
Frank E. Taylor
Radial Scaling in Inclusive Jet Production at Hadron Colliders
47 pages, 22 figures, 6 tables. Version 2 - more data added, references enhanced
Phys. Rev. D 97, 054016 (2018)
10.1103/PhysRevD.97.054016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inclusive jet production in p-p and pbar-p collisions shows many of the same kinematic systematics as observed in single particle inclusive production at much lower energies. In an earlier study (1974) a phenomenology, called radial scaling, was developed for the single particle inclusive cross sections that attempted to capture the essential underlying physics of point-like parton scattering and the fragmentation of partons into hadrons suppressed by the kinematic boundary. The phenomenology was successful in emphasizing the underlying systematics of the inclusive particle productions. Here we demonstrate that inclusive jet production at the LHC in high-energy p-p collisions and at the Tevatron in pbar-p inelastic scattering show similar behavior. The ATLAS inclusive jet production plotted as a function of this scaling variable is studied for sqrt(s) of 2.76, 7 and 13 TeV and is compared to pbar-p inclusive jet production at 1.96 TeV measured at the CDF and D0 at the Tevatron and p-Pb inclusive jet production at the LHC ATLAS at sqrt(sNN) = 5.02 TeV. Inclusive single particle production at FNAL fixed target and ISR energies are compared to inclusive J/Psi production at the LHC measured in ATLAS, CMS and LHCb. Striking common features of the data are discussed.
[ { "created": "Mon, 24 Apr 2017 17:26:50 GMT", "version": "v1" }, { "created": "Mon, 29 Jan 2018 16:25:34 GMT", "version": "v2" } ]
2018-03-21
[ [ "Taylor", "Frank E.", "" ] ]
Inclusive jet production in p-p and pbar-p collisions shows many of the same kinematic systematics as observed in single particle inclusive production at much lower energies. In an earlier study (1974) a phenomenology, called radial scaling, was developed for the single particle inclusive cross sections that attempted to capture the essential underlying physics of point-like parton scattering and the fragmentation of partons into hadrons suppressed by the kinematic boundary. The phenomenology was successful in emphasizing the underlying systematics of the inclusive particle productions. Here we demonstrate that inclusive jet production at the LHC in high-energy p-p collisions and at the Tevatron in pbar-p inelastic scattering show similar behavior. The ATLAS inclusive jet production plotted as a function of this scaling variable is studied for sqrt(s) of 2.76, 7 and 13 TeV and is compared to pbar-p inclusive jet production at 1.96 TeV measured at the CDF and D0 at the Tevatron and p-Pb inclusive jet production at the LHC ATLAS at sqrt(sNN) = 5.02 TeV. Inclusive single particle production at FNAL fixed target and ISR energies are compared to inclusive J/Psi production at the LHC measured in ATLAS, CMS and LHCb. Striking common features of the data are discussed.
hep-ph/0405156
Jose Enrique Garcia
J. E. Garcia (for the ATLAS Collaboration)
Little Higgs searches at LHC
8 pages, 8 figures, XXXIXth Rencontres de Moriond, La Thuile(2004)
null
null
null
hep-ph
null
A new method of solving the hierarchy problem in the SM has been proposed. This method leads to the so-called "Little Higgs" models. The ATLAS experiment at LHC has undertaken studies of the new particles predicted by these model: a heavy top quark, heavy gauge bosons and additional Higgs bosons. Simulations of their decays have been carried out. The sensitivity of the ATLAS experiment to discover these new particles is discussed.
[ { "created": "Mon, 17 May 2004 16:03:15 GMT", "version": "v1" } ]
2019-08-14
[ [ "Garcia", "J. E.", "", "for the ATLAS Collaboration" ] ]
A new method of solving the hierarchy problem in the SM has been proposed. This method leads to the so-called "Little Higgs" models. The ATLAS experiment at LHC has undertaken studies of the new particles predicted by these model: a heavy top quark, heavy gauge bosons and additional Higgs bosons. Simulations of their decays have been carried out. The sensitivity of the ATLAS experiment to discover these new particles is discussed.
hep-ph/0411347
Christian Fischer
C. S. Fischer and R. Alkofer
Dynamical Chiral Symmetry Breaking in Landau gauge QCD
4 pages, 2 figures, talk given by C.F. at 6th Conference on Quark Confinement and the Hadron Spectrum, Villasimius, Sardinia, Italy, 21-25 Sep 2004
AIPConf.Proc.756:275-277,2005
10.1063/1.1920965
UNITU-THEP-16/2004, IPPP/04/75, DCPT/04/150
hep-ph
null
We summarise results for the propagators of Landau gauge QCD from the Green's functions approach and lattice calculations. The nonperturbative solutions for the ghost, gluon and quark propagators from a coupled set of Dyson-Schwinger equations agree almost quantitatively with corresponding lattice results. Similar unquenching effects are found in both approaches. The dynamically generated quark masses are close to `phenomenological' values. The chiral condensate is found to be large.
[ { "created": "Fri, 26 Nov 2004 16:57:09 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fischer", "C. S.", "" ], [ "Alkofer", "R.", "" ] ]
We summarise results for the propagators of Landau gauge QCD from the Green's functions approach and lattice calculations. The nonperturbative solutions for the ghost, gluon and quark propagators from a coupled set of Dyson-Schwinger equations agree almost quantitatively with corresponding lattice results. Similar unquenching effects are found in both approaches. The dynamically generated quark masses are close to `phenomenological' values. The chiral condensate is found to be large.
hep-ph/0210012
Alexander S. Sakharov
Maxim Yu. Khlopov, Sergei G. Rubin and Alexander S. Sakharov
Antimatter regions in the baryon-dominated Universe
Talk given at the XIVth Rencontres de Blois 2002 on Matter-Antimatter Asymmetry, Blois, France, June, 2002, to be published in the proceedings, ed. J. Tran Thanh Van, 4 latex pages, 2 eps figures
null
null
CERN-TH/2002-265
hep-ph astro-ph hep-th
null
Quantum fluctuations of a complex, baryonic charged scalar field caused by inflation can generate large domains, which convert later into antimatter regions. As a result the Universe can become globally matter-dominated, with minor contribution of antimatter regions. The distribution and evolution of such antimatter regions could cause every galaxy to be a harbour of an anti-star globular cluster. At the same time, the scenario does not lead to large-scale isocuvature perturbations, which would disturb observable CMB anisotropy. The existence of one of such antistar globular cluster in our Galaxy does not contradict the observed $\gamma$-ray background, but the expected fluxes of $\bar{\rm ^4He}$ and $\bar{\rm ^3He}$ from such an antimatter object are definitely accessible to the sensitivity of the coming AMS--02 experiment.
[ { "created": "Tue, 1 Oct 2002 17:22:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Khlopov", "Maxim Yu.", "" ], [ "Rubin", "Sergei G.", "" ], [ "Sakharov", "Alexander S.", "" ] ]
Quantum fluctuations of a complex, baryonic charged scalar field caused by inflation can generate large domains, which convert later into antimatter regions. As a result the Universe can become globally matter-dominated, with minor contribution of antimatter regions. The distribution and evolution of such antimatter regions could cause every galaxy to be a harbour of an anti-star globular cluster. At the same time, the scenario does not lead to large-scale isocuvature perturbations, which would disturb observable CMB anisotropy. The existence of one of such antistar globular cluster in our Galaxy does not contradict the observed $\gamma$-ray background, but the expected fluxes of $\bar{\rm ^4He}$ and $\bar{\rm ^3He}$ from such an antimatter object are definitely accessible to the sensitivity of the coming AMS--02 experiment.
1211.4835
Diogo Buarque Franzosi
Diogo Buarque Franzosi, Fabio Maltoni, Cen Zhang
Effective field theory approach to the Higgs lineshape
15 pages, 16 figures
null
10.1103/PhysRevD.87.053015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The phenomenology of unstable particles, including searches and exclusion limits at the LHC, depends significantly on its lineshape. When the width of the resonance is large with respect to its mass, off-shell effects become relevant and the very same definition of width becomes non trivial. Taking a heavy Higgs boson as an example, we propose a new formulation to describe the lineshape via an effective field theory approach. Our method leads to amplitudes that are gauge invariant, respect unitarity and can appropriately describe the lineshape of broad resonances. The application of the method to the following relevant processes for the LHC phenomenology have been considered: gluon fusion, vector boson scattering and $t\bar{t}$ production via weak boson fusion.
[ { "created": "Tue, 20 Nov 2012 19:24:57 GMT", "version": "v1" } ]
2013-03-27
[ [ "Franzosi", "Diogo Buarque", "" ], [ "Maltoni", "Fabio", "" ], [ "Zhang", "Cen", "" ] ]
The phenomenology of unstable particles, including searches and exclusion limits at the LHC, depends significantly on its lineshape. When the width of the resonance is large with respect to its mass, off-shell effects become relevant and the very same definition of width becomes non trivial. Taking a heavy Higgs boson as an example, we propose a new formulation to describe the lineshape via an effective field theory approach. Our method leads to amplitudes that are gauge invariant, respect unitarity and can appropriately describe the lineshape of broad resonances. The application of the method to the following relevant processes for the LHC phenomenology have been considered: gluon fusion, vector boson scattering and $t\bar{t}$ production via weak boson fusion.
hep-ph/0307130
Alfonso Zerwekh
Alfonso R. Zerwekh
Effective Description of a Gauge Field and a Tower of Massive Vector Resonances
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we review an effective description of the interaction of a gauge field with a tower of massive vector fields by introducing a non-diagonal mass matrix in a gauge invariant way. Particular cases of the method with only one vector resonance have been used by the author elsewhere, nevertheless in this paper the method is developed in a general way and and we proof its main features for an arbitrary number of vector resonances. Additionally, we show how to couple the vector resonances with fermions. We find that the method can be useful in order to describe the low energy phenomenology of scenarios like Kaluza-Klein resonances of usual gauge bosons or Technicolor vector resonances and detailed examples are provided.
[ { "created": "Wed, 9 Jul 2003 14:48:36 GMT", "version": "v1" }, { "created": "Sat, 29 Aug 2009 23:58:20 GMT", "version": "v2" } ]
2009-08-30
[ [ "Zerwekh", "Alfonso R.", "" ] ]
In this work we review an effective description of the interaction of a gauge field with a tower of massive vector fields by introducing a non-diagonal mass matrix in a gauge invariant way. Particular cases of the method with only one vector resonance have been used by the author elsewhere, nevertheless in this paper the method is developed in a general way and and we proof its main features for an arbitrary number of vector resonances. Additionally, we show how to couple the vector resonances with fermions. We find that the method can be useful in order to describe the low energy phenomenology of scenarios like Kaluza-Klein resonances of usual gauge bosons or Technicolor vector resonances and detailed examples are provided.
hep-ph/9811316
Hsin-Chia Cheng
Hsin-Chia Cheng, Bogdan A. Dobrescu and Konstantin T. Matchev
Generic and Chiral Extensions of the Supersymmetric Standard Model
33 pages, 2 figures, LaTeX
Nucl.Phys.B543:47-72,1999
10.1016/S0550-3213(99)00012-7
Fermilab-PUB-98/357-T
hep-ph
null
We construct extensions of the Standard Model in which the gauge symmetries and supersymmetry prevent the dangerously large effects that may potentially be induced in a supersymmetric standard model by Planck scale physics. These include baryon number violation, flavor changing neutral currents, the $\mu$ term, and masses for singlet or vector-like fields under the Standard Model gauge group. For this purpose we introduce an extra non-anomalous $U(1)_\mu$ gauge group. Dynamical supersymmetry breaking in a secluded sector triggers the breaking of the $U(1)_\mu$ and generates soft masses for the superpartners via gauge mediation, with the scalars possibly receiving sizable contributions from the $U(1)_\mu$ D-term. We find several classes of complete and calculable models, in which the messengers do not present cosmological problems and neutrino masses can also be accomodated. We derive the sparticle spectrum in these models and study the phenomenological consequences. We give an exhaustive list of the potential experimental signatures and discuss their observability in the upcoming Tevatron runs. One class of models exhibits interesting new discovery channels, namely $WW \not E_T$, $W\gamma \not E_T$ and $WZ \not E_T$, which arise when the next-to-lightest supersymmetric particle is a short-lived $SU(2)_W$ neutralino.
[ { "created": "Thu, 12 Nov 1998 23:34:34 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cheng", "Hsin-Chia", "" ], [ "Dobrescu", "Bogdan A.", "" ], [ "Matchev", "Konstantin T.", "" ] ]
We construct extensions of the Standard Model in which the gauge symmetries and supersymmetry prevent the dangerously large effects that may potentially be induced in a supersymmetric standard model by Planck scale physics. These include baryon number violation, flavor changing neutral currents, the $\mu$ term, and masses for singlet or vector-like fields under the Standard Model gauge group. For this purpose we introduce an extra non-anomalous $U(1)_\mu$ gauge group. Dynamical supersymmetry breaking in a secluded sector triggers the breaking of the $U(1)_\mu$ and generates soft masses for the superpartners via gauge mediation, with the scalars possibly receiving sizable contributions from the $U(1)_\mu$ D-term. We find several classes of complete and calculable models, in which the messengers do not present cosmological problems and neutrino masses can also be accomodated. We derive the sparticle spectrum in these models and study the phenomenological consequences. We give an exhaustive list of the potential experimental signatures and discuss their observability in the upcoming Tevatron runs. One class of models exhibits interesting new discovery channels, namely $WW \not E_T$, $W\gamma \not E_T$ and $WZ \not E_T$, which arise when the next-to-lightest supersymmetric particle is a short-lived $SU(2)_W$ neutralino.
1309.3062
Thibault de Boissi\`ere
Thibault de Boissi\`ere (for the EDELWEISS experiment)
Searches for axions with the EDELWEISS experiment
4 pages, 4 figures, to appear in the proceedings of the 25th "Rencontres de Blois", Blois, France, May 27-31, 2013
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The EDELWEISS experiment primarily aims at the direct detection of WIMPs using germanium bolometers. It is also sensitive to the low-energy electron recoils that would be induced by axions. We present new constraints on the couplings of axions using data from the EDELWEISS-II experiment. Using a total exposure of up to 448~kg.d, we searched for axion-induced electron recoils down to 2.5~keV within four scenarios involving different hypotheses on the origin and couplings of axions. We set a 95~\% CL limit on the coupling to photons $g_{A\gamma}<2.15\times 10^{-9}$~GeV$^{-1}$ in a mass range not fully covered by axion helioscopes. We constrain the coupling to electrons, $g_{Ae} < 2.59\times 10^{-11}$, similar to the more indirect solar neutrino bound. Finally we place a limit on $g_{Ae}\times g_{AN}^{\rm eff}<4.82 \times 10^{-17}$, where $g_{AN}^{\rm eff}$ is the effective axion-nucleon coupling for $^{57}$Fe. Combining these results we fully exclude the mass range $0.91\,{\rm eV}<m_A<80$~keV for DFSZ axions and $5.73\,{\rm eV}<m_A<40$~keV for KSVZ axions.
[ { "created": "Thu, 12 Sep 2013 08:54:49 GMT", "version": "v1" } ]
2019-08-14
[ [ "de Boissière", "Thibault", "", "for the EDELWEISS experiment" ] ]
The EDELWEISS experiment primarily aims at the direct detection of WIMPs using germanium bolometers. It is also sensitive to the low-energy electron recoils that would be induced by axions. We present new constraints on the couplings of axions using data from the EDELWEISS-II experiment. Using a total exposure of up to 448~kg.d, we searched for axion-induced electron recoils down to 2.5~keV within four scenarios involving different hypotheses on the origin and couplings of axions. We set a 95~\% CL limit on the coupling to photons $g_{A\gamma}<2.15\times 10^{-9}$~GeV$^{-1}$ in a mass range not fully covered by axion helioscopes. We constrain the coupling to electrons, $g_{Ae} < 2.59\times 10^{-11}$, similar to the more indirect solar neutrino bound. Finally we place a limit on $g_{Ae}\times g_{AN}^{\rm eff}<4.82 \times 10^{-17}$, where $g_{AN}^{\rm eff}$ is the effective axion-nucleon coupling for $^{57}$Fe. Combining these results we fully exclude the mass range $0.91\,{\rm eV}<m_A<80$~keV for DFSZ axions and $5.73\,{\rm eV}<m_A<40$~keV for KSVZ axions.
2402.18635
Stefano Forte
The NNPDF Collaboration: Richard D. Ball, Andrea Barontini, Alessandro Candido, Stefano Carrazza, Juan Cruz-Martinez, Luigi Del Debbio, Stefano Forte, Tommaso Giani, Felix Hekhorn, Zahari Kassabov, Niccol\`o Laurenti, Giacomo Magni, Emanuele R. Nocera, Tanjona R. Rabemananjara, Juan Rojo, Christopher Schwan, Roy Stegeman and Maria Ubiali
The Path to N$^3$LO Parton Distributions
63 pages, 41 figures. Final version, as published in EPJC. Various clarifications added. Fig 2.9 and Tab. 4.6, 5.1 and 5.2 added. In particular, comparison to approximate YR4 estimate of PDF uncertainties added (Tab 4.1, 4.2 and associate discussion in sect. 5)
null
null
Nikhef-2023-020, TIF-UNIMI-2023-23, Edinburgh 2023/29
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the existing leading (LO), next-to-leading (NLO), and next-to-next-to-leading order (NNLO) NNPDF4.0 sets of parton distribution functions (PDFs) to approximate next-to-next-to-next-to-leading order (aN$^3$LO). We construct an approximation to the N$^3$LO splitting functions that includes all available partial information from both fixed-order computations and from small and large $x$ resummation, and estimate the uncertainty on this approximation by varying the set of basis functions used to construct the approximation. We include known N$^3$LO corrections to deep-inelastic scattering structure functions and extend the FONLL general-mass scheme to $\mathcal{O}\left( \alpha_s^3\right)$ accuracy. We determine a set of aN$^3$LO PDFs by accounting both for the uncertainty on splitting functions due to the incomplete knowledge of N$^3$LO terms, and to the uncertainty related to missing higher corrections (MHOU), estimated by scale variation, through a theory covariance matrix formalism. We assess the perturbative stability of the resulting PDFs, we study the impact of MHOUs on them, and we compare our results to the aN$^3$LO PDFs from the MSHT group. We examine the phenomenological impact of aN$^3$LO corrections on parton luminosities at the LHC, and give a first assessment of the impact of aN$^3$LO PDFs on the Higgs and Drell-Yan total production cross-sections. We find that the aN$^3$LO NNPDF4.0 PDFs are consistent within uncertainties with their NNLO counterparts, that they improve the description of the global dataset and the perturbative convergence of Higgs and Drell-Yan cross-sections, and that MHOUs on PDFs decrease substantially with the increase of perturbative order.
[ { "created": "Wed, 28 Feb 2024 19:00:01 GMT", "version": "v1" }, { "created": "Fri, 5 Jul 2024 09:26:50 GMT", "version": "v2" } ]
2024-07-08
[ [ "The NNPDF Collaboration", "", "" ], [ "Ball", "Richard D.", "" ], [ "Barontini", "Andrea", "" ], [ "Candido", "Alessandro", "" ], [ "Carrazza", "Stefano", "" ], [ "Cruz-Martinez", "Juan", "" ], [ "Del Debbio", "Luigi", "" ], [ "Forte", "Stefano", "" ], [ "Giani", "Tommaso", "" ], [ "Hekhorn", "Felix", "" ], [ "Kassabov", "Zahari", "" ], [ "Laurenti", "Niccolò", "" ], [ "Magni", "Giacomo", "" ], [ "Nocera", "Emanuele R.", "" ], [ "Rabemananjara", "Tanjona R.", "" ], [ "Rojo", "Juan", "" ], [ "Schwan", "Christopher", "" ], [ "Stegeman", "Roy", "" ], [ "Ubiali", "Maria", "" ] ]
We extend the existing leading (LO), next-to-leading (NLO), and next-to-next-to-leading order (NNLO) NNPDF4.0 sets of parton distribution functions (PDFs) to approximate next-to-next-to-next-to-leading order (aN$^3$LO). We construct an approximation to the N$^3$LO splitting functions that includes all available partial information from both fixed-order computations and from small and large $x$ resummation, and estimate the uncertainty on this approximation by varying the set of basis functions used to construct the approximation. We include known N$^3$LO corrections to deep-inelastic scattering structure functions and extend the FONLL general-mass scheme to $\mathcal{O}\left( \alpha_s^3\right)$ accuracy. We determine a set of aN$^3$LO PDFs by accounting both for the uncertainty on splitting functions due to the incomplete knowledge of N$^3$LO terms, and to the uncertainty related to missing higher corrections (MHOU), estimated by scale variation, through a theory covariance matrix formalism. We assess the perturbative stability of the resulting PDFs, we study the impact of MHOUs on them, and we compare our results to the aN$^3$LO PDFs from the MSHT group. We examine the phenomenological impact of aN$^3$LO corrections on parton luminosities at the LHC, and give a first assessment of the impact of aN$^3$LO PDFs on the Higgs and Drell-Yan total production cross-sections. We find that the aN$^3$LO NNPDF4.0 PDFs are consistent within uncertainties with their NNLO counterparts, that they improve the description of the global dataset and the perturbative convergence of Higgs and Drell-Yan cross-sections, and that MHOUs on PDFs decrease substantially with the increase of perturbative order.
2203.08056
Cora Dvorkin
Cora Dvorkin, Siddharth Mishra-Sharma, Brian Nord, V. Ashley Villar, Camille Avestruz, Keith Bechtol, Aleksandra \'Ciprijanovi\'c, Andrew J. Connolly, Lehman H. Garrison, Gautham Narayan, and Francisco Villaescusa-Navarro
Machine Learning and Cosmology
Contribution to Snowmass 2021. 32 pages
null
null
null
hep-ph astro-ph.CO astro-ph.IM cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Methods based on machine learning have recently made substantial inroads in many corners of cosmology. Through this process, new computational tools, new perspectives on data collection, model development, analysis, and discovery, as well as new communities and educational pathways have emerged. Despite rapid progress, substantial potential at the intersection of cosmology and machine learning remains untapped. In this white paper, we summarize current and ongoing developments relating to the application of machine learning within cosmology and provide a set of recommendations aimed at maximizing the scientific impact of these burgeoning tools over the coming decade through both technical development as well as the fostering of emerging communities.
[ { "created": "Tue, 15 Mar 2022 16:50:46 GMT", "version": "v1" } ]
2022-03-16
[ [ "Dvorkin", "Cora", "" ], [ "Mishra-Sharma", "Siddharth", "" ], [ "Nord", "Brian", "" ], [ "Villar", "V. Ashley", "" ], [ "Avestruz", "Camille", "" ], [ "Bechtol", "Keith", "" ], [ "Ćiprijanović", "Aleksandra", "" ], [ "Connolly", "Andrew J.", "" ], [ "Garrison", "Lehman H.", "" ], [ "Narayan", "Gautham", "" ], [ "Villaescusa-Navarro", "Francisco", "" ] ]
Methods based on machine learning have recently made substantial inroads in many corners of cosmology. Through this process, new computational tools, new perspectives on data collection, model development, analysis, and discovery, as well as new communities and educational pathways have emerged. Despite rapid progress, substantial potential at the intersection of cosmology and machine learning remains untapped. In this white paper, we summarize current and ongoing developments relating to the application of machine learning within cosmology and provide a set of recommendations aimed at maximizing the scientific impact of these burgeoning tools over the coming decade through both technical development as well as the fostering of emerging communities.
hep-ph/0511018
Alexandre Kisselev
A.V. Kisselev and V.A. Petrov
Kaluza-Klein gravitons at the LHC and in extensive air showers
8 pages, 4 figures, talk given at the International Conference on Interconnection between High Energy Physics and Astroparticle Physics: From Colliders to Cosmic Rays, 7-13 September 2005, Prague, Czech Republic
Czech.J.Phys. 56 (2006) A91-A97
10.1007/s10582-006-0145-z
null
hep-ph astro-ph
null
The small curvature option of the Randall-Sundrum model with two branes is considered which has almost continuous spectrum of low-mass Kaluza-Klein gravitons. It is shown that gravity effects related with these excitations can be detected in double diffractive events at the LHC and in inclined air showers induced by interactions of cosmic neutrinos with atmospheric nucleons at ultra-high energies.
[ { "created": "Wed, 2 Nov 2005 13:32:21 GMT", "version": "v1" } ]
2015-06-25
[ [ "Kisselev", "A. V.", "" ], [ "Petrov", "V. A.", "" ] ]
The small curvature option of the Randall-Sundrum model with two branes is considered which has almost continuous spectrum of low-mass Kaluza-Klein gravitons. It is shown that gravity effects related with these excitations can be detected in double diffractive events at the LHC and in inclined air showers induced by interactions of cosmic neutrinos with atmospheric nucleons at ultra-high energies.
2303.04999
Chia-Min Lin
Chia-Min Lin
Uniform Rate Inflation
9 pages, 2 figures, to be published in JCAP
null
10.1088/1475-7516/2023/04/037
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, I consider an inflation model with a quadratic potential and a negative cosmological constant. An analytical solution of the equation of motion for the inflaton field is found without slow-roll approximation. The result is that the inflation field is rolling at a constant speed. The prediction for cosmological perturbation is calculated.
[ { "created": "Thu, 9 Mar 2023 02:44:29 GMT", "version": "v1" }, { "created": "Wed, 5 Apr 2023 06:39:09 GMT", "version": "v2" } ]
2023-04-19
[ [ "Lin", "Chia-Min", "" ] ]
In this work, I consider an inflation model with a quadratic potential and a negative cosmological constant. An analytical solution of the equation of motion for the inflaton field is found without slow-roll approximation. The result is that the inflation field is rolling at a constant speed. The prediction for cosmological perturbation is calculated.
1803.09748
Jose Manuel Alarc\'on
J. M. Alarc\'on, C. Weiss
Accurate nucleon electromagnetic form factors from dispersively improved chiral effective field theory
5 pages, 3 figures, 2 tables
null
10.1016/j.physletb.2018.07.060
JLAB-THY-18-2675
hep-ph hep-lat nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a theoretical parametrization of the nucleon electromagnetic form factors (FFs) based on a combination of chiral effective field theory and dispersion analysis. The isovector spectral functions on the two-pion cut are computed using elastic unitarity, chiral pion-nucleon amplitudes, and timelike pion FF data. Higher-mass isovector and isoscalar t-channel states are described by effective poles, whose strength is fixed by sum rules (charges, radii). Excellent agreement with the spacelike proton and neutron FF data is achieved up to Q^2 \sim 1 GeV^2. Our parametrization provides proper analyticity and theoretical uncertainty estimates and can be used for low-Q^2 FF studies and proton radius extraction.
[ { "created": "Mon, 26 Mar 2018 18:00:00 GMT", "version": "v1" } ]
2018-08-15
[ [ "Alarcón", "J. M.", "" ], [ "Weiss", "C.", "" ] ]
We present a theoretical parametrization of the nucleon electromagnetic form factors (FFs) based on a combination of chiral effective field theory and dispersion analysis. The isovector spectral functions on the two-pion cut are computed using elastic unitarity, chiral pion-nucleon amplitudes, and timelike pion FF data. Higher-mass isovector and isoscalar t-channel states are described by effective poles, whose strength is fixed by sum rules (charges, radii). Excellent agreement with the spacelike proton and neutron FF data is achieved up to Q^2 \sim 1 GeV^2. Our parametrization provides proper analyticity and theoretical uncertainty estimates and can be used for low-Q^2 FF studies and proton radius extraction.
hep-ph/9903435
Anjan Joshipura
Anjan S. Joshipura and Sudhir K. Vempati
Sneutrino Vacuum Expectation Values and Neutrino Anomalies Through Trilinear R-parity Violation
References added and typos corrected
Phys.Rev.D60:111303,1999
10.1103/PhysRevD.60.111303
PRL-TH-99/001
hep-ph
null
Neutrino mass spectrum is reanalyzed in supersymmetric models with explicit trilinear $R$ violation. Models in this category are argued to provide simultaneous solution to the solar and atmospheric neutrino anomalies. It is shown specifically that large mixing and hierarchical masses needed for the vacuum solution of neutrino anomalies arise naturally in these models without requiring any additional symmetries or hierarchies among the trilinear couplings.
[ { "created": "Mon, 22 Mar 1999 11:15:24 GMT", "version": "v1" }, { "created": "Thu, 8 Apr 1999 11:55:34 GMT", "version": "v2" } ]
2009-12-30
[ [ "Joshipura", "Anjan S.", "" ], [ "Vempati", "Sudhir K.", "" ] ]
Neutrino mass spectrum is reanalyzed in supersymmetric models with explicit trilinear $R$ violation. Models in this category are argued to provide simultaneous solution to the solar and atmospheric neutrino anomalies. It is shown specifically that large mixing and hierarchical masses needed for the vacuum solution of neutrino anomalies arise naturally in these models without requiring any additional symmetries or hierarchies among the trilinear couplings.
hep-ph/9811271
Johannes Bluemlein
Johannes Bl\"umlein, Edward Boos, and Alexander Kryukov
Leptoquark Pair Production Cross Sections at Hadron Colliders
1 reference changed
null
null
DESY 97-067
hep-ph
null
A compilation is given of the pair production cross sections for scalar and vector leptoquarks in the kinematic range of the hadron colliders Tevatron and LHC.
[ { "created": "Sat, 7 Nov 1998 21:54:07 GMT", "version": "v1" }, { "created": "Wed, 11 Nov 1998 15:43:57 GMT", "version": "v2" } ]
2007-05-23
[ [ "Blümlein", "Johannes", "" ], [ "Boos", "Edward", "" ], [ "Kryukov", "Alexander", "" ] ]
A compilation is given of the pair production cross sections for scalar and vector leptoquarks in the kinematic range of the hadron colliders Tevatron and LHC.
hep-ph/0007293
Steven D. Bass
Steven D. Bass, Stefan Wetzel and Wolfram Weise
Axial U(1) dynamics in eta and eta' photoproduction
19 pages, 9 figures
Nucl.Phys. A686 (2001) 429-446
10.1016/S0375-9474(00)00574-1
TUM/T39-00-09, ECT-00-006
hep-ph
null
We discuss the sensitivity of eta and eta' photoproduction near threshold to the gluonic OZI breaking parameters in the U_A(1)-extended effective chiral Lagrangian for low-energy QCD. Our coupled-channels analysis hints at a strong correlation between the gluon-induced contributions to the eta' mass and the low-energy pp -> pp eta' reaction and the near-threshold behaviour of the gamma p -> eta p cross-section.
[ { "created": "Wed, 26 Jul 2000 11:59:48 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bass", "Steven D.", "" ], [ "Wetzel", "Stefan", "" ], [ "Weise", "Wolfram", "" ] ]
We discuss the sensitivity of eta and eta' photoproduction near threshold to the gluonic OZI breaking parameters in the U_A(1)-extended effective chiral Lagrangian for low-energy QCD. Our coupled-channels analysis hints at a strong correlation between the gluon-induced contributions to the eta' mass and the low-energy pp -> pp eta' reaction and the near-threshold behaviour of the gamma p -> eta p cross-section.
hep-ph/9410233
John Terning
John Terning
Chiral Technicolor and Precision Electroweak Measurements
19 pages, LaTeX, BUHEP-94-27
Phys.Lett.B344:279-286,1995
10.1016/0370-2693(94)01506-8
null
hep-ph
null
I consider the possibility that electroweak symmetry is broken by a strongly interacting chiral gauge theory. I argue that some of the discrepancies between precision electroweak measurements and the predictions of QCD-like technicolor models can be resolved if technicolor is a chiral gauge theory. I present a toy technicolor model which demonstrates this idea, and gives $ m_t \gg m_b$, with a small value for $\Delta\rho_* \equiv \alpha T $, and small corrections to $Z \rightarrow b \overline{b}$.
[ { "created": "Thu, 6 Oct 1994 17:35:51 GMT", "version": "v1" } ]
2014-11-17
[ [ "Terning", "John", "" ] ]
I consider the possibility that electroweak symmetry is broken by a strongly interacting chiral gauge theory. I argue that some of the discrepancies between precision electroweak measurements and the predictions of QCD-like technicolor models can be resolved if technicolor is a chiral gauge theory. I present a toy technicolor model which demonstrates this idea, and gives $ m_t \gg m_b$, with a small value for $\Delta\rho_* \equiv \alpha T $, and small corrections to $Z \rightarrow b \overline{b}$.
hep-ph/9502321
null
W. Buchmuller, Z. Fodor and A. Hebecker
THERMODYNAMICS OF THE ELECTROWEAK PHASE TRANSITION
22 pages, 9 figures (as .uu files), ps file available by anonymous ftp at ftp://x4u2.desy.de/pub/preprints/desy/1995/desy95-028.ps
Nucl.Phys.B447:317-339,1995
10.1016/0550-3213(95)00254-P
DESY 95-028
hep-ph hep-lat
null
We discuss several general aspects of the free energy of the standard model at high temperatures. In particular the Clausius-Clapeyron equation is shown to yield a relation between the latent heat and the jump in the order parameter. The free energy is calculated as function of temperature in resummed perturbation theory to two-loop order. A new resummation procedure is proposed in which the symmetric phase and the Higgs phase are treated differently. A quantitative description of the phase transition is achieved for Higgs masses below $\sim 70$ GeV. The results are found to be in agreement with recent numerical simulations on large lattices. The phase transition provides no evidence for strong non-perturbative effects in the symmetric phase.
[ { "created": "Thu, 16 Feb 1995 14:10:23 GMT", "version": "v1" } ]
2016-09-01
[ [ "Buchmuller", "W.", "" ], [ "Fodor", "Z.", "" ], [ "Hebecker", "A.", "" ] ]
We discuss several general aspects of the free energy of the standard model at high temperatures. In particular the Clausius-Clapeyron equation is shown to yield a relation between the latent heat and the jump in the order parameter. The free energy is calculated as function of temperature in resummed perturbation theory to two-loop order. A new resummation procedure is proposed in which the symmetric phase and the Higgs phase are treated differently. A quantitative description of the phase transition is achieved for Higgs masses below $\sim 70$ GeV. The results are found to be in agreement with recent numerical simulations on large lattices. The phase transition provides no evidence for strong non-perturbative effects in the symmetric phase.
2107.01293
Johannes Bl\"umlein
J. Bl\"umlein and M. Saragnese
The N$^3$LO Scheme-invariant QCD Evolution of the Non-singlet Structure Functions \boldmath $F^{\rm NS}_2(x,Q^2)$ and $g_1^{\rm NS}(x,Q^2)$
14 pages Latex, 12 figures
null
10.1016/j.physletb.2021.136589
DESY 21--096, DO--TH 21/21, SAGEX--21--13--E
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We present the scheme-invariant unpolarized and polarized flavor non-singlet evolution equation to N$^3$LO for the structure functions $F_2(x,Q^2)$ and $g_1(x,Q^2)$ including the charm- and bottom quark effects in the asymptotic representation. The corresponding evolution is based on the experimental measurement of the non-singlet structure functions at a starting scale $Q_0^2$. In this way the evolution does only depend on the strong coupling constant $\alpha_s(M_Z)$ or the QCD scale $\Lambda_{\rm QCD}$ and the charm and bottom quark masses $m_c$ and $m_b$ and provides one of the cleanest ways to measure the strong coupling constant in future high luminosity deep-inelastic scattering experiments. The yet unknown parts of the 4-loop anomalous dimensions introduce only a marginal error in this analysis.
[ { "created": "Fri, 2 Jul 2021 22:13:55 GMT", "version": "v1" } ]
2021-09-15
[ [ "Blümlein", "J.", "" ], [ "Saragnese", "M.", "" ] ]
We present the scheme-invariant unpolarized and polarized flavor non-singlet evolution equation to N$^3$LO for the structure functions $F_2(x,Q^2)$ and $g_1(x,Q^2)$ including the charm- and bottom quark effects in the asymptotic representation. The corresponding evolution is based on the experimental measurement of the non-singlet structure functions at a starting scale $Q_0^2$. In this way the evolution does only depend on the strong coupling constant $\alpha_s(M_Z)$ or the QCD scale $\Lambda_{\rm QCD}$ and the charm and bottom quark masses $m_c$ and $m_b$ and provides one of the cleanest ways to measure the strong coupling constant in future high luminosity deep-inelastic scattering experiments. The yet unknown parts of the 4-loop anomalous dimensions introduce only a marginal error in this analysis.
hep-ph/0306180
Asmaa Abada
Asmaa Abada and Marta Losada
Leptogenesis with four gauge singlets
13 pages, 9 PS figures, REVTeX
Nucl.Phys. B673 (2003) 319-330
10.1016/j.nuclphysb.2003.09.030
LPT Orsay/03-40, CI-UAN 02-15T
hep-ph
null
We consider a generic type of leptogenesis model which can successfully produce the correct value of the observed baryon number to entropy ratio. The main feature of this model is that it is a simple TeV scale model, a scale accessible in near future machines, with a minimal particle content. Both supersymmetric and non-supersymmetric versions of the model are feasible. This model also gives left-handed neutrino masses compatible with all current data from direct and indirect neutrino experiments.
[ { "created": "Thu, 19 Jun 2003 17:16:51 GMT", "version": "v1" } ]
2010-04-05
[ [ "Abada", "Asmaa", "" ], [ "Losada", "Marta", "" ] ]
We consider a generic type of leptogenesis model which can successfully produce the correct value of the observed baryon number to entropy ratio. The main feature of this model is that it is a simple TeV scale model, a scale accessible in near future machines, with a minimal particle content. Both supersymmetric and non-supersymmetric versions of the model are feasible. This model also gives left-handed neutrino masses compatible with all current data from direct and indirect neutrino experiments.
2207.05015
Francesco Giovanni Celiberto
Francesco Giovanni Celiberto, Alessandro Papa
Mueller-Navelet jets at the LHC: hunting data with azimuthal distributions
26 pages, 9 figures, 246 references, version published in Phys. Rev. D
Phys. Rev. D 106 (2022) 11, 114004
10.1103/PhysRevD.106.114004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By making use of the hybrid collinear and high-energy factorization, where the BFKL resummation of leading and next-to-leading energy logarithms is combined with the standard description in terms of collinear parton densities, we compare predictions for Mueller-Navelet jet rapidity and angular differential rates with data collected by CMS at $\sqrt{s} = 7$ TeV. We provide an evidence that the study of azimuthal distributions, calculated as a Fourier sum of correlation moments and embodying the high-energy signal coming from all conformal-spin modes, permits us to overcome the well-known issues emerging in the description of Mueller-Navelet final states at natural values of the renormalization scale. We come out with a clear indication that the next-to-leading BFKL description of these observables at natural scales is valid when the rapidity interval between the two jets is large, and it allows us to catch the core high-energy dynamics emerging from data.
[ { "created": "Mon, 11 Jul 2022 17:06:57 GMT", "version": "v1" }, { "created": "Tue, 6 Dec 2022 18:24:00 GMT", "version": "v2" } ]
2022-12-07
[ [ "Celiberto", "Francesco Giovanni", "" ], [ "Papa", "Alessandro", "" ] ]
By making use of the hybrid collinear and high-energy factorization, where the BFKL resummation of leading and next-to-leading energy logarithms is combined with the standard description in terms of collinear parton densities, we compare predictions for Mueller-Navelet jet rapidity and angular differential rates with data collected by CMS at $\sqrt{s} = 7$ TeV. We provide an evidence that the study of azimuthal distributions, calculated as a Fourier sum of correlation moments and embodying the high-energy signal coming from all conformal-spin modes, permits us to overcome the well-known issues emerging in the description of Mueller-Navelet final states at natural values of the renormalization scale. We come out with a clear indication that the next-to-leading BFKL description of these observables at natural scales is valid when the rapidity interval between the two jets is large, and it allows us to catch the core high-energy dynamics emerging from data.
1512.03581
Pradipta Ghosh
Joydeep Chakrabortty, Pradipta Ghosh, Subhadeep Mondal, Tripurari Srivastava
Reconciling $(g-2)_\mu$ and charged lepton flavour violating processes through a doubly charged scalar
17 pages double column, 8 .pdf figures, pdflatex, matches with the published version in Physical Review D
Phys. Rev. D 93, 115004 (2016)
10.1103/PhysRevD.93.115004
CPHT-RR054.1115, LPT-Orsay-15-89, HRI-RECAPP-2015-016
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we investigate the phenomenological consequences of a doubly charged scalar which may belong to different uncoloured scalar multiplets. This doubly charged scalar couples to the charged leptons as well as gauge bosons, which we parametrize in a model independent way. Restricting ourselves in the regime of conserved charged-parity (CP), we assume only a few non-zero Yukawa couplings ($y_{\mu \ell}$, where $\ell=e,\mu,\tau$) between the doubly charged scalar and the charged leptons. Our choices allow the doubly charged scalar to impinge low-energy processes like anomalous magnetic moment of muon and a few possible charged lepton flavour violating (CLFV) processes. These same Yukawa couplings are also instrumental in producing same-sign dilepton signatures at the LHC. In this article we examine the impact of individual contributions from the diagonal and off-diagonal Yukawa couplings in the light of muon $(g-2)$ excess. Subsequently, we use the derived information to inquire the possible CLFV processes and finally the collider signals from the decay of a doubly charged scalar. Our simplified analyses, depending on the mass of doubly charged scalar, provide a good estimate for the magnitude of the concerned Yukawa couplings. Our findings would appear resourceful to test the phenomenological significance of a doubly charged scalar by using complementary information from muon $(g-2)$, CLFV and the collider experiments.
[ { "created": "Fri, 11 Dec 2015 10:35:02 GMT", "version": "v1" }, { "created": "Mon, 16 May 2016 04:21:51 GMT", "version": "v2" }, { "created": "Sun, 5 Jun 2016 20:52:01 GMT", "version": "v3" } ]
2016-06-07
[ [ "Chakrabortty", "Joydeep", "" ], [ "Ghosh", "Pradipta", "" ], [ "Mondal", "Subhadeep", "" ], [ "Srivastava", "Tripurari", "" ] ]
In this work, we investigate the phenomenological consequences of a doubly charged scalar which may belong to different uncoloured scalar multiplets. This doubly charged scalar couples to the charged leptons as well as gauge bosons, which we parametrize in a model independent way. Restricting ourselves in the regime of conserved charged-parity (CP), we assume only a few non-zero Yukawa couplings ($y_{\mu \ell}$, where $\ell=e,\mu,\tau$) between the doubly charged scalar and the charged leptons. Our choices allow the doubly charged scalar to impinge low-energy processes like anomalous magnetic moment of muon and a few possible charged lepton flavour violating (CLFV) processes. These same Yukawa couplings are also instrumental in producing same-sign dilepton signatures at the LHC. In this article we examine the impact of individual contributions from the diagonal and off-diagonal Yukawa couplings in the light of muon $(g-2)$ excess. Subsequently, we use the derived information to inquire the possible CLFV processes and finally the collider signals from the decay of a doubly charged scalar. Our simplified analyses, depending on the mass of doubly charged scalar, provide a good estimate for the magnitude of the concerned Yukawa couplings. Our findings would appear resourceful to test the phenomenological significance of a doubly charged scalar by using complementary information from muon $(g-2)$, CLFV and the collider experiments.
hep-ph/0112345
Hiroshi Nunokawa
Takaaki Kajita, Hisakazu Minakata and Hiroshi Nunokawa
Method for Determination of $|U_{e3}|$ in Neutrino Oscillation Appearance Experiments
15 pages, 3 figures, minor corrections, final version to appear in PLB
Phys.Lett. B528 (2002) 245-252
10.1016/S0370-2693(02)01231-5
IFT-P.006/2002
hep-ph
null
We point out that determination of the MNS matrix element |U_{e3}| = s_{13} in long-baseline \nu_{\mu} \to \nu_e neutrino oscillation experiments suffers from large intrinsic uncertainty due to the unknown CP violating phase \delta and sign of \Delta m^2_{13}. We propose a new strategy for accurate determination of $\theta_{13}$; tune the beam energy at the oscillation maximum and do the measurement both in neutrino and antineutrino channels. We show that it automatically resolves the problem of parameter ambiguities which involves \delta, \theta_{13}, and the sign of \Delta m^2_{13}.
[ { "created": "Fri, 28 Dec 2001 10:11:11 GMT", "version": "v1" }, { "created": "Tue, 5 Feb 2002 18:09:32 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kajita", "Takaaki", "" ], [ "Minakata", "Hisakazu", "" ], [ "Nunokawa", "Hiroshi", "" ] ]
We point out that determination of the MNS matrix element |U_{e3}| = s_{13} in long-baseline \nu_{\mu} \to \nu_e neutrino oscillation experiments suffers from large intrinsic uncertainty due to the unknown CP violating phase \delta and sign of \Delta m^2_{13}. We propose a new strategy for accurate determination of $\theta_{13}$; tune the beam energy at the oscillation maximum and do the measurement both in neutrino and antineutrino channels. We show that it automatically resolves the problem of parameter ambiguities which involves \delta, \theta_{13}, and the sign of \Delta m^2_{13}.
0801.0958
Kazem Azizi
T. M. Aliev, K. Azizi, A. Ozpineci
QCD sum rules analysis of the $B_{s}\to D_{sJ}(2460)l\nu $ decay
Talk at the International Conference on Hadron Physics TROIA'07, 30 Aug. - 3 Sept. 2007, Canakkale, Turkey
null
null
null
hep-ph
null
Using three point QCD sum rules method, the form factors relevant to the semileptonic $B_{s}\to D_{sJ}(2460)\ell\nu$ decay are calculated. The $q^2$ dependencies of these form factors are evaluated. The dependence of the asymmetry parameter $\alpha$, characterizing the polarization of $D_{sJ}$ meson, on $q^2$ is studied. This study gives useful information about the structure of the $D_{sJ}$ meson. Finally the branching ratio of this decay is also estimated and is shown that it can be easily detected at LHC.
[ { "created": "Mon, 7 Jan 2008 12:30:24 GMT", "version": "v1" } ]
2008-01-08
[ [ "Aliev", "T. M.", "" ], [ "Azizi", "K.", "" ], [ "Ozpineci", "A.", "" ] ]
Using three point QCD sum rules method, the form factors relevant to the semileptonic $B_{s}\to D_{sJ}(2460)\ell\nu$ decay are calculated. The $q^2$ dependencies of these form factors are evaluated. The dependence of the asymmetry parameter $\alpha$, characterizing the polarization of $D_{sJ}$ meson, on $q^2$ is studied. This study gives useful information about the structure of the $D_{sJ}$ meson. Finally the branching ratio of this decay is also estimated and is shown that it can be easily detected at LHC.
1007.4235
Kohei Kamada
Takeshi Chiba, Kohei Kamada, Shinta Kasuya, and Masahide Yamaguchi
Fate of thermal log type Q balls
10 pages, 7 figures, Ver.2, published version
Phys.Rev.D82:103534,2010
10.1103/PhysRevD.82.103534
RESCEU-17/10
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study time evolution of the $Q$ ball in thermal logarithmic potential using lattice simulations. As the temperature decreases due to the cosmic expansion, the thermal logarithmic term in the potential is eventually overcome by a mass term, and we confirm that the $Q$ ball transforms from the thick-wall type to the thin-wall type for a positive coefficient of radiative corrections to the mass term, as recently suggested. Moreover, we find that the $Q$ ball finally "melts down" when the $Q$-ball solution disappears. We also discuss the effects of this phenomenon on the detectability of gravitational waves from the $Q$-ball formation.
[ { "created": "Sat, 24 Jul 2010 00:43:00 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 2010 03:53:23 GMT", "version": "v2" } ]
2010-12-23
[ [ "Chiba", "Takeshi", "" ], [ "Kamada", "Kohei", "" ], [ "Kasuya", "Shinta", "" ], [ "Yamaguchi", "Masahide", "" ] ]
We study time evolution of the $Q$ ball in thermal logarithmic potential using lattice simulations. As the temperature decreases due to the cosmic expansion, the thermal logarithmic term in the potential is eventually overcome by a mass term, and we confirm that the $Q$ ball transforms from the thick-wall type to the thin-wall type for a positive coefficient of radiative corrections to the mass term, as recently suggested. Moreover, we find that the $Q$ ball finally "melts down" when the $Q$-ball solution disappears. We also discuss the effects of this phenomenon on the detectability of gravitational waves from the $Q$-ball formation.
hep-ph/9306308
Kingman Cheung
kingman Cheung
Standard Model Higgs Boson at Linear Photon Colliders
(Talk given at the "Workshop on Physics and Experiments with Linear $e^+e^-$ Collider", Waikoloa, Kona, Hawaii), LaTex, 7 pages, 4 figures not inlcuded, NUHEP-TH-93-15
null
null
null
hep-ph
null
We will summarize some aspects of the standard model Higgs boson at high energy $\gamma\gamma$ colliders, where the photon beams are realized by the laser backscattering method, including the direct Higgs boson production via $\gamma\gamma\rightarrow H$, and the measurement of the Yukawa coupling via the channel $\gamma\gamma\rightarrow t\bar tH$.
[ { "created": "Wed, 23 Jun 1993 18:39:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cheung", "kingman", "" ] ]
We will summarize some aspects of the standard model Higgs boson at high energy $\gamma\gamma$ colliders, where the photon beams are realized by the laser backscattering method, including the direct Higgs boson production via $\gamma\gamma\rightarrow H$, and the measurement of the Yukawa coupling via the channel $\gamma\gamma\rightarrow t\bar tH$.
hep-ph/0102284
Maksim L. Nekrasov
M. L. Nekrasov
Gauge-invariant description of W-pair production in NLO approximation
7 pages, latex, 2 eps-figures. Talk presented at the Research Workshop "Calculations for Modern and Future Colliders" Dubna, July 2000, and at the XVth International Workshop "High Energy Physics and Quantum Field Theory", Tver, September 2000
null
null
IHEP 2000-63
hep-ph
null
The processes $e^{+}e^{-} \to 4f(\gamma)$ mediated by W-pair (and single) production are considered in the framework of the modified perturbation theory, based on the expansion of probability in powers of the coupling constant instead of amplitude. A full set of one-loop corrections to cross-section, and two-loop corrections to self-energy of unstable particles are completely taken into consideration. It is shown that the manifestly non-factorizable corrections do not make contributions into the next-to-leading-order approximation. Moreover, the colour reconnection does not make contributions within this precision, either. The rest of the corrections together with the leading-order contribution provide the gauge-invariant description of the processes.
[ { "created": "Fri, 23 Feb 2001 09:40:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nekrasov", "M. L.", "" ] ]
The processes $e^{+}e^{-} \to 4f(\gamma)$ mediated by W-pair (and single) production are considered in the framework of the modified perturbation theory, based on the expansion of probability in powers of the coupling constant instead of amplitude. A full set of one-loop corrections to cross-section, and two-loop corrections to self-energy of unstable particles are completely taken into consideration. It is shown that the manifestly non-factorizable corrections do not make contributions into the next-to-leading-order approximation. Moreover, the colour reconnection does not make contributions within this precision, either. The rest of the corrections together with the leading-order contribution provide the gauge-invariant description of the processes.
2011.08415
Hisakazu Minakata
Hisakazu Minakata
Neutrino amplitude decomposition in matter
An overall factor $\sin 2 \phi$ lacked in $P(\nu_{e} \rightarrow \nu_{e})^{(1)}$ recovered
Phys. Rev. D 103, 053004 (2021)
10.1103/PhysRevD.103.053004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Observation of the interference between the atmospheric-scale and solar-scale oscillations is one of the challenging and tantalizing goals of the ongoing and upcoming neutrino experiments. An inevitable first step required for such analyses is to establish the way of how the oscillation $S$ matrix can be decomposed into the atmospheric and solar waves, the procedure dubbed as the amplitude decomposition. In this paper, with use of the perturbative framework proposed by Denton et al. (DMP), we establish the prescription for amplitude decomposition which covers the whole kinematical region of the terrestrial neutrino experiments. We analyze the limits to the atmospheric- and solar-resonance regions to argue that the dynamical two modes of the DMP decomposition can be interpreted as the matter-dressed atmospheric and solar oscillations. The expressions of the oscillation probability, which are decomposed into the non-interference and interference terms, are derived for all the relevant flavor oscillation channels. Through construction of the DMP decomposition, we reveal the nature of $\psi$ ($\theta_{12}$ in matter) symmetry as due to the $S$ matrix rephasing invariance. A new picture of the DMP perturbation theory emerged, a unified perturbative framework for neutrino oscillation in earth matter.
[ { "created": "Tue, 17 Nov 2020 04:24:17 GMT", "version": "v1" }, { "created": "Wed, 17 Feb 2021 00:26:28 GMT", "version": "v2" }, { "created": "Tue, 22 Jun 2021 03:13:39 GMT", "version": "v3" } ]
2021-06-23
[ [ "Minakata", "Hisakazu", "" ] ]
Observation of the interference between the atmospheric-scale and solar-scale oscillations is one of the challenging and tantalizing goals of the ongoing and upcoming neutrino experiments. An inevitable first step required for such analyses is to establish the way of how the oscillation $S$ matrix can be decomposed into the atmospheric and solar waves, the procedure dubbed as the amplitude decomposition. In this paper, with use of the perturbative framework proposed by Denton et al. (DMP), we establish the prescription for amplitude decomposition which covers the whole kinematical region of the terrestrial neutrino experiments. We analyze the limits to the atmospheric- and solar-resonance regions to argue that the dynamical two modes of the DMP decomposition can be interpreted as the matter-dressed atmospheric and solar oscillations. The expressions of the oscillation probability, which are decomposed into the non-interference and interference terms, are derived for all the relevant flavor oscillation channels. Through construction of the DMP decomposition, we reveal the nature of $\psi$ ($\theta_{12}$ in matter) symmetry as due to the $S$ matrix rephasing invariance. A new picture of the DMP perturbation theory emerged, a unified perturbative framework for neutrino oscillation in earth matter.
0709.1107
Steven B. Giddings
Steven B. Giddings
High-energy black hole production
Talk at PASCOS 2007, to appear in the proceedings. v2: minor improvements, added refs. v3: reference correction. 11 pages, latex
AIPConf.Proc.957:69-78,2007
10.1063/1.2823829
null
hep-ph gr-qc hep-th
null
Black hole production in high-energy collisions is briefly surveyed. Included is a summary of recent developments and open problems relevant to collider (LHC) production, as well as of some theoretical issues pointing towards fundamental principles of quantum gravity.
[ { "created": "Fri, 7 Sep 2007 16:05:13 GMT", "version": "v1" }, { "created": "Wed, 19 Sep 2007 22:19:06 GMT", "version": "v2" }, { "created": "Fri, 5 Oct 2007 21:08:51 GMT", "version": "v3" } ]
2008-11-26
[ [ "Giddings", "Steven B.", "" ] ]
Black hole production in high-energy collisions is briefly surveyed. Included is a summary of recent developments and open problems relevant to collider (LHC) production, as well as of some theoretical issues pointing towards fundamental principles of quantum gravity.
hep-ph/0509170
Markus Diehl
M. Diehl
On the distribution of partons in the transverse plane
4 pages, 2 figures. Talk given at the International Conference on QCD and Hadronic Physics, Beijing, China, 2005
Int.J.Mod.Phys. A21 (2006) 938-941
10.1142/S0217751X06032368
DESY-05-159
hep-ph
null
Elastic nucleon form factors constrain the spatial distribution of quarks in the impact parameter plane. A recent analysis found that the average impact parameter of quarks strongly depends on their longitudinal momentum, and obtained an estimate of the orbital angular momentum carried by valence quarks in the proton.
[ { "created": "Fri, 16 Sep 2005 13:34:38 GMT", "version": "v1" } ]
2009-11-11
[ [ "Diehl", "M.", "" ] ]
Elastic nucleon form factors constrain the spatial distribution of quarks in the impact parameter plane. A recent analysis found that the average impact parameter of quarks strongly depends on their longitudinal momentum, and obtained an estimate of the orbital angular momentum carried by valence quarks in the proton.
1205.0011
Marco Farina
Marco Farina, Christophe Grojean, Ennio Salvioni
(Dys)Zphilia or a custodial breaking Higgs at the LHC
16 pages, 10 figures
null
10.1007/JHEP07(2012)012
CERN-PH-TH/2012-086
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electroweak precision measurements established that custodial symmetry is preserved to a good accuracy in the gauge sector after electroweak symmetry breaking. However, recent LHC results might be interpreted as pointing towards Higgs couplings that do not respect such symmetry. Motivated by this possibility, we reconsider the presence of an explicitly custodial breaking coupling in a generic Higgs parameterization. After briefly commenting on the large UV sensitivity of the T parameter to such a coupling, we perform a fit to results of Higgs searches at LHC and Tevatron, and find that the apparent enhancement of the ZZ channel with respect to WW can be accommodated. Two degenerate best-fit points are present, which we label `Zphilic' and `dysZphilic' depending on the sign of the hZZ coupling. Finally we highlight some measurements at future linear colliders that may remove such degeneracy.
[ { "created": "Mon, 30 Apr 2012 20:00:04 GMT", "version": "v1" } ]
2015-06-04
[ [ "Farina", "Marco", "" ], [ "Grojean", "Christophe", "" ], [ "Salvioni", "Ennio", "" ] ]
Electroweak precision measurements established that custodial symmetry is preserved to a good accuracy in the gauge sector after electroweak symmetry breaking. However, recent LHC results might be interpreted as pointing towards Higgs couplings that do not respect such symmetry. Motivated by this possibility, we reconsider the presence of an explicitly custodial breaking coupling in a generic Higgs parameterization. After briefly commenting on the large UV sensitivity of the T parameter to such a coupling, we perform a fit to results of Higgs searches at LHC and Tevatron, and find that the apparent enhancement of the ZZ channel with respect to WW can be accommodated. Two degenerate best-fit points are present, which we label `Zphilic' and `dysZphilic' depending on the sign of the hZZ coupling. Finally we highlight some measurements at future linear colliders that may remove such degeneracy.
1806.02489
Jacopo Ferretti
J. Ferretti and E. Santopinto
Threshold corrections of $\chi_{\rm c}(2P)$ and $\chi_{\rm b}(3P)$ states and $J/\psi \rho$ and $J/\psi \omega$ transitions of the $X(3872)$ in a coupled-channel model
null
Phys. Lett. B 789, 550 (2019)
10.1016/j.physletb.2018.12.052
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the masses of $\chi_{\rm c}(2P)$ and $\chi_{\rm b}(3P)$ states with threshold corrections in a coupled-channel model. Here, the meson quarkonium core is augmented by higher Fock components due to pair-creation effects. According to our results, we interpret the resonances characterized by very small threshold corrections, like $\chi_{\rm b}(3P)$'s, as almost pure quarkonia, and those states characterized by non-negligible threshold corrections, like the $X(3872)$, as quarkonium cores plus meson-meson components. We also study the $J/\psi \rho$ and $J/\psi \omega$ hidden-flavor strong decays of the $X(3872)$. The decays are calculated as the dissociation of one of these components ($D^0 \bar D^{0*}$) into a $c \bar c$ state ($J/\psi$) plus a light meson ($\rho$ or $\omega$) in a potential model. In particular, our result for the ratio between the $X(3872) \rightarrow J/\psi \omega$ and $J/\psi \rho$ widths (0.6) is compatible with the present experimental data ($0.8\pm0.3$) within the experimental error.
[ { "created": "Thu, 7 Jun 2018 02:11:50 GMT", "version": "v1" }, { "created": "Thu, 14 Jun 2018 12:40:50 GMT", "version": "v2" }, { "created": "Thu, 21 Jun 2018 16:56:03 GMT", "version": "v3" }, { "created": "Mon, 8 Oct 2018 21:22:47 GMT", "version": "v4" }, { "created": "Sun, 23 Dec 2018 15:44:08 GMT", "version": "v5" }, { "created": "Sat, 19 Jan 2019 15:53:37 GMT", "version": "v6" } ]
2019-01-23
[ [ "Ferretti", "J.", "" ], [ "Santopinto", "E.", "" ] ]
We calculate the masses of $\chi_{\rm c}(2P)$ and $\chi_{\rm b}(3P)$ states with threshold corrections in a coupled-channel model. Here, the meson quarkonium core is augmented by higher Fock components due to pair-creation effects. According to our results, we interpret the resonances characterized by very small threshold corrections, like $\chi_{\rm b}(3P)$'s, as almost pure quarkonia, and those states characterized by non-negligible threshold corrections, like the $X(3872)$, as quarkonium cores plus meson-meson components. We also study the $J/\psi \rho$ and $J/\psi \omega$ hidden-flavor strong decays of the $X(3872)$. The decays are calculated as the dissociation of one of these components ($D^0 \bar D^{0*}$) into a $c \bar c$ state ($J/\psi$) plus a light meson ($\rho$ or $\omega$) in a potential model. In particular, our result for the ratio between the $X(3872) \rightarrow J/\psi \omega$ and $J/\psi \rho$ widths (0.6) is compatible with the present experimental data ($0.8\pm0.3$) within the experimental error.
1712.06784
Toshihiko Ota
Toshihiko Ota
Beyond Standard Neutrino Theory
Proceedings of the 19th International Workshop on Neutrinos from Accelerators (NUFACT 2017). Comments, corrections, and suggestions on references are welcome
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, we will discuss phenomenology of new physics associated with neutrinos, in particular, non-standard neutrino interactions, non-unitarity of the lepton mixing matrix, and secret neutrino interactions mediated by a light field.
[ { "created": "Tue, 19 Dec 2017 05:15:30 GMT", "version": "v1" } ]
2017-12-20
[ [ "Ota", "Toshihiko", "" ] ]
In this talk, we will discuss phenomenology of new physics associated with neutrinos, in particular, non-standard neutrino interactions, non-unitarity of the lepton mixing matrix, and secret neutrino interactions mediated by a light field.
hep-ph/0105066
Ian Low
Adam K. Leibovich, Ian Low, and I. Z. Rothstein
A Comment on the Extractions of V_{ub} from Radiative Decays
10 pages, 3 figures; one figure added, one reference added, expanded discussions
Phys.Lett.B513:83-87,2001
10.1016/S0370-2693(01)00667-0
null
hep-ph hep-ex
null
We present a model independent closed form expression for |V_{ub}|^2/|V_{tb} V_{ts}^*|^2, which includes the resummation of large endpoint logarithms as well as the interference effects from the operators $O_2$ and $O_8$. We demonstrate that the method to extract |V_{ub}| presented by the authors in hep-ph/9909404, and modified in this letter to include interference effects, is not just a refinement of the method introduced in hep-ph/9312311. We also discuss the model dependence of the latter proposal. Furthermore, we show that the resummation is not negligible and that the Landau pole does not introduce any significant uncertainties.
[ { "created": "Mon, 7 May 2001 21:56:38 GMT", "version": "v1" }, { "created": "Thu, 10 May 2001 20:20:25 GMT", "version": "v2" } ]
2014-11-17
[ [ "Leibovich", "Adam K.", "" ], [ "Low", "Ian", "" ], [ "Rothstein", "I. Z.", "" ] ]
We present a model independent closed form expression for |V_{ub}|^2/|V_{tb} V_{ts}^*|^2, which includes the resummation of large endpoint logarithms as well as the interference effects from the operators $O_2$ and $O_8$. We demonstrate that the method to extract |V_{ub}| presented by the authors in hep-ph/9909404, and modified in this letter to include interference effects, is not just a refinement of the method introduced in hep-ph/9312311. We also discuss the model dependence of the latter proposal. Furthermore, we show that the resummation is not negligible and that the Landau pole does not introduce any significant uncertainties.
hep-ph/0501007
Tomo Takahashi
Takeo Moroi, Tomo Takahashi and Yoshikazu Toyoda
Relaxing Constraints on Inflation Models with Curvaton
18 pages, 6 figures
Phys.Rev. D72 (2005) 023502
10.1103/PhysRevD.72.023502
null
hep-ph astro-ph
null
We consider the effects of the curvaton, late-decaying scalar condensation, to observational constraints on inflation models. From current observations of cosmic density fluctuations, severe constraints on some class of inflation models are obtained, in particular, on the chaotic inflation with higher-power monomials, the natural inflation, and the new inflation. We study how the curvaton scenario changes (and relaxes) the constraints on these models.
[ { "created": "Mon, 3 Jan 2005 08:22:12 GMT", "version": "v1" } ]
2009-11-11
[ [ "Moroi", "Takeo", "" ], [ "Takahashi", "Tomo", "" ], [ "Toyoda", "Yoshikazu", "" ] ]
We consider the effects of the curvaton, late-decaying scalar condensation, to observational constraints on inflation models. From current observations of cosmic density fluctuations, severe constraints on some class of inflation models are obtained, in particular, on the chaotic inflation with higher-power monomials, the natural inflation, and the new inflation. We study how the curvaton scenario changes (and relaxes) the constraints on these models.
hep-ph/0203133
Szabolcs Borsanyi
Sz. Borsanyi, A. Patkos, D. Sexty
Goldstone excitations from spinodal instability
10 Latex pages, 8 Figures, version accepted for publication in PRD
Phys.Rev. D66 (2002) 025014
10.1103/PhysRevD.66.025014
null
hep-ph
null
The squared mass of a complex scalar field is turned dynamically into negative by its O(2)-invariant coupling to a real field slowly rolling down in a quadratic potential. The emergence of gapless excitations is studied in real time simulations after spinodal instability occurs. Careful tests demonstrate that the Goldstone modes appear almost instantly after the symmetry breaking is over, much before thermal equilibrium is established.
[ { "created": "Thu, 14 Mar 2002 13:19:54 GMT", "version": "v1" }, { "created": "Sun, 12 May 2002 21:03:56 GMT", "version": "v2" } ]
2009-11-07
[ [ "Borsanyi", "Sz.", "" ], [ "Patkos", "A.", "" ], [ "Sexty", "D.", "" ] ]
The squared mass of a complex scalar field is turned dynamically into negative by its O(2)-invariant coupling to a real field slowly rolling down in a quadratic potential. The emergence of gapless excitations is studied in real time simulations after spinodal instability occurs. Careful tests demonstrate that the Goldstone modes appear almost instantly after the symmetry breaking is over, much before thermal equilibrium is established.
hep-ph/9702242
Willy van Neerven
M.Buza, W.L.van Neerven
Order \alpha_s^2 Contributions to charm production in charged-current deep-inelastic lepton-hadron scattering
45 pages LaTeX, 17 Postscript Figures
Nucl.Phys. B500 (1997) 301-324
10.1016/S0550-3213(97)00327-1
null
hep-ph
null
The most important part of the order $\alpha_s^2$ corrections to the charm component of the charged-current structure functions $F_2(x,Q^2)$ and $F_3(x,Q^2)$ have been calculated. This calculation is based on the asymptotic form of the heavy-quark coefficient functions corresponding to the higher order corrections to the W-boson-gluon fusion process. These coefficient functions which are in principle only valid for $Q^2 \gg m^2$ can be also used to estimate the order $\alpha_s^2$ contributions at lower $Q^2$ values provided $x < 0.1$. It turns out that the above corrections are appreciable in the large $Q^2$-region and they explain the discrepancy found for the structure functions between the fixed-flavour scheme (FFS) and the variable-flavour-number scheme (VFNS). These corrections also hamper the extraction of the strange-quark density from the data obtained for the charged-current and the electromagnetic-current processes.
[ { "created": "Tue, 4 Feb 1997 10:49:23 GMT", "version": "v1" } ]
2009-10-30
[ [ "Buza", "M.", "" ], [ "van Neerven", "W. L.", "" ] ]
The most important part of the order $\alpha_s^2$ corrections to the charm component of the charged-current structure functions $F_2(x,Q^2)$ and $F_3(x,Q^2)$ have been calculated. This calculation is based on the asymptotic form of the heavy-quark coefficient functions corresponding to the higher order corrections to the W-boson-gluon fusion process. These coefficient functions which are in principle only valid for $Q^2 \gg m^2$ can be also used to estimate the order $\alpha_s^2$ contributions at lower $Q^2$ values provided $x < 0.1$. It turns out that the above corrections are appreciable in the large $Q^2$-region and they explain the discrepancy found for the structure functions between the fixed-flavour scheme (FFS) and the variable-flavour-number scheme (VFNS). These corrections also hamper the extraction of the strange-quark density from the data obtained for the charged-current and the electromagnetic-current processes.
1312.1363
Itay Yavin
Maxim Pospelov, Neal Weiner, and Itay Yavin
Dark matter detection in two easy steps
14 pages, 14 figures
Phys. Rev. D 89, 055008 (2014)
10.1103/PhysRevD.89.055008
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multi-component dark matter particles may have a more intricate direct detection signal than simple elastic scattering on nuclei. In a broad class of well-motivated models the inelastic excitation of dark matter particles is followed by de-excitation via $\gamma$-decay. In experiments with fine energy resolution, such as many $0\nu 2\beta$ decay experiments, this motivates a highly model-independent search for the sidereal daily modulation of an unexpected $\gamma$ line. Such a signal arises from two-step WIMP interaction: the WIMP is first excited in the lead shielding and subsequently decays back to the ground state via the emission of a monochromatic $\gamma$ within the detector volume. We explore this idea in detail by considering the model of magnetic inelastic WIMPs, and take a sequence of CUORE-type detectors as an example. We find that under reasonable assumptions about detector performance it is possible to efficiently explore mass splittings of up to few hundreds of keV for a WIMP of weak-scale mass and transitional magnetic moments. The modulation can be cheaply and easily enhanced by the presence of additional asymmetric lead shielding. We devise a toy simulation to show that a specially designed asymmetric shielding may result in up to $30\%$ diurnal modulations of the two-step WIMP signal, leading to additional strong gains in sensitivity.
[ { "created": "Wed, 4 Dec 2013 21:34:03 GMT", "version": "v1" } ]
2014-03-19
[ [ "Pospelov", "Maxim", "" ], [ "Weiner", "Neal", "" ], [ "Yavin", "Itay", "" ] ]
Multi-component dark matter particles may have a more intricate direct detection signal than simple elastic scattering on nuclei. In a broad class of well-motivated models the inelastic excitation of dark matter particles is followed by de-excitation via $\gamma$-decay. In experiments with fine energy resolution, such as many $0\nu 2\beta$ decay experiments, this motivates a highly model-independent search for the sidereal daily modulation of an unexpected $\gamma$ line. Such a signal arises from two-step WIMP interaction: the WIMP is first excited in the lead shielding and subsequently decays back to the ground state via the emission of a monochromatic $\gamma$ within the detector volume. We explore this idea in detail by considering the model of magnetic inelastic WIMPs, and take a sequence of CUORE-type detectors as an example. We find that under reasonable assumptions about detector performance it is possible to efficiently explore mass splittings of up to few hundreds of keV for a WIMP of weak-scale mass and transitional magnetic moments. The modulation can be cheaply and easily enhanced by the presence of additional asymmetric lead shielding. We devise a toy simulation to show that a specially designed asymmetric shielding may result in up to $30\%$ diurnal modulations of the two-step WIMP signal, leading to additional strong gains in sensitivity.
1903.08137
Gudrun Heinrich
G.Heinrich, S.P.Jones, M.Kerner, G.Luisoni, L.Scyboz
Probing the trilinear Higgs boson coupling in di-Higgs production at NLO QCD including parton shower effects
20 pages, 7 figures; v2: matches published version
J. High Energ. Phys. (2019) 66
10.1007/JHEP06(2019)066
CERN-TH-2019-028, MPP-2019-50, ZU-TH-09/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results for Higgs boson pair production with variations of the trilinear Higgs boson self-coupling at next-to-leading order (NLO) in QCD including the full top quark mass dependence. Differential results at 14 TeV are presented, and we discuss the implications of anomalous trilinear couplings as well as differences between the PYTHIA 8.2 and HERWIG 7.1 parton showers in combination with POWHEG. The implementation of the NLO QCD calculation with variable Higgs boson self-coupling is made publicly available in the POWHEG-BOX-V2 Monte Carlo framework. A simple method for using the new implementation to study also variations of the top quark Yukawa coupling is described.
[ { "created": "Tue, 19 Mar 2019 17:48:02 GMT", "version": "v1" }, { "created": "Mon, 24 Jun 2019 17:28:52 GMT", "version": "v2" } ]
2019-06-25
[ [ "Heinrich", "G.", "" ], [ "Jones", "S. P.", "" ], [ "Kerner", "M.", "" ], [ "Luisoni", "G.", "" ], [ "Scyboz", "L.", "" ] ]
We present results for Higgs boson pair production with variations of the trilinear Higgs boson self-coupling at next-to-leading order (NLO) in QCD including the full top quark mass dependence. Differential results at 14 TeV are presented, and we discuss the implications of anomalous trilinear couplings as well as differences between the PYTHIA 8.2 and HERWIG 7.1 parton showers in combination with POWHEG. The implementation of the NLO QCD calculation with variable Higgs boson self-coupling is made publicly available in the POWHEG-BOX-V2 Monte Carlo framework. A simple method for using the new implementation to study also variations of the top quark Yukawa coupling is described.
1611.05017
Mohammadreza Zakeri
Corey Kownacki, Ernest Ma, Nicholas Pollard, and Mohammadreza Zakeri
Generalized Gauge U(1) Family Symmetry for Quarks and Leptons
13 pages
null
10.1016/j.physletb.2017.01.013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If the standard model of quarks and leptons is extended to include three singlet right-handed neutrinos, then the resulting fermion structure admits an infinite number of anomaly-free solutions with just one simple constraint. Well-known examples satisfying this constraint are $B-L$, $L_{\mu}-L_{\tau}$ , $B-3L_{\tau}$ , etc. We derive this simple constraint, and discuss two new examples which offer some insights to the structure of mixing among quark and lepton families, together with their possible verification at the Large Hadron Collider.
[ { "created": "Tue, 15 Nov 2016 20:25:45 GMT", "version": "v1" }, { "created": "Wed, 23 Nov 2016 19:41:25 GMT", "version": "v2" } ]
2017-01-18
[ [ "Kownacki", "Corey", "" ], [ "Ma", "Ernest", "" ], [ "Pollard", "Nicholas", "" ], [ "Zakeri", "Mohammadreza", "" ] ]
If the standard model of quarks and leptons is extended to include three singlet right-handed neutrinos, then the resulting fermion structure admits an infinite number of anomaly-free solutions with just one simple constraint. Well-known examples satisfying this constraint are $B-L$, $L_{\mu}-L_{\tau}$ , $B-3L_{\tau}$ , etc. We derive this simple constraint, and discuss two new examples which offer some insights to the structure of mixing among quark and lepton families, together with their possible verification at the Large Hadron Collider.
1110.1330
John W. Moffat
J. W. Moffat
Bimetric Relativity and the Opera Neutrino Experiment
6 pages, 1 figure, typo corrected. Minor corrections
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility of explaining the propagation of neutrinos measured by the OPERA experiment with $\delta v_\nu=(v_\nu-c_0)/c_0$, where $c_0$ is the speed of light in vacuum, using a bimetric relativity model. The geometry of the bimetric model has two metrics in spacetime. One metric $g_{\mu\nu}$ possesses a null cone along which massless gravitons and photons travel with the constant speed $c_0$, while the other `matter' metric ${\hat g}_{\mu\nu}=g_{\mu\nu}+\beta\psi_\mu\psi_\nu$ has a null cone with a bigger speed $c > c_0$ with $0 < \delta v_\nu\ll c/c_0$. This second cone structure of spacetime prevents the neutrinos from being superluminal tachyons $v_\nu < c$. Such superluminal neutrinos would lead to severe depletion of neutrino energy, refuting the OPERA result. The charge-current source of the background gauge field $\psi_\mu$ is assumed to be baryon charge and the strength of the field $\psi_\mu$ is distance dependent, explaining the observation that for supernova SN1987a $v_\nu\simeq c_0$. Altering the path of the neutrinos through the earth or performing a space experiment can test the OPERA neutrino experimental result.
[ { "created": "Thu, 6 Oct 2011 17:30:38 GMT", "version": "v1" }, { "created": "Fri, 7 Oct 2011 19:36:39 GMT", "version": "v2" }, { "created": "Wed, 12 Oct 2011 18:57:40 GMT", "version": "v3" } ]
2011-10-13
[ [ "Moffat", "J. W.", "" ] ]
We investigate the possibility of explaining the propagation of neutrinos measured by the OPERA experiment with $\delta v_\nu=(v_\nu-c_0)/c_0$, where $c_0$ is the speed of light in vacuum, using a bimetric relativity model. The geometry of the bimetric model has two metrics in spacetime. One metric $g_{\mu\nu}$ possesses a null cone along which massless gravitons and photons travel with the constant speed $c_0$, while the other `matter' metric ${\hat g}_{\mu\nu}=g_{\mu\nu}+\beta\psi_\mu\psi_\nu$ has a null cone with a bigger speed $c > c_0$ with $0 < \delta v_\nu\ll c/c_0$. This second cone structure of spacetime prevents the neutrinos from being superluminal tachyons $v_\nu < c$. Such superluminal neutrinos would lead to severe depletion of neutrino energy, refuting the OPERA result. The charge-current source of the background gauge field $\psi_\mu$ is assumed to be baryon charge and the strength of the field $\psi_\mu$ is distance dependent, explaining the observation that for supernova SN1987a $v_\nu\simeq c_0$. Altering the path of the neutrinos through the earth or performing a space experiment can test the OPERA neutrino experimental result.
1510.07319
Andrew Fowlie Dr.
Andrew Fowlie
LHCO_reader: A new code for reading and analyzing detector-level events stored in LHCO format
28 pages, new features of code described, including alpha_T, razor and mT2
null
null
CoEPP-MN-15-10
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new Python module - LHCO_reader - for reading detector-level events in LHCO format generated from detector-simulators such as PGS and Delphes. Emphasis is placed upon ease of use. The module is installed via pip. Once installed, one can read and scrutinize events, with helpful functions and classes for cutting, plotting and inspecting events, and manipulating four-momenta by e.g. boosting. Implementing complicated analyses should be straight-forward by coding any cuts into Python. Furthermore, common kinematic variables, including $\alpha_T$ and razor are included out of the box, and $m_{T2}$ and $m_{T2}^W$ are provided by interfaces with external libraries.
[ { "created": "Sun, 25 Oct 2015 22:52:41 GMT", "version": "v1" }, { "created": "Tue, 23 Feb 2016 23:50:20 GMT", "version": "v2" } ]
2016-02-25
[ [ "Fowlie", "Andrew", "" ] ]
We present a new Python module - LHCO_reader - for reading detector-level events in LHCO format generated from detector-simulators such as PGS and Delphes. Emphasis is placed upon ease of use. The module is installed via pip. Once installed, one can read and scrutinize events, with helpful functions and classes for cutting, plotting and inspecting events, and manipulating four-momenta by e.g. boosting. Implementing complicated analyses should be straight-forward by coding any cuts into Python. Furthermore, common kinematic variables, including $\alpha_T$ and razor are included out of the box, and $m_{T2}$ and $m_{T2}^W$ are provided by interfaces with external libraries.
1505.00550
Alka Upadhyay
A. Upadhyay, M. Batra
Importance of Non-Perturbative QCD Parameters for Bottom Mesons
Volume 2014 (2014), Article ID 619783, 4 pages, Advances in High Energy Physics, 2014. arXiv admin note: text overlap with arXiv:1312.5406
Advances in High Energy Physics, 2014,Volume 2014, Article ID 619783, 4 pages
10.1155/2014/619783
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The importance of non-perturbative Quantum Chromodynamics [QCD] parameters is discussed in context to the predicting power for bottom meson masses and isospin splitting. In the framework of heavy quark effective theory, the work presented here focuses on the different allowed values of the two non perturbative QCD parameters used in heavy quark effective theory formula and using the best fitted parameter, masses of the excited bottom meson states in JP=(1/2)+ doublet in strange as well as non-strange sector are calculated here. The calculated masses are found to be matching well with experiments and other phenomenological models. The mass and hyperfine splitting has also been analyzed for both strange and non-strange heavy mesons with respect to spin and flavor symmetries.
[ { "created": "Mon, 4 May 2015 08:20:04 GMT", "version": "v1" } ]
2016-05-13
[ [ "Upadhyay", "A.", "" ], [ "Batra", "M.", "" ] ]
The importance of non-perturbative Quantum Chromodynamics [QCD] parameters is discussed in context to the predicting power for bottom meson masses and isospin splitting. In the framework of heavy quark effective theory, the work presented here focuses on the different allowed values of the two non perturbative QCD parameters used in heavy quark effective theory formula and using the best fitted parameter, masses of the excited bottom meson states in JP=(1/2)+ doublet in strange as well as non-strange sector are calculated here. The calculated masses are found to be matching well with experiments and other phenomenological models. The mass and hyperfine splitting has also been analyzed for both strange and non-strange heavy mesons with respect to spin and flavor symmetries.
hep-ph/9211309
Mariano Quiros
I. Antoniadis, C. Mu\~noz and M. Quir\'os
Dynamical supersymmetry breaking with a large internal dimension
27 pages, latex, 6 figures available by FAX upon request
Nucl.Phys. B397 (1993) 515-538
10.1016/0550-3213(93)90184-Q
CPTH-A206.1192, FTUAM 92/35, IEM-FT-63/92
hep-ph hep-th
null
Supersymmetry breaking in string perturbation theory predicts the existence of a new dimension at the TeV scale. The simplest realization of the minimal supersymmetric Standard Model in the context of this mechanism has two important consequences: (i) A natural solution to the $\mu$-problem; (ii) The absence of quadratic divergences in the cosmological constant, which leads to a dynamical determination of the supersymmetry breaking and electroweak scale. We present an explicit example in which the whole particle spectrum is given as a function of the top quark mass. A generic prediction of this mechanism is the existence of Kaluza-Klein excitations for gauge bosons and higgses. In particular the first excitation of the photon could be accessible to future accelerators and give a clear signal of the proposed mechanism.
[ { "created": "Wed, 25 Nov 1992 17:24:54 GMT", "version": "v1" } ]
2009-10-22
[ [ "Antoniadis", "I.", "" ], [ "Muñoz", "C.", "" ], [ "Quirós", "M.", "" ] ]
Supersymmetry breaking in string perturbation theory predicts the existence of a new dimension at the TeV scale. The simplest realization of the minimal supersymmetric Standard Model in the context of this mechanism has two important consequences: (i) A natural solution to the $\mu$-problem; (ii) The absence of quadratic divergences in the cosmological constant, which leads to a dynamical determination of the supersymmetry breaking and electroweak scale. We present an explicit example in which the whole particle spectrum is given as a function of the top quark mass. A generic prediction of this mechanism is the existence of Kaluza-Klein excitations for gauge bosons and higgses. In particular the first excitation of the photon could be accessible to future accelerators and give a clear signal of the proposed mechanism.
2112.10337
Atsushi Hinata
A. Hinata
Seesaw mechanism in the R-parity violating supersymmetric standard model with the gauged flavor $\mathrm{U}(1)_X$ symmetry
36 pages, 2 figures. Updated to the revised version with added the phenomenological discussion and figures
null
null
WU-HEP-21-06
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the seesaw mechanism in the supersymmetric standard model (SSM) with ${\mathbb Z}_3$ symmetry instead of the R-parity, so-called {\it Matter triality} ($M_3$). This Abelian discrete symmetry prohibits the baryon/lepton number violation operators at the non-renormalizable level, and the proton longevity is ensured. The lepton number violation term by the right-handed neutrino is only allowed under the symmetry, it plays a role of the Majorana mass after the right-handed sneutrino develops into the vacuum expectation value. The mass of the active neutrino is generated from the two contributions from the right-handed neutrino and the neutralino due to the R-parity violation. In this paper, we realize the neutrino mass and mixing angle in the SSM with matter triality which is embedded into the gauged flavor ${\mathrm{U}}(1)_X$ symmetry. In addition to the flavor ansatz, we derive the charge assignment to satisfy the anomaly cancellation conditions. Then, the model could predict the sterile neutrino with the mass below the soft SUSY breaking mass scale, and its mass and mixing angle are restricted by the search for the heavy neutral leptons.
[ { "created": "Mon, 20 Dec 2021 04:54:10 GMT", "version": "v1" }, { "created": "Tue, 29 Mar 2022 04:08:03 GMT", "version": "v2" } ]
2022-03-30
[ [ "Hinata", "A.", "" ] ]
We study the seesaw mechanism in the supersymmetric standard model (SSM) with ${\mathbb Z}_3$ symmetry instead of the R-parity, so-called {\it Matter triality} ($M_3$). This Abelian discrete symmetry prohibits the baryon/lepton number violation operators at the non-renormalizable level, and the proton longevity is ensured. The lepton number violation term by the right-handed neutrino is only allowed under the symmetry, it plays a role of the Majorana mass after the right-handed sneutrino develops into the vacuum expectation value. The mass of the active neutrino is generated from the two contributions from the right-handed neutrino and the neutralino due to the R-parity violation. In this paper, we realize the neutrino mass and mixing angle in the SSM with matter triality which is embedded into the gauged flavor ${\mathrm{U}}(1)_X$ symmetry. In addition to the flavor ansatz, we derive the charge assignment to satisfy the anomaly cancellation conditions. Then, the model could predict the sterile neutrino with the mass below the soft SUSY breaking mass scale, and its mass and mixing angle are restricted by the search for the heavy neutral leptons.
hep-ph/0105001
Masahide Yamaguchi
Masahide Yamaguchi
Density Fluctuations and Primordial Black Hole Formation in Natural Double Inflation in Supergravity
21 pages, 2 figures, to appear in Phys. Rev. D
Phys.Rev. D64 (2001) 063503
10.1103/PhysRevD.64.063503
null
hep-ph astro-ph
null
We investigate the recently proposed natural double inflation model in supergravity. Chaotic inflation first takes place by virtue of the Nambu-Goldstone-like shift symmetry. During chaotic inflation, an initial value of second inflation (new inflation) is set, which is adequately far from the local maximum of the potential due to the small linear term in the K\"ahler potential. Then, primordial fluctuations within the present horizon scale may be produced during both inflations. Primordial fluctuations responsible for anisotropies of the cosmic microwave background radiation and the large scale structure are produced during chaotic inflation, while fluctuations on smaller scales are produced during new inflation. Because of the peculiar nature of new inflation, they can become as large as $10^{-1}$-$10^{-2}$, which may lead to the formation of primordial black holes.
[ { "created": "Tue, 1 May 2001 03:15:09 GMT", "version": "v1" }, { "created": "Fri, 13 Jul 2001 05:34:33 GMT", "version": "v2" } ]
2009-11-07
[ [ "Yamaguchi", "Masahide", "" ] ]
We investigate the recently proposed natural double inflation model in supergravity. Chaotic inflation first takes place by virtue of the Nambu-Goldstone-like shift symmetry. During chaotic inflation, an initial value of second inflation (new inflation) is set, which is adequately far from the local maximum of the potential due to the small linear term in the K\"ahler potential. Then, primordial fluctuations within the present horizon scale may be produced during both inflations. Primordial fluctuations responsible for anisotropies of the cosmic microwave background radiation and the large scale structure are produced during chaotic inflation, while fluctuations on smaller scales are produced during new inflation. Because of the peculiar nature of new inflation, they can become as large as $10^{-1}$-$10^{-2}$, which may lead to the formation of primordial black holes.
hep-ph/0111447
A. I. Milstein
R.N.Lee, A.L.Maslennikov, A.I.Milstein, V.M.Strakhovenko, and Yu.A.Tikhonov
Photon splitting in atomic fields
45 pages, 24 figures
Phys.Rept.373:213,2003
10.1016/S0370-1573(02)00030-3
null
hep-ph
null
Photon splitting due to vacuum polarization in the electric field of an atom is considered. We survey different theoretical approaches to the description of this nonlinear QED process and several attempts of its experimental observation. We present the results of the lowest-order perturbation theory as well as those obtained within the quasiclassical approximation being exact in the external field strength. The experiment where photon splitting was really observed for the first time is discussed in details. The results of this experiment are compared with recent theoretical estimations.
[ { "created": "Fri, 30 Nov 2001 06:20:27 GMT", "version": "v1" } ]
2009-11-07
[ [ "Lee", "R. N.", "" ], [ "Maslennikov", "A. L.", "" ], [ "Milstein", "A. I.", "" ], [ "Strakhovenko", "V. M.", "" ], [ "Tikhonov", "Yu. A.", "" ] ]
Photon splitting due to vacuum polarization in the electric field of an atom is considered. We survey different theoretical approaches to the description of this nonlinear QED process and several attempts of its experimental observation. We present the results of the lowest-order perturbation theory as well as those obtained within the quasiclassical approximation being exact in the external field strength. The experiment where photon splitting was really observed for the first time is discussed in details. The results of this experiment are compared with recent theoretical estimations.
2408.01488
Sudip Jana
Sudip Jana, Lucas Puetter, Alexei Yu. Smirnov
Restricting Sterile Neutrinos by Neutrinoless Double Beta Decay
6 pages + references, 4 figures
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The bounds on parameters of the eV and higher scale sterile neutrinos from the $0\nu \beta \beta$ decay have been refined and updated. We present a simple and compact analytic expression for the bound in the $\Delta m^2_{41} - \sin^2 2\theta_{14}$ plane, which includes all relevant parameters. Dependencies of the bound on unknown CP-phases and the type of mass spectrum of light neutrinos (mass ordering and level of degeneracy) are studied in detail. We have computed the bounds using the latest and most stringent data from KamLAND-Zen. The projected constraints from future experiments are estimated. The obtained bounds are confronted with positive indications of the presence of sterile neutrinos as well as with the other existing bounds. The $0\nu \beta \beta$ decay results exclude the regions of parameters implied by BEST and Neutrino-4, and the regions indicated by LSND and MiniBooNE are in conflict with $0\nu \beta \beta$ results combined with $\nu_\mu-$ disappearance bounds.
[ { "created": "Fri, 2 Aug 2024 18:00:00 GMT", "version": "v1" } ]
2024-08-07
[ [ "Jana", "Sudip", "" ], [ "Puetter", "Lucas", "" ], [ "Smirnov", "Alexei Yu.", "" ] ]
The bounds on parameters of the eV and higher scale sterile neutrinos from the $0\nu \beta \beta$ decay have been refined and updated. We present a simple and compact analytic expression for the bound in the $\Delta m^2_{41} - \sin^2 2\theta_{14}$ plane, which includes all relevant parameters. Dependencies of the bound on unknown CP-phases and the type of mass spectrum of light neutrinos (mass ordering and level of degeneracy) are studied in detail. We have computed the bounds using the latest and most stringent data from KamLAND-Zen. The projected constraints from future experiments are estimated. The obtained bounds are confronted with positive indications of the presence of sterile neutrinos as well as with the other existing bounds. The $0\nu \beta \beta$ decay results exclude the regions of parameters implied by BEST and Neutrino-4, and the regions indicated by LSND and MiniBooNE are in conflict with $0\nu \beta \beta$ results combined with $\nu_\mu-$ disappearance bounds.
1702.01189
Richard Hill
Richard J. Hill
Review of experimental and theoretical status of the proton radius puzzle
22 pages, 14 figures, invited plenary talk presented at XII Quark Confinement and the Hadron Spectrum, Thessaloniki, 2016
null
10.1051/epjconf/201713701023
null
hep-ph nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discrepancy between the measured Lamb shift in muonic hydrogen and expectations from electron-proton scattering and regular hydrogen spectroscopy has become known as the proton radius puzzle, whose most "mundane" resolution requires a $> 5 \sigma$ shift in the value of the fundamental Rydberg constant. I briefly review the status of spectroscopic and scattering measurements, recent theoretical developments, and implications for fundamental physics.
[ { "created": "Fri, 3 Feb 2017 22:13:51 GMT", "version": "v1" } ]
2017-04-05
[ [ "Hill", "Richard J.", "" ] ]
The discrepancy between the measured Lamb shift in muonic hydrogen and expectations from electron-proton scattering and regular hydrogen spectroscopy has become known as the proton radius puzzle, whose most "mundane" resolution requires a $> 5 \sigma$ shift in the value of the fundamental Rydberg constant. I briefly review the status of spectroscopic and scattering measurements, recent theoretical developments, and implications for fundamental physics.
hep-ph/0012160
Richard F. Lebed
Xiangdong Ji and Richard F. Lebed
Counting Form Factors of Twist-Two Operators
7 pages, LaTeX (revtex)
Phys.Rev. D63 (2001) 076005
10.1103/PhysRevD.63.076005
UMD PP#01-030, DOE/ER/40762-216
hep-ph nucl-th
null
We present a simple method to count the number of hadronic form factors based on the partial wave formalism and crossing symmetry. In particular, we show that the number of independent nucleon form factors of spin-n, twist-2 operators (the vector current and energy-momentum tensor being special examples) is n+1. These generalized form factors define the generalized (off-forward) parton distributions that have been studied extensively in the recent literature. In proving this result, we also show how the J^{PC} rules for onium states arise in the helicity formalism.
[ { "created": "Wed, 13 Dec 2000 20:57:32 GMT", "version": "v1" } ]
2009-10-31
[ [ "Ji", "Xiangdong", "" ], [ "Lebed", "Richard F.", "" ] ]
We present a simple method to count the number of hadronic form factors based on the partial wave formalism and crossing symmetry. In particular, we show that the number of independent nucleon form factors of spin-n, twist-2 operators (the vector current and energy-momentum tensor being special examples) is n+1. These generalized form factors define the generalized (off-forward) parton distributions that have been studied extensively in the recent literature. In proving this result, we also show how the J^{PC} rules for onium states arise in the helicity formalism.
1507.01130
Yazid Delenda
Yazid Delenda, Kamel Khelifa-Kerfa
On the resummation of non-global logarithms at finite $\mathbf{N_c}$
To appear in the proceedings of the XXIII International Workshop on Deep-Inelastic Scattering and Related Subjects, April 27 - May 1, 2015, Dallas, Texas, USA
PoS(DIS2015)138
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a calculation of non-global logs at finite $\mathrm{N_c}$ for the hemisphere mass distribution in $e^+e^-\to 2$ jets at single log accuracy up to fifth order in the strong coupling constant. Our results suggest a possible all-orders resummation of these large logs into an exponential. Comparing our results to those at large $\mathrm{N_c}$, recently reported in literature, we find an agreement. We additionally compare our findings with the numerical all-orders resummation at large $\mathrm{N_c}$ and discuss the significance of neglected finite-$\mathrm{N_c}$ corrections on the said distribution.
[ { "created": "Sat, 4 Jul 2015 17:33:59 GMT", "version": "v1" } ]
2015-07-07
[ [ "Delenda", "Yazid", "" ], [ "Khelifa-Kerfa", "Kamel", "" ] ]
We present a calculation of non-global logs at finite $\mathrm{N_c}$ for the hemisphere mass distribution in $e^+e^-\to 2$ jets at single log accuracy up to fifth order in the strong coupling constant. Our results suggest a possible all-orders resummation of these large logs into an exponential. Comparing our results to those at large $\mathrm{N_c}$, recently reported in literature, we find an agreement. We additionally compare our findings with the numerical all-orders resummation at large $\mathrm{N_c}$ and discuss the significance of neglected finite-$\mathrm{N_c}$ corrections on the said distribution.
1411.7040
Pier Paolo Giardino
Giuseppe Degrassi, Paolo Gambino and Pier Paolo Giardino
The $m_{\scriptscriptstyle W}-m_{\scriptscriptstyle Z}$ interdependence in the Standard Model: a new scrutiny
21 pages, 1 figure
null
null
RM3-TH/14-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $m_{\scriptscriptstyle W}-m_{\scriptscriptstyle Z}$ interdependence in the Standard Model is studied at $O(\alpha^2) $ in the $\overline{MS}$ scheme. The relevant radiative parameters, $\Delta \hat{\alpha} (\mu),\, \Delta \hat{r}_{W},\, \hat{\rho}$ are computed at the full two-loop level augmented by higher-order QCD contributions and by resummation of reducible contributions. We obtain $m_{\scriptscriptstyle W} = 80.357 \pm 0.009 \pm 0.003$ GeV where the errors refer to the parametric and theoretical uncertainties, respectively. A comparison with the known result in the On-Shell scheme gives a difference of $ \approx 6$ MeV. As a byproduct of our calculation we also obtain the $\overline{MS}$ electromagnetic coupling and the Weinberg angle at the top mass scale, $\hat{\alpha} (M_t) = (127.73)^{-1} \pm 0.0000003$ and $\sin^{2}\!\hat{\theta}_{W} (M_t) = 0.23462 \pm 0.00012$.
[ { "created": "Tue, 25 Nov 2014 21:00:39 GMT", "version": "v1" } ]
2014-11-28
[ [ "Degrassi", "Giuseppe", "" ], [ "Gambino", "Paolo", "" ], [ "Giardino", "Pier Paolo", "" ] ]
The $m_{\scriptscriptstyle W}-m_{\scriptscriptstyle Z}$ interdependence in the Standard Model is studied at $O(\alpha^2) $ in the $\overline{MS}$ scheme. The relevant radiative parameters, $\Delta \hat{\alpha} (\mu),\, \Delta \hat{r}_{W},\, \hat{\rho}$ are computed at the full two-loop level augmented by higher-order QCD contributions and by resummation of reducible contributions. We obtain $m_{\scriptscriptstyle W} = 80.357 \pm 0.009 \pm 0.003$ GeV where the errors refer to the parametric and theoretical uncertainties, respectively. A comparison with the known result in the On-Shell scheme gives a difference of $ \approx 6$ MeV. As a byproduct of our calculation we also obtain the $\overline{MS}$ electromagnetic coupling and the Weinberg angle at the top mass scale, $\hat{\alpha} (M_t) = (127.73)^{-1} \pm 0.0000003$ and $\sin^{2}\!\hat{\theta}_{W} (M_t) = 0.23462 \pm 0.00012$.
1602.00923
Treleani Daniele
Daniele Treleani and Giorgio Calucci
A Brief Comment on Multi-Gluon Amplitudes and Double Parton Interactions
5 pages, 5 figures. Prepared for the MPI@LHC2015, ICTP Trieste, Italy
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A typical contribution to a color ordered multi-gluon amplitude, which can split into two weakly correlated two-body gluon scattering amplitudes and may thus contribute to a Double Parton Interaction, is briefly discussed. We find that the color ordered amplitude is not enhanced in the typical configuration generated by a DPI, where the transverse momenta of final state gluons are compensated pairwise, while a dominant contribution to the multi-gluon amplitude is due to terms proportional to the fusion amplitude of two initial state gluons. Which corresponds to an amplitude effectively describing a two rather than a three-body partonic interaction.
[ { "created": "Tue, 2 Feb 2016 13:52:14 GMT", "version": "v1" } ]
2016-02-03
[ [ "Treleani", "Daniele", "" ], [ "Calucci", "Giorgio", "" ] ]
A typical contribution to a color ordered multi-gluon amplitude, which can split into two weakly correlated two-body gluon scattering amplitudes and may thus contribute to a Double Parton Interaction, is briefly discussed. We find that the color ordered amplitude is not enhanced in the typical configuration generated by a DPI, where the transverse momenta of final state gluons are compensated pairwise, while a dominant contribution to the multi-gluon amplitude is due to terms proportional to the fusion amplitude of two initial state gluons. Which corresponds to an amplitude effectively describing a two rather than a three-body partonic interaction.
hep-ph/0410399
Mike Whalley
M. R. Whalley
A New Neutrino Cross Section Database
6 pages, 3 figures, To appear in the proceedings of the 3rd International Workshop on Neutrino Nucleus Interactions in the few GeV region (NuInt04), Gran Sasso, Assergi, Italy, 17-21 Mar 2004
null
10.1016/j.nuclphysbps.2004.11.216
null
hep-ph
null
We describe a new web based data resource being developed to provide access to accurate and validated cross sections of low energy neutrino and antineutrino interactions. The proposed content of this database are outlined which cover total and differential cross from inclusive, quasi-elastic and exclusive pion production processes from charged and neutral current interactions. Efforts to obtain these data, which come mainly from old bubble chamber experiments, are described as well as the implementation of an embryonic web site to make the resource generally accessible.
[ { "created": "Fri, 29 Oct 2004 09:37:24 GMT", "version": "v1" } ]
2009-11-10
[ [ "Whalley", "M. R.", "" ] ]
We describe a new web based data resource being developed to provide access to accurate and validated cross sections of low energy neutrino and antineutrino interactions. The proposed content of this database are outlined which cover total and differential cross from inclusive, quasi-elastic and exclusive pion production processes from charged and neutral current interactions. Efforts to obtain these data, which come mainly from old bubble chamber experiments, are described as well as the implementation of an embryonic web site to make the resource generally accessible.
hep-ph/9508354
Ulf Meissner
B. Borasoy and Ulf-G. Mei{\ss}ner
Baryon masses and pion-nucleon $\sigma$-term to second order in the quark masses
11 pp, LaTeX, uses elsart.sty+elsart12.sty, fig. in separate file
Phys.Lett. B365 (1996) 285-291
10.1016/0370-2693(95)01286-9
TK 95 21
hep-ph nucl-th
null
We analyze the octet baryon masses and the pion--nucleon $\sigma$--term in the framework of heavy baryon chiral perturbation theory. In contrast to previous investigations, we include {\it all} terms up-to-and-including quadratic order in the light quark masses. The pertinent low--energy constants are fixed from resonance exchange. This leaves as the only free parameter the baryon mass in the chiral limit, $\krig{m}$. We find $\krig{m} = 749 \pm 125$~MeV together with $\sigma_{\pi N} (0) = 48 \pm 10$ ~MeV. We discuss various implications of these results.
[ { "created": "Wed, 23 Aug 1995 14:06:06 GMT", "version": "v1" }, { "created": "Thu, 24 Aug 1995 07:33:09 GMT", "version": "v2" } ]
2009-10-28
[ [ "Borasoy", "B.", "" ], [ "Meißner", "Ulf-G.", "" ] ]
We analyze the octet baryon masses and the pion--nucleon $\sigma$--term in the framework of heavy baryon chiral perturbation theory. In contrast to previous investigations, we include {\it all} terms up-to-and-including quadratic order in the light quark masses. The pertinent low--energy constants are fixed from resonance exchange. This leaves as the only free parameter the baryon mass in the chiral limit, $\krig{m}$. We find $\krig{m} = 749 \pm 125$~MeV together with $\sigma_{\pi N} (0) = 48 \pm 10$ ~MeV. We discuss various implications of these results.
hep-ph/9211305
Francesca Borzumati
F.M. Borzumati, B.A. Kniehl, G. Kramer
Higher-Order QCD Corrections to Inclusive Particle Production in p anti-p Collisions
28 pages, [12 uuencoded PS figures, 3 available under request]. Preprint DESY 92-135
Z.Phys. C57 (1993) 595-604
10.1007/BF01561478
null
hep-ph
null
Inclusive single-particle production cross sections have been calculated including higher-order QCD corrections. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with experimental data from the CERN S(p anti-p)S Collider and the Fermilab Tevatron.
[ { "created": "Wed, 25 Nov 1992 17:11:02 GMT", "version": "v1" }, { "created": "Thu, 26 Nov 1992 15:53:13 GMT", "version": "v2" }, { "created": "Sat, 28 Nov 1992 14:07:59 GMT", "version": "v3" } ]
2009-10-22
[ [ "Borzumati", "F. M.", "" ], [ "Kniehl", "B. A.", "" ], [ "Kramer", "G.", "" ] ]
Inclusive single-particle production cross sections have been calculated including higher-order QCD corrections. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with experimental data from the CERN S(p anti-p)S Collider and the Fermilab Tevatron.
hep-ph/9907415
null
Flavio Pereira and Erasmo Ferreira
Zeros, Dips and Signs in pp and p$\rm\bf\bar p$ Elastic Amplitudes
LaTex, 9 pages, 5 figures. Submitted to Phys. Rev. D
Phys.Rev. D61 (2000) 077507
10.1103/PhysRevD.61.077507
null
hep-ph
null
The dips observed in the differential cross sections of elastic pp and p$\bar{\rm p}$ scattering are studied in terms of the locations of the zeros of the real and imaginary parts of the amplitude and of the sign of real part at large $|t|$. It is confirmed that the differences in shapes of the dips in the pp and p$\bar{\rm p}$ systems are determined by a change of sign of the real tail, which seems to be determined by perturbative QCD contributions.
[ { "created": "Mon, 19 Jul 1999 18:10:45 GMT", "version": "v1" } ]
2009-10-31
[ [ "Pereira", "Flavio", "" ], [ "Ferreira", "Erasmo", "" ] ]
The dips observed in the differential cross sections of elastic pp and p$\bar{\rm p}$ scattering are studied in terms of the locations of the zeros of the real and imaginary parts of the amplitude and of the sign of real part at large $|t|$. It is confirmed that the differences in shapes of the dips in the pp and p$\bar{\rm p}$ systems are determined by a change of sign of the real tail, which seems to be determined by perturbative QCD contributions.
1502.01171
R.C. Verma Dr.
R.C. Verma, Norikazu Yamada and Kosuke Odagiri
The First Estimates of Kinematically Forbidden D Meson Decays
11 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weak hadronic decay D^+ -> K^0\bar a_1^+ is kinematically forbidden at the peak mass values of the particles involved. However, occurrence of this decay has been reported with branching fraction (9.1 \plusminus 1.8) \cross 10^{-3} in the analysis of D^+ -> K^\bar0 4 \pi decay data. This is due to smearing effects on this decay caused mainly by the large width of a_1-resonance, which extends the phase space and allows this decay. Using a factorization model to evaluate decay amplitudes for external and internal W-emission diagrams, and incorporating Breit-Wigner smearing using the total a_1 width of 400 MeV, we obtain the first estimate for branching fraction of this decay to be 3.3 \cross 10^{-3} and 7.0 \cross 10^{-3}, for |V_1^{Da1} (0)|=0.40 and 1.50 respectively corresponding to different theoretical models, where |V_1^{Da1} (q^2)| is the vector form factor appearing in the D -> a_1 s-wave transition. The estimates are of the desired order of magnitude. We also predict branching fractions of its counterpart decays D^0 -> K^-\bar a_1^+ and D^0 -> K^0\bar a_1^0.
[ { "created": "Wed, 4 Feb 2015 12:14:41 GMT", "version": "v1" } ]
2015-02-05
[ [ "Verma", "R. C.", "" ], [ "Yamada", "Norikazu", "" ], [ "Odagiri", "Kosuke", "" ] ]
The weak hadronic decay D^+ -> K^0\bar a_1^+ is kinematically forbidden at the peak mass values of the particles involved. However, occurrence of this decay has been reported with branching fraction (9.1 \plusminus 1.8) \cross 10^{-3} in the analysis of D^+ -> K^\bar0 4 \pi decay data. This is due to smearing effects on this decay caused mainly by the large width of a_1-resonance, which extends the phase space and allows this decay. Using a factorization model to evaluate decay amplitudes for external and internal W-emission diagrams, and incorporating Breit-Wigner smearing using the total a_1 width of 400 MeV, we obtain the first estimate for branching fraction of this decay to be 3.3 \cross 10^{-3} and 7.0 \cross 10^{-3}, for |V_1^{Da1} (0)|=0.40 and 1.50 respectively corresponding to different theoretical models, where |V_1^{Da1} (q^2)| is the vector form factor appearing in the D -> a_1 s-wave transition. The estimates are of the desired order of magnitude. We also predict branching fractions of its counterpart decays D^0 -> K^-\bar a_1^+ and D^0 -> K^0\bar a_1^0.
2209.10945
Olli Koskivaara
Kimmo Kainulainen, Olli Koskivaara and Sami Nurmi
Tachyonic production of dark relics: a non-perturbative quantum study
21 pages, 8 figures
null
10.1007/JHEP04(2023)043
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study production of dark relics during reheating after the end of inflation in a system consisting of a non-minimally coupled spectator scalar field and the inflaton. We derive a set of renormalized quantum transport equations for the one-point function and the two-point function of the spectator field and solve them numerically. We find that our system can embody both tachyonic and parametric instabilities. The former is an expected result due to the non-minimal coupling, but the latter displays new features driven by a novel interplay of the two-point function with the Ricci scalar. We find that when the parametric instability driven by the two-point function takes place, it dominates the total particle production. The quantitative results are also found to be highly sensitive to the model parameters.
[ { "created": "Thu, 22 Sep 2022 11:48:53 GMT", "version": "v1" } ]
2023-05-03
[ [ "Kainulainen", "Kimmo", "" ], [ "Koskivaara", "Olli", "" ], [ "Nurmi", "Sami", "" ] ]
We study production of dark relics during reheating after the end of inflation in a system consisting of a non-minimally coupled spectator scalar field and the inflaton. We derive a set of renormalized quantum transport equations for the one-point function and the two-point function of the spectator field and solve them numerically. We find that our system can embody both tachyonic and parametric instabilities. The former is an expected result due to the non-minimal coupling, but the latter displays new features driven by a novel interplay of the two-point function with the Ricci scalar. We find that when the parametric instability driven by the two-point function takes place, it dominates the total particle production. The quantitative results are also found to be highly sensitive to the model parameters.
2406.05920
Jonathan Rosner
Marek Karliner and Jonathan L. Rosner
Possible mixing of a diquark-antidiquark with a $p \bar p$ hadronic molecule
7 pages, one figure
null
null
EFI 24-4
hep-ph
http://creativecommons.org/licenses/by/4.0/
We discuss the possibility that the two nearby resonances observed by BESIII partially below the \,$p\bar p$\, threshold might be due to mixing between two metastable states with the same $J^{PC}=0^{-+}$ quantum numbers, but rather different internal structure. One is a $p \bar p$ hadronic molecule and the other a bound state of a light-quark diquark and an antidiquark, both with spin 1 and isospin 0, a composite color antitriplet and triplet, respectively. The doubling of resonances, one of which may be interpreted as a hadronic molecule, while the other arises from $q \bar q$ annihilation in a state with vacuum quantum numbers may be a more general feature than the specific case considered here.
[ { "created": "Sun, 9 Jun 2024 21:25:09 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2024 22:31:03 GMT", "version": "v2" }, { "created": "Tue, 13 Aug 2024 18:20:25 GMT", "version": "v3" } ]
2024-08-15
[ [ "Karliner", "Marek", "" ], [ "Rosner", "Jonathan L.", "" ] ]
We discuss the possibility that the two nearby resonances observed by BESIII partially below the \,$p\bar p$\, threshold might be due to mixing between two metastable states with the same $J^{PC}=0^{-+}$ quantum numbers, but rather different internal structure. One is a $p \bar p$ hadronic molecule and the other a bound state of a light-quark diquark and an antidiquark, both with spin 1 and isospin 0, a composite color antitriplet and triplet, respectively. The doubling of resonances, one of which may be interpreted as a hadronic molecule, while the other arises from $q \bar q$ annihilation in a state with vacuum quantum numbers may be a more general feature than the specific case considered here.
0704.2798
Lance Dixon
Zvi Bern, Lance J. Dixon, David A. Kosower
On-Shell Methods in Perturbative QCD
49 pages, 15 figures. v2: minor typos corrected
Annals Phys.322:1587-1634,2007
10.1016/j.aop.2007.04.014
UCLA/07/TEP/11, SLAC-PUB-12447, SPhT-T07/039
hep-ph
null
We review on-shell methods for computing multi-parton scattering amplitudes in perturbative QCD, utilizing their unitarity and factorization properties. We focus on aspects which are useful for the construction of one-loop amplitudes needed for phenomenological studies at the Large Hadron Collider.
[ { "created": "Fri, 20 Apr 2007 21:48:53 GMT", "version": "v1" }, { "created": "Wed, 30 May 2007 16:54:54 GMT", "version": "v2" } ]
2010-11-15
[ [ "Bern", "Zvi", "" ], [ "Dixon", "Lance J.", "" ], [ "Kosower", "David A.", "" ] ]
We review on-shell methods for computing multi-parton scattering amplitudes in perturbative QCD, utilizing their unitarity and factorization properties. We focus on aspects which are useful for the construction of one-loop amplitudes needed for phenomenological studies at the Large Hadron Collider.
hep-ph/9707224
Aude Gehrmann
A. Gehrmann-De Ridder and E.W.N. Glover (Durham)
A complete ${\cal O}(\alpha \alpha_s)$ calculation of the Photon + 1 Jet rate in $e^+e^-$ annihilation
59 pages, LaTeX, 8 Postscript figures included, a few typos corrected, one reference added, version to appear in Nucl.Phys.B
Nucl.Phys.B517:269-323,1998
10.1016/S0550-3213(97)00818-3
DTP/97/26
hep-ph
null
We present a complete calculation of the photon +~1 jet rate in $e^+e^-$ annihilation up to ${\cal O}(\alpha \alpha_{s})$. Although formally of next-to-leading order in perturbation theory, this calculation contains several ingredients appropriate to a next-to-next-to-leading order calculation of jet observables. In particular, we describe a generalization of the commonly used phase space slicing method to isolate the singularities present when more than one particle is unresolved. Within this approach, we analytically evaluate the singularities associated with the following double unresolved regions; triple collinear, soft/collinear and double single collinear configurations as well as those from the collinear limit of virtual graphs. By comparing the results of our calculation with the existing data on the photon +~1 jet rate from the ALEPH Collaboration at CERN, we make a next-to-leading order determination of the process-independent non-perturbative quark-to-photon fragmentation function $D_{q \to \gamma}(z,\mu_{F})$ at ${\cal O}(\alpha \alpha_{s})$. As a first application of this measurement allied with our improved perturbative calculation, we determine the dependence of the isolated photon +~1 jet cross section in a democratic clustering approach on the jet resolution parameter $\ycut$ at next-to-leading order. The next-to-leading order corrections to this observable are moderate but improve the agreement between theoretical prediction and experimental data.
[ { "created": "Wed, 2 Jul 1997 16:46:16 GMT", "version": "v1" }, { "created": "Tue, 24 Feb 1998 09:34:04 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ridder", "A. Gehrmann-De", "", "Durham" ], [ "Glover", "E. W. N.", "", "Durham" ] ]
We present a complete calculation of the photon +~1 jet rate in $e^+e^-$ annihilation up to ${\cal O}(\alpha \alpha_{s})$. Although formally of next-to-leading order in perturbation theory, this calculation contains several ingredients appropriate to a next-to-next-to-leading order calculation of jet observables. In particular, we describe a generalization of the commonly used phase space slicing method to isolate the singularities present when more than one particle is unresolved. Within this approach, we analytically evaluate the singularities associated with the following double unresolved regions; triple collinear, soft/collinear and double single collinear configurations as well as those from the collinear limit of virtual graphs. By comparing the results of our calculation with the existing data on the photon +~1 jet rate from the ALEPH Collaboration at CERN, we make a next-to-leading order determination of the process-independent non-perturbative quark-to-photon fragmentation function $D_{q \to \gamma}(z,\mu_{F})$ at ${\cal O}(\alpha \alpha_{s})$. As a first application of this measurement allied with our improved perturbative calculation, we determine the dependence of the isolated photon +~1 jet cross section in a democratic clustering approach on the jet resolution parameter $\ycut$ at next-to-leading order. The next-to-leading order corrections to this observable are moderate but improve the agreement between theoretical prediction and experimental data.
1604.03905
Daniel G. Figueroa
Daniel G. Figueroa, Christian T. Byrnes
The Standard Model Higgs as the origin of the hot Big Bang
6 pages, 2 figures, minor changes with new figures to match published version in PLB
null
10.1016/j.physletb.2017.01.059
CERN-TH-2016-088
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If the Standard Model (SM) Higgs is weakly coupled to the inflationary sector, the Higgs is expected to be universally in the form of a condensate towards the end of inflation. The Higgs decays rapidly after inflation - via non-perturbative effects - into an out-of-equilibrium distribution of SM species, which thermalize soon afterwards. If the post-inflationary equation of state of the universe is stiff, $w \simeq +1$, the SM species eventually dominate the total energy budget. This provides a natural origin for the relativistic thermal plasma of SM species, required for the onset of the `hot Big Bang' era. The viability of this scenario requires the inflationary Hubble scale $H_*$ to be lower than the instability scale for Higgs vacuum decay, the Higgs not to generate too large curvature perturbations at cosmological scales, and the SM dominance to occur before Big Bang Nucleosynthesis. We show that successful reheating into the SM can only be obtained in the presence of a non-minimal coupling to gravity $\xi \gtrsim 1$, with a reheating temperature of $T_{\rm RH} \gtrsim \mathcal{O}(10^{10})\xi^{3/2}(H_*/10^{14}{\rm GeV})^2~{\rm GeV}$.
[ { "created": "Wed, 13 Apr 2016 18:32:10 GMT", "version": "v1" }, { "created": "Thu, 29 Jun 2017 16:46:01 GMT", "version": "v2" } ]
2017-06-30
[ [ "Figueroa", "Daniel G.", "" ], [ "Byrnes", "Christian T.", "" ] ]
If the Standard Model (SM) Higgs is weakly coupled to the inflationary sector, the Higgs is expected to be universally in the form of a condensate towards the end of inflation. The Higgs decays rapidly after inflation - via non-perturbative effects - into an out-of-equilibrium distribution of SM species, which thermalize soon afterwards. If the post-inflationary equation of state of the universe is stiff, $w \simeq +1$, the SM species eventually dominate the total energy budget. This provides a natural origin for the relativistic thermal plasma of SM species, required for the onset of the `hot Big Bang' era. The viability of this scenario requires the inflationary Hubble scale $H_*$ to be lower than the instability scale for Higgs vacuum decay, the Higgs not to generate too large curvature perturbations at cosmological scales, and the SM dominance to occur before Big Bang Nucleosynthesis. We show that successful reheating into the SM can only be obtained in the presence of a non-minimal coupling to gravity $\xi \gtrsim 1$, with a reheating temperature of $T_{\rm RH} \gtrsim \mathcal{O}(10^{10})\xi^{3/2}(H_*/10^{14}{\rm GeV})^2~{\rm GeV}$.
hep-ph/0301121
Andrea Brignole
A. Brignole, J.A. Casas, J.R. Espinosa, I. Navarro
Low-scale supersymmetry breaking: effective description, electroweak breaking and phenomenology
LaTeX, 47 pages, 5 figures; typos corrected, to appear in Nucl. Phys. B
Nucl.Phys. B666 (2003) 105-143
10.1016/S0550-3213(03)00539-X
DFPD-02/TH/34
hep-ph hep-th
null
We consider supersymmetric scenarios in which the scale of SUSY breaking is low, sqrt{F}=O(TeV). Instead of studying specific models of this type, e.g. those with extra dimensions and low fundamental scale, we follow a model-independent approach based on a general effective Lagrangian, in which the MSSM supermultiplets are effectively coupled to a singlet associated to SUSY breaking. Our goal is to analyse the interplay bewteen SUSY breaking and electroweak breaking, generalizing earlier results. The conventional MSSM picture can be substantially modified, mainly because the Higgs potential contains additional effective quartic terms and resembles that of two-Higgs-doublet models, with an additional singlet. Novel opportunities to achieve electroweak breaking arise, and the electroweak scale may be obtained in a less fine-tuned way. Also the Higgs spectrum can be strikingly changed, and the lightest state can be much heavier than in usual supersymmetric scenarios. Other effects appear in the chargino and neutralino sectors, which contain the goldstino. Finally, we discuss the role of electroweak breaking in processes in which two goldstinos could be emitted, such as fermion-antifermion annihilation and the invisible decay of a Z boson or of neutral Higgs bosons.
[ { "created": "Thu, 16 Jan 2003 19:19:19 GMT", "version": "v1" }, { "created": "Tue, 15 Jul 2003 14:42:12 GMT", "version": "v2" } ]
2010-04-05
[ [ "Brignole", "A.", "" ], [ "Casas", "J. A.", "" ], [ "Espinosa", "J. R.", "" ], [ "Navarro", "I.", "" ] ]
We consider supersymmetric scenarios in which the scale of SUSY breaking is low, sqrt{F}=O(TeV). Instead of studying specific models of this type, e.g. those with extra dimensions and low fundamental scale, we follow a model-independent approach based on a general effective Lagrangian, in which the MSSM supermultiplets are effectively coupled to a singlet associated to SUSY breaking. Our goal is to analyse the interplay bewteen SUSY breaking and electroweak breaking, generalizing earlier results. The conventional MSSM picture can be substantially modified, mainly because the Higgs potential contains additional effective quartic terms and resembles that of two-Higgs-doublet models, with an additional singlet. Novel opportunities to achieve electroweak breaking arise, and the electroweak scale may be obtained in a less fine-tuned way. Also the Higgs spectrum can be strikingly changed, and the lightest state can be much heavier than in usual supersymmetric scenarios. Other effects appear in the chargino and neutralino sectors, which contain the goldstino. Finally, we discuss the role of electroweak breaking in processes in which two goldstinos could be emitted, such as fermion-antifermion annihilation and the invisible decay of a Z boson or of neutral Higgs bosons.
hep-ph/0211132
Bennie F. L. Ward
B.F.L. Ward (1), S. Jadach (2) and Z. Was (2) ((1) Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, USA, (2) Henryk Niewodniczanski Institute of Nuclear Physics, Cracow, Poland)
Precision calculation for e+ e- -> 2f: the KK MC project
5 pages, 4 figures, 2 diagrams - presented by BFLW at RADCOR02
Nucl.Phys.Proc.Suppl. 116 (2003) 73-77
10.1016/S0920-5632(03)80147-0
UTHEP-02-0901
hep-ph
null
We present the current status of the coherent exclusive (CEEX) realization of the YFS theory for the processes in e+ e- -> 2f via the KK MC. We give a brief summary of the CEEX theory in comparison to the older (EEX) exclusive exponentiation theory and illustrate recent theoretical results relevant to the LEP2 and LC physics programs.
[ { "created": "Sat, 9 Nov 2002 15:31:22 GMT", "version": "v1" } ]
2009-11-07
[ [ "Ward", "B. F. L.", "" ], [ "Jadach", "S.", "" ], [ "Was", "Z.", "" ] ]
We present the current status of the coherent exclusive (CEEX) realization of the YFS theory for the processes in e+ e- -> 2f via the KK MC. We give a brief summary of the CEEX theory in comparison to the older (EEX) exclusive exponentiation theory and illustrate recent theoretical results relevant to the LEP2 and LC physics programs.
1903.08296
Lucas Johns
Lucas Johns and George M. Fuller
Self-interacting sterile neutrino dark matter: the heavy-mediator case
10 pages, 6 figures
Phys. Rev. D 100, 023533 (2019)
10.1103/PhysRevD.100.023533
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For active-sterile mixing to be responsible for the full relic abundance of dark matter additional new physics is needed beyond the keV-scale sterile neutrino itself. The extra ingredient we consider here is the presence of self-interactions among the sterile neutrinos. We examine whether active-to-sterile conversion is amplified enough in this scenario that the observed abundance of dark matter can be obtained with a subconstraint mixing angle. This turns out never to be the case in the region we explore: either self-interactions have too small an impact and cannot escape bounds on the mass and mixing angle, or they have too great an impact and cause dark matter to be overproduced. The sharp transition from marginal to excessive effectiveness occurs because a resonance criterion is met in the effective in-medium mixing angle. Once the system goes resonant the game is as good as over, as nonlinearity in the Boltzmann equation leads to runaway production of sterile neutrinos, beginning at a plasma temperature of a few hundred MeV and typically ending at a few tens of MeV. The scenario is therefore ruled out largely by its own dynamics. In this study we focus exclusively on mediators heavier than $\sim 1$ GeV; future work will extend the analysis to lighter mediators, allowing for contact to be made with the kinds of scenarios motivated by issues of small-scale structure.
[ { "created": "Wed, 20 Mar 2019 00:19:46 GMT", "version": "v1" }, { "created": "Sat, 3 Aug 2019 23:05:33 GMT", "version": "v2" } ]
2019-08-06
[ [ "Johns", "Lucas", "" ], [ "Fuller", "George M.", "" ] ]
For active-sterile mixing to be responsible for the full relic abundance of dark matter additional new physics is needed beyond the keV-scale sterile neutrino itself. The extra ingredient we consider here is the presence of self-interactions among the sterile neutrinos. We examine whether active-to-sterile conversion is amplified enough in this scenario that the observed abundance of dark matter can be obtained with a subconstraint mixing angle. This turns out never to be the case in the region we explore: either self-interactions have too small an impact and cannot escape bounds on the mass and mixing angle, or they have too great an impact and cause dark matter to be overproduced. The sharp transition from marginal to excessive effectiveness occurs because a resonance criterion is met in the effective in-medium mixing angle. Once the system goes resonant the game is as good as over, as nonlinearity in the Boltzmann equation leads to runaway production of sterile neutrinos, beginning at a plasma temperature of a few hundred MeV and typically ending at a few tens of MeV. The scenario is therefore ruled out largely by its own dynamics. In this study we focus exclusively on mediators heavier than $\sim 1$ GeV; future work will extend the analysis to lighter mediators, allowing for contact to be made with the kinds of scenarios motivated by issues of small-scale structure.
2209.02619
Wojciech Broniowski
Vanamali Shastry, Wojciech Broniowski, Enrique Ruiz Arriola
Generalized quasi, Ioffe-time, and pseudo quark distributions of the pion in the Nambu--Jona-Lasinio model
extended discussion and a reference added, 23 pages, 12 figures
null
10.1103/PhysRevD.106.114035
null
hep-ph hep-lat
http://creativecommons.org/licenses/by/4.0/
We analyze the generalized quasi, Ioffe-time, and pseudo distributions of the valence quarks in the pion at the quark model scale. We use the framework of the Nambu-Jona-Lasinio model and investigate the basic question of how fast the pion has to move to effectively reach the infinite momentum limit, where the approach can provide the information on the generalized parton distribution functions. We consider both the vector distributions and the transversity distributions, related to the spin densities. With the developed analytic expressions, we conclude that to effectively approach the infinite momentum limit, one roughly needs the pion momenta of the order of $\sim 3$GeV. We also explore polynomiality of the quasi distributions and study the generalized quasi form factors. The issue of separability of the transverse and longitudinal dynamics in the model is studied with the help of the generalized Ioffe-time distributions, with the conclusion that the breaking is not substantial, unless the momentum transfer $t$ is large. We also provide an estimate of the range of the Ioffe-time values needed to obtain the generalized parton distributions with a reasonable accuracy. Our model results, which are analytic or semi-analytic, provide a valuable insight into the theoretical formalism and illustrate the intricate features of the investigated distributions.
[ { "created": "Tue, 6 Sep 2022 16:18:30 GMT", "version": "v1" }, { "created": "Tue, 22 Nov 2022 20:17:08 GMT", "version": "v2" } ]
2023-01-11
[ [ "Shastry", "Vanamali", "" ], [ "Broniowski", "Wojciech", "" ], [ "Arriola", "Enrique Ruiz", "" ] ]
We analyze the generalized quasi, Ioffe-time, and pseudo distributions of the valence quarks in the pion at the quark model scale. We use the framework of the Nambu-Jona-Lasinio model and investigate the basic question of how fast the pion has to move to effectively reach the infinite momentum limit, where the approach can provide the information on the generalized parton distribution functions. We consider both the vector distributions and the transversity distributions, related to the spin densities. With the developed analytic expressions, we conclude that to effectively approach the infinite momentum limit, one roughly needs the pion momenta of the order of $\sim 3$GeV. We also explore polynomiality of the quasi distributions and study the generalized quasi form factors. The issue of separability of the transverse and longitudinal dynamics in the model is studied with the help of the generalized Ioffe-time distributions, with the conclusion that the breaking is not substantial, unless the momentum transfer $t$ is large. We also provide an estimate of the range of the Ioffe-time values needed to obtain the generalized parton distributions with a reasonable accuracy. Our model results, which are analytic or semi-analytic, provide a valuable insight into the theoretical formalism and illustrate the intricate features of the investigated distributions.
2107.14300
Pierre Sikivie
Pierre Sikivie
Clean energy from dark matter?
5 pages, no figures
null
null
null
hep-ph astro-ph.GA physics.app-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A contribution to Frank Wilczek's 70th birthday's festschrift, this brief note considers how much power can be extracted from dark matter.
[ { "created": "Thu, 29 Jul 2021 19:56:57 GMT", "version": "v1" } ]
2021-08-02
[ [ "Sikivie", "Pierre", "" ] ]
A contribution to Frank Wilczek's 70th birthday's festschrift, this brief note considers how much power can be extracted from dark matter.
1808.04774
Bhavesh Chauhan
Bhavesh Chauhan, Subhendra Mohanty
Signature of light sterile neutrinos at IceCube
version to appear in Phys. Rev. D
Phys. Rev. D 98, 083021 (2018)
10.1103/PhysRevD.98.083021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The MiniBooNe collaboration has recently reported evidence for a light sterile neutrino with large mixing angles thus corroborating the measurement by LSND twenty years ago. Such a state would be directly in conflict with Planck measurement of BBN $N_{eff}$ unless there is self-interaction in the sterile sector. Our objective is to investigate if such interactions could result in resonant absorption in the cosmogenic neutrino spectrum and its consequences for the IceCube experiment. We show that it is possible to give independent bounds on sterile neutrino parameter space from IceCube observations with the dips in the spectrum corresponding to the neutrino masses.
[ { "created": "Tue, 14 Aug 2018 16:12:16 GMT", "version": "v1" }, { "created": "Sun, 21 Oct 2018 15:48:16 GMT", "version": "v2" } ]
2018-10-31
[ [ "Chauhan", "Bhavesh", "" ], [ "Mohanty", "Subhendra", "" ] ]
The MiniBooNe collaboration has recently reported evidence for a light sterile neutrino with large mixing angles thus corroborating the measurement by LSND twenty years ago. Such a state would be directly in conflict with Planck measurement of BBN $N_{eff}$ unless there is self-interaction in the sterile sector. Our objective is to investigate if such interactions could result in resonant absorption in the cosmogenic neutrino spectrum and its consequences for the IceCube experiment. We show that it is possible to give independent bounds on sterile neutrino parameter space from IceCube observations with the dips in the spectrum corresponding to the neutrino masses.
hep-ph/9607227
Uma Mahanta
Uma Mahanta
Implications of m_t and R_b on zt\bar{t} couplings in standard ETC models
Revised version submitted with recent LEP data on R_b
Phys.Lett. B392 (1997) 145-149
10.1016/S0370-2693(96)01535-3
MRI-PHY-96-21
hep-ph
null
In standard ETC models the sideways and diagonal ETC interactions contribute to $\delta R_b$ with opposite signs. The aim of this article is to study the implications of the CDF value for m_t and the LEP value for R_b on $zt\bar{t}$ couplings where the LH sideways and diagonal ETC effects interfere constructively. We find that for m_t=175 Gev, $\delta R_b =.0022$ and m^2_s=m^2_d, F^t_v and F^t_a are modified by 19% and 7% respectively from their SM values. The constrains implied by these deviations on diagonal ETC scenarios and the feasibility of probing them at NLC through polarization and angular distribution studies in $e^+e^- \to t\bar{t}$ are also considered.
[ { "created": "Wed, 3 Jul 1996 10:16:36 GMT", "version": "v1" }, { "created": "Tue, 5 Nov 1996 21:43:20 GMT", "version": "v2" } ]
2016-09-06
[ [ "Mahanta", "Uma", "" ] ]
In standard ETC models the sideways and diagonal ETC interactions contribute to $\delta R_b$ with opposite signs. The aim of this article is to study the implications of the CDF value for m_t and the LEP value for R_b on $zt\bar{t}$ couplings where the LH sideways and diagonal ETC effects interfere constructively. We find that for m_t=175 Gev, $\delta R_b =.0022$ and m^2_s=m^2_d, F^t_v and F^t_a are modified by 19% and 7% respectively from their SM values. The constrains implied by these deviations on diagonal ETC scenarios and the feasibility of probing them at NLC through polarization and angular distribution studies in $e^+e^- \to t\bar{t}$ are also considered.
hep-ph/9404215
null
Hans-Thomas Elze
Quantum Decoherence, Entropy and Thermalization in Strong Interactions at High Energy
45 pages, 2 figures
Nucl.Phys.B436:213-264,1995
10.1016/0550-3213(94)00523-H
null
hep-ph
null
Entropy is generated in high-multiplying events by a dynamical separation of strongly interacting systems into partons and unobservable environment modes (almost constant field configurations) due to confinement.
[ { "created": "Tue, 5 Apr 1994 12:50:36 GMT", "version": "v1" } ]
2011-08-04
[ [ "Elze", "Hans-Thomas", "" ] ]
Entropy is generated in high-multiplying events by a dynamical separation of strongly interacting systems into partons and unobservable environment modes (almost constant field configurations) due to confinement.
1606.01298
Li Cheng
Li Cheng and German Valencia
Two Higgs doublet models augmented by a scalar color octet
23 pages, 10 figures; Matched the publication version
null
10.1007/JHEP09(2016)079
CoEPP-MN-16-15
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHC is now studying in detail the couplings of the Higgs boson in order to determine if there is new physics. Many recent studies have examined the available fits to Higgs couplings from the perspective of constraining two Higgs doublet models (2HDM). In this paper we extend those studies to include constraints on the one loop couplings of the Higgs to gluons and photons. These couplings are particularly sensitive to the existence of new colored particles that are hard to detect otherwise and we use them to constrain a 2HDM augmented with a color-octet scalar, a possibility motivated by minimal flavor violation. We first study theoretical constraints on this model and then compare them with LHC measurements.
[ { "created": "Fri, 3 Jun 2016 22:48:26 GMT", "version": "v1" }, { "created": "Tue, 14 Jun 2016 18:30:02 GMT", "version": "v2" }, { "created": "Tue, 13 Sep 2016 21:37:58 GMT", "version": "v3" } ]
2016-10-12
[ [ "Cheng", "Li", "" ], [ "Valencia", "German", "" ] ]
The LHC is now studying in detail the couplings of the Higgs boson in order to determine if there is new physics. Many recent studies have examined the available fits to Higgs couplings from the perspective of constraining two Higgs doublet models (2HDM). In this paper we extend those studies to include constraints on the one loop couplings of the Higgs to gluons and photons. These couplings are particularly sensitive to the existence of new colored particles that are hard to detect otherwise and we use them to constrain a 2HDM augmented with a color-octet scalar, a possibility motivated by minimal flavor violation. We first study theoretical constraints on this model and then compare them with LHC measurements.
hep-ph/9307201
null
Howard E. Haber and Ralf Hempfling
The Renormalization-Group Improved Higgs Sector of the Minimal Supersymmetric Model
51 pages, SCIPP-91/33 (July, 1992; revised June, 1993), PHYZZX macropackage
Phys.Rev. D48 (1993) 4280-4309
10.1103/PhysRevD.48.4280
null
hep-ph
null
In the minimal supersymmetric model (MSSM) all Higgs self-coupling parameters are related to gauge couplings at tree-level. Leading-logarithmic radiative corrections to these quantities can be summed using renormalization group techniques. By this procedure we obtain complete leading-log radiative corrections to the Higgs masses, the CP-even Higgs mixing angle, and trilinear Higgs couplings. Additional corrections due to squark mixing can be explicitly incorporated into this formalism. These results incorporate nearly all potentially large corrections. Mass shifts to the neutral CP-even Higgs bosons grow with the fourth power of the top-quark mass and can be significant. The phenomenological consequences of these results are examined.
[ { "created": "Thu, 1 Jul 1993 08:44:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Haber", "Howard E.", "" ], [ "Hempfling", "Ralf", "" ] ]
In the minimal supersymmetric model (MSSM) all Higgs self-coupling parameters are related to gauge couplings at tree-level. Leading-logarithmic radiative corrections to these quantities can be summed using renormalization group techniques. By this procedure we obtain complete leading-log radiative corrections to the Higgs masses, the CP-even Higgs mixing angle, and trilinear Higgs couplings. Additional corrections due to squark mixing can be explicitly incorporated into this formalism. These results incorporate nearly all potentially large corrections. Mass shifts to the neutral CP-even Higgs bosons grow with the fourth power of the top-quark mass and can be significant. The phenomenological consequences of these results are examined.
0711.1708
Jihn E. Kim
Jihn E. Kim
Axion as a CDM component
9 pages with 11 figures. Based on talks at Lepton-Photon 2007 and APPC10
null
null
SNUTP 07-11
hep-ph astro-ph hep-th
null
I discuss the essential features of the QCD axion: the strong CP solution and hence its theoretical necessity. I also review the effects of the QCD axion on astrophysics and cosmology, in particular with emphasis on its role in the dark matter component together with its supersymmetric partner axino. It is pointed out that string theory may or may not give a detectable QCD axion.
[ { "created": "Mon, 12 Nov 2007 04:45:32 GMT", "version": "v1" }, { "created": "Tue, 20 Nov 2007 05:02:43 GMT", "version": "v2" } ]
2007-11-20
[ [ "Kim", "Jihn E.", "" ] ]
I discuss the essential features of the QCD axion: the strong CP solution and hence its theoretical necessity. I also review the effects of the QCD axion on astrophysics and cosmology, in particular with emphasis on its role in the dark matter component together with its supersymmetric partner axino. It is pointed out that string theory may or may not give a detectable QCD axion.
2105.03272
Yasaman Farzan
Yasaman Farzan
On the Tau flavor of the cosmic neutrino flux
18 pages, 3 figures; v2: matching JHEP version; comment on intrinsic c quark added
JHEP 07 (2021) 174
10.1007/JHEP07(2021)174
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Observation of high energy cosmic neutrinos by ICECUBE has ushered in a new era in exploring both cosmos and new physics beyond the Standard Model (SM). In the standard picture, although mostly $\nu_\mu$ and $\nu_e$ are produced in the source, oscillation will produce $\nu_\tau$ {\it en route}. Certain beyond SM scenarios, like interaction with ultralight DM can alter this picture. Thus, the flavor composition of the cosmic neutrino flux can open up the possibility of exploring certain beyond the SM scenarios that are inaccessible otherwise. We show that the $\tau$ flavor holds a special place among the neutrino flavors in elucidating new physics. Interpreting the two anomalous events observed by ANITA as $\nu_\tau$ events makes the tau flavor even more intriguing. We study how the detection of the two tau events by ICECUBE constrains the interaction of the neutrinos with ultralight dark matter and discuss the implications of this interaction for even higher energy cosmic neutrinos detectable by future radio telescopes such as ARA, ARIANNA and GRAND. We also revisit the $3+1$ neutrino scheme as a solution to the two anomalous ANITA events and clarify a misconception that exists in the literature about the evolution of high energy neutrinos in matter within the $3+1$ scheme with a possibility of scattering off nuclei. We show that the existing bounds on the flux of $\nu_\tau$ with energy of EeV rules out this solution for the ANITA events. We show that the $3+1$ solution can be saved from both this bound and from the bound on the extra relativistic degrees of freedom in the early universe by turning on the interaction of neutrinos with ultralight dark matter.
[ { "created": "Fri, 7 May 2021 13:53:15 GMT", "version": "v1" }, { "created": "Wed, 18 Aug 2021 18:09:44 GMT", "version": "v2" } ]
2021-08-20
[ [ "Farzan", "Yasaman", "" ] ]
Observation of high energy cosmic neutrinos by ICECUBE has ushered in a new era in exploring both cosmos and new physics beyond the Standard Model (SM). In the standard picture, although mostly $\nu_\mu$ and $\nu_e$ are produced in the source, oscillation will produce $\nu_\tau$ {\it en route}. Certain beyond SM scenarios, like interaction with ultralight DM can alter this picture. Thus, the flavor composition of the cosmic neutrino flux can open up the possibility of exploring certain beyond the SM scenarios that are inaccessible otherwise. We show that the $\tau$ flavor holds a special place among the neutrino flavors in elucidating new physics. Interpreting the two anomalous events observed by ANITA as $\nu_\tau$ events makes the tau flavor even more intriguing. We study how the detection of the two tau events by ICECUBE constrains the interaction of the neutrinos with ultralight dark matter and discuss the implications of this interaction for even higher energy cosmic neutrinos detectable by future radio telescopes such as ARA, ARIANNA and GRAND. We also revisit the $3+1$ neutrino scheme as a solution to the two anomalous ANITA events and clarify a misconception that exists in the literature about the evolution of high energy neutrinos in matter within the $3+1$ scheme with a possibility of scattering off nuclei. We show that the existing bounds on the flux of $\nu_\tau$ with energy of EeV rules out this solution for the ANITA events. We show that the $3+1$ solution can be saved from both this bound and from the bound on the extra relativistic degrees of freedom in the early universe by turning on the interaction of neutrinos with ultralight dark matter.
hep-ph/0505259
Sergey Ostapchenko
S. Ostapchenko
Non-linear screening effects in high energy hadronic interactions
New version; calculation of single diffraction cross section included
Phys.Rev.D74:014026,2006
10.1103/PhysRevD.74.014026
null
hep-ph
null
Non-linear effects in hadronic interactions are treated by means of enhanced pomeron diagrams, assuming that pomeron-pomeron coupling is dominated by soft partonic processes. It is shown that the approach allows to resolve a seeming contradiction between realistic parton momentum distributions, measured in deep inelastic scattering experiments, and the energy behavior of total proton-proton cross section. Also a general consistency with both ``soft'' and ``hard'' diffraction data is demonstrated. An important feature of the proposed scheme is that the contribution of semi-hard processes to the interaction eikonal contains a significant non-factorizable part. On the other hand, the approach preserves the QCD factorization picture for inclusive high p_t jet production.
[ { "created": "Mon, 30 May 2005 16:41:27 GMT", "version": "v1" }, { "created": "Mon, 27 Mar 2006 12:03:01 GMT", "version": "v2" }, { "created": "Thu, 22 Jun 2006 18:47:56 GMT", "version": "v3" } ]
2011-07-19
[ [ "Ostapchenko", "S.", "" ] ]
Non-linear effects in hadronic interactions are treated by means of enhanced pomeron diagrams, assuming that pomeron-pomeron coupling is dominated by soft partonic processes. It is shown that the approach allows to resolve a seeming contradiction between realistic parton momentum distributions, measured in deep inelastic scattering experiments, and the energy behavior of total proton-proton cross section. Also a general consistency with both ``soft'' and ``hard'' diffraction data is demonstrated. An important feature of the proposed scheme is that the contribution of semi-hard processes to the interaction eikonal contains a significant non-factorizable part. On the other hand, the approach preserves the QCD factorization picture for inclusive high p_t jet production.
hep-ph/0602021
Juan Jose Sanz-Cillero
J. J. Sanz-Cillero
V+A and V-A Correlators at Large NC: From OPE to Resonance Theory
6 pages, 2 figures, proceedings of the talk given at HSQCD 2005, St. Petersburg, Russia, September 20-24 2005
null
null
null
hep-ph
null
The spin-1 correlators are analysed in this talk through a large NC resonance theory. The matching to perturbative QCD and the first terms in the OPE constrains the hadronic parameters. A further sum-rule analysis shows the wider range of validity of the resonance description, which can help to discern the proper structure of the QCD mass spectrum.
[ { "created": "Thu, 2 Feb 2006 11:30:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sanz-Cillero", "J. J.", "" ] ]
The spin-1 correlators are analysed in this talk through a large NC resonance theory. The matching to perturbative QCD and the first terms in the OPE constrains the hadronic parameters. A further sum-rule analysis shows the wider range of validity of the resonance description, which can help to discern the proper structure of the QCD mass spectrum.
1705.01063
Benjamin Fuks
Jack Y. Araz, Mariana Frank, Benjamin Fuks
Differentiating $U(1)^\prime$ supersymmetric models with right sneutrino and neutralino dark matter
21 pages, 11 figures, version accepted by PRD
Phys. Rev. D 96, 015017 (2017)
10.1103/PhysRevD.96.015017
CUMQ/HEP 194
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a detailed analysis of dark matter signals of supersymmetric models containing an extra $U(1)^\prime$ gauge group. We investigate scenarios in which either the right sneutrino or the lightest neutralino are phenomenologically acceptable dark matter candidates and we explore the parameter spaces of different supersymmetric realisations featuring an extra $U(1)^\prime$. We impose consistency with low energy observables, with known mass limits for the superpartners and $Z^\prime$ bosons, as well as with Higgs boson signal strengths, and we moreover verify that predictions for the anomalous magnetic moment of the muon agree with the experimental value and require that the dark matter candidate satisfies the observed relic density and direct and indirect dark matter detection constraints. For the case where the sneutrino is the dark matter candidate, we find distinguishing characteristics among different $U(1)^\prime$ mixing angles. If the neutralino is the lightest supersymmetric particle, its mass is heavier than that of the light sneutrino in scenarios where the latter is a dark matter candidate, the parameter space is less restricted and differentiation between models is more difficult. We finally comment on the possible collider tests of these models.
[ { "created": "Tue, 2 May 2017 16:43:58 GMT", "version": "v1" }, { "created": "Tue, 18 Jul 2017 15:43:38 GMT", "version": "v2" } ]
2017-07-26
[ [ "Araz", "Jack Y.", "" ], [ "Frank", "Mariana", "" ], [ "Fuks", "Benjamin", "" ] ]
We perform a detailed analysis of dark matter signals of supersymmetric models containing an extra $U(1)^\prime$ gauge group. We investigate scenarios in which either the right sneutrino or the lightest neutralino are phenomenologically acceptable dark matter candidates and we explore the parameter spaces of different supersymmetric realisations featuring an extra $U(1)^\prime$. We impose consistency with low energy observables, with known mass limits for the superpartners and $Z^\prime$ bosons, as well as with Higgs boson signal strengths, and we moreover verify that predictions for the anomalous magnetic moment of the muon agree with the experimental value and require that the dark matter candidate satisfies the observed relic density and direct and indirect dark matter detection constraints. For the case where the sneutrino is the dark matter candidate, we find distinguishing characteristics among different $U(1)^\prime$ mixing angles. If the neutralino is the lightest supersymmetric particle, its mass is heavier than that of the light sneutrino in scenarios where the latter is a dark matter candidate, the parameter space is less restricted and differentiation between models is more difficult. We finally comment on the possible collider tests of these models.
hep-ph/9511325
null
Wei Lu, Xue Qian Li and Haiming Hu
Spin-dependent structure functions $\hat g_1$ and $\hat g_2$ for inclusive spin-half baryon production in electron-positron annihilation
RevTex, four Ps figures, to appear in Phys. Rev. D
Phys.Rev. D53 (1996) 131-137
10.1103/PhysRevD.53.131
null
hep-ph
null
Two spin-dependent structure functions $\hat g_1$ and $\hat g_2$ for the inclusive spin-half baryon production in electron-positron annihilation are studied in the context of QCD factorization as well as in the naive quark parton model. As a result, it is found that the sum of $\hat g_1$ and $\hat g_2$ is related to $\hat h_1$ and $\hat g_T$, two quark fragmentation functions defined by Jaffe and Ji. In connection with the measurement of quark fragmentation functions, the possible phenomenological consequences are discussed.
[ { "created": "Thu, 16 Nov 1995 00:24:53 GMT", "version": "v1" }, { "created": "Fri, 17 Nov 1995 13:06:48 GMT", "version": "v2" } ]
2009-10-28
[ [ "Lu", "Wei", "" ], [ "Li", "Xue Qian", "" ], [ "Hu", "Haiming", "" ] ]
Two spin-dependent structure functions $\hat g_1$ and $\hat g_2$ for the inclusive spin-half baryon production in electron-positron annihilation are studied in the context of QCD factorization as well as in the naive quark parton model. As a result, it is found that the sum of $\hat g_1$ and $\hat g_2$ is related to $\hat h_1$ and $\hat g_T$, two quark fragmentation functions defined by Jaffe and Ji. In connection with the measurement of quark fragmentation functions, the possible phenomenological consequences are discussed.
1810.09101
Ning Yu
Ning Yu and Xiaofeng Luo
Particle decay from statistical thermal model in high energy nucleus-nucleus collision
15 pages, 9 figures
Eur. Phys. J. A (2019) 55:26
10.1140/epja/i2019-12691-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In high energy nucleus-nucleus collisions, it is difficult to measure the contributions of resonance strong decay and weak decay to the final measured hadrons as well as the corresponding effects on some physical observables. To provide a reference from statistical thermal model, we performed a systematic analysis for the energy dependence of particle yield and yield ratios in Au + Au collisions. We found that the primary fraction of final hadrons decreases with increasing collision energy and somehow saturates around $\sqrt{s_\textrm{NN}}$ = 10 GeV, indicating a limiting temperature in hadronic interactions. The fraction of strong or weak decay for final hadrons show a different energy dependence behavior comparing to the primarily produced hadrons. These energy dependences of various particle yield and yield ratios from strong or weak decay can provide us with baselines for many hadronic observables in high energy nucleus-nucleus collisions.
[ { "created": "Mon, 22 Oct 2018 06:22:45 GMT", "version": "v1" }, { "created": "Wed, 28 Nov 2018 07:59:07 GMT", "version": "v2" }, { "created": "Thu, 21 Feb 2019 12:52:41 GMT", "version": "v3" } ]
2019-02-22
[ [ "Yu", "Ning", "" ], [ "Luo", "Xiaofeng", "" ] ]
In high energy nucleus-nucleus collisions, it is difficult to measure the contributions of resonance strong decay and weak decay to the final measured hadrons as well as the corresponding effects on some physical observables. To provide a reference from statistical thermal model, we performed a systematic analysis for the energy dependence of particle yield and yield ratios in Au + Au collisions. We found that the primary fraction of final hadrons decreases with increasing collision energy and somehow saturates around $\sqrt{s_\textrm{NN}}$ = 10 GeV, indicating a limiting temperature in hadronic interactions. The fraction of strong or weak decay for final hadrons show a different energy dependence behavior comparing to the primarily produced hadrons. These energy dependences of various particle yield and yield ratios from strong or weak decay can provide us with baselines for many hadronic observables in high energy nucleus-nucleus collisions.
1806.02177
Pok Man Lo
C\'esar Fern\'andez-Ram\'irez, Pok Man Lo, Peter Petreczky
Thermodynamics of strange baryon system from coupled-channel analysis and missing states
10 pages, 7 figures; version appear in PRC with typos. in Fig.4 corrected
Phys. Rev. C 98, 044910 (2018)
10.1103/PhysRevC.98.044910
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the thermodynamics of the strange baryon system using an S-matrix formulation of statistical mechanics. For this purpose, we employ an existing coupled-channel study involving $\bar{K} N$, $\pi \Lambda$, and $\pi \Sigma$ interactions in the $S=-1$ sector. A novel method is proposed to extract an effective phase shift due to the interaction, which can subsequently be used to compute various thermal observables via a relativistic virial expansion. As an application of the calculation scheme, we compute the correlation of the net baryon number with strangeness ($\chi_{BS}$) for an interacting hadron gas. We show that the S-matrix approach, which entails a consistent treatment of resonances and naturally incorporates the additional hyperon states which are not listed by the Particle Data Group, leads to an improved description of the lattice data over the Hadron Resonance Gas model.
[ { "created": "Wed, 6 Jun 2018 13:37:38 GMT", "version": "v1" }, { "created": "Fri, 14 Dec 2018 07:07:46 GMT", "version": "v2" } ]
2018-12-17
[ [ "Fernández-Ramírez", "César", "" ], [ "Lo", "Pok Man", "" ], [ "Petreczky", "Peter", "" ] ]
We study the thermodynamics of the strange baryon system using an S-matrix formulation of statistical mechanics. For this purpose, we employ an existing coupled-channel study involving $\bar{K} N$, $\pi \Lambda$, and $\pi \Sigma$ interactions in the $S=-1$ sector. A novel method is proposed to extract an effective phase shift due to the interaction, which can subsequently be used to compute various thermal observables via a relativistic virial expansion. As an application of the calculation scheme, we compute the correlation of the net baryon number with strangeness ($\chi_{BS}$) for an interacting hadron gas. We show that the S-matrix approach, which entails a consistent treatment of resonances and naturally incorporates the additional hyperon states which are not listed by the Particle Data Group, leads to an improved description of the lattice data over the Hadron Resonance Gas model.
2204.02649
Hua-Xing Chen
Hua-Xing Chen, Wei Chen, Xiang Liu, Yan-Rui Liu, Shi-Lin Zhu
An updated review of the new hadron states
Review accepted by Reports on Progress in Physics, 179 pages, 87 figures, 15 tables
Rept. Prog. Phys. 86 (2023) no.2, 026201
10.1088/1361-6633/aca3b6
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
The past decades witnessed the golden era of hadron physics. Many excited open heavy flavor mesons and baryons have been observed since 2017. We shall provide an updated review of the recent experimental and theoretical progresses in this active field. Besides the conventional heavy hadrons, we shall also review the recently observed open heavy flavor tetraquark states $X(2900)$ and $T_{cc}^+(3875)$ as well as the hidden heavy flavor multiquark states $X(6900)$, $P_{cs}(4459)^0$, $Z_{cs}(3985)^-$, $Z_{cs}(4000)^+$, and $Z_{cs}(4220)^+$. We will also cover the recent progresses on the glueballs and light hybrid mesons, which are the direct manifestations of the non-Abelian $SU(3)$ gauge interaction of the Quantum Chromodynamics in the low-energy region.
[ { "created": "Wed, 6 Apr 2022 08:06:01 GMT", "version": "v1" }, { "created": "Sat, 19 Nov 2022 14:39:20 GMT", "version": "v2" } ]
2022-12-23
[ [ "Chen", "Hua-Xing", "" ], [ "Chen", "Wei", "" ], [ "Liu", "Xiang", "" ], [ "Liu", "Yan-Rui", "" ], [ "Zhu", "Shi-Lin", "" ] ]
The past decades witnessed the golden era of hadron physics. Many excited open heavy flavor mesons and baryons have been observed since 2017. We shall provide an updated review of the recent experimental and theoretical progresses in this active field. Besides the conventional heavy hadrons, we shall also review the recently observed open heavy flavor tetraquark states $X(2900)$ and $T_{cc}^+(3875)$ as well as the hidden heavy flavor multiquark states $X(6900)$, $P_{cs}(4459)^0$, $Z_{cs}(3985)^-$, $Z_{cs}(4000)^+$, and $Z_{cs}(4220)^+$. We will also cover the recent progresses on the glueballs and light hybrid mesons, which are the direct manifestations of the non-Abelian $SU(3)$ gauge interaction of the Quantum Chromodynamics in the low-energy region.
0808.1847
Robert Thorne S
R.S. Thorne, A.D. Martin, W.J. Stirling and G. Watt
Parton Distributions and QCD at LHCb
4 pages, 7 figures. To appear in the proceedings of the 16th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2008), London, England, 7-11 April 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the impact that can be made on our understanding of parton distributions (PDFs) and QCD from early measurements at the LHCb experiment. The high rapidity values make the experiment uniquely suited to a detailed study of small-x parton distributions and hence will make a significant contribution towards the clarification of both experimental and theoretical uncertainties on PDFs and their applications.
[ { "created": "Wed, 13 Aug 2008 15:11:42 GMT", "version": "v1" } ]
2008-08-14
[ [ "Thorne", "R. S.", "" ], [ "Martin", "A. D.", "" ], [ "Stirling", "W. J.", "" ], [ "Watt", "G.", "" ] ]
We consider the impact that can be made on our understanding of parton distributions (PDFs) and QCD from early measurements at the LHCb experiment. The high rapidity values make the experiment uniquely suited to a detailed study of small-x parton distributions and hence will make a significant contribution towards the clarification of both experimental and theoretical uncertainties on PDFs and their applications.
1212.5939
Apostolos Pilaftsis
Amon Ilakovac, Apostolos Pilaftsis and Luka Popov
Charged Lepton Flavour Violation in Supersymmetric Low-Scale Seesaw Models
28 pages, 11 figures, comment added to conclusions, version as to appear in Physical Review D
Phys. Rev. D87 (2013) 053014
10.1103/PhysRevD.87.053014
MAN/HEP/2012/22
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study charged lepton flavour violation in low-scale seesaw models of minimal supergravity, which realize large neutrino Yukawa couplings thanks to approximate lepton-number symmetries. There are two dominant sources of lepton flavour violation in such models. The first source originates from the usual soft supersymmetry-breaking sector, whilst the second one is entirely supersymmetric and comes from the supersymmetric neutrino Yukawa sector. Within the framework of minimal supergravity, we consider both sources of lepton flavour violation, soft and supersymmetric, and calculate a number of possible lepton-flavour-violating transitions, such as the photonic decays of muons and taus, mu -> e gamma, tau -> e gamma and tau -> mu gamma, their neutrinoless three-body decays, mu -> e e e, tau -> e e e, tau -> mu mu mu, tau -> e e mu and tau -> e mu mu, and the coherent mu -> e conversion in nuclei. After taking into account the exclusion bounds placed by present experiments of lepton flavour violation, we derive combined theoretical limits on the universal heavy Majorana mass scale mN and the light-to-heavy neutrino mixings. Supersymmetric low-scale seesaw models offer distinct correlated predictions for lepton-flavour-violating signatures, which might be discovered in current and projected experiments, such as MEG, COMET/PRISM, Mu2e, super-BELLE and LHCb.
[ { "created": "Mon, 24 Dec 2012 17:19:35 GMT", "version": "v1" }, { "created": "Fri, 4 Jan 2013 09:12:11 GMT", "version": "v2" }, { "created": "Sun, 13 Jan 2013 16:42:00 GMT", "version": "v3" }, { "created": "Thu, 28 Feb 2013 10:50:01 GMT", "version": "v4" } ]
2013-08-01
[ [ "Ilakovac", "Amon", "" ], [ "Pilaftsis", "Apostolos", "" ], [ "Popov", "Luka", "" ] ]
We study charged lepton flavour violation in low-scale seesaw models of minimal supergravity, which realize large neutrino Yukawa couplings thanks to approximate lepton-number symmetries. There are two dominant sources of lepton flavour violation in such models. The first source originates from the usual soft supersymmetry-breaking sector, whilst the second one is entirely supersymmetric and comes from the supersymmetric neutrino Yukawa sector. Within the framework of minimal supergravity, we consider both sources of lepton flavour violation, soft and supersymmetric, and calculate a number of possible lepton-flavour-violating transitions, such as the photonic decays of muons and taus, mu -> e gamma, tau -> e gamma and tau -> mu gamma, their neutrinoless three-body decays, mu -> e e e, tau -> e e e, tau -> mu mu mu, tau -> e e mu and tau -> e mu mu, and the coherent mu -> e conversion in nuclei. After taking into account the exclusion bounds placed by present experiments of lepton flavour violation, we derive combined theoretical limits on the universal heavy Majorana mass scale mN and the light-to-heavy neutrino mixings. Supersymmetric low-scale seesaw models offer distinct correlated predictions for lepton-flavour-violating signatures, which might be discovered in current and projected experiments, such as MEG, COMET/PRISM, Mu2e, super-BELLE and LHCb.
hep-ph/9409263
null
M.Baillargeon, G. Belanger and F. Boudjema
Extracting the Intermediate-Mass Higgs Resonance at Photon-Photon Colliders
39 pages, 14 encaps. figures, ENSLAPP-A-485/94, UdeM-GPP-TH-94-9 LaTeX. Full .ps file available via anonymous ftp at LPSVSH.LPS.UMONTREAL.CA as [ANONYMOUS.THEORIE.BELANGER]HRESONANCE.PS (1.2 Mb, uncompressed)
Phys.Rev. D51 (1995) 4712-4730
10.1103/PhysRevD.51.4712
null
hep-ph
null
We address the problem of how to extract the signal of a Higgs within the intermediate mass range at a photon-photon collider that has a wide energy spectrum. All backgrounds from two-jets production are included: direct, so-called resolved and twice-resolved as well as single $Z$ and $W$ production. Uncertainties in the evaluation of the QCD-initiated processes such as the choice of structure function and the issue of radiative corrections are discussed. We consider various combinations of the polarizations and invariant mass resolutions as well as jet-tagging strategies with different efficiencies. The analysis is based on an automatized technique that, given a specific detector and machine configuration, returns the optimal set of cuts corresponding to the best significance one may hope to achieve for each particular Higgs mass. We find that at a photon machine obtained from a 500GeV \epm\ linear collider with $\int\!{\cal L}=10$~fb$^{-1}$ it will be possible to extract a Higgs signal in the range 110--140~GeV, while with the same luminosity, a 350~GeV option not only extends the discovery limit down to 90~GeV but gives much better significance levels.
[ { "created": "Thu, 8 Sep 1994 19:34:04 GMT", "version": "v1" } ]
2009-10-28
[ [ "Baillargeon", "M.", "" ], [ "Belanger", "G.", "" ], [ "Boudjema", "F.", "" ] ]
We address the problem of how to extract the signal of a Higgs within the intermediate mass range at a photon-photon collider that has a wide energy spectrum. All backgrounds from two-jets production are included: direct, so-called resolved and twice-resolved as well as single $Z$ and $W$ production. Uncertainties in the evaluation of the QCD-initiated processes such as the choice of structure function and the issue of radiative corrections are discussed. We consider various combinations of the polarizations and invariant mass resolutions as well as jet-tagging strategies with different efficiencies. The analysis is based on an automatized technique that, given a specific detector and machine configuration, returns the optimal set of cuts corresponding to the best significance one may hope to achieve for each particular Higgs mass. We find that at a photon machine obtained from a 500GeV \epm\ linear collider with $\int\!{\cal L}=10$~fb$^{-1}$ it will be possible to extract a Higgs signal in the range 110--140~GeV, while with the same luminosity, a 350~GeV option not only extends the discovery limit down to 90~GeV but gives much better significance levels.
hep-ph/9408275
null
D. Choudhury, F. Eberlein, A. K\"onig, J. Louis, S. Pokorski
Constraints on non-universal soft terms from flavor changing neutral currents
15 pages (harvmac) and 5 figures (uuencoded), MPI-PhT/94-51
Phys.Lett.B342:180-188,1995
10.1016/0370-2693(94)01380-U
null
hep-ph
null
The smallness of flavor changing neutral currents constrains the soft parameter space of supersymmetric extensions of the Standard Model. These low energy constraints are translated to the soft parameter space generated at some high energy scale $\Mgut$. For gaugino masses larger than the scalar masses and non-universal $A$-terms the constraints are significantly diluted at $\Mgut$ and do allow for the possibility of non-universal scalar masses. The strongest constraints arise in the slepton sector of the theory.
[ { "created": "Thu, 11 Aug 1994 19:32:23 GMT", "version": "v1" }, { "created": "Wed, 19 Oct 1994 10:38:35 GMT", "version": "v2" } ]
2010-01-28
[ [ "Choudhury", "D.", "" ], [ "Eberlein", "F.", "" ], [ "König", "A.", "" ], [ "Louis", "J.", "" ], [ "Pokorski", "S.", "" ] ]
The smallness of flavor changing neutral currents constrains the soft parameter space of supersymmetric extensions of the Standard Model. These low energy constraints are translated to the soft parameter space generated at some high energy scale $\Mgut$. For gaugino masses larger than the scalar masses and non-universal $A$-terms the constraints are significantly diluted at $\Mgut$ and do allow for the possibility of non-universal scalar masses. The strongest constraints arise in the slepton sector of the theory.
2101.00037
Andreas Papaefstathiou
Andreas Papaefstathiou, Tania Robens, Gilberto Tetlalmatzi-Xolocotzi
Triple Higgs Boson Production at the Large Hadron Collider with Two Real Singlet Scalars
29 pages, 2 figures. Matches published version
JHEP 05 (2021) 193
10.1007/JHEP05(2021)193
SI-HEP-2020-34, RBI-ThPhys-2020-53
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the production of three Higgs bosons in the Two Real Singlet extension of the Standard Model, where the scalar sector is augmented by two additional real scalar fields which are singlets under the Standard Model gauge group. The model contains three neutral CP-even scalars, allowing for resonant production and asymmetric decay chains. We focus on the signature $p p\,\rightarrow\,h_3\,\rightarrow\,h_1\,h_2\,\rightarrow\,h_1\,h_1\,h_1$, where we identify $h_3$ as the heaviest scalar state, $h_2$ as the second heaviest and the lightest, $h_1$, as the Standard Model-like Higgs boson discovered by the Large Hadron Collider experiments. The dominant final state occurs when all three Higgs bosons decay to bottom-anti-bottom quark pairs, $h_1\,\rightarrow\,b\,\bar{b}$, leading to 6 $b$-jets. Taking into account all current theoretical and experimental constraints, we determine the discovery prospects for this channel in future runs of the Large Hadron Collider, as well as in the high-luminosity phase.
[ { "created": "Thu, 31 Dec 2020 19:07:22 GMT", "version": "v1" }, { "created": "Fri, 28 May 2021 20:39:05 GMT", "version": "v2" } ]
2021-06-01
[ [ "Papaefstathiou", "Andreas", "" ], [ "Robens", "Tania", "" ], [ "Tetlalmatzi-Xolocotzi", "Gilberto", "" ] ]
We investigate the production of three Higgs bosons in the Two Real Singlet extension of the Standard Model, where the scalar sector is augmented by two additional real scalar fields which are singlets under the Standard Model gauge group. The model contains three neutral CP-even scalars, allowing for resonant production and asymmetric decay chains. We focus on the signature $p p\,\rightarrow\,h_3\,\rightarrow\,h_1\,h_2\,\rightarrow\,h_1\,h_1\,h_1$, where we identify $h_3$ as the heaviest scalar state, $h_2$ as the second heaviest and the lightest, $h_1$, as the Standard Model-like Higgs boson discovered by the Large Hadron Collider experiments. The dominant final state occurs when all three Higgs bosons decay to bottom-anti-bottom quark pairs, $h_1\,\rightarrow\,b\,\bar{b}$, leading to 6 $b$-jets. Taking into account all current theoretical and experimental constraints, we determine the discovery prospects for this channel in future runs of the Large Hadron Collider, as well as in the high-luminosity phase.
hep-ph/0310254
Carl Shakin
Hu Li, C. M. Shakin, Qing Sun
Quark Model Calculations of Spectral Functions of Hadronic Current Correlation Functions at Finite Temperature
14 pages, 5 figures, revtex4
null
null
null
hep-ph
null
We calculate spectral functions associated with hadronic current correlation functions for vector and pseudoscalar currents at finite temperature. We make use of the Nambu--Jona--Lasinio (NJL) model with temperature-dependent coupling constants and temperature-dependent momentum cutoff parameters. At low energies, good fits are obtained for the spectral functions that were extracted from lattice data by means of the maximum entropy method (MEM). Our model has two parameters which are used to fix the magnitude and position of the large peak seen in the spectral functions. With those two parameters fixed, we obtain a satisfactory fit to the width of the peak. The model then also reproduces the energy of a second peak seen in the spectral functions. In the case of the pseudoscalar spectral function, the calculated peak is about 20 percent higher than that found for the spectral function obtained from the lattice data. However, it appears that the second peak is a lattice artifact [ P. Petreczky, private communication ] and our fit to the second peak may not be meaningful. We conclude that the NJL model may have a broader range of application than previously considered to be the case, if one allows for significant temperature dependence of the parameters of the model, as well as rather large values of the momentum cutoff parameter. Our treatment of temperature-dependent coupling constants and cutoff parameters is analogous to the procedure introduced by R. Casalbuoni, R. Gatto, G. Nardulli, and M. Ruggieri, [ Phys. Rev. D \textbf{68}, 034024 (2003) ], who make use of the NJL model at finite density and find that they need to use the density-dependent coupling constants and density -dependent cutoff parameters to study matter at high density.
[ { "created": "Tue, 21 Oct 2003 15:21:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Li", "Hu", "" ], [ "Shakin", "C. M.", "" ], [ "Sun", "Qing", "" ] ]
We calculate spectral functions associated with hadronic current correlation functions for vector and pseudoscalar currents at finite temperature. We make use of the Nambu--Jona--Lasinio (NJL) model with temperature-dependent coupling constants and temperature-dependent momentum cutoff parameters. At low energies, good fits are obtained for the spectral functions that were extracted from lattice data by means of the maximum entropy method (MEM). Our model has two parameters which are used to fix the magnitude and position of the large peak seen in the spectral functions. With those two parameters fixed, we obtain a satisfactory fit to the width of the peak. The model then also reproduces the energy of a second peak seen in the spectral functions. In the case of the pseudoscalar spectral function, the calculated peak is about 20 percent higher than that found for the spectral function obtained from the lattice data. However, it appears that the second peak is a lattice artifact [ P. Petreczky, private communication ] and our fit to the second peak may not be meaningful. We conclude that the NJL model may have a broader range of application than previously considered to be the case, if one allows for significant temperature dependence of the parameters of the model, as well as rather large values of the momentum cutoff parameter. Our treatment of temperature-dependent coupling constants and cutoff parameters is analogous to the procedure introduced by R. Casalbuoni, R. Gatto, G. Nardulli, and M. Ruggieri, [ Phys. Rev. D \textbf{68}, 034024 (2003) ], who make use of the NJL model at finite density and find that they need to use the density-dependent coupling constants and density -dependent cutoff parameters to study matter at high density.