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/9708310 | Wolfgang Kilian | E. Boos, H.-J. He, W. Kilian, A. Pukhov, C.-P. Yuan, and P.M. Zerwas | Strongly Interacting Vector Bosons at TeV e+-e- Linear Colliders | 40 pages, LaTeX2e, uses feynmp.sty [included]. Improvements in text,
minor typos corrected | Phys.Rev.D57:1553,1998 | 10.1103/PhysRevD.57.1553 | DESY-96-256 | hep-ph | null | In the absence of light Higgs bosons, the W and Z bosons become strongly
interacting particles at energies of about 1 TeV. If the longitudinal W,Z
components are generated by Goldstone modes associated with spontaneous
symmetry breaking in a new strong interaction theory, the quasi-elastic W,Z
scattering amplitudes can be predicted as a systematic chiral expansion in the
energy. We study the potential of TeV e+e- and e-e- linear colliders in
investigating these scattering processes. We estimate the accuracy with which
the coefficients of the chiral expansion can be measured in a multi-parameter
analysis. The measurements will provide us with a quantitative test of the
dynamics underlying the W,Z interactions.
| [
{
"created": "Mon, 11 Aug 1997 21:25:54 GMT",
"version": "v1"
},
{
"created": "Mon, 15 Dec 1997 10:47:09 GMT",
"version": "v2"
}
] | 2011-07-19 | [
[
"Boos",
"E.",
""
],
[
"He",
"H. -J.",
""
],
[
"Kilian",
"W.",
""
],
[
"Pukhov",
"A.",
""
],
[
"Yuan",
"C. -P.",
""
],
[
"Zerwas",
"P. M.",
""
]
] | In the absence of light Higgs bosons, the W and Z bosons become strongly interacting particles at energies of about 1 TeV. If the longitudinal W,Z components are generated by Goldstone modes associated with spontaneous symmetry breaking in a new strong interaction theory, the quasi-elastic W,Z scattering amplitudes can be predicted as a systematic chiral expansion in the energy. We study the potential of TeV e+e- and e-e- linear colliders in investigating these scattering processes. We estimate the accuracy with which the coefficients of the chiral expansion can be measured in a multi-parameter analysis. The measurements will provide us with a quantitative test of the dynamics underlying the W,Z interactions. |
1612.02267 | Dmitry Zhuridov Dr. | Dmitry Zhuridov | Excited lepton baryogenesis | 5 pages, 3 figures. v2: References and comments added. Proceedings to
the conference "Advances in Dark Matter and Particle Physics", Messina,
Italy, October 24-27, 2016 | null | 10.1051/epjconf/201714201030 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The excited leptons that share the quantum numbers with the Standard Model
leptons but have larger masses are widespread in many promising new physics
theories. A subclass of excited leptons that at low energies interact with the
SM fermions dominantly through the effective coupling to lepton and
fermion-antifermion pair can be referred as leptomesons. I introduce possible
generation of the baryon asymmetry of the universe using these new particles.
The discussed baryogenesis mechanisms do not contradict to the small neutrino
masses and the proton stability, and can be interesting for the collider
experiments.
| [
{
"created": "Wed, 7 Dec 2016 14:44:01 GMT",
"version": "v1"
},
{
"created": "Thu, 15 Dec 2016 16:18:45 GMT",
"version": "v2"
}
] | 2017-04-26 | [
[
"Zhuridov",
"Dmitry",
""
]
] | The excited leptons that share the quantum numbers with the Standard Model leptons but have larger masses are widespread in many promising new physics theories. A subclass of excited leptons that at low energies interact with the SM fermions dominantly through the effective coupling to lepton and fermion-antifermion pair can be referred as leptomesons. I introduce possible generation of the baryon asymmetry of the universe using these new particles. The discussed baryogenesis mechanisms do not contradict to the small neutrino masses and the proton stability, and can be interesting for the collider experiments. |
hep-ph/9610545 | Rainer Plaga | R. Plaga (Max-Planck-Institut fuer Physik) | A demonstration that the observed neutrinos are not Majorana particles | This manuscript is incorrect, and is replaced by a completely
rewritten version hep-ph/0108052. Following the advice of arXiv.org I leave
the original version on the server. See http://hegra1.mppmu.mpg.de/majorana
for further information | null | null | null | hep-ph | null | Please see revised version hep-ph/0108052. The ps version of the manuscript
contains the original abstract and body.
| [
{
"created": "Wed, 30 Oct 1996 18:20:05 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Apr 1997 11:46:49 GMT",
"version": "v2"
},
{
"created": "Mon, 6 Aug 2001 10:08:48 GMT",
"version": "v3"
}
] | 2008-02-03 | [
[
"Plaga",
"R.",
"",
"Max-Planck-Institut fuer Physik"
]
] | Please see revised version hep-ph/0108052. The ps version of the manuscript contains the original abstract and body. |
hep-ph/9610263 | Edward Sarkisyan | E.K.G. Sarkisyan (Tel Aviv University), L.K. Gelovani, G.L.
Gogiberidze (JINR) | On Dynamics of Fractality in Central C-Cu Collisions at 4.5A Gev/c | 1+8 pages, 6 figures, LaTeX. Talk given by E. Sarkisyan at the 7th
International Workshop on Multiparticle Dynamics, ``Correlations and
Fluctuations'' Nijmegen, The Netherlands, June 30 - July 6, 1996. To appear
in the Proceedings (World Scientific, Singapore, 1997) | null | null | TAUP 2370-96 | hep-ph hep-ex | null | Fractal structure of charged particle distributions in the pseudorapidity and
transverse momentum in central C-Cu collisions at 4.5A GeV/c is studied by
means of intermittency approach and multifractal analysis. The modifications to
take into account statistical bias are applied. Intermittency study in the
pseudorapidity phase space indicates a non-thermal phase transition and
different regimes of multiparticle production. Multifractality is observed
within the both methods applied. The interrelation of the methods using the
effective average multiplicity approach is studied. The findings support the
idea of statistical significance of influence of finite multiplicities. In the
transverse momentum spectrum no dynamical fluctuations are found.
| [
{
"created": "Sun, 6 Oct 1996 19:03:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Sarkisyan",
"E. K. G.",
"",
"Tel Aviv University"
],
[
"Gelovani",
"L. K.",
"",
"JINR"
],
[
"Gogiberidze",
"G. L.",
"",
"JINR"
]
] | Fractal structure of charged particle distributions in the pseudorapidity and transverse momentum in central C-Cu collisions at 4.5A GeV/c is studied by means of intermittency approach and multifractal analysis. The modifications to take into account statistical bias are applied. Intermittency study in the pseudorapidity phase space indicates a non-thermal phase transition and different regimes of multiparticle production. Multifractality is observed within the both methods applied. The interrelation of the methods using the effective average multiplicity approach is studied. The findings support the idea of statistical significance of influence of finite multiplicities. In the transverse momentum spectrum no dynamical fluctuations are found. |
hep-ph/0212159 | Pavel Nadolsky | F. Landry, R. Brock, P.M. Nadolsky, and C.-P. Yuan | Tevatron Run-1 Z Boson Data and Collins-Soper-Sterman Resummation
Formalism | Published version; minor modifications, three references added; 19
pages, 7 figures | Phys.Rev.D67:073016,2003 | 10.1103/PhysRevD.67.073016 | null | hep-ph | null | We examine the effect of the Z-boson transverse momentum distribution
measured at the Run-1 of the Tevatron on the nonperturbative function of the
Collins-Soper-Sterman (CSS) formalism, which resums large logarithmic terms
from multiple soft gluon emission in hadron collisions. The inclusion of the
Tevatron Run-1 Z-boson data strongly favors a Gaussian form of the CSS
nonperturbative function, when combined with the other low energy Drell-Yan
data in a global fit.
| [
{
"created": "Wed, 11 Dec 2002 17:12:00 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Apr 2003 00:58:03 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Landry",
"F.",
""
],
[
"Brock",
"R.",
""
],
[
"Nadolsky",
"P. M.",
""
],
[
"Yuan",
"C. -P.",
""
]
] | We examine the effect of the Z-boson transverse momentum distribution measured at the Run-1 of the Tevatron on the nonperturbative function of the Collins-Soper-Sterman (CSS) formalism, which resums large logarithmic terms from multiple soft gluon emission in hadron collisions. The inclusion of the Tevatron Run-1 Z-boson data strongly favors a Gaussian form of the CSS nonperturbative function, when combined with the other low energy Drell-Yan data in a global fit. |
hep-ph/0010117 | Kaustubh Agashe | Kaustubh Agashe, Guo-Hong Wu (ITS, University of Oregon) | Remarks on models with singlet neutrino in large extra dimensions | Revised version. Discussion of Supernova constraint expanded with
added reference. LaTeX, 14 pages | Phys.Lett. B498 (2001) 230-236 | 10.1016/S0370-2693(00)01400-3 | OITS-696 | hep-ph | null | Small Dirac masses for neutrinos are natural in models with singlet fermions
in large extra dimensions with quantum gravity scale M_{\ast} \sim 1- 100 TeV.
We study two modifications of the minimal model in order to obtain the mass
scale relevant for atmospheric neutrino oscillations with at most O(1)
higher-dimensional Yukawa couplings and with M_{\ast} \sim a few TeV. 1) In
models with singlet fermions in smaller number of extra dimensions than
gravity, we find that the effects on BR (\mu \to e \gamma) and on
charged-current universality in \pi^- \to e \bar{\nu}, \mu \bar{\nu} decays are
suppressed as compared to that in the minimal model with neutrino and gravity
in the same space. 2) If small Dirac masses for the singlets are added along
with lepton number violating couplings, then the mass scales and mixing angles
for neutrino oscillations can be different from those relevant for \mu \to e
\gamma and \pi^- \to e \bar{\nu}, \mu \bar{\nu}. Thus, in both modified models
the constraints on M_{\ast} from BR (\mu \to e \gamma) and \pi^- \to e
\bar{\nu}, \mu \bar{\nu} decays can be significantly relaxed. Furthermore,
constraints from supernova 1987a strongly disfavor oscillations of active
neutrinos to sterile neutrinos in both the minimal and the modified models.
| [
{
"created": "Wed, 11 Oct 2000 22:51:27 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Dec 2000 02:39:10 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Agashe",
"Kaustubh",
"",
"ITS, University of Oregon"
],
[
"Wu",
"Guo-Hong",
"",
"ITS, University of Oregon"
]
] | Small Dirac masses for neutrinos are natural in models with singlet fermions in large extra dimensions with quantum gravity scale M_{\ast} \sim 1- 100 TeV. We study two modifications of the minimal model in order to obtain the mass scale relevant for atmospheric neutrino oscillations with at most O(1) higher-dimensional Yukawa couplings and with M_{\ast} \sim a few TeV. 1) In models with singlet fermions in smaller number of extra dimensions than gravity, we find that the effects on BR (\mu \to e \gamma) and on charged-current universality in \pi^- \to e \bar{\nu}, \mu \bar{\nu} decays are suppressed as compared to that in the minimal model with neutrino and gravity in the same space. 2) If small Dirac masses for the singlets are added along with lepton number violating couplings, then the mass scales and mixing angles for neutrino oscillations can be different from those relevant for \mu \to e \gamma and \pi^- \to e \bar{\nu}, \mu \bar{\nu}. Thus, in both modified models the constraints on M_{\ast} from BR (\mu \to e \gamma) and \pi^- \to e \bar{\nu}, \mu \bar{\nu} decays can be significantly relaxed. Furthermore, constraints from supernova 1987a strongly disfavor oscillations of active neutrinos to sterile neutrinos in both the minimal and the modified models. |
1312.1228 | Elvira Gamiz | A. Bazavov, C. Bernard, C. Bouchard, C. DeTar, D. Du, A.X. El-Khadra,
J. Foley, E.D. Freeland, E. G\'amiz, Steven Gottlieb, U.M. Heller, J. Kim,
A.S. Kronfeld, J. Laiho, L. Levkova, P.B. Mackenzie, E.T. Neil, M.B. Oktay,
Si-Wei Qiu, J.N. Simone, R. Sugar, D. Toussaint, R.S. Van de Water, Ran Zhou | Determination of $|V_{us}|$ from a lattice-QCD calculation of the
$K\to\pi\ell\nu$ semileptonic form factor with physical quark masses | 6 pages, 2 figures; version published in PRL | Phys. Rev. Lett. 112, 112001 (2014) | 10.1103/PhysRevLett.112.112001 | null | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We calculate the kaon semileptonic form factor $f_+(0)$ from lattice QCD,
working, for the first time, at the physical light-quark masses. We use gauge
configurations generated by the MILC collaboration with $N_f=2+1+1$ flavors of
sea quarks, which incorporate the effects of dynamical charm quarks as well as
those of up, down, and strange. We employ data at three lattice spacings to
extrapolate to the continuum limit. Our result, $f_+(0) = 0.9704(32)$, where
the error is the total statistical plus systematic uncertainty added in
quadrature, is the most precise determination to date. Combining our result
with the latest experimental measurements of $K$ semileptonic decays, one
obtains the Cabibbo-Kobayashi-Maskawa matrix element
$|V_{us}|=0.22290(74)(52)$, where the first error is from $f_+(0)$ and the
second one is from experiment. In the first-row test of
Cabibbo-Kobayashi-Maskawa unitarity, the error stemming from $|V_{us}|$ is now
comparable to that from $|V_{ud}|$.
| [
{
"created": "Wed, 4 Dec 2013 16:11:34 GMT",
"version": "v1"
},
{
"created": "Sun, 17 Aug 2014 15:13:11 GMT",
"version": "v2"
}
] | 2014-08-19 | [
[
"Bazavov",
"A.",
""
],
[
"Bernard",
"C.",
""
],
[
"Bouchard",
"C.",
""
],
[
"DeTar",
"C.",
""
],
[
"Du",
"D.",
""
],
[
"El-Khadra",
"A. X.",
""
],
[
"Foley",
"J.",
""
],
[
"Freeland",
"E. D.",
""
],
[
"Gámiz",
"E.",
""
],
[
"Gottlieb",
"Steven",
""
],
[
"Heller",
"U. M.",
""
],
[
"Kim",
"J.",
""
],
[
"Kronfeld",
"A. S.",
""
],
[
"Laiho",
"J.",
""
],
[
"Levkova",
"L.",
""
],
[
"Mackenzie",
"P. B.",
""
],
[
"Neil",
"E. T.",
""
],
[
"Oktay",
"M. B.",
""
],
[
"Qiu",
"Si-Wei",
""
],
[
"Simone",
"J. N.",
""
],
[
"Sugar",
"R.",
""
],
[
"Toussaint",
"D.",
""
],
[
"Van de Water",
"R. S.",
""
],
[
"Zhou",
"Ran",
""
]
] | We calculate the kaon semileptonic form factor $f_+(0)$ from lattice QCD, working, for the first time, at the physical light-quark masses. We use gauge configurations generated by the MILC collaboration with $N_f=2+1+1$ flavors of sea quarks, which incorporate the effects of dynamical charm quarks as well as those of up, down, and strange. We employ data at three lattice spacings to extrapolate to the continuum limit. Our result, $f_+(0) = 0.9704(32)$, where the error is the total statistical plus systematic uncertainty added in quadrature, is the most precise determination to date. Combining our result with the latest experimental measurements of $K$ semileptonic decays, one obtains the Cabibbo-Kobayashi-Maskawa matrix element $|V_{us}|=0.22290(74)(52)$, where the first error is from $f_+(0)$ and the second one is from experiment. In the first-row test of Cabibbo-Kobayashi-Maskawa unitarity, the error stemming from $|V_{us}|$ is now comparable to that from $|V_{ud}|$. |
hep-ph/0002268 | Vladislav Korotkov | V. A. Korotkov, W.-D. Nowak, K. A. Oganessyan | Transversity Distribution and Polarized Fragmentation Function from
Semi-inclusive Pion Electroproduction | 5 pages, 5 figures, revised version as will be published in EPJ C | Eur.Phys.J.C18:639-644,2001 | 10.1007/s100520100564 | DESY 99-176 | hep-ph | null | A method is discussed to determine the hitherto unknown u-quark transversity
distribution from a planned HERMES measurement of a single-spin asymmetry in
semi-inclusive pion electroproduction off a transversely polarized target.
Assuming u-quark dominance, the measurement yields the shapes of the
transversity distribution and of the ratio of a polarized and the unpolarized
u-quark fragmentation functions. The unknown relative normalization can be
obtained by identifying the transversity distribution with the well-known
helicity distribution at large x. The systematic uncertainty of the method is
dominated by the assumption of u-quark dominance.
| [
{
"created": "Fri, 25 Feb 2000 14:13:34 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jan 2001 13:00:04 GMT",
"version": "v2"
}
] | 2009-01-07 | [
[
"Korotkov",
"V. A.",
""
],
[
"Nowak",
"W. -D.",
""
],
[
"Oganessyan",
"K. A.",
""
]
] | A method is discussed to determine the hitherto unknown u-quark transversity distribution from a planned HERMES measurement of a single-spin asymmetry in semi-inclusive pion electroproduction off a transversely polarized target. Assuming u-quark dominance, the measurement yields the shapes of the transversity distribution and of the ratio of a polarized and the unpolarized u-quark fragmentation functions. The unknown relative normalization can be obtained by identifying the transversity distribution with the well-known helicity distribution at large x. The systematic uncertainty of the method is dominated by the assumption of u-quark dominance. |
hep-ph/0307014 | Gino Isidori | Gino Isidori | K -> pi nu nu-bar decays and CKM fits | Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP
Durham, April 2003 (eConf C0304052). 5 pages LaTeX, 4 eps figures (v2:
numerical errors corrected) | eConf C0304052 (2003) WG304 | null | null | hep-ph | null | After a brief introduction to the so-called flavour problem, we discuss the
role of K -> pi nu nu-bar decays in shedding new light on this issue. In
particular, we review the theoretical uncertainties in predicting B(K -> pi nu
nu-bar) within the SM, the sensitivity of these observables to New Physics
scenarios, and the status of their experimental determination.
| [
{
"created": "Tue, 1 Jul 2003 10:35:42 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Jul 2003 18:13:38 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Isidori",
"Gino",
""
]
] | After a brief introduction to the so-called flavour problem, we discuss the role of K -> pi nu nu-bar decays in shedding new light on this issue. In particular, we review the theoretical uncertainties in predicting B(K -> pi nu nu-bar) within the SM, the sensitivity of these observables to New Physics scenarios, and the status of their experimental determination. |
hep-ph/9812331 | Avtandil Tkabladze | J. Bl\"umlein and A. Tkabladze | Target Mass Corrections to the Spin-dependent Structure Functions | 2 pages LATEX, contract number added | J.Phys.G25:1553-1554,1999 | 10.1088/0954-3899/25/7/350 | null | hep-ph | null | The target mass corrections to the twist-2 contributions of the
spin-dependent structure functions are calculated using operator product
expansion in lowest order in QCD. The influence of such corrections to the
different relations between the structure functions is considered.
| [
{
"created": "Fri, 11 Dec 1998 10:44:09 GMT",
"version": "v1"
},
{
"created": "Thu, 31 Aug 2000 15:54:54 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Blümlein",
"J.",
""
],
[
"Tkabladze",
"A.",
""
]
] | The target mass corrections to the twist-2 contributions of the spin-dependent structure functions are calculated using operator product expansion in lowest order in QCD. The influence of such corrections to the different relations between the structure functions is considered. |
hep-ph/9608471 | Reinhard Alkofer | R. Alkofer, A. Hauck and L. von Smekal | The Strong Running Coupling from an Approximate Gluon Dyson-Schwinger
Equation | 4 pages, 3 figures, Contribution to the Workshop ''Quark Confinement
and the Hadron Spectrum II'', Como, Italy, June 26--29, 1996, to appear in
the Proceedings, ed. Nora Brambilla, World Scientific | null | null | UNITU-THEP-13/1996, ANL-PHY-8477-TH-96 | hep-ph | null | Using Mandelstam's approximation to the gluon Dyson-Schwinger equation we
calculate the gluon self-energy in a renormalisation group invariant fashion.
We obtain a non-perturbative $\beta $ function. The scaling behaviour near the
ultraviolet stable fixed point is in good agreement with perturbative QCD. No
further fixed point for positive values of the coupling is found: $\alpha_S$
increases without bound in the infrared.
| [
{
"created": "Wed, 28 Aug 1996 14:35:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Alkofer",
"R.",
""
],
[
"Hauck",
"A.",
""
],
[
"von Smekal",
"L.",
""
]
] | Using Mandelstam's approximation to the gluon Dyson-Schwinger equation we calculate the gluon self-energy in a renormalisation group invariant fashion. We obtain a non-perturbative $\beta $ function. The scaling behaviour near the ultraviolet stable fixed point is in good agreement with perturbative QCD. No further fixed point for positive values of the coupling is found: $\alpha_S$ increases without bound in the infrared. |
hep-ph/9811442 | Jogesh Pati | J. C. Pati | With Neutrino Masses Revealed, Proton Decay is the Missing Link | Invited talk at the Abdus Salam Memorial meetimg, Trieste, November,
1997; latex, 34 pages | Int.J.Mod.Phys.A14:2949-2976,1999 | 10.1142/S0217751X99001433 | null | hep-ph | null | By way of paying tribute to Abdus Salam, I recall the ideas of higher
unification that he and I initiated. I discuss the current status of those
ideas in the light of recent developments, including those of: (a) gauge
coupling unification, (b) discovery of neutrino-oscillation at SuperKamiokande,
and (c) ongoing searches for proton decay. It is remarked that the mass of
$\nu_\tau$ ($\sim$ 1/20 eV) suggested by the SuperK result seems to provide
clear support for an underlying unity of forces based on the ideas of (i)
SU(4)-color, (ii) left-right symmetry and (iii) supersymmetry. The change in
perspective, pertaining to both gauge coupling unification and proton decay,
brought forth by supersymmetry and superstrings is presented. The beneficial
roles of string- symmetries in addressing certain naturalness problems of
supersymmetry, including that of rapid proton decay, are noted. In the last
section, attention is drawn to the recent joint works with K. Babu and F.
Wilczek, where the influence of neutrino masses and thus of the new SuperK
result on proton decay are noted. In this context, it is remarked that with
neutrino masses and coupling unification revealed, the discovery of proton
decay, that remains as the missing link, should not be far behind.
| [
{
"created": "Mon, 23 Nov 1998 17:13:57 GMT",
"version": "v1"
}
] | 2010-12-09 | [
[
"Pati",
"J. C.",
""
]
] | By way of paying tribute to Abdus Salam, I recall the ideas of higher unification that he and I initiated. I discuss the current status of those ideas in the light of recent developments, including those of: (a) gauge coupling unification, (b) discovery of neutrino-oscillation at SuperKamiokande, and (c) ongoing searches for proton decay. It is remarked that the mass of $\nu_\tau$ ($\sim$ 1/20 eV) suggested by the SuperK result seems to provide clear support for an underlying unity of forces based on the ideas of (i) SU(4)-color, (ii) left-right symmetry and (iii) supersymmetry. The change in perspective, pertaining to both gauge coupling unification and proton decay, brought forth by supersymmetry and superstrings is presented. The beneficial roles of string- symmetries in addressing certain naturalness problems of supersymmetry, including that of rapid proton decay, are noted. In the last section, attention is drawn to the recent joint works with K. Babu and F. Wilczek, where the influence of neutrino masses and thus of the new SuperK result on proton decay are noted. In this context, it is remarked that with neutrino masses and coupling unification revealed, the discovery of proton decay, that remains as the missing link, should not be far behind. |
hep-ph/9907381 | Robertus Potting | A. Kovner, A. Krasnitz and R. Potting | Sphaleron Transition Rate in Presence of Dynamical Fermions | 20 pages, 7 figures, LaTeX, psfig | Phys.Rev. D61 (2000) 025009 | 10.1103/PhysRevD.61.025009 | UAlg/TP/98-3 | hep-ph | null | We investigate the effect of dynamical fermions on the sphaleron transition
rate at finite temperature for the Abelian Higgs model in one spatial
dimension. The fermion degrees of freedom are included through bosonization.
Using a numerical simulation, we find that massless fermions do not change the
rate within the measurement accuracy. Surprisingly, the exponential dependence
of the sphaleron energy on the Yukawa coupling is not borne out by the
transition rate, which shows a very weak dependence on the fermion mass.
| [
{
"created": "Thu, 15 Jul 1999 16:14:25 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Kovner",
"A.",
""
],
[
"Krasnitz",
"A.",
""
],
[
"Potting",
"R.",
""
]
] | We investigate the effect of dynamical fermions on the sphaleron transition rate at finite temperature for the Abelian Higgs model in one spatial dimension. The fermion degrees of freedom are included through bosonization. Using a numerical simulation, we find that massless fermions do not change the rate within the measurement accuracy. Surprisingly, the exponential dependence of the sphaleron energy on the Yukawa coupling is not borne out by the transition rate, which shows a very weak dependence on the fermion mass. |
hep-ph/0003102 | Hans-Peter Nilles | Hans Peter Nilles | Remarks on anomalous U(1) symmetries in string theory | 7 pages, Latex, Contribution to the Proceedings of COSMO-99,
International Workshop on Particle Physics and the Early Universe, Trieste | null | null | null | hep-ph | null | Anomalous U(1) gauge symmetries appear frequently both in heterotic and type
I/type II string theory. In the heterotic case we find at most a single
anomalous U(1), while in open string theories several such symmetries can
appear. We review the properties of the anomalous gauge bosons, the appearance
of Fayet-Iliopoulos terms and the concept of heterotic-type I duality.
Phenomenological applications of these symmetries might be different in the
type I/type II case compared to the heterotic one.
| [
{
"created": "Fri, 10 Mar 2000 16:10:21 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Nilles",
"Hans Peter",
""
]
] | Anomalous U(1) gauge symmetries appear frequently both in heterotic and type I/type II string theory. In the heterotic case we find at most a single anomalous U(1), while in open string theories several such symmetries can appear. We review the properties of the anomalous gauge bosons, the appearance of Fayet-Iliopoulos terms and the concept of heterotic-type I duality. Phenomenological applications of these symmetries might be different in the type I/type II case compared to the heterotic one. |
0810.1446 | Frans Klinkhamer | F.R. Klinkhamer | New indirect bounds on Lorentz violation in the photon sector | Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 4 pages,
LaTeX, 2 eps figures. v3: references added | null | null | KA-TP-25-2008 | hep-ph astro-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Direct laboratory bounds on the 9 nonbirefringent Lorentz-violating
dimensionless parameters of modified-Maxwell theory range from the 10^{-7}
level to the 10^{-16} level. The detection of air showers initiated by charged
primaries (ultrahigh-energy cosmic-rays) and neutral primaries (TeV gamma-rays)
allows us to obtain new indirect bounds ranging from the 10^{-15} level to the
10^{-19} level. Possible physics implications are briefly discussed.
| [
{
"created": "Wed, 8 Oct 2008 18:04:12 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Oct 2008 17:28:49 GMT",
"version": "v2"
},
{
"created": "Mon, 27 Oct 2008 10:10:34 GMT",
"version": "v3"
}
] | 2008-10-28 | [
[
"Klinkhamer",
"F. R.",
""
]
] | Direct laboratory bounds on the 9 nonbirefringent Lorentz-violating dimensionless parameters of modified-Maxwell theory range from the 10^{-7} level to the 10^{-16} level. The detection of air showers initiated by charged primaries (ultrahigh-energy cosmic-rays) and neutral primaries (TeV gamma-rays) allows us to obtain new indirect bounds ranging from the 10^{-15} level to the 10^{-19} level. Possible physics implications are briefly discussed. |
hep-ph/0404263 | Xiaojun Bi | Xiao-Jun Bi, Jian-Xiong Wang, Chao Zhang, Xinmin Zhang | Phenomenology of quintessino dark matter -- Production of NLSP particles | 16 pages, 5 figures, a new section about NLSP stau is added,
references added | Phys.Rev. D70 (2004) 123512 | 10.1103/PhysRevD.70.123512 | null | hep-ph | null | In the model of quintessino as dark matter particle, the dark matter and dark
energy are unified in one superfield, where the dynamics of the Quintessence
drives the Universe acceleration and its superpartner, quintessino, makes up
the dark matter of the Universe. This scenario predicts the existence of long
lived $\tilde{\tau}$ as the next lightest supersymmetric particle. In this
paper we study the possibility of detecting $\tilde{\tau}$ produced by the high
energy cosmic neutrinos interacting with the earth matter. By a detailed
calculation we find that the event rate is one to several hundred per year at a
detector with effective area of $1 km^2$. The study in this paper can be also
applied for models of gravitino or axino dark matter particles.
| [
{
"created": "Thu, 29 Apr 2004 09:29:45 GMT",
"version": "v1"
},
{
"created": "Wed, 29 Sep 2004 06:34:24 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Bi",
"Xiao-Jun",
""
],
[
"Wang",
"Jian-Xiong",
""
],
[
"Zhang",
"Chao",
""
],
[
"Zhang",
"Xinmin",
""
]
] | In the model of quintessino as dark matter particle, the dark matter and dark energy are unified in one superfield, where the dynamics of the Quintessence drives the Universe acceleration and its superpartner, quintessino, makes up the dark matter of the Universe. This scenario predicts the existence of long lived $\tilde{\tau}$ as the next lightest supersymmetric particle. In this paper we study the possibility of detecting $\tilde{\tau}$ produced by the high energy cosmic neutrinos interacting with the earth matter. By a detailed calculation we find that the event rate is one to several hundred per year at a detector with effective area of $1 km^2$. The study in this paper can be also applied for models of gravitino or axino dark matter particles. |
hep-ph/0611347 | C. A. Dominguez | C.A. Dominguez, K. Schilcher | QCD vacuum condensates from tau-lepton decay data | Revised version: minor explanatory sentences added. No change in
results nor figures | JHEP 0701:093,2007 | 10.1088/1126-6708/2007/01/093 | UCT-TP-266/06 | hep-ph | null | The QCD vacuum condensates in the Operator Product Expansion are extracted
from the final ALEPH data on vector and axial-vector spectral functions from
$\tau$-decay. Weighted Finite Energy Sum Rules are employed in the framework of
both Fixed Order and Contour Improved Perturbation Theory. An overall
consistent picture satisfying chirality constraints can be achieved only for
values of the QCD scale below some critical value $\Lambda\simeq350 {MeV}$. For
larger values of $\Lambda$, perturbation theory overwhelms the power
corrections. A strong correlation is then found between $\Lambda$ and the
resulting values of the condensates. Reasonable accuracy is obtained up to
dimension $d=8$, beyond which no meaningful extraction is possible.
| [
{
"created": "Tue, 28 Nov 2006 09:13:10 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Jan 2007 11:45:48 GMT",
"version": "v2"
}
] | 2010-10-27 | [
[
"Dominguez",
"C. A.",
""
],
[
"Schilcher",
"K.",
""
]
] | The QCD vacuum condensates in the Operator Product Expansion are extracted from the final ALEPH data on vector and axial-vector spectral functions from $\tau$-decay. Weighted Finite Energy Sum Rules are employed in the framework of both Fixed Order and Contour Improved Perturbation Theory. An overall consistent picture satisfying chirality constraints can be achieved only for values of the QCD scale below some critical value $\Lambda\simeq350 {MeV}$. For larger values of $\Lambda$, perturbation theory overwhelms the power corrections. A strong correlation is then found between $\Lambda$ and the resulting values of the condensates. Reasonable accuracy is obtained up to dimension $d=8$, beyond which no meaningful extraction is possible. |
hep-ph/9705253 | null | G. Buchalla, G. Isidori and S.-J. Rey | Corrections of Order $\Lambda^2_{QCD}/m^2_c$ to Inclusive Rare B Decays | Latex, 15 pages, 3 figures (included) | Nucl.Phys.B511:594-610,1998 | 10.1016/S0550-3213(97)00674-3 | IASSNS-HEP 97/41, SLAC-PUB-7448 | hep-ph | null | We calculate nonperturbative ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to
the dilepton invariant mass spectrum and the forward-backward charge asymmetry
in $B\to X_se^+e^-$ decay using a heavy quark expansion approach. The method
has recently been used to estimate long-distance effects in $B\to X_s\gamma$.
We generalize this analysis to the case of nonvanishing photon invariant mass,
$q^2\not= 0$, relevant for the rare decay mode $B\to X_se^+e^-$. In the
phenomenologically interesting $q^2$ region away from the $c\bar c$ resonances,
the heavy quark expansion approach should provide a reasonable description of
possible nonperturbative corrections. In particular this picture is preferable
to the model-dependent approach relying on the tails of Breit-Wigner
resonances, which has been employed so far in the literature to account for
these effects. We find that the ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections
to the dilepton invariant mass spectrum and to the forward-backward asymmetry
in $B\to X_se^+e^-$ amount to several percent at most for $q^2/m^2_b < 0.3$ and
$q^2/m^2_b > 0.6$. The ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ correction to the
$B\to X_s\gamma$ decay rate is also computed and found to be +3%, which agrees
in magnitude with previous calculations. Finally, we comment on long-distance
effects in $B\to X_s\nu\bar\nu$, which in this case are extremely suppressed
due to the absence of virtual photon contributions.
| [
{
"created": "Wed, 7 May 1997 05:51:31 GMT",
"version": "v1"
}
] | 2016-09-06 | [
[
"Buchalla",
"G.",
""
],
[
"Isidori",
"G.",
""
],
[
"Rey",
"S. -J.",
""
]
] | We calculate nonperturbative ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to the dilepton invariant mass spectrum and the forward-backward charge asymmetry in $B\to X_se^+e^-$ decay using a heavy quark expansion approach. The method has recently been used to estimate long-distance effects in $B\to X_s\gamma$. We generalize this analysis to the case of nonvanishing photon invariant mass, $q^2\not= 0$, relevant for the rare decay mode $B\to X_se^+e^-$. In the phenomenologically interesting $q^2$ region away from the $c\bar c$ resonances, the heavy quark expansion approach should provide a reasonable description of possible nonperturbative corrections. In particular this picture is preferable to the model-dependent approach relying on the tails of Breit-Wigner resonances, which has been employed so far in the literature to account for these effects. We find that the ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to the dilepton invariant mass spectrum and to the forward-backward asymmetry in $B\to X_se^+e^-$ amount to several percent at most for $q^2/m^2_b < 0.3$ and $q^2/m^2_b > 0.6$. The ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ correction to the $B\to X_s\gamma$ decay rate is also computed and found to be +3%, which agrees in magnitude with previous calculations. Finally, we comment on long-distance effects in $B\to X_s\nu\bar\nu$, which in this case are extremely suppressed due to the absence of virtual photon contributions. |
hep-ph/9504353 | Zhen Cao | Zhen Cao and Rudolph C. Hwa | In Search for Signs of Chaos in Branching Processes | 10 pages, include 3 figures, compressed postscript file | Phys.Rev.Lett. 75 (1995) 1268-1271; Erratum-ibid. 75 (1995) 3588 | 10.1103/PhysRevLett.75.1268 | OITS-569 | hep-ph nucl-th | null | For systems that involve particle production through branching processes the
concept of chaos is explored. The measures that can describe their behaviors
are investigated. Monte Carlo simulation is used to generate events according
to perturbative QCD and an Abelian model. It is shown how the measures proposed
distinguish the two cases in ways that characterize the chaotic behavior.
| [
{
"created": "Fri, 21 Apr 1995 01:09:04 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Cao",
"Zhen",
""
],
[
"Hwa",
"Rudolph C.",
""
]
] | For systems that involve particle production through branching processes the concept of chaos is explored. The measures that can describe their behaviors are investigated. Monte Carlo simulation is used to generate events according to perturbative QCD and an Abelian model. It is shown how the measures proposed distinguish the two cases in ways that characterize the chaotic behavior. |
1705.05659 | Damir Becirevic | Damir Be\v{c}irevi\'c, Alain Le Yaouanc and Luis Oliver | $B$ decays to radially excited $D$ mesons in Heavy Quark Effective
Theory | 13 pages | Phys. Rev. D 96, 056016 (2017) | 10.1103/PhysRevD.96.056016 | LPT-Orsay-17-21 | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Semileptonic transitions $\overline{B} \to D^{(n)} \ell \overline{\nu}$,
where $D^{(n)} (n \not = 0)$ is a radially excited meson, have recently
attracted much attention as a way to understand some puzzles between theory and
data. Following closely the formalism of Falk and Neubert for the elastic case,
we study the $1/m_Q$ corrections to the heavy quark limit, in which the
inelastic Isgur-Wise function vanishes at zero recoil, $\xi^{(n)}(1) = 0\ (n
\not = 0)$. We find simple formulas that involve the derivative
$\xi^{(n)'}(1)$, and we propose a number of ways of isolating this quantity in
practice. We formulate also a generalization to the inelastic case of Luke's
theorem. On the other hand, although some $1/m_Q$ HQET results are satisfied in
the Bakamjian-Thomas relativistic quark model, we emphasize the problems
concerning these corrections in this scheme.
| [
{
"created": "Tue, 16 May 2017 11:48:50 GMT",
"version": "v1"
}
] | 2017-09-27 | [
[
"Bečirević",
"Damir",
""
],
[
"Yaouanc",
"Alain Le",
""
],
[
"Oliver",
"Luis",
""
]
] | Semileptonic transitions $\overline{B} \to D^{(n)} \ell \overline{\nu}$, where $D^{(n)} (n \not = 0)$ is a radially excited meson, have recently attracted much attention as a way to understand some puzzles between theory and data. Following closely the formalism of Falk and Neubert for the elastic case, we study the $1/m_Q$ corrections to the heavy quark limit, in which the inelastic Isgur-Wise function vanishes at zero recoil, $\xi^{(n)}(1) = 0\ (n \not = 0)$. We find simple formulas that involve the derivative $\xi^{(n)'}(1)$, and we propose a number of ways of isolating this quantity in practice. We formulate also a generalization to the inelastic case of Luke's theorem. On the other hand, although some $1/m_Q$ HQET results are satisfied in the Bakamjian-Thomas relativistic quark model, we emphasize the problems concerning these corrections in this scheme. |
hep-ph/9602212 | null | Joe Sato | Possible Candidates for SUSY E$_6$ GUT with an Intermediate Scale | 13 pages, LaTeX | Prog.Theor.Phys. 96 (1996) 597-610 | 10.1143/PTP.96.597 | KUNS-1371 | hep-ph | null | We study the possibility of an intermediate scale existing in supersymmetric
E$_6$ grand unified theories. The intermediate scale is demanded to be around
$10^{12}$ GeV so that neutrinos can obtain masses suitable for explaining the
experimental data on the deficit of solar neutrinos with the
Mikheev-Smirnov-Wolfenstein solution and the existence of hot dark matter. We
require that at the intermediate scale, a certain symmetry breakdown to the
Standard Model symmetry. We show that only a few E$_6$ subgroups are likely to
be realized as the intermediate symmetry, though there are many candidates for
the intermediate symmetry in E$_6$ GUT.
| [
{
"created": "Fri, 2 Feb 1996 07:30:29 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Sato",
"Joe",
""
]
] | We study the possibility of an intermediate scale existing in supersymmetric E$_6$ grand unified theories. The intermediate scale is demanded to be around $10^{12}$ GeV so that neutrinos can obtain masses suitable for explaining the experimental data on the deficit of solar neutrinos with the Mikheev-Smirnov-Wolfenstein solution and the existence of hot dark matter. We require that at the intermediate scale, a certain symmetry breakdown to the Standard Model symmetry. We show that only a few E$_6$ subgroups are likely to be realized as the intermediate symmetry, though there are many candidates for the intermediate symmetry in E$_6$ GUT. |
hep-ph/9207261 | null | P. Gondolo | Indirect detection of unstable heavy dark matter | 11pp, 1 figure available on request, PHYZZX, Uppsala U. PT17-1992 | Phys.Lett. B295 (1992) 104-108 | 10.1016/0370-2693(92)90097-N | null | hep-ph | null | Unstable relics with lifetime longer than the age of the Universe could be
the dark matter today. Electrons, photons and neutrinos are a natural outcome
of their decay and could be searched for in cosmic rays and in $\gamma$-ray and
neutrino detectors. I compare the sensitivities of these three types of
searches to the mass and lifetime of a generic unstable particle. I show that
if the relics constitute our galactic halo and their branching ratios into
electron-positrons, photons and neutrinos are comparable, neutrino searches
would probe the longest lifetimes for masses $\simge 40 \TeV$, while
electron-positron searches would be better but more uncertain for lighter
particles. If instead the relics are not clustered in our halo, neutrinos are
more sensitive a probe than $\gamma$-rays for masses $\simge 700 \GeV$. A $ 1
\sqkm $ neutrino telescope should be able to explore lifetimes up to $ \sim
10^{30} \sec $ while searching for neutrinos from unstable particles above the
atmospheric background.
| [
{
"created": "Mon, 27 Jul 1992 16:40:00 GMT",
"version": "v1"
}
] | 2009-10-22 | [
[
"Gondolo",
"P.",
""
]
] | Unstable relics with lifetime longer than the age of the Universe could be the dark matter today. Electrons, photons and neutrinos are a natural outcome of their decay and could be searched for in cosmic rays and in $\gamma$-ray and neutrino detectors. I compare the sensitivities of these three types of searches to the mass and lifetime of a generic unstable particle. I show that if the relics constitute our galactic halo and their branching ratios into electron-positrons, photons and neutrinos are comparable, neutrino searches would probe the longest lifetimes for masses $\simge 40 \TeV$, while electron-positron searches would be better but more uncertain for lighter particles. If instead the relics are not clustered in our halo, neutrinos are more sensitive a probe than $\gamma$-rays for masses $\simge 700 \GeV$. A $ 1 \sqkm $ neutrino telescope should be able to explore lifetimes up to $ \sim 10^{30} \sec $ while searching for neutrinos from unstable particles above the atmospheric background. |
hep-ph/0605090 | V. Parameswaran Nair | Jian Dai and V.P. Nair | Color Skyrmions in the Quark-Gluon Plasma | LaTeX, 13 pages, references added | Phys.Rev. D74 (2006) 085014 | 10.1103/PhysRevD.74.085014 | CCNY-HEP-06/7 | hep-ph hep-th nucl-th | null | We consider the general formulation of nonabelian fluid dynamics based on
symmetry considerations. We point out that, quite generally, this admits
solitonic excitations which are the color analog of skyrmions. Some general
properties of the solitons are discussed.
| [
{
"created": "Mon, 8 May 2006 20:48:39 GMT",
"version": "v1"
},
{
"created": "Sat, 20 May 2006 15:53:47 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Dai",
"Jian",
""
],
[
"Nair",
"V. P.",
""
]
] | We consider the general formulation of nonabelian fluid dynamics based on symmetry considerations. We point out that, quite generally, this admits solitonic excitations which are the color analog of skyrmions. Some general properties of the solitons are discussed. |
2007.13248 | Francisco J. de Anda | Alfredo Aranda, Francisco J. de Anda | Complete $E_8$ Unification in 10 Dimensions | 11 pages. v2: matches published version | Int.J.Mod.Phys.A 36 (2021) 15, 2150112 | 10.1142/S0217751X21501128 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A grand unification model with a single $E_8$ gauge superfield in 10
dimensions is presented. It is shown that, through the orbifold
$T^6/(\mathbb{Z}_6\times \mathbb{Z}_2)$ and its corresponding Wilson lines, the
symmetry is broken to the Standard Model one. Furthermore it is shown that the
model is anomaly free at all levels without the need to add any extra field
content. Thus a complete unification of the Standard Model into a single gauge
superfield is achieved consistently.
| [
{
"created": "Mon, 27 Jul 2020 00:05:43 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Jun 2021 20:47:54 GMT",
"version": "v2"
}
] | 2021-06-14 | [
[
"Aranda",
"Alfredo",
""
],
[
"de Anda",
"Francisco J.",
""
]
] | A grand unification model with a single $E_8$ gauge superfield in 10 dimensions is presented. It is shown that, through the orbifold $T^6/(\mathbb{Z}_6\times \mathbb{Z}_2)$ and its corresponding Wilson lines, the symmetry is broken to the Standard Model one. Furthermore it is shown that the model is anomaly free at all levels without the need to add any extra field content. Thus a complete unification of the Standard Model into a single gauge superfield is achieved consistently. |
2407.05807 | Sho Sugama | Ryuichiro Kitano, Joe Sato, Sho Sugama | T violation at a future neutrino factory | 22 pages, 9 figures | null | null | KEK-TH-2638 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the possibility of measuring T (time reversal) violation in a future
long baseline neutrino oscillation experiment. By assuming a neutrino factory
as a staging scenario of a muon collider at the J-PARC site, we find that the
${\nu}_e \to {\nu}_{\mu}$ oscillation probabilities can be measured with a good
accuracy at the Hyper-Kamiokande detector. By comparing with the probability of
the time-reversal process, ${\nu}_{\mu} \to {\nu}_e$, measured at the T2K/T2HK
experiments, one can determine the CP phase $\delta$ in the neutrino mixing
matrix if $| \sin(\delta)|$ is large enough. The determination of $\delta$ can
be made with poor knowledge of the matter density of the earth as T violation
is almost insensitive to the matter effects. The comparison of CP and
T-violation measurements, ${\it \`a\ la}$ the CPT theorem, provides us with a
non-trivial check of the three neutrino paradigm based on the quantum field
theory.
| [
{
"created": "Mon, 8 Jul 2024 10:36:07 GMT",
"version": "v1"
}
] | 2024-07-10 | [
[
"Kitano",
"Ryuichiro",
""
],
[
"Sato",
"Joe",
""
],
[
"Sugama",
"Sho",
""
]
] | We study the possibility of measuring T (time reversal) violation in a future long baseline neutrino oscillation experiment. By assuming a neutrino factory as a staging scenario of a muon collider at the J-PARC site, we find that the ${\nu}_e \to {\nu}_{\mu}$ oscillation probabilities can be measured with a good accuracy at the Hyper-Kamiokande detector. By comparing with the probability of the time-reversal process, ${\nu}_{\mu} \to {\nu}_e$, measured at the T2K/T2HK experiments, one can determine the CP phase $\delta$ in the neutrino mixing matrix if $| \sin(\delta)|$ is large enough. The determination of $\delta$ can be made with poor knowledge of the matter density of the earth as T violation is almost insensitive to the matter effects. The comparison of CP and T-violation measurements, ${\it \`a\ la}$ the CPT theorem, provides us with a non-trivial check of the three neutrino paradigm based on the quantum field theory. |
hep-ph/0307278 | Masakiyo Kitazawa | Masakiyo Kitazawa, Tomoi Koide, Teiji Kunihiro and Yukio Nemoto | Chiral and Color-superconducting Phase Transitions with Vector
Interaction in a Simple Model (Addenda) | null | Prog.Theor.Phys. 108 (2002) 929-951 | 10.1143/PTP.108.929 | null | hep-ph | null | In the preceding paper(Prog.Theor.Phys.108(2002)929 or hep-ph/0207255), we
have shown that the critical line of the first order chiral transition of QCD
can have two endpoints. In this addendum, we elucidate the mechanism to realize
the two-endpoint structure in the QCD phase diagram and argue the robustness
for the appearance of such an interesting phase structure.
| [
{
"created": "Tue, 22 Jul 2003 14:10:01 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Kitazawa",
"Masakiyo",
""
],
[
"Koide",
"Tomoi",
""
],
[
"Kunihiro",
"Teiji",
""
],
[
"Nemoto",
"Yukio",
""
]
] | In the preceding paper(Prog.Theor.Phys.108(2002)929 or hep-ph/0207255), we have shown that the critical line of the first order chiral transition of QCD can have two endpoints. In this addendum, we elucidate the mechanism to realize the two-endpoint structure in the QCD phase diagram and argue the robustness for the appearance of such an interesting phase structure. |
1907.11808 | Hongxi Xing | Peng Ru, Zhong-Bo Kang, Enke Wang, Hongxi Xing, Ben-Wei Zhang | A global extraction of the jet transport coefficient in cold nuclear
matter | 6 pages, 4 figures | Phys. Rev. D 103, 031901 (2021) | 10.1103/PhysRevD.103.L031901 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Within the framework of the generalized QCD factorization formalism, we
perform the first global analysis of the jet transport coefficient ($\hat q$)
for cold nuclear matter. The analysis takes into account the world data on
transverse momentum broadening in semi-inclusive electron-nucleus deep
inelastic scattering, Drell-Yan dilepton and heavy quarkonium production in
proton-nucleus collisions, as well as the nuclear modification of the structure
functions in deep inelastic scattering, comprising a total of 215 data points
from 8 data sets. For the first time, we clarify quantitatively the
universality and probing scale dependence of the nuclear medium property as
encoded in $\hat q$. We expect that the determined parametrization of $\hat q$
in cold nuclear matter will have significant impact on precise identification
of the transport property of hot dense medium created in heavy ion collisions.
| [
{
"created": "Fri, 26 Jul 2019 22:44:45 GMT",
"version": "v1"
}
] | 2021-03-03 | [
[
"Ru",
"Peng",
""
],
[
"Kang",
"Zhong-Bo",
""
],
[
"Wang",
"Enke",
""
],
[
"Xing",
"Hongxi",
""
],
[
"Zhang",
"Ben-Wei",
""
]
] | Within the framework of the generalized QCD factorization formalism, we perform the first global analysis of the jet transport coefficient ($\hat q$) for cold nuclear matter. The analysis takes into account the world data on transverse momentum broadening in semi-inclusive electron-nucleus deep inelastic scattering, Drell-Yan dilepton and heavy quarkonium production in proton-nucleus collisions, as well as the nuclear modification of the structure functions in deep inelastic scattering, comprising a total of 215 data points from 8 data sets. For the first time, we clarify quantitatively the universality and probing scale dependence of the nuclear medium property as encoded in $\hat q$. We expect that the determined parametrization of $\hat q$ in cold nuclear matter will have significant impact on precise identification of the transport property of hot dense medium created in heavy ion collisions. |
1008.1997 | Jessie Shelton | Jessie Shelton, Kathryn M. Zurek | Darkogenesis | 20 pages, 2 figures | Phys.Rev.D82:123512,2010 | 10.1103/PhysRevD.82.123512 | MCTP-10-28 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In standard models of baryogenesis and of dark matter, the mechanisms which
generate the densities in both sectors are unrelated to each other. In this
paper we explore models which generate the baryon asymmetry through the dark
matter sector, simultaneously relating the baryon asymmetry to the dark matter
density. In the class of models we explore, a dark matter asymmetry is
generated in the hidden sector through a first order phase transition. Within
the hidden sector, it is easy to achieve a sufficiently strong first order
phase transition and large enough $CP $ violation to generate the observed
asymmetry. This can happen above or below the electroweak phase transition, but
in both cases significantly before the dark matter becomes non-relativistic. We
study examples where the Asymmetric Dark Matter density is then transferred to
the baryons both through perturbative and non-perturbative communication
mechanisms, and show that in both cases cosmological constraints are satisfied
while a sufficient baryon asymmetry can be generated.
| [
{
"created": "Wed, 11 Aug 2010 20:16:23 GMT",
"version": "v1"
}
] | 2010-12-24 | [
[
"Shelton",
"Jessie",
""
],
[
"Zurek",
"Kathryn M.",
""
]
] | In standard models of baryogenesis and of dark matter, the mechanisms which generate the densities in both sectors are unrelated to each other. In this paper we explore models which generate the baryon asymmetry through the dark matter sector, simultaneously relating the baryon asymmetry to the dark matter density. In the class of models we explore, a dark matter asymmetry is generated in the hidden sector through a first order phase transition. Within the hidden sector, it is easy to achieve a sufficiently strong first order phase transition and large enough $CP $ violation to generate the observed asymmetry. This can happen above or below the electroweak phase transition, but in both cases significantly before the dark matter becomes non-relativistic. We study examples where the Asymmetric Dark Matter density is then transferred to the baryons both through perturbative and non-perturbative communication mechanisms, and show that in both cases cosmological constraints are satisfied while a sufficient baryon asymmetry can be generated. |
1110.2161 | Prerit Jaiswal | S.Dawson, C.B.Jackson, P. Jaiswal | SQCD Corrections to bg -> bh | Submitted to the Proceedings of the DPF-2011 Conference, Providence,
RI, August 8-13, 2011 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the Minimal Supersymmetric Standard Model, the effective b quark Yukawa
coupling to the lightest neutral Higgs boson is enhanced. Therefore, the
associated production of the lightest Higgs boson with a b quark is an
important discovery channel. We consider the SUSY QCD contributions from
squarks and gluinos and discuss the decoupling properties of these effects. A
comparision of our exact Order(alpha_s) results with those of a widely used
effective Lagrangian approach, the Delta_b approximation, is also presented.
| [
{
"created": "Mon, 10 Oct 2011 19:54:12 GMT",
"version": "v1"
}
] | 2011-10-11 | [
[
"Dawson",
"S.",
""
],
[
"Jackson",
"C. B.",
""
],
[
"Jaiswal",
"P.",
""
]
] | In the Minimal Supersymmetric Standard Model, the effective b quark Yukawa coupling to the lightest neutral Higgs boson is enhanced. Therefore, the associated production of the lightest Higgs boson with a b quark is an important discovery channel. We consider the SUSY QCD contributions from squarks and gluinos and discuss the decoupling properties of these effects. A comparision of our exact Order(alpha_s) results with those of a widely used effective Lagrangian approach, the Delta_b approximation, is also presented. |
hep-ph/9508218 | Genevieve Belanger | G. B\'elanger (ENSLAPP) | Symmetry breaking and electroweak physics at Photon Linear Colliders | LATEX, 12 pages, 3 fig, macros included, no changes in paper | null | null | ENSLAPP-A-527/95 | hep-ph | null | The physics potential of a high-energy photon collider is reviewed. The
emphasis is put on aspects related to the symmetry breaking sector, including
Higgs searches and production of longitudinal vector bosons.
| [
{
"created": "Wed, 2 Aug 1995 14:40:23 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Aug 1995 08:28:26 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Bélanger",
"G.",
"",
"ENSLAPP"
]
] | The physics potential of a high-energy photon collider is reviewed. The emphasis is put on aspects related to the symmetry breaking sector, including Higgs searches and production of longitudinal vector bosons. |
hep-ph/0105187 | R. N. Rogalyov | R.N. Rogalyov | A Possibility to Measure CP-Violating Effects in the Decay K --> mu nu
gamma | 12 pages, 4 figures; the overall sign changed, typos corrected | Phys.Lett.B521:243-251,2001 | 10.1016/S0370-2693(01)01198-4 | null | hep-ph | null | It is argued that a precise measurement of the transverse component of the
muon spin in the decay K --> mu nu gamma makes it possible to obtain more
stringent limits on CP-violating parameters of the leptoquark, SUSY and
left-right symmetric models. The results of the calculations of the CP-even
transverse component of the muon spin in the decay K --> mu nu gamma due to the
final-state electromagnetic interactions are presented. The weighted average of
the transverse component of the muon spin comprises 2.3 times 10^{-4}.
| [
{
"created": "Fri, 18 May 2001 16:50:15 GMT",
"version": "v1"
},
{
"created": "Sat, 19 May 2001 04:56:26 GMT",
"version": "v2"
},
{
"created": "Thu, 31 May 2001 17:41:56 GMT",
"version": "v3"
},
{
"created": "Fri, 1 Jun 2001 20:34:34 GMT",
"version": "v4"
},
{
"created": "Sun, 3 Jun 2001 10:34:26 GMT",
"version": "v5"
},
{
"created": "Thu, 5 Jul 2001 07:55:08 GMT",
"version": "v6"
},
{
"created": "Mon, 26 Aug 2002 08:54:31 GMT",
"version": "v7"
}
] | 2014-11-17 | [
[
"Rogalyov",
"R. N.",
""
]
] | It is argued that a precise measurement of the transverse component of the muon spin in the decay K --> mu nu gamma makes it possible to obtain more stringent limits on CP-violating parameters of the leptoquark, SUSY and left-right symmetric models. The results of the calculations of the CP-even transverse component of the muon spin in the decay K --> mu nu gamma due to the final-state electromagnetic interactions are presented. The weighted average of the transverse component of the muon spin comprises 2.3 times 10^{-4}. |
hep-ph/9908270 | Sergei Chekanov | I. V. Akushevich (NCPHEP), S. V. Chekanov (ANL) | Current-Target Correlations as a Probe of Delta_G/G in Polarized Deep
Inelastic Scattering | 8 pages, 3 eps figures, submitted to Phys. Lett. B | Phys.Lett.B462:329-334,1999 | 10.1016/S0370-2693(99)00933-8 | ANL-HEP-PR-99-89 | hep-ph | null | The measurement of the polarized gluon distribution function Delta_G/G using
current-target correlations in the Breit frame of deep inelastic scattering is
proposed. The approach is illustrated using a Monte Carlo simulation of
polarized $ep$-collisions for HERA energies.
| [
{
"created": "Thu, 5 Aug 1999 12:53:36 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Akushevich",
"I. V.",
"",
"NCPHEP"
],
[
"Chekanov",
"S. V.",
"",
"ANL"
]
] | The measurement of the polarized gluon distribution function Delta_G/G using current-target correlations in the Breit frame of deep inelastic scattering is proposed. The approach is illustrated using a Monte Carlo simulation of polarized $ep$-collisions for HERA energies. |
2408.05732 | Stephan Narison | S. Narison (LUPM, CNRS/Univ. Montpellier-FR and iHEPMAD, Univ.
Antananarivo (MG)) | QCD condensates and $\alpha_s$ from $\tau$-decay | Latex file 18 pages, 3 Tables, 14 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We improve the determinations of the QCD condensates within the SVZ expansion
in the axial-vector (A) channel using the ratio of Laplace sum rule (LSR)
${\cal R}_{10}^A(\tau)$ within stability criteria and $\tau$-like higher
moments ${R}_{n,A}$ within stability for arbitrary $\tau$-mass squared $s_0$.
We find the same violation of the factorization by a factor 6 of the four-quark
condensate as from $e^+e^- \to$ Hadrons data. One can notice a systematic
alternate sign and no exponential growth of the size of these condensates.
Then, we extract $\alpha_s$ from the lowest $\tau$-decay like moment and find:
$\alpha_s(M_\tau)\vert_{V+A}=0.3135(83)$ (FO) and 0.3322 (81) (CI) leading to:
$\alpha_s(M_Z)\vert_{V+A}=0.1177(10)_{fit}(3)_{evol.}$ (FO) and
$0.1200(9)_{fit}(3)_{evol.}$\,(CI). We extend the analysis to the V+A channel
and find: $ \alpha_s(M_\tau)\vert_{V+A}=0.3135(83)$ (FO) and 0.3322 (81) (CI)
leading to: $\alpha_s(M_Z)\vert_{V+A}=0.1177(10)_{fit}(3)_{evol.}$ (FO) and
$0.1200(9)_{fit}(3)_{evol.}$\,(CI). We observe that in different channels
($e^+e^-\to$ Hadrons, \, A,\,V+A), the extraction of $\alpha_s(M_\tau)$ at the
observed $\tau$-mass leads to an overestimate of its value. Our determinations
from these different channels lead to the mean: $ \alpha_s(M_\tau)=0.3140(44)$
(FO) and 0.3346 (35) (CI) leading to:
$\alpha_s(M_Z)=0.1178(6)_{fit}(3)_{evol.}$ (FO) and
$0.1202(4)_{fit}(3)_{evol.}$(CI). Comparisons with some other results are done.
| [
{
"created": "Sun, 11 Aug 2024 09:18:14 GMT",
"version": "v1"
}
] | 2024-08-13 | [
[
"Narison",
"S.",
"",
"LUPM, CNRS/Univ. Montpellier-FR and iHEPMAD, Univ.\n Antananarivo"
]
] | We improve the determinations of the QCD condensates within the SVZ expansion in the axial-vector (A) channel using the ratio of Laplace sum rule (LSR) ${\cal R}_{10}^A(\tau)$ within stability criteria and $\tau$-like higher moments ${R}_{n,A}$ within stability for arbitrary $\tau$-mass squared $s_0$. We find the same violation of the factorization by a factor 6 of the four-quark condensate as from $e^+e^- \to$ Hadrons data. One can notice a systematic alternate sign and no exponential growth of the size of these condensates. Then, we extract $\alpha_s$ from the lowest $\tau$-decay like moment and find: $\alpha_s(M_\tau)\vert_{V+A}=0.3135(83)$ (FO) and 0.3322 (81) (CI) leading to: $\alpha_s(M_Z)\vert_{V+A}=0.1177(10)_{fit}(3)_{evol.}$ (FO) and $0.1200(9)_{fit}(3)_{evol.}$\,(CI). We extend the analysis to the V+A channel and find: $ \alpha_s(M_\tau)\vert_{V+A}=0.3135(83)$ (FO) and 0.3322 (81) (CI) leading to: $\alpha_s(M_Z)\vert_{V+A}=0.1177(10)_{fit}(3)_{evol.}$ (FO) and $0.1200(9)_{fit}(3)_{evol.}$\,(CI). We observe that in different channels ($e^+e^-\to$ Hadrons, \, A,\,V+A), the extraction of $\alpha_s(M_\tau)$ at the observed $\tau$-mass leads to an overestimate of its value. Our determinations from these different channels lead to the mean: $ \alpha_s(M_\tau)=0.3140(44)$ (FO) and 0.3346 (35) (CI) leading to: $\alpha_s(M_Z)=0.1178(6)_{fit}(3)_{evol.}$ (FO) and $0.1202(4)_{fit}(3)_{evol.}$(CI). Comparisons with some other results are done. |
hep-ph/9910460 | Dieter Mueller | A.V. Belitsky, D. M\"uller, L. Niedermeier, A. Sch\"afer | Radiative corrections to deeply virtual Compton scattering | 9 pages LaTeX, 3 figures, czjphyse.cls required Talk given by D.
M\"uller at Inter. Workshop ``PRAHA-Spin99'', Prague, Sept. 6-11, 1999 | Czech.J.Phys. 50S1 (2000) 123-130 | 10.1007/s10582-000-0015-z | null | hep-ph | null | We discuss possibilities of measurement of deeply virtual Compton scattering
amplitudes via different asymmetries in order to access the underlying skewed
parton distributions. Perturbative one-loop coefficient functions and two-loop
evolution kernels, calculated recently by a tentative use of residual conformal
symmetry of QCD, are used for a model dependent numerical estimation of
scattering amplitudes.
| [
{
"created": "Sat, 23 Oct 1999 19:52:23 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Belitsky",
"A. V.",
""
],
[
"Müller",
"D.",
""
],
[
"Niedermeier",
"L.",
""
],
[
"Schäfer",
"A.",
""
]
] | We discuss possibilities of measurement of deeply virtual Compton scattering amplitudes via different asymmetries in order to access the underlying skewed parton distributions. Perturbative one-loop coefficient functions and two-loop evolution kernels, calculated recently by a tentative use of residual conformal symmetry of QCD, are used for a model dependent numerical estimation of scattering amplitudes. |
2110.07638 | Arvind Bhaskar | Arvind Bhaskar, Diganta Das, Tanumoy Mandal, Subhadip Mitra, Cyrin
Neeraj | Precise LHC limits on the $\rm{U}_1$ leptoquark parameter space | 6 pages, 3 figures, 1 Table. Contribution to the Proceedings of the
EPS-HEP 2021 Conference, references updated | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A TeV scale leptoquark (LQ) is one of the promising explanations of the
recent anomalies in the semileptonic decays of $B$ mesons. Among the various
LQs, the vector $\rm{U}_1$ is capable of explaining the anomalies in both
$R_{D^{(*)}}$ and $R_{K^{(*)}}$ observables. We use the current LHC data to put
bounds on the parameter space of $\rm{U}_1$ relevant for the anomalies. Precise
bounds are drawn by recasting the latest $\tau\tau$ and $\mu\mu$ searches by
the ATLAS and CMS collaborations. We find that it is imperative to include the
resonant production modes for obtaining limits in the low mass regions. For
higher mass points, the non-resonant production modes play a dominant role.
| [
{
"created": "Thu, 14 Oct 2021 18:02:50 GMT",
"version": "v1"
},
{
"created": "Sat, 29 Jan 2022 11:12:14 GMT",
"version": "v2"
}
] | 2022-02-01 | [
[
"Bhaskar",
"Arvind",
""
],
[
"Das",
"Diganta",
""
],
[
"Mandal",
"Tanumoy",
""
],
[
"Mitra",
"Subhadip",
""
],
[
"Neeraj",
"Cyrin",
""
]
] | A TeV scale leptoquark (LQ) is one of the promising explanations of the recent anomalies in the semileptonic decays of $B$ mesons. Among the various LQs, the vector $\rm{U}_1$ is capable of explaining the anomalies in both $R_{D^{(*)}}$ and $R_{K^{(*)}}$ observables. We use the current LHC data to put bounds on the parameter space of $\rm{U}_1$ relevant for the anomalies. Precise bounds are drawn by recasting the latest $\tau\tau$ and $\mu\mu$ searches by the ATLAS and CMS collaborations. We find that it is imperative to include the resonant production modes for obtaining limits in the low mass regions. For higher mass points, the non-resonant production modes play a dominant role. |
hep-ph/0210292 | Ingunn Kathrine Wehus | Ingunn Kathrine Wehus and Finn Ravndal | Dynamics of the scalar field in 5-dimensional Kaluza-Klein theory | 15 pages, some references added, version published | Int.J.Mod.Phys. A19 (2004) 4671-4686 | 10.1142/S0217751X04020609 | null | hep-ph astro-ph gr-qc | null | Using the language of differential forms, the Kaluza-Klein theory in 4+1
dimensions is derived. This theory unifies electromagnetic and gravitational
interactions in four dimensions when the extra space dimension is compactified.
Without any ad-hoc assumptions about the five-dimensional metric, the theory
also contains a scalar field coupled to the other fields. By a conformal
transformation the theory is transformed from the Jordan frame to the Einstein
frame where the physical content is more manifest. Including a cosmological
constant in the five-dimensional formulation, it is seen to result in an
exponential potential for the scalar field in four dimensions. A similar
potential is also found from the Casimir energy in the compact dimension. The
resulting scalar field dynamics mimics realistic models recently proposed for
cosmological quintessence.
| [
{
"created": "Tue, 22 Oct 2002 10:46:33 GMT",
"version": "v1"
},
{
"created": "Wed, 23 Oct 2002 10:52:50 GMT",
"version": "v2"
},
{
"created": "Mon, 29 Nov 2004 23:03:20 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Wehus",
"Ingunn Kathrine",
""
],
[
"Ravndal",
"Finn",
""
]
] | Using the language of differential forms, the Kaluza-Klein theory in 4+1 dimensions is derived. This theory unifies electromagnetic and gravitational interactions in four dimensions when the extra space dimension is compactified. Without any ad-hoc assumptions about the five-dimensional metric, the theory also contains a scalar field coupled to the other fields. By a conformal transformation the theory is transformed from the Jordan frame to the Einstein frame where the physical content is more manifest. Including a cosmological constant in the five-dimensional formulation, it is seen to result in an exponential potential for the scalar field in four dimensions. A similar potential is also found from the Casimir energy in the compact dimension. The resulting scalar field dynamics mimics realistic models recently proposed for cosmological quintessence. |
hep-ph/0411405 | Edmond Iancu | E. Iancu, D. N. Triantafyllopoulos | A Langevin equation for high energy evolution with pomeron loops | 56 pages, 10 figures | Nucl.Phys.A756:419-467,2005 | 10.1016/j.nuclphysa.2005.03.124 | SACLAY-T04/147 | hep-ph | null | We show that the Balitsky-JIMWLK equations proposed to describe non-linear
evolution in QCD at high energy fail to include the effects of fluctuations in
the gluon number, and thus to correctly describe both the low density regime
and the approach towards saturation. On the other hand, these fluctuations are
correctly encoded (in the limit where the number of colors is large) in
Mueller's color dipole picture, which however neglects saturation. By combining
the dipole picture at low density with the JIMWLK evolution at high density, we
construct a generalization of the Balitsky hierarchy which includes the
particle number fluctuations, and thus the pomeron loops. After an additional
coarse-graining in impact parameter space, this hierarchy is shown to reduce to
a Langevin equation in the universality class of the stochastic
Fisher-Kolmogorov-Petrovsky-Piscounov (sFKPP) equation. This equation implies
that the non-linear effects in the evolution become important already in the
high momentum regime where the average density is small, which signals the
breakdown of the BFKL approximation.
| [
{
"created": "Tue, 30 Nov 2004 19:49:01 GMT",
"version": "v1"
}
] | 2011-01-25 | [
[
"Iancu",
"E.",
""
],
[
"Triantafyllopoulos",
"D. N.",
""
]
] | We show that the Balitsky-JIMWLK equations proposed to describe non-linear evolution in QCD at high energy fail to include the effects of fluctuations in the gluon number, and thus to correctly describe both the low density regime and the approach towards saturation. On the other hand, these fluctuations are correctly encoded (in the limit where the number of colors is large) in Mueller's color dipole picture, which however neglects saturation. By combining the dipole picture at low density with the JIMWLK evolution at high density, we construct a generalization of the Balitsky hierarchy which includes the particle number fluctuations, and thus the pomeron loops. After an additional coarse-graining in impact parameter space, this hierarchy is shown to reduce to a Langevin equation in the universality class of the stochastic Fisher-Kolmogorov-Petrovsky-Piscounov (sFKPP) equation. This equation implies that the non-linear effects in the evolution become important already in the high momentum regime where the average density is small, which signals the breakdown of the BFKL approximation. |
0904.1698 | Alexander Kamenshchik | A.O. Barvinsky, A.Yu. Kamenshchik, C. Kiefer, A.A. Starobinsky, C.
Steinwachs | Asymptotic freedom in inflationary cosmology with a non-minimally
coupled Higgs field | CMB bounds on the Higgs mass are quantitatively and qualitatively
changed due to the effect of Goldstone modes, omitted in the first version;
the discussion of gauge and parametrization dependence of the results is
added | JCAP 0912:003,2009 | 10.1088/1475-7516/2009/12/003 | RESCEU -9/09 | hep-ph astro-ph.CO gr-qc hep-th | http://creativecommons.org/licenses/by-nc-sa/3.0/ | We consider the renormalization group improvement in the theory of the
Standard Model Higgs boson playing the role of an inflaton with a strong
non-minimal coupling to gravity. It suggests the range of the Higgs mass $135.6
{\rm GeV} \lesssim M_H\lesssim 184.5 {\rm GeV}$ compatible with the current CMB
data (the lower WMAP bound on $n_s$), which is close to the widely accepted
range dictated by the electroweak vacuum stability and perturbation theory
bounds. We find the phenomenon of asymptotic freedom induced by this
non-minimal curvature coupling, which brings the theory to the weak coupling
domain everywhere except at the lower and upper boundary of this range. The
renormalization group running of the basic quantity ${\boldmath $A_I$}$ -- the
anomalous scaling in the non-minimally coupled Standard Model, which
analytically determines all characteristics of the CMB spectrum -- brings
${\boldmath $A_I$}$ to small negative values at the inflation scale. This
property is crucial for the above results and may also underlie the formation
of initial conditions for the inflationary dynamics in quantum cosmology.
| [
{
"created": "Fri, 10 Apr 2009 14:58:51 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Oct 2009 08:31:06 GMT",
"version": "v2"
}
] | 2009-12-08 | [
[
"Barvinsky",
"A. O.",
""
],
[
"Kamenshchik",
"A. Yu.",
""
],
[
"Kiefer",
"C.",
""
],
[
"Starobinsky",
"A. A.",
""
],
[
"Steinwachs",
"C.",
""
]
] | We consider the renormalization group improvement in the theory of the Standard Model Higgs boson playing the role of an inflaton with a strong non-minimal coupling to gravity. It suggests the range of the Higgs mass $135.6 {\rm GeV} \lesssim M_H\lesssim 184.5 {\rm GeV}$ compatible with the current CMB data (the lower WMAP bound on $n_s$), which is close to the widely accepted range dictated by the electroweak vacuum stability and perturbation theory bounds. We find the phenomenon of asymptotic freedom induced by this non-minimal curvature coupling, which brings the theory to the weak coupling domain everywhere except at the lower and upper boundary of this range. The renormalization group running of the basic quantity ${\boldmath $A_I$}$ -- the anomalous scaling in the non-minimally coupled Standard Model, which analytically determines all characteristics of the CMB spectrum -- brings ${\boldmath $A_I$}$ to small negative values at the inflation scale. This property is crucial for the above results and may also underlie the formation of initial conditions for the inflationary dynamics in quantum cosmology. |
hep-ph/0003219 | Heinrich Paes | H.V. Klapdor-Kleingrothaus, H. P\"as, A.Y. Smirnov | Neutrino mass spectrum and neutrinoless double beta decay | 47 pages, 35 figures | Phys.Rev. D63 (2001) 073005 | 10.1103/PhysRevD.63.073005 | null | hep-ph hep-ex nucl-ex nucl-th | null | The relations between the effective Majorana mass of the electron neutrino,
$m_{ee}$, responsible for neutrinoless double beta decay, and the neutrino
oscillation parameters are considered. We show that for any specific
oscillation pattern $m_{ee}$ can take any value (from zero to the existing
upper bound) for normal mass hierarchy and it can have a minimum for inverse
hierarchy. This means that oscillation experiments cannot fix in general
$m_{ee}$. Mass ranges for $m_{ee}$ can be predicted in terms of oscillation
parameters with additional assumptions about the level of degeneracy and the
type of hierarchy of the neutrino mass spectrum. These predictions for $m_{ee}$
are systematically studied in the specific schemes of neutrino mass and flavor
which explain the solar and atmospheric neutrino data. The contributions from
individual mass eigenstates in terms of oscillation parameters have been
quantified. We study the dependence of $m_{ee}$ on the non-oscillation
parameters: the overall scale of the neutrino mass and the relative mass
phases. We analyze how forthcoming oscillation experiments will improve the
predictions for $m_{ee}$. On the basis of these studies we evaluate the
discovery potential of future \znbb decay searches. The role \znbb decay
searches will play in the reconstruction of the neutrino mass spectrum is
clarified. The key scales of $m_{ee}$, which will lead to the discrimination
among various schemes are: $m_{ee} \sim 0.1$ eV and $m_{ee} \sim 0.005$ eV.
| [
{
"created": "Wed, 22 Mar 2000 13:27:08 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Mar 2000 13:06:34 GMT",
"version": "v2"
},
{
"created": "Wed, 29 Mar 2000 15:55:31 GMT",
"version": "v3"
},
{
"created": "Sun, 8 Oct 2000 22:49:47 GMT",
"version": "v4"
}
] | 2009-10-31 | [
[
"Klapdor-Kleingrothaus",
"H. V.",
""
],
[
"Päs",
"H.",
""
],
[
"Smirnov",
"A. Y.",
""
]
] | The relations between the effective Majorana mass of the electron neutrino, $m_{ee}$, responsible for neutrinoless double beta decay, and the neutrino oscillation parameters are considered. We show that for any specific oscillation pattern $m_{ee}$ can take any value (from zero to the existing upper bound) for normal mass hierarchy and it can have a minimum for inverse hierarchy. This means that oscillation experiments cannot fix in general $m_{ee}$. Mass ranges for $m_{ee}$ can be predicted in terms of oscillation parameters with additional assumptions about the level of degeneracy and the type of hierarchy of the neutrino mass spectrum. These predictions for $m_{ee}$ are systematically studied in the specific schemes of neutrino mass and flavor which explain the solar and atmospheric neutrino data. The contributions from individual mass eigenstates in terms of oscillation parameters have been quantified. We study the dependence of $m_{ee}$ on the non-oscillation parameters: the overall scale of the neutrino mass and the relative mass phases. We analyze how forthcoming oscillation experiments will improve the predictions for $m_{ee}$. On the basis of these studies we evaluate the discovery potential of future \znbb decay searches. The role \znbb decay searches will play in the reconstruction of the neutrino mass spectrum is clarified. The key scales of $m_{ee}$, which will lead to the discrimination among various schemes are: $m_{ee} \sim 0.1$ eV and $m_{ee} \sim 0.005$ eV. |
1305.7421 | Arturo De Pace | W.M. Alberico (1 and 2), A. Beraudo (3), A. De Pace (1), A. Molinari
(1 and 2), M. Monteno (1), M. Nardi (1), F. Prino (1), M. Sitta (4) ((1)
INFN, Sezione di Torino, (2) Dipartimento di Fisica Teorica, Universita' di
Torino, (3) CERN, Theory Unit, (4) Universita' del Piemonte Orientale and
Gruppo Collegato INFN, Alessandria) | Heavy flavours in AA collisions: production, transport and final spectra | 16 pages, 21 figures | null | 10.1140/epjc/s10052-013-2481-z | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A multi-step setup for heavy-flavour studies in high-energy nucleus-nucleus
(AA) collisions --- addressing within a comprehensive framework the initial
Q-Qbar production, the propagation in the hot medium until decoupling and the
final hadronization and decays --- is presented. The initial hard production of
Q-Qbar pairs is simulated using the POWHEG pQCD event generator, interfaced
with the PYTHIA parton shower. Outcomes of the calculations are compared to
experimental data in pp collisions and are used as a validated benchmark for
the study of medium effects. In the AA case, the propagation of the heavy
quarks in the medium is described in a framework provided by the relativistic
Langevin equation. For the latter, different choices of transport coefficients
are explored (either provided by a perturbative calculation or extracted from
lattice-QCD simulations) and the corresponding numerical results are compared
to experimental data from RHIC and the LHC. In particular, outcomes for the
nuclear modification factor R_AA and for the elliptic flow v_2 of D/B mesons,
heavy-flavour electrons and non-prompt J/\psi's are displayed.
| [
{
"created": "Fri, 31 May 2013 14:36:07 GMT",
"version": "v1"
}
] | 2015-06-16 | [
[
"Alberico",
"W. M.",
"",
"1 and 2"
],
[
"Beraudo",
"A.",
"",
"1 and 2"
],
[
"De Pace",
"A.",
"",
"1 and 2"
],
[
"Molinari",
"A.",
"",
"1 and 2"
],
[
"Monteno",
"M.",
""
],
[
"Nardi",
"M.",
""
],
[
"Prino",
"F.",
""
],
[
"Sitta",
"M.",
""
]
] | A multi-step setup for heavy-flavour studies in high-energy nucleus-nucleus (AA) collisions --- addressing within a comprehensive framework the initial Q-Qbar production, the propagation in the hot medium until decoupling and the final hadronization and decays --- is presented. The initial hard production of Q-Qbar pairs is simulated using the POWHEG pQCD event generator, interfaced with the PYTHIA parton shower. Outcomes of the calculations are compared to experimental data in pp collisions and are used as a validated benchmark for the study of medium effects. In the AA case, the propagation of the heavy quarks in the medium is described in a framework provided by the relativistic Langevin equation. For the latter, different choices of transport coefficients are explored (either provided by a perturbative calculation or extracted from lattice-QCD simulations) and the corresponding numerical results are compared to experimental data from RHIC and the LHC. In particular, outcomes for the nuclear modification factor R_AA and for the elliptic flow v_2 of D/B mesons, heavy-flavour electrons and non-prompt J/\psi's are displayed. |
hep-ph/9907561 | null | P. N. Pandita and P. Francis Paulraj (Shillong) | Infra-red stable fixed points of Yukawa couplings in non-minimal
supersymmetric standard model with R-parity violation | 12 pages, latex, no figures. To appear in Phys. Lett. B | Phys.Lett. B462 (1999) 294-301 | 10.1016/S0370-2693(99)00923-5 | null | hep-ph | null | We study the renormalization group evolution and the infra-red stable fixed
points of the Yukawa couplings of the non-minimal supersymmetric standard model
(NMSSM) with R-parity violation. Retaining only the R-parity violating
couplings of higher generations, we analytically study the solutions of the
renormalization group equations of all the couplings of the model. We find that
there are no simultaneous non-trivial infra-red fixed points for all the
couplings of the model, and that the infra-red fixed point structure of the
model is similar to the MSSM with R-parity violation. In particular, we show
that only the baryon number violating coupling $\lambda^{''}_{233}$, together
with top- and bottom-quark Yukawa couplings, approaches a non-trivial infra-red
stable fixed point. However, this fixed point solution predicts a top-quark
Yukawa coupling which is incompatible with the top quark mass for any value of
$\tan\beta$.
| [
{
"created": "Fri, 30 Jul 1999 10:05:27 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Pandita",
"P. N.",
"",
"Shillong"
],
[
"Paulraj",
"P. Francis",
"",
"Shillong"
]
] | We study the renormalization group evolution and the infra-red stable fixed points of the Yukawa couplings of the non-minimal supersymmetric standard model (NMSSM) with R-parity violation. Retaining only the R-parity violating couplings of higher generations, we analytically study the solutions of the renormalization group equations of all the couplings of the model. We find that there are no simultaneous non-trivial infra-red fixed points for all the couplings of the model, and that the infra-red fixed point structure of the model is similar to the MSSM with R-parity violation. In particular, we show that only the baryon number violating coupling $\lambda^{''}_{233}$, together with top- and bottom-quark Yukawa couplings, approaches a non-trivial infra-red stable fixed point. However, this fixed point solution predicts a top-quark Yukawa coupling which is incompatible with the top quark mass for any value of $\tan\beta$. |
1307.6908 | Sergei Chekanov V. | R. Calkins, S. Chekanov, J. Conway, J. Dolen, R. Erbacher, J. Pilot,
R. Poschl, S. Rappoccio, Z. Sullivan, B. Tweedie | Reconstructing top quarks at the upgraded LHC and at future accelerators | Summary of the Snowmass "Top algorithms and detectors" High Energy
Frontier Study Group. 44 pages, 26 pages | null | null | ANL-HEP-CP-13-31 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This report describes the studies performed for the Snowmass "Top algorithms
and detectors" High Energy Frontier Study Group.
| [
{
"created": "Fri, 26 Jul 2013 01:57:17 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Aug 2013 20:49:27 GMT",
"version": "v2"
},
{
"created": "Thu, 3 Oct 2013 18:23:00 GMT",
"version": "v3"
}
] | 2013-10-04 | [
[
"Calkins",
"R.",
""
],
[
"Chekanov",
"S.",
""
],
[
"Conway",
"J.",
""
],
[
"Dolen",
"J.",
""
],
[
"Erbacher",
"R.",
""
],
[
"Pilot",
"J.",
""
],
[
"Poschl",
"R.",
""
],
[
"Rappoccio",
"S.",
""
],
[
"Sullivan",
"Z.",
""
],
[
"Tweedie",
"B.",
""
]
] | This report describes the studies performed for the Snowmass "Top algorithms and detectors" High Energy Frontier Study Group. |
hep-ph/9708255 | Bernd Kniehl | K.G. Chetyrkin, B.A. Kniehl, M. Steinhauser (MPI Munich) | Decoupling Relations to O(alpha_s^3) and their Connection to Low-Energy
Theorems | 28 pages (Latex), 4 figures (Postscript), some references added | Nucl.Phys. B510 (1998) 61-87 | 10.1016/S0550-3213(97)00649-4 | MPI/PhT/97-41 | hep-ph | null | If quantum chromodynamics (QCD) is renormalized by minimal subtraction (MS),
at higher orders, the strong coupling constant alpha_s and the quark masses m_q
exhibit discontinuities at the flavour thresholds, which are controlled by
so-called decoupling constants, zeta_g and zeta_m, respectively. Adopting the
modified MS (MS-bar) scheme, we derive simple formulae which reduce the
calculation of zeta_g and zeta_m to the solution of vacuum integrals. This
allows us to evaluate zeta_g and zeta_m through three loops. We also establish
low-energy theorems, valid to all orders, which relate the effective couplings
of the Higgs boson to gluons and light quarks, due to the virtual presence of a
heavy quark h, to the logarithmic derivatives w.r.t. m_h of zeta_g and zeta_m,
respectively. Fully exploiting present knowledge of the anomalous dimensions of
alpha_s and m_q, we thus calculate these effective couplings through four
loops. Finally, we perform a similar analysis for the coupling of the Higgs
boson to photons.
| [
{
"created": "Tue, 5 Aug 1997 20:36:09 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Aug 1997 10:21:52 GMT",
"version": "v2"
}
] | 2009-10-30 | [
[
"Chetyrkin",
"K. G.",
"",
"MPI Munich"
],
[
"Kniehl",
"B. A.",
"",
"MPI Munich"
],
[
"Steinhauser",
"M.",
"",
"MPI Munich"
]
] | If quantum chromodynamics (QCD) is renormalized by minimal subtraction (MS), at higher orders, the strong coupling constant alpha_s and the quark masses m_q exhibit discontinuities at the flavour thresholds, which are controlled by so-called decoupling constants, zeta_g and zeta_m, respectively. Adopting the modified MS (MS-bar) scheme, we derive simple formulae which reduce the calculation of zeta_g and zeta_m to the solution of vacuum integrals. This allows us to evaluate zeta_g and zeta_m through three loops. We also establish low-energy theorems, valid to all orders, which relate the effective couplings of the Higgs boson to gluons and light quarks, due to the virtual presence of a heavy quark h, to the logarithmic derivatives w.r.t. m_h of zeta_g and zeta_m, respectively. Fully exploiting present knowledge of the anomalous dimensions of alpha_s and m_q, we thus calculate these effective couplings through four loops. Finally, we perform a similar analysis for the coupling of the Higgs boson to photons. |
2108.05786 | Sanghwa Park | Sanghwa Park, Alberto Accardi, Xiaoxian Jing, J.F. Owens | CJ15 global PDF analysis with new electroweak data from the STAR and
SeaQuest experiments | null | null | null | JLAB-THY-21-3465 | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We present updates to a recent CTEQ-Jefferson Lab (CJ) global analysis of
parton distribution functions with a new set of electroweak data that provide
unique access to quark flavor separation in the proton. In particular, recent
$W$ and $Z$ boson measurements from the STAR experiment at RHIC put additional
constraints on light quarks and antiquarks near the valence regime. The new
measurement of the Drell-Yan lepton pair production ratio in $p+p$ and $p+d$
collisions by the SeaQuest experiment at Fermilab extends the large-$x$
coverage of the previous E866 experiment and sheds new light on the light
antiquarks distribution. In this report, the impact of these new data sets on
parton distribution functions will be presented with emphasis given to the
flavor asymmetry of the light antiquark sea at large values of the parton
momentum $x$.
| [
{
"created": "Thu, 12 Aug 2021 14:56:47 GMT",
"version": "v1"
}
] | 2021-08-13 | [
[
"Park",
"Sanghwa",
""
],
[
"Accardi",
"Alberto",
""
],
[
"Jing",
"Xiaoxian",
""
],
[
"Owens",
"J. F.",
""
]
] | We present updates to a recent CTEQ-Jefferson Lab (CJ) global analysis of parton distribution functions with a new set of electroweak data that provide unique access to quark flavor separation in the proton. In particular, recent $W$ and $Z$ boson measurements from the STAR experiment at RHIC put additional constraints on light quarks and antiquarks near the valence regime. The new measurement of the Drell-Yan lepton pair production ratio in $p+p$ and $p+d$ collisions by the SeaQuest experiment at Fermilab extends the large-$x$ coverage of the previous E866 experiment and sheds new light on the light antiquarks distribution. In this report, the impact of these new data sets on parton distribution functions will be presented with emphasis given to the flavor asymmetry of the light antiquark sea at large values of the parton momentum $x$. |
hep-ph/9309328 | null | J. Milana | On the $A$ dependence of $R = \sigma_L/\sigma_T$ and the $Q^2$
dependence of Shadowing | 10 pages + 2 Figures, DOE/ER/40762--019, UMPP \#94--039 | Phys.Rev.C49:2820-2823,1994 | 10.1103/PhysRevC.49.2820 | null | hep-ph | null | A higher--twist nuclear enhancement of $R = \sigma_L/\sigma_T$, as might be
expected to arise due to fermi motion and whose magnitude is within the
error-bars of recent experiment, is shown to lead to a monotonic {\it decrease}
in the ratio of nuclear vs. nucleon cross--sections at small Bjorken $x$ for
{\it increasing} $Q^2$. This effect at small $x$, comparable in magnitude to
those reported for shadowing, is driven mainly by kinematic factors and
essentially vanishes for $x > .1$. Its unusual $Q^2$ dependence rather
complicates the unravelling from present data in the shadowing region the
corresponding dependence in $Q^2$ of the nuclear structure functions,
$F_2^{A}(x,Q^2)$.
| [
{
"created": "Mon, 27 Sep 1993 18:23:44 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Milana",
"J.",
""
]
] | A higher--twist nuclear enhancement of $R = \sigma_L/\sigma_T$, as might be expected to arise due to fermi motion and whose magnitude is within the error-bars of recent experiment, is shown to lead to a monotonic {\it decrease} in the ratio of nuclear vs. nucleon cross--sections at small Bjorken $x$ for {\it increasing} $Q^2$. This effect at small $x$, comparable in magnitude to those reported for shadowing, is driven mainly by kinematic factors and essentially vanishes for $x > .1$. Its unusual $Q^2$ dependence rather complicates the unravelling from present data in the shadowing region the corresponding dependence in $Q^2$ of the nuclear structure functions, $F_2^{A}(x,Q^2)$. |
hep-ph/9301269 | V. Belyaev | V.M.Belyaev | Soft Modes Contribution into Path Integral | 16 pages, 1 Figure, CEBAF-93-03.(Standard LATEX file) | Int.J.Mod.Phys.A8:4019-4030,1993 | 10.1142/S0217751X93001648 | null | hep-ph | null | A method for nonperturbative path integral calculation is proposed.
Quantum mechanics as a simplest example of a quantum field theory is
considered. All modes are decomposed into hard (with frequencies $\omega^2
>\omega^2_0$) and soft (with frequencies $\omega^2 <\omega^2_0$) ones,
$\omega_0$ is a some parameter. Hard modes contribution is considered by weak
coupling expansion. A low energy effective Lagrangian for soft modes is used.
In the case of soft modes we apply a strong coupling expansion. To realize this
expansion a special basis in functional space of trajectories is considered. A
good convergency of proposed procedure in the case of potential $V(x)=\lambda
x^4$ is demonstrated. Ground state energy of the unharmonic oscillator is
calculated.
| [
{
"created": "Tue, 26 Jan 1993 00:25:40 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Jan 1993 20:27:57 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Belyaev",
"V. M.",
""
]
] | A method for nonperturbative path integral calculation is proposed. Quantum mechanics as a simplest example of a quantum field theory is considered. All modes are decomposed into hard (with frequencies $\omega^2 >\omega^2_0$) and soft (with frequencies $\omega^2 <\omega^2_0$) ones, $\omega_0$ is a some parameter. Hard modes contribution is considered by weak coupling expansion. A low energy effective Lagrangian for soft modes is used. In the case of soft modes we apply a strong coupling expansion. To realize this expansion a special basis in functional space of trajectories is considered. A good convergency of proposed procedure in the case of potential $V(x)=\lambda x^4$ is demonstrated. Ground state energy of the unharmonic oscillator is calculated. |
2308.01657 | Amruta Mishra | Pallabi Parui and Amruta Mishra | Spectral properties of $\omega$, $\rho$ and $A_1$ mesons in hot
magnetized matter: effects of (inverse) magnetic catalysis | 40 pages, 14 figures, version to be published in Phys. Rev. D. arXiv
admin note: text overlap with arXiv:2209.02455 | null | null | null | hep-ph | http://creativecommons.org/publicdomain/zero/1.0/ | In-medium masses of the light vector $\omega$, $\rho$ and axial-vector $A_1$
mesons are studied in the magnetized hot nuclear matter, accounting for the
effects of (inverse) magnetic catalysis. The in-medium partial decay widths for
the $A_1\rightarrow \rho \pi$ channels are studied from the in-medium masses of
the initial and the final state particles, by applying a phenomenological
Lagrangian to account for the $A_1\rho\pi$ interaction vertices. The masses are
calculated within the QCD sum rule framework, with the medium effects coming
through the light quark ($\sim \langle \bar{q}q \rangle$) and the scalar gluon
condensates ($\sim \langle G^2 \rangle$), as well as the light four-quark
condensate ($\sim \langle \bar{q}q\rangle^2 $). The condensates are calculated
within the chiral $SU(3)$ model in terms of the medium modified scalar fields:
isoscalar $\sigma$, $\zeta$, isovector $\delta$ and the dilaton field $\chi$.
The effects of magnetic fields are incorporated through the magnetized Dirac
sea contribution as well as the Landau energy levels of protons. The
incorporation of the magnetic field through the Dirac sea of nucleons lead to
an enhancement (reduction) of the light quark condensates with magnetic field,
give rise to the phenomenon of magnetic (inverse) catalysis. The effects of
(inverse) magnetic catalysis at finite temperature nuclear matter are studied
on the spectral functions and production cross-sections of the neutral $\rho$
and $A_1$ mesons. This may affect the production of the light vector and
axial-vector mesons in the peripheral heavy-ion collision experiments, where
estimated magnetic field is very large at the early stages of collisions with
very high temperature.
| [
{
"created": "Thu, 3 Aug 2023 09:44:05 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Nov 2023 12:12:36 GMT",
"version": "v2"
}
] | 2023-12-01 | [
[
"Parui",
"Pallabi",
""
],
[
"Mishra",
"Amruta",
""
]
] | In-medium masses of the light vector $\omega$, $\rho$ and axial-vector $A_1$ mesons are studied in the magnetized hot nuclear matter, accounting for the effects of (inverse) magnetic catalysis. The in-medium partial decay widths for the $A_1\rightarrow \rho \pi$ channels are studied from the in-medium masses of the initial and the final state particles, by applying a phenomenological Lagrangian to account for the $A_1\rho\pi$ interaction vertices. The masses are calculated within the QCD sum rule framework, with the medium effects coming through the light quark ($\sim \langle \bar{q}q \rangle$) and the scalar gluon condensates ($\sim \langle G^2 \rangle$), as well as the light four-quark condensate ($\sim \langle \bar{q}q\rangle^2 $). The condensates are calculated within the chiral $SU(3)$ model in terms of the medium modified scalar fields: isoscalar $\sigma$, $\zeta$, isovector $\delta$ and the dilaton field $\chi$. The effects of magnetic fields are incorporated through the magnetized Dirac sea contribution as well as the Landau energy levels of protons. The incorporation of the magnetic field through the Dirac sea of nucleons lead to an enhancement (reduction) of the light quark condensates with magnetic field, give rise to the phenomenon of magnetic (inverse) catalysis. The effects of (inverse) magnetic catalysis at finite temperature nuclear matter are studied on the spectral functions and production cross-sections of the neutral $\rho$ and $A_1$ mesons. This may affect the production of the light vector and axial-vector mesons in the peripheral heavy-ion collision experiments, where estimated magnetic field is very large at the early stages of collisions with very high temperature. |
2402.09482 | Andr\'e Cordeiro | Carlota Andr\'es, Liliana Apolin\'ario, N\'estor Armesto, Andr\'e
Cordeiro, Fabio Dominguez, Jos\'e Guilherme Milhano | Parton cascades at DLA: the role of the evolution variable | 4 pages, 3 figures. Proceedings for a parallel presentation at Quark
Matter 2023 in Houston, Texas, United States of America from 3-9 September
2023. arXiv admin note: text overlap with arXiv:2307.08410 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The theoretical treatment of jet quenching lacks a full description of the
interplay between vacuum-like emissions, usually formulated in momentum space,
and medium induced ones that demand an interface with a space-time picture of
the expanding medium and thus must be formulated in position space. In this
work we build a toy Monte-Carlo parton shower ordered in formation time,
virtual mass, and opening angle, which are equivalent at leading logarithmic
accuracy. Aiming to explore a link with jet substructure, we compute the Lund
plane distributions for the different ordering prescriptions. Further, we
investigate the sensitivity of ordering prescriptions to medium effects by
counting the number of events eliminated by a decoherence condition.
| [
{
"created": "Tue, 13 Feb 2024 21:36:45 GMT",
"version": "v1"
}
] | 2024-02-16 | [
[
"Andrés",
"Carlota",
""
],
[
"Apolinário",
"Liliana",
""
],
[
"Armesto",
"Néstor",
""
],
[
"Cordeiro",
"André",
""
],
[
"Dominguez",
"Fabio",
""
],
[
"Milhano",
"José Guilherme",
""
]
] | The theoretical treatment of jet quenching lacks a full description of the interplay between vacuum-like emissions, usually formulated in momentum space, and medium induced ones that demand an interface with a space-time picture of the expanding medium and thus must be formulated in position space. In this work we build a toy Monte-Carlo parton shower ordered in formation time, virtual mass, and opening angle, which are equivalent at leading logarithmic accuracy. Aiming to explore a link with jet substructure, we compute the Lund plane distributions for the different ordering prescriptions. Further, we investigate the sensitivity of ordering prescriptions to medium effects by counting the number of events eliminated by a decoherence condition. |
2310.14314 | Hantian Zhang | Hantian Zhang | Progress in two-loop electroweak corrections to gg -> HH and gg -> gH | Contribution to the proceedings of the European Physical Society
Conference on High Energy Physics (EPS-HEP2023), 21-25 August 2023, Hamburg,
Germany | null | null | TTP23-048, P3H-23-074 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these proceedings, we summarise our recent calculations of next-to-leading
order electroweak corrections to Higgs boson pair and Higgs boson plus jet
production. The calculations are divided into different regions. In the
high-energy region, we analytically calculate the Higgs boson contribution to
the leading two-loop Yukawa corrections for $gg\to HH$. These corrections are
generated by a single virtual Higgs boson exchange within the top quark loop.
Our high-energy expansion yields precise predictions for the region where the
Higgs boson transverse momenta $p_T > 120 $ GeV. In the low-energy region, we
compute the complete two-loop electroweak corrections to $gg\to HH$ and $gg \to
gH$. We obtain analytic results through the large top quark mass expansion,
covering all sectors of the Standard Model.
| [
{
"created": "Sun, 22 Oct 2023 14:21:58 GMT",
"version": "v1"
}
] | 2023-10-24 | [
[
"Zhang",
"Hantian",
""
]
] | In these proceedings, we summarise our recent calculations of next-to-leading order electroweak corrections to Higgs boson pair and Higgs boson plus jet production. The calculations are divided into different regions. In the high-energy region, we analytically calculate the Higgs boson contribution to the leading two-loop Yukawa corrections for $gg\to HH$. These corrections are generated by a single virtual Higgs boson exchange within the top quark loop. Our high-energy expansion yields precise predictions for the region where the Higgs boson transverse momenta $p_T > 120 $ GeV. In the low-energy region, we compute the complete two-loop electroweak corrections to $gg\to HH$ and $gg \to gH$. We obtain analytic results through the large top quark mass expansion, covering all sectors of the Standard Model. |
2312.03340 | Yoshihiro Shigekami | Jia Liu, Yuichiro Nakai, Yoshihiro Shigekami, Muyuan Song | Probing CP Violation in Dark Sector through the Electron Electric Dipole
Moment | 46 pages, 8 figures, v2: some references and comments are added | null | 10.1007/JHEP02(2024)082 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | The Two Higgs Doublet Model (2HDM) stands as a promising framework for
exploring physics beyond the Standard Model (SM). Within this context, we
explore the possibility that the two Higgs doublets may serve as a window into
CP-violating dark sectors, neutral under the SM gauge groups. Specifically, our
focus is on investigating the electric dipole moment (EDM) of the electron,
generated solely by CP violation in the dark sector. We present a general
formula for the electron EDM, without specifying the structure of the dark
sectors, and discuss the current constraints on various dark sector models. It
is noteworthy that even in the case of a CP-conserving 2HDM, the resulting
electron EDM is capable of reaching the current experimental limit, with CP
violation arising exclusively from the dark sectors. Furthermore, we introduce
a heavy dark sector (HDS) approximation for the analytic calculation of the
EDM, assuming that the dark sector particles are much heavier than the physical
states in the 2HDM. This approximation yields simplified analytic results that
are consistent with the full numerical calculations.
| [
{
"created": "Wed, 6 Dec 2023 08:23:16 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Feb 2024 06:00:43 GMT",
"version": "v2"
}
] | 2024-02-16 | [
[
"Liu",
"Jia",
""
],
[
"Nakai",
"Yuichiro",
""
],
[
"Shigekami",
"Yoshihiro",
""
],
[
"Song",
"Muyuan",
""
]
] | The Two Higgs Doublet Model (2HDM) stands as a promising framework for exploring physics beyond the Standard Model (SM). Within this context, we explore the possibility that the two Higgs doublets may serve as a window into CP-violating dark sectors, neutral under the SM gauge groups. Specifically, our focus is on investigating the electric dipole moment (EDM) of the electron, generated solely by CP violation in the dark sector. We present a general formula for the electron EDM, without specifying the structure of the dark sectors, and discuss the current constraints on various dark sector models. It is noteworthy that even in the case of a CP-conserving 2HDM, the resulting electron EDM is capable of reaching the current experimental limit, with CP violation arising exclusively from the dark sectors. Furthermore, we introduce a heavy dark sector (HDS) approximation for the analytic calculation of the EDM, assuming that the dark sector particles are much heavier than the physical states in the 2HDM. This approximation yields simplified analytic results that are consistent with the full numerical calculations. |
hep-ph/0211255 | Namit Mahajan | Namit Mahajan (Univ. of Delhi) | $B \to X_s +$ missing energy in models with large extra dimensions | 12 page latex file including 4 eps figures. Details of calculation
and references added. Version to appear in PRD | null | 10.1103/PhysRevD.68.034012 | null | hep-ph | null | We study the neutral current flavour changing rare decay mode $B\to X_s +$
missing energy within the framework of theories with large extra spatial
dimensions. The corresponding Standard Model signature is $B\to X_s + \nu
\bar{\nu}$. But in theories with large extra dimensions, it is possible to have
scalars and gravitons in the final state making it quite distinct from any
other scenario where there are no gravitons and the scalars are far too heavier
than the B-meson to be present as external particles. We give an estimate of
the branching ratio for such processes for different values of the number of
extra dimensions and the effective scale of the effective theory.
| [
{
"created": "Sat, 16 Nov 2002 08:56:22 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Jul 2003 04:52:27 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Mahajan",
"Namit",
"",
"Univ. of Delhi"
]
] | We study the neutral current flavour changing rare decay mode $B\to X_s +$ missing energy within the framework of theories with large extra spatial dimensions. The corresponding Standard Model signature is $B\to X_s + \nu \bar{\nu}$. But in theories with large extra dimensions, it is possible to have scalars and gravitons in the final state making it quite distinct from any other scenario where there are no gravitons and the scalars are far too heavier than the B-meson to be present as external particles. We give an estimate of the branching ratio for such processes for different values of the number of extra dimensions and the effective scale of the effective theory. |
1908.08256 | Yu-Chen Chen | Yu-Chen Janice Chen, Cheng-Wei Chiang, Giovanna Cottin and David Shih | Boosted $W/Z$ Tagging with Jet Charge and Deep Learning | 31 pages, 36 figures. [version2] Updated to PRD version | Phys. Rev. D 101, 053001 (2020) | 10.1103/PhysRevD.101.053001 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We demonstrate that the classification of boosted, hadronically-decaying weak
gauge bosons can be significantly improved over traditional cut-based and
BDT-based methods using deep learning and the jet charge variable. We construct
binary taggers for $W^+$ vs. $W^-$ and $Z$ vs. $W$ discrimination, as well as
an overall ternary classifier for $W^+$/$W^-$/$Z$ discrimination. Besides a
simple convolutional neural network (CNN), we also explore a composite of two
CNNs, with different numbers of layers in the jet $p_{T}$ and jet charge
channels. We find that this novel structure boosts the performance particularly
when considering the $Z$ boson as signal. The methods presented here can
enhance the physics potential in SM measurements and searches for new physics
that are sensitive to the electric charge of weak gauge bosons.
| [
{
"created": "Thu, 22 Aug 2019 08:42:45 GMT",
"version": "v1"
},
{
"created": "Thu, 19 Mar 2020 14:36:50 GMT",
"version": "v2"
}
] | 2020-03-25 | [
[
"Chen",
"Yu-Chen Janice",
""
],
[
"Chiang",
"Cheng-Wei",
""
],
[
"Cottin",
"Giovanna",
""
],
[
"Shih",
"David",
""
]
] | We demonstrate that the classification of boosted, hadronically-decaying weak gauge bosons can be significantly improved over traditional cut-based and BDT-based methods using deep learning and the jet charge variable. We construct binary taggers for $W^+$ vs. $W^-$ and $Z$ vs. $W$ discrimination, as well as an overall ternary classifier for $W^+$/$W^-$/$Z$ discrimination. Besides a simple convolutional neural network (CNN), we also explore a composite of two CNNs, with different numbers of layers in the jet $p_{T}$ and jet charge channels. We find that this novel structure boosts the performance particularly when considering the $Z$ boson as signal. The methods presented here can enhance the physics potential in SM measurements and searches for new physics that are sensitive to the electric charge of weak gauge bosons. |
hep-ph/0401091 | Michal Malinsky | Michal Malinsky | Some aspects of radiative corrections and non-decoupling effects of
heavy Higgs bosons in two Higgs Doublet Model | 6 pages, 3 figures; to appear in the proceedings of the AM2003
conference | SpringerProc.Phys.98:473-476,2005 | 10.1007/3-540-26798-0_48 | null | hep-ph | null | The possibility of having relatively large non-decoupling effects of the
heavy Higgs particles within the two-Higgs doublet extension of the electroweak
standard model is briefly discussed and demonstrated on an example of the
one-loop amplitude of the process e^+e^- -> W^+W^-
| [
{
"created": "Tue, 13 Jan 2004 13:29:10 GMT",
"version": "v1"
}
] | 2015-06-25 | [
[
"Malinsky",
"Michal",
""
]
] | The possibility of having relatively large non-decoupling effects of the heavy Higgs particles within the two-Higgs doublet extension of the electroweak standard model is briefly discussed and demonstrated on an example of the one-loop amplitude of the process e^+e^- -> W^+W^- |
hep-ph/9801396 | Frank E. Paige | Frank E. Paige | Sleptons at a First Muon Collider | LaTeX with included aipproc.sty, 7 pages, 5 figures, to appear in
Workshop on Physics at the First Muon Collider | null | 10.1063/1.56219 | BNL-HET-98/6 | hep-ph | null | Signatures for sleptons, which have been extensively studied for the Next
Linear Collider, are reexamined taking into account some of the different
features of a First Muon Collider.
| [
{
"created": "Thu, 22 Jan 1998 21:07:53 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Paige",
"Frank E.",
""
]
] | Signatures for sleptons, which have been extensively studied for the Next Linear Collider, are reexamined taking into account some of the different features of a First Muon Collider. |
2109.02987 | Marius Wiesemann | Marco Battaglia, Massimiliano Grazzini, Michael Spira, Marius
Wiesemann | Sensitivity to BSM effects in the Higgs $p_T$ spectrum within SMEFT | 39 pages, 14 figures, 1 table | null | 10.1007/JHEP11(2021)173 | MPP-2021-135, PSI-PR-21-18, ZU-TH 37/21 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The study of Higgs boson production at large transverse momentum is one of
the new frontiers for the LHC Higgs physics programme. This paper considers
boosted Higgs production in the Standard Model Effective Field Theory (SMEFT).
We focus on the gluon fusion and $t{\bar t}H$ production processes and study
the effects of three dimension-6 operators: the top Yukawa operator, the
gluon-Higgs effective coupling and the chromomagnetic dipole operator of the
top quark. We perform a detailed study of the sensitivity of current and future
LHC data to the corresponding Wilson coefficients, consistently accounting for
their renormalisation group evolution. We compare the sensitivities obtained
with only linear and linear + quadratic terms in the SMEFT by using the
spectrum shape and the addition of the Higgs signal yields. We also consider
fits of $p_T$ spectra in models with heavy-top partners and in MSSM scenarios
with a light scalar top and study the validity of the SMEFT assumptions as a
function of the new-particle masses and the Higgs $p_T$ range. Finally, we
extract constraints on the Wilson coefficients for gluon fusion from a
simultaneous fit to the ATLAS and CMS data and compare our results with those
obtained in global SMEFT analyses.
| [
{
"created": "Tue, 7 Sep 2021 10:45:47 GMT",
"version": "v1"
}
] | 2021-12-08 | [
[
"Battaglia",
"Marco",
""
],
[
"Grazzini",
"Massimiliano",
""
],
[
"Spira",
"Michael",
""
],
[
"Wiesemann",
"Marius",
""
]
] | The study of Higgs boson production at large transverse momentum is one of the new frontiers for the LHC Higgs physics programme. This paper considers boosted Higgs production in the Standard Model Effective Field Theory (SMEFT). We focus on the gluon fusion and $t{\bar t}H$ production processes and study the effects of three dimension-6 operators: the top Yukawa operator, the gluon-Higgs effective coupling and the chromomagnetic dipole operator of the top quark. We perform a detailed study of the sensitivity of current and future LHC data to the corresponding Wilson coefficients, consistently accounting for their renormalisation group evolution. We compare the sensitivities obtained with only linear and linear + quadratic terms in the SMEFT by using the spectrum shape and the addition of the Higgs signal yields. We also consider fits of $p_T$ spectra in models with heavy-top partners and in MSSM scenarios with a light scalar top and study the validity of the SMEFT assumptions as a function of the new-particle masses and the Higgs $p_T$ range. Finally, we extract constraints on the Wilson coefficients for gluon fusion from a simultaneous fit to the ATLAS and CMS data and compare our results with those obtained in global SMEFT analyses. |
2112.09473 | Fu-Hu Liu | Xu-Hong Zhang, Ya-Qin Gao, Fu-Hu Liu, Khusniddin K. Olimov | Thermal freeze-out parameters and pseudo-entropy from charged hadron
spectra in high energy collisions | 35 pages, 15 figures. Advances in High Energy Physics, accepted | Advances in High Energy Physics 2022, 7499093 (2022) (36 pages) | 10.1155/2022/7499093 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We collected the transverse momentum (mass) spectra of charged hadrons
($\pi^{-}$, $\pi^{+}$, $K^{-}$, $K^{+}$, $\overline{p}$, and $p$) produced in
collisions over a center-of-mass energy range from 2.70 to 200 GeV (per nucleon
pair). The modified Tsallis--Pareto-type function (the TP-like function) with
average transverse flow velocity is used to describe the contribution of
participant or constituent quarks to transverse momentum of considered hadron.
The experimental spectra of $\pi^{\mp}$ and $K^{\mp}$ (or $\overline{p}$ and
$p$) are fitted by the convolution of two (or three) TP-like functions due to
the fact that two (or three) constituent quarks are regarded as two (or three)
energy resources in the formation of considered hadron. From the reasonable
fits to the spectra, the thermal freeze-out parameters are extracted, and the
pseudo-entropy is newly defined and extracted. Some parameters quickly change
in the energy range of less than 7.7 GeV, and slowly change in the energy range
of greater than 7.7 GeV, indicating the variation of collision mechanism at
around 7.7 GeV.
| [
{
"created": "Fri, 17 Dec 2021 12:24:21 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Jan 2022 15:45:02 GMT",
"version": "v2"
},
{
"created": "Sat, 26 Feb 2022 13:51:09 GMT",
"version": "v3"
}
] | 2022-03-02 | [
[
"Zhang",
"Xu-Hong",
""
],
[
"Gao",
"Ya-Qin",
""
],
[
"Liu",
"Fu-Hu",
""
],
[
"Olimov",
"Khusniddin K.",
""
]
] | We collected the transverse momentum (mass) spectra of charged hadrons ($\pi^{-}$, $\pi^{+}$, $K^{-}$, $K^{+}$, $\overline{p}$, and $p$) produced in collisions over a center-of-mass energy range from 2.70 to 200 GeV (per nucleon pair). The modified Tsallis--Pareto-type function (the TP-like function) with average transverse flow velocity is used to describe the contribution of participant or constituent quarks to transverse momentum of considered hadron. The experimental spectra of $\pi^{\mp}$ and $K^{\mp}$ (or $\overline{p}$ and $p$) are fitted by the convolution of two (or three) TP-like functions due to the fact that two (or three) constituent quarks are regarded as two (or three) energy resources in the formation of considered hadron. From the reasonable fits to the spectra, the thermal freeze-out parameters are extracted, and the pseudo-entropy is newly defined and extracted. Some parameters quickly change in the energy range of less than 7.7 GeV, and slowly change in the energy range of greater than 7.7 GeV, indicating the variation of collision mechanism at around 7.7 GeV. |
2309.03281 | Pedro de la Torre Luque | Pedro De La Torre Luque, Juri Smirnov and Tim Linden | Gamma-Ray Lines in 15 Years of Fermi-LAT Data: New Constraints on Higgs
Portal Dark Matter | 12 pages, 9 figures | null | null | null | hep-ph astro-ph.HE | http://creativecommons.org/licenses/by/4.0/ | Monoenergetic $\gamma$-ray spectral lines are among the cleanest signatures
of dark matter annihilation. We analyze 15 years of Fermi-LAT data, find no
spectral lines, and place strong constraints on dark matter annihilation to
monoenergetic $\gamma$-rays. Additionally, we produce the first double-line
analysis of the coupled signals from $\gamma\gamma$ and $Z \gamma$ lines, which
proves particularly powerful for dark matter masses above $\sim150$~GeV. From
our constraints on a double-line feature, we investigate and constrain some
minimal models where the Galactic Center Excess (GCE) can be fit by dark matter
annihilation through the Higgs boson into Standard Model particles.
| [
{
"created": "Wed, 6 Sep 2023 18:00:30 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Sep 2023 09:48:54 GMT",
"version": "v2"
}
] | 2023-09-12 | [
[
"Luque",
"Pedro De La Torre",
""
],
[
"Smirnov",
"Juri",
""
],
[
"Linden",
"Tim",
""
]
] | Monoenergetic $\gamma$-ray spectral lines are among the cleanest signatures of dark matter annihilation. We analyze 15 years of Fermi-LAT data, find no spectral lines, and place strong constraints on dark matter annihilation to monoenergetic $\gamma$-rays. Additionally, we produce the first double-line analysis of the coupled signals from $\gamma\gamma$ and $Z \gamma$ lines, which proves particularly powerful for dark matter masses above $\sim150$~GeV. From our constraints on a double-line feature, we investigate and constrain some minimal models where the Galactic Center Excess (GCE) can be fit by dark matter annihilation through the Higgs boson into Standard Model particles. |
hep-ph/0502166 | Igor Shovkovy | Andreas Schmitt, Igor A. Shovkovy and Qun Wang | Pulsar kicks via spin-1 color superconductivity | 4 pages, 2 figures. Erratum added | Phys.Rev.Lett. 94 (2005) 211101 | 10.1103/PhysRevLett.94.211101 | null | hep-ph astro-ph hep-th nucl-th | null | We propose a new neutrino propulsion mechanism for neutron stars which can
lead to strong velocity kicks, needed to explain the observed bimodal velocity
distribution of pulsars. The spatial asymmetry in the neutrino emission is
naturally provided by a stellar core containing spin-1 color-superconducting
quark matter in the A phase. The neutrino propulsion mechanism switches on when
the stellar core temperature drops below the transition temperature of this
phase.
| [
{
"created": "Fri, 18 Feb 2005 08:43:17 GMT",
"version": "v1"
},
{
"created": "Tue, 17 May 2005 18:29:59 GMT",
"version": "v2"
},
{
"created": "Tue, 4 Oct 2005 09:23:16 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Schmitt",
"Andreas",
""
],
[
"Shovkovy",
"Igor A.",
""
],
[
"Wang",
"Qun",
""
]
] | We propose a new neutrino propulsion mechanism for neutron stars which can lead to strong velocity kicks, needed to explain the observed bimodal velocity distribution of pulsars. The spatial asymmetry in the neutrino emission is naturally provided by a stellar core containing spin-1 color-superconducting quark matter in the A phase. The neutrino propulsion mechanism switches on when the stellar core temperature drops below the transition temperature of this phase. |
0712.3201 | Pietro Falgari | P. Falgari | Four-fermion production near the W-pair production threshold | To appear in the proceedings of the 8th International Symposium on
Radiative Corrections, October 1-5, 2007, Florence, Italy | PoSRADCOR2007:003,2007 | null | PITHA 07/22, SFB/CPP-07-91 | hep-ph | null | I report on recent results for the total production cross section of the
process e- e+ -> mu- nubar_mu u dbar X near the W-pair production threshold up
to next-to-leading order in GammaW/MW alpha v^2 obtained in the framework of
unstable-particle effective field theory. Remaining theoretical uncertainties
and their impact on the experimental determination of the W mass are discussed.
| [
{
"created": "Wed, 19 Dec 2007 14:35:27 GMT",
"version": "v1"
}
] | 2009-04-14 | [
[
"Falgari",
"P.",
""
]
] | I report on recent results for the total production cross section of the process e- e+ -> mu- nubar_mu u dbar X near the W-pair production threshold up to next-to-leading order in GammaW/MW alpha v^2 obtained in the framework of unstable-particle effective field theory. Remaining theoretical uncertainties and their impact on the experimental determination of the W mass are discussed. |
1105.1433 | Tuomas Hapola | Jeppe R. Andersen, Tuomas Hapola and Francesco Sannino | W' and Z' limits for Minimal Walking Technicolor | 6 pages, 1 figure, v2: references added, table added | null | 10.1103/PhysRevD.85.055017 | CP3-Origins-2011-16; DIAS-2011-02 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We interpret the recent data on non-observation of Z'- and W'-bosons,
reported by CMS, within Minimal Walking Technicolor models and use them to
constrain the couplings and spectrum of the theory. We provide the reach for
both exclusion and possible observation for the LHC with 5 fb^-1 at 7 TeV in
the centre of mass energy, and 100 fb^-1 at 13 TeV.
| [
{
"created": "Sat, 7 May 2011 10:51:12 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Oct 2011 08:43:58 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Andersen",
"Jeppe R.",
""
],
[
"Hapola",
"Tuomas",
""
],
[
"Sannino",
"Francesco",
""
]
] | We interpret the recent data on non-observation of Z'- and W'-bosons, reported by CMS, within Minimal Walking Technicolor models and use them to constrain the couplings and spectrum of the theory. We provide the reach for both exclusion and possible observation for the LHC with 5 fb^-1 at 7 TeV in the centre of mass energy, and 100 fb^-1 at 13 TeV. |
1305.2988 | Yun Jiang | Yun Jiang | 125 GeV Higgs bosons in two-Higgs-doublet models | 4 pages, 3 figures, contributed to Proceedings of the conference
"Rencontres de Moriond EW 2013", La Thuile, Italy, 2-9 Mar. 2013 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Moriond 2013 ALTAS data at 125 GeV state appears to exhibit a substantial
excess in the di-photon final state and in the ZZ decaying to four lepton
channel, whereas which are more or less SM-like rate observed by CMS MVA
analysis. We examine the maximum Higgs signal enhancements that can be achieved
in the 2HDM when either a single Higgs or more than one Higgs have mass(es)
near 125 GeV. In general, the constraints of vacuum stability, unitarity and
perturbativity play the key role in restricting possibilities of signal
enhancement. The Type II model allows for an enhancement in the di-photon rate
(relative to the SM) of the order of 2-3 but associated with an even larger ZZ
or too large \tau\tau signal. In contrast, the maximal value of the di-photon
signal in the Type I model can reach the order of 1.3 for which the ZZ signal
is of order 1.
| [
{
"created": "Tue, 14 May 2013 01:08:37 GMT",
"version": "v1"
}
] | 2013-05-15 | [
[
"Jiang",
"Yun",
""
]
] | Moriond 2013 ALTAS data at 125 GeV state appears to exhibit a substantial excess in the di-photon final state and in the ZZ decaying to four lepton channel, whereas which are more or less SM-like rate observed by CMS MVA analysis. We examine the maximum Higgs signal enhancements that can be achieved in the 2HDM when either a single Higgs or more than one Higgs have mass(es) near 125 GeV. In general, the constraints of vacuum stability, unitarity and perturbativity play the key role in restricting possibilities of signal enhancement. The Type II model allows for an enhancement in the di-photon rate (relative to the SM) of the order of 2-3 but associated with an even larger ZZ or too large \tau\tau signal. In contrast, the maximal value of the di-photon signal in the Type I model can reach the order of 1.3 for which the ZZ signal is of order 1. |
hep-ph/0101274 | Boos Edward E. | E.E. Boos | Gauge Invariant Classes of Feynman Diagrams and Applications for
Calculations | To appear in the Proceedings of the Seventh International Workshop on
Advanced Computing and Analysis Technics in Physics Research (ACAT2000,
Fermilab, October 16-20, 2000); 3 pages | null | 10.1063/1.1405303 | null | hep-ph | null | In theories like SM or MSSM with a complex gauge group structure the complete
set of Feynman diagrams contributed to a particular physics process can be
splited to exact gauge invariant subsets. Arguments and examples given in the
review demonstrate that in many cases computations and analysis of the gauge
invariant subsets are important.
| [
{
"created": "Wed, 24 Jan 2001 11:25:37 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Boos",
"E. E.",
""
]
] | In theories like SM or MSSM with a complex gauge group structure the complete set of Feynman diagrams contributed to a particular physics process can be splited to exact gauge invariant subsets. Arguments and examples given in the review demonstrate that in many cases computations and analysis of the gauge invariant subsets are important. |
2303.17744 | Zachary Bogorad | Zachary Bogorad and Peter W. Graham and Giorgio Gratta | Detecting Nanometer-Scale New Forces with Coherent Neutron Scattering | 42 pages, 7 figures | Physical Review D 108 (2023) 055005 | 10.1103/PhysRevD.108.055005 | null | hep-ph hep-ex nucl-ex | http://creativecommons.org/licenses/by/4.0/ | Significant effort has been devoted to searching for new fundamental forces
of nature. At short length scales (below approximately 10 nm), the strongest
experimental constraints come from neutron scattering from individual nuclei in
gases. The leading experiments at longer length scales instead measure forces
between macroscopic test masses. We propose a hybrid of these two approaches:
scattering neutrons off of a target that has spatial structure at nanoscopic
length scales. Such structures will give a coherent enhancement to small-angle
scattering, where the new force is most significant. This can considerably
improve the sensitivity of neutron scattering experiments for new forces in the
0.1 - 100 nm range. We discuss the backgrounds due to Standard Model
interactions and a variety of potential target structures that could be used,
estimating the resulting sensitivities. We show that, using only one day of
beam time at a modern neutron scattering facility, our proposal has the
potential to detect new forces as much as two orders of magnitude beyond
current laboratory constraints at the appropriate length scales.
| [
{
"created": "Thu, 30 Mar 2023 23:34:10 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Sep 2023 00:39:29 GMT",
"version": "v2"
}
] | 2023-09-11 | [
[
"Bogorad",
"Zachary",
""
],
[
"Graham",
"Peter W.",
""
],
[
"Gratta",
"Giorgio",
""
]
] | Significant effort has been devoted to searching for new fundamental forces of nature. At short length scales (below approximately 10 nm), the strongest experimental constraints come from neutron scattering from individual nuclei in gases. The leading experiments at longer length scales instead measure forces between macroscopic test masses. We propose a hybrid of these two approaches: scattering neutrons off of a target that has spatial structure at nanoscopic length scales. Such structures will give a coherent enhancement to small-angle scattering, where the new force is most significant. This can considerably improve the sensitivity of neutron scattering experiments for new forces in the 0.1 - 100 nm range. We discuss the backgrounds due to Standard Model interactions and a variety of potential target structures that could be used, estimating the resulting sensitivities. We show that, using only one day of beam time at a modern neutron scattering facility, our proposal has the potential to detect new forces as much as two orders of magnitude beyond current laboratory constraints at the appropriate length scales. |
1104.4340 | Walter Grimus | W. Grimus and P.O. Ludl | Maximal atmospheric neutrino mixing from texture zeros and
quasi-degenerate neutrino masses | 14 pages, 2 figures | Phys.Lett.B700:356-361,2011 | 10.1016/j.physletb.2011.05.029 | UWThPh-2011-14 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is well-known that, in the basis where the charged-lepton mass matrix is
diagonal, there are seven cases of two texture zeros in Majorana neutrino mass
matrices that are compatible with all experimental data. We show that two of
these cases, namely B3 and B4 in the classification of Frampton, Glashow and
Marfatia, are special in the sense that they automatically lead to near-maximal
atmospheric neutrino mixing in the limit of a quasi-degenerate neutrino mass
spectrum. This property holds true irrespective of the values of the solar and
reactor mixing angles because, for these two cases, in the limit of a
quasi-degenerate spectrum, the second and third row of the lepton mixing matrix
are, up to signs, approximately complex-conjugate to each other. Moreover, in
the same limit the aforementioned cases also develop a maximal CP-violating
CKM-type phase, provided the reactor mixing angle is not too small.
| [
{
"created": "Thu, 21 Apr 2011 19:50:36 GMT",
"version": "v1"
}
] | 2011-06-07 | [
[
"Grimus",
"W.",
""
],
[
"Ludl",
"P. O.",
""
]
] | It is well-known that, in the basis where the charged-lepton mass matrix is diagonal, there are seven cases of two texture zeros in Majorana neutrino mass matrices that are compatible with all experimental data. We show that two of these cases, namely B3 and B4 in the classification of Frampton, Glashow and Marfatia, are special in the sense that they automatically lead to near-maximal atmospheric neutrino mixing in the limit of a quasi-degenerate neutrino mass spectrum. This property holds true irrespective of the values of the solar and reactor mixing angles because, for these two cases, in the limit of a quasi-degenerate spectrum, the second and third row of the lepton mixing matrix are, up to signs, approximately complex-conjugate to each other. Moreover, in the same limit the aforementioned cases also develop a maximal CP-violating CKM-type phase, provided the reactor mixing angle is not too small. |
hep-ph/9711299 | Mike Teper | M. Teper (Oxford) | What lattice calculations tell us about the glueball spectrum | LaTeX. Self-unpacking, tar-compressed file | null | null | OUTP-97-66P | hep-ph hep-lat | null | I review what lattice QCD simulations have to tell us about the glueball
spectrum. Talk given at HEP97, Jerusalem, August 1997.
| [
{
"created": "Wed, 12 Nov 1997 10:00:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Teper",
"M.",
"",
"Oxford"
]
] | I review what lattice QCD simulations have to tell us about the glueball spectrum. Talk given at HEP97, Jerusalem, August 1997. |
hep-ph/0402093 | Celso de Camargo Barros Junior | C.C. Barros Jr | $\pi \Lambda$ phase shifts and CP Violation in ${\Xi\to \pi \Lambda}$
Deca | 5 pages, 2 figures | null | null | null | hep-ph | null | The CP violation asymmetry parameters in $\Xi \to\pi\Lambda$ nonleptonic
decays are presently being measured by the HyperCP experiment. In the study of
these CP violation parameters, the strong $S$ and $P$ phase shifts for the
$\pi\Lambda$ final-state interactions are needed. In this work, these phases
are calculated using an effective chiral Lagrangian model, that considers
$\Sigma$, $\Sigma^*$(1385), and the $\sigma$-term, in the intermediate states.
The $\sigma$-term is calculated in terms of the scalar form factor of the
baryon.
| [
{
"created": "Mon, 9 Feb 2004 18:50:28 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Barros",
"C. C.",
"Jr"
]
] | The CP violation asymmetry parameters in $\Xi \to\pi\Lambda$ nonleptonic decays are presently being measured by the HyperCP experiment. In the study of these CP violation parameters, the strong $S$ and $P$ phase shifts for the $\pi\Lambda$ final-state interactions are needed. In this work, these phases are calculated using an effective chiral Lagrangian model, that considers $\Sigma$, $\Sigma^*$(1385), and the $\sigma$-term, in the intermediate states. The $\sigma$-term is calculated in terms of the scalar form factor of the baryon. |
0806.2267 | Ivan Schmidt | Alfredo Vega Ivan Schmidt | Scalar hadrons in $AdS_{5} \times S^{5}$ | 5 pages, 3 figures | Phys.Rev.D78:017703,2008 | 10.1103/PhysRevD.78.017703 | USM-TH-233 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A holographic model is presented, which allows to describe scalar hadrons
with an arbitrary number of constituents.
| [
{
"created": "Fri, 13 Jun 2008 15:24:52 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Schmidt",
"Alfredo Vega Ivan",
""
]
] | A holographic model is presented, which allows to describe scalar hadrons with an arbitrary number of constituents. |
hep-ph/9901251 | Anne Davis | A.C. Davis (DAMTP, U of Cambridge) | Cosmic Strings in Realistic Particle Physics Theories and Baryogensis | 20 pages; Presented at Peyresq Physics 3, July 1998 | Int.J.Theor.Phys.38:2867-2888,1999 | 10.1023/A:1026695729452 | DAMTP-99-9 | hep-ph | null | Grand unified theories can admit cosmic strings with fermion zero modes. Such
zero modes result in the string being current-carrying and the formation of
stable remnants, vortons. However, the string zero modes do not automaticall
survive subsequent phase transitions. In this case the vortons dissipate. It is
possible that the dissipating cosmic vortons create the observed baryon
asymmetry of the universe. We show that fermion zero modes are an automatic
consequence cosmic strings in supersymmetric theories. Since supersymmetry is
not observed in nature, we consider possible supersymmetry breaking terms. Some
of these terms result in the zero modes being destroyed. We calculate the
baryon asymmetry generated by the consequent dissipating cosmic vortons. If the
supersymmtry breaking scale is high enough, then the dissipating cosmic vortons
could account for the observed baryon asymmetry.
| [
{
"created": "Fri, 8 Jan 1999 10:56:03 GMT",
"version": "v1"
}
] | 2011-03-02 | [
[
"Davis",
"A. C.",
"",
"DAMTP, U of Cambridge"
]
] | Grand unified theories can admit cosmic strings with fermion zero modes. Such zero modes result in the string being current-carrying and the formation of stable remnants, vortons. However, the string zero modes do not automaticall survive subsequent phase transitions. In this case the vortons dissipate. It is possible that the dissipating cosmic vortons create the observed baryon asymmetry of the universe. We show that fermion zero modes are an automatic consequence cosmic strings in supersymmetric theories. Since supersymmetry is not observed in nature, we consider possible supersymmetry breaking terms. Some of these terms result in the zero modes being destroyed. We calculate the baryon asymmetry generated by the consequent dissipating cosmic vortons. If the supersymmtry breaking scale is high enough, then the dissipating cosmic vortons could account for the observed baryon asymmetry. |
1506.04811 | Yasuhito Sakaki | Yasuhito Sakaki | Evolution variable dependence of jet substructure | 16 pages, 7 figures | null | 10.1007/JHEP08(2015)100 | KEK-TH-1829 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Studies on jet substructure have evolved significantly in recent years. Jet
substructure is essentially determined by QCD radiations and non-perturbative
effects. Predictions of jet substructure are usually different among Monte
Carlo event generators, and are governed by the parton shower algorithm
implemented. For leading logarithmic parton shower, even though one of the core
variables is the evolution variable, its choice is not unique. We examine
evolution variable dependence of the jet substructure by developing a parton
shower generator that interpolates between different evolution variables using
a parameter $\alpha$. Jet shape variables and associated jet rates for quark
and gluon jets are used to demonstrate the $\alpha$-dependence of the jet
substructure. We find angular ordered shower predicts wider jets, while
relative transverse momentum ($p_{\bot}$) ordered shower predicts narrower
jets. This is qualitatively in agreement with the missing phase space of
$p_{\bot}$ ordered showers. Such difference can be reduced by tuning other
parameters of the showering algorithm, especially in the low energy region,
while the difference tends to increase for high energy jets.
| [
{
"created": "Tue, 16 Jun 2015 01:14:35 GMT",
"version": "v1"
}
] | 2015-09-30 | [
[
"Sakaki",
"Yasuhito",
""
]
] | Studies on jet substructure have evolved significantly in recent years. Jet substructure is essentially determined by QCD radiations and non-perturbative effects. Predictions of jet substructure are usually different among Monte Carlo event generators, and are governed by the parton shower algorithm implemented. For leading logarithmic parton shower, even though one of the core variables is the evolution variable, its choice is not unique. We examine evolution variable dependence of the jet substructure by developing a parton shower generator that interpolates between different evolution variables using a parameter $\alpha$. Jet shape variables and associated jet rates for quark and gluon jets are used to demonstrate the $\alpha$-dependence of the jet substructure. We find angular ordered shower predicts wider jets, while relative transverse momentum ($p_{\bot}$) ordered shower predicts narrower jets. This is qualitatively in agreement with the missing phase space of $p_{\bot}$ ordered showers. Such difference can be reduced by tuning other parameters of the showering algorithm, especially in the low energy region, while the difference tends to increase for high energy jets. |
2407.05741 | Shu-Min Zhao | Long Ruan, Shu-Min Zhao, Ming-Yue Liu, Xing-Yu Han, Xi Wang, Xing-Xing
Dong | Transition magnetic moment about neutrinos | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper investigates the neutrino transition magnetic moment in the
$U(1)_X$SSM. $U(1)_X$SSM is the $U(1)$ extension of Minimal Supersymmetric
Standard Model (MSSM) and its local gauge group is extended to $SU(3)_C\times
SU(2)_L \times U(1)_Y\times U(1)_X$. To obtain this model, three singlet new
Higgs superfields and right-handed neutrinos are added to the MSSM, which can
explain the results of neutrino oscillation experiments. The neutrino
transition magnetic moment is induced by electroweak radiative corrections. By
applying effective Lagrangian method and on-shell scheme, we study the
associated Feynman diagrams and the transition magnetic moment of neutrinos in
the model. We fit experimental data for neutrino mass variances and mixing
angle. Based on the range of data selection, the influences of different
sensitive parameters on the results are analysed. The numerical analysis shows
that many parameters have an effect on the neutrino transition moment, such as
$g_X$, $M_2$, $\lambda_H$ and $g_{YX}$. For our numerical results, the order of
magnitude of $\mu_{ij}$ is between $10^{-20}$ and $10^{-19}$.
| [
{
"created": "Mon, 8 Jul 2024 08:47:51 GMT",
"version": "v1"
}
] | 2024-07-09 | [
[
"Ruan",
"Long",
""
],
[
"Zhao",
"Shu-Min",
""
],
[
"Liu",
"Ming-Yue",
""
],
[
"Han",
"Xing-Yu",
""
],
[
"Wang",
"Xi",
""
],
[
"Dong",
"Xing-Xing",
""
]
] | This paper investigates the neutrino transition magnetic moment in the $U(1)_X$SSM. $U(1)_X$SSM is the $U(1)$ extension of Minimal Supersymmetric Standard Model (MSSM) and its local gauge group is extended to $SU(3)_C\times SU(2)_L \times U(1)_Y\times U(1)_X$. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to the MSSM, which can explain the results of neutrino oscillation experiments. The neutrino transition magnetic moment is induced by electroweak radiative corrections. By applying effective Lagrangian method and on-shell scheme, we study the associated Feynman diagrams and the transition magnetic moment of neutrinos in the model. We fit experimental data for neutrino mass variances and mixing angle. Based on the range of data selection, the influences of different sensitive parameters on the results are analysed. The numerical analysis shows that many parameters have an effect on the neutrino transition moment, such as $g_X$, $M_2$, $\lambda_H$ and $g_{YX}$. For our numerical results, the order of magnitude of $\mu_{ij}$ is between $10^{-20}$ and $10^{-19}$. |
0712.2454 | Yasunori Nomura | Lawrence J. Hall and Yasunori Nomura | Evidence for the Multiverse in the Standard Model and Beyond | 79 pages, 23 figures | Phys.Rev.D78:035001,2008 | 10.1103/PhysRevD.78.035001 | UCB-PTH-07/26 | hep-ph astro-ph hep-th | null | In any theory it is unnatural if the observed parameters lie very close to
special values that determine the existence of complex structures necessary for
observers. A naturalness probability, P, is introduced to numerically evaluate
the unnaturalness. If P is small in all known theories, there is an observer
naturalness problem. In addition to the well-known case of the cosmological
constant, we argue that nuclear stability and electroweak symmetry breaking
(EWSB) represent significant observer naturalness problems. The naturalness
probability associated with nuclear stability is conservatively estimated as
P_nuc < 10^{-(3-2)}, and for simple EWSB theories P_EWSB < 10^{-(2-1)}. This
pattern of unnaturalness in three different arenas, cosmology, nuclear physics,
and EWSB, provides evidence for the multiverse. In the nuclear case the problem
is largely solved even with a flat multiverse distribution, and with nontrivial
distributions it is possible to understand both the proximity to neutron
stability and the values of m_e and m_d - m_u in terms of the electromagnetic
contribution to the proton mass. It is reasonable that multiverse distributions
are strong functions of Lagrangian parameters due to their dependence on
various factors. In any EWSB theory, strongly varying distributions typically
lead to a little or large hierarchy, and in certain multiverses the size of the
little hierarchy is enhanced by a loop factor. Since the correct theory of EWSB
is unknown, our estimate for P_EWSB is theoretical. The LHC will determine
P_EWSB more robustly, which may remove or strengthen the observer naturalness
problem of EWSB. For each of the three arenas, the discovery of a natural
theory would eliminate the evidence for the multiverse; but in the absence of
such a theory, the multiverse provides a provisional understanding of the data.
| [
{
"created": "Mon, 17 Dec 2007 14:43:08 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Hall",
"Lawrence J.",
""
],
[
"Nomura",
"Yasunori",
""
]
] | In any theory it is unnatural if the observed parameters lie very close to special values that determine the existence of complex structures necessary for observers. A naturalness probability, P, is introduced to numerically evaluate the unnaturalness. If P is small in all known theories, there is an observer naturalness problem. In addition to the well-known case of the cosmological constant, we argue that nuclear stability and electroweak symmetry breaking (EWSB) represent significant observer naturalness problems. The naturalness probability associated with nuclear stability is conservatively estimated as P_nuc < 10^{-(3-2)}, and for simple EWSB theories P_EWSB < 10^{-(2-1)}. This pattern of unnaturalness in three different arenas, cosmology, nuclear physics, and EWSB, provides evidence for the multiverse. In the nuclear case the problem is largely solved even with a flat multiverse distribution, and with nontrivial distributions it is possible to understand both the proximity to neutron stability and the values of m_e and m_d - m_u in terms of the electromagnetic contribution to the proton mass. It is reasonable that multiverse distributions are strong functions of Lagrangian parameters due to their dependence on various factors. In any EWSB theory, strongly varying distributions typically lead to a little or large hierarchy, and in certain multiverses the size of the little hierarchy is enhanced by a loop factor. Since the correct theory of EWSB is unknown, our estimate for P_EWSB is theoretical. The LHC will determine P_EWSB more robustly, which may remove or strengthen the observer naturalness problem of EWSB. For each of the three arenas, the discovery of a natural theory would eliminate the evidence for the multiverse; but in the absence of such a theory, the multiverse provides a provisional understanding of the data. |
1109.3590 | Johann Haidenbauer | J. Haidenbauer and Ulf-G. Mei{\ss}ner | To bind or not to bind: The H-dibaryon in light of chiral effective
field theory | 8 pages, 2 figures; Results updated to the new H binding energy
reported by NPLQCD, conclusions remain unchanged, several references added | null | 10.1016/j.physletb.2011.10.070 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyse the quark mass dependence of the binding energy of the H-dibaryon
in the framework of chiral effective field theory. We show that the SU(3)
breaking effects induced by the differences of the pertinent two-baryon
thresholds (Lambda-Lambda, Xi-N, Sigma-Sigma) have a very pronounced impact
that need to be incorporated properly in future lattice QCD simulations. We
also point out that if the H-dibaryon is a two-baryon bound state, its dominant
component is Xi-N rather than Lambda-Lambda, which is a consequence of the
approximate SU(3) flavor symmetry of the two-baryon interactions.
| [
{
"created": "Fri, 16 Sep 2011 11:52:13 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Sep 2011 12:54:09 GMT",
"version": "v2"
}
] | 2015-05-30 | [
[
"Haidenbauer",
"J.",
""
],
[
"Meißner",
"Ulf-G.",
""
]
] | We analyse the quark mass dependence of the binding energy of the H-dibaryon in the framework of chiral effective field theory. We show that the SU(3) breaking effects induced by the differences of the pertinent two-baryon thresholds (Lambda-Lambda, Xi-N, Sigma-Sigma) have a very pronounced impact that need to be incorporated properly in future lattice QCD simulations. We also point out that if the H-dibaryon is a two-baryon bound state, its dominant component is Xi-N rather than Lambda-Lambda, which is a consequence of the approximate SU(3) flavor symmetry of the two-baryon interactions. |
0708.2033 | Alexei P. Martynenko | A. P. Martynenko | Ground-state triply and doubly heavy baryons in a relativistic
three-quark model | 10 pages, 2 figures, LaTex | Phys.Lett.B663:317-321,2008 | 10.1016/j.physletb.2008.04.030 | SSU-HEP-07/8 | hep-ph | null | Mass spectra of the ground-state baryons consisting of three or two heavy (b
or c) and one light (u,d,s) quarks are calculated in the framework of the
relativistic quark model and the hyperspherical expansion. The predictions of
masses of the triply and doubly heavy baryons are obtained by employing the
perturbation theory for the spin-independent and spin-dependent parts of the
three-quark Hamiltonian.
| [
{
"created": "Wed, 15 Aug 2007 12:00:14 GMT",
"version": "v1"
},
{
"created": "Wed, 22 Aug 2007 11:15:18 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Martynenko",
"A. P.",
""
]
] | Mass spectra of the ground-state baryons consisting of three or two heavy (b or c) and one light (u,d,s) quarks are calculated in the framework of the relativistic quark model and the hyperspherical expansion. The predictions of masses of the triply and doubly heavy baryons are obtained by employing the perturbation theory for the spin-independent and spin-dependent parts of the three-quark Hamiltonian. |
1402.6732 | Oscar St{\aa}l | Oscar St{\aa}l | Prospects for Higgs boson scenarios beyond the Standard Model | 13 pages, 6 figures. Invited talk presented at the XXXIII
international symposium on Physics in Collision (PIC2013), Beijing, P.R.
China, 3-7 September 2013 | Int.J.Mod.Phys.Conf.Ser. 31 (2014) 1460289 | 10.1142/S2010194514602890 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The new particle recently discovered at the Large Hadron Collider has
properties compatible with those expected for the Standard Model (SM) Higgs
boson. However, this does not exclude the possibility that the discovered state
is of non-standard origin, as part of an elementary Higgs sector in an extended
model, or not at all a fundamental Higgs scalar. We review briefly the
motivations for Higgs boson scenarios beyond the SM, discuss the phenomenology
of several examples, and summarize the prospects and methods for studying
interesting models with non-standard Higgs sectors using current and future
data.
| [
{
"created": "Wed, 26 Feb 2014 22:29:59 GMT",
"version": "v1"
}
] | 2014-05-28 | [
[
"Stål",
"Oscar",
""
]
] | The new particle recently discovered at the Large Hadron Collider has properties compatible with those expected for the Standard Model (SM) Higgs boson. However, this does not exclude the possibility that the discovered state is of non-standard origin, as part of an elementary Higgs sector in an extended model, or not at all a fundamental Higgs scalar. We review briefly the motivations for Higgs boson scenarios beyond the SM, discuss the phenomenology of several examples, and summarize the prospects and methods for studying interesting models with non-standard Higgs sectors using current and future data. |
hep-ph/9412309 | John Terning | R.S. Chivukula, E.H. Simmons and J. Terning | Limits on the Ununified Standard Model | 14 pages, plain TeX, 2 postscript figures, figures also available at
http://smyrd.bu.edu/htfigs/figure.html | Phys.Lett.B346:284-290,1995 | 10.1016/0370-2693(94)00006-S | BUHEP-94-37 | hep-ph | null | The ununified standard model is an extension of the standard model that
contains separate electroweak gauge groups for quarks and leptons. When it was
originally proposed, data allowed the new gauge bosons to be quite light. We
use recent data from precision electroweak measurements to put stringent bounds
on the ununified standard model. In particular, at the 95% confidence level, we
find that the ununified gauge bosons must have masses above about 2 TeV.
| [
{
"created": "Sat, 2 Jul 1994 14:12:00 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Chivukula",
"R. S.",
""
],
[
"Simmons",
"E. H.",
""
],
[
"Terning",
"J.",
""
]
] | The ununified standard model is an extension of the standard model that contains separate electroweak gauge groups for quarks and leptons. When it was originally proposed, data allowed the new gauge bosons to be quite light. We use recent data from precision electroweak measurements to put stringent bounds on the ununified standard model. In particular, at the 95% confidence level, we find that the ununified gauge bosons must have masses above about 2 TeV. |
1509.04421 | J. P. Ma | J.P. Ma and C. Wang | QCD Factorization for Quarkonium Production in Hadron Collions at Low
Transverse Momentum | discussions and references are added. Published version on Phys. Rev.
D | Phys. Rev. D 93, 014025 (2016) | 10.1103/PhysRevD.93.014025 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Inclusive production of a quarkonium $\eta_{c,b}$ in hadron collisions at low
transverse momentum can be used to extract various
Transverse-Momentum-Dependent(TMD) gluon distributions of hadrons, provided the
TMD factorization for the process holds. The factorization involving
unpolarized TMD gluon distributions of unpolarized hadrons has been examined
with on-shell gluons at one-loop level. In this work we study the factorization
at one-loop level with diagram approach in the most general case, where all TMD
gluon distributions at leading twist are involved. We find that the
factorization holds and the perturbative effects are represented by one
perturbative coefficient. Since the initial gluons from hadrons are off-shell
in general, there exists the so-called super-leading region found recently. We
find that the contributions from this region can come from individual diagrams
at one-loop level, but they are cancelled in the sum. Our factorized result for
the differential cross-section is explicitly gauge-invariant.
| [
{
"created": "Tue, 15 Sep 2015 07:12:15 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Feb 2016 02:39:01 GMT",
"version": "v2"
}
] | 2016-02-03 | [
[
"Ma",
"J. P.",
""
],
[
"Wang",
"C.",
""
]
] | Inclusive production of a quarkonium $\eta_{c,b}$ in hadron collisions at low transverse momentum can be used to extract various Transverse-Momentum-Dependent(TMD) gluon distributions of hadrons, provided the TMD factorization for the process holds. The factorization involving unpolarized TMD gluon distributions of unpolarized hadrons has been examined with on-shell gluons at one-loop level. In this work we study the factorization at one-loop level with diagram approach in the most general case, where all TMD gluon distributions at leading twist are involved. We find that the factorization holds and the perturbative effects are represented by one perturbative coefficient. Since the initial gluons from hadrons are off-shell in general, there exists the so-called super-leading region found recently. We find that the contributions from this region can come from individual diagrams at one-loop level, but they are cancelled in the sum. Our factorized result for the differential cross-section is explicitly gauge-invariant. |
0909.4664 | Sven Heinemeyer | P. Bechtle, O. Brein, S. Heinemeyer, G. Weiglein, K. Williams | New HiggsBounds from LEP and the Tevatron | 4 pages, talk given at SUSY09, Boston, June 2009 | AIP Conf.Proc.1200:510-513,2010 | 10.1063/1.3327659 | DCPT/09/146, FREIBURG-PHENO-09-05, IPPP/09/73 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We review the program HiggsBounds that tests theoretical predictions of
models with arbitrary Higgs sectors against the exclusion bounds obtained from
the Higgs searches at LEP and the Tevatron. We explicitly list the bounds that
have been added after the first release of HiggsBounds.
| [
{
"created": "Fri, 25 Sep 2009 11:14:09 GMT",
"version": "v1"
}
] | 2015-05-14 | [
[
"Bechtle",
"P.",
""
],
[
"Brein",
"O.",
""
],
[
"Heinemeyer",
"S.",
""
],
[
"Weiglein",
"G.",
""
],
[
"Williams",
"K.",
""
]
] | We review the program HiggsBounds that tests theoretical predictions of models with arbitrary Higgs sectors against the exclusion bounds obtained from the Higgs searches at LEP and the Tevatron. We explicitly list the bounds that have been added after the first release of HiggsBounds. |
hep-ph/0411151 | Shaaban Khalil | Shaaban Khalil | Supersymmetric contributions to the CP asymmetry of the B --> phi K and
B --> eta' K | Invited review article for Mod. Phys. Lett. A. 12 pages, 5 figures. 2
refs. added | Mod.Phys.Lett.A19:2745-2756,2004; Afr.J.Math.Phys.1:101-107,2004 | 10.1142/S0217732304015907 | null | hep-ph | null | We analyse the CP asymmetry of the B --> phi K and B --> eta' K processes in
general supersymmetric models. We consider both gluino and chargino exchanges
in a model independent way by using the mass insertion approximation method. We
adopt the QCD factorization method for evaluating the corresponding hadronic
matrix elements. We show that chromomagnetic type of operator may play an
important role in accounting for the deviation of the mixing CP asymmetry
between B --> phi K and B --> J/psi K processes observed by Belle and BaBar
experiments. We also show that due to the different parity in the final states
of these processes, their supersymmetric contributions from the R-sector have
an opposite sign, which naturally explain the large deviation between their
asymmetries.
| [
{
"created": "Wed, 10 Nov 2004 21:16:42 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Nov 2004 12:44:24 GMT",
"version": "v2"
}
] | 2014-11-18 | [
[
"Khalil",
"Shaaban",
""
]
] | We analyse the CP asymmetry of the B --> phi K and B --> eta' K processes in general supersymmetric models. We consider both gluino and chargino exchanges in a model independent way by using the mass insertion approximation method. We adopt the QCD factorization method for evaluating the corresponding hadronic matrix elements. We show that chromomagnetic type of operator may play an important role in accounting for the deviation of the mixing CP asymmetry between B --> phi K and B --> J/psi K processes observed by Belle and BaBar experiments. We also show that due to the different parity in the final states of these processes, their supersymmetric contributions from the R-sector have an opposite sign, which naturally explain the large deviation between their asymmetries. |
1703.04164 | Alper Hayreter | Alper Hayreter, German Valencia | LHC constraints on color octet scalars | 16 pages, 9 figures (matches version accepted) | Phys. Rev. D 96, 035004 (2017) | 10.1103/PhysRevD.96.035004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We extract constraints on the parameter space of the MW model by comparing
the cross-sections for dijet, top-pair, dijet-pair, $t\bar t t \bar t$ and
$b\bar b b \bar b$ productions at the LHC with the strongest available
experimental limits from ATLAS or CMS at 8 or 13 TeV. Overall we find that
masses below 1 TeV have not been excluded for color octet scalars as it is
often claimed in the literature. The constraints that can be placed on coupling
constants are typically weaker than those from existing theoretical
considerations, with the exception of the parameter $\eta_D$.
| [
{
"created": "Sun, 12 Mar 2017 19:40:41 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Mar 2017 11:20:30 GMT",
"version": "v2"
},
{
"created": "Tue, 25 Jul 2017 08:52:25 GMT",
"version": "v3"
}
] | 2017-08-16 | [
[
"Hayreter",
"Alper",
""
],
[
"Valencia",
"German",
""
]
] | We extract constraints on the parameter space of the MW model by comparing the cross-sections for dijet, top-pair, dijet-pair, $t\bar t t \bar t$ and $b\bar b b \bar b$ productions at the LHC with the strongest available experimental limits from ATLAS or CMS at 8 or 13 TeV. Overall we find that masses below 1 TeV have not been excluded for color octet scalars as it is often claimed in the literature. The constraints that can be placed on coupling constants are typically weaker than those from existing theoretical considerations, with the exception of the parameter $\eta_D$. |
2105.06810 | Aaron C. Vincent | Neal Avis Kozar, Ashlee Caddell, Luke Fraser-Leach, Pat Scott, Aaron
C. Vincent | Capt'n General: A generalized stellar dark matter capture and heat
transport code | 9 pages, 2 figures. Loosely based on a talk presented at TOOLS2020.
Code available at: https://github.com/aaronvincent/captngen | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Capt'n General is a FORTRAN90 standalone package that can be used to compute
the capture and heat transport of dark matter in stars. It can compute capture
rates for constant, velocity and momentum-dependent DM-nucleon elastic
scattering cross sections, as well as non-relativistic effective operator
interactions. Capt'n General can be interfaced with the GAMBIT global fitting
codebase as well as stellar evolution simulation codes such as MESA.
| [
{
"created": "Fri, 14 May 2021 13:02:44 GMT",
"version": "v1"
}
] | 2021-05-17 | [
[
"Kozar",
"Neal Avis",
""
],
[
"Caddell",
"Ashlee",
""
],
[
"Fraser-Leach",
"Luke",
""
],
[
"Scott",
"Pat",
""
],
[
"Vincent",
"Aaron C.",
""
]
] | Capt'n General is a FORTRAN90 standalone package that can be used to compute the capture and heat transport of dark matter in stars. It can compute capture rates for constant, velocity and momentum-dependent DM-nucleon elastic scattering cross sections, as well as non-relativistic effective operator interactions. Capt'n General can be interfaced with the GAMBIT global fitting codebase as well as stellar evolution simulation codes such as MESA. |
hep-ph/9901432 | Kosuke Odagiri | K. Odagiri | Searching for heavy charged Higgs bosons in the neutrino-tau decay mode
at LHC | 23 pages, 6 figures | null | null | RAL-TR-1999-012 | hep-ph | null | We discuss the search for the heavy charged Higgs bosons H^\pm, implicitly of
the Minimal Supersymmetric Standard Model, in the tau-nu decay mode at the LHC.
Compared to the dominant decay mode H^\pm\to bt, the channel suffers from
suppression due to the branching ratio and the lack of direct mass
reconstruction, but the reduced QCD background makes it a feasible channel
especially in the large tan(beta) region. We study the production in `bt
fusion' via bg\to tH^-, and the leading irreducible background bg\to tW^-. Our
results indicate that for the H^\pm mass of greater than 200 GeV and up to 1
TeV and higher, they can be discovered in this channel for a vast range of the
parameter space, down to at least tan(beta)\sim3 and potentially the whole
range of tan(beta) down to 1.5 if the signal selection efficiency can be
improved fourfold. Our analysis is sensitive to top quark identification at
large rapidity, and should be supplemented with a full study including jet
showering and detector effects.
| [
{
"created": "Wed, 27 Jan 1999 19:06:03 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Feb 1999 16:16:09 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Odagiri",
"K.",
""
]
] | We discuss the search for the heavy charged Higgs bosons H^\pm, implicitly of the Minimal Supersymmetric Standard Model, in the tau-nu decay mode at the LHC. Compared to the dominant decay mode H^\pm\to bt, the channel suffers from suppression due to the branching ratio and the lack of direct mass reconstruction, but the reduced QCD background makes it a feasible channel especially in the large tan(beta) region. We study the production in `bt fusion' via bg\to tH^-, and the leading irreducible background bg\to tW^-. Our results indicate that for the H^\pm mass of greater than 200 GeV and up to 1 TeV and higher, they can be discovered in this channel for a vast range of the parameter space, down to at least tan(beta)\sim3 and potentially the whole range of tan(beta) down to 1.5 if the signal selection efficiency can be improved fourfold. Our analysis is sensitive to top quark identification at large rapidity, and should be supplemented with a full study including jet showering and detector effects. |
2205.02030 | David Yallup | David Yallup, Timo Jan{\ss}en, Steffen Schumann, Will Handley | Exploring phase space with Nested Sampling | Accepted for publication to EPJC, 20 pages, 10 figures | Eur. Phys. J. C, 82 8 (2022) 678 | 10.1140/epjc/s10052-022-10632-2 | MCNET-22-10 | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We present the first application of a Nested Sampling algorithm to explore
the high-dimensional phase space of particle collision events. We describe the
adaptation of the algorithm, designed to perform Bayesian inference
computations, to the integration of partonic scattering cross sections and the
generation of individual events distributed according to the corresponding
squared matrix element. As a first concrete example we consider gluon
scattering processes into 3-, 4- and 5-gluon final states and compare the
performance with established sampling techniques. Starting from a flat prior
distribution Nested Sampling outperforms the Vegas algorithm and achieves
results comparable to a dedicated multi-channel importance sampler. We outline
possible approaches to combine Nested Sampling with non-flat prior
distributions to further reduce the variance of integral estimates and to
increase unweighting efficiencies.
| [
{
"created": "Wed, 4 May 2022 12:41:00 GMT",
"version": "v1"
},
{
"created": "Mon, 8 Aug 2022 10:26:21 GMT",
"version": "v2"
}
] | 2022-08-09 | [
[
"Yallup",
"David",
""
],
[
"Janßen",
"Timo",
""
],
[
"Schumann",
"Steffen",
""
],
[
"Handley",
"Will",
""
]
] | We present the first application of a Nested Sampling algorithm to explore the high-dimensional phase space of particle collision events. We describe the adaptation of the algorithm, designed to perform Bayesian inference computations, to the integration of partonic scattering cross sections and the generation of individual events distributed according to the corresponding squared matrix element. As a first concrete example we consider gluon scattering processes into 3-, 4- and 5-gluon final states and compare the performance with established sampling techniques. Starting from a flat prior distribution Nested Sampling outperforms the Vegas algorithm and achieves results comparable to a dedicated multi-channel importance sampler. We outline possible approaches to combine Nested Sampling with non-flat prior distributions to further reduce the variance of integral estimates and to increase unweighting efficiencies. |
1808.08843 | Takhmasib Aliev | T.M.Aliev and S.Bilmis | Determination of $f_0 - a_0^0$ mixing angle from QCD sum rules | null | null | 10.1140/epja/i2018-12584-4 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By assuming that the $f_0$ and $a_0^0$ mesons are mixed states of the
two-quark - tetraquark, the mixing angle between them is estimated within QCD
sum rules method, and it is obtained that the mixing angle is $(6.03 \pm
0.08)^\circ$. Our prediction on mixing angle can be checked in further
experiments which can shed light on choosing the "right" structure of $f_0$ and
$a_0^0$ mesons.
| [
{
"created": "Mon, 27 Aug 2018 13:45:42 GMT",
"version": "v1"
}
] | 2018-09-26 | [
[
"Aliev",
"T. M.",
""
],
[
"Bilmis",
"S.",
""
]
] | By assuming that the $f_0$ and $a_0^0$ mesons are mixed states of the two-quark - tetraquark, the mixing angle between them is estimated within QCD sum rules method, and it is obtained that the mixing angle is $(6.03 \pm 0.08)^\circ$. Our prediction on mixing angle can be checked in further experiments which can shed light on choosing the "right" structure of $f_0$ and $a_0^0$ mesons. |
hep-ph/9905486 | Jin Min Yang | Jin Min Yang | R_b and R_l in MSSM without R-Parity | results updated | Eur.Phys.J.C20:553-562,2001 | 10.1007/s100520100691 | TU-566 | hep-ph | null | We examined Z\ell^+\ell^- and Zb\bar b couplings in the minimal
supersymmetric model (MSSM) with explicit R-parity violating interactions. We
found the top quark L-violating couplings \lambda'_{i3k} and B-violating
couplings \lambda''_{3j3} could give significant contributions through the top
quark loops. To accomadate the latest R_{\ell} data, \lambda'_{i3k} are suject
to stringent bounds, some of which can be much stronger than the current
bounds. Within the current perturbative unitarity bound of 1.25 for
\lambda''_{3j3}, the R_b value in R-violating MSSM agrees well with the
experimental data at $2\sigma$ level, but may lie outside the 1\sigma range
depending on the involved sfermion mass.
| [
{
"created": "Wed, 26 May 1999 07:06:26 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Oct 1999 10:14:16 GMT",
"version": "v2"
}
] | 2009-01-07 | [
[
"Yang",
"Jin Min",
""
]
] | We examined Z\ell^+\ell^- and Zb\bar b couplings in the minimal supersymmetric model (MSSM) with explicit R-parity violating interactions. We found the top quark L-violating couplings \lambda'_{i3k} and B-violating couplings \lambda''_{3j3} could give significant contributions through the top quark loops. To accomadate the latest R_{\ell} data, \lambda'_{i3k} are suject to stringent bounds, some of which can be much stronger than the current bounds. Within the current perturbative unitarity bound of 1.25 for \lambda''_{3j3}, the R_b value in R-violating MSSM agrees well with the experimental data at $2\sigma$ level, but may lie outside the 1\sigma range depending on the involved sfermion mass. |
1110.6163 | Seyed Yaser Ayazi | Seyed Yaser Ayazi and Mojtaba Mohammadi Najafabadi | Constraints on Randall-Sundrum model from top-antitop production at the
LHC | 17 pages, 6 figures | JHEP 1201 (2012) 111 | 10.1007/JHEP01(2012)111 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the top pair production cross section at the LHC in the context of
Randall-Sundrum model including the Kaluza-Klein (KK) excited gravitons. It is
shown that the recent measurement of the cross section of this process at the
LHC restricts the parameter space in Randall-Sundrum (RS) model considerably.
We show that the coupling parameter ($\frac{k}{\bar{M}_{pl}}$) is excluded by
this measurement from 0.03 to 0.22 depending on the mass of first KK excited
graviton ($m_1$). We also study the effect of KK excitations on the spin
correlation of the top pairs. It is shown that the spin asymmetry in $t\bar{t}$
events is sensitive to the RS model parameters with a reasonable choice of
model parameters.
| [
{
"created": "Thu, 27 Oct 2011 19:42:26 GMT",
"version": "v1"
},
{
"created": "Wed, 7 Dec 2011 11:53:32 GMT",
"version": "v2"
}
] | 2015-03-19 | [
[
"Ayazi",
"Seyed Yaser",
""
],
[
"Najafabadi",
"Mojtaba Mohammadi",
""
]
] | We study the top pair production cross section at the LHC in the context of Randall-Sundrum model including the Kaluza-Klein (KK) excited gravitons. It is shown that the recent measurement of the cross section of this process at the LHC restricts the parameter space in Randall-Sundrum (RS) model considerably. We show that the coupling parameter ($\frac{k}{\bar{M}_{pl}}$) is excluded by this measurement from 0.03 to 0.22 depending on the mass of first KK excited graviton ($m_1$). We also study the effect of KK excitations on the spin correlation of the top pairs. It is shown that the spin asymmetry in $t\bar{t}$ events is sensitive to the RS model parameters with a reasonable choice of model parameters. |
hep-ph/0701158 | Geraldine Servant | Christopher Dennis, Muge Karagoz Unel, Geraldine Servant and Jeff
Tseng | Multi-W Events at LHC from a Warped Extra Dimension with Custodial
Symmetry | 17 pages, 26 figures | null | null | null | hep-ph | null | Randall-Sundrum models based on SU(2)_L * SU(2)_R with custodial symmetry are
compelling frameworks for building alternative models of electroweak symmetry
breaking. A particular feature of these models is the likely presence of light
Kaluza-Klein fermions related to the right-handed top quark. These can be as
light as a few hundred GeV and still compatible with EW precision constraints.
In this article, we study the detectability of four-W final states at the LHC,
which arise from the pair-production and tW decay of light Kaluza-Klein bottom
quarks as well as light Kaluza-Klein quarks carrying electric charge 5/3.
| [
{
"created": "Fri, 19 Jan 2007 14:34:41 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Dennis",
"Christopher",
""
],
[
"Unel",
"Muge Karagoz",
""
],
[
"Servant",
"Geraldine",
""
],
[
"Tseng",
"Jeff",
""
]
] | Randall-Sundrum models based on SU(2)_L * SU(2)_R with custodial symmetry are compelling frameworks for building alternative models of electroweak symmetry breaking. A particular feature of these models is the likely presence of light Kaluza-Klein fermions related to the right-handed top quark. These can be as light as a few hundred GeV and still compatible with EW precision constraints. In this article, we study the detectability of four-W final states at the LHC, which arise from the pair-production and tW decay of light Kaluza-Klein bottom quarks as well as light Kaluza-Klein quarks carrying electric charge 5/3. |
1107.0978 | Martin Schmaltz | Gustavo Marques Tavares and Martin Schmaltz | Explaining the t-tbar asymmetry with a light axigluon | references added | null | 10.1103/PhysRevD.84.054008 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose an axigluon with mass between 400 and 450 GeV and flavor universal
couplings to quarks to explain the Tevatron t-tbar forward-backward asymmetry.
The model predicts a small negative asymmetry for t-tbar pairs with invariant
mass below 450 GeV and a large positive asymmetry above 450 GeV. The asymmetry
arises from interference between s-channel gluon and axigluon diagrams and
requires a relatively weakly coupled axigluon ($g_{a} = g_{qcd}/3$).
Axigluon-gluon interference does not contribute to the t-tbar cross section.
New contributions to the cross section arise only at fourth order in the
axigluon coupling and are very small for a sufficiently broad axigluon. Dijet
measurements do not significantly constrain the axigluon couplings. We propose
several possible UV completions of the phenomenological axigluon which explain
the required small couplings and large width. Such UV completions necessarily
contain new colored fermions or scalars below the axigluon mass and predict
multi-jet events with large cross sections at the Tevatron and LHC.
| [
{
"created": "Tue, 5 Jul 2011 20:07:18 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Jul 2011 19:44:10 GMT",
"version": "v2"
}
] | 2013-05-29 | [
[
"Tavares",
"Gustavo Marques",
""
],
[
"Schmaltz",
"Martin",
""
]
] | We propose an axigluon with mass between 400 and 450 GeV and flavor universal couplings to quarks to explain the Tevatron t-tbar forward-backward asymmetry. The model predicts a small negative asymmetry for t-tbar pairs with invariant mass below 450 GeV and a large positive asymmetry above 450 GeV. The asymmetry arises from interference between s-channel gluon and axigluon diagrams and requires a relatively weakly coupled axigluon ($g_{a} = g_{qcd}/3$). Axigluon-gluon interference does not contribute to the t-tbar cross section. New contributions to the cross section arise only at fourth order in the axigluon coupling and are very small for a sufficiently broad axigluon. Dijet measurements do not significantly constrain the axigluon couplings. We propose several possible UV completions of the phenomenological axigluon which explain the required small couplings and large width. Such UV completions necessarily contain new colored fermions or scalars below the axigluon mass and predict multi-jet events with large cross sections at the Tevatron and LHC. |
0902.3250 | Ivo de Medeiros Varzielas | Federica Bazzocchi, Ivo de Medeiros Varzielas | Tri-bi-maximal mixing in viable family symmetry unified model with
extended seesaw | 12 pages | Phys.Rev.D79:093001,2009 | 10.1103/PhysRevD.79.093001 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a Grand Unified model based on SO(10) with a Delta(27) family
symmetry. Fermion masses and mixings are fitted and agree well with
experimental values. An extended seesaw mechanism plays a key role in the
generation of the leptonic mixing, which is approximately tri-bi-maximal.
| [
{
"created": "Thu, 19 Feb 2009 17:51:56 GMT",
"version": "v1"
}
] | 2009-10-29 | [
[
"Bazzocchi",
"Federica",
""
],
[
"Varzielas",
"Ivo de Medeiros",
""
]
] | We present a Grand Unified model based on SO(10) with a Delta(27) family symmetry. Fermion masses and mixings are fitted and agree well with experimental values. An extended seesaw mechanism plays a key role in the generation of the leptonic mixing, which is approximately tri-bi-maximal. |
1506.08845 | Michael Russell | Andy Buckley, Christoph Englert, James Ferrando, David J. Miller, Liam
Moore, Michael Russell and Chris D. White | A global fit of top quark effective theory to data | Additional references and preprint code added. Minor error in
generation of plots fixed, no conclusions affected | Phys. Rev. D 92, 091501 (2015) | 10.1103/PhysRevD.92.091501 | GLAS-PPE/2015-04 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we present a global fit of beyond the Standard Model (BSM)
dimension six operators relevant to the top quark sector to currently available
data. Experimental measurements include parton-level top-pair and single top
production from the LHC and the Tevatron. Higher order QCD corrections are
modelled using differential and global K-factors, and we use novel fast-fitting
techniques developed in the context of Monte Carlo event generator tuning to
perform the fit. This allows us to provide new, fully correlated and
model-independent bounds on new physics effects in the top sector from the most
current direct hadron-collider measurements in light of the involved
theoretical and experimental systematics. As a by-product, our analysis
constitutes a proof-of-principle that fast fitting of theory to data is
possible in the top quark sector, and paves the way for a more detailed
analysis including top quark decays, detector corrections and precision
observables.
| [
{
"created": "Mon, 29 Jun 2015 20:19:24 GMT",
"version": "v1"
},
{
"created": "Mon, 30 Nov 2015 11:16:55 GMT",
"version": "v2"
}
] | 2015-12-02 | [
[
"Buckley",
"Andy",
""
],
[
"Englert",
"Christoph",
""
],
[
"Ferrando",
"James",
""
],
[
"Miller",
"David J.",
""
],
[
"Moore",
"Liam",
""
],
[
"Russell",
"Michael",
""
],
[
"White",
"Chris D.",
""
]
] | In this paper we present a global fit of beyond the Standard Model (BSM) dimension six operators relevant to the top quark sector to currently available data. Experimental measurements include parton-level top-pair and single top production from the LHC and the Tevatron. Higher order QCD corrections are modelled using differential and global K-factors, and we use novel fast-fitting techniques developed in the context of Monte Carlo event generator tuning to perform the fit. This allows us to provide new, fully correlated and model-independent bounds on new physics effects in the top sector from the most current direct hadron-collider measurements in light of the involved theoretical and experimental systematics. As a by-product, our analysis constitutes a proof-of-principle that fast fitting of theory to data is possible in the top quark sector, and paves the way for a more detailed analysis including top quark decays, detector corrections and precision observables. |
1302.3027 | Ilya Gorbunov N | G. A. Kozlov | To what extent should we find the chiral end point? | 16 pages | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We analyze the critical phenomena in the theory of strong interactions at
high temperatures starting from first principles. The model is based on the
dual Yang-Mills theory with scalar degrees of freedom - the dilatons. The
latter are produced due to the spontaneous breaking of an approximate scale
symmetry. The phase transitions are considered in systems where the field
conjugate to the order parameter has the (critical) chiral end mode. The hiral
end point (ChEP) is a distinct singular feature existence of which is dictated
by the chiral dynamics. The physical approach the effective ChEP is studied via
the influence fluctuations of two-body Bose-Einstein correlation function for
observed particles to which the chiral end mode couples.
| [
{
"created": "Wed, 13 Feb 2013 09:21:03 GMT",
"version": "v1"
}
] | 2013-02-14 | [
[
"Kozlov",
"G. A.",
""
]
] | We analyze the critical phenomena in the theory of strong interactions at high temperatures starting from first principles. The model is based on the dual Yang-Mills theory with scalar degrees of freedom - the dilatons. The latter are produced due to the spontaneous breaking of an approximate scale symmetry. The phase transitions are considered in systems where the field conjugate to the order parameter has the (critical) chiral end mode. The hiral end point (ChEP) is a distinct singular feature existence of which is dictated by the chiral dynamics. The physical approach the effective ChEP is studied via the influence fluctuations of two-body Bose-Einstein correlation function for observed particles to which the chiral end mode couples. |
2201.01802 | Walter Grimus | Walter Grimus | Notes on basis-independent computations with the Dirac algebra | 58 pages, no figures. Modifications in abstract, introduction and
conclusions, section about time reversal added, some formulas added at the
end of section 9, typos corrected | null | null | UWThPh-2021-14 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In these notes we first review Pauli's proof of his `fundamental theorem'
that states the equivalence of any two sets of Dirac matrices $\{ \gamma^\mu
\}$. Due to this theorem not only all physical results in the context of the
Dirac equation have to be independent of the basis chosen for the Dirac
matrices, but it should also be possible to obtain the results without
resorting to a specific basis in the course of the computation. Indeed, we
demonstrate this in the case of the behaviour of Dirac spinors under Lorentz
transformations, the quantization of the Dirac field, the expectation value of
the spin operator and several other topics. In particular, we emphasize the
totally different physics and mathematics background of the matrix $\beta$,
used in the definition of the conjugate Dirac spinor, and $\gamma^0$. Finally,
we compare the basis-independent manipulations with those performed in the Weyl
basis of Dirac matrices. The present notes provide a self-contained
introduction to the Dirac theory by solely exploiting the simplicity of the
Dirac algebra and the power of Pauli's Theorem.
| [
{
"created": "Thu, 2 Dec 2021 18:19:02 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Jan 2022 17:57:46 GMT",
"version": "v2"
},
{
"created": "Fri, 25 Feb 2022 16:00:58 GMT",
"version": "v3"
}
] | 2022-02-28 | [
[
"Grimus",
"Walter",
""
]
] | In these notes we first review Pauli's proof of his `fundamental theorem' that states the equivalence of any two sets of Dirac matrices $\{ \gamma^\mu \}$. Due to this theorem not only all physical results in the context of the Dirac equation have to be independent of the basis chosen for the Dirac matrices, but it should also be possible to obtain the results without resorting to a specific basis in the course of the computation. Indeed, we demonstrate this in the case of the behaviour of Dirac spinors under Lorentz transformations, the quantization of the Dirac field, the expectation value of the spin operator and several other topics. In particular, we emphasize the totally different physics and mathematics background of the matrix $\beta$, used in the definition of the conjugate Dirac spinor, and $\gamma^0$. Finally, we compare the basis-independent manipulations with those performed in the Weyl basis of Dirac matrices. The present notes provide a self-contained introduction to the Dirac theory by solely exploiting the simplicity of the Dirac algebra and the power of Pauli's Theorem. |
hep-ph/0001309 | Nicolao Fornengo | A. Bottino (Torino U.), F. Donato (LAPP-Annecy), N. Fornengo (Torino
U. and Valencia U.) and S. Scopel (Zaragoza U.) | Further investigation of a relic neutralino as a possible origin of an
annual-modulation effect in WIMP direct search | 29 pages, 12 figures, typeset with ReVTeX. In order to reduce size,
the version on the archive has low resolution figures. A full version of the
paper can be found at http://www.to.infn.it/~fornengo/papers/ | Phys.Rev.D62:056006,2000 | 10.1103/PhysRevD.62.056006 | DFTT 1/2000, IFIC/00-12, FTUV/00-11, LAPTH-779/2000 | hep-ph astro-ph | null | We analyze the annual-modulation effect, measured by the DAMA Collaboration
with the new implementation of a further two-years running, in the context of a
possible interpretation in terms of relic neutralinos. We impose over the set
of supersymmetric configurations, selected by the annual-modulation data, the
constraints derived from WIMP indirect measurements, and discuss the features
of the ensuing relic neutralinos. We critically discuss the sources of the main
theoretical uncertainties in the analysis of event rates for direct and
indirect WIMP searches.
| [
{
"created": "Sat, 29 Jan 2000 16:45:29 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Bottino",
"A.",
"",
"Torino U."
],
[
"Donato",
"F.",
"",
"LAPP-Annecy"
],
[
"Fornengo",
"N.",
"",
"Torino\n U. and Valencia U."
],
[
"Scopel",
"S.",
"",
"Zaragoza U."
]
] | We analyze the annual-modulation effect, measured by the DAMA Collaboration with the new implementation of a further two-years running, in the context of a possible interpretation in terms of relic neutralinos. We impose over the set of supersymmetric configurations, selected by the annual-modulation data, the constraints derived from WIMP indirect measurements, and discuss the features of the ensuing relic neutralinos. We critically discuss the sources of the main theoretical uncertainties in the analysis of event rates for direct and indirect WIMP searches. |
0912.1508 | XiaoHai Liu | Xiao-Hai Liu, Qiang Zhao | The evasion of helicity selection rule in $\chi_{c1}\to VV$ and
$\chi_{c2}\to VP$ via intermediate charmed meson loops | 9 pages, 5 figures; minor changes: modified introduction, references
added | Phys.Rev.D81:014017,2010 | 10.1103/PhysRevD.81.014017 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The hadronic decays of $\chi_{c1}\to VV$ and $\chi_{c2}\to VP$ are supposed
to be suppressed by the helicity selection rule in the pQCD framework. With an
effective Lagrangian method, we show that the intermediate charmed meson loops
can provide a mechanism for the evasion of the helicity selection rule, and
result in sizeable decay branching ratios in some of those channels. The
theoretical predictions can be examined by the forthcoming BES-III data in the
near future.
| [
{
"created": "Tue, 8 Dec 2009 14:26:07 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Dec 2009 03:21:05 GMT",
"version": "v2"
},
{
"created": "Thu, 21 Jan 2010 13:07:53 GMT",
"version": "v3"
}
] | 2010-04-06 | [
[
"Liu",
"Xiao-Hai",
""
],
[
"Zhao",
"Qiang",
""
]
] | The hadronic decays of $\chi_{c1}\to VV$ and $\chi_{c2}\to VP$ are supposed to be suppressed by the helicity selection rule in the pQCD framework. With an effective Lagrangian method, we show that the intermediate charmed meson loops can provide a mechanism for the evasion of the helicity selection rule, and result in sizeable decay branching ratios in some of those channels. The theoretical predictions can be examined by the forthcoming BES-III data in the near future. |
hep-ph/9602302 | Passarino Giampiero | Giampiero Passarino (Torino U. & INFN Torino) | WTO - a deterministic approach to $4$-fermion physics | 55 LaTex pages. Submitted to Comput. Phys. Comm | Comput.Phys.Commun. 97 (1996) 261-303 | 10.1016/0010-4655(96)00041-0 | null | hep-ph | null | The program WTO, which is designed for computing cross sections and other
relevant observables in the $e^+e^-$ annihilation into four fermions, is
described. The various quantities are computed over both a completely inclusive
experimental set-up and a realistic one, i.e. with cuts on the final state
energies, final state angles, scattering angles and final state invariant
masses. Initial state QED corrections are included by means of the structure
function approach while final state QCD corrections are applicable in their
{\it naive} formulation. A gauge restoring mechanism is included according to
the Fermion-Loop scheme. The program structure is highly modular and particular
care has been devoted to computing efficiency and speed.
| [
{
"created": "Wed, 14 Feb 1996 07:18:14 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Passarino",
"Giampiero",
"",
"Torino U. & INFN Torino"
]
] | The program WTO, which is designed for computing cross sections and other relevant observables in the $e^+e^-$ annihilation into four fermions, is described. The various quantities are computed over both a completely inclusive experimental set-up and a realistic one, i.e. with cuts on the final state energies, final state angles, scattering angles and final state invariant masses. Initial state QED corrections are included by means of the structure function approach while final state QCD corrections are applicable in their {\it naive} formulation. A gauge restoring mechanism is included according to the Fermion-Loop scheme. The program structure is highly modular and particular care has been devoted to computing efficiency and speed. |
1701.05839 | Ivan Vitev | Zhong-Bo Kang, Felix Ringer, Ivan Vitev | Inclusive production of small radius jets in heavy-ion collisions | 8 pages, 5 figures | Phys.Lett. B769 (2017) 242-248 | 10.1016/j.physletb.2017.03.067 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a new formalism to describe the inclusive production of small
radius jets in heavy-ion collisions, which is consistent with jet calculations
in the simpler proton-proton system. Only at next-to-leading order (NLO) and
beyond, the jet radius parameter $R$ and the jet algorithm dependence of the
jet cross section can be studied and a meaningful comparison to experimental
measurements is possible. We are able to consistently achieve NLO accuracy by
making use of the recently developed semi-inclusive jet functions within Soft
Collinear Effective Theory (SCET). In addition, single logarithms of the jet
size parameter $\alpha_s^n\ln^n R$ are resummed to next-to-leading logarithmic
(NLL$_R$) accuracy. The medium modified semi-inclusive jet functions are
obtained within the framework of SCET with Glauber gluons that describe the
interaction of jets with the medium. We present numerical results for the
suppression of inclusive jet cross sections in heavy ion collisions at the LHC
and the formalism developed here can be extended directly to corresponding jet
substructure observables.
| [
{
"created": "Fri, 20 Jan 2017 16:04:46 GMT",
"version": "v1"
}
] | 2017-04-07 | [
[
"Kang",
"Zhong-Bo",
""
],
[
"Ringer",
"Felix",
""
],
[
"Vitev",
"Ivan",
""
]
] | We develop a new formalism to describe the inclusive production of small radius jets in heavy-ion collisions, which is consistent with jet calculations in the simpler proton-proton system. Only at next-to-leading order (NLO) and beyond, the jet radius parameter $R$ and the jet algorithm dependence of the jet cross section can be studied and a meaningful comparison to experimental measurements is possible. We are able to consistently achieve NLO accuracy by making use of the recently developed semi-inclusive jet functions within Soft Collinear Effective Theory (SCET). In addition, single logarithms of the jet size parameter $\alpha_s^n\ln^n R$ are resummed to next-to-leading logarithmic (NLL$_R$) accuracy. The medium modified semi-inclusive jet functions are obtained within the framework of SCET with Glauber gluons that describe the interaction of jets with the medium. We present numerical results for the suppression of inclusive jet cross sections in heavy ion collisions at the LHC and the formalism developed here can be extended directly to corresponding jet substructure observables. |
1908.08603 | Carlotta Giusti | Carlotta Giusti, Martin V. Ivanov | Neutral Current Neutrino-Nucleus Scattering. Theory | 62 pages, 34 figures, JPG focus issue on Neutrino-Nucleus
Interactions | null | 10.1088/1361-6471/ab5251 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The treatment of nuclear effects in neutrino-nucleus interactions is one of
the main sources of systematic uncertainty for the analysis and interpretation
of data of neutrino oscillation experiments. Neutrinos interact with nuclei via
charged or neutral currents and both cases must be studied to obtain a complete
information. We give an overview of the theoretical work that has been done to
describe nuclear effects in neutral-current neutrin onucleus scattering in the
kinematic region ranging between beam energies of a few hundreds MeV to a few
GeV, which is typical of most ongoing and future accelerator-based neutrino
experiments, and where quasielastic scattering is the main interaction
mechanism. We review the current status and challenges of the theoretical
models, the role and relevance of the contributions of different nuclear
effects, and the present status of the comparison between the numerical
predictions of the models as well as the available experimental data. We
discuss also the sensitivity to the strange form factors of the nucleon and the
methods and observables that can allow one to obtain evidence for a possible
strange quark contribution from measurements of neutrino and
antineutrino-nucleus scattering.
| [
{
"created": "Thu, 22 Aug 2019 21:36:57 GMT",
"version": "v1"
}
] | 2020-01-29 | [
[
"Giusti",
"Carlotta",
""
],
[
"Ivanov",
"Martin V.",
""
]
] | The treatment of nuclear effects in neutrino-nucleus interactions is one of the main sources of systematic uncertainty for the analysis and interpretation of data of neutrino oscillation experiments. Neutrinos interact with nuclei via charged or neutral currents and both cases must be studied to obtain a complete information. We give an overview of the theoretical work that has been done to describe nuclear effects in neutral-current neutrin onucleus scattering in the kinematic region ranging between beam energies of a few hundreds MeV to a few GeV, which is typical of most ongoing and future accelerator-based neutrino experiments, and where quasielastic scattering is the main interaction mechanism. We review the current status and challenges of the theoretical models, the role and relevance of the contributions of different nuclear effects, and the present status of the comparison between the numerical predictions of the models as well as the available experimental data. We discuss also the sensitivity to the strange form factors of the nucleon and the methods and observables that can allow one to obtain evidence for a possible strange quark contribution from measurements of neutrino and antineutrino-nucleus scattering. |
hep-ph/9312216 | Makoto Oka | Takashi Inoue, Sachiko Takeuchi, and Makoto Oka | Weak $\Lam N\to NN$ Transition in the Direct Quark Mechanism | 15 pp. no figure, Talk presented by M.~Oka at {\sl the JSPS-NSF Joint
Seminar on "Hyperon Nucleon Interactions", Maui, HI, October, 1993 | null | null | TIT/HEP-240/NP | hep-ph nucl-th | null | The weak $\Lam N\to NN$ transition is studied in the valence quark model
approach. The momentum transfer for this transition is so large that the
short-distance two baryon dynamics must be taken into account. The two baryon
system is described in the quark cluster model and the weak transition
amplitude is calculated by evaluating the matrix elements of the effective weak
$\Delta S= 1$ hamiltonian. The results indicate some qualitative differences
when compared with those in conventional meson-exchange calculations.
Especially, we conclude that contributions of the $\Delta I={3\over2}$
transition are significant and that the discrepancy in the $n-p$ ratio between
theory and experiment could be resolved by including the direct-quark
processes.
| [
{
"created": "Fri, 3 Dec 1993 03:36:59 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Inoue",
"Takashi",
""
],
[
"Takeuchi",
"Sachiko",
""
],
[
"Oka",
"Makoto",
""
]
] | The weak $\Lam N\to NN$ transition is studied in the valence quark model approach. The momentum transfer for this transition is so large that the short-distance two baryon dynamics must be taken into account. The two baryon system is described in the quark cluster model and the weak transition amplitude is calculated by evaluating the matrix elements of the effective weak $\Delta S= 1$ hamiltonian. The results indicate some qualitative differences when compared with those in conventional meson-exchange calculations. Especially, we conclude that contributions of the $\Delta I={3\over2}$ transition are significant and that the discrepancy in the $n-p$ ratio between theory and experiment could be resolved by including the direct-quark processes. |
2209.13535 | Alessandro Guida | Simone Amoroso, Ludovica Aperio Bella, Maarten Boonekamp, Stefano
Camarda, Alexander Glazov, Alessandro Guida, Renat Sadykov and Yulia
Yermolchyk | Drell-Yan cross-sections with fiducial cuts: impact of linear power
corrections and $q_T$-resummation in PDF determination | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Measurement at Hadron colliders of neutral- and charged-current Drell-Yan
production provide essential constraints in the determination of parton
distribution functions. Experimentally, they have reached percent level
precision, challenging the accuracy of the theoretical predictions. In this
work we benchmark the novel implementation in $\texttt{DYTurbo}$ of linear
fiducial power corrections in the $q_T$-subtraction formalism at NLO and NNLO
in QCD. We illustrate how the inclusion of linear fiducial power corrections
impacts predictions for precise $W$ and $Z$ measurements from the LHC and
affects their description by modern global parton distribution functions. The
further inclusion of $q_T$-resummation corrections in the theoretical
predictions leads to a better modelling of the lepton $p_T$ distribution and we
study how this improve the description of the data.
| [
{
"created": "Tue, 27 Sep 2022 16:48:54 GMT",
"version": "v1"
}
] | 2022-09-28 | [
[
"Amoroso",
"Simone",
""
],
[
"Bella",
"Ludovica Aperio",
""
],
[
"Boonekamp",
"Maarten",
""
],
[
"Camarda",
"Stefano",
""
],
[
"Glazov",
"Alexander",
""
],
[
"Guida",
"Alessandro",
""
],
[
"Sadykov",
"Renat",
""
],
[
"Yermolchyk",
"Yulia",
""
]
] | Measurement at Hadron colliders of neutral- and charged-current Drell-Yan production provide essential constraints in the determination of parton distribution functions. Experimentally, they have reached percent level precision, challenging the accuracy of the theoretical predictions. In this work we benchmark the novel implementation in $\texttt{DYTurbo}$ of linear fiducial power corrections in the $q_T$-subtraction formalism at NLO and NNLO in QCD. We illustrate how the inclusion of linear fiducial power corrections impacts predictions for precise $W$ and $Z$ measurements from the LHC and affects their description by modern global parton distribution functions. The further inclusion of $q_T$-resummation corrections in the theoretical predictions leads to a better modelling of the lepton $p_T$ distribution and we study how this improve the description of the data. |
hep-ph/9807234 | Bodenmueller | Harald Fritzsch, Zhi-Zhong Xing | The Mixing of Quarks and Leptons and Neutrino Degeneracy | 10 latex pages | null | null | LMU 07/98 | hep-ph | null | In drawing on an analogy with the flavor mixing observed in the quark sector
we discuss a pattern of large flavor mixing angles in the lepton sector. Simple
arguments based on a democratic symmetry and its violation in the lepton sector
allow us to determine the flavor mixing matrix of leptons. The mixing angle
relevant for solar neutrino oscillations is maximal (close to $45^{\circ}$),
while the angle relevant for atmospheric neutrino oscillations is given by
$\sin^2 2 \theta = 8/9$. The emerging pattern is consistent with the results of
the solar and atmospheric neutrino experiments.
| [
{
"created": "Fri, 3 Jul 1998 09:44:52 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Fritzsch",
"Harald",
""
],
[
"Xing",
"Zhi-Zhong",
""
]
] | In drawing on an analogy with the flavor mixing observed in the quark sector we discuss a pattern of large flavor mixing angles in the lepton sector. Simple arguments based on a democratic symmetry and its violation in the lepton sector allow us to determine the flavor mixing matrix of leptons. The mixing angle relevant for solar neutrino oscillations is maximal (close to $45^{\circ}$), while the angle relevant for atmospheric neutrino oscillations is given by $\sin^2 2 \theta = 8/9$. The emerging pattern is consistent with the results of the solar and atmospheric neutrino experiments. |
1807.10319 | Bo-Qiang Ma | Mengyun Liu, Bo-Qiang Ma | Quark-antiquark asymmetry of helicity distributions in the nucleon sea | 10 latex pages, 5 figures, final version to appear in PRD | Phys. Rev. D 98, 036024 (2018) | 10.1103/PhysRevD.98.036024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the helicity distributions of light flavor quark-antiquark ($q
\bar{q}$) pairs in the nucleon sea. The valence quarks are handled by adopting
the light-cone SU(6) quark-spectator-diquark model and the sea $q \bar{q}$
pairs are treated from statistical consideration by introducing the helicity
suppression factors $l_q(x)$ and $\bar l_q(x)$ to parametrize the helicity
distributions of q-flavor sea quark and antiquark respectively, while $\Delta
l_q(x)=l_q(x)-\bar l_q(x)$ represents a combined effect of helicity
contribution due to sea $q \bar{q}$ pairs. From fitting the nucleon
polarization asymmetries $A^N_1$ in inclusive deep inelastic scattering
processes and the single-spin asymmetries $A^{W^{\pm}}_L$ in Drell-Yan type
processes, we find a significant asymmetry between the quark and antiquark
helicity distributions of the nucleon sea. Therefore the quark-antiquark
asymmetry of helicity distributions of nucleon sea $q \bar{q}$ pairs, i.e.,
$\Delta q_s(x) \neq \Delta \bar q_s(x)$, plays an important role for a
comprehensive understanding of the nucleon spin content.
| [
{
"created": "Thu, 26 Jul 2018 18:50:21 GMT",
"version": "v1"
},
{
"created": "Tue, 14 Aug 2018 14:39:04 GMT",
"version": "v2"
},
{
"created": "Wed, 15 Aug 2018 02:40:26 GMT",
"version": "v3"
}
] | 2018-09-12 | [
[
"Liu",
"Mengyun",
""
],
[
"Ma",
"Bo-Qiang",
""
]
] | We study the helicity distributions of light flavor quark-antiquark ($q \bar{q}$) pairs in the nucleon sea. The valence quarks are handled by adopting the light-cone SU(6) quark-spectator-diquark model and the sea $q \bar{q}$ pairs are treated from statistical consideration by introducing the helicity suppression factors $l_q(x)$ and $\bar l_q(x)$ to parametrize the helicity distributions of q-flavor sea quark and antiquark respectively, while $\Delta l_q(x)=l_q(x)-\bar l_q(x)$ represents a combined effect of helicity contribution due to sea $q \bar{q}$ pairs. From fitting the nucleon polarization asymmetries $A^N_1$ in inclusive deep inelastic scattering processes and the single-spin asymmetries $A^{W^{\pm}}_L$ in Drell-Yan type processes, we find a significant asymmetry between the quark and antiquark helicity distributions of the nucleon sea. Therefore the quark-antiquark asymmetry of helicity distributions of nucleon sea $q \bar{q}$ pairs, i.e., $\Delta q_s(x) \neq \Delta \bar q_s(x)$, plays an important role for a comprehensive understanding of the nucleon spin content. |
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