6699997
THERMAL RELAXATION TIME IN CHEMICALLY NON-EQUILIBRATED QUARK-GLUON PLASMA
The definition of thermal relaxation time is extended to chemically non-equilibrated quark-gluon plasma and the chemical non-equilibrated thermal relaxation times for partons are calculated using the non-equilibrium Debye mass as the infrared regulator. The dependence of the thermal relaxation time on the fugacity is given and the influence of the chemical non-equilibration is discussed. We find that there are threshold fugacities lambda(g)* and lambda(q)* for gluons and quarks. for lambda(g) lambda(g)*(lambda(q) > lambda(q)*), ratios are almost 1. It is shown that there is also the two-stage equilibration in a chemically non-equilibrated plasma. We also discussed the effect of using the non-equilibrium Debye mass as the infrared cutoff. (C) 1998 Published by Elsevier Science B.V.
123725926
Quark propagator with a quark mass term in the color-superconducting phase
119827604
A model for the peripheral process in ultrarelativistic nucleus-nucleus collisions
A model for the peripheral process in ultrarelativistic nucleus-nucleus collisions is proposed to explain the first experimental results of interactions of oxygen nuclei in nuclear emulsions at the highest energy now available. The fraction of the interactions producing `white' stars and the mean value of NH for different incident energies and colliding nuclei are given.
123880856
Phase-space quark counting rule
SummaryA simple quark counting rule based on the phase-space consideration suggested before is used to fit all 39 recent experimental data points on inclusive reactions. Parameter-free relations are found to agree with experiments. Excellent detail fits are obtained for 11 inclusive reactions.RiassuntoSi usa una semplice regola per contare i quark basata sull'uso dello spazio delle fasi suggerita prima per adattare 39 recenti punti sperimentali sulle reazioni inclusive. Si trova che le relazioni senza parametri sono in accordo con gli esperimenti. Si ottengono eccellenti adattamenti dei dettagli per 11 reazioni inclusive.РезюмеРанее предложенное простое правило вычисления кварков, основанное на рассмотрении фазового пространства, применяется для подгонки всех 39 недавних экспериментальных точек в инклюзивных реакциях. Определяются соотношения без параметров. Для 11 инклюзивных реакций получается хорошее согласие с экспериментами.
119992531
Correlation between transverse energy and zero-degree energy in relativistic heavy-ion collisions
Based on the participant-spectator picture, applying the multisource model, the distributions of the zero-degree energy (EZD) and the transverse energy (ET) in the projectile-fragmentation region in relativistic heavy-ion collisions are calculated. The correlation between ET and EZD distributions is also analyzed. For collisions of 60A and 200A GeV 16O with different targets our results fit the new data of WA80 at CERN very well.
14601338
The mesonic fluctuations and corrections in the chiral symmetry breaking vacuum
Abstract The mesonic quantum fluctuations and their corrections on the chiral condensate and pion polarization function are investigated in the self-consistent scheme of SU(2) Nambu–Jona-Lasinio model by exactly calculating the next-to-leading order (NLO) Feynman diagrams in 1/ N c expansion. While the fluctuations and corrections depend strongly on the meson's three-momentum cut-off Λ M , no chiral symmetry restoration is found since the cancellation between the NLO and the one-quark-loop diagram with quark mass deviated from the mean-field value.
118506210
Testing the realistic seesaw model with two heavy Majorana neutrinos at the CERN Large Hadron Collider
In the conventional type-(I+II) seesaw model, the effective mass matrix of three known light neutrinos is given by M(v) = M(L) - M(D)M(R)(-1)M(D)(T) in the leading-order approximation. We propose an intriguing scenario, in which the structural cancellation condition M(D)M(R)(-1)M(D)(T) = 0 is guaranteed by the A(4) x Z(2) flavor symmetry. As a consequence, neutrino masses are mainly generated by the Higgs triplet M(v) = M(L), while the neutrino mixing matrix is non-unitary and takes on the nearly tri-bimaximal pattern. A discriminating feature of this scenario from the pure type-II seesaw model is that the lepton-number-violating signatures induced by the heavy Majorana neutrinos can be discovered at the CERN Large Hadron Collider. We calculate the total cross section of the same-sign dilepton events pp -> l(alpha)(+/-)N(i) -> l(alpha)(+/-)l(beta)(+/-)jj (for i = 1, 2 and alpha, beta = e, mu, tau), and emphasize the significant interference of the contributions from two different heavy Majorana neutrinos. The background from the standard model and the kinematic cuts used to reduce it have been considered. The possible way to distinguish between the signals from heavy Majorana neutrinos and those from doubly-charged Higgs bosons is briefly discussed. (C) 2009 Elsevier B.V. All rights reserved.
117946473
Black-hole creation in quantum cosmology
— It is proven that the probability of a black hole created from the de Sitter space-time background, at the WKB level, is the exponential of one quarter of the sum of the black hole and cosmological horizon areas, or the total entropy of the universe. This is true not only for the spherically symmetric cases of the Schwarzschild or Reissner-Nordstrom black holes, but also for the rotating case of the Kerr black hole and the rotating charged case of the Newman black hole. The de Sitter metric is the most probable evolution at the Planckian era of the universe.
124312353
The Hierarchy Problem and Lifshitz Type Quantum Field Theory
We study the Lifshitz type extension of the standard model (SM) at UV, with dynamical critical exponent z=3. One loop radiative corrections to the Higgs mass in such a model is calculated. Our result shows that, the Hierarchy problem, which has initiated many excellent extension of the minimal SM, can be weakened in the z=3 Lifshitz type quantum field theory.
2474648
Neutrino masses and lepton-flavor-violating τ decays in the supersymmetric left-right model
In the supersymmetric left-right model, the light neutrino masses are given by the Type-II seesaw mechanism. A duality property of this mechanism indicates that there exist eight possible Higgs triplet Yukawa couplings which result in the same neutrino mass matrix. In this paper, we work out the one-loop renormalization group equations for the effective neutrino mass matrix in the supersymmetric left-right model. The stability of the Type-II seesaw scenario is briefly discussed. We also study the lepton-flavor-violating processes (tau -> mu gamma and tau -> e gamma) by using the reconstructed Higgs triplet Yukawa couplings.
118662547
Compromise between neutrino masses and collider signatures in the type-II seesaw model
A natural extension of the standard $\mathrm{SU}(2{)}_{\mathrm{L}}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}_{\mathrm{Y}}$ gauge model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a $6\ifmmode\times\else\texttimes\fi{}6$ neutrino mass matrix which contains three $3\ifmmode\times\else\texttimes\fi{}3$ submatrices, ${M}_{\mathrm{L}}$, ${M}_{\mathrm{D}}$ and ${M}_{\mathrm{R}}$. We show that three light Majorana neutrinos (i.e., the mass eigenstates of ${\ensuremath{\nu}}_{e}$, ${\ensuremath{\nu}}_{\ensuremath{\mu}}$, and ${\ensuremath{\nu}}_{\ensuremath{\tau}}$) are exactly massless in this model, if and only if ${M}_{\mathrm{L}}={M}_{\mathrm{D}}{M}_{\mathrm{R}}^{\ensuremath{-}1}{M}_{\mathrm{D}}^{T}$ exactly holds. This no-go theorem implies that small but nonvanishing neutrino masses may result from a significant but incomplete cancellation between ${M}_{\mathrm{L}}$ and ${M}_{\mathrm{D}}{M}_{\mathrm{R}}^{\ensuremath{-}1}{M}_{\mathrm{D}}^{T}$ terms in the Type-II seesaw formula, provided three right-handed Majorana neutrinos are of $\mathcal{O}(1)\text{ }\text{ }\mathrm{TeV}$ and experimentally detectable at the LHC. We propose three simple Type-II seesaw scenarios with the ${A}_{4}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}_{\mathrm{X}}$ flavor symmetry and its explicit breaking to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the $3\ifmmode\times\else\texttimes\fi{}3$ neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.