32394428
Thermodynamical fluctuations of meson fields for a quantum hadrodynamics model.
Using the real-time Green's-function method with a pair-cutoff approximation up to second order, the thermodynamical fluctuation effects of meson fields on the QHD-II model are studied. We find that the fluctuation effects of meson fields, in particular, the \ensuremath{\pi} meson field, on saturation energy, effective mass of nucleon, and pressure are remarkable in the low-density region and/or high-temperature region. The results given by the QHD-I and QHD-II models are compared. The value of the critical point of the liquid-gas phase transition for the QHD-II model is given.
121435769
Phase Structure of Strange Matter in a Non-topological Soliton Model
A non-topological soliton model with strange quarks is suggested to investigate the phase structure of strange matter. The results are qualitatively in agreement with that obtained by MIT bag model provided the ratio of coupling constants of different quarks to soliton scalar field chi(sigma) = g(s sigma)/g(q sigma) larger than a critical value chi(c) similar to 0.86, but as chi(sigma) gets smaller than chi(c), the phase structure may change.
124938750
The effects of vacuum fluctuations on ρ meson masses in hot and dense matter
Based on the thermo field dynamics, the temperature- and density-dependent effective mass and screening mass of ρ meson in the vector–tensor ρ–meson–nucleon–nucleon coupling model have been calculated. The effects of the vacuum fluctuation corrections through the effective nucleon mass are examined. We have shown that the vacuum fluctuation gives an important correction to the self-energy of ρ meson and leads to a reduction of ρ-meson mass in hot and dense matter.
121746713
The effective mass and screening mass of the rho meson for the vector dominance model and the vector coupling model at finite temperature and density
In the framework of thermo-field dynamics, the temperature and/or density dependences of the effective mass and the screening mass of the rho -meson for the vector dominance model and the nucleon-nucleon- rho -meson (NN rho ) vector coupling model have been calculated. We have found that for the vector dominance model, the effective mass and the screening mass of the rho -meson increase with temperature, and for the NN rho vector coupling model, they remain almost unchanged with temperature, but increase with density.
120297881
Thermodynamical fluctuations of meson fields for the Zimanyi-Moszkowski model
By using the real-time Green{close_quote}s function method with a pair cutoff approximation up to the second order, the thermodynamical fluctuation effects of meson fields on the Zimanyi-Moszkowski model are investigated. We find that in the fluctuation effects on the effective mass of the nucleon, the pressures are considerable in the low-baryon-density region and/or the high-temperature regions. The results of the Zimanyi-Moszkowski model and the Welecka model beyond the mean-field approximation are compared. {copyright} {ital 1997} {ital The American Physical Society}
1003631
Masses of hadrons and nucleon-nucleon interaction at finite temperature and density in a quantum hadrodynamics model.
The effective masses and the screening masses of hadrons at finite temperature and density for the quantum hadrodynamics two (QHD-II) model have been investigated under the one-loop approximation. The nucleon-nucleon interaction through pion, sigma, omega, and rho mesons exchange in hot nuclear matter is given. We have found that the potential well of the nucleon-nucleon interaction becomes shallow as the temperature and/or density increases. At a critical temperature and/or a critical density, the potential well disappears.
41901069
Geometrical interpretation of SO(7): A critical dynamical symmetry.
Potential-energy surfaces are obtained for the three dynamical-symmetry chains of SO(8) within the fermion-dynamical-symmetry model. A remarkable feature is that the SO(7) dynamical symmetry is transitional and ..beta.. soft. The transitional or ''critical'' behavior of SO(7) is vividly demonstrated.
858386
Chiral symmetry, quark mass, and scaling of the overlap fermions
The chiral symmetry relation and scaling of the overlap fermions are studied numerically on the quenched lattices at 3 couplings with about the same physical volume. We find that the generalized Gell-Mann-Oakes-Renner relation is satisfied to better than 1% down to the smallest quark mass at m(0)a = 0.006. We also obtain the quark mass from the PCAC relation and the pseudoscalar masses. The renormalization group invariant quark mass is shown to be fairly independent of scale. The pi and rho masses at a fixed m(pi)/m(rho) ratio indicate small O(a(2)) corrections. It is found that the critical slowing down sets in abruptly at a very small quark mass close to those of the physical u and d quarks.
6589068
Top quark as a topological color soliton.
In this paper I propose a scenario for the top quark as a topological color soliton. I illustrate some features of the top quark as a soliton in a toy model based on a nonlinear realization of SU{sub {ital L}}(3){times}SU{sub {ital R}}(3)/SU{sub {ital L}+{ital R}}(3) with SU{sub {ital L}+{ital R}}(3) being the color gauge group.
32391471
Gluon propagator and transverse vertices.
It is shown explicitly that in the axial gauge the Slavnov-Taylor identity contains no useful information for determining the gluon propagator through the Dyson-Schwinger equation; rather, it is the transverse vertex which plays the crucial role.
38317170
New tripreon models with semisimple metacolor groups.
A systematic analysis of the /ital chiral/ tripreon models with SU(/ital N/)/times/SO(/ital M/)-metacolor symmetry is made. Unique solutions to the 't Hooft anomaly-matching condition with the Bars constraint are obtained for SU(3)/times/SO(5) models which also satisfy complementarity. Both the metacolor group and the gauged color-flavor subgroup of the metaflavor group are asymptotically free. A model which has a low-metacolor-energy scale and three generations of composite fermions with the quantum numbers of quarks and leptons of the standard model is obtained.