Hedgehog solitons are found in a chiral quark model with non-local interactions. The solitons are stable without the chiral-circle constraint for the meson fields, as was assumed in previous ...Nambu-Jona–Lasinio model with local interactions.
We show that the transverse-momentum spectra of all hadrons measured at RHIC, including the hyperons, are described very well in a thermal model assuming the simultaneous chemical and thermal ...freeze-outs. The model calculation takes into account all hadronic resonances and uses a simple parametrization of the freeze-out hypersurface.
By means of a simple rescaling, modifications of hadron masses and widths are incorporated into the thermal analysis of particle ratios in ultrarelativistic heavy-ion collisions. We find that ...moderate, up to 20%, changes of hadron masses do not spoil the quality of the fits, which remain as good as those obtained without modifications. Larger changes are not likely. The fits with the modified masses yield modified values of the optimal temperature and baryon chemical potential. In particular, with decreasing masses of all hadrons (except for pseudo-Goldstone bosons) the fitted values of the temperature and the baryon chemical potential are lowered, with the change approximately proportional to the scaling of masses. In addition, we find that the broadening of the hadron widths by less than a factor of two practically does not affect the fits.
We confront the hypothesis of chemical freeze-out in ultra-relativistic heavy-ion collisions with the hypothesis of large modifications of hadron masses in nuclear medium. We find that the ...thermal-model predictions for the ratios of particle multiplicities are sensitive to the values of in-medium hadronic masses. In particular, the
π
+/
p and
K
+/
p ratios decrease by about 30% when the masses of all hadrons (except for pseudo-Goldstone bosons) are scaled down by 30%.
Nonminimal substitution terms in electroweak currents are studied in effective chiral soliton models. It is found that the terms describing the structure of the pion lead to sizable effects in form ...factors and polarizabilities of the nucleon.
We analyze the event-by-event fluctuations of mean transverse momentum measured recently by the PHENIX and STAR Collaborations at RHIC. We argue that the observed scaling of strength of dynamical ...fluctuations with the inverse number of particles can be naturally explained by formation of multiparticle clusters.
Quark matter in a chiral chromodielectric model Broniowski, W; Cibej, M; Kutschera, M ...
Physical review. D, Particles and fields,
1990-Jan-01, 1990-1-00, 19900101, 1990-01-01, Letnik:
41, Številka:
1
Journal Article
Recenzirano
Zero- and finite-temperature quark matter is studied in a chiral chromodielectric model with quark, meson, and chromodielectric degrees of freedom. The mean-field approximation is used. Two cases are ...considered: two-flavor and three-flavor quark matter. It is found that at sufficiently low densities and temperatures the system is in a chirally broken phase, with quarks acquiring effective masses of the order of 100 MeV. At higher densities and/or temperatures a chiral phase transition occurs and the quarks become massless. A comparison with traditional nuclear physics suggests that the chirally broken phase with massive quark gas may be the ground state of matter at densities of the order of a few nuclear saturation densities.
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