Hot hypernuclear matter in the modified quark-meson coupling model

Abstract

Hot hypernuclear matter is investigated in an explicit SU͑3͒ quark model based on a mean-field description of nonoverlapping baryon bags bound by the self-consistent exchange of scalar , and vector , mesons. The , mean fields are assumed to couple to the u,d quarks while the , mean fields are coupled to the s quark. The coupling constants of the mean fields with the quarks are assumed to satisfy SU͑6͒ symmetry. The calculations take into account the medium dependence of the bag parameter on the scalar fields ,. We consider only the octet baryons N,⌳,⌺,⌶ in hypernuclear matter. An ideal gas of the strange mesons K and K* is introduced to keep zero the net strangeness density. Our results for symmetric hypernuclear matter show that a phase transition takes place at a critical temperature around 160Ϯ10 MeV in which the scalar mean fields , take nonzero values at zero baryon density. Furthermore, the bag parameters of the baryons decrease significantly at and above this critical temperature, indicating the onset of quark deconfinement. The present results imply that the onset of quark deconfinement in SU͑3͒ hypernuclear matter is much stronger than in SU͑2͒ nuclear matter.

Nucleon and hadron structure changes in the nuclear medium and the impact on observables

“…The dilaton potential improves the shape of the saturation curve at T = 0 and significantly affects the properties of hot nuclear matter. Hot hypernuclear matter [101], neutron stars [102] and relativistic heavy iron reactions [103] have also been investigated in their approach. 16 O, 40 Ca, 48 Ca, 90 Zr, 208…”

ϕ meson mass and decay width in strange hadronic matter

“…ζ is a strange scalar-isoscalar field identified with the scalar meson with strange quark content ss [85] and plays an important role in strange matter. Further, the scalar-isovector field δ is introduced in the relativistic mean-field models to study the properties of isospin asymmetric matter.…”

“…This field is identified with the meson having quark content ∼(ūu-dd). The ζ and δ mesons are generally identified with mass around 980 MeV [85][86][87]. The nucleons and hyperons in the medium interact through the exchange of the scalar fields σ , ζ , and δ along with the vector fields ω, ρ, and φ.…”

Thermal kaon production in relativistic heavy-ion collisions

“…The density-dependence of the bag parameter is introduced by coupling it to the scalar mesonic field [2,4]. We have used the MQMC to study the properties of nuclear matter and quark deconfinement at finite temperature [5,6,7] and the phase transition from the hadronic phase to the quark-gluon plasma [7,8]. We have also studied the properties of neutron stars in the context of MQMC [9].…”