Nuclear matter

About: Nuclear matter is a research topic. Over the lifetime, 10180 publications have been published within this topic receiving 248261 citations.

Temperature and free-nucleon densities of nuclear matter exploding into light clusters in heavy-ion collisions

Abstract: A new statistical approach is adopted which, through a suitable analysis of light clusters emitted in heavy-ion collisions, allows us to evaluate temperature and free-nucleon densities of the emission source. All known data concerning the emission of2H,3H,3He,4He measured in a common experiment are used. These data refer to 19 heavy-ion reactions studied at projectile energies between 26 and 2100 MeV per nucleon. Analysed events are only those attributable to the equilibrium component through carefully adopted selections. Among the results, a correlation is observed between temperatureT and total free-nucleon density ϱt F of the emission source. A nuclear-matter model is formulated in order to compare its quantitative predictions with the observed (T, ϱ t F) correlation. A good agreement is found by this comparison.

Hadron-quark phase transition in dense matter and neutron stars

Abstract: We study the hadron-quark phase transition in the interior of neutron stars (NS's). We calculate the equation of state (EOS) of hadronic matter using the Brueckner-Bethe-Goldstone formalism with realistic two-body and three-body forces, as well as a relativistic mean field model. For quark matter we employ the MIT bag model constraining the bag constant by using the indications coming from the recent experimental results obtained at the CERN SPS on the formation of a quark-gluon plasma. We find it necessary to introduce a density-dependent bag parameter and the corresponding consistent thermodynamical formalism. We calculate the structure of NS interiors with the EOS comprising both phases, and we find that the NS maximum masses fall in a relatively narrow interval, $1.4{M}_{\ensuremath{\bigodot}}l~{M}_{\mathrm{max}}l~{1.7M}_{\ensuremath{\bigodot}}.$ The precise value of the maximum mass turns out to be only weakly correlated with the value of the energy density at the assumed transition point in nearly symmetric nuclear matter.

Linear $\sigma$ Model With Parity Doubling

Abstract: Recent lattice-gauge-theory simulations at finite temperatures have suggested that chiral-symmetry restoration at finite temperatures entails parity doubling of the baryon spectrum. We show that a natural extension of the Gell-Mann--L\'evy model incorporates this effect. Predictions of this candidate effective model for the hadronic component of high-density and high-temperature nuclear matter are discussed. The model suggests a parametrization of the dependence of the baryon-doublet masses on the quark mass. This parametrization is compared with the recent lattice results.