Rates for nucleation of two-flavor quark matter in a neutron star core, originally composed of nuclear matter in β equilibrium, are calculated at zero temperature by a quantum tunneling analysis incorporating the electrostatic energy. We find that a nucleated droplet would develop into bulk matter due to electron screening effects. ∗) E-mail address: [email protected] ∗∗) E-mail...

In nuclear collisions induced by stable or radioactive neutron-rich nuclei a transient state of nuclear matter with an appreciable isospin asymmetry as well as thermal and compressional excitation can be created. This offers the possibility to study the properties of nuclear matter in the region between symmetric nuclear matter and pure neutron matter. In this review, we discuss recent theoreti...

φ-meson mass in nuclear matter (m∗φ) is investigated using an effective Lagrangian of φ interacting with octet baryons. m∗φ decreases by a few % in nuclear matter due to the current conservation and effective nucleon/hyperon masses. Its implication to the p-A and A-A collisions are briefly discussed. Submitted to Prog. Theor. Phys.

Medium modifications of the πωρ vertex are analyzed in context of the ω → πγ and ρ → πγ decays in nuclear matter. A relativistic hadronic model with mesons, nucleons, and ∆(1232) isobars is applied. A substantial increase of the widths for the decays ω → πγ and ρ → πγ is found for photon virtualities in the range 0.3 − 0.6GeV. This enhancement has a direct importance for the description of dile...

We investigate the properties of 3He, 4He, 6He, 7Li and 16O nuclei in nuclear matter of finite temperature and density. A Dyson expansion of the many-body Green function leads to few-body equations that are solved using the Integro-Differential Equation Approach (IDEA) and the Antisymmetrized Molecular Dynamics (AMD) methods. The use of the latter method allows us to trace the individual moveme...

As an alternative approach to the infinite-array description of dense matter in the Skyrme model, we report about the properties of a single skyrmion on a compact 3-sphere of finite radius. The density of this matter can be increased by decreasing the hypersphere radius. As in the array calculations one encounters a transition to a distinct high density phase characterized by a delocalization i...

Neutrino-matter cross sections and interaction rates are central to the core-collapse supernova phenomenon and, very likely, to the viability of the explosion mechanism itself. In this paper, we describe the major neutrino scattering, absorption, and production processes that together influence the outcome of core collapse and the cooling of protoneutron stars. One focus is on energy redistribu...

We investigate deuteron formation in nuclear matter at finite temperatures within a systematic quantum statistical approach. We consider formation through three-body collisions relevant already at rather moderate densities because of the strong correlations. The three-body in-medium reaction rates driven by the break-up cross section are calculated using exact three-body equations (Alt-Grassber...

Computer simulations are used to find the trajectories of nuclear reactions in the liquidgas phase transition regime. It is found that proton induced and heavy ion induced reactions at intermediate energies enter the liquidgas transition region, albeit in different ways. Effects arising from the mechanical instability of nuclear matter are seen in the simulations, although it has not yet been d...