Narrow Results

We report on results about the mass sensitivity of chiral symmetry restoration in the linear sigma model. For masses of the pseudoscalar meson octet which are close to the experimental values, we observed only a gradual change in the order parameters, when the temperature was changed. To estimate the size of the first order transition region around the chiral limit, we have varied the mass input for the tree level parametrization in several ways. The point with realistic meson masses turned out to lie well inside the crossover region.

Total reaction cross sections for 50 and 100 MeV protons have been calculated for several nuclei using Gambhir–Patil semi-phenomenological nucleon density in the Coulomb modified Glauber model. It is shown that the semi-phenomenological nucleon density distribution provides quite satisfactory description of the observed A-dependence of the proton reaction cross sections.

In this work we study the effect of the Coulomb energy shift on proton total reaction cross-section (σ_R) at 25, 50, and 100 MeV for several nuclei in the mass region 12≤A≤208. The cross-sections are computed using the Coulomb modified Glauber model in the optical limit approximation, and the semi-phenomenological proton and neutron density distributions. We find that the Coulomb energy shift has a significant effect on the calculated σ_R, and that it brings the theory quite close to the experiment.