Effects of in-medium NN cross section and density distribution on the reaction cross sections of Ne, Mg, and O isotopes with C12 at 1 GeV

Abstract

The nucleus-nucleus reaction cross sections of $^{18--34}\text{Ne},^{20--36}\text{Mg},^{16--24}\text{O}+^{12}\mathrm{C}$ at one GeV/u are calculated in the Glauber theory using different models of the nucleon-nucleon ($NN$) cross sections and nuclear densities. For in-medium effects, we consider the phenomenological (Ph), geometrical Pauli (GP), and modified combined (MC) models for the $NN$ reaction cross section. For the density distributions, we used the Sao Paulo (SP), Skyrme-Hartree-Fock (SHF), and the angle-averaged deformed Fermi (DF) densities. The results are compared with experiments as well as other theoretical calculations. It is found that the data can, generally, be described by using the Ph and GP models for in-medium effects with the SP density, which, on the other hand, predicted smaller radii. A satisfactory explanation of the experimental data is obtained by using more realistic densities such as SHF and DF with realistic radii, and the MC model for medium modifications, which involve the combined effect of the phase variation, higher momentum transfer components, and Pauli blocking of the $NN$ amplitude. The in-medium Ph and GP models when used with realistic densities, cannot describe the data at 1 GeV.