  Within the framework of the improved quantum molecular dynamics model, the
medium modifications on the free nucleon-nucleon elastic cross sections are
investigated. By using various in-medium nucleon-nucleon elastic cross sections
in the model, the nucleon-induced reactions on various targets are simulated,
and the excitation functions of reaction cross sections in the energy range
from 25 MeV to 1 GeV are calculated. By comparing the calculations with the
experimental data, an isospin, density, and momentum-dependence medium
correction factor on free nucleon-nucleon elastic cross sections is determined.
