# Neutrino mean-free path in non-uniform nuclear matter

Ubiratãn José Furtado (Universidade Federal de Santa Catarina, Brazil)

### 11h00 GANIL seminar room (105)

### a coffee will be served 15mn before

The behavior and properties of a neutrino in non-uniform dense nuclear matter, surrounded by electrons and other neutrinos are studied. The nuclear matter itself is modeled by the non-linear Walecka model, where the so-called nuclear pasta phase is described using the Thomas-Fermi approximation, solved in a Wigner-Seitz cell. We obtain the total cross-section and the mean-free path for the neutrinos, taking into account scattering and neutrino absorption. Coherent scattering was also calculated. We compare the final results for two know kinds of model parametrizations: one in which non-linear effects in the strong sector are explicitly written in the model Lagrangian and another one in which the coupling constants are density dependent. The solution for this problem is interesting for the understanding of neutrino diffusion in a newly born neutron star after a supernova explosion.