Speaker: C. J. Horowitz (Indiana University, Bloomington)

Nuclear Pasta and Neutrino Interactions in Supernovae

All conventional matter is "frustrated". It is correlated at short distances from attractive strong interactions and anti correlated at large distances because of Coulomb repulsion. Often these length scales are well separated so nucleons bind into nuclei that are segregated on a crystal lattice. However at great densities, the length scales become comparable and matter should cluster into complex structures called nuclear pasta. Pasta may involve spherical (meat ball), slab like (lasagna) , and/or rod like (spaghetti) shapes. These phases are expected in the inner crust of neutron stars and in core-collapse supernovae. The dynamics of core-collapse supernovae is very sensitive to the interactions between neutrinos and nucleons/nuclei. Indeed, neutrino excitation of the low-energy modes of the pasta may allow for a significant energy transfer to the nuclear medium, thereby energizing the stalled supernovae shock. The linear response of the nuclear pasta to neutrinos is modeled via a simple semi-classical simulation. The transport mean-free path for $\mu$ and $\tau$ neutrinos is expressed in terms of the static structure factor of the pasta, which is evaluated using Metropolis Monte Carlo and molecular dynamics simulations.