Neutrino Scattering in Strangeness-rich Stellar Matter Sanjay Reddy and Madappa Prakash

We calculate neutrino cross sections from neutral current reactions in dense matter containing hyperons. We show that Σ− hyperons give significant contributions. To lowest order, the contributions from the neutral Λ and Σ, which have zero hypercharge, vanish. However, their presence furnishes baryon number which decreases the relative concentrations of nucleons. This leads to significant reductions in the cross sections. Due to the uncertainty in strong interactions at high density, the neutrino opacity may vary by a factor of about 2 depending on the behavior of the effective masses. Subject headings: dense matter – stars: neutron – stars: opacities – stars: neutrinos