  We argue that significant probability of protons with momenta above their
Fermi surface leads for proton concentrations p/n > 1/8 to the enhancement of
termally excited direct and modified URCA processes within a cold neutron star,
and to a nonzero probability of direct URCA processes for small proton
concentrations (p/n < 1/8). We evaluate high momentum tails of neutron, proton
and electrons distributions within a neutron star. We expect also significantly
faster neutrino cooling of hyperon stars.
