  Neutron stars are formed in core-collapse supernova explosions, where a large
number of neutrinos are emitted. In this paper, supernova neutrino light curves
are computed for the cooling phase of protoneutron stars, which lasts a few
minutes. In the numerical simulations, 90 models of the phenomenological
equation of state with different incompressibilities, symmetry energies, and
nucleon effective masses are employed for a comprehensive study. It is found
that the cooling timescale is longer for a model with a larger neutron star
mass and a smaller neutron star radius. Furthermore, a theoretical expression
of the cooling timescale is presented as a function of the mass and radius and
it is found to describe the numerical results faithfully. These findings
suggest that diagnosing the mass and radius of a newly formed neutron star
using its neutrino signal is possible.
