36 research outputs found
Asymmetric Neutrino Emission from Magnetized Proto-Neutron Star Matter including Hyperons in Relativistic Mean Field Theory
We calculate asymmetric neutrino absorption and scattering cross sections on
hot and dense magnetized neutron-star matter including hyperons in fully
relativistic mean field theory. The absorption/scattering cross sections are
suppressed/enhanced incoherently in the direction of the magnetic fielld, B.
The asymmetry is 2-4% at the matter density \rho_0 < \rho_B < 3\rho_0 and
temperature T < 40 MeV for B=2 X 10^{17} G. This asymmetry is comparable to the
effects owing to parity violation or asymmetric magnetic field topology
proposed for the origin of pulsar kicks.Comment: 9 pages, 3 figur
Amorphous state in the mixed phase of quark-hadron phase transition in protoneutron stars
We study the hadron-quark mixed phase in protoneutron stars, where neutrinos
are trapped and lepton number becomes a conserved quantity besides the baryon
number and electric charge. Considering protoneutron-star matter as a ternary
system, the Gibbs conditions are applied together with the Coulomb interaction.
We find that there no crystalline ("pasta") structure appears in the regime of
high lepton-number fraction; the size of pasta becomes very large and the
geometrical structure becomes mechanically unstable due to the charge screening
effect. Consequently the whole system is separated into two bulk regions like
an amorphous state, where the surface effect is safely neglected. There, the
local charge neutrality is approximately attained, so that the equation of
state is effectively reduced to the one for a binary system. Hence, we conclude
that there is no possibility for the density discontinuity to appear in
protoneutron-star matter, which is a specific feature in a pure system. These
features are important when considering astrophysical phenomena such as
supernova explosions or radiation of the gravitational wave from protoneutron
stars.Comment: 4 pages, 5 figure