Friday, February 3, 2012

1202.0143 (Nobutoshi Yasutake et al.)

Amorphous state in the mixed phase of quark-hadron phase transition in
protoneutron stars
   [PDF]

Nobutoshi Yasutake, Toshiki Maruyama, Toshitaka Tatsumi
We study the quark-hadron 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 there appears no crystalline ("pasta") structure 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. The local
charge neutrality is approximately attained there. After neutrinos are ejected,
the matter becomes a binary system. Charge neutrality is globally ensured and
the pasta structures appear there. These features are important to consider the
quark-hadron phase transition during the evolution of protoneutron stars.
View original: http://arxiv.org/abs/1202.0143

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