430 research outputs found
Role of magnetic interactions in neutron stars
In this work, we present a calculation of the non-Fermi liquid correction to
the specific heat of magnetized degenerate quark matter present at the core of
the neutron star. The role of non-Fermi liquid corrections to the neutrino
emissivity has been calculated beyond leading order. We extend our result to
the evaluation of the pulsar kick velocity and cooling of the star due to such
anomalous corrections and present a comparison with the simple Fermi liquid
case.Comment: 6 pages, Proceedings of the 3rd International Conference on New
Frontiers in Physics, Kolymbari, Crete, Greece (matches published version
Radiative energy loss in an anisotropic Quark-Gluon-Plasma
We calculate radiative energy loss of heavy and light quarks in anisotropic
medium (static) in first order opacity expansion. Such an anisotropy can result
from the initial rapid longitudinal expansion of the matter, created in
relativistic heavy ion collisions. Significant dependency of the energy loss on
the anisotropy parameter () and the direction of propagation of the
partons with respect to the anisotropy axis is found. It is shown that the
introduction of early time momentum-space anisotropy can enhance the fractional
energy loss in the direction of the anisotropy, whereas it decreases when the
parton propagates perpendicular to the direction of the anisotropy.Comment: text and figures modifie
Photons from anisotropic Quark-Gluon-Plasma
We calculate medium photons due to Compton and annihilation processes in an
anisotropic media. The effects of time-dependent momentum-space anisotropy of
{\em Quark-Gluon-Plasma} (QGP) on the medium photon production are discussed.
Such an anisotropy can results from the initial rapid longitudinal expansion of
the matter, created in relativistic heavy ion collisions. A phenomenological
model for the time-dependence of the parton hard momentum scale,
, and anisotropy parameter, , has been used to
describe the plasma space-time evolution. We find significant dependency of
photon yield on the isotropization time (). It is shown that the
introduction of early time momentum-space anisotropy can enhance the photon
production by a factor of (in the central rapidity region) for {\em
free streaming} ({\em collisionally-broadened}) {\em interpolating} model if we
assume fixed initial condition. On the other hand, enforcing the fixed final
multiplicity significantly reduces the enhancement of medium photon production.Comment: 15 pages, 19 figures, few refs added, one new paragraph is added in
introduction, published in Physical Rev.
Next to leading order non Fermi liquid corrections to the neutrino emissivity and cooling of the neutron star
In this work we derive the expressions of the neutrino mean free path(MFP)
and emissivity with non Fermi liquid corrections up to next to leading
order(NLO) in degenerate quark matter. The calculation has been performed both
for the absorption and scattering processes. Subsequently the role of these NLO
corrections on the cooling of the neutron star has been demonstrated. The
cooling curve shows moderate enhancement compared to the leading order(LO)
non-Fermi liquid result. Although the overall correction to the MFP and
emissivity are larger compared to the free Fermi gas, the cooling behavior does
not alter significantly.Comment: 8 pages, 8 figures, references added, matches published versio
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