119328473
QCD phase transition in rotating neutron star, neutrino beaming and gamma-ray bursters
We have studied the emission of neutrinos from a rotating hybrid star. We find that the emission is predominantly confined to a very small angle, provided the core of the star is in a mixed phase of quarks and hadrons and the size of such a mixed phase is small. Annihilation of neutrinos to produce gamma rays has been discussed. The estimated duration of the burst is found to be within the observational range.
119596515
General relativistic effects on the conversion of nuclear to two-flavor quark matter in compact stars
We investigate the general relativistic (GR) effects on the conversion from nuclear to two-flavor quark matter in compact stars, both static as well as rotating. We find that GR effects lead to qualitative differences in rotating stars, indicating the inadequacy of nonrelativistic or even special relativistic treatments for these cases.
119116708
Fluctuations and correlations of conserved charges in an excluded-volume hadron resonance gas model
We present temperature ($T$) and baryonic chemical potential ($\mu_B$) dependence of higher order fluctuations and correlation between conserved charges in Excluded Volume Hadron Resonance Gas (EVHRG) model. Products of moments, such as ratio of variance to mean ($\sigma^2/M)$, product of skewness and standard deviation ($S\sigma$), product of kurtosis and variance ($\kappa\sigma^2$), for net-proton, net-kaon and net-charge have been evaluated on the phenomenologically determined freeze-out curve. Further, products of moments for net-proton and net-charge have been compared with the experimental data measured by STAR experiment. The dependence of the model result on the hadronic radius parameter has also been discussed.
118883030
Effect of in-medium meson masses on nuclear matter properties
Masses of hadrons (baryons as well as mesons) are modified in the nuclear medium because of their interactions. In this paper we investigate the effect of in-medium meson masses on the properties of the nuclear matter. The calculations are performed in the Walecka model. We find that with the inclusion of meson mass modification, the computed equation of state becomes softer. We also find that the decrease in the nucleon as well as meson masses in the medium is smaller than that obtained in the case when the in-medium meson masses are not taken into account.
119265408
STRANGE BARYONS, NUCLEAR DRIPLINE AND SHRINKAGE: A RELATIVISTIC MEAN FIELD STUDY
Neutron and proton driplines of single-Λ and double-Λ hypernuclei, Ξ- hypernuclei as well as normal nuclei are studied within a relativistic mean field approach using an extended form of the FSU Gold Lagrangian density. Hyperons are found to produce bound nuclei beyond the normal nuclear driplines. Radii are found to decrease in hypernuclei near the driplines, in line with observations in light Λ hypernuclei near the stability valley. The inclusion of a Ξ- introduces a much larger change in radii than one or more Λ's.
6848119
Relics of cosmic quark-hadron phase transition and massive compact halo objects
Abstract We propose that the cold dark matter (CDM) is composed entirely of quark matter, arising from a cosmic quark-hadron transition. We show that compact gravitational objects, with masses around 0.5 M ⊙ , could have evolved out of the such CDM.
41364893
On entanglement entropy functionals in higher-derivative gravity theories
A bstractIn arXiv:1310.5713 [1] and arXiv:1310.6659 [2] a formula was proposed as the entanglement entropy functional for a general higher-derivative theory of gravity, whose lagrangian consists of terms containing contractions of the Riemann tensor. In this paper, we carry out some tests of this proposal. First, we find the surface equation of motion for general four-derivative gravity theory by minimizing the holographic entanglement entropy functional resulting from this proposed formula. Then we calculate the surface equation for the same theory using the generalized gravitational entropy method of arXiv:1304.4926 [3]. We find that the two do not match in their entirety. We also construct the holographic entropy functional for quasi-topological gravity, which is a six-derivative gravity theory. We find that this functional gives the correct universal terms. However, as in the R2 case, the generalized gravitational entropy method applied to this theory does not give exactly the surface equation of motion coming from minimizing the entropy functional.