11,248 research outputs found
Neutron Stars with Bose-Einstein Condensation of Antikaons as MIT Bags
We investigate the properties of an antikaon in medium, regarding itas a MIT
bag. We first construct the MIT bag model for a kaon with and
in order to describe the interaction of-quarks in hyperonic matter in the
framework of the modifiedquark-meson coupling model. The coupling constant
in the density-dependent bag constant is treated
as afree parameter to reproduce the optical potential of a kaon in asymmetric
matter and all other couplings are determined by usingSU(6) symmetry and the
quark counting rule. With various values ofthe kaon potential, we calculate the
effective mass of a kaon inmedium to compare it with that of a point-like kaon.
We thencalculate the population of octet baryons, leptons and and
theequation of state for neutron star matter. The results show thatkaon
condensation in hyperonic matter is sensitive to the -quarkinteraction and
also to the way of treating the kaon. The mass andthe radius of a neutron star
are obtained by solving theTolmann-Oppenheimer-Volkoff equation.Comment: 14 figure
From orbifolding conformal field theories to gauging topological phases
Topological phases of matter in (2+1) dimensions are commonly equipped with
global symmetries, such as electric-magnetic duality in gauge theories and
bilayer symmetry in fractional quantum Hall states. Gauging these symmetries
into local dynamical ones is one way of obtaining exotic phases from
conventional systems. We study this using the bulk-boundary correspondence and
applying the orbifold construction to the (1+1) dimensional edge described by a
conformal field theory (CFT). Our procedure puts twisted boundary conditions
into the partition function, and predicts the fusion, spin and braiding
behavior of anyonic excitations after gauging. We demonstrate this for the
electric-magnetic self-dual gauge theory, the twofold symmetric
, and the -symmetric Wess-Zumino-Witten theories.Comment: 23 pages, 1 figur
Effective response theory for zero energy Majorana bound states in three spatial dimensions
We propose a gravitational response theory for point defects (hedgehogs)
binding Majorana zero modes in (3+1)-dimensional superconductors. Starting in
4+1 dimensions, where the point defect is extended into a line, a coupling of
the bulk defect texture with the gravitational field is introduced.
Diffeomorphism invariance then leads to an Kac-Moody current running
along the defect line. The Kac-Moody algebra accounts for the
non-Abelian nature of the zero modes in 3+1 dimensions. It is then shown to
also encode the angular momentum density which permeates throughout the bulk
between hedgehog-anti-hedgehog pairs.Comment: 7 pages, 3 figure
Medium effects of magnetic moments of baryons on neutron stars under strong magnetic fields
We investigate medium effects due to density-dependent magnetic moments of
baryons on neutron stars under strong magnetic fields. If we allow the
variation of anomalous magnetic moments (AMMs) of baryons in dense matter under
strong magnetic fields, AMMs of nucleons are enhanced to be larger than those
of hyperons. The enhancement naturally affects the chemical potentials of
baryons to be large and leads to the increase of a proton fraction.
Consequently, it causes the suppression of hyperons, resulting in the stiffness
of the equation of state. Under the presumed strong magnetic fields, we
evaluate relevant particles' population, the equation of state and the maximum
masses of neutron stars by including density-dependent AMMs and compare them
with those obtained from AMMs in free space
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