88,647 research outputs found
Nuclear Three-body Force Effect on a Kaon Condensate in Neutron Star Matter
We explore the effects of a microscopic nuclear three-body force on the
threshold baryon density for kaon condensation in chemical equilibrium neutron
star matter and on the composition of the kaon condensed phase in the framework
of the Brueckner-Hartree-Fock approach. Our results show that the nuclear
three-body force affects strongly the high-density behavior of nuclear symmetry
energy and consequently reduces considerably the critical density for kaon
condensation provided that the proton strangeness content is not very large.
The dependence of the threshold density on the symmetry energy becomes weaker
as the proton strangeness content increases. The kaon condensed phase of
neutron star matter turns out to be proton-rich instead of neutron-rich. The
three-body force has an important influence on the composition of the kaon
condensed phase. Inclusion of the three-body force contribution in the nuclear
symmetry energy results in a significant reduction of the proton and kaon
fractions in the kaon condensed phase which is more proton-rich in the case of
no three-body force. Our results are compared to other theoretical predictions
by adopting different models for the nuclear symmetry energy. The possible
implications of our results for the neutron star structure are also briefly
discussed.Comment: 15 pages, 5 figure
Bulk Matter and the Boundary Quantum Null Energy Condition
We investigate the quantum null energy condition (QNEC) in holographic CFTs,
focusing on half-spaces and particular classes of states. We present direct,
and in certain cases nonperturbative, calculations for both the diagonal and
off- diagonal variational derivatives of entanglement entropy. In d > 2, we
find that the QNEC is saturated. We compute relations between the off-diagonal
variation of entanglement, boundary relative entropy, and the bulk stress
tensor. Strong subadditivity then leads to energy conditions in the bulk. In d
= 2, we find that the QNEC is in general not saturated when the Ryu-Takayanagi
surface intersects bulk matter. Moreover, when bulk matter is present the QNEC
can imply new bulk energy conditions. For a simple class of states, we derive
an example that is stronger than the bulk averaged null energy condition and
reduces to it in certain limits.Comment: 22 page
Heavy Quarkonium Production at LHC through Boson Decays
The production of the heavy -quarkonium, -quarkonium
and -quarkonium states (-quarkonium for short), via
the semi-inclusive decays, has been systematically studied within the
framework of the non-relativistic QCD. In addition to the two color-singlet
-wave states, we also discuss the production of the four color-singlet
-wave states and (with ) together with the two color-octet components
and . Improved
trace technology is adopted to derive the simplified analytic expressions at
the amplitude level, which shall be useful for dealing with the following
cascade decay channels. At the LHC with the luminosity and the center-of-mass energy TeV, sizable
heavy-quarkonium events can be produced through the boson decays, i.e.
, and
-wave charmonium events per year can be obtained; and
, and -wave
-quarkonium events per year can be obtained. Main theoretical
uncertainties have also been discussed. By adding the uncertainties caused by
the quark masses in quadrature, we obtain KeV, KeV, KeV and eV.Comment: 24 pages, 12 figures. References updated. To be published in
Phys.Rev. D. To match the published versio
Microscopic three-body forces and kaon condensation in cold neutrino-trapped matter
We investigate the composition and the equation of state of the kaon
condensed phase in neutrino-free and neutrino-trapped star matter within the
framework of the Brueckner-Hartree-Fock approach with three-body forces. We
find that neutrino trapping shifts the onset density of kaon condensation to a
larger baryon density, and reduces considerably the kaon abundance. As a
consequence, when kaons are allowed, the equation of state of neutrino-trapped
star matter becomes stiffer than the one of neutrino free matter. The effects
of different three-body forces are compared and discussed. Neutrino trapping
turns out to weaken the role played by the symmetry energy in determining the
composition of stellar matter, and thus reduces the difference between the
results obtained by using different three-body forces.Comment: 9 pages, 7 figures, accepted in Phys. Rev.
On Fast and Robust Information Spreading in the Vertex-Congest Model
This paper initiates the study of the impact of failures on the fundamental
problem of \emph{information spreading} in the Vertex-Congest model, in which
in every round, each of the nodes sends the same -bit message
to all of its neighbors.
Our contribution to coping with failures is twofold. First, we prove that the
randomized algorithm which chooses uniformly at random the next message to
forward is slow, requiring rounds on some graphs, which we
denote by , where is the vertex-connectivity.
Second, we design a randomized algorithm that makes dynamic message choices,
with probabilities that change over the execution. We prove that for
it requires only a near-optimal number of rounds, despite a
rate of failures per round. Our technique of choosing
probabilities that change according to the execution is of independent
interest.Comment: Appears in SIROCCO 2015 conferenc
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