1,562 research outputs found
Meta-stable Supersymmetry Breaking in an N=1 Perturbed Seiberg-Witten Theory
In this contribution, we discuss the possibility of meta-stable supersymmetry
(SUSY) breaking vacua in a perturbed Seiberg-Witten theory with
Fayet-Iliopoulos (FI) term. We found meta-stable SUSY breaking vacua at the
degenerated dyon and monopole singular points in the moduli space at the
nonperturbative level.Comment: Submitted for the SUSY08 proceedings, 3 pages, 4 figures, references
added, minor change
Live imaging reveals the cellular events downstream of SARM1 activation
SARM1 is an inducible NA
Neutrino self-interaction and MSW effects on the supernova neutrino-process
We calculate the abundances of Li, B, Nb, Tc,
La, and Ta produced by neutrino induced reactions in a
core-collapse supernova explosion. We consider the modification by
self-interaction (-SI) near the neutrinosphere and the
Mikheyev-Smirnov-Wolfenstein effect in outer layers for time-dependent neutrino
energy spectra. Abundances of Li and heavy isotopes Nb, Tc
and La are reduced by a factor of 1.5-2.0 by the -SI. In contrast,
B is relatively insensitive to the -SI. We find that the abundance
ratio of heavy to light nucleus, La/B, is sensitive to the
neutrino mass hierarchy, and the normal mass hierarchy is more likely to be
consistent with the solar abundances
Pentaquark baryon production from photon-neuteron reactions
Extending the hadronic Lagrangians that we recently introduced for studying
pentaquark baryon production from meson-proton, proton-proton, and
photon-proton reactions near threshold to include the anomalous interaction
between and , we evaluate the cross section for
production from photon-neutron reactions, in which the was first
detected in the SPring-8 experiment in Japan and the CLAS experiment at Thomas
Jefferson National Laboratory. With empirical coupling constants and form
factors, and assuming that the decay width of is 20 MeV, the
predicted cross section is found to have a peak value of about 280 nb, which is
substantially larger than that for production from photon-proton
reactions.Comment: 13 pages, 6 figure
Pentaquark baryon production at the Relativistic Heavy Ion Collider
Production of pentaquark baryons in central relativistic heavy ion
collisions is studied in a kinetic model. Assuming that a quark-gluon plasma is
produced in the collisions, we first determine the number of
produced from the quark-gluon plasma using a parton coalescence model, and then
take into consideration its production and absorption in subsequent hadronic
matter via the reactions ,
, and \piN\leftrightarrow\bar K\Theta. We find
that although the final number is affected by hadronic interactions,
it remains sensitive to the initial number of produced from the
quark-gluon plasma, particularly in the case of a small width as
imposed by the and scattering data. Because of small baryon
chemical potential in the hot dense matter produced in these collisions, the
number of produced anti- is only slightly smaller than that of
.Comment: 6 pages, 2 figures, revised version, to appear in PL
Net-charge probability distributions in heavy ion collisions at chemical freeze-out
We explore net charge probability distributions in heavy ion collisions
within the hadron resonance gas model. The distributions for strangeness,
electric charge and baryon number are derived. We show that, within this model,
net charge probability distributions and the resulting fluctuations can be
computed directly from the measured yields of charged and multi-charged
hadrons. The influence of multi-charged particles and quantum statistics on the
shape of the distribution is examined. We discuss the properties of the net
proton distribution along the chemical freeze-out line. The model results
presented here can be compared with data at RHIC energies and at the LHC to
possibly search for the relation between chemical freeze-out and QCD cross-over
lines in heavy ion collisions.Comment: 21 pages, 6 figure
Comprehensive Analyses of the Neutrino-Process in the Core-collapsing Supernova
We investigate the neutrino flavor change effects due to neutrino
self-interaction, shock wave propagation as well as matter effect on the
neutrino process of the core-collapsing supernova. For the hydrodynamics, we
use two models: a simple thermal bomb model and a specified hydrodynamic model
for SN1987A. As a pre-supernova model, we take an updated model adjusted to
explain the SN1987A employing recent development of the reaction
rates for nuclei near the stability line . As for the neutrino
luminosity, we adopt two different models: equivalent neutrino luminosity and
non-equivalent luminosity models. The latter is taken from the synthetic
analyses of the CCSN simulation data which involved quantitatively the results
obtained by various neutrino transport models. Relevant neutrino-induced
reaction rates are calculated by a shell model for light nuclei and a
quasi-particle random phase approximation model for heavy nuclei. For each
model, we present abundances of the light nuclei (Li, Be, B and
C) and heavy nuclei (Nb, Tc, La and Ta)
produced by the neutrino-process. The light nuclei abundances turn out to be
sensitive to the Mikheyev-Smirnov-Wolfenstein region around ONeMg region while
the heavy nuclei are mainly produced prior to the MSW region. Through the
detailed analyses of the numerical abundances, we find that neutrino
self-interaction becomes a key ingredient in addition to the MSW effect for
understanding the neutrino process and the relevant nuclear abundances.
However, the whole results are shown to depend on the adopted neutrino
luminosity scheme. Detailed evaluations of the nuclear abundances for the two
possible neutrino mass hierarchies are performed with the comparison to the
available meteorite analyses data. The normal mass hierarchy is shown to be
more compatible with the meteoritic data
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