11,396 research outputs found
Influence of tensor interactions on masses and decay widths of dibaryons
The influence of gluon and Goldstone boson induced tensor interactions on the
dibaryon masses and D-wave decay widths has been studied in the quark
delocalization, color screening model. The effective S-D wave transition
interactions induced by gluon and Goldstone boson exchanges decrease rapidly
with increasing strangeness of the channel. The tensor contribution of K and
mesons is negligible in this model. There is no six-quark state in the
light flavor world studied so far that can become bound by means of these
tensor interactions besides the deuteron. The partial D-wave decay widths of
the N state to spin 0 and 1 final states
are 12.0 keV and 21.9 keV respectively. This is a very narrow dibaryon
resonance that might be detectable in relativistic heavy ion reactions by
existing RHIC detectors through the reconstruction of the vertex mass of the
decay product and by the COMPAS detector at CERN or at JHF in
Japan and the FAIR project in Germany in the future.Comment: 19 pages, 5 figure
Tagging the p n -> d phi reaction by backward protons in p d -> d phi p_{sp} processes
The reaction p d -> d phi p_{sp} is studied within the Bethe-Salpeter
formalism. Under special kinematical conditions (slow backward spectator proton
p_{sp} and fast forward deuteron) relevant for forthcoming experiments at COSY,
the cross section and a set of polarization observables factorize in the
contribution of the pure subprocess p n -> d phi and a contribution stemming
from deuteron quantities and kinematical factors. This provides a theoretical
basis for studying threshold-near processes at quasi-free neutrons
The NN phase shifts in the extended quark-delocalization, color-screening model
An alternative method is applied to the study of nucleon-nucleon(NN)
scattering phase shifts in the framework of extended quark delocalization,
color-screening model(QDCSM), where the one-pion-exchange(OPE) with short-range
cutoff is included.Comment: 5 pages, 3 figures, two-colum
AdS and Lifshitz Black Holes in Conformal and Einstein-Weyl Gravities
We study black hole solutions in extended gravities with higher-order
curvature terms, including conformal and Einstein-Weyl gravities. In addition
to the usual AdS vacuum, the theories admit Lifshitz and Schr\"odinger vacua.
The AdS black hole in conformal gravity contains an additional parameter over
and above the mass, which may be interpreted as a massive spin-2 hair. By
considering the first law of thermodynamics, we find that it is necessary to
introduce an associated additional intensive/extensive pair of thermodynamic
quantities. We also obtain new Liftshitz black holes in conformal gravity and
study their thermodynamics. We use a numerical approach to demonstrate that AdS
black holes beyond the Schwarzschild-AdS solution exist in Einstein-Weyl
gravity. We also demonstrate the existence of asymptotically Lifshitz black
holes in Einstein-Weyl gravity. The Lifshitz black holes arise at the boundary
of the parameter ranges for the AdS black holes. Outside the range, the
solutions develop naked singularities. The asymptotically AdS and Lifshitz
black holes provide an interesting phase transition, in the corresponding
boundary field theory, from a relativistic Lorentzian system to a
non-relativistic Lifshitz system.Comment: typos corrected, references adde
Magnetically Robust Non-Fermi Liquid Behavior in Heavy Fermion Systems with f^2-Configuration: Competition between Crystalline-Electric-Field and Kondo-Yosida Singlets
We study a magnetic field effect on the Non-Fermi Liquid (NFL) which arises
around the quantum critical point (QCP) due to the competition between the
f^2-crystalline-electric-field singlet and the Kondo-Yosida singlet states by
using the numerical renormalization ground method. We show the characteristic
temperature T_F^*, corresponding to a peak of a specific heat, is not affected
by the magnetic field up to H_z^* which is determined by the distance from the
QCP or characteristic energy scales of each singlet states. As a result, in the
vicinity of QCP, there are parameter regions where the NFL is robust against
the magnetic field, at an observable temperature range T > T_F^*, up to H_z^*
which is far larger than T_F^* and less than min(T_{K2}, $Delta).Comment: 8 pages, 9 figur
Are spectroscopic factors from transfer reactions consistent with asymptotic normalisation coefficients?
It is extremely important to devise a reliable method to extract
spectroscopic factors from transfer cross sections. We analyse the standard
DWBA procedure and combine it with the asymptotic normalisation coefficient,
extracted from an independent data set. We find that the single particle
parameters used in the past generate inconsistent asymptotic normalization
coefficients. In order to obtain a consistent spectroscopic factor,
non-standard parameters for the single particle overlap functions can be used
but, as a consequence, often reduced spectroscopic strengths emerge. Different
choices of optical potentials and higher order effects in the reaction model
are also studied. Our test cases consist of: C(d,p)C(g.s.) at
MeV, O(d,p)O(g.s.) at MeV and
Ca(d,p)Ca(g.s.) at MeV. We underline the
importance of performing experiments specifically designed to extract ANCs for
these systems.Comment: 15 pages, 12 figures, Phys. Rev. C (in press
Evidence for local aldosterone synthesis in the large intestine of the mouse
Aldosterone, the main physiological mineralocorticoid, regulates sodium and potassium balance in the distal convoluted tubule of the kidney. Aldosterone is synthesized from cholesterol in the adrenal cortex in a sequence of enzymatic steps. Recently however, several tissues or cells e.g. brain, heart, blood vessels, kidneys and adipocytes have been shown to possess capability to produce aldosterone locally, and there is some evidence that this occurs also in the intestine. Colon expresses mineralocorticoid receptors and is capable of synthesizing corticosterone, the second last intermediate on the route to aldosterone from cholesterol. Based on such reports and on our preliminary finding, we hypothesized that aldosterone could be synthesized locally in the intestine and therefore we measured the concentration of aldosterone as well as the protein and gene expression of aldosterone synthase (CYP11B2), an enzyme responsible on aldosterone synthesis, from the distal section of the gastrointestinal tract of 10-week-old Balb/c male mice. It is known that sodium deficiency regulates aldosterone synthesis in adrenal glands, therefore we fed the mice with low (0.01%), normal (0.2%) and high-sodium (1.6%) diets for 14 days. Here we report that, aldosterone was detected in colon and cecum samples. Measurable amounts of CYP11B2 protein were detected by Western blot and Elisa analysis from both intestinal tissues. We detected CYP1182 gene expression from the large intestine along with immunohistochemical findings of CYP11B2 in colonic wall. Sodium depletion increased the aldosterone concentration in plasma compared to control and high-sodium groups as well as in the intestine compared to mice fed with the high-sodium diet. To summarize, this study further supports the presence of aldosterone and the enzyme needed to produce this mineralocorticoid in the murine large intestine.Peer reviewe
Transient Analysis of Warm Electron Injection Programming of Double Gate SONOS Memories by means of Full Band Monte Carlo Simulation
In this paper we investigate "Warm Electron Injection" as a mechanism for NOR
programming of double-gate SONOS memories through 2D full band Monte Carlo
simulations. Warm electron injection is characterized by an applied VDS smaller
than 3.15 V, so that electrons cannot easily accumulate a kinetic energy larger
than the height of the Si/SiO2 barrier. We perform a time-dependent simulation
of the program operation where the local gate current density is computed with
a continuum-based method and is adiabatically separated from the 2D full Monte
Carlo simulation used for obtaining the electron distribution in the phase
space. In this way we are able to compute the time evolution of the charge
stored in the nitride and of the threshold voltages corresponding to forward
and reverse bias. We show that warm electron injection is a viable option for
NOR programming in order to reduce power supply, preserve reliability and CMOS
logic level compatibility. In addition, it provides a well localized charge,
offering interesting perspectives for multi-level and dual bit operation, even
in devices with negligible short channel effects
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