1,557 research outputs found
Comments on Baryon Melting in Quark Gluon Plasma with Gluon Condensation
We consider a black hole solution with a non-trivial dilaton from IIB super
gravity which is expected to describe a strongly coupled hot gauge plasma with
non-vanishing gluon condensation present. We construct a rotating and moving
baryon to probe the screening and phases of the plasma. Melting of the baryons
in hot plasma in this background had been studied previously, however, we show
that baryons melt much lower temperature than has been suggested previously.Comment: 3 figures, 12 page
A Dual Geometry of the Hadron in Dense Matter
We identify the dual geometry of the hadron phase of dense nuclear matter and
investigate the confinement/deconfinement phase transition. We suggest that the
low temperature phase of the RN black hole with the full backreaction of the
bulk gauge field is described by the zero mass limit of the RN black hole with
hard wall. We calculated the density dependence of critical temperature and
found that the phase diagram closes. We also study the density dependence of
the rho meson mass.Comment: 16 pages, 4 figures, typos corrected, references adde
Modulation of SIRT1-foxo1 signaling axis by resveratrol: Implications in skeletal muscle aging and insulin resistance
© 2015 S. Karger AG, Basel. Aging individuals and diabetic patients often exhibit concomitant reductions of skeletal muscle mass/strength and insulin sensitivity, suggesting an intimate link between muscle aging and insulin resistance. Foxo1, a member of the FOXO transcription factor family, is an important player in insulin signaling due to its inhibitory role in glucose uptake and utilization in skeletal muscle. Phosphorylation of Foxo1 is thought to mitigate the transactivation of pyruvate dehydrogenase lipoamide kinase 4 (PDK4), which is a negative regulator of the glycolytic enzyme pyruvate dehydrogenase (PDH). In contrast, how aging would regulate acetylation/deacetylation machineries and glucose utilization in skeletal muscle through the Foxo1/PDH axis remains largely undetermined. Accumulating body of evidence have shown that resveratrol, a natural polyphenol in grapes and red wine, activates the longevity-related protein sirtuin 1 (SIRT1) and augments insulin sensitivity in addition to its well-documented effects on mitochondrial energetics. The present review summarizes the role of Foxo1/SIRT1 in insulin signaling in skeletal muscle and proposes the insight that activation of SIRT1 deacetylase activity to deacetylate and suppress the Foxo1-induced transactivation of PDK4 may represent an anti-hyperglycemic mechanism of resveratrol in aging skeletal muscle.Link_to_subscribed_fulltex
The Dropping of In-Medium Hadron Mass in Holographic QCD
We study the baryon density dependence of the vector meson spectrum using the
D4/D6 system together with the compact D4 baryon vertex. We find that the
vector meson mass decreases almost linearly in density at low density for small
quark mass, but saturates to a finite non-zero value for large density. We also
compute the density dependence of the mass and the
velocity. We find that in medium, our model is consistent with the GMOR
relation up to a few times the normal nuclear density. We compare our hQCD
predictions with predictions made based on hidden local gauge theory that is
constructed to model QCD.Comment: 20 pages, 7 figure
Chiral Condensate in Holographic QCD with Baryon Density
We consider the chiral condensate in the baryonic dense medium using the
generalized Sakai-Sugimoto model. It is defined as the vacuum expectation value
of open Wilson line that is proposed to be calculated by use of the area of
world-sheet instanton. We evaluate it in confined as well as deconfined phase.
In both phases, the chiral condensate has a minimum as a function of baryon
density. In the deconfined phase, taking into account the chiral symmetry
restoration, we classify the behavior of chiral condensate into three types.
One can set the parameter of the theory such that the results, in low but
sufficiently higher density, is in agreement with the expectation from QCD.Comment: 23 pages, 8 figure
Cold Dense Baryonic Matter and Compact Stars
Probing dense hadronic matter is thus far an uncharted field of physics. Here
we give a brief summary of the highlights of what has been so far accomplished
and what will be done in the years ahead by the World Class University III
Project at Hanyang University in the endeavor to unravel and elucidate the
multifacet of the cold dense baryonic matter existing in the interior of the
densest visible stable object in the Universe, i.e., neutron stars, strangeness
stars and/or quark stars, from a modest and simplified starting point of an
effective field theory modeled on the premise of QCD as well as from a gravity
dual approach of hQCD. The core of the matter of our research is the possible
origin of the of the proton mass that is to be accounted for and how
the "vacuum" can be tweaked so that the source of the mass generation can be
uncovered by measurements made in terrestrial as well as space laboratories.
Some of the issues treated in the program concern what can be done - both
theoretically and experimentally - in anticipation of what's to come for basic
physics research in Korea.Comment: 23 pages, 8 figures; Based on the review prepared for the "2011 World
Class University (WCU) International Conference," August 2011, Seoul, Kore
Light-cone Gauge Superstring Field Theory and Dimensional Regularization II
We propose a dimensional regularization scheme to deal with the divergences
caused by colliding supercurrents inserted at the interaction points, in the
light-cone gauge NSR superstring field theory. We formulate the theory in
dimensions and define the amplitudes as analytic functions of . With an
appropriately chosen three-string interaction term and large negative , the
tree level amplitudes for the (NS,NS) closed strings can be recast into a BRST
invariant form, using the superconformal field theory proposed in
Ref.[arXiv:0911.3704]. We show that in the limit they coincide with
the results of the first quantized theory. Therefore we obtain the desired
results without adding any contact interaction terms to the action.Comment: 23 pages; v2: minor modifications; v3: revised argument in section 3,
added appendix C, results unchanged; v4: added clarifications, two figures
and a footnote; v5: minor modification
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