2,238 research outputs found
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
Diffusion in an Expanding Plasma using AdS/CFT
We consider the diffusion of a non-relativistic heavy quark of fixed mass M,
in a one-dimensionally expanding and strongly coupled plasma using the AdS/CFT
duality. The Green's function constructed around a static string embedded in a
background with a moving horizon, is identified with the noise correlation
function in a Langevin approach. The (electric) noise decorrelation is of order
1/T(\tau) while the velocity de-correlation is of order MD(\tau)/T(\tau). For
MD>1, the diffusion regime is segregated and the energy loss is Langevin-like.
The time dependent diffusion constant D(\tau) asymptotes its adiabatic limit
2/\pi\sqrt{\lambda} T(\tau) when \tau/\tau_0=(1/3\eta_0\tau_0)^3 where \eta_0
is the drag coefficient at the initial proper time \tau_0.Comment: 19 pages, 2 figures, minor corrections, version to appear in JHE
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
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
Exploring the multi-humped fission barrier of 238U via sub-barrier photofission
The photofission cross-section of 238U was measured at sub-barrier energies
as a function of the gamma-ray energy using, for the first time, a
monochromatic, high-brilliance, Compton-backscattered gamma-ray beam. The
experiment was performed at the High Intensity gamma-ray Source (HIgS) facility
at beam energies between E=4.7 MeV and 6.0 MeV and with ~3% energy resolution.
Indications of transmission resonances have been observed at gamma-ray beam
energies of E=5.1 MeV and 5.6 MeV with moderate amplitudes. The triple-humped
fission barrier parameters of 238U have been determined by fitting EMPIRE-3.1
nuclear reaction code calculations to the experimental photofission cross
section.Comment: 5 pages, 3 figure
Superconductivity from D3/D7: Holographic Pion Superfluid
We show that a D3/D7 system (at zero quark mass limit) at finite isospin
chemical potential goes through a superconductor (superfluid) like phase
transition. This is similar to a flavored superfluid phase studied in QCD
literature, where mesonic operators condensate. We have studied the frequency
dependent conductivity of the condensate and found a delta function pole in the
zero frequency limit. This is an example of superconductivity in a string
theory context. Consequently we have found a superfluid/supercurrent type
solution and studied the associated phase diagram. The superconducting
transition changes from second order to first order at a critical superfluid
velocity. We have studied various properties of the superconducting system like
superfluid density, energy gap, second sound etc. We investigate the
possibility of the isospin chemical potential modifying the embedding of the
flavor branes by checking whether the transverse scalars also condense at low
temperature. This however does not seem to be the case.Comment: 18 pages, 8 figures, revtex
Robust Modifications of the Levene and OâBrien Tests for Spread
Variants of Leveneâs and OâBrienâs procedures not investigated by Keselman, Wilcox & Algina (2008) were examined. Simulations indicate that a new OâBrien variant provides very good Type I error control and is simpler for applied researchers to compute than the method recommended by Keselman, et al
Bulk Filling Branes and the Baryon Density in AdS/QCD with gravity back-reaction
We consider the gravity back reaction on the metric due to the baryon density
in effective ads/qcd model by reconsidering the role of the charged AdS black
hole. Previously it has been known that the U(1) charge is dual to the
R-charge. Here we point out that if we consider the case where is
completely filled with flavor branes, the gravity back reaction produces
charged AdS black hole where the effect of charge on the metric is proportional
to . As a consequence, phase diagram changes qualitatively if we allow
finite: it closes at the finite density unlike the probe brane
embedding approach.
Another issue we discuss here is the question whether there is any chemical
potential dependence in the confining phase. We consider this problem in the
hard wall model with baryon charge. We conclude that there is a non-trivial
dependence on the chemical potential in this case also.Comment: 17 pages 3x2 figures, v2: references added;v3 published version,
title change and reference adde
Mixed RG Flows and Hydrodynamics at Finite Holographic Screen
We consider quark-gluon plasma with chemical potential and study
renormalization group flows of transport coefficients in the framework of
gauge/gravity duality. We first study them using the flow equations and compare
the results with hydrodynamic results by calculating the Green functions on the
arbitrary slice. Two results match exactly. Transport coefficients at arbitrary
scale is ontained by calculating hydrodynamics Green functions. When either
momentum or charge vanishes, transport coefficients decouple from each other.Comment: 22 pages, 6 figure
Participatory asset mapping and photovoice interviews to scope cultural and community resources to reduce alcohol harm in Chitwan, Nepal
Aims:
To scope the breadth of existing cultural and community assets and how alcohol drinkers and community health workers perceived them in relation to reducing alcohol-related harm.
Methods:
The study was conducted in Chitwan, south-central Nepal, which has considerable alcohol problems. Participatory asset mapping was conducted using field notes, photography, and through engaging with communities to explore how community assets affect alcohol consumption. Semi-structured photovoice interviews were conducted with harmful/hazardous drinkers (AUDIT score 8 to 19) and community health workers. Purposive and snowball sampling were used to recruit participants. During interviews, participants used their photographs to reflect on how community assets influenced alcohol use. Thematic framework analysis was used to analyse the data.
Results:
We recruited 12 harmful/hazardous drinkers (3 females) and 6 health workers (2 females). The mean AUDIT score of the former was 12.17 (SD ±2.86). Thematic analysis of the photovoice interviews produced three themes: âinfluences and impact of families and communitiesâ; âculture and spiritualityâ; and ânature and the environmentâ. The community mapping produced five assets that promoted alcohol consumption: (1) availability; (2) advertising; (3) negative attitudes towards users; (4) festivals/gatherings; and (5) illiteracy/poverty. Six assets that discouraged consumption were: (1) legislation restricting use; (2) community organisations; (3) cultural/spiritual sites; (4) healthcare facilities; (5) family and communities; and (6) womenâs community groups. Those from certain ethnic groups consumed more alcohol, experienced more family discord, or felt stigmatised due to their drinking. Assets âfestivals/gatheringsâ and ânegative attitudes toward usersâ and the theme âfamily and communitiesâ concerned with relationships and community activities were perceived to both promote and reduce alcohol use.
Conclusions:
This study provides new insight into a variety of cultural and community assets that promote and reduce alcohol use. The study identifies new possibilities to build on visual participatory and arts-based methods that have potential to be effectively implemented at scale
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