9,147 research outputs found
Virial coefficients from 2+1 dimensional QED effective actions at finite temperature and density
From spinor and scalar 2+1 dimensional QED effective actions at finite
temperature and density in a constant magnetic field background, we calculate
the corresponding virial coefficients for particles in the lowest Landau level.
These coefficients depend on a parameter theta related to the time-component of
the gauge field, which plays an essential role for large gauge invariance. The
variation of the parameter theta might lead to an interpolation between
fermionic and bosonic virial coefficients, although these coefficients are
singular for theta=pi/2.Comment: 10 Latex pages, no figures. Version to appear in MPL
Generalized partition functions and interpolating statistics
We show that the assumption of quasiperiodic boundary conditions (those that
interpolate continuously periodic and antiperiodic conditions) in order to
compute partition functions of relativistic particles in 2+1 space-time can be
related with anyonic physics. In particular, in the low temperature limit, our
result leads to the well known second virial coefficient for anyons. Besides,
we also obtain the high temperature limit as well as the full temperature
dependence of this coefficient.Comment: 12 pages, Latex, updated and enlarged versio
Mais de 170 cultivares transgênicas são disponibilizadas no mercado de sementes do Brasil para a safra 2011/12.
bitstream/item/39191/1/mais-170.pd
Anharmonic oscillation effect on the Davydov-Scott monomer in thermal bath
The dynamics of Davydov-Scott monomer in a thermal bath with higher order
amide-site's displacement leads to anharmonic oscillation effect is
investigated using full-quantum approach and the Lindblad formulation of master
equation. The specific heat is calculated based on the thermodynamic partition
function using the path integral method. The temperature dependence of the
specific heat is studied. In the model the specific heat anomaly as pointed out
in recent works by Ingold et.al is also observed. However it is found that the
anomaly occurs at high temperature region, and the anharmonic oscillation
restores the positivity of specific heat.Comment: 11 pages, 5 figure
Pion and Vector Meson Form Factors in the Kuperstein-Sonnenschein holographic model
We study phenomenological aspects of the holographic model of chiral symmetry
breaking recently introduced by Kuperstein and Sonnenschein (KS). As a first
step, we calculate the spectrum of vector and axial-vector mesons in the KS
model. We numerically compute various coupling constants of the mesons and
pions. Our analysis indicates that vector meson dominance is realized in this
model. The pion, vector meson and axial-vector meson form factors are obtained
and studied in detail. We find good agreement with QCD results. In particular,
the pion form factor closely matches available experimental data.Comment: v1: 27 pages, 9 figures, 4 tables; v2: minor changes, added more
general discussion of vector meson dominance; v3: minor changes and
additions, version accepted for publication in JHE
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