40,763 research outputs found
Deconfinement and chiral restoration in nonlocal SU(3) chiral quark models
We study the features of nonlocal SU(3) chiral quark models with wave
function renormalization. Model parameters are determined from meson
phenomenology, considering different nonlocal form factor shapes. In this
context we analyze the characteristics of the deconfinement and chiral
restoration transitions at finite temperature, introducing the couplings of
fermions to the Polyakov loop. We analyze the results obtained for various
thermodynamical quantities considering different Polyakov loop potentials and
nonlocal form factors, in comparison with data obtained from lattice QCD
calculations.Comment: 25 pages, 5 figures. Discussion of results enlarged, figures
modified, references added. Version to appear in Physical Review
Heat Fluctuations in Brownian Transducers
Heat fluctuation probability distribution function in Brownian transducers
operating between two heat reservoirs is studied. We find, both analytically
and numerically, that the recently proposed Fluctuation Theorem for Heat
Exchange [C. Jarzynski and D. K. Wojcik, Phys. Rev. Lett. 92, 230602 (2004)]
has to be modified when the coupling mechanism between both baths is
considered. We also extend such relation when external work is present. Our
work fixes the domain of applicability of the theorem in more realistic
operating systems.Comment: Comments are welcom
Generalized Ginzburg-Landau approach to inhomogeneous phases in nonlocal chiral quark models
We analyze the presence of inhomogeneous phases in the QCD phase diagram
within the framework of nonlocal chiral quark models. We concentrate in
particular in the positions of the tricritical (TCP) and Lifshitz (LP) points,
which are studied in a general context using a generalized Ginzburg-Landau
approach. We find that for all the phenomenologically acceptable model
parametrizations considered the TCP is located at a higher temperature and a
lower chemical potential in comparison with the LP. Consequently, these models
seem to favor a scenario in which the onset of the first order transition
between homogeneous phases is not covered by an inhomogeneous, energetically
favored phase.Comment: 9 pages, 1 figure. V2: Two references added, figure modified, minor
changes in the text introduced. Matches version to be published in Physics
Letters
Inhomogeneous phases in nonlocal chiral quark models
The presence of inhomogeneous phases in the QCD phase diagram is analyzed
within chiral quark models that include nonlocal interactions. We work at the
mean field level, assuming that the spatial dependence of scalar and
pseudo-scalar condensates is given by a dual chiral density wave. Phase
diagrams for Gaussian nonlocal form factors are studied in detail and compared
with those obtained within the Nambu-Jona-Lasinio model and quark-meson
approaches.Comment: 14 pages, 3 figure
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