1,274 research outputs found
Fermi liquid theory of ultra-cold trapped Fermi gases: Implications for Pseudogap Physics and Other Strongly Correlated Phases
We show how Fermi liquid theory can be applied to ultra-cold Fermi gases,
thereby expanding their "simulation" capabilities to a class of problems of
interest to multiple physics sub-disciplines. We introduce procedures for
measuring and calculating position dependent Landau parameters. This lays the
ground work for addressing important controversial issues: (i) the suggestion
that thermodynamically, the normal state of a unitary gas is indistinguishable
from a Fermi liquid (ii) that a fermionic system with strong repulsive contact
interactions is associated with either ferromagnetism or localization; this
relates as well to He and its p-wave superfluidity.Comment: 4 pages, 2 figures, revised versio
Meson Supercurrent State in High Density QCD
We study the effect of a non-zero strange quark mass on the
color-flavor-locked (CFL) phase of high density quark matter. We have
previously shown that for a strange quark mass
the CFL state becomes unstable toward the formation of a neutral kaon
condensate. Recently, several authors discovered that for the CFL state contains gapless fermions, and that the gapless modes
lead to an instability in current-current correlation functions. Using an
effective theory of the CFL state we demonstrate that this instability is
resolved by the formation of an inhomogeneous meson condensate, analogous to
Migdal's p-wave pion condensate. This state has a non-zero meson current which
is canceled by a backflow of gapless fermions.Comment: 4 pages, one figure, revised version, to appear in PRL (title changed
in journal
Coulomb corrections to the three-body correlation function in high-energy heavy ion reactions
Starting from an asymptotically correct three-body Coulomb wave-function, we
determine the effect of Coulomb final state interaction on the three-particle
Bose-Einstein correlation function of similarly charged particles. We
numerically estimate that the Riverside approximation is not precise enough to
determine the three-body Coulomb correction factor in the correlation function,
if the characteristic HBT radius parameter is 5 - 10 fm, which is the range of
interest in high-energy heavy ion physics.Comment: 14 pages, 4 figure
Viscosities of Quark-Gluon Plasmas
The quark and gluon viscosities are calculated in quark-gluon plasmas to
leading orders in the coupling constant by including screening. For weakly
interaction QCD and QED plasmas dynamical screening of transverse interactions
and Debye screening of longitudinal interactions controls the infrared
divergences. For strongly interacting plasmas other screening mechanisms taken
from lattice calculations are employed. By solving the Boltzmann equation for
quarks and gluons including screening the viscosity is calculated to leading
orders in the coupling constant. The leading logarithmic order is calculated
exactly by a full variational treatment. The next to leading orders are found
to be very important for sizable coupling constants as those relevant for the
transport properties relevant for quark-gluon plasmas created in relativistic
heavy ion collisions and the early universe.Comment: 12 pages + 6 figures, report LBL-3492
Vortex states of rapidly rotating dilute Bose-Einstein condensates
We show that, in the Thomas-Fermi regime, the cores of vortices in rotating
dilute Bose-Einstein condensates adjust in radius as the rotation velocity,
, grows, thus precluding a phase transition associated with core
overlap at high vortex density. In both a harmonic trap and a rotating
hard-walled bucket, the core size approaches a limiting fraction of the
intervortex spacing. At large rotation speeds, a system confined in a bucket
develops, within Thomas-Fermi, a hole along the rotation axis, and eventually
makes a transition to a giant vortex state with all the vorticity contained in
the hole.Comment: 4 pages, 2 figures, RevTex4. Version as published; discussion
extended, some references added and update
Convergence of the Linear Delta Expansion in the Critical O(N) Field Theory
The linear delta expansion is applied to the 3-dimensional O(N) scalar field
theory at its critical point in a way that is compatible with the large-N
limit. For a range of the arbitrary mass parameter, the linear delta expansion
for converges, with errors decreasing like a power of the order n in
delta. If the principal of minimal sensitivity is used to optimize the
convergence rate, the errors seem to decrease exponentially with n.Comment: 26 pages, latex, 8 figure
Sympathetic cooling route to Bose-Einstein condensate and Fermi-liquid mixtures
We discuss a sympathetic cooling strategy that can successfully mitigate
fermion-hole heating in a dilute atomic Fermi-Bose mixture and access the
temperature regime in which the fermions behave as a Fermi liquid. We introduce
an energy-based formalism to describe the temperature dynamics with which we
study a specific and promising mixture composed of 6Li and 87Rb. Analyzing the
harmonically trapped mixture, we find that the favourable features of this
mixture are further enhanced by using different trapping frequencies for the
two species.Comment: 4 pages, 2 figure
Landau parameters for isospin asymmetric nuclear matter based on a relativistic model of composite and finite extension nucleons
We study the properties of cold asymmetric nuclear matter at high density,
applying the quark meson coupling model with excluded volume corrections in the
framework of the Landau theory of relativistic Fermi liquids. We discuss the
role of the finite spatial extension of composite baryons on dynamical and
statistical properties such as the Landau parameters, the compressibility, and
the symmetry energy. We have also calculated the low lying collective
eigenfrequencies arising from the collisionless quasiparticle transport
equation, considering both unstable and stable modes. An overall analysis of
the excluded volume correlations on the collective properties is performed.Comment: 24 pages, 6 figure
Spin waves in quasi-equilibrium spin systems
Using the Landau Fermi liquid theory we have discovered a new regime for the
propagation of spin waves in a quasi-equilibrium spin systems. We have
determined the dispersion relation for the transverse spin waves and found that
one of the modes is gapless. The gapless mode corresponds to the precessional
mode of the magnetization in a paramagnetic system in the absence of an
external magnetic field. One of the other modes is gapped which is associated
with the precession of the spin current around the internal field. The gapless
mode has a quadratic dispersion leading to some interesting thermodynamic
properties including a contribution to the specific heat. We also
show that these modes make significant contributions to the dynamic structure
function.Comment: 4 pages, 3 figure
Comparison of the extended linear sigma model and chiral perturbation theory
The pion-nucleon scattering amplitudes are calculated in tree approximation
with the use of the extended linear sigma model (ELSM) as well as heavy baryon
chiral perturbation theory (HBPT), and the non-relativistic forms of the
ELSM results are compared with those of HBPT. We find that the amplitudes
obtained in ELSM do not agree with those derived from the more fundamental
effective approach, HBPT.Comment: 7 page
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