192 research outputs found
Phase separation in asymmetrical fermion superfluids
Motivated by recent developments on cold atom traps and high density QCD we
consider fermionic systems composed of two particle species with different
densities. We argue that a mixed phase composed of normal and superfluid
components is the energetically favored ground state. We suggest how this phase
separation can be used as a probe of fermion superfluidity in atomic traps.Comment: 9 pages, LaTeX2e, version to appear in Phys.Rev.Let
Superfluid phases of the three-species fermion gas
We discuss the zero temperature phase diagram of a dilute gas with three
fermionic species. We make use of solvable limits to conjecture the behavior of
the system in the "unitary" regions. The physics of the Thomas-Efimov effect
plays a role in these considerations. We find a rich phase diagram with
superfluid, gapless superfluid and inhomogeneous phases with different symmetry
breaking patterns. We then discuss one particular possible experimental
implementation in a system of ^6Li atoms and the possible phases arising in
this system as an external magnetic field is varied across three overlaping
Feshbach resonances. We also suggest how to experimentally distinguish the
different phases.Comment: 4 pages, 1 figure, typos corrected and references adde
Renormalization of the Three-Body System with Short-Range Interactions
We discuss renormalization of the non-relativistic three-body problem with
short-range forces. The problem becomes non-perturbative at momenta of the
order of the inverse of the two-body scattering length, and an infinite number
of graphs must be summed. This summation leads to a cutoff dependence that does
not appear in any order in perturbation theory. We argue that this cutoff
dependence can be absorbed in a single three-body counterterm and compute the
running of the three-body force with the cutoff. We comment on relevance of
this result for the effective field theory program in nuclear and molecular
physics.Comment: 5 pages, RevTex, 4 PS figures included with epsf.sty, some clarifying
comments added, version to appear in Phys. Rev. Let
Nucleon-Nucleon Scattering From Fully-Dynamical Lattice QCD
We present results of the first fully-dynamical lattice QCD determination of
nucleon-nucleon scattering lengths in the 1S0 channel and 3S1-3D1 coupled
channels. The calculations are performed with domain-wall valence quarks on the
MILC staggered configurations with lattice spacing of b=0.125 fm in the
isospin-symmetric limit, and in the absence of electromagnetic interactions.Comment: 4 pages, 4 figure
How To Classify 3-Body Forces -- And Why
For systems with only short-range forces and shallow 2-body bound states, the
typical strength of any 3-body force in all partial-waves, including external
currents, is systematically estimated by renormalisation-group arguments in the
Effective Field Theory of Point-Like Interactions. The underlying principle and
some consequences in particular in Nuclear Physics are discussed.Comment: 7 pages LaTeX2e using FBSart-class (provided); 2 figures in 3 .eps
files included using graphicx; to appear in Few-Body System
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