965 research outputs found
Adiabatic Effective Action for Vortices in Neutral and Charged Superfluids
Adiabatic effective action for vortices in neutral and charged superfluids at
zero temperature are calculated using the topological Landau-Ginzburg theory
recently proposed by Hatsuda, Yahikozawa, Ao and Thouless, and vortex dynamics
are examined. The Berry phase term arising in the effective action naturally
yields the Magnus force in both neutral and charged superfluids.
It is shown that in neutral superfluid there is only one degree of freedom,
namely the center of vorticities, and the vortex energy is proportinal to the
sum of all vorticities so that it is finite only for the vanishing total
vorticity of the system.
On the other hand the effective mass and the vortex energy for a vortex in
charged superfluids are defined individually as expected. The effects of the
vortex core on these quantities are also estimated. The possible depinning
scenario which is governed by the Magnus force and the inertial mass is also
discussed.Comment: 26 page
In-medium pi-pi Correlation Induced by Partial Restoration of Chiral Symmetry
We show that both the linear and the non-linear chiral models give an
enhancement of the pi-pi cross section near the 2pi threshold in the
scalar-iso-scalar (I=J=0) channel in nuclear matter. The reduction of the
chiral condensate, i.e., the partial chiral restoration in nuclear matter, is
responsible for the enhancement in both cases. We extract an effective
4pi-nucleon vertex which is responsible for the enhancement but has not been
considered in the non-liear models for in-medium pi-pi interaction. Relation of
this vertex and a next-to-leading order terms in the heavy-baryon chiral
lagrangian, L_piN^(2), is also discussed.Comment: 5 pages, 5 eps figure, REVTe
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