22,313 research outputs found
On the duality of three-dimensional superfield theories
Within the superfield approach, we consider the duality between the
supersymmetric Maxwell-Chern-Simons and self-dual theories in three spacetime
dimensions. Using a gauge embedding method, we construct the dual theory to the
self-dual model interacting with a matter superfield, which turns out to be not
the Maxwell-Chern-Simons theory coupled to matter, but a more complicated
model, with a ``restricted'' gauge invariance. We stress the difficulties in
dualizing the self-dual field coupled to matter into a theory with complete
gauge invariance. After that, we show that the duality, achieved between these
two models at the tree level, also holds up to the lowest order quantum
corrections.Comment: 18 pages,2 figures, revtex4, v2: corrected reference
Complete Fusion Enhancement and Suppression of Weakly Bound Nuclei at Near Barrier Energies
We consider the influence of breakup channels on the complete fusion of
weakly bound systems in terms of dynamic polarization potentials. It is argued
that the enhancement of the cross section at sub-barrier energies may be
consistent with recent experimental observations that nucleon transfer, often
leading to breakup, is dominant compared to direct breakup. The main trends of
the experimental complete fusion cross section for Li + Bi are
analyzed in the framework of the DPP approach.Comment: 12 pages, 2 figure
Continuum-continuum coupling and polarization potentials for weakly bound system
We investigate the influence of couplings among continuum states in
collisions of weakly bound nuclei. For this purpose, we compare cross sections
for complete fusion, breakup and elastic scattering evaluated by continuum
discretized coupled channel (CDCC) calculations, including and not including
these couplings. In our study, we discuss this influence in terms of the
polarization potentials that reproduce the elastic wave function of the coupled
coupled channel method in single channel calculations. We find that the
inclusion of couplings among the continuum states renders the real part of the
polarization potential more repulsive, whereas it leads to weaker apsorption to
the breakup channel. We show that the non-inclusion of continuum-continuum
couplings in CDCC calculations may not lead to qualitative and quantitative
wrong conclusions.Comment: 4 pages, 4 figures. Submitted to Phys. Rev.
Assessing the adequacy of the bare optical potential in near-barrier fusion calculation
We critically examine the differences among the different bare nuclear
interactions used in near-barrier heavy ion fusion analysis and
Coupled-Channels calculations, and discuss the possibility of extracting the
barrier parameters of the bare potential from above-barrier data. We show that
the choice of the bare potential may be critical for the analysis of the fusion
cross sections. We show also that the barrier parameters taken from above
barrier data may be very wrong.Comment: 8 pages, 3 tables, 8 figures. Submitted to Physical Review
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