299 research outputs found
A Simple Statistical Model for Analysis of QGP-droplet (Fireball) Formation
We construct the density of states for quarks and gluons using the `Thomas -
Fermi model' for atoms and the `Bethe model' for nucleons as templates. With
parameters to take care of the plasma (hydrodynamical) features of the QGP with
a thermal potential for the interaction, we find a window in the parametric
space of the model where observable QGP droplets of 5 fm radius can
occur with transition temperature in the range 140 MeV to 250 MeV. By matching
with the expectations of Lattice Gauge estimates of the QGP-hadron transitions,
we can further narrow the window, thereby restricting the allowed values of the
flow-parameters of the model.Comment: LaTex 11 pages, 8 figure
Nonequilibrium and Parity Effects in the Tunneling Conductance of Ultrasmall Superconducting Grains
Recent experiment on the tunneling spectra of ultrasmall superconducting
grains revealed an unusual structure of the lowest differential conductance
peak for grains in the odd charging states. We explain this behavior by
nonequilibrium ``gapless'' excitations associated with different energy levels
occupied by the unpaired electron. These excitations are generated by inelastic
cotunneling.Comment: 4 pages, 2 .eps figures include
Weak localization in disordered systems at the ballistic limit
The weak localization (WL) contribution to the two-level correlation function
is calculated for two-dimensional disordered conductors. Our analysis extends
to the nondiffusive (ballistic) regime, where the elastic mean path is of order
of the size of the system. In this regime the structure factor (the Fourier
transform of the two-point correlator) exhibits a singular behavior consisting
of dips superimposed on a smooth positive background. The strongest dips appear
at periods of the periodic orbits of the underlying clean system. Somewhat
weaker singularities appear at times which are sums of periods of two such
orbits. The results elucidate various aspects of the weak localization physics
of ballistic chaotic systems.Comment: 13 pages, 13 figure
Many-body theory of the quantum mirage
In recent scanning tunneling microscopy experiments, confinement in an
elliptical corral has been used to project the Kondo effect from one focus to
the other one. I solve the Anderson model at arbitrary temperatures, for an
impurity hybridized with eigenstates of an elliptical corral, each of which has
a resonant level width delta. This width is crucial. If delta < 20 meV, the
Kondo peak disappears, while if delta > 80 meV, the mirage disappears. For
particular conditions, a stronger mirage with the impurity out of the foci is
predicted.Comment: 5 pages, 5 figures. Some clarifications of the method added, and a
reference included to show that the hybridization of the impurity with bulk
states can be neglecte
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