11,133 research outputs found
Estimation of the particle-antiparticle correlation effect for pion production in heavy ion collisions
Estimation of the back-to-back pi-pi correlations arising due to evolution of
the pionic field in the course of pion production process is given for central
heavy nucleus collisions at moderate energies.Comment: 6 LaTeX pages + 5 ps figure
Two-photon correlations as a sign of sharp transition in quark-gluon plasma
The photon production arising due to time variation of the medium has been
considered. The Hamilton formalism for photons in time-variable medium (plasma)
has been developed with application to inclusive photon production. The results
have been used for calculation of the photon production in the course of
transition from quark-gluon phase to hadronic phase in relativistic heavy ion
collisions. The relative strength of the effect as well as specific two- photon
correlations have been evaluated. It has been demonstrated that the opposite
side two-photon correlations are indicative of the sharp transition from the
quark-gluon phase to hadrons.Comment: 23 pages, 2 figure
Hydrodynamic description of transport in strongly correlated electron systems
We develop a hydrodynamic description of the resistivity and
magnetoresistance of an electron liquid in a smooth disorder potential. This
approach is valid when the electron-electron scattering length is sufficiently
short. In a broad range of temperatures, the dissipation is dominated by heat
fluxes in the electron fluid, and the resistivity is inversely proportional to
the thermal conductivity, . This is in striking contrast with the
Stokes flow, in which the resistance is independent of and
proportional to the fluid viscosity. We also identify a new hydrodynamic
mechanism of spin magnetoresistance
Magnetoconductance of carbon nanotube p-n junctions
The magnetoconductance of p-n junctions formed in clean single wall carbon
nanotubes is studied in the noninteracting electron approximation and
perturbatively in electron-electron interaction, in the geometry where a
magnetic field is along the tube axis. For long junctions the low temperature
magnetoconductance is anomalously large: the relative change in the conductance
becomes of order unity even when the flux through the tube is much smaller than
the flux quantum. The magnetoconductance is negative for metallic tubes. For
semiconducting and small gap tubes the magnetoconductance is nonmonotonic;
positive at small and negative at large fields.Comment: 5 pages, 2 figure
Novel relativistic plasma excitations in a gated two-dimensional electron system
The microwave response of a two-dimensional electron system (2DES) covered by
a conducting top gate is investigated in the relativistic regime for which the
2D conductivity . Weakly damped plasma waves are
excited in the gated region of the 2DES. The frequency and amplitude of the
resulting plasma excitations show a very unusual dependence on the magnetic
field, conductivity, gate geometry and separation from the 2DES. We show that
such relativistic plasmons survive for temperatures up to 300 K, allowing for
new room-temperature microwave and terahertz applications.Comment: 9 pages, 7 figure
Frobenius-Perron Resonances for Maps with a Mixed Phase Space
Resonances of the time evolution (Frobenius-Perron) operator P for phase
space densities have recently been shown to play a key role for the
interrelations of classical, semiclassical and quantum dynamics. Efficient
methods to determine resonances are thus in demand, in particular for
Hamiltonian systems displaying a mix of chaotic and regular behavior. We
present a powerful method based on truncating P to a finite matrix which not
only allows to identify resonances but also the associated phase space
structures. It is demonstrated to work well for a prototypical dynamical
system.Comment: 5 pages, 2 figures, 2nd version as published (minor changes
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