9,838 research outputs found
Position-dependent-mass; Cylindrical coordinates, separability, exact solvability, and PT-symmetry
The kinetic energy operator with position-dependent-mass in cylindrical
coordinates is obtained. The separability of the corresponding Schr\"odinger
equation is discussed within radial cylindrical mass settings. Azimuthal
symmetry is assumed and spectral signatures of various z-dependent interaction
potentials (Hermitian and non-Hermitian PT-symmetric) are reported.Comment: 16 page
Gamma flashes from relativistic electron-positron plasma droplets
Ultra-intense lasers are expected to produce, in near future, relativistic
electron-positron plasma droplets. Considering the local photon production rate
in complete leading order in quantum electrodynamics (QED), we point out that
these droplets are interesting sources of gamma ray flashesComment: 4 pages, 6 figures; Text has been revised and new refs. are adde
Part of the D - dimensional Spiked harmonic oscillator spectra
The pseudoperturbative shifted - l expansion technique PSLET [5,20] is
generalized for states with arbitrary number of nodal zeros. Interdimensional
degeneracies, emerging from the isomorphism between angular momentum and
dimensionality of the central force Schrodinger equation, are used to construct
part of the D - dimensional spiked harmonic oscillator bound - states. PSLET
results are found to compare excellenly with those from direct numerical
integration and generalized variational methods [1,2].Comment: Latex file, 20 pages, to appear in J. Phys. A: Math. & Ge
Bound - states for truncated Coulomb potentials
The pseudoperturbative shifted - expansion technique PSLET is generalized
for states with arbitrary number of nodal zeros. Bound- states energy
eigenvalues for two truncated coulombic potentials are calculated using PSLET.
In contrast with shifted large-N expansion technique, PSLET results compare
excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge
Can Van Hove singularities be observed in relativistic heavy-ion collisions ?
Based on general arguments the in-medium quark propagator in a quark-gluon
plasma leads to a quark dispersion relation consisting of two branches, of
which one exhibits a minimum at some finite momentum. This results in a
vanishing group velocity for collective quark modes. Important quantities such
as the production rate of low mass lepton pairs and mesonic correlators depend
inversely on this group velocity. Therefore these quantities, which follow from
self energy diagrams containing a quark loop, are strongly affected by Van Hove
singularities (peaks and gaps). If these sharp structures could be observed in
relativistic heavy-ion collisions it would reveal the physical picture of the
QGP as a gas of quasiparticles.Comment: 12 pages including nine figures and style files, invited talk given
at the ICPAQGP-2001, November 26-30, 2001, Jaipur, Indi
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