4,472 research outputs found
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
Vector meson spectral function and dilepton rate in an effective mean field model
We have studied the vector meson spectral function (VMSF) in a hot and dense
medium within an effective QCD model namely the Nambu-Jona-Lasinio (NJL) and
its Polyakov Loop extended version (PNJL) with and without the effect of
isoscalar vector interaction (IVI). The effect of the IVI has been taken into
account using the ring approximation. We obtained the dilepton production rate
(DPR) using the VMSF and observed that at moderate temperature it is enhanced
in the PNJL model as compared to the NJL and Born rate due to the suppression
of color degrees of freedom.Comment: 5 pages, 7 figures, conference proceedings of the XXI DAE-BRNS HEP
Symposium, IIT Guwahati, December 2014; to appear in 'Springer Proceedings in
Physics Series
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
Medium magnetizations for longitudinal high-density digital recordings
©2003 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.This paper reports on the influences of magnetic media remanent magnetizations on the output levels in digital magnetic tape and disk recording. While at low densities a high magnetization is required for a high output, a lower magnetization is required at high densities. However, for particular applications, an output near to the maximum can be obtained from a wide range of remanent magnetization values, which suggests possible uses for media with diverse properties
Equilibrium Distribution of Heavy Quarks in Fokker-Planck Dynamics
We obtain within Fokker-Planck dynamics an explicit generalization of
Einstein's relation between drag, diffusion and equilibrium distribution for a
spatially homogeneous system, considering both the transverse and longitudinal
diffusion for dimension n>1. We then provide a complete characterization of
when the equilibrium distribution becomes a Boltzmann/J"uttner distribution,
and when it satisfies the more general Tsallis distribution. We apply this
analysis to recent calculations of drag and diffusion of a charm quark in a
thermal plasma, and show that only a Tsallis distribution describes the
equilibrium distribution well. We also provide a practical recipe applicable to
highly relativistic plasmas, for determining both diffusion coefficients so
that a specific equilibrium distribution will arise for a given drag
coefficient.Comment: 4 pages including 2 figure
Gyromagnetic ratio of rapidly rotating compact stars in general relativity
We numerically calculate equilibrium configurations of uniformly rotating and
charged neutron stars, in the case of insulating material and neglecting the
electromagnetic forces acting on the equilibrium of the fluid. This allows us
to study the behaviour of the gyromagnetic ratio for those objects, when
varying rotation rate and equation of state for the matter. Under the
assumption of low charge and incompressible fluid, we find that the
gyromagnetic ratio is directly proportional to the compaction parameter M/R of
the star, and very little dependent on its angular velocity. Nevertheless, it
seems impossible to have g=2 for these models with low charge-to-mass ratio,
where matter consists of a perfect fluid and where the collapse limit is never
reached.Comment: 11 pages, 6 figures, accepted for publication in Classical and
Quantum Gravit
Rethinking the QCD collisional energy loss
It is shown that to leading order the collisional energy loss of an energetic
parton in the hot quark gluon plasma reads , where
the scale of the coupling is determined by the (parametrically soft) Debye
screening mass. Compared to previous expressions derived by Bjorken and other
authors, , the rectified result takes
into account the running of the coupling, as dictated by quantum corrections
beyond tree level. As one significant consequence, due to asymptotic freedom,
the QCD collisional energy loss becomes independent of the jet energy in the
limit . It is advocated that this resummation improved perturbative
result might be useful to (re-)estimate the collisional energy loss for
temperatures relevant in heavy ion phenomenology.Comment: contribution to "Hot Quarks 2006", Villasimius, Italy, 15-20 May 200
Memory effects in radiative jet energy loss
In heavy-ion collisions the created quark-gluon plasma forms a quickly
evolving background, leading to a time dependent radiative behavior of high
momentum partons traversing the medium. We use the Schwinger Keldysh formalism
to describe the jet evolution as a non-equilibrium process including the
Landau-Pomeranschuk-Migdal effect. Concentrating on photon emission, a
comparison of our results to a quasistatic calculation shows good agreement,
leading to the conclusion that the radiative behavior follows the changes in
the medium almost instantaneously
Work-related injuries sustained by emergency medical technicians and paramedics in Turkey
BACKGROUND: Evaluated in the present study were locations, descriptions, and results of work-related injuries (WRIs) sustained by emergency medical technicians (EMTs) and paramedics in Turkey’s most crowded city, İstanbul. METHODS: After the present study had been accepted by the urban health authority, a questionnaire was emailed to the healthcare personnel of İstanbul’s 195 ambulance stations. RESULTS: Included in the present study were the responses of 901 members of staff (660 EMTs and 241 paramedics), with a mean age of 29.5±6.1 (min: 18; max: 61). The majority of participants (94.9%) had encountered verbal abuse from the public, and 39.8% had encountered physical violence from patients’ relatives. Levels of satisfaction with work in emergency medical services (EMS) was also evaluated, and 510 participants (57.6%) were unhappy. Regarding gender, female employees were more likely to be verbally attacked (p=0.01), while males were more likely to be physically attacked (p=0.001). It was reported that motor vehicle accidents (MVAs) were the most common cause of WRIs (81.4%), followed by needle-stick injuries (52.2%), ocular exposure to blood and other fluids (30.9%), and sharp injuries (22.5%). Only 10.5% (n=95) of WRIs were reported to authorities; 488 (54.2%) of participants just attended to the practice to prevent possible WRIs. CONCLUSION: For paramedics and EMTs, risk of WRI is obviously high. Strategies to decrease and prevent verbal and physical violence should be developed. © 2016 TJTES
Evidence for spin-triplet superconducting correlations in metal-oxide heterostructures with non-collinear magnetization
Heterostructures composed of ferromagnetic La0.7Sr0.3MnO3, ferromagnetic
SrRuO3, and superconducting YBa2Cu3Ox were studied experimentally. Structures
of composition Au/La0.7Sr0.3MnO3/SrRuO3/YBa2Cu3Ox were prepared by pulsed laser
deposition, and their high quality was confirmed by X-ray diffraction and
reflectometry. A non-collinear magnetic state of the heterostructures was
revealed by means of SQUID magnetometry and polarized neutron reflectometry. We
have further observed superconducting currents in mesa-structures fabricated by
deposition of a second superconducting Nb layer on top of the heterostructure,
followed by patterning with photolithography and ion-beam etching. Josephson
effects observed in these mesa-structures can be explained by the penetration
of a triplet component of the superconducting order parameter into the magnetic
layers.Comment: 10 pages, 6 figure
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