418 research outputs found
HBT Effect Based on a Hydrodynamical Model
We investigate HBT radii based on the numerical solutions of the
hydrodynamical model which are so tuned as to reproduce the recent experimental
data at the CERN SPS. Comparing the sizes of freeze-out hypersurface with HBT
radii, we discuss dynamical effect of the systematic flow on the apparent HBT
radii. Finally we compare HBT radii of the QGP phase transition model with
those of the hadron gas model without phase transition.Comment: 5 pages, LaTeX, 7 EPS figures. Talk at the International School on
the Physics of Quark Gluon Plasma, June 3-6, 1997, Hiroshima, Japa
Two-particle correlation from a relativistic fluid with a first order phase transition
We numerically calculate two-particle correlation functions of CERN-SPS 158
A GeV Pb+Pb central collisions based on a (3+1)-dimensional relativistic
hydrodynamics with a first order phase transition. We analyze the pair momentum
dependence of pion source sizes extracted from the
Yano-Koonin-Podgoretski\u{\i} (YKP) parametrization which is expected to give
the source sizes directly. We find that, even in the case of the first order
phase transition, the collective expansion and surface dominant freeze-out of
the fluid naturally lead to the opaque source for which the interpretation of
the temporal source parameter as the emission duration breaks down.Comment: LaTeX, 4pages, 2 figures. To appear in the Proceedings of the
International Conference on Quark Nuclear Physics, Adelaide, Australia, 21-25
February, 200
Drastic enhancement of the thermal Hall angle in a -wave superconductor
A drastic enhancement of the thermal Hall angle in -wave superconductors
was observed experimentally in a cuprate superconductor and in CeCoIn at
low temperatures and very weak magnetic field [Phys. Rev. Lett. , 890
(2001); Phys. Rev. B , 214515 (2005)]. However, to the best of our
knowledge, its microscopic calculation has not been performed yet. To study
this microscopically, we derive the thermal Hall coefficient in extreme type-II
superconductors with an isolated pinned vortex based on the augmented
quasiclassical equations of superconductivity with the Lorentz force. Using it,
we can confirm that the quasiparticle relaxation time and the thermal Hall
angle are enhanced in -wave superconductors without impurities of the
resonant scattering because quasiparticles around the gap nodes which become
dominant near zero temperature are restricted to the momentum in a specific
orientation. This enhancement of the thermal Hall angle may also be observed in
other nodal superconductors with large magnetic-penetration depth.Comment: 11 pages, 11 figure
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