226 research outputs found
The dependence of strange hadron multiplicities on the speed of hadronization
Hadron multiplicities are calculated in the ALCOR model for the Pb+Pb
collisions at CERN SPS energy. Considering the newest experimental results, we
display our prediction obtained from the ALCOR model for stable hadrons
including strange baryons and anti-baryons.Comment: 8 pages, LaTeX in IOP style, appeared in the Proceedings of
Strangeness'97 Conference, Santorini, April 14-18 1997, J. of Physics G23
(1997) 194
Individual and Multi Vortex Pinning in Systems with Periodic Pinning Arrays
We examine multi and individual vortex pinning in thin superconductors with
periodic pinning arrays. For multi-vortex pinning we observe peaks in the
critical current of equal magnitude at every matching field, while for
individual vortex pinning we observe a sharp drop in the critical current after
the first matching field in agreement with experiments. We examine the scaling
of the critical current at commensurate and incommensurate fields for varied
pinning strength and show that the depinning force at incommensurate fields
decreases faster than at the commensurate fields.Comment: 4 figuure
Microcanonical Treatment of Hadronizing the Quark-Gluon Plasma
We recently introduced a completely new way to study ultrarelativistic
nuclear scattering by providing a link between the string model approach and a
statistical description. A key issue is the microcanonical treatment of
hadronizing individual quark matter droplets. In this paper we describe in
detail the hadronization of these droplets according to n-body phase space, by
using methods of statistical physics, i.e. constructing Markov chains of hadron
configurations.Comment: Complete paper enclosed as postscript file (uuencoded
Self-organized criticality in the hysteresis of the Sherrington - Kirkpatrick model
We study hysteretic phenomena in random ferromagnets. We argue that the angle
dependent magnetostatic (dipolar) terms introduce frustration and long range
interactions in these systems. This makes it plausible that the Sherrington -
Kirkpatrick model may be able to capture some of the relevant physics of these
systems. We use scaling arguments, replica calculations and large scale
numerical simulations to characterize the hysteresis of the zero temperature SK
model. By constructing the distribution functions of the avalanche sizes,
magnetization jumps and local fields, we conclude that the system exhibits
self-organized criticality everywhere on the hysteresis loop.Comment: 4 pages, 4 eps figure
Finite coherent length and multi-pion correlation effects on two-pion interferometry
The effects of multi-pion correlations and finite coherent length on two-pion
interferometry are studied. It was shown that as the pion multiplicity and
coherent length become larger, the apparent radius and the apparent coherent
parameters derived from two-pion interferometry become smaller. The influence
of the coherent length on the effective temperature is discussed.Comment: 5 pages, two figure
Linking Dynamical and Thermal Models of Ultrarelativistic Nuclear Scattering
To analyse ultrarelativistic nuclear interactions, usually either dynamical
models like the string model are employed, or a thermal treatment based on
hadrons or quarks is applied. String models encounter problems due to high
string densities, thermal approaches are too simplistic considering only
average distributions, ignoring fluctuations. We propose a completely new
approach, providing a link between the two treatments, and avoiding their main
shortcomings: based on the string model, connected regions of high energy
density are identified for single events, such regions referred to as quark
matter droplets. Each individual droplet hadronizes instantaneously according
to the available n-body phase space. Due to the huge number of possible hadron
configurations, special Monte Carlo techniques have been developed to calculate
this disintegration.Comment: Complete paper enclosed as postscript file (uuencoded
The Effect of Splayed Pins on Vortex Creep and Critical Currents
We study the effects of splayed columnar pins on the vortex motion using
realistic London Langevin simulations. At low currents vortex creep is strongly
suppressed, whereas the critical current j_c is enhanced only moderately.
Splaying the pins generates an increasing energy barrier against vortex
hopping, and leads to the forced entanglement of vortices, both of which
suppress creep efficiently. On the other hand splaying enhances kink nucleation
and introduces intersecting pins, which cut off the energy barriers. Thus the
j_c enhancement is strongly parameter sensitive. We also characterize the angle
dependence of j_c, and the effect of different splaying geometries.Comment: 4 figure
Multiparticle production in the model with antishadowing
We discuss the role of absorbtion and antishadowing in particle production.
We reproduce power-like energy behavior of the mean multiplicity in the model
with antishadowing and discuss physical implications of such behavior for the
hadron structure.Comment: 11 pages, 3 figures, extended version of the talk at the XXXII
International Symposium on Multiparticle Dynamics September 7-13, 2002
Alushta, Crimea, Ukrain
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