979 research outputs found
Stable Bose-Einstein correlations
The shape of Bose-Einstein (or HBT) correlation functions is determined for
the case when particles are emitted from a stable source, obtained after
convolutions of large number of elementary random processes. The two-particle
correlation function is shown to have a {\it stretched exponential} shape,
characterized by the L\'evy index of stability and the
scale parameter . The normal, Gaussian shape corresponds to a particular
case, when is selected. The asymmetry parameter of the stable
source, is shown to be proportional to the angle, measured by the
normalized three-particle cumulant correlations.Comment: 7 pages, no figures, invited talk of T. Csorgo at the 2nd Warsaw
Meeting on Particle Correlations and Resonances in HIC, see
http://hirg.if.pw.edu.pl/en/meeting/oct2003/talks/csorgo/Csorgo.pp
Bose-Einstein or HBT correlations and the anomalous dimension of QCD
Bose-Einstein (or HBT) correlation functions are evaluated for the fractal
structure of QCD jets. These correlation functions have a stretched exponential
(or Levy-stable) form. The anomalous dimension of QCD determines the Levy index
of stability, thus the running coupling constant of QCD becomes measurable with
the help of two-particle Bose-Einstein correlation functions. These
considerations are tested on NA22 and UA1 two-pion correlation data.Comment: 8 pages, 5 figures, presented by T. Csorgo at the XXXIV International
Symposium on Multiparticle Dynamics, Sonoma County, California, USA, July
2004, to appear in Acta Physica Polonica
Bose-Einstein or HBT correlation signature of a second order QCD phase transition
For particles emerging from a second order QCD phase transition, we show that
a recently introduced shape parameter of the Bose-Einstein correlation
function, the Levy index of stability equals to the correlation exponent - one
of the critical exponents that characterize the behavior of the matter in the
vicinity of the second order phase transition point. Hence the shape of the
Bose-Einstein / HBT correlation functions, when measured as a function of
bombarding energy and centrality in various heavy ion reactions, can be
utilized to locate experimentally the second order phase transition and the
critical end point of the first order phase transition line in QCD.Comment: 8 pages, talk given by T. Csorgo at the Workshop on Particle
Correlations and Femtoscopy 2005, Kromeriz, Czech Republic, August 200
A Bose-Einstein Model of Particle Multiplicity Distributions
A model of particle production is developed based on a parallel with a theory
of Bose-Einstein condensation and similarities with other critical phenomena
such as critical opalescence. The role of a power law critical exponent tau and
Levy index alpha are studied. Various features of this model are developed and
compared with other commonly used models of particle production which are shown
to differ by having different values for tau, alpha. While void scaling is a
feature of this model, hierarchical structure is not a general property of it.
The value of the exponent tau=2 is a transition point associated with void and
hierarchical scaling features. An exponent gamma is introduced to describe
enhanced fluctuations near a critical point. Experimentally determined
properties of the void scaling function can be used to determine tau.Comment: Accepted for publication in Nucl. Phys.
Analytic Solution of the Pion-Laser Model
Brooding over bosons, wave packets and Bose - Einstein correlations, we find
that a generalization of the pion-laser model for the case of overlapping
wave-packets is analytically solvable with complete n-particle symmetrization.
The effective radius parameter of the two-particle correlation function is
reduced for low values and enlargened for high values of the mean momentum in
the rare gas limiting case, as compared to the case when multi-particle
symmetrization effects are neglected.
These results explicitly depend on the multiplicity, providing a theoretical
basis for event-by-event analysis of high energy heavy ion reactions.Comment: LaTeX, ReVTeX 3.1, 7 pages, uses 1 eps figure and epsfig.sty
(shortened version
Model independent shape analysis of correlations in 1, 2 or 3 dimensions
A generic, model-independent method for the analysis of the two-particle
short-range correlations is presented, that can be utilized to describe e.g.
Bose-Einstein (HBT or GGLP), statistical, dynamical or other short-range
correlation functions. The method is based on a data-motivated choice for the
zero-th order approximation for the shape of the correlation function, and on a
systematic determination of the correction terms with the help of complete
orthonormal set of functions. The Edgeworth expansion is obtained for
approximately Gaussian, the Laguerre expansion for approximately exponential
correlation functions. Multi-dimensional expansions are also introduced and
discussed.Comment: Latex, 15 pages, uses epsfig.sty elsart.sty, misprints correcte
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