233 research outputs found
Analyses of two and three pion Bose-Einstein Correlations using Coulomb wave functions
Using effective formulas we analyze the Bose-Einstein correlations (BEC) data
corrected for Coulomb interactions provided by STAR Collaboration and the
quasi-corrected data (raw data with acceptance correction etc) on 2\pi and 3\pi
BEC by using Coulomb wave function with coherence parameter included. The
corresponding magnitudes of the interaction regions turn out to be almost the
same: R_{Coul}(2\pi) \simeq \frac 32R_{Coul}(3\pi). R_{Coul} means the size of
interaction region obtained in terms of Coulomb wave function. This approximate
relation is also confirmed by the core-halo model. Moreover, the genuine 3rd
order term of BEC has also been investigated in this framework and its
magnitude has been estimated both in the fully corrected data and in the
quasi-corrected data.Comment: 12 pages, 5 figure
Third order Bose-Einstein correlations by means of Coulomb wave function revisited
In previous works, in order to include correction by the Coulomb wave
function in Bose-Einstein correlations (BEC), the two-body Coulomb scattering
wave functions have been utilized in the formulation of three-body BEC.
However, the three-body Coulomb scattering wave function, which satisfies
approximately the three-body Coulomb scattering Schrodinger equation, cannot be
written by the product of the two-body scattering wave functions. Therefore, we
reformulate the three-body BEC, and reanalyze the data. A set of reasonable
parameters is obtained.Comment: 9 pages, 5 figure
Possible formulations for three-charged particles correlations in terms of Coulomb wave functions
The recent data for Bose-Einstein Correlations (BEC) of three-charged
particles obtained by NA44 Collaboration have been analysed using theoretical
formula with Coulomb wave functions. It has been recently proposed by Alt et
al. It turns out that there are discrepancies between these data and the
respective theoretical values. To resolve this problem we seek a possibly
modified theoretical formulation of this problem by introducing the degree of
coherence for the exchange effect due to the BEC between two-identical bosons.
As a result we obtain a modified formulation for the BEC of three-charged
particles showing good agreement with the data. Moreover, we investigate
physical connection between our modified formulation and the core-halo model
proposed by Csorgo et al. Our study indicates that the interaction region
estimated by the BEC of three-charged particles in the S + Pb collisions at 200
GeV/c per nucleon is equal to about 1.5 fm~1.8 fm.Comment: 15 pages, 7 postscript figures, with addendu
Improved Coulomb Correction Formulae for Bose-Einstein Correlations
We present improved Coulomb correction formulae for Bose-Einstein
correlations including also exchange term and use them to calculate appropriate
correction factors for several source functions. It is found that Coulomb
correction to the exchange function in the Bose-Einstein correlations cannot be
neglected.Comment: LaTex file, 8 pages, hard copies of 6 (multiple) figures available on
request to [email protected] or [email protected]
Local Thermalization in the d + Au System
The extent of a locally equilibrated parton plasma in d + Au collisions at
sqrt(s_NN) = 200 GeV is investigated as a function of collision centrality in a
nonequilibrium-statistical framework. Based on a three-sources model,
analytical solutions of a relativistic diffusion equation are in precise
agreement with recent data for charged-particle pseudorapidity distributions.
The moving midrapidity source indicates the size of the local thermal
equilibrium region after hadronization. In central d + Au collisions it
contains about 19% of the produced particles, and its relative importance rises
with decreasing centrality.Comment: 9 pages, 3 figures; new tabl
Analysis of residual spectra and the monopole spectrum for 3 K blackbody radiation by means of non-extensive thermostatistics
We analyze residual spectra of 3 K blackbody radiation (CMB) using
non-extensive thermostatistics with a parameter q-1. The limits of
|q-1|<1.2x10^{-5} and the temperature fluctuation |delta T|<(1.6-4.3)x10^{-5}
are smaller than those by Tsallis et al. Moreover, analyzing the monopole
spectrum by a formula including the chemical potential mu, we obtain the limits
|q-1|<2.3x10^{-5} and |mu|<1.6x10^{-4}. |q-1| is comparable with the
Sunyaev-Zeldovich effect y
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