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Title: Rapidity Dependence of Bose-Einstein Correlations at SPS energies

Abstract

This article is devoted to results on {pi}-{pi}--Bose-Einstein correlations in central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. Rapidity as well as transverse momentum dependences of the correlation lengths will be shown for collisions at 20A, 30A, 40A, 80A, and 158A GeV beam energy. Only a weak energy dependence of the radii is observed at SPS energies. The kt-dependence of the correlation lengths as well as the single particle mt-spectra will be compared to model calculations. The rapidity dependence is analysed in a range of 2.5 units of rapidity starting at the center of mass rapidity at each beam energy. The correlation lengths measured in the longitudinally comoving system show only a weak dependence on rapidity.

Authors:
 [1]
  1. Institut fuer Kernphysik Frankfurt (IKF), Universitaet Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany)
Publication Date:
OSTI Identifier:
20800122
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 828; Journal Issue: 1; Conference: 35. internationals symposium on multiparticle dynamics; Workshop on particle correlations and femtoscopy, Kromeriz (Czech Republic), 9-17 Aug 2005; Other Information: DOI: 10.1063/1.2197457; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BOSE-EINSTEIN CONDENSATION; CENTER-OF-MASS SYSTEM; CERN SPS SYNCHROTRON; CORRELATIONS; ENERGY DEPENDENCE; GEV RANGE; LEAD 208 REACTIONS; LEAD 208 TARGET; LENGTH; PARTICLE RAPIDITY; PIONS MINUS; STATISTICAL MODELS; TRANSVERSE MOMENTUM

Citation Formats

Kniege, Stefan. Rapidity Dependence of Bose-Einstein Correlations at SPS energies. United States: N. p., 2006. Web. doi:10.1063/1.2197457.
Kniege, Stefan. Rapidity Dependence of Bose-Einstein Correlations at SPS energies. United States. doi:10.1063/1.2197457.
Kniege, Stefan. Tue . "Rapidity Dependence of Bose-Einstein Correlations at SPS energies". United States. doi:10.1063/1.2197457.
@article{osti_20800122,
title = {Rapidity Dependence of Bose-Einstein Correlations at SPS energies},
author = {Kniege, Stefan},
abstractNote = {This article is devoted to results on {pi}-{pi}--Bose-Einstein correlations in central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. Rapidity as well as transverse momentum dependences of the correlation lengths will be shown for collisions at 20A, 30A, 40A, 80A, and 158A GeV beam energy. Only a weak energy dependence of the radii is observed at SPS energies. The kt-dependence of the correlation lengths as well as the single particle mt-spectra will be compared to model calculations. The rapidity dependence is analysed in a range of 2.5 units of rapidity starting at the center of mass rapidity at each beam energy. The correlation lengths measured in the longitudinally comoving system show only a weak dependence on rapidity.},
doi = {10.1063/1.2197457},
journal = {AIP Conference Proceedings},
number = 1,
volume = 828,
place = {United States},
year = {Tue Apr 11 00:00:00 EDT 2006},
month = {Tue Apr 11 00:00:00 EDT 2006}
}
  • Electric charge correlations are studied with the Balance Function method for central Pb + Pb collisions at the CERN - SPS. The results on centrality selected Pb + Pb interactions at 40 and 158 AGeV are presented for the first time for two different rapidity intervals: The mid-rapidity region where a decrease of the width with increasing centrality of the collision is observed and the forward rapidity region where this effect vanishes. This could suggest a delayed hadronization scenario.In addition, the results from a first attempt to study the energy dependence of the Balance Function throughout the whole SPS energymore » range, will also be presented. The suitably scaled decrease of the width is approximately constant for the intermediate energies (30 to 80 AGeV) and gets stronger for the highest SPS and RHIC energies. On the other hand, both URQMD and HSD simulation results show no dependence on the collision energy.« less
  • Bose-Einstein rapidity correlations of {pi} mesons in processes multiparticle production are calculated in the model of a static source and the model of a relativistically expanding source. In both models, the normalized correlation function has a small narrow peak (relative to variations of the rapidity difference) that is due to integration with respect to transverse momenta. The effect is smaller for nuclear collisions. The two types of sources can be distinguished by the different dependences of the effect on the average rapidity of {pi}-meson pair. These properties are also reflected in the behavior of factorial moments. 4 refs.
  • In previous work, the E802 Collaboration at the BNL-AGS used negative binomial distribution (NBD) fits to charged particle multiplicity distributions from central collisions of {sup 16}O+Cu at 14.6A GeV/c to derive the two-particle short-range rapidity correlation length and strength. These turned out to be much shorter and weaker than the values for hadron collisions, which led to a simple and elegant explanation of intermittency. In the present work, a direct measurement of the two-particle correlation of identified pions in the E802/E859 magnetic spectrometer is performed in the interval 1.5{le}y{le}2.0 for central {sup 28}Si+Au collisions, both in terms of Q{sub inv}={radical}({vert_bar}{rvecmore » q}{vert_bar}{sup 2}{minus}q{sub 0}{sup 2}), where q=p{sub 2}{minus}p{sub 1}=({rvec q},q{sub 0}), and also in terms of {vert_bar}{eta}{sub 2}{minus}{eta}{sub 1}{vert_bar} and {vert_bar}y{sub 2}{minus}y{sub 1}{vert_bar}, where p,{eta}, and {ital y} are the four-momentum, pseudorapidity, and rapidity of the pions. It is demonstrated that the two-pion correlation in rapidity (and pseudorapidity) is entirely due to the Bose-Einstein interference. The directly measured correlation length in both {eta} and {ital y} is {xi}=0.19{plus_minus}0.03 for two {pi}{sup {minus}}, with strength R(0,0){approximately}1{percent}, in agreement with the previous E802 indirect measurements derived from the NBD analysis of intermittency. {copyright} {ital 1997} {ital The American Physical Society}« less