RAPIDITY DEPENDENCE OF CHARGE FLUCTUATIONS AND CORRELATIONS IN HADRONIC AND NUCLEAR COLLISIONS

2007 ◽  
Vol 22 (16n17) ◽  
pp. 2909-2919 ◽  
Author(s):  
AOQI FENG ◽  
NA LI ◽  
JINGHUA FU ◽  
YUANFANG WU

Size and position of rapidity window dependence of charge fluctuations and correlations are studied by PYTHIA and RQMD models for hadron–hadron and nucleus–nucleus collisions respectively. The results show that all the measures for charge fluctuations and correlations depend on the size of central rapidity windows and most of them depend on the position of the rapidity windows, which is not expected. Only charge balance function in hadron–hadron collisions is independent of the position of rapidity window, i.e. boost-invariant, in consistent with corresponding experimental data, while charge fluctuations measured by D(Q) is not boost-invariant in contrast to the experimental data. The measures for three kind of charge correlations (R++, R--, R+-) show a good account for the behavior of charge correlations and global charge conservation in longitudinal phase space in both PYTHIA and RQMD.

2007 ◽  
Vol 16 (10) ◽  
pp. 3355-3362
Author(s):  
DU JIAXIN ◽  
LI NA ◽  
LIU LIANSHOU

A Monte Carlo study on the charge balance function in high energy hadron-hadron and relativistic heavy ion collisions are carried out using the Monte Carlo generators PYTHIA and AMPT, respectively. A strong dependence of the width of balance function on multiplicity is found in both cases. Using the mean parton-freeze-out time of a heavy-ion-collision event as the characteristic hadronization time for the event, it is found that for a fixed multiplicity interval the width of balance function is consistent with being independent of hadronization time.


2011 ◽  
Vol 85 (6) ◽  
pp. 923-927 ◽  
Author(s):  
Na Li ◽  
Zhiming Li ◽  
Lianshou Liu ◽  
Yuanfang Wu

2014 ◽  
Vol 23 (08) ◽  
pp. 1450036 ◽  
Author(s):  
Ying-Hua Pan ◽  
Wei-Ning Zhang

Experiment and lattice simulation show that the quark–gluon plasma (QGP) system displays strong interaction between constituents at temperature a few times the critical temperature Tc. This QGP picture can be explained by assuming that the QGP matter above Tc is rich in different kinds of bound states, namely resonance-like QGP (RQGP). The chemical composition of the QGP system produced in ultra-relativistic heavy-ion collisions can be investigated through a general charge balance function which describes two-wave quark production during expansion afterward. In this paper, we investigate the signals of this RQGP through general charge balance functions. We find that the quasiparticles in QGP contribute a little to the balance functions because of their heavy masses. The balance functions reduce to the situation discussed before where only one-wave charge production is involved if only the quasiparticles in QGP are considered. However, the baryonic bound states in QGP have a significant effect on the balance function [Formula: see text], causing a dip in the [Formula: see text] balance function at small Δy. The existence of the binary and baryonic bound states amplify the negative dip of the balance function BpK-(Δy) at Δy ∽ 1.


2008 ◽  
Vol 17 (04) ◽  
pp. 707-713 ◽  
Author(s):  
N. AHMAD ◽  
A. SHAKEEL ◽  
M. M. KHAN ◽  
A. KAMAL ◽  
A. R. KHAN

Analysis of the experimental data on 14.5A GeV/c 28 Si -nucleus interactions yields a linear relationship between ln 〈nq〉 and ln 〈n〉, for q = 2, 3, 4 and 5 and also between [Formula: see text] and ln 〈n〉, where n is the multiplicity in a given psedorapiodity bin. Generalized dimensions, Dq are also determined from the slopes of the linear variations of ln 〈nq〉 with ln 〈n〉. These results are supported reasonably well by the predictions of the Lund Model of nuclear collisions, FRITIOF.


2002 ◽  
Vol 543 (3-4) ◽  
pp. 208-216 ◽  
Author(s):  
K.J. Eskola ◽  
K. Kajantie ◽  
P.V. Ruuskanen ◽  
K. Tuominen

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