scholarly journals A Description of Pseudorapidity Distributions of Charged Particles Produced in Au+Au Collisions at RHIC Energies

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Z. J. Jiang ◽  
Dongfang Xu ◽  
Yan Huang

In heavy ion collisions, charged particles come from two parts: the hot and dense matter and the leading particles. In this paper, the hot and dense matter is assumed to expand according to the hydrodynamic model including phase transition and decouples into particles via the prescription of Cooper-Frye. The leading particles are as usual supposed to have Gaussian rapidity distributions with the number equaling that of participants. The investigations of this paper show that, unlike low energy situations, the leading particles are essential in describing the pseudorapidity distributions of charged particles produced in high energy heavy ion collisions. This might be due to the different transparencies of nuclei at different energies.

2013 ◽  
Vol 22 (09) ◽  
pp. 1350069 ◽  
Author(s):  
ZHIJIN JIANG ◽  
QINGGUANG LI ◽  
GUANXIANG JIANG

By using the revised Landau hydrodynamic model and taking into account the effect of leading particles, we discuss the pseudorapidity distributions of produced charged particles in high energy heavy-ion collisions. The charged particles resulted from the freeze-out of the matter produced in collisions possess the Gaussian-like rapidity distributions. The leading particles are assumed having the rapidity distributions of the Gaussian form with the normalization constant being equal to the number of participants, which can be figured out in theory. It is found that the results from the revised Landau hydrodynamic model together with the contributions from leading particles are well consistent with the experimental data carried out by BNL-RHIC-PHOBOS Collaboration in different centrality Au + Au collisions at energies of [Formula: see text], 130 and 62.4 GeV , respectively.


1999 ◽  
Vol 77 (4) ◽  
pp. 313-318 ◽  
Author(s):  
F -H Liu ◽  
Y A Panebratsev

The pseudorapidity distribution of relativistic singly charged particles produced in high-energy heavy-ion collisions is described by the thermalized cylinder picture. The calculated results are in agreement with the experimental data of lead-induced interactions at 158A GeV/c. PACS Nos.:25.75.-q and 25.75.Dw


1997 ◽  
Vol 12 (02) ◽  
pp. 127-134 ◽  
Author(s):  
R. S. Bhalerao ◽  
S. K. Gupta

We present a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of ϕ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width (ΔM and ΔΓ) of the ϕ mesons when they are inside the dense matter formed in these collisions. We illustrate our method with the help of available preliminary data. Extracted values of ΔM and ΔΓ are significantly larger than those obtained with an earlier method. Our results are consistent with the experimentally observed pT dependence of the mass shift. Finally, we present a phenomenological relation between ΔM and ΔΓ. It provides a useful constraint on theories which predict the values of these two quantities.


2021 ◽  
Vol 136 (6) ◽  
Author(s):  
Rajendra Nath Patra ◽  
Bedangadas Mohanty ◽  
Tapan K. Nayak

AbstractThe thermodynamic properties of matter created in high-energy heavy-ion collisions have been studied in the framework of the non-extensive Tsallis statistics. The transverse momentum ($$p_\mathrm{T}$$ p T ) spectra of identified charged particles (pions, kaons, protons) and all charged particles from the available experimental data of Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) energies and Pb-Pb collisions at the Large Hadron Collider (LHC) energies are fitted by the Tsallis distribution. The fit parameters, q and T, measure the degree of deviation from an equilibrium state and the effective temperature of the thermalized system, respectively. The $$p_\mathrm{T}$$ p T  spectra are well described by the Tsallis distribution function from peripheral to central collisions for the wide range of collision energies, from $$\sqrt{s_\mathrm{NN}}$$ s NN = 7.7 GeV to 5.02 TeV. The extracted Tsallis parameters are found to be dependent on the particle species, collision energy, centrality, and fitting ranges in $$p_\mathrm{T}$$ p T . For central collisions, both q and T depend strongly on the fit ranges in $$p_\mathrm{T}$$ p T . For most of the collision energies, q remains almost constant as a function of centrality, whereas T increases from peripheral to central collisions. For a given centrality, q systematically increases as a function of collision energy, whereas T has a decreasing trend. A profile plot of q and T with respect to collision energy and centrality shows an anti-correlation between the two parameters.


2002 ◽  
Vol 17 (08) ◽  
pp. 1149-1158 ◽  
Author(s):  
A. P. BALACHANDRAN ◽  
S. DIGAL

We extend and generalize the seminal work of Brandenberger, Huang and Zhang on the formation of strings during chiral phase transitions1 and discuss the formation of Abelian and non-Abelian topological strings during such transitions in the early universe and in the high energy heavy-ion collisions. Chiral symmetry as well as deconfinement are restored in the core of these defects. Formation of a dense network of string defects is likely to play an important role in the dynamics following the chiral phase transition. We speculate that such a network can give rise to non-azimuthal distribution of transverse energy in heavy-ion collisions.


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