## Towards A Universal Law of Particle Production in Heavy-Ion Collisions    [PDF]

Aditya Nath Mishra, Rakesh Mazumder, Raghunath Sahoo
In the frame work of a nuclear overlap model, we estimate the number of nucleon and quark participants in nucleus-nucleus collisions. At RHIC and LHC energies, the number of nucleons-normalized charged particle and transverse energy density in pseudorapidity, which shows a monotonic rise with centrality, turns out to be an almost centrality independent scaling behavior when normalized to the number of participant quarks. This indicates partonic activities both in RHIC and LHC heavy-ion collisions. We study the charged particle and transverse energy production mechanism from AGS, SPS, RHIC to LHC energies in the framework of nucleon and quark participants as well. A universal function which is a combination of logarithmic and power-law, describes the charged particle and transverse energy production both at nucleon and quark participant level quite well for the whole range of collision energy under discussion. A detailed energy dependent production mechanisms are discussed both for nucleonic and partonic level. We give the predictions for $\frac{dN_{\rm{ch}}}{d\eta}$, $\frac{dE_{\rm{T}}}{d\eta}$ and the barometric observable, $\frac{E_{\rm{T}}}{N_{\rm{ch}}}$ for Pb+Pb collisions at $\sqrt{s_{\rm{NN}}}=5.5$ TeV. A universal law of particle production from elementary to heavy-ion collisions is proposed.
View original: http://arxiv.org/abs/1304.2113