A comprehensive description of multiple observables in heavy-ion collisions at SPS

Abstract

Combining and expanding on work from previous publications, a model for the evolution of ultrarelativistic heavy-ion collisions at the CERN SPS for 158 AGeV beam energy is presented. Based on the assumption of thermalization and a parametrization of the space-time expansion of the produced matter, this model is able to describe a large set of observables including hadronic momentum spectra, correlations and abundancies, the emission of real photons, dilepton radiation and the suppression pattern of charmonia. Each of these obervables provides unique capabilities to study the reaction dynamics and taken together they form a strong and consistent picture of the evolving system. Based on the emission of hard photons, we argue that a strongly interacting, hot and dense system with temperatures above 250 MeV has to be created early in the reaction. Such a system is bound to be different from hadronic matter and likely to be a quark-gluon plasma, and we find that this assumption is in line with the subsequent evolution of the system that is reflected in other observables.

HighpThadrons as probes of the central region of Au-Au collisions atSNN=200Renk1 2006Phys. Rev. CSelf Cite36070View full textAdd to dashboardCite

“…To describe the medium we use a parametrization of the spacetime evolution which is based on a simultaneous fit to hadronic spectra and Hanbury-Brown-Twiss correlation radii at low p T [21] (see also [22] for details of the formalism) and which has been used to successfully predict the emission of thermal photons [23,24]. We have used the same description to study the excitation of Mach cones by high p T jets [10] and the sensitivity of the nuclear modification factor…”

Rapidity Dependence of HBT Correlation Radii in Non-Boost Invariant Models

“…Since the relation between proper time as measured in the co-moving frame and lab time is determined by the rapidity at a given time, the resulting integral is in general non-trivial and solved numerically (see [6] for details). R 0 is determined in overlap calculations using Glauber theory, the initial size of the rapidity interval occupied by the fireball matter.…”

“…The model allows for the possibility of accelerated longitudinal expansion which in general implies η = η s [6]. This mismatch between spacetime and momentum rapidity can be parametrized as a local ∆η = η − η s which is a function of τ and η s .…”

Photonic measurements of the longitudinal expansion dynamics in relativistic heavy-ion collisions

“…The rapidity distribution is assumed to grow from some initial width 2 · y 0 to a final width 2 · y F . This determines the extension of the emitting source in spacetime rapidity η s [8,14].…”