Eur. Phys. J. A (2014) 50: 31
https://doi.org/10.1140/epja/i2014-14031-0

Regular Article - Experimental Physics

Heavy-ion collisions: Direct and indirect probes of the density and temperature dependence of E_sym

¹ National Superconducting Cyclotron Laboratory, Michigan State University, 48824, East Lansing, Michigan, USA
² Department of Chemistry, Michigan State University, 48824, East Lansing, Michigan, USA
³ Cyclotron Institute, Texas A&M University, 77843, College Station, Texas, USA
⁴ Chemistry Department, Texas A&M University, 77843, College Station, Texas, USA

^* e-mail: kohley@nscl.msu.edu

Received: 2 August 2013
Revised: 16 October 2013
Accepted: 8 November 2013
Published online: 26 February 2014

Abstract

Heavy-ion collisions provide a versatile terrestrial probe of the nuclear equation of state through the formation of nuclear matter at a wide variety of temperatures, densities, and pressures. Direct and indirect approaches for constraining the density dependence of the symmetry energy using heavy-ion collisions have been developed. The direct approach relies on scaling methods which attempt to connect isotopic fragment distributions to the symmetry energy. Using the indirect approach constraints on the equation of state are extracted from comparison of experimental results and theoretical transport calculations which utilize effective nucleon-nucleon interactions. Besides exploring the density dependence of the equation of state, heavy-ion collisions are simultaneously probing different temperature gradients of nuclear matter allowing for the temperature dependence of the symmetry energy to be examined. The current progress and open questions related to constraining the density and temperature dependence of the symmetry energy with heavy-ion collisions are discussed in this paper.