Has the QCD critical point been signaled by observations at the BNL relativistic heavy ion collider?

Roy A Lacey; N N Ajitanand; J M Alexander; P Chung; W G Holzmann; M Issah; A Taranenko; P Danielewicz; Horst Stöcker

doi:10.1103/PhysRevLett.98.092301

Has the QCD critical point been signaled by observations at the BNL relativistic heavy ion collider?

Phys Rev Lett. 2007 Mar 2;98(9):092301. doi: 10.1103/PhysRevLett.98.092301. Epub 2007 Mar 2.

Authors

Roy A Lacey¹, N N Ajitanand, J M Alexander, P Chung, W G Holzmann, M Issah, A Taranenko, P Danielewicz, Horst Stöcker

Affiliation

¹ Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, USA.

PMID: 17359152
DOI: 10.1103/PhysRevLett.98.092301

Abstract

The shear viscosity to entropy ratio (eta/s) is estimated for the hot and dense QCD matter created in Au+Au collisions at BNL Relativistic Heavy Ion Collider (square root[s_{NN}]=200 GeV). A very low value is found; eta/s approximately 0.1, which is close to the conjectured lower bound (1/4pi). It is argued that such a low value is indicative of thermodynamic trajectories for the decaying matter which lie close to the QCD critical end point.