Scaling patterns of the suppression of \pi^0 yields in Au+Au collisions at \sqrt{sNN}=200 GeV: Links to the transport properties of the QGP

Roy A. Lacey, N. N. Ajitanand, J. M. Alexander, X. Gong, J. Jia, A. Taranenko, and Rui Wei

Accepted Tuesday Oct 20, 2009

Suppression measurements for neutral pions (p0) are used to investigate the predicted path length (L) and transverse momentum (pT) dependent jet quenching patterns of the hot QCD medium produced in Au+Au collisions at {sNN}=200 GeV. The observed scaling patterns show the predicted trends for jet-medium interactions dominated by radiative energy loss. They also allow simple estimates of the transport coefficient [^q] and the ratio of viscosity to entropy density h/s. These estimates indicate that the short mean free path (l) in the QCD medium leading to hydrodynamic-like flow with a small value of h/s, is also responsible for the strong suppression observed.