Tomographic Studies of the sQGP at RHIC

摘要

Azimuthal correlation functions are used to study jet and di-jet properties as a function of centrality in Au+Au collisions at (s_(NN))~(1/2) = 200 GeV. Utilizing a novel technique to decompose the correlation function into a (di-)jet and an underlying event, the jet-pair distribution is extracted and compared to similar results for d+Au collisions obtained at the same collision energy. A striking similarity is observed between the widths and associated yields of the (di-)jet distributions for d+Au and peripheral Au+Au collisions. By contrast, the distributions for mid-central Au+Au collisions indicate an increase in the di-jet yield with centrality, and a very broad away-side jet having a possible minimum at ΔΦ ≈ π. These features point to significant medium induced modification to the away-side jet and are compatible with recent predictions of jet-induced "conical flow".