Fractional Energy Loss and Centrality Scaling

Abstract

The phenomenon of centrality scaling in the high-\pt spectra of ${\pi }^0$ produced in Au-Au collisions at $\sqrt{s}=200$ GeV is examined in the framework of relating fractional energy loss to fractional centrality increase. A new scaling behavior is found where the scaling variable is given a power-law dependence on $N_{\mathrm{part}}$. The exponent $\gamma$ specifies the fractional proportionality relationship between energy loss and centrality, and is a phenomenologically determined number that characterizes the nuclear suppression effect. The implication on the parton energy loss in the context of recombination is discussed.

Comments: 4 pages in RevTeX