Relation of hard and total cross sections to centrality

Abstract

We compare the fractions of the hard and geometric cross sections as a function of impact parameter. For a given definition of central collisions, we calculate the corresponding impact parameter and the fraction of the hard cross section contained within this cut. We use charm quark production as a definite example.

Comments: 10 pages LaTeX, 6 .eps figures, uses hip-artc.sty and hip-100a.sty, style files provided