Widths of the balance function for charged kaon pairs from Au + Au at GeV and p + p at GeV at RHIC

Abstract

The balance function is based on the principle that charge is locally conserved when particles are pair produced. Balance functions have been measured for identified charged pion pairs, and identified charged kaon pairs in Au+Au collisions at GeV and p+p collisions at GeV at the relativistic heavy ion collider using STAR. Balance functions for all observed particles from Au+Au scale smoothly with centrality to the p+p value. Balance functions for pions are narrower in central collisions than in peripheral collisions consistent with trends predicted by models incorporating late hadronization. Balance functions for kaon pairs also represent a strangeness balance. Balance functions for kaons are narrower than those for pion pairs and show less dependence on centrality.