Muonic atoms at RHIC

Abstract

We report the search results of muonic atoms from the STAR experiment at RHIC. The invariant mass distributions of hadron-muon pairs show peaks at the expected atom masses. Two particle correlation functions indicate the hadrons and muons that are close in phase space are emitted at the same space time point, which is a possible signature of muonic atom ionization at the beam pipe. The pion-muon correlation functions are further decomposed into two contributions, and the fraction of direct muons is obtained.