Experimental Study of the Production of Eta Mesons and Kaons in Cu + Au Interactions at 200 GeV
The first traces of the formation of strongly interacting quark–gluon plasma (sQGP) were found in central collisions of heavy nuclei (A + A) in experiments on the RHIC collider. The quenching of hadron jets, which is seen as a reduction in the yield of particles in A + A collisions relative to their yield in proton–proton collisions, is one observable sign of sQGP formation. Asymmetrical Cu + Au collisions at 200 GeV, which are characterized by a distinct geometry of nucleus overlap that differs from the geometry in symmetrical collision systems (Au + Au or Cu + Cu), are of special interest in systematic studies of the quenching of hadron jets. The results are presented from measuring invariant transverse-momentum spectra and nuclear modification factors of mesons containing strange quarks in Cu + Au collisions at 200 GeV.