Λ flow and Λ-P correlation in Au + Au collisions at AGS energies

Transverse and radial flow measurements are presented for Λ hyperons along with Λ-P correlations from Au + Au collisions at AGS energies. The flow measurements are compared with those of co-produced protons. The measurements indicate that Λ hyperons flow consistently in the same direction as protons but with a smaller magnitude for all beam energies. Comparisons with RQMD calculations show that the experimentally determined Λ sideward flow is consistently larger compared with the calculated value obtained from scattering processes only. The experimental transverse flow ratio Λ/P is consistent with predictions ( 2/3) of the quark counting rule at 2 A GeV but is found to decrease with increasing beam energy. These observations may be related to the detailed features of the Λ-nucleon potential for the nuclear densities produced. At 6 A GeV, Λp correlation functions are observed to be essentially flat (within statistical uncertainty), indicating little or no correlation between Λs and co-produced protons. This suggests that Λs may have a spacetime emission pattern which is different from that for protons. Further evidence from radial flow measurements also indicates that 6 A GeV Λ hyperons (at mid-rapidity) do not share the same emitting source characteristics as co-produced protons.