Differential Transverse Flow in He(Li, C) and (p, d, He, C)(C, Ta) Collisions at 4.2, 4.5 and 10 AGeV/c Momenta

摘要

Differential transverse flow of protons and pions in HeLi and (p, d, He, C)-(C,Ta) (4.2, 4.5 and 10 AGeV/c) collisions was measured as a function of transverse momentum. The pC system is the lightest studied one, and the pTa is extremely asymmetrical system in which differential transverse flow of protons and pions have ever been detected for these particles. In agreement with predictions of a transversely moving thermal model, the strength of proton differential transverse flow is found to first increase gradually and then saturate with the increasing transverse momentum in all systems. In the whole range of transverse momentum studied pions are preferentially emitted to the opposite direction of the proton transverse flow (i.e. anti-flow) due to stronger shadowing effects. The differential flow data for both protons and pions, a dependence of the the temperatures and flow velocity b on mass numbers of projectile A_P and target A_T provide a more stringent testing ground for relativistic heavy-ion reaction theories. Detailed comparisons with predictions of relativistic transport models on the differential flow will be useful to extract more reliable information about the nuclear EOS. The data obtained from film detectors (SKM-200-GIBS - the two meter streamer chamber and PBC-500 - the propane bubble chamber), utilized at JINR. The quark gluon string and the ultrarelativistic quantum molecular dynamics models (QGSM, UrQMD) satisfactorily describe the experimental results.