DAPNIA-05-32 |
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Directed and elliptic flow in 197Au+197Au at intermediate energies |
J. Lukasik, G. Auger, M.L. Begemann-Blaich, N. Bellaize, R. Bittiger, F. Bocage, B. Borderie, R. Bougault, B. Bouriquet, J.L. Charvet, A. Chbihi, R. Dayras, D. Durand, J.D. Frankland, E. Galichet, D. Gourio, D. Guinet, S. Hudan, P. Lautesse, F. Lavaud, A. Le Fèvre, R. Legrain, O. Lopez, U. Lynen, W.F.J. Müller, L. Nalpas, H. Orth, E. Plagnol, E. Rosato, A. Saija, C. Schwarz, C. Sfienti, B. Tamain, W. Trautmann, A. Trzcinski, K. Turzó, E. Vient, M. Vigilante, C. Volant, and B. Zwieglinski |
Directed and elliptic flow for the 197Au+197Au system at incident energies between 40 and 150 MeV per nucleon has been measured using the INDRA 4$pi$ multi-detector. For semi-central collisions, the elliptic flow of Z ≤ 2 particles switches from in-plane to out-of-plane enhancement at around 100 MeV per nucleon, in good agreement with the result reported by the FOPI Collaboration. The directed flow changes sign at a bombarding energy between 50 and 60 MeV per nucleon and remains negative at lower energies. The conditions for the appearance and possible origins of the observed antiflow are discussed |