High-precision momentum measurements of projectile fragments in Sn+Sn collisions at 1·A GeV

Abstract

Production cross-sections and longitudinal velocity distributions of the projectilelike residues produced in peripheral and mid-peripheral reactions 112Sn + 112Sn and 124Sn + 124Sn both at an incident beam energy of 1 A GeV were measured with the high-resolution magnetic spectrometer, the Fragment Separator of GSI. For both reactions the characteristics of the velocity distributions and nuclide production cross-sections were determined for residues with nuclear charge Z 10. A comparison of the results of the two reactions is presented and the results are studied in the frame of dynamical transport calculations coupled with a statistical multifragmentation code. In mid-peripheral collisions the simulations show that the rapidly expanding participant zone interacts with the spectator matter giving substantial increase on the longitudinal velocity that shows sensitivity to the nucleon-nucleon cross section and to the momentum dependence of the nuclear mean eld.