Fragmentation of 1.2 GeV per nucleon 139La.

Abstract

The fragmentation of 1.2 GeV per nucleon $^{139}\mathrm{La}$ nuclei has been studied. Total charge changing cross sections for H (${\mathrm{CH}}_{2}$-C), C, and Pb target nuclei, and elemental production cross sections for C and ${\mathrm{CH}}_{2}$ targets for 1\ensuremath{\le}\ensuremath{\Delta}Z\ensuremath{\le}30 have been measured. For heavy projectile fragments, the projected transverse momenta extracted are generally larger than predicted by models based on the internal momenta of nucleons in nuclei. Fits to the heavy fragment momentum distributions yield additional transverse momenta or ``bounce-off'' which range from \ensuremath{\simeq}500 to 1000 MeV/c.