18 research outputs found
Comparative Study of Multifragmentation of Gold Nuclei Induced by Relativistic Protons, He, and C
Multiple emission of intermediate-mass fragments has been studied for the
collisions of p, He and C on Au with the setup FASA. The mean
IMF multiplicities (for the events with at least one IMF) are saturating at the
value of for the incident energies above 6 GeV. The observed IMF
multiplicities cannot be described in a two-stage scenario, a fast cascade
followed by a statistical multifragmentation. Agreement with the measured IMF
multiplicities is obtained by introducing an intermediate phase and modifying
empirically the excitation energies and masses of the remnants.
The angular distributions and energy spectra from the p-induced collisions
are in agreement with the scenario of ``thermal'' multifragmentation of a hot
and diluted target spectator. In the case of C+Au(22.4 GeV) and
He(14.6 GeV)+Au collisions, deviations from a pure thermal break-up are
seen in the energy spectra of the emitted fragments, which are harder than
those both from model calculations and from the measured ones for p-induced
collisions. This difference is attributed to a collective flow.Comment: 33 pages 15 figures, accepted in Nucl. Phys.