The charge distribution of the intermediate mass fragments produced in p (8.1 GeV) + Au collisions is analyzed in the framework of the statistical multifragmentation model with the critical temperature for the nuclear liquidgas phase transition T c as a free parameter. It is found that T c = 20±3 MeV (90% CL).

Multiple emission of intermediate-mass fragments has been studied for the collisions of p, 4 He and 12 C on Au with the 4π setup FASA. The mean IMF multiplicities (for the events with at least one IMF) are saturating at the value of 2.2 ± 0.2 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 12 C+Au(22.4 GeV) and 4 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.

Critical temperature T c for the nuclear liquid-gas phase transition is estimated both from the multifragmentation and fission data. In the first case, the critical temperature is obtained by analysis of the IMF yields in p(8.1 GeV) +Au collisions within the statistical model of multifragmentation (SMM). In the second case, the experimental fission probability for excited 188 Os is compared with the calculated one with T c as a free parameter. It is concluded for both cases that the critical temperature is higher than 16 MeV.

Multiple emission of intermediate-mass fragments has been studied for the collisions p + Au at 2.16, 3.6 and 8.1 GeV with the FASA setup. The mean IMF multiplicities for events with at least one IMF are equal to 1.7, 1.9 and 2.1 (±0.2) respectively. The multiplicity, charge distributions and kinetic energy spectra of IMF are described in the framework of a intranuclear cascade model followed by the statistical multifragmentation model. However, between the two parts of the calculation the excitation energies and the residual masses and charges are modified to take into account the losses during expansion. The results support a scenario of true thermal multifragmentation of a hot and expanded target spectator.

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