Event-by-Event Analysis of Proton-Induced Nuclear Multifragmentation: Determination of the Phase Transition Universality Class in a System with Extreme Finite-Size Constraints

A percolation model of nuclear fragmentation is used to interpret 10.2GeV/c p+¹⁹⁷Au multifragmentation data. Emphasis is put on finding signatures of a continuous nuclear matter phase transition in finite nuclear systems. Based on model calculations, corrections accounting for physical constraints of the fragment detection and sequential decay processes are derived. Strong circumstantial evidence for a continuous phase transition is found, and the values of two critical exponents, σ0ex0ex=0ex0ex0.5±0.1 and τ0ex0ex=0ex0ex2.35±0.05, are extracted from the data. A critical temperature of Tc0ex0ex=0ex0ex8.3±0.2MeV is found.