Phase Coexistence in Multifragmentation?

The charge ( Z) distributions from intermediate energy heavy-ion reactions depend upon the multiplicity n of intermediate mass fragments through a factor of the form e^-cnZ. Experimentally c starts from zero at low values of the transverse energy E_t and reaches a saturation value at high E_t. In a liquid-gas phase diagram c = 0 for the saturated vapor, while c>0 for the unsaturated vapor. It is suggested that in the c≈0 regime the source evaporates down to a sizable remnant, while for c>0 the source vaporizes completely. Percolation of finite systems and nuclear evaporation portray a behavior similar to that observed experimentally.