Signatures of critical behavior in the multifragmentation of nuclei with chargeZ=12−15and theN/Zdependence

Abstract

We have investigated the disassembly of light nuclear systems with charge $12\text{\ensuremath{-}}15$ to extract the power-law parameters of the fragmenting nuclear system. Excited nuclei were produced in semiperipheral reactions $^{28}\mathrm{Si}$+$^{112,124}\mathrm{Sn}$ at 30 and 50 MeV/nucleon and the residual cold fragments were detected by the multidetector array for charged particles FAUST. We have studied the power-law parameter \ensuremath{\tau} as a function of the excitation energy of quasiprojectiles. We observe a systematic occurrence of the minimum of \ensuremath{\tau} with respect to the excitation energy accompanied by the maximum of the second moment of the charge distribution in the same region of excitation energy. The main features observed in the characteristics of mass and charge distributions for multifragmentation of heavier systems, such as power-law behavior of charge distribution, are thus observed also for very light systems. Moreover, behavior of the charge distribution with respect to the $N/Z$ degree of freedom has been shown.