Emission of Light Fragments in Heavy Ion Collisions. Does a Liquid-Gas Phase Transition Exist in Nuclear Matter

摘要

Fragments at large angle from a heavy ion collision could result from the condensation into clusters of nucleons from a hot zone of unbond nuclear matter. Analogy with the condensation of a vapour into droplets leads to predict a mass distribution of fragments of the form (dsigma/dA) proportional to Asup(-tau) with(tau) approximately = 2.33. In another proposed mechanism, nearly the whole ensemble projectile + target breaks into pieces due to the high excitation brought in by the collision. Preliminary data from the reaction Ar + Au at 44 MeV/u are examined in the light of the two descriptions. (ERA citation 10:029283)