Possible effects of clustering structure in the competition between fast emission processes and compound nucleus decay

Abstract

The attention to nuclear clustering has been renewed due to the study of weakly bound nuclei at the drip lines. In particular, clustering structural properties in medium-mass systems have been studied by looking at the competition between the evaporation and pre-equilibrium particle emission in central collisions. Although for light nuclei at an excitation energy close to the particle separation value there are experimental evidence of such structure effects, this is still not the case for heavier systems since the determination of pre-formed clusters within nuclear matter is less obvious. Two systems, leading to the same ⁸¹Rb* compound nucleus, have been studied at the same beam velocity 16 AMeV: ¹⁶O + ⁶⁵Cu and ¹⁹F + ⁶²Ni. The experiment has been performed using the GARFIELD + RCo detection system installed at the Legnaro National Laboratories.Light charged particles energy distributions and multiplicities have been compared with different statistical and dynamical model calculations. From the first comparison between the two systems a difference in the fast ? -decay channel has been evidenced, which can be related to the difference in the projectile structure. Recent data analysis results and comparisons with model calculations are presented in this contribution.