Clustering in light nuclei and their effects on fusion and pre – equilibrium processes.

¹ Laboratori Nazionali di Legnaro, 35020 Legnaro (Pd), Italy
² University of Padova, Dep. of Physics and Astronomy, 35100 Padova, Italy
³ INFN Padova, 35100 Padova, Italy
⁴ KU Leuven, Dep. of Phys. and Astron. Instituut voor Kern- en Stralingsfysica, 3001 Leuven, Belgium
⁵ Science and Art Faculty, Phys. Dep., Nevsehir Haci Bektas Veli Univ., Nevsehir, Turkey
⁶ INFN Ferrara and University of Ferrara, Dep. of Chemistry, Ferrara, Italy
⁷ INFN Bologna and University of Bologna, Dep. of Physics and Astronomy, Bologna, Italy
⁸ INFN Firenze and University of Firenze, Dep. of Physics and Astronomy, Firenze, Italy
⁹ INFN Firenze, Firenze, Italy
¹⁰ GANIL, Caen, France
¹¹ INFN Napoli and University of Napoli, Dep. of Physics and Astronomy, Napoli, Italy
¹² INFN Milano and University of Milano, Dep. of Physics and Astronomy, Milano, Italy
¹³ Institute of Nuclear Physics, Polish Academy of Sciences Krakow, Poland
¹⁴ Laboratori Nazionali dl Sud, Catania, Italy
¹⁵ Tohoku University, Sendai, Japan
¹⁶ University of Pavia, Dep. of Physics, Pavia, Italy

^* e-mail: fabiana.gramegna@lnl.infn.it
^** e-mail: magda.cicerchia@lnl.infn.it

Published online: 22 November 2017

Abstract

The study of nuclear cluster states bound by valence neutrons is a field of recent large interest. In particular, it is important to study the pre-formation of α-clusters in α-conjugate nuclei and the dynamical condensation of clusters during nuclear reactions [1–5]. The NUCL–EX collaboration has recently initiated an experimental campaign of exclusive measurements of fusion–evaporation reactions with light nuclei as interacting partners. In collisions involving light systems, the low expected multiplicity of fragments increases the probability of achieving a quasi-complete reconstruction of the event. In particular the formation and decay modes of an excited ²⁴Mg system have been studied through two different reactions, ¹²C (95 MeV)+ ¹²C and ¹⁴N (80.7 MeV)+ ¹⁰B, which have been used to produce fused systems with nearly the same mass and excitation energy (~60 MeV). In particular, even the de-excitation of the Hoyle state in ¹²C have been studied, both in peripheral (projectiles de-excitation) and in central collisions (six α-particles channel). Moreover, a research campaign studying pre-equilibrium emission of light charged particles and cluster properties of light and medium-mass nuclei has been carried out. For this purpose, a comparative study of the three nuclear systems ¹⁸O+²⁸Si, ¹⁶O+³⁰Si and ¹⁹F+²⁷Al has been recently studied using the GARFIELD+RCo 4π setup [6]. The experimental data are compared with the predictions of simulated events generated with the statistical models (GEMINI⁺⁺ and HFl) and through dynamical models like Stochastic Mean Field (SMF) and Antisymmetrized Molecular Dynamics (AMD) and filtered with a software replica of our apparatus in order to take into account the experimental conditions.