Experimental data concerning isospin transport phenomena for the systems at 35 MeV/nucleon are presented. Data have been collected with four FAZIA blocks; this data set is the same analyzed in S. Piantelli et al., Phys. Rev. C 101, 034613 (2020). The isotopic composition of the QuasiProjectile residue (up to around 25) and of its decay products in the two reactions are compared, finding a neutron enrichment when the target is . The isotopic composition of the emitted light charged particles (LCP) and intermediate mass fragments (IMF) was also investigated in different windows of velocity. The obtained results have been compared with the prediction of the transport model AMD followed by the statistical code GEMINI (used as an afterburner), with different recipes for the density dependence of the symmetry energy term in the nuclear equation of state. A weak indication in favor of a stiff symmetry energy emerges when the fragments emitted at midvelocity are examined.
The neutron-proton (n-p) equilibration process in at 35 MeV/nucleon bombarding energy is experimentally estimated by means of the isospin transport ratio. Experimental data are collected with a subset of the FAZIA telescope array, which permits us to determine the and of detected fragments. For the first time, the quasiprojectile (QP) evaporative channel is compared with the QP breakup one in a homogeneous and consistent way, pointing to comparable n-p equilibration, which suggests a close interaction time between projectile and target independently of the exit channel. Moreover, in the QP evaporative channel n-p equilibration is compared with the prediction of the antisymmetrized molecular dynamics model coupled with the Gemini statistical model as an afterburner, showing a higher probability of proton and neutron transfers in the simulation with respect to the experimental data.
Starting from experimental studies on alpha-clustering in excited self-conjugate nuclei (from O to Si), temperature and density conditions for such a clustering are determined. Measured temperatures have been found in the range of 5.5–6.0 MeV, whereas density values of 0.3–0.4 times the saturation density are deduced, i.e., 0.046 to 0.062 fm. Such a density domain is also predicted by constrained self-consistent mean field calculations. These results constitute a benchmark for alpha clustering from self-conjugate nuclei in relation to descriptions of stellar evolution and supernovae.
Correlations and clustering are of great importance in the study of the Nuclear Equation of State. Information on these items/aspects can be obtained using heavy-ion reactions which are described by dynamical theories. We propose a dataset that will be useful for improving the description of light cluster production in transport model approaches. The dataset combines published and new data and is presented in a form that allows direct comparison of the experiment with theoretical predictions. The dataset is ranging in bombarding energy from 32 to 1930 A MeV. In constructing this dataset, we put in evidence the existence of a change in the light cluster production mechanism that corresponds to a peak in deuteron production.