Study of the in medium cross-section and of the clustering process by means of the Bayesian technique applied to a nuclear reaction at Fermi energy

A Bayesian analysis aimed at tuning two parameters of the AMD model, one of them related to the in medium nucleon nucleon cross-section and the other to the clustering, has been performed. Experimental data collected with four blocks of the FAZIA setup have been compared with simulated data built with different values of the investigated parameters

Performance of the AMD model for the low-energy reaction 18O+12C at 16.7 MeV/nucleon

This study investigates the performance of the antisymmetrized molecular dynamics (AMD) transport model in simulating the low-energy nuclear reactions 18O+12C at 16.7 MeV/nucleon. The experimental data, gathered using the GARFIELD+RCo detector at Laboratori Nazionali di Legnaro, are compared with the AMD model coupled with the GEMINI++ decay code. The study found that the model accurately predicts the behaviour of fragments with Z ≥ 10, while discrepancies were pointed out in the production of fragments with 4 <Z<10

Isotopic composition of quasi-projectile fission fragments for the systems 40,48Ca + 40,48Ca at 35 AMeV

In this paper, preliminary results for the reactions 40,48Ca + 40,48Ca at 35MeV/u in the framework of the FAZIASYM experiment are discussed. FAZIASYM experiment was performed at the LNS cyclotron with 4 blocks of the FAZIA apparatus. We will focus on the quasi-projectile fission events. After a brief overview on the various analysis steps, we will show some results on the isospin content of both fission-like fragments, comparing the cases of the two extreme n-rich and n-deficient systems also by exploiting a recently introduced order variable

Isospin diffusion from 40,48Ca + 40,48Ca experimental data at Fermi energies: Direct comparisons with transport model calculations

This article presents an investigation of isospin equilibration in cross-bombarding 40,48 Ca + 40,48 Ca reactions at 35 MeV/nucleon, by comparing experimental data with filtered transport model calculations. Isospin diffusion is studied using the evolution of the isospin transport ratio with centrality. The asymmetry parameter δ = (N − Z )/A of the quasiprojectile (QP) residue is used as isospin-sensitive observable, while a recent method for impact parameter reconstruction is used for centrality sorting. A benchmark of global observables is proposed to assess the relevance of the antisymmetrized molecular dynamics (AMD) model, coupled to GEMINI++, in the study of dissipative collisions. Our results demonstrate the importance of considering cluster formation to reproduce observables used for isospin transport and centrality studies. Within the AMD model, we prove the applicability of the impact parameter reconstruction method, enabling a direct comparison to the experimental data for the investigation of isospin diffusion. For both, we evidence a tendency to isospin equilibration with an impact parameter decreasing from 9 to 3 fm, while the full equilibration is not reached. A weak sensitivity to the stiffness of the equation of state employed in the model is also observed, with a better reproduction of the experimental trend for the neutron-rich reactions.Departamento de Física Aplicad

Deviations from Hauser-Feshbach behaviour in evaporation chains in light heavy-ion collisions

In the framework of the INFN NUCL-Ex experiment, we extended the investigation on the decay of light nuclei at excitation energies above particle emission thresholds, by performing exclusive fusion-evaporation measurements. The 16O + 12C reaction was investigated at three different bombarding energies, 90.5, 110 and 130 MeV. For complete fusion, such reactions lead to a fused 28Si∗ compound nucleus respectively at 55, 63 and 72 MeV excitation energy. By investigating this autoconjugate system we put into evidence the role of non-statistical effects, also clearly observed in our previous studies in lighter systems

Looking for non-statistical effects in the decay of 36,37Ar∗: First results

The system 24Mg+12,13C at an energy of 162 and 142 MeV respectively has been investigated with the GARFIELD and RingCounter detectors at LNL. Thanks to their large coverage and their good identification capability, it is possible to obtain a clean data set where the total charge of exited 36,37Ar∗ compound nucleus is detected. The experimental data are compared with simulated events using the standard GEMINI++ statistical code

Investigation of precisely selected evaporation chains in the decay of 24,25Mg

In this proceeding an overview on the NUCLEX scientific campaign aimed at studying the decays of light excited nuclei is presented. After an introduction on the physics case and a description of the adopted experimental strategy, the main results related to the decays of the 24Mg and 25Mg are reported. On both systems, an excess in the fusion-evaporation branching ratios of the channels where only α particles can be emitted has been observed. A possible explanation of the observed non-statistical effects is suggested within a recent application of nuclear time-dependent density functional theor