Initial State Interaction for the 20Ne + 130Te and 18O + 116Sn Systems at 15.3 AMeV from Elastic and Inelastic Scattering Measurements

Abstract

Double charge exchange (DCE) reactions could provide experimentally driven information about nuclear matrix elements of interest in the context of neutrinoless double-β decay. To achieve this goal, a detailed description of the reaction mechanism is mandatory. This requires the full characterization of the initial and final-state interactions, which are poorly known for many of the projectile-target systems involved in future DCE studies. Among these, we intend to study the 20Ne + 130Te and 18O + 116Sn systems at 15.3 AMeV, which are particularly relevant due to their connection with the 130Te→130Xe and 116Cd→116Sn double-β decays. We measure the elastic and inelastic scattering cross-section angular distributions and compare them with theoretical calculations performed in the optical model, one-step distorted wave Born approximation, and coupled-channel approaches using the São Paulo double-folding optical potential. A good description of the experimental data in the whole explored range of transferred momenta is obtained provided that couplings with the 21+ states of the projectile and target are explicitly included within the coupled-channel approach. These results are relevant also in the analysis of other quasi-elastic reaction channels in these systems, in which the same couplings should be included.

A Constrained Analysis of the 40Ca(18O,18F)40K Direct Charge Exchange Reaction Mechanism at 275 MeV

“…The OM and DWBA calculations including São Paulo-derived optical potential describe reasonably well the experimental cross sections at small angles, showing an oscillatory pattern, which is more pronounced than the experimental data and a general overestimation of the data especially at larger angles and momentum transfer (q > 4 fm −1 ). This behavior resembles the one found in the similar analyses (Zagatto et al, 2018;Spatafora et al, 2019;Carbone et al, 2021;La Fauci et al, submitted;Burrello et al, in preparation) and is due to the lack of important couplings of elastic channel with inelastic channels.…”

“…Moreover, the experimental measurement and analysis of the elastic scattering and inelastic scattering cross sections for the same projectile-target system is crucial to constrain the SCE and DCE calculations. Indeed, the projectiletarget nucleus-nucleus potential needs to be accurately modeled both in the entrance [initial state interaction (ISI)] and exit [final state interaction (FSI)] channels (Spatafora et al, 2019;Carbone et al, 2021;La Fauci et al, submitted).…”

The NUMEN Project: Toward New Experiments with High-Intensity Beams

“…The analysis of elastic and inelastic scattering data turned out to be a powerful tool to explore the initial-and final-state interactions in heavy-ion nuclear reactions at high transferred momenta, as has been shown in 76 Ge-76 Se [30][31][32] and in other systems [33]. In the 116 Cd( 20 Ne, 22 Ne) 114 Cd two-neutron pickup and 116 Cd( 20 Ne, 18 O) 118 Sn two-proton stripping reactions at 306 MeV incident energy, selected transitions to low-lying 0+ and 2+ states of the residual nuclei were analyzed.…”

O18 -induced single-nucleon transfer reactions on Ca40 at 15.3<

“…In the present work, the São Paulo double-folding potential (SPP) [53,54] was adopted as the optical potential in the initial and final partitions. Its effectiveness is indeed already well established since it was systematically tested against a wide range of experimental data [55][56][57]. Furthermore, SPP was recently employed to analyze, in optical model (OM), DWBA, and coupled channel (CC) schemes, the elastic and inelastic scattering data collected for the identical colliding system at the same bombarding energy of the experiment here examined [39].…”