The 4He(4He,4He)4He* inelastic scattering was investigated at the MAGNEX facility of INFN - LNS, aiming at shedding light on the characteristics of the isoscalar monopole resonance of 4He which lies ...at an energy slightly higher than the proton emission threshold and slightly lower than the neutron emission threshold. A complementary elastic scattering measurement was also performed to study the initial state interaction and set accurate coupled channel calculations. Here, the experimental setup, the data reduction and the theoretical interpretation strategy are briefly described.
The study of single-nucleon transfer reactions for the 18O+48Ti system was pursued at the energy of 275 MeV as part of a more systematic study which is undertaken within the NUMEN and NURE ...experimental campaigns. The aim is to measure the complete set of available reaction network which are characterized by the same initial and final-state wavefunctions as the more suppressed double charge exchange reactions. Understanding the degree of competition between successive nucleon transfer and double charge exchange reactions is crucial for the description of the meson-exchange mechanism. In this respect, angular distribution measurements for one- and twonucleon transfer reactions for the 18O+48Ti system were carried out at theMAGNEX facility of INFN-LNS in Catania. An overview of the data analysis for the 48Ti(18O,19F)47Sc and 48Ti(18O,17O)49Ti reactions will be presented.
The study of heavy-ions induced double charge-exchange (HI-DCE) nuclear reactions is a promising way to access data-driven information on neutrino-less double-beta decay nuclear matrix elements. In ...the following, particular attention is given to the (18O,18Ne) and (20Ne,20O) HI-DCE reactions as tools for β+β+ and β−β− decays, respectively. The experiments are performed in Catania at the Laboratori Nazionali del Sud of the Istituto Nazionale di Fisica Nucleare (INFN-LNS). The MAGNEX magnetic spectrometer is used to momentum analyse the ejectiles of a large network of nuclear reactions. New preliminary experimental data for the 76Se(18O,18F)76As and 76Ge(20Ne,20F)76As single charge exchange (SCE) and for the 76Se(18O,18Ne)76Ge and 76Ge(20Ne,20O)76Se DCE nuclear reactions were also investigated.
The 18O+48Ti reaction was studied at the energy of 275 MeV for the first time under the NUMEN and NURE experimental campaigns with the aim of investigating the complete reaction network potentially ...involved in the 48Ti→48Ca double charge exchange transition. Understanding the degree of competition between successive nucleon transfer and double charge exchange reactions is crucial for the description of the meson exchange mechanism. Into this context, angular distribution measurements for one- and two-nucleon transfer reactions for the system 18O+48Ti were performed at the MAGNEX facility of INFN-LNS in Catania. An overview of the status of the analysis for the two-proton transfer reaction will be given.
Abstract
Different reactions channels induced by the
18
O +
40
Ca collisions at 275 MeV incident energy are simultaneously measured and analysed consistently within the same reaction and structure ...frameworks within the NUMEN project. The project aims to provide data-driven information for the determination of the nuclear matrix elements involved in the neutrinoless double beta decay. In particular, the elastic and inelastic scattering, one- and two-proton transfer, one-neutron transfer, and single charge exchange reactions are explored. The full quantum-mechanical calculations, performed by including microscopic nuclear structure inputs, describe well all the experimental data, giving support to a multi-channel strategy for the analysis of heavy-ion induced direct reactions.
Heavy-ion one-nucleon transfer reactions are promising tools to investigate single-particle configurations in nuclear states, with and without the excitation of the core degrees of freedom. An ...accurate determination of the spectroscopic amplitudes of these configurations is essential for the study of other direct reactions as well as beta-decays. In this context, the 76Se(18O,17O)77Se one-neutron transfer reaction gives a quantitative access to the relevant single particle orbitals and core polarization transitions built on 76Se. This is particularly relevant, since it provides data-driven information to constrain nuclear structure models for the 76Se nucleus.The excitation energy spectrum and the differential cross section angular distributions of this nucleon transfer reaction was measured at 275 MeV incident energy for the first time using the MAGNEX large acceptance magnetic spectrometer. The data are compared with calculations based on distorted wave Born approximation and coupled channel Born approximation adopting spectroscopic amplitudes for the projectile and target overlaps derived by large-scale shell model calculations and interacting boson-fermion model.These reactions are studied in the frame of the NUMEN project. The NUMEN (NUclear Matrix Elements for Neutrinoless double beta decay) project was conceived at the Istituto Nazionale di Fisica Nucleare–Laboratori Nazionali del Sud (INFN-LNS) in Catania, Italy, aiming at accessing information about the nuclear matrix elements (NME) of neutrinoless double beta decay (0νββ) through the study of the heavy-ion induced double charge exchange (DCE) reactions on various 0νββ decay candidate targets. Among these, the 76Se nucleus is under investigation since it is the daughter nucleus of 76Ge in the 0νββ decay process.
Gamma-ray and neutron spectra from the
18
O
+
76
Se
reaction at 15.3 MeV/u were measured with the EDEN array of liquid scintillators at the LNS. The results were compared to GEANT Hadrontherapy ...physics list simulations in order to assess the reliability of this model for the development of the NUMEN project. A good agreement with the shape of the experimental gamma-ray spectra and a reasonable agreement with the total count rates were obtained. The gamma spectra originated from the nuclear reactions were selected by time coincidence with the Superconducting Cyclotron radio-frequency reference signal. The random coincidence background rate was appropriately described only when the Faraday Cup, the material and geometry of the experimental hall and its contents were included in the simulation with sufficient detail. The information on the radiation spectra is important for the adequate development of the project of the detector arrays and electronic equipment for the advanced phase of NUMEN. Since orders of magnitude larger beam intensities are planned for this phase, the random coincidence rate is also of significant importance, particularly for the performance of the G-NUMEN gamma calorimeter array.
The
40
Ca(
18
O,
18
F)
40
K single charge exchange (SCE) reaction is explored at an incident energy of 275 MeV and analyzed consistently by collecting the elastic scattering and inelastic scattering ...data under the same experimental conditions. Full quantum-mechanical SCE calculations of the direct mechanism are performed by including microscopic nuclear structure inputs and adopting either a bare optical potential or a coupled channel equivalent polarization potential (CCEP) constrained by the elastic and inelastic data. The direct SCE mechanism describes the magnitude and shape of the angular distributions rather well, thus suggesting the suppression of sequential multi-nucleon transfer processes.
The 4He(4He,4He)4He* inelastic scattering was revisited in a new coincidence measurement at the MAGNEX facility of Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud. The 4He + 4He ...→ 4He + 4He* → 4He + 3H + 1H and 4He + 4He → 4He + 4He* → 4He + 3He + n reactions were measured simultaneously by detecting the 4He particles at the MAGNEX magnetic spectrometer in coincidence with the 3H and 3He at the OSCAR silicon telescope. The main concept of the experiment is described and the data reduction strategy is reported.
•Measurement of 20Ne + 130Te double charge exchange reaction.•Nuclear reactions induced by heavy-ion accelerated beams as tools towards the determination of the double beta decay nuclear matrix ...elements.•NUMEN (NUclear Matrix Elements for Neutrinoless double beta decay) project at INFN – LNS.•Heavy-ion induced reactions with the MAGNEX magnetic spectrometer.
The 130Te(20Ne,20O)130Xe double charge exchange reaction was measured for the first time at very forward angles with the MAGNEX magnetic spectrometer at INFN-LNS. The study, performed at beam energy of 306 MeV, is part of a systematic exploration promoted by the NUMEN project. The last aims to measure specific reaction cross sections to provide experimentally driven information about nuclear matrix elements of interest in the context of neutrinoless double beta decay.
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