I present recent AGATA-PRISMA results obtained at Laboratori Nazionali di Legnaro to study the transition into the N = 20 Island of Inversion by multi-nucleon transfer reactions using a 22Ne beam and a 238U target. The experiment aims at exploring the boundaries of the Island of Inversion, following the evolution of negative parity states from the fp shell, locate excited intruder...
Lifetime measurements are commonly used to unravel the nature and properties of nuclear states, as they are closely related to transition probabilities, which provide information on the nuclear wave functions. The aim of the experiment here presented was to study the interplay of spherical (0 ℏω) and intruder (2 ℏω) configurations in the low-lying states of isotopes on the edge of the N=20...
The disappearance of the $N=20$ shell closure in the so-called “island of inversion” around
$^{32}$Mg is one of the most striking examples of the strength of nucleon-nucleon correlations.
In this region, the quadrupole-deformed intruder configuration (based on a multi-particle
multi-hole configuration) becomes the ground state, subverting the expected shell ordering
predicted by a harmonic...
Nuclear shape coexistence plays a crucial role in understanding the microscopic origin of nuclear deformation.
The Ca isotopic chain between $^{40}$Ca and $^{48}$Ca is an optimal test area that can provide key information on shape coexistence when moving from the valley of stability towards the neutron-rich region of the Segrè chart.
This work aims to perform complete low-spin spectroscopy...
Studying the nuclei along and near the N=Z line is the best way to find answers to some fundamental questions in nuclear structure, such as charge-dependence of the nuclear interaction or the role of the proton-neutron pairing. Despite our deep understanding of the electromagnetic interaction, the differences in the binding energies in mirror nuclei cannot be reproduced theoretically, thus...
Neutrinoless double-beta decay is a second-order decay process of atomic nuclei suggested by theories beyond the Standard Model. This decay would constitute the first observation of lepton-number conservation symmetry violation in the laboratory, showing that neutrinos are their own antiparticles. The neutrinoless double-beta decay rate depends on a Nuclear Matrix Element (NME), which is a key...
In this talk, I will present the GAMMA activities at TRIUMF with the GRIFFIN gamma-ray spectrometer. I will describe the facility and the experimental setup, focusing on ongoing and future physics campaigns in different regions of the nuclide chart. Finally, I will introduce future activities at the SPES's beta-decay station.
GEANT4 is a powerful tool to characterize the capabilities of an experimental setup. In this talk, I will present the preliminary results of GEANT4 simulations for two different apparatuses: the Beta decay station, soon to be installed at the INFN laboratories of Legnaro and the Begam project for the study of radiopharmaceuticals.
The beta decay station focuses on studying exotic ions....
Electron spectroscopy is a powerful tool in the investigation of fundamental properties of the atomic nucleus, essential in the study of nuclear structure, where empirical nuclear models provide a framework to understand many nuclear phenomena. The study of electric monopole transitions between nuclear states having the same spin and parity can make an important contribution to clarifying the...
The GRIT European collaboration aims to build a new generation Silicon detector array for optimal study of direct nuclear reactions induced by radioactive-ion beams.
A very brief report on the progress of the analysis of the DSAM experiment studying deformation in $^{56}$Ni using AGATA-OSCAR setup at LNL
An experiment was performed to investigate the octupole collectivity in the $^{96}$Zr isotope, for which the structure of the first $3^-$ state has been widely debated in the literature. Previous measurements suggested that the $\gamma$-ray transition probability for the first $3^-$ state is one of the largest across the nuclear chart. This observation has never been reproduced by any...
About 50% of the elements heavier than iron are produced in the so-called s-process, where the lifetime for neutron capture of the nuclei involved is typically longer than their β-decay lifetimes. In the modeling of the s-process, great uncertainty derives from the competition between neutron capture and β-decay, in particular in some isotopes called “branching points”. $^{85}$Kr is an...
In December 2022, an experiment was performed at INFN-LNL with a $^{208}$Pb beam at 1300 MeV impinging on a $^{9}$Be target, using the inverse kinematics fusion-fission reaction for both nuclear structure and reactions studies. The experiment was performed using the AGATA $\gamma$-ray tracking array coupled to the magnetic spectrometer PRISMA.
This setup allowed one to measure the $\gamma$...
In this contribution, we present our investigation of the shape coexistence phenomenon in Sn isotopes around A=110, by means of $\gamma$-ray spectroscopy and lifetime measurements of low-spin states. Recent observation of axially deformed $0^+$ states in $^{64,66}$Ni isotopes suggested the possibility of having similar excitations in the stable Sn isotopes, across the $Z=50$ shell gap, due to...
Large-volume scintillator detectors are used in nuclear physics experiments with high-energy gamma rays. In this paper, I’m presenting the R&D work performed in Milano on scintillators and their employment in collective motion experiments. There are two main activities in Milan: the first one regards the CLYC scintillators, focused on their fast neutron efficiency, whereas the second is on the...
During the past year, the EXOTIC facility underwent several upgrades, including the installation of newly developed Micro-Channel Plates (MCPs). This enables the event-by-event identification of the radioactive ion beam by the two detectors positioned upstream of the AGATA target chamber. The present setup facilitates the tracking of incoming particles, thereby enabling the separation of the...
In the 1950s, Devons et al. started to carry out experiments in light nuclei that aimed to measure the angular distribution of the relative angle in the emission of the leptons in the Internal Pair Creation (IPC) process. The results were consistent with the Model of Rose published in 1949. In 2016, Krasznahorkay et al. reported the breakthrough of an anomaly in the IPC of $^8$Be. An...
Nuclear structure is a challenging topic as we deal with systems that are not small enough to use standard quantum methods, nor large enough for statistical mechanics. Nuclei with similar numbers of neutrons and protons ($N \approx Z$) exhibit competition between different shapes, such as oblate and prolate, leading to phenomena like shape coexistence. These $N \approx Z$ nuclei are...
A novel technique has been developed to measure lifetimes of heavy neutron-rich nuclei, namely 'the reversed plunger'. In heavy neutron-rich nuclei, information on the lifetimes of low-lying excited states is scarce since these nuclei are difficult to populate. Among different reaction mechanisms, multi-nucleon transfer reactions have shown to be the perfect tool to explore such regions....
The work presented is focused on experimental results from two experiments performed using the FRS+DESPEC setup at GSI-FAIR in spring 2021 The two experiments aimed at studying two different regions of the nuclear chart, extending from the heavy n-rich side around A$\sim$225 towards the p-rich $^{100}$Sn region.
The main results from the analysis of the heavy n-rich region is the first...
The pairing interaction, responsible for the two-nucleon correlation, plays a fundamental role in defining the low-energy spectra of atomic nuclei and the properties of their ground state. The effect of pairing correlations in the reaction dynamics can be explored by using heavy-ion reactions, in particular those involving a transfer of few nucleons. In this context, an interesting analogy...
The higher counting-rate and radiation hardness required by modern gamma spectroscopy experiments highlight the need for a new generation of High-Purity Germanium (HPGe) detectors based on electrons-collecting electrodes. To achieve this goal, a new doping technology, the Pulsed Laser Melting (PLM), has been developed. This technique is being applied to coaxial detectors in the framework of...
A brief presentation about available ancillary detectors at LNL, use cases, optimization processes and future plans.
The present work reports the status of lifetime measurements and in-beam spectroscopy of neutron-rich Pt isotopes. The experiment aims to study the shape evolution in this region. These nuclei are expected to be more spherical near shell closure, but there is a lack of data to support this theoretical prediction. The population of the states of interest has been carried out by the...
