Orateur
Description
N.S. Martorana $^1$, G. Cardella$^1$, E.G. Lanza$^1$, A. Barbon$^{1,2}$, A. Castoldi$^3$, G. D’Agata$^{1,2}$, E. De Filippo $^1$, E. Geraci$^{1,2}$, B. Gnoffo$^{1,2}$, C. Guazzoni$^{3}$, C. Maiolino$^{4}$, E.V. Pagano$^{4}$, M. Papa$^{1}$, S. Pirrone$^{1}$, G. Politi$^{1,2}$, L. Quattrocchi$^{1,5}$, F. Risitano$^{1,5}$, F. Rizzo$^{2,4,6}$, P. Russotto$^{4}$, M. Trimarchi$^{1,5}$, C. Zagami $^{2,4,6}$
1 INFN-Sezione di Catania, Catania, Italy
2 Dipartimento di Fisica e Astronomia “Ettore Majorana”, Università degli Studi di Catania, Catania, Italy
3 DEIB Politecnico Milano and INFN Sez. Milano, Milano, Italy
4 INFN-LNS, Catania, Italy
5 Dipartimento MIFT, Università di Messina, Messina, Italy
6 CSFNSM, Catania, Italy
Studies of the low-lying E1 strength around the nucleon binding energy, historically known as Pygmy Dipole Resonance (PDR), are among the most intriguing nuclear structure issues. The PDR is an excitation mode connected to the neutron excess in nuclei, and its strength is more intense in nuclei far from the stability with respect to the stable ones. The interest in a deep understanding of this mode arises also for the strong connection with the neutron skin and with the symmetry energy term of the equation of state of the nuclear matter (EoS) [1-3]. One of the major task of experimental and theoretical investigations is the determination of a consistent density parametrization of the symmetry energy, which can provide a unified picture of nuclear properties. Indeed, several features of nuclei as well as of the neutron stars can be obtained through the constrain of the symmetry energy term [4]. One of the most important feature of the PDR is the isospin mixing effect [1-3]. Due to this effect, as shown in several stable nuclei and in few unstable ones, the PDR excitation can be populated with both isoscalar and isovector probes [2-3]. However, some of its properties, as the degree of collectivity, are still under debate. In order to better understand the nature of the PDR it is necessary to perform investigations using both probes in different mass regions and above and below the neutron emission threshold. In this contribution, results about PDR studies, within its implications on the symmetry energy, will be discussed. Furthermore, a special focus will be given on the measurement performed in Catania, at INFN-LNS, studying the PDR 𝛾-decay in 68Ni [5]. Future perspectives aiming at a better understanding of the PDR using the FRaISe facility, in construction at INFN-LNS, will be discussed. A new SiC tagging system, developed in the framework of INFN-Sezione di Catania activities in the SAMOTHRACE ecosystem, will be presented in detail [6-7]. This work has been partially supported by SAMOTHRACE ecosystem [7].
[1] C. Agodi, F. Cappuzzello, G. Cardella et al. Eur. Phys. J. Plus 138, 1038 (2023) and references therein
[2] A. Bracco et al., Progr. in Particle and Nuclear Physics 106, 360-433 (2019) and references therein
[3] D. Savran et al., Progr. in Particle and Nuclear Physics 70, 210-245 (2013)
[4] A. Sorensen et al., Progr. in Particle and Nuclear Physics 134, 104080 (2024) and references therein
[5] N.S. Martorana et al., Physics Letters B 782, 112 116 (2018)
[6] N.S. Martorana et al., Frontiers in Physics, 10 (2022) and references therein
[7] www.samothrace.eu
