Speaker
Description
L. Corradi1, S. Szilner3, G. Andreetta1,2, E.Fioretto1, A. Goasduff1, A. Gottardo1, A. M. Stefanini1, J. J. Valiente-Dobón1, F. Angelini1,2, M. Balogh1, D. Brugnara1, G. de Angelis1, A. Ertoprak1, B. Gongora Servin1, A. Gozzelino1, T. Marchi1, D.R. Napoli1, J. Pellumaj1, R.M. Pérez-Vidal1, M. Sedlak1, D. Stramaccioni1,2, L. Zago1,2, I. Zanon1, P. Aguilera4, J. Benito4, S. Carollo2,4, R. Escudeiro2,4, F. Galtarossa4, S.M. Lenzi2, D. Mengoni2,4, G. Montagnoli2, R. Nicolás del Álamo2,4, S. Pigliapoco4, E. Pilotto2,4, K. Rezynkina4, M. del Fabbro5, J. Diklić3, I. Gasparić3, D. Jelavić Malenica3, I. Lihtar3, T. Mijatović3, L. Palada3, M. Sigmund3, N. Soić3, I. Tišma3, G. Benzoni6, S. Bottoni6,7, A. Bracco6,7, F. Camera6,7, G. Corbari6,7, F. Crespi6,7, E. Gamba6,7, A. Giaz6,7, S. Leoni6,7, B. Million6, O. Wieland6, L. Baldesi8, N. Marchini8, M. Rocchini8, M. Caamaño9 and the AGATA collaboration.
1 Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (PD), Italy
2 Dipartimento di Fisica, Universitá di Padova, Italy
3 Ruder Bošković Institute, Croatia
4 Istituto Nazionale di Fisica Nucleare, Padova, Italy
5 Dipartimento di Fisica e Scienze della Terra, Universitá di Ferrara, Italy
6 Istituto Nazionale di Fisica Nucleare, Milano, Italy
7 Dipartimento di Fisica, Universitá degli Studi di Milano, Italy
8 Istituto Nazionale di Fisica Nucleare, Firenze, Italy
9 Universidade de Santiago de Compostela, Spain
A series of sub-barrier transfer experiments have been recently carried out at LNL, with reaction products detected in inverse kinematic and at forward angles with the large solid angle magnetic spectrometer PRISMA. We measured transfer cross sections far below the Coulomb barrier, making excitation functions down to very low bombarding energies [1-5]. For the (well Q-value matched) one and two neutron transfer channels in the system 60Ni+ 116Sn the microscopic calculations very well reproduce the experimental data in the whole energy range [1-2]. Proton transfer channels have been also analyzed [3], showing the presence of strong proton-proton correlations. These kind of studies, where we followed the behaviour of the transfer probabilities by varying the internuclear distance, turned out to be fundamental to probe nucleon-nucleon correlation effects. In this context, the coupling of the AGATA gamma array to PRISMA offered a unique opportunity to study a nuclear (alternating current (AC)) Josephson-like effect [6], with Cooper-pair tunnelling between superfluid nuclei, whose manifestation has been recently proposed [7] using the data of Refs. [1,2] as a stepping stone. Predictions have been made of a specific gamma strength function associated with the dipole oscillations generated by the, mainly successive, two neutron transfer process. In a very recent experiment carried out at LNL with PRISMA+AGATA we directly tested for the first time the possible manifestation of this important effect of Cooper pair behaviour, observed to date only in condensed matter physics. After a general overview on the subject, the talk will focus on new results, addressing the new achievements and the critical issues
References
[1] D. Montanari et al., Phys. Rev. Lett. 113, 052601 (2014).
[2] D. Montanari et al., Phys. Rev. C 93, 054623 (2016)
[3] L. Corradi et al., Phys. Lett. B 834, 137477 (2022).
[4] S. Szilner et al., Phys. Rev. Lett. 133, 202501 (2024).
[5] L. Corradi, G. Pollarolo, and S. Szilner, J. Phys. G: Nucl. Part. Phys. 36, 113101 (2009).
[6] B.D. Josephson, Phys. Lett. 1, 251 (1962).
[7] G. Potel, F. Barranco, E. Vigezzi, and R. A. Broglia, Phys. Rev. C 103, L021601 (2021).
